popen.c revision 90926
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#ifdef HAVE_CONFIG_H 39#include <config.h> 40RCSID("$Id: popen.c,v 1.25 2001/06/19 10:00:25 assar Exp $"); 41#endif 42 43#include <sys/types.h> 44#ifdef TIME_WITH_SYS_TIME 45#include <sys/time.h> 46#include <time.h> 47#elif defined(HAVE_SYS_TIME_H) 48#include <sys/time.h> 49#else 50#include <time.h> 51#endif 52#ifdef HAVE_SYS_RESOURCE_H 53#include <sys/resource.h> 54#endif 55#include <sys/wait.h> 56 57#include <errno.h> 58#include <glob.h> 59#include <signal.h> 60#include <stdio.h> 61#include <stdlib.h> 62#include <string.h> 63#include <unistd.h> 64#include <roken.h> 65#include "extern.h" 66 67 68/* 69 * Special version of popen which avoids call to shell. This ensures 70 * no one may create a pipe to a hidden program as a side effect of a 71 * list or dir command. 72 */ 73static int *pids; 74static int fds; 75 76extern int dochroot; 77 78/* return path prepended with ~ftp if that file exists, otherwise 79 * return path unchanged 80 */ 81 82const char * 83ftp_rooted(const char *path) 84{ 85 static char home[MaxPathLen] = ""; 86 static char newpath[MaxPathLen]; 87 struct passwd *pwd; 88 89 if(!home[0]) 90 if((pwd = k_getpwnam("ftp"))) 91 strlcpy(home, pwd->pw_dir, sizeof(home)); 92 snprintf(newpath, sizeof(newpath), "%s/%s", home, path); 93 if(access(newpath, X_OK)) 94 strlcpy(newpath, path, sizeof(newpath)); 95 return newpath; 96} 97 98 99#define MAXARGS 100 100#define MAXGLOBS 1000 101 102FILE * 103ftpd_popen(char *program, char *type, int do_stderr, int no_glob) 104{ 105 char *cp; 106 FILE *iop; 107 int argc, gargc, pdes[2], pid; 108 char **pop, *argv[MAXARGS], *gargv[MAXGLOBS]; 109 char *foo; 110 111 if (strcmp(type, "r") && strcmp(type, "w")) 112 return (NULL); 113 114 if (!pids) { 115 116 /* This function is ugly and should be rewritten, in 117 * modern unices there is no such thing as a maximum 118 * filedescriptor. 119 */ 120 121 fds = getdtablesize(); 122 pids = (int*)calloc(fds, sizeof(int)); 123 if(!pids) 124 return NULL; 125 } 126 if (pipe(pdes) < 0) 127 return (NULL); 128 129 /* break up string into pieces */ 130 foo = NULL; 131 for (argc = 0, cp = program; argc < MAXARGS - 1; cp = NULL) { 132 if (!(argv[argc++] = strtok_r(cp, " \t\n", &foo))) 133 break; 134 } 135 argv[MAXARGS - 1] = NULL; 136 137 gargv[0] = (char*)ftp_rooted(argv[0]); 138 /* glob each piece */ 139 for (gargc = argc = 1; argv[argc] && gargc < MAXGLOBS - 1; argc++) { 140 glob_t gl; 141 int flags = GLOB_BRACE|GLOB_NOCHECK|GLOB_QUOTE|GLOB_TILDE 142 | 143#ifdef GLOB_MAXPATH 144 GLOB_MAXPATH 145#else 146 GLOB_LIMIT 147#endif 148 ; 149 150 memset(&gl, 0, sizeof(gl)); 151 if (no_glob || glob(argv[argc], flags, NULL, &gl)) 152 gargv[gargc++] = strdup(argv[argc]); 153 else 154 for (pop = gl.gl_pathv; 155 *pop && gargc < MAXGLOBS - 1; 156 pop++) 157 gargv[gargc++] = strdup(*pop); 158 globfree(&gl); 159 } 160 gargv[gargc] = NULL; 161 162 iop = NULL; 163 switch(pid = fork()) { 164 case -1: /* error */ 165 close(pdes[0]); 166 close(pdes[1]); 167 goto pfree; 168 /* NOTREACHED */ 169 case 0: /* child */ 170 if (*type == 'r') { 171 if (pdes[1] != STDOUT_FILENO) { 172 dup2(pdes[1], STDOUT_FILENO); 173 close(pdes[1]); 174 } 175 if(do_stderr) 176 dup2(STDOUT_FILENO, STDERR_FILENO); 177 close(pdes[0]); 178 } else { 179 if (pdes[0] != STDIN_FILENO) { 180 dup2(pdes[0], STDIN_FILENO); 181 close(pdes[0]); 182 } 183 close(pdes[1]); 184 } 185 execv(gargv[0], gargv); 186 gargv[0] = argv[0]; 187 execv(gargv[0], gargv); 188 _exit(1); 189 } 190 /* parent; assume fdopen can't fail... */ 191 if (*type == 'r') { 192 iop = fdopen(pdes[0], type); 193 close(pdes[1]); 194 } else { 195 iop = fdopen(pdes[1], type); 196 close(pdes[0]); 197 } 198 pids[fileno(iop)] = pid; 199 200pfree: 201 for (argc = 1; gargv[argc] != NULL; argc++) 202 free(gargv[argc]); 203 204 205 return (iop); 206} 207 208int 209ftpd_pclose(FILE *iop) 210{ 211 int fdes, status; 212 pid_t pid; 213 sigset_t sigset, osigset; 214 215 /* 216 * pclose returns -1 if stream is not associated with a 217 * `popened' command, or, if already `pclosed'. 218 */ 219 if (pids == 0 || pids[fdes = fileno(iop)] == 0) 220 return (-1); 221 fclose(iop); 222 sigemptyset(&sigset); 223 sigaddset(&sigset, SIGINT); 224 sigaddset(&sigset, SIGQUIT); 225 sigaddset(&sigset, SIGHUP); 226 sigprocmask(SIG_BLOCK, &sigset, &osigset); 227 while ((pid = waitpid(pids[fdes], &status, 0)) < 0 && errno == EINTR) 228 continue; 229 sigprocmask(SIG_SETMASK, &osigset, NULL); 230 pids[fdes] = 0; 231 if (pid < 0) 232 return (pid); 233 if (WIFEXITED(status)) 234 return (WEXITSTATUS(status)); 235 return (1); 236} 237