1 /* $OpenBSD: popen.c,v 1.20 2003/12/10 22:57:12 deraadt Exp $ */
2 /* $NetBSD: popen.c,v 1.5 1995/04/11 02:45:00 cgd Exp $ */
3
4 /*
5 * Copyright (c) 1988, 1993, 1994
6 * The Regents of the University of California. All rights reserved.
7 *
8 * This code is derived from software written by Ken Arnold and
9 * published in UNIX Review, Vol. 6, No. 8.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 */
36
37 #ifndef lint
38 #if 0
39 static const char sccsid[] = "@(#)popen.c 8.3 (Berkeley) 4/6/94";
40 #else
41 static const char rcsid[] =
42 "$OpenBSD: popen.c,v 1.20 2003/12/10 22:57:12 deraadt Exp $";
43 #endif
44 #endif /* not lint */
45
46 #include <sys/types.h>
47 #include <sys/wait.h>
48
49 #include <errno.h>
50 #include <glob.h>
51 #include <signal.h>
52 #include <stdio.h>
53 #include <stdlib.h>
54 #include <string.h>
55 #include <syslog.h>
56 #include <unistd.h>
57
58 #include <netinet/in.h>
59 #include "extern.h"
60
61 /*
62 * Special version of popen which avoids call to shell. This ensures noone
63 * may create a pipe to a hidden program as a side effect of a list or dir
64 * command.
65 */
66 static pid_t *pids;
67 static int fds;
68
69 #define MAX_ARGV 100
70 #define MAX_GARGV 1000
71
72 FILE *
ftpd_popen(char * program,char * type)73 ftpd_popen(char *program, char *type)
74 {
75 char *cp;
76 FILE *iop;
77 int argc, gargc, pdes[2];
78 pid_t pid;
79 char **pop, *argv[MAX_ARGV], *gargv[MAX_GARGV];
80
81 if ((*type != 'r' && *type != 'w') || type[1])
82 return (NULL);
83
84 if (!pids) {
85 if ((fds = getdtablesize()) <= 0)
86 return (NULL);
87 if ((pids = (pid_t *)malloc((u_int)(fds * sizeof(pid_t)))) == NULL)
88 return (NULL);
89 memset(pids, 0, fds * sizeof(pid_t));
90 }
91 if (pipe(pdes) < 0)
92 return (NULL);
93
94 /* break up string into pieces */
95 for (argc = 0, cp = program;argc < MAX_ARGV-1; cp = NULL)
96 if (!(argv[argc++] = strtok(cp, " \t\n")))
97 break;
98 argv[MAX_ARGV-1] = NULL;
99
100 /* glob each piece */
101 gargv[0] = argv[0];
102 for (gargc = argc = 1; argv[argc]; argc++) {
103 glob_t gl;
104
105 memset(&gl, 0, sizeof(gl));
106 if (glob(argv[argc],
107 GLOB_BRACE|GLOB_NOCHECK|GLOB_QUOTE|GLOB_TILDE|GLOB_LIMIT,
108 NULL, &gl)) {
109 if (gargc < MAX_GARGV-1) {
110 gargv[gargc++] = strdup(argv[argc]);
111 if (gargv[gargc -1] == NULL)
112 fatal ("Out of memory.");
113 }
114
115 } else
116 for (pop = gl.gl_pathv; *pop && gargc < MAX_GARGV-1; pop++) {
117 gargv[gargc++] = strdup(*pop);
118 if (gargv[gargc - 1] == NULL)
119 fatal ("Out of memory.");
120 }
121 globfree(&gl);
122 }
123 gargv[gargc] = NULL;
124
125 iop = NULL;
126
127 switch (pid = fork()) {
128 case -1: /* error */
129 (void)close(pdes[0]);
130 (void)close(pdes[1]);
131 goto pfree;
132 /* NOTREACHED */
133 case 0: /* child */
134 if (*type == 'r') {
135 if (pdes[1] != STDOUT_FILENO) {
136 dup2(pdes[1], STDOUT_FILENO);
137 (void)close(pdes[1]);
138 }
139 dup2(STDOUT_FILENO, STDERR_FILENO); /* stderr too! */
140 (void)close(pdes[0]);
141 } else {
142 if (pdes[0] != STDIN_FILENO) {
143 dup2(pdes[0], STDIN_FILENO);
144 (void)close(pdes[0]);
145 }
146 (void)close(pdes[1]);
147 }
148 closelog();
149
150 if (strcmp(gargv[0], "/bin/ls") == 0) {
151 extern int optreset;
152 extern int ls_main(int, char **);
153
154 /* reset getopt for ls_main */
155 optreset = optind = 1;
156 exit(ls_main(gargc, gargv));
157 }
158
159 execv(gargv[0], gargv);
160 _exit(1);
161 }
162 /* parent; assume fdopen can't fail... */
163 if (*type == 'r') {
164 iop = fdopen(pdes[0], type);
165 (void)close(pdes[1]);
166 } else {
167 iop = fdopen(pdes[1], type);
168 (void)close(pdes[0]);
169 }
170 pids[fileno(iop)] = pid;
171
172 pfree: for (argc = 1; gargv[argc] != NULL; argc++)
173 free(gargv[argc]);
174
175 return (iop);
176 }
177
178 int
ftpd_pclose(FILE * iop)179 ftpd_pclose(FILE *iop)
180 {
181 int fdes, status;
182 pid_t pid;
183 sigset_t sigset, osigset;
184
185 /*
186 * pclose returns -1 if stream is not associated with a
187 * `popened' command, or, if already `pclosed'.
188 */
189 if (pids == 0 || pids[fdes = fileno(iop)] == 0)
190 return (-1);
191 (void)fclose(iop);
192 sigemptyset(&sigset);
193 sigaddset(&sigset, SIGINT);
194 sigaddset(&sigset, SIGQUIT);
195 sigaddset(&sigset, SIGHUP);
196 sigprocmask(SIG_BLOCK, &sigset, &osigset);
197 while ((pid = waitpid(pids[fdes], &status, 0)) < 0 && errno == EINTR)
198 continue;
199 sigprocmask(SIG_SETMASK, &osigset, NULL);
200 pids[fdes] = 0;
201 if (pid < 0)
202 return (-1);
203 if (WIFEXITED(status))
204 return (WEXITSTATUS(status));
205 return (1);
206 }
207