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popen.c revision 1.1.1.2 
      1 /*
      2  * Copyright (c) 1988, 1993, 1994
      3  *	The Regents of the University of California.  All rights reserved.
      4  *
      5  * This code is derived from software written by Ken Arnold and
      6  * published in UNIX Review, Vol. 6, No. 8.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  * 1. Redistributions of source code must retain the above copyright
     12  *    notice, this list of conditions and the following disclaimer.
     13  * 2. Redistributions in binary form must reproduce the above copyright
     14  *    notice, this list of conditions and the following disclaimer in the
     15  *    documentation and/or other materials provided with the distribution.
     16  * 3. All advertising materials mentioning features or use of this software
     17  *    must display the following acknowledgement:
     18  *	This product includes software developed by the University of
     19  *	California, Berkeley and its contributors.
     20  * 4. Neither the name of the University nor the names of its contributors
     21  *    may be used to endorse or promote products derived from this software
     22  *    without specific prior written permission.
     23  *
     24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     34  * SUCH DAMAGE.
     35  *
     36  */
     37 
     38 #ifndef lint
     39 static char sccsid[] = "@(#)popen.c	8.3 (Berkeley) 4/6/94";
     40 #endif /* not lint */
     41 
     42 #include <sys/types.h>
     43 #include <sys/wait.h>
     44 
     45 #include <errno.h>
     46 #include <glob.h>
     47 #include <signal.h>
     48 #include <stdio.h>
     49 #include <stdlib.h>
     50 #include <string.h>
     51 #include <unistd.h>
     52 
     53 #include "extern.h"
     54 
     55 /*
     56  * Special version of popen which avoids call to shell.  This ensures noone
     57  * may create a pipe to a hidden program as a side effect of a list or dir
     58  * command.
     59  */
     60 static int *pids;
     61 static int fds;
     62 
     63 FILE *
     64 ftpd_popen(program, type)
     65 	char *program, *type;
     66 {
     67 	char *cp;
     68 	FILE *iop;
     69 	int argc, gargc, pdes[2], pid;
     70 	char **pop, *argv[100], *gargv[1000];
     71 
     72 	if (*type != 'r' && *type != 'w' || type[1])
     73 		return (NULL);
     74 
     75 	if (!pids) {
     76 		if ((fds = getdtablesize()) <= 0)
     77 			return (NULL);
     78 		if ((pids = (int *)malloc((u_int)(fds * sizeof(int)))) == NULL)
     79 			return (NULL);
     80 		memset(pids, 0, fds * sizeof(int));
     81 	}
     82 	if (pipe(pdes) < 0)
     83 		return (NULL);
     84 
     85 	/* break up string into pieces */
     86 	for (argc = 0, cp = program;; cp = NULL)
     87 		if (!(argv[argc++] = strtok(cp, " \t\n")))
     88 			break;
     89 
     90 	/* glob each piece */
     91 	gargv[0] = argv[0];
     92 	for (gargc = argc = 1; argv[argc]; argc++) {
     93 		glob_t gl;
     94 		int flags = GLOB_BRACE|GLOB_NOCHECK|GLOB_QUOTE|GLOB_TILDE;
     95 
     96 		memset(&gl, 0, sizeof(gl));
     97 		if (glob(argv[argc], flags, NULL, &gl))
     98 			gargv[gargc++] = strdup(argv[argc]);
     99 		else
    100 			for (pop = gl.gl_pathv; *pop; pop++)
    101 				gargv[gargc++] = strdup(*pop);
    102 		globfree(&gl);
    103 	}
    104 	gargv[gargc] = NULL;
    105 
    106 	iop = NULL;
    107 	switch(pid = vfork()) {
    108 	case -1:			/* error */
    109 		(void)close(pdes[0]);
    110 		(void)close(pdes[1]);
    111 		goto pfree;
    112 		/* NOTREACHED */
    113 	case 0:				/* child */
    114 		if (*type == 'r') {
    115 			if (pdes[1] != STDOUT_FILENO) {
    116 				dup2(pdes[1], STDOUT_FILENO);
    117 				(void)close(pdes[1]);
    118 			}
    119 			dup2(STDOUT_FILENO, STDERR_FILENO); /* stderr too! */
    120 			(void)close(pdes[0]);
    121 		} else {
    122 			if (pdes[0] != STDIN_FILENO) {
    123 				dup2(pdes[0], STDIN_FILENO);
    124 				(void)close(pdes[0]);
    125 			}
    126 			(void)close(pdes[1]);
    127 		}
    128 		execv(gargv[0], gargv);
    129 		_exit(1);
    130 	}
    131 	/* parent; assume fdopen can't fail...  */
    132 	if (*type == 'r') {
    133 		iop = fdopen(pdes[0], type);
    134 		(void)close(pdes[1]);
    135 	} else {
    136 		iop = fdopen(pdes[1], type);
    137 		(void)close(pdes[0]);
    138 	}
    139 	pids[fileno(iop)] = pid;
    140 
    141 pfree:	for (argc = 1; gargv[argc] != NULL; argc++)
    142 		free(gargv[argc]);
    143 
    144 	return (iop);
    145 }
    146 
    147 int
    148 ftpd_pclose(iop)
    149 	FILE *iop;
    150 {
    151 	int fdes, omask, status;
    152 	pid_t pid;
    153 
    154 	/*
    155 	 * pclose returns -1 if stream is not associated with a
    156 	 * `popened' command, or, if already `pclosed'.
    157 	 */
    158 	if (pids == 0 || pids[fdes = fileno(iop)] == 0)
    159 		return (-1);
    160 	(void)fclose(iop);
    161 	omask = sigblock(sigmask(SIGINT)|sigmask(SIGQUIT)|sigmask(SIGHUP));
    162 	while ((pid = waitpid(pids[fdes], &status, 0)) < 0 && errno == EINTR)
    163 		continue;
    164 	(void)sigsetmask(omask);
    165 	pids[fdes] = 0;
    166 	if (pid < 0)
    167 		return (pid);
    168 	if (WIFEXITED(status))
    169 		return (WEXITSTATUS(status));
    170 	return (1);
    171 }
    172