1 /*
2 * Copyright (c) 1983, 1993
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
30 #ifndef lint
31 static const char copyright[] =
32 "@(#) Copyright (c) 1983, 1993\n\
33 The Regents of the University of California. All rights reserved.\n";
34 #endif /* not lint */
35
36 #ifndef lint
37 #if 0
38 static char sccsid[] = "@(#)fingerd.c 8.1 (Berkeley) 6/4/93";
39 #endif
40 static const char rcsid[] =
41 "$FreeBSD$";
42 #endif /* not lint */
43
44 #include <sys/types.h>
45 #include <sys/param.h>
46 #include <sys/socket.h>
47 #include <netinet/in.h>
48 #include <netinet/tcp.h>
49 #include <arpa/inet.h>
50 #include <errno.h>
51
52 #include <unistd.h>
53 #include <syslog.h>
54 #include <libutil.h>
55 #include <netdb.h>
56 #include <stdio.h>
57 #include <stdlib.h>
58 #include <string.h>
59 #include "pathnames.h"
60
61 void logerr(const char *, ...) __printflike(1, 2) __dead2;
62
63 int
main(int argc,char * argv[])64 main(int argc, char *argv[])
65 {
66 FILE *fp;
67 int ch;
68 char *lp;
69 struct sockaddr_storage ss;
70 socklen_t sval;
71 int p[2], debug, kflag, logging, pflag, secure;
72 #define ENTRIES 50
73 char **ap, *av[ENTRIES + 1], **comp, line[1024], *prog;
74 char rhost[MAXHOSTNAMELEN];
75
76 prog = _PATH_FINGER;
77 debug = logging = kflag = pflag = secure = 0;
78 openlog("fingerd", LOG_PID | LOG_CONS, LOG_DAEMON);
79 opterr = 0;
80 while ((ch = getopt(argc, argv, "dklp:s")) != -1)
81 switch (ch) {
82 case 'd':
83 debug = 1;
84 break;
85 case 'k':
86 kflag = 1;
87 break;
88 case 'l':
89 logging = 1;
90 break;
91 case 'p':
92 prog = optarg;
93 pflag = 1;
94 break;
95 case 's':
96 secure = 1;
97 break;
98 case '?':
99 default:
100 logerr("illegal option -- %c", optopt);
101 }
102
103 /*
104 * Enable server-side Transaction TCP.
105 */
106 if (!debug) {
107 int one = 1;
108 if (setsockopt(STDOUT_FILENO, IPPROTO_TCP, TCP_NOPUSH, &one,
109 sizeof one) < 0) {
110 logerr("setsockopt(TCP_NOPUSH) failed: %m");
111 }
112 }
113
114 if (!fgets(line, sizeof(line), stdin))
115 exit(1);
116
117 if (!debug && (logging || pflag)) {
118 sval = sizeof(ss);
119 if (getpeername(0, (struct sockaddr *)&ss, &sval) < 0)
120 logerr("getpeername: %s", strerror(errno));
121 realhostname_sa(rhost, sizeof rhost - 1,
122 (struct sockaddr *)&ss, sval);
123 rhost[sizeof(rhost) - 1] = '\0';
124 if (pflag)
125 setenv("FINGERD_REMOTE_HOST", rhost, 1);
126 }
127
128 if (logging) {
129 char *t;
130 char *end;
131
132 end = memchr(line, 0, sizeof(line));
133 if (end == NULL) {
134 if ((t = malloc(sizeof(line) + 1)) == NULL)
135 logerr("malloc: %s", strerror(errno));
136 memcpy(t, line, sizeof(line));
137 t[sizeof(line)] = 0;
138 } else {
139 if ((t = strdup(line)) == NULL)
140 logerr("strdup: %s", strerror(errno));
141 }
142 for (end = t; *end; end++)
143 if (*end == '\n' || *end == '\r')
144 *end = ' ';
145 syslog(LOG_NOTICE, "query from %s: `%s'", rhost, t);
146 }
147
148 comp = &av[2];
149 av[3] = "--";
150 if (kflag)
151 *comp-- = "-k";
152 for (lp = line, ap = &av[4];;) {
153 *ap = strtok(lp, " \t\r\n");
154 if (!*ap) {
155 if (secure && ap == &av[4]) {
156 puts("must provide username\r\n");
157 exit(1);
158 }
159 break;
160 }
161 if (secure && strchr(*ap, '@')) {
162 puts("forwarding service denied\r\n");
163 exit(1);
164 }
165
166 /* RFC742: "/[Ww]" == "-l" */
167 if ((*ap)[0] == '/' && ((*ap)[1] == 'W' || (*ap)[1] == 'w')) {
168 *comp-- = "-l";
169 }
170 else if (++ap == av + ENTRIES) {
171 *ap = NULL;
172 break;
173 }
174 lp = NULL;
175 }
176
177 if ((lp = strrchr(prog, '/')) != NULL)
178 *comp = ++lp;
179 else
180 *comp = prog;
181 if (pipe(p) < 0)
182 logerr("pipe: %s", strerror(errno));
183
184 if (debug) {
185 fprintf(stderr, "%s", prog);
186 for (ap = comp; *ap != NULL; ++ap)
187 fprintf(stderr, " %s", *ap);
188 fprintf(stderr, "\n");
189 }
190
191 switch(vfork()) {
192 case 0:
193 (void)close(p[0]);
194 if (p[1] != STDOUT_FILENO) {
195 (void)dup2(p[1], STDOUT_FILENO);
196 (void)close(p[1]);
197 }
198 dup2(STDOUT_FILENO, STDERR_FILENO);
199
200 execv(prog, comp);
201 write(STDERR_FILENO, prog, strlen(prog));
202 #define MSG ": cannot execute\n"
203 write(STDERR_FILENO, MSG, strlen(MSG));
204 #undef MSG
205 _exit(1);
206 case -1:
207 logerr("fork: %s", strerror(errno));
208 }
209 (void)close(p[1]);
210 if (!(fp = fdopen(p[0], "r")))
211 logerr("fdopen: %s", strerror(errno));
212 while ((ch = getc(fp)) != EOF) {
213 if (ch == '\n')
214 putchar('\r');
215 putchar(ch);
216 }
217 exit(0);
218 }
219
220 #include <stdarg.h>
221
222 void
logerr(const char * fmt,...)223 logerr(const char *fmt, ...)
224 {
225 va_list ap;
226 va_start(ap, fmt);
227 (void)vsyslog(LOG_ERR, fmt, ap);
228 va_end(ap);
229 exit(1);
230 /* NOTREACHED */
231 }
232