popen.c revision 1.2
1/* $NetBSD: popen.c,v 1.5 1995/04/11 02:45:00 cgd Exp $ */ 2 3/* 4 * Copyright (c) 1988, 1993, 1994 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software written by Ken Arnold and 8 * published in UNIX Review, Vol. 6, No. 8. 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 University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 */ 39 40#ifndef lint 41#if 0 42static char sccsid[] = "@(#)popen.c 8.3 (Berkeley) 4/6/94"; 43#else 44static char rcsid[] = "$NetBSD: popen.c,v 1.5 1995/04/11 02:45:00 cgd Exp $"; 45#endif 46#endif /* not lint */ 47 48#include <sys/types.h> 49#include <sys/wait.h> 50 51#include <errno.h> 52#include <glob.h> 53#include <signal.h> 54#include <stdio.h> 55#include <stdlib.h> 56#include <string.h> 57#include <unistd.h> 58 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 int *pids; 67static int fds; 68 69FILE * 70ftpd_popen(program, type) 71 char *program, *type; 72{ 73 char *cp; 74 FILE *iop; 75 int argc, gargc, pdes[2], pid; 76 char **pop, *argv[100], *gargv[1000]; 77 78 if (*type != 'r' && *type != 'w' || type[1]) 79 return (NULL); 80 81 if (!pids) { 82 if ((fds = getdtablesize()) <= 0) 83 return (NULL); 84 if ((pids = (int *)malloc((u_int)(fds * sizeof(int)))) == NULL) 85 return (NULL); 86 memset(pids, 0, fds * sizeof(int)); 87 } 88 if (pipe(pdes) < 0) 89 return (NULL); 90 91 /* break up string into pieces */ 92 for (argc = 0, cp = program;argc < 100; cp = NULL) 93 if (!(argv[argc++] = strtok(cp, " \t\n"))) 94 break; 95 96 /* glob each piece */ 97 gargv[0] = argv[0]; 98 for (gargc = argc = 1; argv[argc]; argc++) { 99 glob_t gl; 100 int flags = GLOB_BRACE|GLOB_NOCHECK|GLOB_QUOTE|GLOB_TILDE; 101 102 memset(&gl, 0, sizeof(gl)); 103 if (glob(argv[argc], flags, NULL, &gl)) 104 gargv[gargc++] = strdup(argv[argc]); 105 else 106 for (pop = gl.gl_pathv; *pop && gargc < 1000; pop++) 107 gargv[gargc++] = strdup(*pop); 108 globfree(&gl); 109 } 110 gargv[gargc] = NULL; 111 112 iop = NULL; 113 switch(pid = vfork()) { 114 case -1: /* error */ 115 (void)close(pdes[0]); 116 (void)close(pdes[1]); 117 goto pfree; 118 /* NOTREACHED */ 119 case 0: /* child */ 120 if (*type == 'r') { 121 if (pdes[1] != STDOUT_FILENO) { 122 dup2(pdes[1], STDOUT_FILENO); 123 (void)close(pdes[1]); 124 } 125 dup2(STDOUT_FILENO, STDERR_FILENO); /* stderr too! */ 126 (void)close(pdes[0]); 127 } else { 128 if (pdes[0] != STDIN_FILENO) { 129 dup2(pdes[0], STDIN_FILENO); 130 (void)close(pdes[0]); 131 } 132 (void)close(pdes[1]); 133 } 134 execv(gargv[0], gargv); 135 _exit(1); 136 } 137 /* parent; assume fdopen can't fail... */ 138 if (*type == 'r') { 139 iop = fdopen(pdes[0], type); 140 (void)close(pdes[1]); 141 } else { 142 iop = fdopen(pdes[1], type); 143 (void)close(pdes[0]); 144 } 145 pids[fileno(iop)] = pid; 146 147pfree: for (argc = 1; gargv[argc] != NULL; argc++) 148 free(gargv[argc]); 149 150 return (iop); 151} 152 153int 154ftpd_pclose(iop) 155 FILE *iop; 156{ 157 int fdes, omask, status; 158 pid_t pid; 159 sigset_t sigset, osigset; 160 161 /* 162 * pclose returns -1 if stream is not associated with a 163 * `popened' command, or, if already `pclosed'. 164 */ 165 if (pids == 0 || pids[fdes = fileno(iop)] == 0) 166 return (-1); 167 (void)fclose(iop); 168 sigemptyset(&sigset); 169 sigaddset(&sigset, SIGINT); 170 sigaddset(&sigset, SIGQUIT); 171 sigaddset(&sigset, SIGHUP); 172 sigprocmask(SIG_BLOCK, &sigset, &osigset); 173 while ((pid = waitpid(pids[fdes], &status, 0)) < 0 && errno == EINTR) 174 continue; 175 sigprocmask(SIG_SETMASK, &osigset, NULL); 176 pids[fdes] = 0; 177 if (pid < 0) 178 return (pid); 179 if (WIFEXITED(status)) 180 return (WEXITSTATUS(status)); 181 return (1); 182} 183