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popen.c revision 1.34.6.1
      1 /*	$NetBSD: popen.c,v 1.34.6.1 2009/05/13 19:18:37 jym Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1999-2009 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Luke Mewburn.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 /*
     33  * Copyright (c) 1988, 1993, 1994
     34  *	The Regents of the University of California.  All rights reserved.
     35  *
     36  * This code is derived from software written by Ken Arnold and
     37  * published in UNIX Review, Vol. 6, No. 8.
     38  *
     39  * Redistribution and use in source and binary forms, with or without
     40  * modification, are permitted provided that the following conditions
     41  * are met:
     42  * 1. Redistributions of source code must retain the above copyright
     43  *    notice, this list of conditions and the following disclaimer.
     44  * 2. Redistributions in binary form must reproduce the above copyright
     45  *    notice, this list of conditions and the following disclaimer in the
     46  *    documentation and/or other materials provided with the distribution.
     47  * 3. Neither the name of the University nor the names of its contributors
     48  *    may be used to endorse or promote products derived from this software
     49  *    without specific prior written permission.
     50  *
     51  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     52  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     53  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     54  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     55  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     56  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     57  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     58  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     59  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     60  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     61  * SUCH DAMAGE.
     62  *
     63  */
     64 
     65 #include <sys/cdefs.h>
     66 #ifndef lint
     67 #if 0
     68 static char sccsid[] = "@(#)popen.c	8.3 (Berkeley) 4/6/94";
     69 #else
     70 __RCSID("$NetBSD: popen.c,v 1.34.6.1 2009/05/13 19:18:37 jym Exp $");
     71 #endif
     72 #endif /* not lint */
     73 
     74 #include <sys/types.h>
     75 #include <sys/param.h>
     76 #include <sys/wait.h>
     77 
     78 #include <errno.h>
     79 #include <glob.h>
     80 #include <signal.h>
     81 #include <stdio.h>
     82 #include <stdlib.h>
     83 #include <string.h>
     84 #include <stringlist.h>
     85 #include <syslog.h>
     86 #include <unistd.h>
     87 
     88 #ifdef KERBEROS5
     89 #include <krb5/krb5.h>
     90 #endif
     91 
     92 #include "extern.h"
     93 
     94 #define INCR	100
     95 /*
     96  * Special version of popen which avoids call to shell.  This ensures no-one
     97  * may create a pipe to a hidden program as a side effect of a list or dir
     98  * command.
     99  * If stderrfd != -1, then send stderr of a read command there,
    100  * otherwise close stderr.
    101  */
    102 static int *pids;
    103 static int fds;
    104 
    105 extern int ls_main(int, char *[]);
    106 
    107 FILE *
    108 ftpd_popen(const char *argv[], const char *ptype, int stderrfd)
    109 {
    110 	FILE *iop;
    111 	int argc, pdes[2], pid;
    112 	volatile int isls;
    113 	char **pop;
    114 	StringList *sl;
    115 
    116 	iop = NULL;
    117 	isls = 0;
    118 	if ((*ptype != 'r' && *ptype != 'w') || ptype[1])
    119 		return (NULL);
    120 
    121 	if (!pids) {
    122 		if ((fds = getdtablesize()) <= 0)
    123 			return (NULL);
    124 		if ((pids = (int *)malloc((unsigned int)(fds * sizeof(int)))) == NULL)
    125 			return (NULL);
    126 		memset(pids, 0, fds * sizeof(int));
    127 	}
    128 	if (pipe(pdes) < 0)
    129 		return (NULL);
    130 
    131 	if ((sl = sl_init()) == NULL)
    132 		goto pfree;
    133 
    134 					/* glob each piece */
    135 	if (sl_add(sl, ftpd_strdup(argv[0])) == -1)
    136 		goto pfree;
    137 	for (argc = 1; argv[argc]; argc++) {
    138 		glob_t gl;
    139 		int flags = GLOB_BRACE|GLOB_NOCHECK|GLOB_TILDE|GLOB_LIMIT;
    140 
    141 		memset(&gl, 0, sizeof(gl));
    142 		if (glob(argv[argc], flags, NULL, &gl)) {
    143 			if (sl_add(sl, ftpd_strdup(argv[argc])) == -1) {
    144 				globfree(&gl);
    145 				goto pfree;
    146 			}
    147 		} else {
    148 			for (pop = gl.gl_pathv; *pop; pop++) {
    149 				if (sl_add(sl, ftpd_strdup(*pop)) == -1) {
    150 					globfree(&gl);
    151 					goto pfree;
    152 				}
    153 			}
    154 		}
    155 		globfree(&gl);
    156 	}
    157 	if (sl_add(sl, NULL) == -1)
    158 		goto pfree;
    159 
    160 #ifndef NO_INTERNAL_LS
    161 	isls = (strcmp(sl->sl_str[0], INTERNAL_LS) == 0);
    162 #endif
    163 
    164 	pid = isls ? fork() : vfork();
    165 	switch (pid) {
    166 	case -1:			/* error */
    167 		(void)close(pdes[0]);
    168 		(void)close(pdes[1]);
    169 		goto pfree;
    170 		/* NOTREACHED */
    171 	case 0:				/* child */
    172 		if (*ptype == 'r') {
    173 			if (pdes[1] != STDOUT_FILENO) {
    174 				dup2(pdes[1], STDOUT_FILENO);
    175 				(void)close(pdes[1]);
    176 			}
    177 			if (stderrfd == -1)
    178 				(void)close(STDERR_FILENO);
    179 			else
    180 				dup2(stderrfd, STDERR_FILENO);
    181 			(void)close(pdes[0]);
    182 		} else {
    183 			if (pdes[0] != STDIN_FILENO) {
    184 				dup2(pdes[0], STDIN_FILENO);
    185 				(void)close(pdes[0]);
    186 			}
    187 			(void)close(pdes[1]);
    188 		}
    189 #ifndef NO_INTERNAL_LS
    190 		if (isls) {	/* use internal ls */
    191 			optreset = optind = optopt = 1;
    192 			closelog();
    193 			exit(ls_main(sl->sl_cur - 1, sl->sl_str));
    194 		}
    195 #endif
    196 
    197 		execv(sl->sl_str[0], sl->sl_str);
    198 		_exit(1);
    199 	}
    200 	/* parent; assume fdopen can't fail...  */
    201 	if (*ptype == 'r') {
    202 		iop = fdopen(pdes[0], ptype);
    203 		(void)close(pdes[1]);
    204 	} else {
    205 		iop = fdopen(pdes[1], ptype);
    206 		(void)close(pdes[0]);
    207 	}
    208 	pids[fileno(iop)] = pid;
    209 
    210  pfree:
    211 	if (sl)
    212 		sl_free(sl, 1);
    213 	return (iop);
    214 }
    215 
    216 int
    217 ftpd_pclose(FILE *iop)
    218 {
    219 	int fdes, status;
    220 	pid_t pid;
    221 	sigset_t nsigset, osigset;
    222 
    223 	/*
    224 	 * pclose returns -1 if stream is not associated with a
    225 	 * `popened' command, or, if already `pclosed'.
    226 	 */
    227 	if (pids == 0 || pids[fdes = fileno(iop)] == 0)
    228 		return (-1);
    229 	(void)fclose(iop);
    230 	sigemptyset(&nsigset);
    231 	sigaddset(&nsigset, SIGINT);
    232 	sigaddset(&nsigset, SIGQUIT);
    233 	sigaddset(&nsigset, SIGHUP);
    234 	sigprocmask(SIG_BLOCK, &nsigset, &osigset);
    235 	while ((pid = waitpid(pids[fdes], &status, 0)) < 0 && errno == EINTR)
    236 		continue;
    237 	sigprocmask(SIG_SETMASK, &osigset, NULL);
    238 	pids[fdes] = 0;
    239 	if (pid < 0)
    240 		return (pid);
    241 	if (WIFEXITED(status))
    242 		return (WEXITSTATUS(status));
    243 	return (1);
    244 }
    245