popen.c revision 1.18
1/* $OpenBSD: popen.c,v 1.18 2003/06/02 19:38:24 millert 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. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 */ 36 37#ifndef lint 38#if 0 39static const char sccsid[] = "@(#)popen.c 8.3 (Berkeley) 4/6/94"; 40#else 41static const char rcsid[] = 42 "$OpenBSD: popen.c,v 1.18 2003/06/02 19:38:24 millert Exp $"; 43#endif 44#endif /* not lint */ 45 46#include <sys/types.h> 47#include <sys/wait.h> 48 49#include <errno.h> 50#include <glob.h> 51#include <signal.h> 52#include <stdio.h> 53#include <stdlib.h> 54#include <string.h> 55#include <syslog.h> 56#include <unistd.h> 57 58#include <netinet/in.h> 59#include "extern.h" 60 61/* 62 * Special version of popen which avoids call to shell. This ensures noone 63 * may create a pipe to a hidden program as a side effect of a list or dir 64 * command. 65 */ 66static pid_t *pids; 67static int fds; 68 69#define MAX_ARGV 100 70#define MAX_GARGV 1000 71 72FILE * 73ftpd_popen(program, type) 74 char *program, *type; 75{ 76 char *cp; 77 FILE *iop; 78 int argc, gargc, pdes[2]; 79 pid_t pid; 80 char **pop, *argv[MAX_ARGV], *gargv[MAX_GARGV]; 81 82 if ((*type != 'r' && *type != 'w') || type[1]) 83 return (NULL); 84 85 if (!pids) { 86 if ((fds = getdtablesize()) <= 0) 87 return (NULL); 88 if ((pids = (pid_t *)malloc((u_int)(fds * sizeof(pid_t)))) == NULL) 89 return (NULL); 90 memset(pids, 0, fds * sizeof(pid_t)); 91 } 92 if (pipe(pdes) < 0) 93 return (NULL); 94 95 /* break up string into pieces */ 96 for (argc = 0, cp = program;argc < MAX_ARGV-1; cp = NULL) 97 if (!(argv[argc++] = strtok(cp, " \t\n"))) 98 break; 99 argv[MAX_ARGV-1] = NULL; 100 101 /* glob each piece */ 102 gargv[0] = argv[0]; 103 for (gargc = argc = 1; argv[argc]; argc++) { 104 glob_t gl; 105 106 memset(&gl, 0, sizeof(gl)); 107 if (glob(argv[argc], 108 GLOB_BRACE|GLOB_NOCHECK|GLOB_QUOTE|GLOB_TILDE|GLOB_LIMIT, 109 NULL, &gl)) { 110 if (gargc < MAX_GARGV-1) { 111 gargv[gargc++] = strdup(argv[argc]); 112 if (gargv[gargc -1] == NULL) 113 fatal ("Out of memory."); 114 } 115 116 } else 117 for (pop = gl.gl_pathv; *pop && gargc < MAX_GARGV-1; pop++) { 118 gargv[gargc++] = strdup(*pop); 119 if (gargv[gargc - 1] == NULL) 120 fatal ("Out of memory."); 121 } 122 globfree(&gl); 123 } 124 gargv[gargc] = NULL; 125 126 iop = NULL; 127 128 switch (pid = fork()) { 129 case -1: /* error */ 130 (void)close(pdes[0]); 131 (void)close(pdes[1]); 132 goto pfree; 133 /* NOTREACHED */ 134 case 0: /* child */ 135 if (*type == 'r') { 136 if (pdes[1] != STDOUT_FILENO) { 137 dup2(pdes[1], STDOUT_FILENO); 138 (void)close(pdes[1]); 139 } 140 dup2(STDOUT_FILENO, STDERR_FILENO); /* stderr too! */ 141 (void)close(pdes[0]); 142 } else { 143 if (pdes[0] != STDIN_FILENO) { 144 dup2(pdes[0], STDIN_FILENO); 145 (void)close(pdes[0]); 146 } 147 (void)close(pdes[1]); 148 } 149 closelog(); 150 151 if (strcmp(gargv[0], "/bin/ls") == 0) { 152 extern int optreset; 153 extern int ls_main(int, char **); 154 155 /* reset getopt for ls_main */ 156 optreset = optind = 1; 157 exit(ls_main(gargc, gargv)); 158 } 159 160 execv(gargv[0], gargv); 161 _exit(1); 162 } 163 /* parent; assume fdopen can't fail... */ 164 if (*type == 'r') { 165 iop = fdopen(pdes[0], type); 166 (void)close(pdes[1]); 167 } else { 168 iop = fdopen(pdes[1], type); 169 (void)close(pdes[0]); 170 } 171 pids[fileno(iop)] = pid; 172 173pfree: for (argc = 1; gargv[argc] != NULL; argc++) 174 free(gargv[argc]); 175 176 return (iop); 177} 178 179int 180ftpd_pclose(iop) 181 FILE *iop; 182{ 183 int fdes, status; 184 pid_t pid; 185 sigset_t sigset, osigset; 186 187 /* 188 * pclose returns -1 if stream is not associated with a 189 * `popened' command, or, if already `pclosed'. 190 */ 191 if (pids == 0 || pids[fdes = fileno(iop)] == 0) 192 return (-1); 193 (void)fclose(iop); 194 sigemptyset(&sigset); 195 sigaddset(&sigset, SIGINT); 196 sigaddset(&sigset, SIGQUIT); 197 sigaddset(&sigset, SIGHUP); 198 sigprocmask(SIG_BLOCK, &sigset, &osigset); 199 while ((pid = waitpid(pids[fdes], &status, 0)) < 0 && errno == EINTR) 200 continue; 201 sigprocmask(SIG_SETMASK, &osigset, NULL); 202 pids[fdes] = 0; 203 if (pid < 0) 204 return (-1); 205 if (WIFEXITED(status)) 206 return (WEXITSTATUS(status)); 207 return (1); 208} 209