popen.c revision 1.6
1/* $OpenBSD: popen.c,v 1.6 1996/10/25 23:37:01 imp Exp $ */ 2/* $NetBSD: popen.c,v 1.5 1995/04/11 02:45:00 cgd Exp $ */ 3 4/* 5 * Copyright (c) 1988, 1993, 1994 6 * The Regents of the University of California. All rights reserved. 7 * 8 * This code is derived from software written by Ken Arnold and 9 * published in UNIX Review, Vol. 6, No. 8. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the University of 22 * California, Berkeley and its contributors. 23 * 4. Neither the name of the University nor the names of its contributors 24 * may be used to endorse or promote products derived from this software 25 * without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 * 39 */ 40 41#ifndef lint 42#if 0 43static char sccsid[] = "@(#)popen.c 8.3 (Berkeley) 4/6/94"; 44#else 45static char rcsid[] = "$NetBSD: popen.c,v 1.5 1995/04/11 02:45:00 cgd Exp $"; 46#endif 47#endif /* not lint */ 48 49#include <sys/types.h> 50#include <sys/wait.h> 51 52#include <errno.h> 53#include <glob.h> 54#include <signal.h> 55#include <stdio.h> 56#include <stdlib.h> 57#include <string.h> 58#include <syslog.h> 59#include <unistd.h> 60 61#include "extern.h" 62 63/* 64 * Special version of popen which avoids call to shell. This ensures noone 65 * may create a pipe to a hidden program as a side effect of a list or dir 66 * command. 67 */ 68static int *pids; 69static int fds; 70 71#define MAX_ARGV 100 72#define MAX_GARGV 1000 73 74FILE * 75ftpd_popen(program, type) 76 char *program, *type; 77{ 78 char *cp; 79 FILE *iop; 80 int argc, gargc, pdes[2], pid; 81 char **pop, *argv[MAX_ARGV], *gargv[MAX_GARGV]; 82 83 if (*type != 'r' && *type != 'w' || type[1]) 84 return (NULL); 85 86 if (!pids) { 87 if ((fds = getdtablesize()) <= 0) 88 return (NULL); 89 if ((pids = (int *)malloc((u_int)(fds * sizeof(int)))) == NULL) 90 return (NULL); 91 memset(pids, 0, fds * sizeof(int)); 92 } 93 if (pipe(pdes) < 0) 94 return (NULL); 95 96 /* break up string into pieces */ 97 for (argc = 0, cp = program;argc < MAX_ARGV - 1; cp = NULL) 98 if (!(argv[argc++] = strtok(cp, " \t\n"))) 99 break; 100 argv[ MAX_ARGV - 1 ] = NULL; 101 102 /* glob each piece */ 103 gargv[0] = argv[0]; 104 for (gargc = argc = 1; argv[argc]; argc++) { 105 glob_t gl; 106 int flags = GLOB_BRACE|GLOB_NOCHECK|GLOB_QUOTE|GLOB_TILDE; 107 108 memset(&gl, 0, sizeof(gl)); 109 if (glob(argv[argc], flags, NULL, &gl)) { 110 if (gargc < MAX_GARGV - 1) 111 gargv[gargc++] = strdup(argv[argc]); 112 } else 113 for (pop = gl.gl_pathv; *pop && gargc < MAX_GARGV - 1; pop++) 114 gargv[gargc++] = strdup(*pop); 115 globfree(&gl); 116 } 117 gargv[gargc] = NULL; 118 119 iop = NULL; 120 switch(pid = vfork()) { 121 case -1: /* error */ 122 (void)close(pdes[0]); 123 (void)close(pdes[1]); 124 goto pfree; 125 /* NOTREACHED */ 126 case 0: /* child */ 127 if (*type == 'r') { 128 if (pdes[1] != STDOUT_FILENO) { 129 dup2(pdes[1], STDOUT_FILENO); 130 (void)close(pdes[1]); 131 } 132 dup2(STDOUT_FILENO, STDERR_FILENO); /* stderr too! */ 133 (void)close(pdes[0]); 134 } else { 135 if (pdes[0] != STDIN_FILENO) { 136 dup2(pdes[0], STDIN_FILENO); 137 (void)close(pdes[0]); 138 } 139 (void)close(pdes[1]); 140 } 141 closelog(); 142 143 execv(gargv[0], gargv); 144 _exit(1); 145 } 146 /* parent; assume fdopen can't fail... */ 147 if (*type == 'r') { 148 iop = fdopen(pdes[0], type); 149 (void)close(pdes[1]); 150 } else { 151 iop = fdopen(pdes[1], type); 152 (void)close(pdes[0]); 153 } 154 pids[fileno(iop)] = pid; 155 156pfree: for (argc = 1; gargv[argc] != NULL; argc++) 157 free(gargv[argc]); 158 159 return (iop); 160} 161 162int 163ftpd_pclose(iop) 164 FILE *iop; 165{ 166 int fdes, omask, status; 167 pid_t pid; 168 sigset_t sigset, osigset; 169 170 /* 171 * pclose returns -1 if stream is not associated with a 172 * `popened' command, or, if already `pclosed'. 173 */ 174 if (pids == 0 || pids[fdes = fileno(iop)] == 0) 175 return (-1); 176 (void)fclose(iop); 177 sigemptyset(&sigset); 178 sigaddset(&sigset, SIGINT); 179 sigaddset(&sigset, SIGQUIT); 180 sigaddset(&sigset, SIGHUP); 181 sigprocmask(SIG_BLOCK, &sigset, &osigset); 182 while ((pid = waitpid(pids[fdes], &status, 0)) < 0 && errno == EINTR) 183 continue; 184 sigprocmask(SIG_SETMASK, &osigset, NULL); 185 pids[fdes] = 0; 186 if (pid < 0) 187 return (pid); 188 if (WIFEXITED(status)) 189 return (WEXITSTATUS(status)); 190 return (1); 191} 192