xref: /dragonfly/libexec/ftpd/ftpd.c (revision 4093b119b16f73c976f5a4d8ac6cda5457f76d7a)
1 /*
2  * Copyright (c) 1985, 1988, 1990, 1992, 1993, 1994
3  *        The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * @(#)ftpd.c       8.4 (Berkeley) 4/16/94
30  * $FreeBSD: src/libexec/ftpd/ftpd.c,v 1.213 2008/12/23 01:23:09 cperciva Exp $
31  */
32 
33 /*
34  * FTP server.
35  */
36 #include <sys/param.h>
37 #include <sys/ioctl.h>
38 #include <sys/mman.h>
39 #include <sys/socket.h>
40 #include <sys/stat.h>
41 #include <sys/time.h>
42 #include <sys/wait.h>
43 
44 #include <netinet/in.h>
45 #include <netinet/in_systm.h>
46 #include <netinet/ip.h>
47 #include <netinet/tcp.h>
48 
49 #define   FTP_NAMES
50 #include <arpa/ftp.h>
51 #include <arpa/inet.h>
52 #include <arpa/telnet.h>
53 
54 #include <ctype.h>
55 #include <dirent.h>
56 #include <err.h>
57 #include <errno.h>
58 #include <fcntl.h>
59 #include <glob.h>
60 #include <limits.h>
61 #include <netdb.h>
62 #include <pwd.h>
63 #include <grp.h>
64 #include <signal.h>
65 #include <stdint.h>
66 #include <stdio.h>
67 #include <stdlib.h>
68 #include <string.h>
69 #include <syslog.h>
70 #include <time.h>
71 #include <unistd.h>
72 #include <libutil.h>
73 #ifdef    LOGIN_CAP
74 #include <login_cap.h>
75 #endif
76 
77 #ifdef USE_PAM
78 #include <security/pam_appl.h>
79 #endif
80 
81 #include "pathnames.h"
82 #include "extern.h"
83 
84 #include <stdarg.h>
85 
86 static char version[] = "Version 6.00LS";
87 #undef main
88 
89 extern    off_t restart_point;
90 extern    char cbuf[];
91 
92 union sockunion ctrl_addr;
93 union sockunion data_source;
94 union sockunion data_dest;
95 union sockunion his_addr;
96 union sockunion pasv_addr;
97 
98 int       daemon_mode;
99 int       data;
100 int       dataport;
101 int       hostinfo = 1;       /* print host-specific info in messages */
102 int       logged_in;
103 struct    passwd *pw;
104 char      *homedir;
105 int       ftpdebug;
106 int       timeout = 900;    /* timeout after 15 minutes of inactivity */
107 int       maxtimeout = 7200;/* don't allow idle time to be set beyond 2 hours */
108 int       logging;
109 int       restricted_data_ports = 1;
110 int       paranoid = 1;         /* be extra careful about security */
111 int       anon_only = 0;    /* Only anonymous ftp allowed */
112 int       assumeutf8 = 0;   /* Assume that server file names are in UTF-8 */
113 int       guest;
114 int       dochroot;
115 char      *chrootdir;
116 int       dowtmpx = 1;
117 int       stats;
118 int       statfd = -1;
119 int       type;
120 int       form;
121 int       stru;                         /* avoid C keyword */
122 int       mode;
123 int       usedefault = 1;               /* for data transfers */
124 int       pdata = -1;                   /* for passive mode */
125 int       readonly = 0;                 /* Server is in readonly mode.          */
126 int       noepsv = 0;                   /* EPSV command is disabled.  */
127 int       noretr = 0;                   /* RETR command is disabled.  */
128 int       noguestretr = 0;    /* RETR command is disabled for anon users. */
129 int       noguestmkd = 0;               /* MKD command is disabled for anon users. */
130 int       noguestmod = 1;               /* anon users may not modify existing files. */
131 
132 off_t     file_size;
133 off_t     byte_count;
134 #if !defined(CMASK) || CMASK == 0
135 #undef CMASK
136 #define CMASK 027
137 #endif
138 int       defumask = CMASK;             /* default umask value */
139 char      tmpline[7];
140 char      *hostname;
141 int       epsvall = 0;
142 
143 #ifdef VIRTUAL_HOSTING
144 char      *ftpuser;
145 
146 static struct ftphost {
147           struct ftphost      *next;
148           struct addrinfo *hostinfo;
149           char                *hostname;
150           char                *anonuser;
151           char                *statfile;
152           char                *welcome;
153           char                *loginmsg;
154 } *thishost, *firsthost;
155 
156 #endif
157 char      remotehost[NI_MAXHOST];
158 char      *ident = NULL;
159 
160 static char         ttyline[20];
161 char                *tty = ttyline;               /* for klogin */
162 
163 #ifdef USE_PAM
164 static int          auth_pam(struct passwd**, const char*);
165 pam_handle_t        *pamh = NULL;
166 #endif
167 
168 static int                    pwok;
169 
170 char      *pid_file = NULL; /* means default location to pidfile(3) */
171 
172 /*
173  * Limit number of pathnames that glob can return.
174  * A limit of 0 indicates the number of pathnames is unlimited.
175  */
176 #define MAXGLOBARGS 16384
177 
178 /*
179  * Timeout intervals for retrying connections
180  * to hosts that don't accept PORT cmds.  This
181  * is a kludge, but given the problems with TCP...
182  */
183 #define   SWAITMAX  90        /* wait at most 90 seconds */
184 #define   SWAITINT  5         /* interval between retries */
185 
186 int       swaitmax = SWAITMAX;
187 int       swaitint = SWAITINT;
188 
189 #ifdef SETPROCTITLE
190 char      proctitle[LINE_MAX];          /* initial part of title */
191 #endif /* SETPROCTITLE */
192 
193 #define LOGCMD(cmd, file)               logcmd((cmd), (file), NULL, -1)
194 #define LOGCMD2(cmd, file1, file2)      logcmd((cmd), (file1), (file2), -1)
195 #define LOGBYTES(cmd, file, cnt)        logcmd((cmd), (file), NULL, (cnt))
196 
197 static    volatile sig_atomic_t recvurg;
198 static    int transflag;                /* NB: for debugging only */
199 
200 #define STARTXFER   flagxfer(1)
201 #define ENDXFER               flagxfer(0)
202 
203 #define START_UNSAFE          maskurg(1)
204 #define END_UNSAFE  maskurg(0)
205 
206 /* It's OK to put an `else' clause after this macro. */
207 #define CHECKOOB(action)                                                        \
208           if (recvurg) {                                                                  \
209                     recvurg = 0;                                                          \
210                     if (myoob()) {                                                        \
211                               ENDXFER;                                          \
212                               action;                                                     \
213                     }                                                                     \
214           }
215 
216 #ifdef VIRTUAL_HOSTING
217 static void          inithosts(int);
218 static void          selecthost(union sockunion *);
219 #endif
220 static void          ack(char *);
221 static void          sigurg(int);
222 static void          maskurg(int);
223 static void          flagxfer(int);
224 static int           myoob(void);
225 static int           checkuser(char *, char *, int, char **);
226 static FILE         *dataconn(char *, off_t, char *);
227 static void          dolog(struct sockaddr *);
228 static void          end_login(void);
229 static FILE         *getdatasock(char *);
230 static int           guniquefd(char *, char **);
231 static void          lostconn(int);
232 static void          sigquit(int);
233 static int           receive_data(FILE *, FILE *);
234 static int           send_data(FILE *, FILE *, size_t, off_t, int);
235 static struct passwd *
236                      sgetpwnam(char *);
237 static char         *sgetsave(char *);
238 static void          reapchild(int);
239 static void          appendf(char **, char *, ...) __printflike(2, 3);
240 static void          logcmd(char *, char *, char *, off_t);
241 static void      logxfer(char *, off_t, time_t);
242 static char         *doublequote(char *);
243 static int          *socksetup(int, char *, const char *);
244 
245 int
main(int argc,char * argv[])246 main(int argc, char *argv[])
247 {
248           socklen_t addrlen;
249           int ch, on = 1, tos;
250           char *cp, line[LINE_MAX];
251           FILE *fd;
252           char      *bindname = NULL;
253           const char *bindport = "ftp";
254           int       family = AF_UNSPEC;
255           struct sigaction sa;
256 
257           tzset();            /* in case no timezone database in ~ftp */
258           sigemptyset(&sa.sa_mask);
259           sa.sa_flags = SA_RESTART;
260 
261           /*
262            * Prevent diagnostic messages from appearing on stderr.
263            * We run as a daemon or from inetd; in both cases, there's
264            * more reason in logging to syslog.
265            */
266           freopen(_PATH_DEVNULL, "w", stderr);
267           opterr = 0;
268 
269           /*
270            * LOG_NDELAY sets up the logging connection immediately,
271            * necessary for anonymous ftp's that chroot and can't do it later.
272            */
273           openlog("ftpd", LOG_PID | LOG_NDELAY, LOG_FTP);
274 
275           while ((ch = getopt(argc, argv,
276                               "468a:AdDEH:hlmMoOp:P:rRSt:T:u:UvW")) != -1) {
277                     switch (ch) {
278                     case '4':
279                               family = (family == AF_INET6) ? AF_UNSPEC : AF_INET;
280                               break;
281 
282                     case '6':
283                               family = (family == AF_INET) ? AF_UNSPEC : AF_INET6;
284                               break;
285 
286                     case '8':
287                               assumeutf8 = 1;
288                               break;
289 
290                     case 'a':
291                               bindname = optarg;
292                               break;
293 
294                     case 'A':
295                               anon_only = 1;
296                               break;
297 
298                     case 'd':
299                               ftpdebug++;
300                               break;
301 
302                     case 'D':
303                               daemon_mode++;
304                               break;
305 
306                     case 'E':
307                               noepsv = 1;
308                               break;
309 
310                     case 'h':
311                               hostinfo = 0;
312                               break;
313 
314                     case 'H':
315                               hostname = optarg;
316                               break;
317 
318                     case 'l':
319                               logging++;          /* > 1 == extra logging */
320                               break;
321 
322                     case 'm':
323                               noguestmod = 0;
324                               break;
325 
326                     case 'M':
327                               noguestmkd = 1;
328                               break;
329 
330                     case 'o':
331                               noretr = 1;
332                               break;
333 
334                     case 'O':
335                               noguestretr = 1;
336                               break;
337 
338                     case 'p':
339                               pid_file = optarg;
340                               break;
341 
342                     case 'P':
343                               bindport = optarg;
344                               break;
345 
346                     case 'r':
347                               readonly = 1;
348                               break;
349 
350                     case 'R':
351                               paranoid = 0;
352                               break;
353 
354                     case 'S':
355                               stats++;
356                               break;
357 
358                     case 't':
359                               timeout = atoi(optarg);
360                               if (maxtimeout < timeout)
361                                         maxtimeout = timeout;
362                               break;
363 
364                     case 'T':
365                               maxtimeout = atoi(optarg);
366                               if (timeout > maxtimeout)
367                                         timeout = maxtimeout;
368                               break;
369 
370                     case 'u':
371                         {
372                               long val = 0;
373 
374                               val = strtol(optarg, &optarg, 8);
375                               if (*optarg != '\0' || val < 0)
376                                         syslog(LOG_WARNING, "bad value for -u");
377                               else
378                                         defumask = val;
379                               break;
380                         }
381                     case 'U':
382                               restricted_data_ports = 0;
383                               break;
384 
385                     case 'v':
386                               ftpdebug++;
387                               break;
388 
389                     case 'W':
390                               dowtmpx = 0;
391                               break;
392 
393                     default:
394                               syslog(LOG_WARNING, "unknown flag -%c ignored", optopt);
395                               break;
396                     }
397           }
398 
399           if (daemon_mode) {
400                     int *ctl_sock, fd, maxfd = -1, nfds, i;
401                     fd_set defreadfds, readfds;
402                     pid_t pid;
403                     struct pidfh *pfh;
404 
405                     if ((pfh = pidfile_open(pid_file, 0600, &pid)) == NULL) {
406                               if (errno == EEXIST) {
407                                         syslog(LOG_ERR, "%s already running, pid %d",
408                                                getprogname(), (int)pid);
409                                         exit(1);
410                               }
411                               syslog(LOG_WARNING, "pidfile_open: %m");
412                     }
413 
414                     /*
415                      * Detach from parent.
416                      */
417                     if (daemon(1, 1) < 0) {
418                               syslog(LOG_ERR, "failed to become a daemon");
419                               exit(1);
420                     }
421 
422                     if (pfh != NULL && pidfile_write(pfh) == -1)
423                               syslog(LOG_WARNING, "pidfile_write: %m");
424 
425                     sa.sa_handler = reapchild;
426                     sigaction(SIGCHLD, &sa, NULL);
427 
428 #ifdef VIRTUAL_HOSTING
429                     inithosts(family);
430 #endif
431 
432                     /*
433                      * Open a socket, bind it to the FTP port, and start
434                      * listening.
435                      */
436                     ctl_sock = socksetup(family, bindname, bindport);
437                     if (ctl_sock == NULL)
438                               exit(1);
439 
440                     FD_ZERO(&defreadfds);
441                     for (i = 1; i <= *ctl_sock; i++) {
442                               FD_SET(ctl_sock[i], &defreadfds);
443                               if (listen(ctl_sock[i], 32) < 0) {
444                                         syslog(LOG_ERR, "control listen: %m");
445                                         exit(1);
446                               }
447                               if (maxfd < ctl_sock[i])
448                                         maxfd = ctl_sock[i];
449                     }
450 
451                     /*
452                      * Loop forever accepting connection requests and forking off
453                      * children to handle them.
454                      */
455                     while (1) {
456                               FD_COPY(&defreadfds, &readfds);
457                               nfds = select(maxfd + 1, &readfds, NULL, NULL, 0);
458                               if (nfds <= 0) {
459                                         if (nfds < 0 && errno != EINTR)
460                                                   syslog(LOG_WARNING, "select: %m");
461                                         continue;
462                               }
463 
464                               pid = -1;
465                         for (i = 1; i <= *ctl_sock; i++)
466                                         if (FD_ISSET(ctl_sock[i], &readfds)) {
467                                                   addrlen = sizeof(his_addr);
468                                                   fd = accept(ctl_sock[i],
469                                                       (struct sockaddr *)&his_addr,
470                                                       &addrlen);
471                                                   if (fd == -1) {
472                                                             syslog(LOG_WARNING,
473                                                                    "accept: %m");
474                                                             continue;
475                                                   }
476                                                   switch (pid = fork()) {
477                                                   case 0:
478                                                             /* child */
479                                                             dup2(fd, 0);
480                                                             dup2(fd, 1);
481                                                             close(fd);
482                                                             for (i = 1; i <= *ctl_sock; i++)
483                                                                       close(ctl_sock[i]);
484                                                             if (pfh != NULL)
485                                                                       pidfile_close(pfh);
486                                                             goto gotchild;
487                                                   case -1:
488                                                             syslog(LOG_WARNING, "fork: %m");
489                                                             /* FALLTHROUGH */
490                                                   default:
491                                                             close(fd);
492                                                   }
493                                         }
494                     }
495           } else {
496                     addrlen = sizeof(his_addr);
497                     if (getpeername(0, (struct sockaddr *)&his_addr, &addrlen) < 0) {
498                               syslog(LOG_ERR, "getpeername (%s): %m",argv[0]);
499                               exit(1);
500                     }
501 
502 #ifdef VIRTUAL_HOSTING
503                     if (his_addr.su_family == AF_INET6 &&
504                         IN6_IS_ADDR_V4MAPPED(&his_addr.su_sin6.sin6_addr))
505                               family = AF_INET;
506                     else
507                               family = his_addr.su_family;
508                     inithosts(family);
509 #endif
510           }
511 
512 gotchild:
513           sa.sa_handler = SIG_DFL;
514           sigaction(SIGCHLD, &sa, NULL);
515 
516           sa.sa_handler = sigurg;
517           sa.sa_flags = 0;              /* don't restart syscalls for SIGURG */
518           sigaction(SIGURG, &sa, NULL);
519 
520           sigfillset(&sa.sa_mask);      /* block all signals in handler */
521           sa.sa_flags = SA_RESTART;
522           sa.sa_handler = sigquit;
523           sigaction(SIGHUP, &sa, NULL);
524           sigaction(SIGINT, &sa, NULL);
525           sigaction(SIGQUIT, &sa, NULL);
526           sigaction(SIGTERM, &sa, NULL);
527 
528           sa.sa_handler = lostconn;
529           sigaction(SIGPIPE, &sa, NULL);
530 
531           addrlen = sizeof(ctrl_addr);
532           if (getsockname(0, (struct sockaddr *)&ctrl_addr, &addrlen) < 0) {
533                     syslog(LOG_ERR, "getsockname (%s): %m",argv[0]);
534                     exit(1);
535           }
536           dataport = ntohs(ctrl_addr.su_port) - 1; /* as per RFC 959 */
537 #ifdef VIRTUAL_HOSTING
538           /* select our identity from virtual host table */
539           selecthost(&ctrl_addr);
540 #endif
541 #ifdef IP_TOS
542           if (ctrl_addr.su_family == AF_INET)
543       {
544           tos = IPTOS_LOWDELAY;
545           if (setsockopt(0, IPPROTO_IP, IP_TOS, &tos, sizeof(int)) < 0)
546                     syslog(LOG_WARNING, "control setsockopt (IP_TOS): %m");
547       }
548 #endif
549           /*
550            * Disable Nagle on the control channel so that we don't have to wait
551            * for peer's ACK before issuing our next reply.
552            */
553           if (setsockopt(0, IPPROTO_TCP, TCP_NODELAY, &on, sizeof(on)) < 0)
554                     syslog(LOG_WARNING, "control setsockopt (TCP_NODELAY): %m");
555 
556           data_source.su_port = htons(ntohs(ctrl_addr.su_port) - 1);
557 
558           /* set this here so klogin can use it... */
559           snprintf(ttyline, sizeof(ttyline), "ftp%d", getpid());
560 
561           /* Try to handle urgent data inline */
562 #ifdef SO_OOBINLINE
563           if (setsockopt(0, SOL_SOCKET, SO_OOBINLINE, &on, sizeof(on)) < 0)
564                     syslog(LOG_WARNING, "control setsockopt (SO_OOBINLINE): %m");
565 #endif
566 
567 #ifdef    F_SETOWN
568           if (fcntl(fileno(stdin), F_SETOWN, getpid()) == -1)
569                     syslog(LOG_ERR, "fcntl F_SETOWN: %m");
570 #endif
571           dolog((struct sockaddr *)&his_addr);
572           /*
573            * Set up default state
574            */
575           data = -1;
576           type = TYPE_A;
577           form = FORM_N;
578           stru = STRU_F;
579           mode = MODE_S;
580           tmpline[0] = '\0';
581 
582           /* If logins are disabled, print out the message. */
583           if ((fd = fopen(_PATH_NOLOGIN,"r")) != NULL) {
584                     while (fgets(line, sizeof(line), fd) != NULL) {
585                               if ((cp = strchr(line, '\n')) != NULL)
586                                         *cp = '\0';
587                               lreply(530, "%s", line);
588                     }
589                     fflush(stdout);
590                     fclose(fd);
591                     reply(530, "System not available.");
592                     exit(0);
593           }
594 #ifdef VIRTUAL_HOSTING
595           fd = fopen(thishost->welcome, "r");
596 #else
597           fd = fopen(_PATH_FTPWELCOME, "r");
598 #endif
599           if (fd != NULL) {
600                     while (fgets(line, sizeof(line), fd) != NULL) {
601                               if ((cp = strchr(line, '\n')) != NULL)
602                                         *cp = '\0';
603                               lreply(220, "%s", line);
604                     }
605                     fflush(stdout);
606                     fclose(fd);
607                     /* reply(220,) must follow */
608           }
609 #ifndef VIRTUAL_HOSTING
610           if (hostname == NULL) {
611                     if ((hostname = malloc(MAXHOSTNAMELEN)) == NULL)
612                               fatalerror("Ran out of memory.");
613                     if (gethostname(hostname, MAXHOSTNAMELEN - 1) < 0)
614                               hostname[0] = '\0';
615                     hostname[MAXHOSTNAMELEN - 1] = '\0';
616           }
617 #endif
618           if (hostinfo)
619                     reply(220, "%s FTP server (%s) ready.", hostname, version);
620           else
621                     reply(220, "FTP server ready.");
622           for (;;)
623                     yyparse();
624           /* NOTREACHED */
625 }
626 
627 static void
lostconn(int signo)628 lostconn(int signo)
629 {
630 
631           if (ftpdebug)
632                     syslog(LOG_DEBUG, "lost connection");
633           dologout(1);
634 }
635 
636 static void
sigquit(int signo)637 sigquit(int signo)
638 {
639 
640           syslog(LOG_ERR, "got signal %d", signo);
641           dologout(1);
642 }
643 
644 #ifdef VIRTUAL_HOSTING
645 /*
646  * read in virtual host tables (if they exist)
647  */
648 
649 static void
inithosts(int family)650 inithosts(int family)
651 {
652           int insert;
653           size_t len;
654           FILE *fp;
655           char *cp, *mp, *line;
656           char *vhost, *anonuser, *statfile, *welcome, *loginmsg;
657           struct ftphost *hrp, *lhrp;
658           struct addrinfo hints, *res, *ai;
659 
660           /*
661            * Fill in the default host information
662            */
663           if (hostname == NULL) {
664                     if ((hostname = malloc(MAXHOSTNAMELEN)) == NULL)
665                               fatalerror("Ran out of memory.");
666                     if (gethostname(hostname, MAXHOSTNAMELEN - 1) < 0)
667                               hostname[0] = '\0';
668                     hostname[MAXHOSTNAMELEN - 1] = '\0';
669           }
670           if ((hrp = malloc(sizeof(struct ftphost))) == NULL)
671                     fatalerror("Ran out of memory.");
672           hrp->hostname = hostname;
673           hrp->hostinfo = NULL;
674 
675           memset(&hints, 0, sizeof(hints));
676           hints.ai_flags = AI_PASSIVE;
677           hints.ai_family = family;
678           hints.ai_socktype = SOCK_STREAM;
679           if (getaddrinfo(hrp->hostname, NULL, &hints, &res) == 0)
680                     hrp->hostinfo = res;
681           hrp->statfile = _PATH_FTPDSTATFILE;
682           hrp->welcome  = _PATH_FTPWELCOME;
683           hrp->loginmsg = _PATH_FTPLOGINMESG;
684           hrp->anonuser = "ftp";
685           hrp->next = NULL;
686           thishost = firsthost = lhrp = hrp;
687           if ((fp = fopen(_PATH_FTPHOSTS, "r")) != NULL) {
688                     int addrsize, gothost;
689                     void *addr;
690                     struct hostent *hp;
691 
692                     while ((line = fgetln(fp, &len)) != NULL) {
693                               int       i, hp_error;
694 
695                               /* skip comments */
696                               if (line[0] == '#')
697                                         continue;
698                               if (line[len - 1] == '\n') {
699                                         line[len - 1] = '\0';
700                                         mp = NULL;
701                               } else {
702                                         if ((mp = malloc(len + 1)) == NULL)
703                                                   fatalerror("Ran out of memory.");
704                                         memcpy(mp, line, len);
705                                         mp[len] = '\0';
706                                         line = mp;
707                               }
708                               cp = strtok(line, " \t");
709                               /* skip empty lines */
710                               if (cp == NULL)
711                                         goto nextline;
712                               vhost = cp;
713 
714                               /* set defaults */
715                               anonuser = "ftp";
716                               statfile = _PATH_FTPDSTATFILE;
717                               welcome  = _PATH_FTPWELCOME;
718                               loginmsg = _PATH_FTPLOGINMESG;
719 
720                               /*
721                                * Preparse the line so we can use its info
722                                * for all the addresses associated with
723                                * the virtual host name.
724                                * Field 0, the virtual host name, is special:
725                                * it's already parsed off and will be strdup'ed
726                                * later, after we know its canonical form.
727                                */
728                               for (i = 1; i < 5 && (cp = strtok(NULL, " \t")); i++)
729                                         if (*cp != '-' && (cp = strdup(cp)))
730                                                   switch (i) {
731                                                   case 1:   /* anon user permissions */
732                                                             anonuser = cp;
733                                                             break;
734                                                   case 2: /* statistics file */
735                                                             statfile = cp;
736                                                             break;
737                                                   case 3: /* welcome message */
738                                                             welcome  = cp;
739                                                             break;
740                                                   case 4: /* login message */
741                                                             loginmsg = cp;
742                                                             break;
743                                                   default: /* programming error */
744                                                             abort();
745                                                             /* NOTREACHED */
746                                                   }
747 
748                               hints.ai_flags = AI_PASSIVE;
749                               hints.ai_family = family;
750                               hints.ai_socktype = SOCK_STREAM;
751                               if (getaddrinfo(vhost, NULL, &hints, &res) != 0)
752                                         goto nextline;
753                               for (ai = res; ai != NULL && ai->ai_addr != NULL;
754                                    ai = ai->ai_next) {
755 
756                               gothost = 0;
757                               for (hrp = firsthost; hrp != NULL; hrp = hrp->next) {
758                                         struct addrinfo *hi;
759 
760                                         for (hi = hrp->hostinfo; hi != NULL;
761                                              hi = hi->ai_next)
762                                                   if (hi->ai_addrlen == ai->ai_addrlen &&
763                                                       memcmp(hi->ai_addr,
764                                                                ai->ai_addr,
765                                                                ai->ai_addr->sa_len) == 0) {
766                                                             gothost++;
767                                                             break;
768                                                   }
769                                         if (gothost)
770                                                   break;
771                               }
772                               if (hrp == NULL) {
773                                         if ((hrp = malloc(sizeof(struct ftphost))) == NULL)
774                                                   goto nextline;
775                                         hrp->hostname = NULL;
776                                         insert = 1;
777                               } else {
778                                         if (hrp->hostinfo && hrp->hostinfo != res)
779                                                   freeaddrinfo(hrp->hostinfo);
780                                         insert = 0; /* host already in the chain */
781                               }
782                               hrp->hostinfo = res;
783 
784                               /*
785                                * determine hostname to use.
786                                * force defined name if there is a valid alias
787                                * otherwise fallback to primary hostname
788                                */
789                               /* XXX: getaddrinfo() can't do alias check */
790                               switch(hrp->hostinfo->ai_family) {
791                               case AF_INET:
792                                         addr = &((struct sockaddr_in *)hrp->hostinfo->ai_addr)->sin_addr;
793                                         addrsize = sizeof(struct in_addr);
794                                         break;
795                               case AF_INET6:
796                                         addr = &((struct sockaddr_in6 *)hrp->hostinfo->ai_addr)->sin6_addr;
797                                         addrsize = sizeof(struct in6_addr);
798                                         break;
799                               default:
800                                         /* should not reach here */
801                                         freeaddrinfo(hrp->hostinfo);
802                                         if (insert)
803                                                   free(hrp); /*not in chain, can free*/
804                                         else
805                                                   hrp->hostinfo = NULL; /*mark as blank*/
806                                         goto nextline;
807                                         /* NOTREACHED */
808                               }
809                               if ((hp = getipnodebyaddr(addr, addrsize,
810                                                               hrp->hostinfo->ai_family,
811                                                               &hp_error)) != NULL) {
812                                         if (strcmp(vhost, hp->h_name) != 0) {
813                                                   if (hp->h_aliases == NULL)
814                                                             vhost = hp->h_name;
815                                                   else {
816                                                             i = 0;
817                                                             while (hp->h_aliases[i] &&
818                                                                    strcmp(vhost, hp->h_aliases[i]) != 0)
819                                                                       ++i;
820                                                             if (hp->h_aliases[i] == NULL)
821                                                                       vhost = hp->h_name;
822                                                   }
823                                         }
824                               }
825                               if (hrp->hostname &&
826                                   strcmp(hrp->hostname, vhost) != 0) {
827                                         free(hrp->hostname);
828                                         hrp->hostname = NULL;
829                               }
830                               if (hrp->hostname == NULL &&
831                                   (hrp->hostname = strdup(vhost)) == NULL) {
832                                         freeaddrinfo(hrp->hostinfo);
833                                         hrp->hostinfo = NULL; /* mark as blank */
834                                         if (hp)
835                                                   freehostent(hp);
836                                         goto nextline;
837                               }
838                               hrp->anonuser = anonuser;
839                               hrp->statfile = statfile;
840                               hrp->welcome  = welcome;
841                               hrp->loginmsg = loginmsg;
842                               if (insert) {
843                                         hrp->next  = NULL;
844                                         lhrp->next = hrp;
845                                         lhrp = hrp;
846                               }
847                               if (hp)
848                                         freehostent(hp);
849                           }
850 nextline:
851                               if (mp)
852                                         free(mp);
853                     }
854                     fclose(fp);
855           }
856 }
857 
858 static void
selecthost(union sockunion * su)859 selecthost(union sockunion *su)
860 {
861           struct ftphost      *hrp;
862           u_int16_t port;
863 #ifdef INET6
864           struct in6_addr *mapped_in6 = NULL;
865 #endif
866           struct addrinfo *hi;
867 
868 #ifdef INET6
869           /*
870            * XXX IPv4 mapped IPv6 addr consideraton,
871            * specified in rfc2373.
872            */
873           if (su->su_family == AF_INET6 &&
874               IN6_IS_ADDR_V4MAPPED(&su->su_sin6.sin6_addr))
875                     mapped_in6 = &su->su_sin6.sin6_addr;
876 #endif
877 
878           hrp = thishost = firsthost;   /* default */
879           port = su->su_port;
880           su->su_port = 0;
881           while (hrp != NULL) {
882               for (hi = hrp->hostinfo; hi != NULL; hi = hi->ai_next) {
883                     if (memcmp(su, hi->ai_addr, hi->ai_addrlen) == 0) {
884                               thishost = hrp;
885                               goto found;
886                     }
887 #ifdef INET6
888                     /* XXX IPv4 mapped IPv6 addr consideraton */
889                     if (hi->ai_addr->sa_family == AF_INET && mapped_in6 != NULL &&
890                         (memcmp(&mapped_in6->s6_addr[12],
891                                   &((struct sockaddr_in *)hi->ai_addr)->sin_addr,
892                                   sizeof(struct in_addr)) == 0)) {
893                               thishost = hrp;
894                               goto found;
895                     }
896 #endif
897               }
898               hrp = hrp->next;
899           }
900 found:
901           su->su_port = port;
902           /* setup static variables as appropriate */
903           hostname = thishost->hostname;
904           ftpuser = thishost->anonuser;
905 }
906 #endif
907 
908 /*
909  * Helper function for sgetpwnam().
910  */
911 static char *
sgetsave(char * s)912 sgetsave(char *s)
913 {
914           char *new = malloc(strlen(s) + 1);
915 
916           if (new == NULL) {
917                     reply(421, "Ran out of memory.");
918                     dologout(1);
919                     /* NOTREACHED */
920           }
921           strcpy(new, s);
922           return (new);
923 }
924 
925 /*
926  * Save the result of a getpwnam.  Used for USER command, since
927  * the data returned must not be clobbered by any other command
928  * (e.g., globbing).
929  * NB: The data returned by sgetpwnam() will remain valid until
930  * the next call to this function.  Its difference from getpwnam()
931  * is that sgetpwnam() is known to be called from ftpd code only.
932  */
933 static struct passwd *
sgetpwnam(char * name)934 sgetpwnam(char *name)
935 {
936           static struct passwd save;
937           struct passwd *p;
938 
939           if ((p = getpwnam(name)) == NULL)
940                     return (p);
941           if (save.pw_name) {
942                     free(save.pw_name);
943                     free(save.pw_passwd);
944                     free(save.pw_gecos);
945                     free(save.pw_dir);
946                     free(save.pw_shell);
947           }
948           save = *p;
949           save.pw_name = sgetsave(p->pw_name);
950           save.pw_passwd = sgetsave(p->pw_passwd);
951           save.pw_gecos = sgetsave(p->pw_gecos);
952           save.pw_dir = sgetsave(p->pw_dir);
953           save.pw_shell = sgetsave(p->pw_shell);
954           return (&save);
955 }
956 
957 static int login_attempts;    /* number of failed login attempts */
958 static int askpasswd;                   /* had user command, ask for passwd */
959 static char curname[MAXLOGNAME];        /* current USER name */
960 
961 /*
962  * USER command.
963  * Sets global passwd pointer pw if named account exists and is acceptable;
964  * sets askpasswd if a PASS command is expected.  If logged in previously,
965  * need to reset state.  If name is "ftp" or "anonymous", the name is not in
966  * _PATH_FTPUSERS, and ftp account exists, set guest and pw, then just return.
967  * If account doesn't exist, ask for passwd anyway.  Otherwise, check user
968  * requesting login privileges.  Disallow anyone who does not have a standard
969  * shell as returned by getusershell().  Disallow anyone mentioned in the file
970  * _PATH_FTPUSERS to allow people such as root and uucp to be avoided.
971  */
972 void
user(char * name)973 user(char *name)
974 {
975           char *cp, *shell;
976 
977           if (logged_in) {
978                     if (guest) {
979                               reply(530, "Can't change user from guest login.");
980                               return;
981                     } else if (dochroot) {
982                               reply(530, "Can't change user from chroot user.");
983                               return;
984                     }
985                     end_login();
986           }
987 
988           guest = 0;
989 #ifdef VIRTUAL_HOSTING
990           pw = sgetpwnam(thishost->anonuser);
991 #else
992           pw = sgetpwnam("ftp");
993 #endif
994           if (strcmp(name, "ftp") == 0 || strcmp(name, "anonymous") == 0) {
995                     if (checkuser(_PATH_FTPUSERS, "ftp", 0, NULL) ||
996                         checkuser(_PATH_FTPUSERS, "anonymous", 0, NULL))
997                               reply(530, "User %s access denied.", name);
998                     else if (pw != NULL) {
999                               guest = 1;
1000                               askpasswd = 1;
1001                               reply(331,
1002                               "Guest login ok, send your email address as password.");
1003                     } else
1004                               reply(530, "User %s unknown.", name);
1005                     if (!askpasswd && logging)
1006                               syslog(LOG_NOTICE,
1007                                   "ANONYMOUS FTP LOGIN REFUSED FROM %s", remotehost);
1008                     return;
1009           }
1010           if (anon_only != 0) {
1011                     reply(530, "Sorry, only anonymous ftp allowed.");
1012                     return;
1013           }
1014 
1015           if ((pw = sgetpwnam(name))) {
1016                     if ((shell = pw->pw_shell) == NULL || *shell == 0)
1017                               shell = _PATH_BSHELL;
1018                     setusershell();
1019                     while ((cp = getusershell()) != NULL)
1020                               if (strcmp(cp, shell) == 0)
1021                                         break;
1022                     endusershell();
1023 
1024                     if (cp == NULL || checkuser(_PATH_FTPUSERS, name, 1, NULL)) {
1025                               reply(530, "User %s access denied.", name);
1026                               if (logging)
1027                                         syslog(LOG_NOTICE,
1028                                             "FTP LOGIN REFUSED FROM %s, %s",
1029                                             remotehost, name);
1030                               pw = NULL;
1031                               return;
1032                     }
1033           }
1034           if (logging)
1035                     strncpy(curname, name, sizeof(curname)-1);
1036 
1037           pwok = 1;
1038           reply(331, "Password required for %s.", name);
1039           askpasswd = 1;
1040           /*
1041            * Delay before reading passwd after first failed
1042            * attempt to slow down passwd-guessing programs.
1043            */
1044           if (login_attempts)
1045                     sleep(login_attempts);
1046 }
1047 
1048 /*
1049  * Check if a user is in the file "fname",
1050  * return a pointer to a malloc'd string with the rest
1051  * of the matching line in "residue" if not NULL.
1052  */
1053 static int
checkuser(char * fname,char * name,int pwset,char ** residue)1054 checkuser(char *fname, char *name, int pwset, char **residue)
1055 {
1056           FILE *fd;
1057           int found = 0;
1058           size_t len;
1059           char *line, *mp, *p;
1060 
1061           if ((fd = fopen(fname, "r")) != NULL) {
1062                     while (!found && (line = fgetln(fd, &len)) != NULL) {
1063                               /* skip comments */
1064                               if (line[0] == '#')
1065                                         continue;
1066                               if (line[len - 1] == '\n') {
1067                                         line[len - 1] = '\0';
1068                                         mp = NULL;
1069                               } else {
1070                                         if ((mp = malloc(len + 1)) == NULL)
1071                                                   fatalerror("Ran out of memory.");
1072                                         memcpy(mp, line, len);
1073                                         mp[len] = '\0';
1074                                         line = mp;
1075                               }
1076                               /* avoid possible leading and trailing whitespace */
1077                               p = strtok(line, " \t");
1078                               /* skip empty lines */
1079                               if (p == NULL)
1080                                         goto nextline;
1081                               /*
1082                                * if first chr is '@', check group membership
1083                                */
1084                               if (p[0] == '@') {
1085                                         int i = 0;
1086                                         struct group *grp;
1087 
1088                                         if (p[1] == '\0') /* single @ matches anyone */
1089                                                   found = 1;
1090                                         else {
1091                                                   if ((grp = getgrnam(p+1)) == NULL)
1092                                                             goto nextline;
1093                                                   /*
1094                                                    * Check user's default group
1095                                                    */
1096                                                   if (pwset && grp->gr_gid == pw->pw_gid)
1097                                                             found = 1;
1098                                                   /*
1099                                                    * Check supplementary groups
1100                                                    */
1101                                                   while (!found && grp->gr_mem[i])
1102                                                             found = strcmp(name,
1103                                                                       grp->gr_mem[i++])
1104                                                                       == 0;
1105                                         }
1106                               }
1107                               /*
1108                                * Otherwise, just check for username match
1109                                */
1110                               else
1111                                         found = strcmp(p, name) == 0;
1112                               /*
1113                                * Save the rest of line to "residue" if matched
1114                                */
1115                               if (found && residue) {
1116                                         if ((p = strtok(NULL, "")) != NULL)
1117                                                   p += strspn(p, " \t");
1118                                         if (p && *p) {
1119                                                   if ((*residue = strdup(p)) == NULL)
1120                                                             fatalerror("Ran out of memory.");
1121                                         } else
1122                                                   *residue = NULL;
1123                               }
1124 nextline:
1125                               if (mp)
1126                                         free(mp);
1127                     }
1128                     fclose(fd);
1129           }
1130           return (found);
1131 }
1132 
1133 /*
1134  * Terminate login as previous user, if any, resetting state;
1135  * used when USER command is given or login fails.
1136  */
1137 static void
end_login(void)1138 end_login(void)
1139 {
1140 #ifdef USE_PAM
1141           int e;
1142 #endif
1143 
1144           seteuid(0);
1145           if (logged_in && dowtmpx)
1146                     ftpd_logwtmpx(ttyline, "", NULL);
1147           pw = NULL;
1148 #ifdef    LOGIN_CAP
1149           /* XXX Missing LOGIN_SETMAC */
1150           setusercontext(NULL, getpwuid(0), 0,
1151                            LOGIN_SETPRIORITY|LOGIN_SETRESOURCES|LOGIN_SETUMASK);
1152 #endif
1153 #ifdef USE_PAM
1154           if (pamh) {
1155                     if ((e = pam_setcred(pamh, PAM_DELETE_CRED)) != PAM_SUCCESS)
1156                               syslog(LOG_ERR, "pam_setcred: %s", pam_strerror(pamh, e));
1157                     if ((e = pam_close_session(pamh,0)) != PAM_SUCCESS)
1158                               syslog(LOG_ERR, "pam_close_session: %s", pam_strerror(pamh, e));
1159                     if ((e = pam_end(pamh, e)) != PAM_SUCCESS)
1160                               syslog(LOG_ERR, "pam_end: %s", pam_strerror(pamh, e));
1161                     pamh = NULL;
1162           }
1163 #endif
1164           logged_in = 0;
1165           guest = 0;
1166           dochroot = 0;
1167 }
1168 
1169 #ifdef USE_PAM
1170 
1171 /*
1172  * the following code is stolen from imap-uw PAM authentication module and
1173  * login.c
1174  */
1175 #define COPY_STRING(s) (s ? strdup(s) : NULL)
1176 
1177 struct cred_t {
1178           const char *uname;            /* user name */
1179           const char *pass;             /* password */
1180 };
1181 typedef struct cred_t cred_t;
1182 
1183 static int
auth_conv(int num_msg,const struct pam_message ** msg,struct pam_response ** resp,void * appdata)1184 auth_conv(int num_msg, const struct pam_message **msg,
1185             struct pam_response **resp, void *appdata)
1186 {
1187           int i;
1188           cred_t *cred = (cred_t *) appdata;
1189           struct pam_response *reply;
1190 
1191           reply = calloc(num_msg, sizeof *reply);
1192           if (reply == NULL)
1193                     return PAM_BUF_ERR;
1194 
1195           for (i = 0; i < num_msg; i++) {
1196                     switch (msg[i]->msg_style) {
1197                     case PAM_PROMPT_ECHO_ON:      /* assume want user name */
1198                               reply[i].resp_retcode = PAM_SUCCESS;
1199                               reply[i].resp = COPY_STRING(cred->uname);
1200                               /* PAM frees resp. */
1201                               break;
1202                     case PAM_PROMPT_ECHO_OFF:     /* assume want password */
1203                               reply[i].resp_retcode = PAM_SUCCESS;
1204                               reply[i].resp = COPY_STRING(cred->pass);
1205                               /* PAM frees resp. */
1206                               break;
1207                     case PAM_TEXT_INFO:
1208                     case PAM_ERROR_MSG:
1209                               reply[i].resp_retcode = PAM_SUCCESS;
1210                               reply[i].resp = NULL;
1211                               break;
1212                     default:                      /* unknown message style */
1213                               free(reply);
1214                               return PAM_CONV_ERR;
1215                     }
1216           }
1217 
1218           *resp = reply;
1219           return PAM_SUCCESS;
1220 }
1221 
1222 /*
1223  * Attempt to authenticate the user using PAM.  Returns 0 if the user is
1224  * authenticated, or 1 if not authenticated.  If some sort of PAM system
1225  * error occurs (e.g., the "/etc/pam.conf" file is missing) then this
1226  * function returns -1.  This can be used as an indication that we should
1227  * fall back to a different authentication mechanism.
1228  */
1229 static int
auth_pam(struct passwd ** ppw,const char * pass)1230 auth_pam(struct passwd **ppw, const char *pass)
1231 {
1232           const char *tmpl_user;
1233           const void *item;
1234           int rval;
1235           int e;
1236           cred_t auth_cred = { (*ppw)->pw_name, pass };
1237           struct pam_conv conv = { &auth_conv, &auth_cred };
1238 
1239           e = pam_start("ftpd", (*ppw)->pw_name, &conv, &pamh);
1240           if (e != PAM_SUCCESS) {
1241                     /*
1242                      * In OpenPAM, it's OK to pass NULL to pam_strerror()
1243                      * if context creation has failed in the first place.
1244                      */
1245                     syslog(LOG_ERR, "pam_start: %s", pam_strerror(NULL, e));
1246                     return -1;
1247           }
1248 
1249           e = pam_set_item(pamh, PAM_RHOST, remotehost);
1250           if (e != PAM_SUCCESS) {
1251                     syslog(LOG_ERR, "pam_set_item(PAM_RHOST): %s",
1252                               pam_strerror(pamh, e));
1253                     if ((e = pam_end(pamh, e)) != PAM_SUCCESS) {
1254                               syslog(LOG_ERR, "pam_end: %s", pam_strerror(pamh, e));
1255                     }
1256                     pamh = NULL;
1257                     return -1;
1258           }
1259 
1260           e = pam_authenticate(pamh, 0);
1261           switch (e) {
1262           case PAM_SUCCESS:
1263                     /*
1264                      * With PAM we support the concept of a "template"
1265                      * user.  The user enters a login name which is
1266                      * authenticated by PAM, usually via a remote service
1267                      * such as RADIUS or TACACS+.  If authentication
1268                      * succeeds, a different but related "template" name
1269                      * is used for setting the credentials, shell, and
1270                      * home directory.  The name the user enters need only
1271                      * exist on the remote authentication server, but the
1272                      * template name must be present in the local password
1273                      * database.
1274                      *
1275                      * This is supported by two various mechanisms in the
1276                      * individual modules.  However, from the application's
1277                      * point of view, the template user is always passed
1278                      * back as a changed value of the PAM_USER item.
1279                      */
1280                     if ((e = pam_get_item(pamh, PAM_USER, &item)) ==
1281                         PAM_SUCCESS) {
1282                               tmpl_user = (const char *) item;
1283                               if (strcmp((*ppw)->pw_name, tmpl_user) != 0)
1284                                         *ppw = getpwnam(tmpl_user);
1285                     } else
1286                               syslog(LOG_ERR, "Couldn't get PAM_USER: %s",
1287                                   pam_strerror(pamh, e));
1288                     rval = 0;
1289                     break;
1290 
1291           case PAM_AUTH_ERR:
1292           case PAM_USER_UNKNOWN:
1293           case PAM_MAXTRIES:
1294                     rval = 1;
1295                     break;
1296 
1297           default:
1298                     syslog(LOG_ERR, "pam_authenticate: %s", pam_strerror(pamh, e));
1299                     rval = -1;
1300                     break;
1301           }
1302 
1303           if (rval == 0) {
1304                     e = pam_acct_mgmt(pamh, 0);
1305                     if (e != PAM_SUCCESS) {
1306                               syslog(LOG_ERR, "pam_acct_mgmt: %s",
1307                                                             pam_strerror(pamh, e));
1308                               rval = 1;
1309                     }
1310           }
1311 
1312           if (rval != 0) {
1313                     if ((e = pam_end(pamh, e)) != PAM_SUCCESS) {
1314                               syslog(LOG_ERR, "pam_end: %s", pam_strerror(pamh, e));
1315                     }
1316                     pamh = NULL;
1317           }
1318           return rval;
1319 }
1320 
1321 #endif /* USE_PAM */
1322 
1323 void
pass(char * passwd)1324 pass(char *passwd)
1325 {
1326           int rval;
1327           FILE *fd;
1328 #ifdef    LOGIN_CAP
1329           login_cap_t *lc = NULL;
1330 #endif
1331 #ifdef USE_PAM
1332           int e;
1333 #endif
1334           char *residue = NULL;
1335           char *xpasswd;
1336 
1337           if (logged_in || askpasswd == 0) {
1338                     reply(503, "Login with USER first.");
1339                     return;
1340           }
1341           askpasswd = 0;
1342           if (!guest) {                 /* "ftp" is only account allowed no password */
1343                     if (pw == NULL) {
1344                               rval = 1; /* failure below */
1345                               goto skip;
1346                     }
1347 #ifdef USE_PAM
1348                     rval = auth_pam(&pw, passwd);
1349                     if (rval >= 0)
1350                               goto skip;
1351 #endif
1352                     if (pwok) {
1353                               xpasswd = crypt(passwd, pw->pw_passwd);
1354                               if (passwd[0] == '\0' && pw->pw_passwd[0] != '\0')
1355                                         xpasswd = ":";
1356                     } else {
1357                               rval = 1;
1358                               goto skip;
1359                     }
1360                     rval = strcmp(pw->pw_passwd, xpasswd);
1361                     if (pw->pw_expire && time(NULL) >= pw->pw_expire)
1362                               rval = 1; /* failure */
1363 skip:
1364                     /*
1365                      * If rval == 1, the user failed the authentication check
1366                      * above.  If rval == 0, either PAM or local authentication
1367                      * succeeded.
1368                      */
1369                     if (rval) {
1370                               reply(530, "Login incorrect.");
1371                               if (logging) {
1372                                         syslog(LOG_NOTICE,
1373                                             "FTP LOGIN FAILED FROM %s",
1374                                             remotehost);
1375                                         syslog(LOG_AUTHPRIV | LOG_NOTICE,
1376                                             "FTP LOGIN FAILED FROM %s, %s",
1377                                             remotehost, curname);
1378                               }
1379                               pw = NULL;
1380                               if (login_attempts++ >= 5) {
1381                                         syslog(LOG_NOTICE,
1382                                             "repeated login failures from %s",
1383                                             remotehost);
1384                                         exit(0);
1385                               }
1386                               return;
1387                     }
1388           }
1389           login_attempts = 0;           /* this time successful */
1390           if (setegid(pw->pw_gid) < 0) {
1391                     reply(550, "Can't set gid.");
1392                     return;
1393           }
1394           /* May be overridden by login.conf */
1395           umask(defumask);
1396 #ifdef    LOGIN_CAP
1397           if ((lc = login_getpwclass(pw)) != NULL) {
1398                     char      remote_ip[NI_MAXHOST];
1399 
1400                     if (getnameinfo((struct sockaddr *)&his_addr, his_addr.su_len,
1401                               remote_ip, sizeof(remote_ip) - 1, NULL, 0,
1402                               NI_NUMERICHOST))
1403                                         *remote_ip = 0;
1404                     remote_ip[sizeof(remote_ip) - 1] = 0;
1405                     if (!auth_hostok(lc, remotehost, remote_ip)) {
1406                               syslog(LOG_INFO|LOG_AUTH,
1407                                   "FTP LOGIN FAILED (HOST) as %s: permission denied.",
1408                                   pw->pw_name);
1409                               reply(530, "Permission denied.");
1410                               pw = NULL;
1411                               return;
1412                     }
1413                     if (!auth_timeok(lc, time(NULL))) {
1414                               reply(530, "Login not available right now.");
1415                               pw = NULL;
1416                               return;
1417                     }
1418           }
1419           /* XXX Missing LOGIN_SETMAC */
1420           setusercontext(lc, pw, 0,
1421                     LOGIN_SETLOGIN|LOGIN_SETGROUP|LOGIN_SETPRIORITY|
1422                     LOGIN_SETRESOURCES|LOGIN_SETUMASK);
1423 #else
1424           setlogin(pw->pw_name);
1425           initgroups(pw->pw_name, pw->pw_gid);
1426 #endif
1427 
1428 #ifdef USE_PAM
1429           if (pamh) {
1430                     if ((e = pam_open_session(pamh, 0)) != PAM_SUCCESS) {
1431                               syslog(LOG_ERR, "pam_open_session: %s", pam_strerror(pamh, e));
1432                     } else if ((e = pam_setcred(pamh, PAM_ESTABLISH_CRED)) != PAM_SUCCESS) {
1433                               syslog(LOG_ERR, "pam_setcred: %s", pam_strerror(pamh, e));
1434                     }
1435           }
1436 #endif
1437 
1438           /* open wtmpx before chroot */
1439           if (dowtmpx)
1440                     ftpd_logwtmpx(ttyline, pw->pw_name,
1441                         (struct sockaddr *)&his_addr);
1442           logged_in = 1;
1443 
1444           if (guest && stats && statfd < 0)
1445 #ifdef VIRTUAL_HOSTING
1446                     statfd = open(thishost->statfile, O_WRONLY|O_APPEND);
1447 #else
1448                     statfd = open(_PATH_FTPDSTATFILE, O_WRONLY|O_APPEND);
1449 #endif
1450                     if (statfd < 0)
1451                               stats = 0;
1452 
1453           dochroot =
1454                     checkuser(_PATH_FTPCHROOT, pw->pw_name, 1, &residue)
1455 #ifdef    LOGIN_CAP /* Allow login.conf configuration as well */
1456                     || login_getcapbool(lc, "ftp-chroot", 0)
1457 #endif
1458           ;
1459           chrootdir = NULL;
1460           /*
1461            * For a chrooted local user,
1462            * a) see whether ftpchroot(5) specifies a chroot directory,
1463            * b) extract the directory pathname from the line,
1464            * c) expand it to the absolute pathname if necessary.
1465            */
1466           if (dochroot && residue &&
1467               (chrootdir = strtok(residue, " \t")) != NULL) {
1468                     if (chrootdir[0] != '/')
1469                               asprintf(&chrootdir, "%s/%s", pw->pw_dir, chrootdir);
1470                     else
1471                               chrootdir = strdup(chrootdir); /* make it permanent */
1472                     if (chrootdir == NULL)
1473                               fatalerror("Ran out of memory.");
1474           }
1475           if (guest || dochroot) {
1476                     /*
1477                      * If no chroot directory set yet, use the login directory.
1478                      * Copy it so it can be modified while pw->pw_dir stays intact.
1479                      */
1480                     if (chrootdir == NULL &&
1481                         (chrootdir = strdup(pw->pw_dir)) == NULL)
1482                               fatalerror("Ran out of memory.");
1483                     /*
1484                      * Check for the "/chroot/./home" syntax,
1485                      * separate the chroot and home directory pathnames.
1486                      */
1487                     if ((homedir = strstr(chrootdir, "/./")) != NULL) {
1488                               *(homedir++) = '\0';          /* wipe '/' */
1489                               homedir++;                    /* skip '.' */
1490                     } else {
1491                               /*
1492                                * We MUST do a chdir() after the chroot. Otherwise
1493                                * the old current directory will be accessible as "."
1494                                * outside the new root!
1495                                */
1496                               homedir = "/";
1497                     }
1498                     /*
1499                      * Finally, do chroot()
1500                      */
1501                     if (chroot(chrootdir) < 0) {
1502                               reply(550, "Can't change root.");
1503                               goto bad;
1504                     }
1505           } else    /* real user w/o chroot */
1506                     homedir = pw->pw_dir;
1507           /*
1508            * Set euid *before* doing chdir() so
1509            * a) the user won't be carried to a directory that he couldn't reach
1510            *    on his own due to no permission to upper path components,
1511            * b) NFS mounted homedirs w/restrictive permissions will be accessible
1512            *    (uid 0 has no root power over NFS if not mapped explicitly.)
1513            */
1514           if (seteuid(pw->pw_uid) < 0) {
1515                     if (guest || dochroot) {
1516                               fatalerror("Can't set uid.");
1517                     } else {
1518                               reply(550, "Can't set uid.");
1519                               goto bad;
1520                     }
1521           }
1522           /*
1523            * Do not allow the session to live if we're chroot()'ed and chdir()
1524            * fails. Otherwise the chroot jail can be escaped.
1525            */
1526           if (chdir(homedir) < 0) {
1527                     if (guest || dochroot) {
1528                               fatalerror("Can't change to base directory.");
1529                     } else {
1530                               if (chdir("/") < 0) {
1531                                         reply(550, "Root is inaccessible.");
1532                                         goto bad;
1533                               }
1534                               lreply(230, "No directory! Logging in with home=/.");
1535                     }
1536           }
1537 
1538           /*
1539            * Display a login message, if it exists.
1540            * N.B. reply(230,) must follow the message.
1541            */
1542 #ifdef VIRTUAL_HOSTING
1543           fd = fopen(thishost->loginmsg, "r");
1544 #else
1545           fd = fopen(_PATH_FTPLOGINMESG, "r");
1546 #endif
1547           if (fd != NULL) {
1548                     char *cp, line[LINE_MAX];
1549 
1550                     while (fgets(line, sizeof(line), fd) != NULL) {
1551                               if ((cp = strchr(line, '\n')) != NULL)
1552                                         *cp = '\0';
1553                               lreply(230, "%s", line);
1554                     }
1555                     fflush(stdout);
1556                     fclose(fd);
1557           }
1558           if (guest) {
1559                     if (ident != NULL)
1560                               free(ident);
1561                     ident = strdup(passwd);
1562                     if (ident == NULL)
1563                               fatalerror("Ran out of memory.");
1564 
1565                     reply(230, "Guest login ok, access restrictions apply.");
1566 #ifdef SETPROCTITLE
1567 #ifdef VIRTUAL_HOSTING
1568                     if (thishost != firsthost)
1569                               snprintf(proctitle, sizeof(proctitle),
1570                                          "%s: anonymous(%s)/%s", remotehost, hostname,
1571                                          passwd);
1572                     else
1573 #endif
1574                               snprintf(proctitle, sizeof(proctitle),
1575                                          "%s: anonymous/%s", remotehost, passwd);
1576                     setproctitle("%s", proctitle);
1577 #endif /* SETPROCTITLE */
1578                     if (logging)
1579                               syslog(LOG_INFO, "ANONYMOUS FTP LOGIN FROM %s, %s",
1580                                   remotehost, passwd);
1581           } else {
1582                     if (dochroot)
1583                               reply(230, "User %s logged in, "
1584                                            "access restrictions apply.", pw->pw_name);
1585                     else
1586                               reply(230, "User %s logged in.", pw->pw_name);
1587 
1588 #ifdef SETPROCTITLE
1589                     snprintf(proctitle, sizeof(proctitle),
1590                                "%s: user/%s", remotehost, pw->pw_name);
1591                     setproctitle("%s", proctitle);
1592 #endif /* SETPROCTITLE */
1593                     if (logging)
1594                               syslog(LOG_INFO, "FTP LOGIN FROM %s as %s",
1595                                   remotehost, pw->pw_name);
1596           }
1597           if (logging && (guest || dochroot))
1598                     syslog(LOG_INFO, "session root changed to %s", chrootdir);
1599 #ifdef    LOGIN_CAP
1600           login_close(lc);
1601 #endif
1602           if (residue)
1603                     free(residue);
1604           return;
1605 bad:
1606           /* Forget all about it... */
1607 #ifdef    LOGIN_CAP
1608           login_close(lc);
1609 #endif
1610           if (residue)
1611                     free(residue);
1612           end_login();
1613 }
1614 
1615 void
retrieve(char * cmd,char * name)1616 retrieve(char *cmd, char *name)
1617 {
1618           FILE *fin, *dout;
1619           struct stat st;
1620           int (*closefunc)(FILE *);
1621           time_t start;
1622 
1623           if (cmd == NULL) {
1624                     fin = fopen(name, "r"), closefunc = fclose;
1625                     st.st_size = 0;
1626           } else {
1627                     char line[BUFSIZ];
1628 
1629                     snprintf(line, sizeof(line), cmd, name), name = line;
1630                     fin = ftpd_popen(line, "r"), closefunc = ftpd_pclose;
1631                     st.st_size = -1;
1632                     st.st_blksize = BUFSIZ;
1633           }
1634           if (fin == NULL) {
1635                     if (errno != 0) {
1636                               perror_reply(550, name);
1637                               if (cmd == NULL) {
1638                                         LOGCMD("get", name);
1639                               }
1640                     }
1641                     return;
1642           }
1643           byte_count = -1;
1644           if (cmd == NULL) {
1645                     if (fstat(fileno(fin), &st) < 0) {
1646                               perror_reply(550, name);
1647                               goto done;
1648                     }
1649                     if (!S_ISREG(st.st_mode)) {
1650                               /*
1651                                * Never sending a raw directory is a workaround
1652                                * for buggy clients that will attempt to RETR
1653                                * a directory before listing it, e.g., Mozilla.
1654                                * Preventing a guest from getting irregular files
1655                                * is a simple security measure.
1656                                */
1657                               if (S_ISDIR(st.st_mode) || guest) {
1658                                         reply(550, "%s: not a plain file.", name);
1659                                         goto done;
1660                               }
1661                               st.st_size = -1;
1662                               /* st.st_blksize is set for all descriptor types */
1663                     }
1664           }
1665           if (restart_point) {
1666                     if (type == TYPE_A) {
1667                               off_t i, n;
1668                               int c;
1669 
1670                               n = restart_point;
1671                               i = 0;
1672                               while (i++ < n) {
1673                                         if ((c=getc(fin)) == EOF) {
1674                                                   perror_reply(550, name);
1675                                                   goto done;
1676                                         }
1677                                         if (c == '\n')
1678                                                   i++;
1679                               }
1680                     } else if (lseek(fileno(fin), restart_point, L_SET) < 0) {
1681                               perror_reply(550, name);
1682                               goto done;
1683                     }
1684           }
1685           dout = dataconn(name, st.st_size, "w");
1686           if (dout == NULL)
1687                     goto done;
1688           time(&start);
1689           send_data(fin, dout, st.st_blksize, st.st_size,
1690                       restart_point == 0 && cmd == NULL && S_ISREG(st.st_mode));
1691           if (cmd == NULL && guest && stats && byte_count > 0)
1692                     logxfer(name, byte_count, start);
1693           fclose(dout);
1694           data = -1;
1695           pdata = -1;
1696 done:
1697           if (cmd == NULL)
1698                     LOGBYTES("get", name, byte_count);
1699           (*closefunc)(fin);
1700 }
1701 
1702 void
store(char * name,char * mode,int unique)1703 store(char *name, char *mode, int unique)
1704 {
1705           int fd;
1706           FILE *fout, *din;
1707           int (*closefunc)(FILE *);
1708 
1709           if (*mode == 'a') {           /* APPE */
1710                     if (unique) {
1711                               /* Programming error */
1712                               syslog(LOG_ERR, "Internal: unique flag to APPE");
1713                               unique = 0;
1714                     }
1715                     if (guest && noguestmod) {
1716                               reply(550, "Appending to existing file denied.");
1717                               goto err;
1718                     }
1719                     restart_point = 0;  /* not affected by preceding REST */
1720           }
1721           if (unique)                             /* STOU overrides REST */
1722                     restart_point = 0;
1723           if (guest && noguestmod) {
1724                     if (restart_point) {          /* guest STOR w/REST */
1725                               reply(550, "Modifying existing file denied.");
1726                               goto err;
1727                     } else                        /* treat guest STOR as STOU */
1728                               unique = 1;
1729           }
1730 
1731           if (restart_point)
1732                     mode = "r+";        /* so ASCII manual seek can work */
1733           if (unique) {
1734                     if ((fd = guniquefd(name, &name)) < 0)
1735                               goto err;
1736                     fout = fdopen(fd, mode);
1737           } else
1738                     fout = fopen(name, mode);
1739           closefunc = fclose;
1740           if (fout == NULL) {
1741                     perror_reply(553, name);
1742                     goto err;
1743           }
1744           byte_count = -1;
1745           if (restart_point) {
1746                     if (type == TYPE_A) {
1747                               off_t i, n;
1748                               int c;
1749 
1750                               n = restart_point;
1751                               i = 0;
1752                               while (i++ < n) {
1753                                         if ((c=getc(fout)) == EOF) {
1754                                                   perror_reply(550, name);
1755                                                   goto done;
1756                                         }
1757                                         if (c == '\n')
1758                                                   i++;
1759                               }
1760                               /*
1761                                * We must do this seek to "current" position
1762                                * because we are changing from reading to
1763                                * writing.
1764                                */
1765                               if (fseeko(fout, 0, SEEK_CUR) < 0) {
1766                                         perror_reply(550, name);
1767                                         goto done;
1768                               }
1769                     } else if (lseek(fileno(fout), restart_point, L_SET) < 0) {
1770                               perror_reply(550, name);
1771                               goto done;
1772                     }
1773           }
1774           din = dataconn(name, -1, "r");
1775           if (din == NULL)
1776                     goto done;
1777           if (receive_data(din, fout) == 0) {
1778                     if (unique)
1779                               reply(226, "Transfer complete (unique file name:%s).",
1780                                   name);
1781                     else
1782                               reply(226, "Transfer complete.");
1783           }
1784           fclose(din);
1785           data = -1;
1786           pdata = -1;
1787 done:
1788           LOGBYTES(*mode == 'a' ? "append" : "put", name, byte_count);
1789           (*closefunc)(fout);
1790           return;
1791 err:
1792           LOGCMD(*mode == 'a' ? "append" : "put" , name);
1793           return;
1794 }
1795 
1796 static FILE *
getdatasock(char * mode)1797 getdatasock(char *mode)
1798 {
1799           int on = 1, s, t, tries;
1800 
1801           if (data >= 0)
1802                     return (fdopen(data, mode));
1803 
1804           s = socket(data_dest.su_family, SOCK_STREAM, 0);
1805           if (s < 0)
1806                     goto bad;
1807           if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
1808                     syslog(LOG_WARNING, "data setsockopt (SO_REUSEADDR): %m");
1809           /* anchor socket to avoid multi-homing problems */
1810           data_source = ctrl_addr;
1811           data_source.su_port = htons(dataport);
1812           seteuid(0);
1813           for (tries = 1; ; tries++) {
1814                     /*
1815                      * We should loop here since it's possible that
1816                      * another ftpd instance has passed this point and is
1817                      * trying to open a data connection in active mode now.
1818                      * Until the other connection is opened, we'll be getting
1819                      * EADDRINUSE because no SOCK_STREAM sockets in the system
1820                      * can share both local and remote addresses, localIP:20
1821                      * and *:* in this case.
1822                      */
1823                     if (bind(s, (struct sockaddr *)&data_source,
1824                         data_source.su_len) >= 0)
1825                               break;
1826                     if (errno != EADDRINUSE || tries > 10)
1827                               goto bad;
1828                     sleep(tries);
1829           }
1830           seteuid(pw->pw_uid);
1831 #ifdef IP_TOS
1832           if (data_source.su_family == AF_INET)
1833       {
1834           on = IPTOS_THROUGHPUT;
1835           if (setsockopt(s, IPPROTO_IP, IP_TOS, &on, sizeof(int)) < 0)
1836                     syslog(LOG_WARNING, "data setsockopt (IP_TOS): %m");
1837       }
1838 #endif
1839 #ifdef TCP_NOPUSH
1840           /*
1841            * Turn off push flag to keep sender TCP from sending short packets
1842            * at the boundaries of each write().
1843            */
1844           on = 1;
1845           if (setsockopt(s, IPPROTO_TCP, TCP_NOPUSH, &on, sizeof on) < 0)
1846                     syslog(LOG_WARNING, "data setsockopt (TCP_NOPUSH): %m");
1847 #endif
1848           return (fdopen(s, mode));
1849 bad:
1850           /* Return the real value of errno (close may change it) */
1851           t = errno;
1852           seteuid(pw->pw_uid);
1853           close(s);
1854           errno = t;
1855           return (NULL);
1856 }
1857 
1858 static FILE *
dataconn(char * name,off_t size,char * mode)1859 dataconn(char *name, off_t size, char *mode)
1860 {
1861           char sizebuf[32];
1862           FILE *file;
1863           int retry = 0, tos, conerrno;
1864 
1865           file_size = size;
1866           byte_count = 0;
1867           if (size != -1)
1868                     snprintf(sizebuf, sizeof(sizebuf),
1869                                         " (%jd bytes)", (intmax_t)size);
1870           else
1871                     *sizebuf = '\0';
1872           if (pdata >= 0) {
1873                     union sockunion from;
1874                     socklen_t fromlen = ctrl_addr.su_len;
1875                     int flags, s;
1876                     struct timeval timeout;
1877                     fd_set set;
1878 
1879                     FD_ZERO(&set);
1880                     FD_SET(pdata, &set);
1881 
1882                     timeout.tv_usec = 0;
1883                     timeout.tv_sec = 120;
1884 
1885                     /*
1886                      * Granted a socket is in the blocking I/O mode,
1887                      * accept() will block after a successful select()
1888                      * if the selected connection dies in between.
1889                      * Therefore set the non-blocking I/O flag here.
1890                      */
1891                     if ((flags = fcntl(pdata, F_GETFL, 0)) == -1 ||
1892                         fcntl(pdata, F_SETFL, flags | O_NONBLOCK) == -1)
1893                               goto pdata_err;
1894                     if (select(pdata+1, &set, NULL, NULL, &timeout) <= 0 ||
1895                         (s = accept(pdata, (struct sockaddr *) &from, &fromlen)) < 0)
1896                               goto pdata_err;
1897                     close(pdata);
1898                     pdata = s;
1899                     /*
1900                      * Unset the inherited non-blocking I/O flag
1901                      * on the child socket so stdio can work on it.
1902                      */
1903                     if ((flags = fcntl(pdata, F_GETFL, 0)) == -1 ||
1904                         fcntl(pdata, F_SETFL, flags & ~O_NONBLOCK) == -1)
1905                               goto pdata_err;
1906 #ifdef IP_TOS
1907                     if (from.su_family == AF_INET)
1908                 {
1909                     tos = IPTOS_THROUGHPUT;
1910                     if (setsockopt(s, IPPROTO_IP, IP_TOS, &tos, sizeof(int)) < 0)
1911                               syslog(LOG_WARNING, "pdata setsockopt (IP_TOS): %m");
1912                 }
1913 #endif
1914                     reply(150, "Opening %s mode data connection for '%s'%s.",
1915                          type == TYPE_A ? "ASCII" : "BINARY", name, sizebuf);
1916                     return (fdopen(pdata, mode));
1917 pdata_err:
1918                     reply(425, "Can't open data connection.");
1919                     close(pdata);
1920                     pdata = -1;
1921                     return (NULL);
1922           }
1923           if (data >= 0) {
1924                     reply(125, "Using existing data connection for '%s'%s.",
1925                         name, sizebuf);
1926                     usedefault = 1;
1927                     return (fdopen(data, mode));
1928           }
1929           if (usedefault)
1930                     data_dest = his_addr;
1931           usedefault = 1;
1932           do {
1933                     file = getdatasock(mode);
1934                     if (file == NULL) {
1935                               char hostbuf[NI_MAXHOST], portbuf[NI_MAXSERV];
1936 
1937                               if (getnameinfo((struct sockaddr *)&data_source,
1938                                         data_source.su_len,
1939                                         hostbuf, sizeof(hostbuf) - 1,
1940                                         portbuf, sizeof(portbuf) - 1,
1941                                         NI_NUMERICHOST|NI_NUMERICSERV))
1942                                                   *hostbuf = *portbuf = 0;
1943                               hostbuf[sizeof(hostbuf) - 1] = 0;
1944                               portbuf[sizeof(portbuf) - 1] = 0;
1945                               reply(425, "Can't create data socket (%s,%s): %s.",
1946                                         hostbuf, portbuf, strerror(errno));
1947                               return (NULL);
1948                     }
1949                     data = fileno(file);
1950                     conerrno = 0;
1951                     if (connect(data, (struct sockaddr *)&data_dest,
1952                         data_dest.su_len) == 0)
1953                               break;
1954                     conerrno = errno;
1955                     fclose(file);
1956                     data = -1;
1957                     if (conerrno == EADDRINUSE) {
1958                               sleep(swaitint);
1959                               retry += swaitint;
1960                     } else {
1961                               break;
1962                     }
1963           } while (retry <= swaitmax);
1964           if (conerrno != 0) {
1965                     reply(425, "Can't build data connection: %s.",
1966                                  strerror(conerrno));
1967                     return (NULL);
1968           }
1969           reply(150, "Opening %s mode data connection for '%s'%s.",
1970                type == TYPE_A ? "ASCII" : "BINARY", name, sizebuf);
1971           return (file);
1972 }
1973 
1974 /*
1975  * A helper macro to avoid code duplication
1976  * in send_data() and receive_data().
1977  *
1978  * XXX We have to block SIGURG during putc() because BSD stdio
1979  * is unable to restart interrupted write operations and hence
1980  * the entire buffer contents will be lost as soon as a write()
1981  * call indicates EINTR to stdio.
1982  */
1983 #define FTPD_PUTC(ch, file, label)                                              \
1984           do {                                                                            \
1985                     int ret;                                                    \
1986                                                                                           \
1987                     do {                                                                  \
1988                               START_UNSAFE;                                               \
1989                               ret = putc((ch), (file));                         \
1990                               END_UNSAFE;                                                 \
1991                               CHECKOOB(return (-1))                                       \
1992                               else if (ferror(file))                                      \
1993                                         goto label;                                       \
1994                               clearerr(file);                                             \
1995                     } while (ret == EOF);                                                 \
1996           } while (0)
1997 
1998 /*
1999  * Tranfer the contents of "instr" to "outstr" peer using the appropriate
2000  * encapsulation of the data subject to Mode, Structure, and Type.
2001  *
2002  * NB: Form isn't handled.
2003  */
2004 static int
send_data(FILE * instr,FILE * outstr,size_t blksize,off_t filesize,int isreg)2005 send_data(FILE *instr, FILE *outstr, size_t blksize, off_t filesize, int isreg)
2006 {
2007           int c, cp, filefd, netfd;
2008           char *buf;
2009 
2010           STARTXFER;
2011 
2012           switch (type) {
2013 
2014           case TYPE_A:
2015                     cp = EOF;
2016                     for (;;) {
2017                               c = getc(instr);
2018                               CHECKOOB(return (-1))
2019                               else if (c == EOF && ferror(instr))
2020                                         goto file_err;
2021                               if (c == EOF) {
2022                                         if (ferror(instr)) {          /* resume after OOB */
2023                                                   clearerr(instr);
2024                                                   continue;
2025                                         }
2026                                         if (feof(instr))    /* EOF */
2027                                                   break;
2028                                         syslog(LOG_ERR, "Internal: impossible condition"
2029                                                             " on file after getc()");
2030                                         goto file_err;
2031                               }
2032                               if (c == '\n' && cp != '\r') {
2033                                         FTPD_PUTC('\r', outstr, data_err);
2034                                         byte_count++;
2035                               }
2036                               FTPD_PUTC(c, outstr, data_err);
2037                               byte_count++;
2038                               cp = c;
2039                     }
2040 #ifdef notyet       /* BSD stdio isn't ready for that */
2041                     while (fflush(outstr) == EOF) {
2042                               CHECKOOB(return (-1))
2043                               else
2044                                         goto data_err;
2045                               clearerr(outstr);
2046                     }
2047                     ENDXFER;
2048 #else
2049                     ENDXFER;
2050                     if (fflush(outstr) == EOF)
2051                               goto data_err;
2052 #endif
2053                     reply(226, "Transfer complete.");
2054                     return (0);
2055 
2056           case TYPE_I:
2057           case TYPE_L:
2058                     /*
2059                      * isreg is only set if we are not doing restart and we
2060                      * are sending a regular file
2061                      */
2062                     netfd = fileno(outstr);
2063                     filefd = fileno(instr);
2064 
2065                     if (isreg) {
2066                               char *msg = "Transfer complete.";
2067                               off_t cnt, offset;
2068                               int err;
2069 
2070                               cnt = offset = 0;
2071 
2072                               while (filesize > 0) {
2073                                         err = sendfile(filefd, netfd, offset, 0,
2074                                                          NULL, &cnt, 0);
2075                                         /*
2076                                          * Calculate byte_count before OOB processing.
2077                                          * It can be used in myoob() later.
2078                                          */
2079                                         byte_count += cnt;
2080                                         offset += cnt;
2081                                         filesize -= cnt;
2082                                         CHECKOOB(return (-1))
2083                                         else if (err == -1) {
2084                                                   if (errno != EINTR &&
2085                                                       cnt == 0 && offset == 0)
2086                                                             goto oldway;
2087                                                   goto data_err;
2088                                         }
2089                                         if (err == -1)      /* resume after OOB */
2090                                                   continue;
2091                                         /*
2092                                          * We hit the EOF prematurely.
2093                                          * Perhaps the file was externally truncated.
2094                                          */
2095                                         if (cnt == 0) {
2096                                                   msg = "Transfer finished due to "
2097                                                         "premature end of file.";
2098                                                   break;
2099                                         }
2100                               }
2101                               ENDXFER;
2102                               reply(226, "%s", msg);
2103                               return (0);
2104                     }
2105 
2106 oldway:
2107                     if ((buf = malloc(blksize)) == NULL) {
2108                               ENDXFER;
2109                               reply(451, "Ran out of memory.");
2110                               return (-1);
2111                     }
2112 
2113                     for (;;) {
2114                               int cnt, len;
2115                               char *bp;
2116 
2117                               cnt = read(filefd, buf, blksize);
2118                               CHECKOOB(free(buf); return (-1))
2119                               else if (cnt < 0) {
2120                                         free(buf);
2121                                         goto file_err;
2122                               }
2123                               if (cnt < 0)        /* resume after OOB */
2124                                         continue;
2125                               if (cnt == 0)       /* EOF */
2126                                         break;
2127                               for (len = cnt, bp = buf; len > 0;) {
2128                                         cnt = write(netfd, bp, len);
2129                                         CHECKOOB(free(buf); return (-1))
2130                                         else if (cnt < 0) {
2131                                                   free(buf);
2132                                                   goto data_err;
2133                                         }
2134                                         if (cnt <= 0)
2135                                                   continue;
2136                                         len -= cnt;
2137                                         bp += cnt;
2138                                         byte_count += cnt;
2139                               }
2140                     }
2141                     ENDXFER;
2142                     free(buf);
2143                     reply(226, "Transfer complete.");
2144                     return (0);
2145           default:
2146                     ENDXFER;
2147                     reply(550, "Unimplemented TYPE %d in send_data.", type);
2148                     return (-1);
2149           }
2150 
2151 data_err:
2152           ENDXFER;
2153           perror_reply(426, "Data connection");
2154           return (-1);
2155 
2156 file_err:
2157           ENDXFER;
2158           perror_reply(551, "Error on input file");
2159           return (-1);
2160 }
2161 
2162 /*
2163  * Transfer data from peer to "outstr" using the appropriate encapulation of
2164  * the data subject to Mode, Structure, and Type.
2165  *
2166  * N.B.: Form isn't handled.
2167  */
2168 static int
receive_data(FILE * instr,FILE * outstr)2169 receive_data(FILE *instr, FILE *outstr)
2170 {
2171           int c, cp;
2172           int bare_lfs = 0;
2173 
2174           STARTXFER;
2175 
2176           switch (type) {
2177 
2178           case TYPE_I:
2179           case TYPE_L:
2180                     for (;;) {
2181                               int cnt, len;
2182                               char *bp;
2183                               char buf[BUFSIZ];
2184 
2185                               cnt = read(fileno(instr), buf, sizeof(buf));
2186                               CHECKOOB(return (-1))
2187                               else if (cnt < 0)
2188                                         goto data_err;
2189                               if (cnt < 0)        /* resume after OOB */
2190                                         continue;
2191                               if (cnt == 0)       /* EOF */
2192                                         break;
2193                               for (len = cnt, bp = buf; len > 0;) {
2194                                         cnt = write(fileno(outstr), bp, len);
2195                                         CHECKOOB(return (-1))
2196                                         else if (cnt < 0)
2197                                                   goto file_err;
2198                                         if (cnt <= 0)
2199                                                   continue;
2200                                         len -= cnt;
2201                                         bp += cnt;
2202                                         byte_count += cnt;
2203                               }
2204                     }
2205                     ENDXFER;
2206                     return (0);
2207 
2208           case TYPE_E:
2209                     ENDXFER;
2210                     reply(553, "TYPE E not implemented.");
2211                     return (-1);
2212 
2213           case TYPE_A:
2214                     cp = EOF;
2215                     for (;;) {
2216                               c = getc(instr);
2217                               CHECKOOB(return (-1))
2218                               else if (c == EOF && ferror(instr))
2219                                         goto data_err;
2220                               if (c == EOF && ferror(instr)) { /* resume after OOB */
2221                                         clearerr(instr);
2222                                         continue;
2223                               }
2224 
2225                               if (cp == '\r') {
2226                                         if (c != '\n')
2227                                                   FTPD_PUTC('\r', outstr, file_err);
2228                               } else
2229                                         if (c == '\n')
2230                                                   bare_lfs++;
2231                               if (c == '\r') {
2232                                         byte_count++;
2233                                         cp = c;
2234                                         continue;
2235                               }
2236 
2237                               /* Check for EOF here in order not to lose last \r. */
2238                               if (c == EOF) {
2239                                         if (feof(instr))    /* EOF */
2240                                                   break;
2241                                         syslog(LOG_ERR, "Internal: impossible condition"
2242                                                             " on data stream after getc()");
2243                                         goto data_err;
2244                               }
2245 
2246                               byte_count++;
2247                               FTPD_PUTC(c, outstr, file_err);
2248                               cp = c;
2249                     }
2250 #ifdef notyet       /* BSD stdio isn't ready for that */
2251                     while (fflush(outstr) == EOF) {
2252                               CHECKOOB(return (-1))
2253                               else
2254                                         goto file_err;
2255                               clearerr(outstr);
2256                     }
2257                     ENDXFER;
2258 #else
2259                     ENDXFER;
2260                     if (fflush(outstr) == EOF)
2261                               goto file_err;
2262 #endif
2263                     if (bare_lfs) {
2264                               lreply(226,
2265                     "WARNING! %d bare linefeeds received in ASCII mode.",
2266                                   bare_lfs);
2267                     printf("   File may not have transferred correctly.\r\n");
2268                     }
2269                     return (0);
2270           default:
2271                     ENDXFER;
2272                     reply(550, "Unimplemented TYPE %d in receive_data.", type);
2273                     return (-1);
2274           }
2275 
2276 data_err:
2277           ENDXFER;
2278           perror_reply(426, "Data connection");
2279           return (-1);
2280 
2281 file_err:
2282           ENDXFER;
2283           perror_reply(452, "Error writing to file");
2284           return (-1);
2285 }
2286 
2287 void
statfilecmd(char * filename)2288 statfilecmd(char *filename)
2289 {
2290           FILE *fin;
2291           int atstart;
2292           int c, code;
2293           char line[LINE_MAX];
2294           struct stat st;
2295 
2296           code = lstat(filename, &st) == 0 && S_ISDIR(st.st_mode) ? 212 : 213;
2297           snprintf(line, sizeof(line), _PATH_LS " -lgA %s", filename);
2298           fin = ftpd_popen(line, "r");
2299           lreply(code, "Status of %s:", filename);
2300           atstart = 1;
2301           while ((c = getc(fin)) != EOF) {
2302                     if (c == '\n') {
2303                               if (ferror(stdout)){
2304                                         perror_reply(421, "Control connection");
2305                                         ftpd_pclose(fin);
2306                                         dologout(1);
2307                                         /* NOTREACHED */
2308                               }
2309                               if (ferror(fin)) {
2310                                         perror_reply(551, filename);
2311                                         ftpd_pclose(fin);
2312                                         return;
2313                               }
2314                               putc('\r', stdout);
2315                     }
2316                     /*
2317                      * RFC 959 says neutral text should be prepended before
2318                      * a leading 3-digit number followed by whitespace, but
2319                      * many ftp clients can be confused by any leading digits,
2320                      * as a matter of fact.
2321                      */
2322                     if (atstart && isdigit(c))
2323                               putc(' ', stdout);
2324                     putc(c, stdout);
2325                     atstart = (c == '\n');
2326           }
2327           ftpd_pclose(fin);
2328           reply(code, "End of status.");
2329 }
2330 
2331 void
statcmd(void)2332 statcmd(void)
2333 {
2334           union sockunion *su;
2335           u_char *a, *p;
2336           char hname[NI_MAXHOST];
2337           int ispassive;
2338 
2339           if (hostinfo) {
2340                     lreply(211, "%s FTP server status:", hostname);
2341                     printf("     %s\r\n", version);
2342           } else
2343                     lreply(211, "FTP server status:");
2344           printf("     Connected to %s", remotehost);
2345           if (!getnameinfo((struct sockaddr *)&his_addr, his_addr.su_len,
2346                                hname, sizeof(hname) - 1, NULL, 0, NI_NUMERICHOST)) {
2347                     hname[sizeof(hname) - 1] = 0;
2348                     if (strcmp(hname, remotehost) != 0)
2349                               printf(" (%s)", hname);
2350           }
2351           printf("\r\n");
2352           if (logged_in) {
2353                     if (guest)
2354                               printf("     Logged in anonymously\r\n");
2355                     else
2356                               printf("     Logged in as %s\r\n", pw->pw_name);
2357           } else if (askpasswd)
2358                     printf("     Waiting for password\r\n");
2359           else
2360                     printf("     Waiting for user name\r\n");
2361           printf("     TYPE: %s", typenames[type]);
2362           if (type == TYPE_A || type == TYPE_E)
2363                     printf(", FORM: %s", formnames[form]);
2364           if (type == TYPE_L)
2365 #if CHAR_BIT == 8
2366                     printf(" %d", CHAR_BIT);
2367 #else
2368                     printf(" %d", bytesize);      /* need definition! */
2369 #endif
2370           printf("; STRUcture: %s; transfer MODE: %s\r\n",
2371               strunames[stru], modenames[mode]);
2372           if (data != -1)
2373                     printf("     Data connection open\r\n");
2374           else if (pdata != -1) {
2375                     ispassive = 1;
2376                     su = &pasv_addr;
2377                     goto printaddr;
2378           } else if (usedefault == 0) {
2379                     ispassive = 0;
2380                     su = &data_dest;
2381 printaddr:
2382 #define UC(b) (((int) b) & 0xff)
2383                     if (epsvall) {
2384                               printf("     EPSV only mode (EPSV ALL)\r\n");
2385                               goto epsvonly;
2386                     }
2387 
2388                     /* PORT/PASV */
2389                     if (su->su_family == AF_INET) {
2390                               a = (u_char *) &su->su_sin.sin_addr;
2391                               p = (u_char *) &su->su_sin.sin_port;
2392                               printf("     %s (%d,%d,%d,%d,%d,%d)\r\n",
2393                                         ispassive ? "PASV" : "PORT",
2394                                         UC(a[0]), UC(a[1]), UC(a[2]), UC(a[3]),
2395                                         UC(p[0]), UC(p[1]));
2396                     }
2397 
2398                     /* LPRT/LPSV */
2399               {
2400                     int alen, af, i;
2401 
2402                     switch (su->su_family) {
2403                     case AF_INET:
2404                               a = (u_char *) &su->su_sin.sin_addr;
2405                               p = (u_char *) &su->su_sin.sin_port;
2406                               alen = sizeof(su->su_sin.sin_addr);
2407                               af = 4;
2408                               break;
2409                     case AF_INET6:
2410                               a = (u_char *) &su->su_sin6.sin6_addr;
2411                               p = (u_char *) &su->su_sin6.sin6_port;
2412                               alen = sizeof(su->su_sin6.sin6_addr);
2413                               af = 6;
2414                               break;
2415                     default:
2416                               af = 0;
2417                               break;
2418                     }
2419                     if (af) {
2420                               printf("     %s (%d,%d,", ispassive ? "LPSV" : "LPRT",
2421                                         af, alen);
2422                               for (i = 0; i < alen; i++)
2423                                         printf("%d,", UC(a[i]));
2424                               printf("%d,%d,%d)\r\n", 2, UC(p[0]), UC(p[1]));
2425                     }
2426               }
2427 
2428 epsvonly:;
2429                     /* EPRT/EPSV */
2430               {
2431                     int af;
2432 
2433                     switch (su->su_family) {
2434                     case AF_INET:
2435                               af = 1;
2436                               break;
2437                     case AF_INET6:
2438                               af = 2;
2439                               break;
2440                     default:
2441                               af = 0;
2442                               break;
2443                     }
2444                     if (af) {
2445                               union sockunion tmp;
2446 
2447                               tmp = *su;
2448                               if (tmp.su_family == AF_INET6)
2449                                         tmp.su_sin6.sin6_scope_id = 0;
2450                               if (!getnameinfo((struct sockaddr *)&tmp, tmp.su_len,
2451                                                   hname, sizeof(hname) - 1, NULL, 0,
2452                                                   NI_NUMERICHOST)) {
2453                                         hname[sizeof(hname) - 1] = 0;
2454                                         printf("     %s |%d|%s|%d|\r\n",
2455                                                   ispassive ? "EPSV" : "EPRT",
2456                                                   af, hname, htons(tmp.su_port));
2457                               }
2458                     }
2459               }
2460 #undef UC
2461           } else
2462                     printf("     No data connection\r\n");
2463           reply(211, "End of status.");
2464 }
2465 
2466 void
fatalerror(char * s)2467 fatalerror(char *s)
2468 {
2469 
2470           reply(451, "Error in server: %s", s);
2471           reply(221, "Closing connection due to server error.");
2472           dologout(0);
2473           /* NOTREACHED */
2474 }
2475 
2476 void
reply(int n,const char * fmt,...)2477 reply(int n, const char *fmt, ...)
2478 {
2479           va_list ap;
2480 
2481           printf("%d ", n);
2482           va_start(ap, fmt);
2483           vprintf(fmt, ap);
2484           va_end(ap);
2485           printf("\r\n");
2486           fflush(stdout);
2487           if (ftpdebug) {
2488                     syslog(LOG_DEBUG, "<--- %d ", n);
2489                     va_start(ap, fmt);
2490                     vsyslog(LOG_DEBUG, fmt, ap);
2491                     va_end(ap);
2492           }
2493 }
2494 
2495 void
lreply(int n,const char * fmt,...)2496 lreply(int n, const char *fmt, ...)
2497 {
2498           va_list ap;
2499 
2500           printf("%d- ", n);
2501           va_start(ap, fmt);
2502           vprintf(fmt, ap);
2503           va_end(ap);
2504           printf("\r\n");
2505           fflush(stdout);
2506           if (ftpdebug) {
2507                     syslog(LOG_DEBUG, "<--- %d- ", n);
2508                     va_start(ap, fmt);
2509                     vsyslog(LOG_DEBUG, fmt, ap);
2510                     va_end(ap);
2511           }
2512 }
2513 
2514 static void
ack(char * s)2515 ack(char *s)
2516 {
2517 
2518           reply(250, "%s command successful.", s);
2519 }
2520 
2521 void
nack(char * s)2522 nack(char *s)
2523 {
2524 
2525           reply(502, "%s command not implemented.", s);
2526 }
2527 
2528 /* ARGSUSED */
2529 void
yyerror(char * s)2530 yyerror(char *s)
2531 {
2532           char *cp;
2533 
2534           if ((cp = strchr(cbuf,'\n')))
2535                     *cp = '\0';
2536           reply(500, "%s: command not understood.", cbuf);
2537 }
2538 
2539 void
delete(char * name)2540 delete(char *name)
2541 {
2542           struct stat st;
2543 
2544           LOGCMD("delete", name);
2545           if (lstat(name, &st) < 0) {
2546                     perror_reply(550, name);
2547                     return;
2548           }
2549           if (S_ISDIR(st.st_mode)) {
2550                     if (rmdir(name) < 0) {
2551                               perror_reply(550, name);
2552                               return;
2553                     }
2554                     goto done;
2555           }
2556           if (guest && noguestmod) {
2557                     reply(550, "Operation not permitted.");
2558                     return;
2559           }
2560           if (unlink(name) < 0) {
2561                     perror_reply(550, name);
2562                     return;
2563           }
2564 done:
2565           ack("DELE");
2566 }
2567 
2568 void
cwd(char * path)2569 cwd(char *path)
2570 {
2571 
2572           if (chdir(path) < 0)
2573                     perror_reply(550, path);
2574           else
2575                     ack("CWD");
2576 }
2577 
2578 void
makedir(char * name)2579 makedir(char *name)
2580 {
2581           char *s;
2582 
2583           LOGCMD("mkdir", name);
2584           if (guest && noguestmkd)
2585                     reply(550, "Operation not permitted.");
2586           else if (mkdir(name, 0777) < 0)
2587                     perror_reply(550, name);
2588           else {
2589                     if ((s = doublequote(name)) == NULL)
2590                               fatalerror("Ran out of memory.");
2591                     reply(257, "\"%s\" directory created.", s);
2592                     free(s);
2593           }
2594 }
2595 
2596 void
removedir(char * name)2597 removedir(char *name)
2598 {
2599 
2600           LOGCMD("rmdir", name);
2601           if (rmdir(name) < 0)
2602                     perror_reply(550, name);
2603           else
2604                     ack("RMD");
2605 }
2606 
2607 void
pwd(void)2608 pwd(void)
2609 {
2610           char *s, path[MAXPATHLEN + 1];
2611 
2612           if (getcwd(path, sizeof(path)) == NULL)
2613                     perror_reply(550, "Get current directory");
2614           else {
2615                     if ((s = doublequote(path)) == NULL)
2616                               fatalerror("Ran out of memory.");
2617                     reply(257, "\"%s\" is current directory.", s);
2618                     free(s);
2619           }
2620 }
2621 
2622 char *
renamefrom(char * name)2623 renamefrom(char *name)
2624 {
2625           struct stat st;
2626 
2627           if (guest && noguestmod) {
2628                     reply(550, "Operation not permitted.");
2629                     return (NULL);
2630           }
2631           if (lstat(name, &st) < 0) {
2632                     perror_reply(550, name);
2633                     return (NULL);
2634           }
2635           reply(350, "File exists, ready for destination name.");
2636           return (name);
2637 }
2638 
2639 void
renamecmd(char * from,char * to)2640 renamecmd(char *from, char *to)
2641 {
2642           struct stat st;
2643 
2644           LOGCMD2("rename", from, to);
2645 
2646           if (guest && (stat(to, &st) == 0)) {
2647                     reply(550, "%s: permission denied.", to);
2648                     return;
2649           }
2650 
2651           if (rename(from, to) < 0)
2652                     perror_reply(550, "rename");
2653           else
2654                     ack("RNTO");
2655 }
2656 
2657 static void
dolog(struct sockaddr * who)2658 dolog(struct sockaddr *who)
2659 {
2660           char who_name[NI_MAXHOST];
2661 
2662           realhostname_sa(remotehost, sizeof(remotehost) - 1, who, who->sa_len);
2663           remotehost[sizeof(remotehost) - 1] = 0;
2664           if (getnameinfo(who, who->sa_len,
2665                     who_name, sizeof(who_name) - 1, NULL, 0, NI_NUMERICHOST))
2666                               *who_name = 0;
2667           who_name[sizeof(who_name) - 1] = 0;
2668 
2669 #ifdef SETPROCTITLE
2670 #ifdef VIRTUAL_HOSTING
2671           if (thishost != firsthost)
2672                     snprintf(proctitle, sizeof(proctitle), "%s: connected (to %s)",
2673                                remotehost, hostname);
2674           else
2675 #endif
2676                     snprintf(proctitle, sizeof(proctitle), "%s: connected",
2677                                remotehost);
2678           setproctitle("%s", proctitle);
2679 #endif /* SETPROCTITLE */
2680 
2681           if (logging) {
2682 #ifdef VIRTUAL_HOSTING
2683                     if (thishost != firsthost)
2684                               syslog(LOG_INFO, "connection from %s (%s) to %s",
2685                                      remotehost, who_name, hostname);
2686                     else
2687 #endif
2688                               syslog(LOG_INFO, "connection from %s (%s)",
2689                                      remotehost, who_name);
2690           }
2691 }
2692 
2693 /*
2694  * Record logout in wtmpx file
2695  * and exit with supplied status.
2696  */
2697 void
dologout(int status)2698 dologout(int status)
2699 {
2700 
2701           if (logged_in && dowtmpx) {
2702                     seteuid(0);
2703                     ftpd_logwtmpx(ttyline, "", NULL);
2704           }
2705           /* beware of flushing buffers after a SIGPIPE */
2706           _exit(status);
2707 }
2708 
2709 static void
sigurg(int signo)2710 sigurg(int signo)
2711 {
2712 
2713           recvurg = 1;
2714 }
2715 
2716 static void
maskurg(int flag)2717 maskurg(int flag)
2718 {
2719           int oerrno;
2720           sigset_t sset;
2721 
2722           if (!transflag) {
2723                     syslog(LOG_ERR, "Internal: maskurg() while no transfer");
2724                     return;
2725           }
2726           oerrno = errno;
2727           sigemptyset(&sset);
2728           sigaddset(&sset, SIGURG);
2729           sigprocmask(flag ? SIG_BLOCK : SIG_UNBLOCK, &sset, NULL);
2730           errno = oerrno;
2731 }
2732 
2733 static void
flagxfer(int flag)2734 flagxfer(int flag)
2735 {
2736 
2737           if (flag) {
2738                     if (transflag)
2739                               syslog(LOG_ERR, "Internal: flagxfer(1): "
2740                                                   "transfer already under way");
2741                     transflag = 1;
2742                     maskurg(0);
2743                     recvurg = 0;
2744           } else {
2745                     if (!transflag)
2746                               syslog(LOG_ERR, "Internal: flagxfer(0): "
2747                                                   "no active transfer");
2748                     maskurg(1);
2749                     transflag = 0;
2750           }
2751 }
2752 
2753 /*
2754  * Returns 0 if OK to resume or -1 if abort requested.
2755  */
2756 static int
myoob(void)2757 myoob(void)
2758 {
2759           char *cp;
2760           int ret;
2761 
2762           if (!transflag) {
2763                     syslog(LOG_ERR, "Internal: myoob() while no transfer");
2764                     return (0);
2765           }
2766           cp = tmpline;
2767           ret = get_line(cp, 7, stdin);
2768           if (ret == -1) {
2769                     reply(221, "You could at least say goodbye.");
2770                     dologout(0);
2771           } else if (ret == -2) {
2772                     /* Ignore truncated command. */
2773                     return (0);
2774           }
2775           upper(cp);
2776           if (strcmp(cp, "ABOR\r\n") == 0) {
2777                     tmpline[0] = '\0';
2778                     reply(426, "Transfer aborted. Data connection closed.");
2779                     reply(226, "Abort successful.");
2780                     return (-1);
2781           }
2782           if (strcmp(cp, "STAT\r\n") == 0) {
2783                     tmpline[0] = '\0';
2784                     if (file_size != -1)
2785                               reply(213, "Status: %jd of %jd bytes transferred.",
2786                                            (intmax_t)byte_count, (intmax_t)file_size);
2787                     else
2788                               reply(213, "Status: %jd bytes transferred.",
2789                                            (intmax_t)byte_count);
2790           }
2791           return (0);
2792 }
2793 
2794 /*
2795  * Note: a response of 425 is not mentioned as a possible response to
2796  *        the PASV command in RFC959. However, it has been blessed as
2797  *        a legitimate response by Jon Postel in a telephone conversation
2798  *        with Rick Adams on 25 Jan 89.
2799  */
2800 void
passive(void)2801 passive(void)
2802 {
2803           socklen_t len;
2804           int on;
2805           char *p, *a;
2806 
2807           if (pdata >= 0)               /* close old port if one set */
2808                     close(pdata);
2809 
2810           pdata = socket(ctrl_addr.su_family, SOCK_STREAM, 0);
2811           if (pdata < 0) {
2812                     perror_reply(425, "Can't open passive connection");
2813                     return;
2814           }
2815           on = 1;
2816           if (setsockopt(pdata, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
2817                     syslog(LOG_WARNING, "pdata setsockopt (SO_REUSEADDR): %m");
2818 
2819           seteuid(0);
2820 
2821 #ifdef IP_PORTRANGE
2822           if (ctrl_addr.su_family == AF_INET) {
2823               on = restricted_data_ports ? IP_PORTRANGE_HIGH
2824                                                : IP_PORTRANGE_DEFAULT;
2825 
2826               if (setsockopt(pdata, IPPROTO_IP, IP_PORTRANGE,
2827                                   &on, sizeof(on)) < 0)
2828                         goto pasv_error;
2829           }
2830 #endif
2831 #ifdef IPV6_PORTRANGE
2832           if (ctrl_addr.su_family == AF_INET6) {
2833               on = restricted_data_ports ? IPV6_PORTRANGE_HIGH
2834                                                : IPV6_PORTRANGE_DEFAULT;
2835 
2836               if (setsockopt(pdata, IPPROTO_IPV6, IPV6_PORTRANGE,
2837                                   &on, sizeof(on)) < 0)
2838                         goto pasv_error;
2839           }
2840 #endif
2841 
2842           pasv_addr = ctrl_addr;
2843           pasv_addr.su_port = 0;
2844           if (bind(pdata, (struct sockaddr *)&pasv_addr, pasv_addr.su_len) < 0)
2845                     goto pasv_error;
2846 
2847           seteuid(pw->pw_uid);
2848 
2849           len = sizeof(pasv_addr);
2850           if (getsockname(pdata, (struct sockaddr *) &pasv_addr, &len) < 0)
2851                     goto pasv_error;
2852           if (listen(pdata, 1) < 0)
2853                     goto pasv_error;
2854           if (pasv_addr.su_family == AF_INET)
2855                     a = (char *) &pasv_addr.su_sin.sin_addr;
2856           else if (pasv_addr.su_family == AF_INET6 &&
2857                      IN6_IS_ADDR_V4MAPPED(&pasv_addr.su_sin6.sin6_addr))
2858                     a = (char *) &pasv_addr.su_sin6.sin6_addr.s6_addr[12];
2859           else
2860                     goto pasv_error;
2861 
2862           p = (char *) &pasv_addr.su_port;
2863 
2864 #define UC(b) (((int) b) & 0xff)
2865 
2866           reply(227, "Entering Passive Mode (%d,%d,%d,%d,%d,%d)", UC(a[0]),
2867                     UC(a[1]), UC(a[2]), UC(a[3]), UC(p[0]), UC(p[1]));
2868           return;
2869 
2870 pasv_error:
2871           seteuid(pw->pw_uid);
2872           close(pdata);
2873           pdata = -1;
2874           perror_reply(425, "Can't open passive connection");
2875           return;
2876 }
2877 
2878 /*
2879  * Long Passive defined in RFC 1639.
2880  *     228 Entering Long Passive Mode
2881  *         (af, hal, h1, h2, h3,..., pal, p1, p2...)
2882  */
2883 
2884 void
long_passive(char * cmd,int pf)2885 long_passive(char *cmd, int pf)
2886 {
2887           socklen_t len;
2888           int on;
2889           char *p, *a;
2890 
2891           if (pdata >= 0)               /* close old port if one set */
2892                     close(pdata);
2893 
2894           if (pf != PF_UNSPEC) {
2895                     if (ctrl_addr.su_family != pf) {
2896                               switch (ctrl_addr.su_family) {
2897                               case AF_INET:
2898                                         pf = 1;
2899                                         break;
2900                               case AF_INET6:
2901                                         pf = 2;
2902                                         break;
2903                               default:
2904                                         pf = 0;
2905                                         break;
2906                               }
2907                               /*
2908                                * XXX
2909                                * only EPRT/EPSV ready clients will understand this
2910                                */
2911                               if (strcmp(cmd, "EPSV") == 0 && pf) {
2912                                         reply(522, "Network protocol mismatch, "
2913                                                   "use (%d)", pf);
2914                               } else
2915                                         reply(501, "Network protocol mismatch."); /*XXX*/
2916 
2917                               return;
2918                     }
2919           }
2920 
2921           pdata = socket(ctrl_addr.su_family, SOCK_STREAM, 0);
2922           if (pdata < 0) {
2923                     perror_reply(425, "Can't open passive connection");
2924                     return;
2925           }
2926           on = 1;
2927           if (setsockopt(pdata, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
2928                     syslog(LOG_WARNING, "pdata setsockopt (SO_REUSEADDR): %m");
2929 
2930           seteuid(0);
2931 
2932           pasv_addr = ctrl_addr;
2933           pasv_addr.su_port = 0;
2934           len = pasv_addr.su_len;
2935 
2936 #ifdef IP_PORTRANGE
2937           if (ctrl_addr.su_family == AF_INET) {
2938               on = restricted_data_ports ? IP_PORTRANGE_HIGH
2939                                                : IP_PORTRANGE_DEFAULT;
2940 
2941               if (setsockopt(pdata, IPPROTO_IP, IP_PORTRANGE,
2942                                   &on, sizeof(on)) < 0)
2943                         goto pasv_error;
2944           }
2945 #endif
2946 #ifdef IPV6_PORTRANGE
2947           if (ctrl_addr.su_family == AF_INET6) {
2948               on = restricted_data_ports ? IPV6_PORTRANGE_HIGH
2949                                                : IPV6_PORTRANGE_DEFAULT;
2950 
2951               if (setsockopt(pdata, IPPROTO_IPV6, IPV6_PORTRANGE,
2952                                   &on, sizeof(on)) < 0)
2953                         goto pasv_error;
2954           }
2955 #endif
2956 
2957           if (bind(pdata, (struct sockaddr *)&pasv_addr, len) < 0)
2958                     goto pasv_error;
2959 
2960           seteuid(pw->pw_uid);
2961 
2962           if (getsockname(pdata, (struct sockaddr *) &pasv_addr, &len) < 0)
2963                     goto pasv_error;
2964           if (listen(pdata, 1) < 0)
2965                     goto pasv_error;
2966 
2967 #define UC(b) (((int) b) & 0xff)
2968 
2969           if (strcmp(cmd, "LPSV") == 0) {
2970                     p = (char *)&pasv_addr.su_port;
2971                     switch (pasv_addr.su_family) {
2972                     case AF_INET:
2973                               a = (char *) &pasv_addr.su_sin.sin_addr;
2974                     v4_reply:
2975                               reply(228,
2976 "Entering Long Passive Mode (%d,%d,%d,%d,%d,%d,%d,%d,%d)",
2977                                     4, 4, UC(a[0]), UC(a[1]), UC(a[2]), UC(a[3]),
2978                                     2, UC(p[0]), UC(p[1]));
2979                               return;
2980                     case AF_INET6:
2981                               if (IN6_IS_ADDR_V4MAPPED(&pasv_addr.su_sin6.sin6_addr)) {
2982                                         a = (char *) &pasv_addr.su_sin6.sin6_addr.s6_addr[12];
2983                                         goto v4_reply;
2984                               }
2985                               a = (char *) &pasv_addr.su_sin6.sin6_addr;
2986                               reply(228,
2987 "Entering Long Passive Mode "
2988 "(%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d)",
2989                                     6, 16, UC(a[0]), UC(a[1]), UC(a[2]), UC(a[3]),
2990                                     UC(a[4]), UC(a[5]), UC(a[6]), UC(a[7]),
2991                                     UC(a[8]), UC(a[9]), UC(a[10]), UC(a[11]),
2992                                     UC(a[12]), UC(a[13]), UC(a[14]), UC(a[15]),
2993                                     2, UC(p[0]), UC(p[1]));
2994                               return;
2995                     }
2996           } else if (strcmp(cmd, "EPSV") == 0) {
2997                     switch (pasv_addr.su_family) {
2998                     case AF_INET:
2999                     case AF_INET6:
3000                               reply(229, "Entering Extended Passive Mode (|||%d|)",
3001                                         ntohs(pasv_addr.su_port));
3002                               return;
3003                     }
3004           } else {
3005                     /* more proper error code? */
3006           }
3007 
3008 pasv_error:
3009           seteuid(pw->pw_uid);
3010           close(pdata);
3011           pdata = -1;
3012           perror_reply(425, "Can't open passive connection");
3013           return;
3014 }
3015 
3016 /*
3017  * Generate unique name for file with basename "local"
3018  * and open the file in order to avoid possible races.
3019  * Try "local" first, then "local.1", "local.2" etc, up to "local.99".
3020  * Return descriptor to the file, set "name" to its name.
3021  *
3022  * Generates failure reply on error.
3023  */
3024 static int
guniquefd(char * local,char ** name)3025 guniquefd(char *local, char **name)
3026 {
3027           static char new[MAXPATHLEN];
3028           struct stat st;
3029           char *cp;
3030           int count;
3031           int fd;
3032 
3033           cp = strrchr(local, '/');
3034           if (cp)
3035                     *cp = '\0';
3036           if (stat(cp ? local : ".", &st) < 0) {
3037                     perror_reply(553, cp ? local : ".");
3038                     return (-1);
3039           }
3040           if (cp) {
3041                     /*
3042                      * Let not overwrite dirname with counter suffix.
3043                      * -4 is for /nn\0
3044                      * In this extreme case dot won't be put in front of suffix.
3045                      */
3046                     if (strlen(local) > sizeof(new) - 4) {
3047                               reply(553, "Pathname too long.");
3048                               return (-1);
3049                     }
3050                     *cp = '/';
3051           }
3052           /* -4 is for the .nn<null> we put on the end below */
3053           snprintf(new, sizeof(new) - 4, "%s", local);
3054           cp = new + strlen(new);
3055           /*
3056            * Don't generate dotfile unless requested explicitly.
3057            * This covers the case when basename gets truncated off
3058            * by buffer size.
3059            */
3060           if (cp > new && cp[-1] != '/')
3061                     *cp++ = '.';
3062           for (count = 0; count < 100; count++) {
3063                     /* At count 0 try unmodified name */
3064                     if (count)
3065                               sprintf(cp, "%d", count);
3066                     if ((fd = open(count ? new : local,
3067                         O_RDWR | O_CREAT | O_EXCL, 0666)) >= 0) {
3068                               *name = count ? new : local;
3069                               return (fd);
3070                     }
3071                     if (errno != EEXIST) {
3072                               perror_reply(553, count ? new : local);
3073                               return (-1);
3074                     }
3075           }
3076           reply(452, "Unique file name cannot be created.");
3077           return (-1);
3078 }
3079 
3080 /*
3081  * Format and send reply containing system error number.
3082  */
3083 void
perror_reply(int code,char * string)3084 perror_reply(int code, char *string)
3085 {
3086 
3087           reply(code, "%s: %s.", string, strerror(errno));
3088 }
3089 
3090 static char *onefile[] = {
3091           "",
3092           0
3093 };
3094 
3095 void
send_file_list(char * whichf)3096 send_file_list(char *whichf)
3097 {
3098           struct stat st;
3099           DIR *dirp = NULL;
3100           struct dirent *dir;
3101           FILE *dout = NULL;
3102           char **dirlist, *dirname;
3103           int simple = 0;
3104           int freeglob = 0;
3105           glob_t gl;
3106 
3107           if (strpbrk(whichf, "~{[*?") != NULL) {
3108                     int flags = GLOB_BRACE|GLOB_NOCHECK|GLOB_TILDE;
3109 
3110                     memset(&gl, 0, sizeof(gl));
3111                     gl.gl_matchc = MAXGLOBARGS;
3112                     /*flags |= GLOB_LIMIT;*/
3113                     freeglob = 1;
3114                     if (glob(whichf, flags, 0, &gl)) {
3115                               reply(550, "No matching files found.");
3116                               goto out;
3117                     } else if (gl.gl_pathc == 0) {
3118                               errno = ENOENT;
3119                               perror_reply(550, whichf);
3120                               goto out;
3121                     }
3122                     dirlist = gl.gl_pathv;
3123           } else {
3124                     onefile[0] = whichf;
3125                     dirlist = onefile;
3126                     simple = 1;
3127           }
3128 
3129           while ((dirname = *dirlist++)) {
3130                     if (stat(dirname, &st) < 0) {
3131                               /*
3132                                * If user typed "ls -l", etc, and the client
3133                                * used NLST, do what the user meant.
3134                                */
3135                               if (dirname[0] == '-' && *dirlist == NULL &&
3136                                   dout == NULL)
3137                                         retrieve(_PATH_LS " %s", dirname);
3138                               else
3139                                         perror_reply(550, whichf);
3140                               goto out;
3141                     }
3142 
3143                     if (S_ISREG(st.st_mode)) {
3144                               if (dout == NULL) {
3145                                         dout = dataconn("file list", -1, "w");
3146                                         if (dout == NULL)
3147                                                   goto out;
3148                                         STARTXFER;
3149                               }
3150                               START_UNSAFE;
3151                               fprintf(dout, "%s%s\n", dirname,
3152                                         type == TYPE_A ? "\r" : "");
3153                               END_UNSAFE;
3154                               if (ferror(dout))
3155                                         goto data_err;
3156                               byte_count += strlen(dirname) +
3157                                               (type == TYPE_A ? 2 : 1);
3158                               CHECKOOB(goto abrt);
3159                               continue;
3160                     } else if (!S_ISDIR(st.st_mode))
3161                               continue;
3162 
3163                     if ((dirp = opendir(dirname)) == NULL)
3164                               continue;
3165 
3166                     while ((dir = readdir(dirp)) != NULL) {
3167                               char nbuf[MAXPATHLEN];
3168 
3169                               CHECKOOB(goto abrt);
3170 
3171                               if (strcmp(dir->d_name, ".") == 0)
3172                                         continue;
3173                               if (strcmp(dir->d_name, "..") == 0)
3174                                         continue;
3175 
3176                               snprintf(nbuf, sizeof(nbuf),
3177                                         "%s/%s", dirname, dir->d_name);
3178 
3179                               /*
3180                                * We have to do a stat to insure it's
3181                                * not a directory or special file.
3182                                */
3183                               if (simple || (stat(nbuf, &st) == 0 &&
3184                                   S_ISREG(st.st_mode))) {
3185                                         if (dout == NULL) {
3186                                                   dout = dataconn("file list", -1, "w");
3187                                                   if (dout == NULL)
3188                                                             goto out;
3189                                                   STARTXFER;
3190                                         }
3191                                         START_UNSAFE;
3192                                         if (nbuf[0] == '.' && nbuf[1] == '/')
3193                                                   fprintf(dout, "%s%s\n", &nbuf[2],
3194                                                             type == TYPE_A ? "\r" : "");
3195                                         else
3196                                                   fprintf(dout, "%s%s\n", nbuf,
3197                                                             type == TYPE_A ? "\r" : "");
3198                                         END_UNSAFE;
3199                                         if (ferror(dout))
3200                                                   goto data_err;
3201                                         byte_count += strlen(nbuf) +
3202                                                         (type == TYPE_A ? 2 : 1);
3203                                         CHECKOOB(goto abrt);
3204                               }
3205                     }
3206                     closedir(dirp);
3207                     dirp = NULL;
3208           }
3209 
3210           if (dout == NULL)
3211                     reply(550, "No files found.");
3212           else if (ferror(dout))
3213 data_err: perror_reply(550, "Data connection");
3214           else
3215                     reply(226, "Transfer complete.");
3216 out:
3217           if (dout) {
3218                     ENDXFER;
3219 abrt:
3220                     fclose(dout);
3221                     data = -1;
3222                     pdata = -1;
3223           }
3224           if (dirp)
3225                     closedir(dirp);
3226           if (freeglob) {
3227                     freeglob = 0;
3228                     globfree(&gl);
3229           }
3230 }
3231 
3232 void
reapchild(int signo)3233 reapchild(int signo)
3234 {
3235           while (waitpid(-1, NULL, WNOHANG) > 0);
3236 }
3237 
3238 static void
appendf(char ** strp,char * fmt,...)3239 appendf(char **strp, char *fmt, ...)
3240 {
3241           va_list ap;
3242           char *ostr, *p;
3243 
3244           va_start(ap, fmt);
3245           vasprintf(&p, fmt, ap);
3246           va_end(ap);
3247           if (p == NULL)
3248                     fatalerror("Ran out of memory.");
3249           if (*strp == NULL)
3250                     *strp = p;
3251           else {
3252                     ostr = *strp;
3253                     asprintf(strp, "%s%s", ostr, p);
3254                     if (*strp == NULL)
3255                               fatalerror("Ran out of memory.");
3256                     free(ostr);
3257           }
3258 }
3259 
3260 static void
logcmd(char * cmd,char * file1,char * file2,off_t cnt)3261 logcmd(char *cmd, char *file1, char *file2, off_t cnt)
3262 {
3263           char *msg = NULL;
3264           char wd[MAXPATHLEN + 1];
3265 
3266           if (logging <= 1)
3267                     return;
3268 
3269           if (getcwd(wd, sizeof(wd) - 1) == NULL)
3270                     strcpy(wd, strerror(errno));
3271 
3272           appendf(&msg, "%s", cmd);
3273           if (file1)
3274                     appendf(&msg, " %s", file1);
3275           if (file2)
3276                     appendf(&msg, " %s", file2);
3277           if (cnt >= 0)
3278                     appendf(&msg, " = %jd bytes", (intmax_t)cnt);
3279           appendf(&msg, " (wd: %s", wd);
3280           if (guest || dochroot)
3281                     appendf(&msg, "; chrooted");
3282           appendf(&msg, ")");
3283           syslog(LOG_INFO, "%s", msg);
3284           free(msg);
3285 }
3286 
3287 static void
logxfer(char * name,off_t size,time_t start)3288 logxfer(char *name, off_t size, time_t start)
3289 {
3290           char buf[MAXPATHLEN + 1024];
3291           char path[MAXPATHLEN + 1];
3292           time_t now;
3293 
3294           if (statfd >= 0) {
3295                     time(&now);
3296                     if (realpath(name, path) == NULL) {
3297                               syslog(LOG_NOTICE, "realpath failed on %s: %m", path);
3298                               return;
3299                     }
3300                     snprintf(buf, sizeof(buf), "%.20s!%s!%s!%s!%jd!%ld\n",
3301                               ctime(&now)+4, ident, remotehost,
3302                               path, (intmax_t)size,
3303                               (long)(now - start + (now == start)));
3304                     write(statfd, buf, strlen(buf));
3305           }
3306 }
3307 
3308 static char *
doublequote(char * s)3309 doublequote(char *s)
3310 {
3311           int n;
3312           char *p, *s2;
3313 
3314           for (p = s, n = 0; *p; p++)
3315                     if (*p == '"')
3316                               n++;
3317 
3318           if ((s2 = malloc(p - s + n + 1)) == NULL)
3319                     return (NULL);
3320 
3321           for (p = s2; *s; s++, p++) {
3322                     if ((*p = *s) == '"')
3323                               *(++p) = '"';
3324           }
3325           *p = '\0';
3326 
3327           return (s2);
3328 }
3329 
3330 /* setup server socket for specified address family */
3331 /* if af is PF_UNSPEC more than one socket may be returned */
3332 /* the returned list is dynamically allocated, so caller needs to free it */
3333 static int *
socksetup(int af,char * bindname,const char * bindport)3334 socksetup(int af, char *bindname, const char *bindport)
3335 {
3336           struct addrinfo hints, *res, *r;
3337           int error, maxs, *s, *socks;
3338           const int on = 1;
3339 
3340           memset(&hints, 0, sizeof(hints));
3341           hints.ai_flags = AI_PASSIVE;
3342           hints.ai_family = af;
3343           hints.ai_socktype = SOCK_STREAM;
3344           error = getaddrinfo(bindname, bindport, &hints, &res);
3345           if (error) {
3346                     syslog(LOG_ERR, "%s", gai_strerror(error));
3347                     if (error == EAI_SYSTEM)
3348                               syslog(LOG_ERR, "%s", strerror(errno));
3349                     return NULL;
3350           }
3351 
3352           /* Count max number of sockets we may open */
3353           for (maxs = 0, r = res; r; r = r->ai_next, maxs++)
3354                     ;
3355           socks = malloc((maxs + 1) * sizeof(int));
3356           if (!socks) {
3357                     freeaddrinfo(res);
3358                     syslog(LOG_ERR, "couldn't allocate memory for sockets");
3359                     return NULL;
3360           }
3361 
3362           *socks = 0;   /* num of sockets counter at start of array */
3363           s = socks + 1;
3364           for (r = res; r; r = r->ai_next) {
3365                     *s = socket(r->ai_family, r->ai_socktype, r->ai_protocol);
3366                     if (*s < 0) {
3367                               syslog(LOG_DEBUG, "control socket: %m");
3368                               continue;
3369                     }
3370                     if (setsockopt(*s, SOL_SOCKET, SO_REUSEADDR,
3371                         &on, sizeof(on)) < 0)
3372                               syslog(LOG_WARNING,
3373                                   "control setsockopt (SO_REUSEADDR): %m");
3374                     if (r->ai_family == AF_INET6) {
3375                               if (setsockopt(*s, IPPROTO_IPV6, IPV6_V6ONLY,
3376                                   &on, sizeof(on)) < 0)
3377                                         syslog(LOG_WARNING,
3378                                             "control setsockopt (IPV6_V6ONLY): %m");
3379                     }
3380                     if (bind(*s, r->ai_addr, r->ai_addrlen) < 0) {
3381                               syslog(LOG_DEBUG, "control bind: %m");
3382                               close(*s);
3383                               continue;
3384                     }
3385                     (*socks)++;
3386                     s++;
3387           }
3388 
3389           if (res)
3390                     freeaddrinfo(res);
3391 
3392           if (*socks == 0) {
3393                     syslog(LOG_ERR, "control socket: Couldn't bind to any socket");
3394                     free(socks);
3395                     return NULL;
3396           }
3397           return(socks);
3398 }
3399