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      1 /*	$NetBSD: popen.c,v 1.38 2016/03/17 00:17:58 christos 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 1.38 2016/03/17 00:17:58 christos 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 * volatile 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 		    || gl.gl_pathv == NULL)  {
    144 			if (sl_add(sl, ftpd_strdup(argv[argc])) == -1) {
    145 				globfree(&gl);
    146 				goto pfree;
    147 			}
    148 		} else {
    149 			for (pop = gl.gl_pathv; *pop; pop++) {
    150 				if (sl_add(sl, ftpd_strdup(*pop)) == -1) {
    151 					globfree(&gl);
    152 					goto pfree;
    153 				}
    154 			}
    155 		}
    156 		globfree(&gl);
    157 	}
    158 	if (sl_add(sl, NULL) == -1)
    159 		goto pfree;
    160 
    161 #ifndef NO_INTERNAL_LS
    162 	isls = (strcmp(sl->sl_str[0], INTERNAL_LS) == 0);
    163 #endif
    164 
    165 	pid = isls ? fork() : vfork();
    166 	switch (pid) {
    167 	case -1:			/* error */
    168 		(void)close(pdes[0]);
    169 		(void)close(pdes[1]);
    170 		goto pfree;
    171 		/* NOTREACHED */
    172 	case 0:				/* child */
    173 		if (*ptype == 'r') {
    174 			if (pdes[1] != STDOUT_FILENO) {
    175 				dup2(pdes[1], STDOUT_FILENO);
    176 				(void)close(pdes[1]);
    177 			}
    178 			if (stderrfd == -1)
    179 				(void)close(STDERR_FILENO);
    180 			else
    181 				dup2(stderrfd, STDERR_FILENO);
    182 			(void)close(pdes[0]);
    183 		} else {
    184 			if (pdes[0] != STDIN_FILENO) {
    185 				dup2(pdes[0], STDIN_FILENO);
    186 				(void)close(pdes[0]);
    187 			}
    188 			(void)close(pdes[1]);
    189 		}
    190 #ifndef NO_INTERNAL_LS
    191 		if (isls) {	/* use internal ls */
    192 			optreset = optind = optopt = 1;
    193 			closelog();
    194 			exit(ls_main(sl->sl_cur - 1, sl->sl_str));
    195 		}
    196 #endif
    197 
    198 		execv(sl->sl_str[0], sl->sl_str);
    199 		_exit(1);
    200 	}
    201 	/* parent; assume fdopen can't fail...  */
    202 	if (*ptype == 'r') {
    203 		iop = fdopen(pdes[0], ptype);
    204 		(void)close(pdes[1]);
    205 	} else {
    206 		iop = fdopen(pdes[1], ptype);
    207 		(void)close(pdes[0]);
    208 	}
    209 	pids[fileno(iop)] = pid;
    210 
    211  pfree:
    212 	if (sl)
    213 		sl_free(sl, 1);
    214 	return (iop);
    215 }
    216 
    217 int
    218 ftpd_pclose(FILE *iop)
    219 {
    220 	int fdes, status;
    221 	pid_t pid;
    222 	sigset_t nsigset, osigset;
    223 
    224 	/*
    225 	 * pclose returns -1 if stream is not associated with a
    226 	 * `popened' command, or, if already `pclosed'.
    227 	 */
    228 	if (pids == 0 || pids[fdes = fileno(iop)] == 0)
    229 		return (-1);
    230 	(void)fclose(iop);
    231 	sigemptyset(&nsigset);
    232 	sigaddset(&nsigset, SIGINT);
    233 	sigaddset(&nsigset, SIGQUIT);
    234 	sigaddset(&nsigset, SIGHUP);
    235 	sigprocmask(SIG_BLOCK, &nsigset, &osigset);
    236 	while ((pid = waitpid(pids[fdes], &status, 0)) < 0 && errno == EINTR)
    237 		continue;
    238 	sigprocmask(SIG_SETMASK, &osigset, NULL);
    239 	pids[fdes] = 0;
    240 	if (pid < 0)
    241 		return (pid);
    242 	if (WIFEXITED(status))
    243 		return (WEXITSTATUS(status));
    244 	return (1);
    245 }
    246