popen.c revision 59118 
1/* popen.c: A "safe" pipe open routine.
2
3%%% portions-copyright-cmetz-96
4Portions of this software are Copyright 1996-1998 by Craig Metz, All Rights
5Reserved. The Inner Net License Version 2 applies to these portions of
6the software.
7You should have received a copy of the license with this software. If
8you didn't get a copy, you may request one from <license@inner.net>.
9
10Portions of this software are Copyright 1995 by Randall Atkinson and Dan
11McDonald, All Rights Reserved. All Rights under this copyright are assigned
12to the U.S. Naval Research Laboratory (NRL). The NRL Copyright Notice and
13License Agreement applies to this software.
14
15	History:
16
17	Modified by cmetz for OPIE 2.31. Merged in some 4.4BSD-Lite fixes.
18	Modified by cmetz for OPIE 2.2. Use FUNCTION declaration et al.
19                Removed useless string. ifdef around some headers.
20        Modified at NRL for OPIE 2.1. Optimized for only one pipe at a time.
21                Added minimal version of sigprocmask(). Moved some pid_t
22		dancing to the config headers.
23	Modified at NRL for OPIE 2.0.
24	Originally from BSD.
25
26*/
27/*
28 * Copyright (c) 1988, 1993, 1994
29 *     The Regents of the University of California.  All rights reserved.
30 *
31 * This code is derived from software written by Ken Arnold and
32 * published in UNIX Review, Vol. 6, No. 8.
33 *
34 * Redistribution and use in source and binary forms, with or without
35 * modification, are permitted provided that the following conditions
36 * are met:
37 * 1. Redistributions of source code must retain the above copyright
38 *    notice, this list of conditions and the following disclaimer.
39 * 2. Redistributions in binary form must reproduce the above copyright
40 *    notice, this list of conditions and the following disclaimer in the
41 *    documentation and/or other materials provided with the distribution.
42 * 3. All advertising materials mentioning features or use of this software
43 *    must display the following acknowledgement:
44 *      This product includes software developed by the University of
45 *      California, Berkeley and its contributors.
46 * 4. Neither the name of the University nor the names of its contributors
47 *    may be used to endorse or promote products derived from this software
48 *    without specific prior written permission.
49 *
50 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
51 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
52 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
53 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
54 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
55 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
56 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
57 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
58 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
59 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
60 * SUCH DAMAGE.
61 *
62 */
63
64#include "opie_cfg.h"
65
66#include <sys/types.h>
67#include <sys/wait.h>
68#if HAVE_SIGNAL_H
69#include <signal.h>
70#endif /* HAVE_SIGNAL_H */
71#if HAVE_SYS_SIGNAL_H
72#include <sys/signal.h>
73#endif /* HAVE_SYS_SIGNAL_H */
74#if HAVE_UNISTD_H
75#include <unistd.h>
76#endif /* HAVE_UNISTD_H */
77#include <stdio.h>
78#if HAVE_STDLIB_H
79#include <stdlib.h>
80#endif /* HAVE_STDLIB_H */
81#if HAVE_STRING_H
82#include <string.h>
83#endif /* HAVE_STRING_H */
84
85#include "opie.h"
86
87char **ftpglob __P((register char *));
88char **copyblk __P((char **));
89VOIDRET blkfree __P((char **));
90
91/*
92 * Special version of popen which avoids call to shell.  This ensures noone
93 * may create a pipe to a hidden program as a side effect of a list or dir
94 * command.
95 */
96static pid_t child_pid = -1;
97static int pipe_fd;
98
99extern char **environ;
100
101FILE *ftpd_popen FUNCTION((program, type), char *program AND char *type)
102{
103  char *cp;
104  FILE *iop;
105  int argc, gargc, pdes[2];
106  char **pop, *argv[100], *gargv[1000], *vv[2];
107
108  if ((*type != 'r' && *type != 'w') || type[1])
109    return (NULL);
110
111  if (pipe(pdes) < 0)
112    return (NULL);
113
114  /* break up string into pieces */
115  for (argc = 0, cp = program;; cp = NULL)
116    if (!(argv[argc++] = strtok(cp, " \t\n")))
117      break;
118
119  /* glob each piece */
120  gargv[0] = argv[0];
121  for (gargc = argc = 1; argv[argc]; argc++) {
122    if (!(pop = (char **) ftpglob(argv[argc]))) {
123      /* globbing failed */
124      vv[0] = argv[argc];
125      vv[1] = NULL;
126      pop = (char **) copyblk(vv);
127    }
128    argv[argc] = (char *) pop;	/* save to free later */
129    while (*pop && gargc < 1000)
130      gargv[gargc++] = *pop++;
131  }
132  gargv[gargc] = NULL;
133
134  iop = NULL;
135  switch (child_pid = fork()) {
136  case -1:	/* error */
137    close(pdes[0]);
138    close(pdes[1]);
139    goto pfree;
140    /* NOTREACHED */
141  case 0:	/* child */
142    if (*type == 'r') {
143      if (pdes[1] != 1) {
144	dup2(pdes[1], 1);
145	dup2(pdes[1], 2);	/* stderr, too! */
146	close(pdes[1]);
147      }
148      close(pdes[0]);
149    } else {
150      if (pdes[0] != 0) {
151	dup2(pdes[0], 0);
152	close(pdes[0]);
153      }
154      close(pdes[1]);
155    }
156    environ = NULL;
157    execv(gargv[0], gargv);
158    _exit(1);
159  }
160
161  /* parent; assume fdopen can't fail...  */
162  if (*type == 'r') {
163    iop = fdopen(pipe_fd = pdes[0], type);
164    close(pdes[1]);
165  } else {
166    iop = fdopen(pipe_fd = pdes[1], type);
167    close(pdes[0]);
168  }
169
170pfree: for (argc = 1; argv[argc] != NULL; argc++) {
171    blkfree((char **) argv[argc]);
172    free((char *) argv[argc]);
173  }
174  return (iop);
175}
176
177int ftpd_pclose FUNCTION((iop), FILE *iop)
178{
179  int status;
180  pid_t pid;
181  sigset_t omask, mask;
182
183  sigemptyset(&mask);
184  sigaddset(&mask, SIGINT);
185  sigaddset(&mask, SIGQUIT);
186  sigaddset(&mask, SIGHUP);
187
188  /* pclose returns -1 if stream is not associated with a `popened' command,
189     or, if already `pclosed'. */
190  if ((child_pid < 0) || (fileno(iop) != pipe_fd))
191    return (-1);
192
193  fclose(iop);
194  sigprocmask(SIG_BLOCK, &mask, &omask);
195
196  while ((pid = wait(&status)) != child_pid && (pid != -1));
197  sigprocmask(SIG_SETMASK, &omask, NULL);
198
199  child_pid = -1;
200  pipe_fd = -1;
201
202#if defined(WEXITSTATUS) && defined(WIFEXITED)
203  if ((pid > 0) && WIFEXITED(status))
204    return WEXITSTATUS(status);
205
206  return -1;
207#else /* defined(WEXITSTATUS) && defined(WIFEXITED) */
208  return (pid == -1 ? -1 : status.w_status);
209#endif /* defined(WEXITSTATUS) && defined(WIFEXITED) */
210}
211