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popen.c revision 1.31.4.1
      1 /*	$NetBSD: popen.c,v 1.31.4.1 2010/06/13 18:12:36 riz Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1999-2004 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  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *        This product includes software developed by the NetBSD
     21  *        Foundation, Inc. and its contributors.
     22  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23  *    contributors may be used to endorse or promote products derived
     24  *    from this software without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36  * POSSIBILITY OF SUCH DAMAGE.
     37  */
     38 
     39 /*
     40  * Copyright (c) 1988, 1993, 1994
     41  *	The Regents of the University of California.  All rights reserved.
     42  *
     43  * This code is derived from software written by Ken Arnold and
     44  * published in UNIX Review, Vol. 6, No. 8.
     45  *
     46  * Redistribution and use in source and binary forms, with or without
     47  * modification, are permitted provided that the following conditions
     48  * are met:
     49  * 1. Redistributions of source code must retain the above copyright
     50  *    notice, this list of conditions and the following disclaimer.
     51  * 2. Redistributions in binary form must reproduce the above copyright
     52  *    notice, this list of conditions and the following disclaimer in the
     53  *    documentation and/or other materials provided with the distribution.
     54  * 3. Neither the name of the University nor the names of its contributors
     55  *    may be used to endorse or promote products derived from this software
     56  *    without specific prior written permission.
     57  *
     58  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     59  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     60  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     61  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     62  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     63  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     64  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     65  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     66  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     67  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     68  * SUCH DAMAGE.
     69  *
     70  */
     71 
     72 #include <sys/cdefs.h>
     73 #ifndef lint
     74 #if 0
     75 static char sccsid[] = "@(#)popen.c	8.3 (Berkeley) 4/6/94";
     76 #else
     77 __RCSID("$NetBSD: popen.c,v 1.31.4.1 2010/06/13 18:12:36 riz Exp $");
     78 #endif
     79 #endif /* not lint */
     80 
     81 #include <sys/types.h>
     82 #include <sys/param.h>
     83 #include <sys/wait.h>
     84 
     85 #include <errno.h>
     86 #include <glob.h>
     87 #include <signal.h>
     88 #include <stdio.h>
     89 #include <stdlib.h>
     90 #include <string.h>
     91 #include <stringlist.h>
     92 #include <syslog.h>
     93 #include <unistd.h>
     94 
     95 #ifdef KERBEROS5
     96 #include <krb5/krb5.h>
     97 #endif
     98 
     99 #include "extern.h"
    100 
    101 #define INCR	100
    102 /*
    103  * Special version of popen which avoids call to shell.  This ensures no-one
    104  * may create a pipe to a hidden program as a side effect of a list or dir
    105  * command.
    106  * If stderrfd != -1, then send stderr of a read command there,
    107  * otherwise close stderr.
    108  */
    109 static int *pids;
    110 static int fds;
    111 
    112 extern int ls_main(int, char *[]);
    113 
    114 FILE *
    115 ftpd_popen(char *argv[], const char *ptype, int stderrfd)
    116 {
    117 	FILE *iop;
    118 	int argc, pdes[2], pid, isls;
    119 	char **pop;
    120 	StringList *sl;
    121 
    122 	iop = NULL;
    123 	isls = 0;
    124 	if ((*ptype != 'r' && *ptype != 'w') || ptype[1])
    125 		return (NULL);
    126 
    127 	if (!pids) {
    128 		if ((fds = getdtablesize()) <= 0)
    129 			return (NULL);
    130 		if ((pids = (int *)malloc((u_int)(fds * sizeof(int)))) == NULL)
    131 			return (NULL);
    132 		memset(pids, 0, fds * sizeof(int));
    133 	}
    134 	if (pipe(pdes) < 0)
    135 		return (NULL);
    136 
    137 	if ((sl = sl_init()) == NULL)
    138 		goto pfree;
    139 
    140 					/* glob each piece */
    141 	if (sl_add(sl, ftpd_strdup(argv[0])) == -1)
    142 		goto pfree;
    143 	for (argc = 1; argv[argc]; argc++) {
    144 		glob_t gl;
    145 		int flags = GLOB_BRACE|GLOB_NOCHECK|GLOB_TILDE|GLOB_LIMIT;
    146 
    147 		memset(&gl, 0, sizeof(gl));
    148 		if (glob(argv[argc], flags, NULL, &gl)
    149 		    || gl.gl_pathv == NULL)  {
    150 			if (sl_add(sl, ftpd_strdup(argv[argc])) == -1) {
    151 				globfree(&gl);
    152 				goto pfree;
    153 			}
    154 		} else {
    155 			for (pop = gl.gl_pathv; *pop; pop++) {
    156 				if (sl_add(sl, ftpd_strdup(*pop)) == -1) {
    157 					globfree(&gl);
    158 					goto pfree;
    159 				}
    160 			}
    161 		}
    162 		globfree(&gl);
    163 	}
    164 	if (sl_add(sl, NULL) == -1)
    165 		goto pfree;
    166 
    167 #ifndef NO_INTERNAL_LS
    168 	isls = (strcmp(sl->sl_str[0], INTERNAL_LS) == 0);
    169 #endif
    170 
    171 	pid = isls ? fork() : vfork();
    172 	switch (pid) {
    173 	case -1:			/* error */
    174 		(void)close(pdes[0]);
    175 		(void)close(pdes[1]);
    176 		goto pfree;
    177 		/* NOTREACHED */
    178 	case 0:				/* child */
    179 		if (*ptype == 'r') {
    180 			if (pdes[1] != STDOUT_FILENO) {
    181 				dup2(pdes[1], STDOUT_FILENO);
    182 				(void)close(pdes[1]);
    183 			}
    184 			if (stderrfd == -1)
    185 				(void)close(STDERR_FILENO);
    186 			else
    187 				dup2(stderrfd, STDERR_FILENO);
    188 			(void)close(pdes[0]);
    189 		} else {
    190 			if (pdes[0] != STDIN_FILENO) {
    191 				dup2(pdes[0], STDIN_FILENO);
    192 				(void)close(pdes[0]);
    193 			}
    194 			(void)close(pdes[1]);
    195 		}
    196 #ifndef NO_INTERNAL_LS
    197 		if (isls) {	/* use internal ls */
    198 			optreset = optind = optopt = 1;
    199 			closelog();
    200 			exit(ls_main(sl->sl_cur - 1, sl->sl_str));
    201 		}
    202 #endif
    203 
    204 		execv(sl->sl_str[0], sl->sl_str);
    205 		_exit(1);
    206 	}
    207 	/* parent; assume fdopen can't fail...  */
    208 	if (*ptype == 'r') {
    209 		iop = fdopen(pdes[0], ptype);
    210 		(void)close(pdes[1]);
    211 	} else {
    212 		iop = fdopen(pdes[1], ptype);
    213 		(void)close(pdes[0]);
    214 	}
    215 	pids[fileno(iop)] = pid;
    216 
    217  pfree:
    218 	if (sl)
    219 		sl_free(sl, 1);
    220 	return (iop);
    221 }
    222 
    223 int
    224 ftpd_pclose(FILE *iop)
    225 {
    226 	int fdes, status;
    227 	pid_t pid;
    228 	sigset_t nsigset, osigset;
    229 
    230 	/*
    231 	 * pclose returns -1 if stream is not associated with a
    232 	 * `popened' command, or, if already `pclosed'.
    233 	 */
    234 	if (pids == 0 || pids[fdes = fileno(iop)] == 0)
    235 		return (-1);
    236 	(void)fclose(iop);
    237 	sigemptyset(&nsigset);
    238 	sigaddset(&nsigset, SIGINT);
    239 	sigaddset(&nsigset, SIGQUIT);
    240 	sigaddset(&nsigset, SIGHUP);
    241 	sigprocmask(SIG_BLOCK, &nsigset, &osigset);
    242 	while ((pid = waitpid(pids[fdes], &status, 0)) < 0 && errno == EINTR)
    243 		continue;
    244 	sigprocmask(SIG_SETMASK, &osigset, NULL);
    245 	pids[fdes] = 0;
    246 	if (pid < 0)
    247 		return (pid);
    248 	if (WIFEXITED(status))
    249 		return (WEXITSTATUS(status));
    250 	return (1);
    251 }
    252