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 static char rcsid[] = "$Id: popen.c,v 1.3 1994/06/29 01:49:50 deraadt Exp $"; 41 #endif /* not lint */ 42 43 #include <sys/types.h> 44 #include <sys/wait.h> 45 46 #include <errno.h> 47 #include <glob.h> 48 #include <signal.h> 49 #include <stdio.h> 50 #include <stdlib.h> 51 #include <string.h> 52 #include <unistd.h> 53 54 #include "extern.h" 55 56 /* 57 * Special version of popen which avoids call to shell. This ensures noone 58 * may create a pipe to a hidden program as a side effect of a list or dir 59 * command. 60 */ 61 static int *pids; 62 static int fds; 63 64 FILE * 65 ftpd_popen(program, type) 66 char *program, *type; 67 { 68 char *cp; 69 FILE *iop; 70 int argc, gargc, pdes[2], pid; 71 char **pop, *argv[100], *gargv[1000]; 72 73 if (*type != 'r' && *type != 'w' || type[1]) 74 return (NULL); 75 76 if (!pids) { 77 if ((fds = getdtablesize()) <= 0) 78 return (NULL); 79 if ((pids = (int *)malloc((u_int)(fds * sizeof(int)))) == NULL) 80 return (NULL); 81 memset(pids, 0, fds * sizeof(int)); 82 } 83 if (pipe(pdes) < 0) 84 return (NULL); 85 86 /* break up string into pieces */ 87 for (argc = 0, cp = program;; cp = NULL) 88 if (!(argv[argc++] = strtok(cp, " \t\n"))) 89 break; 90 91 /* glob each piece */ 92 gargv[0] = argv[0]; 93 for (gargc = argc = 1; argv[argc]; argc++) { 94 glob_t gl; 95 int flags = GLOB_BRACE|GLOB_NOCHECK|GLOB_QUOTE|GLOB_TILDE; 96 97 memset(&gl, 0, sizeof(gl)); 98 if (glob(argv[argc], flags, NULL, &gl)) 99 gargv[gargc++] = strdup(argv[argc]); 100 else 101 for (pop = gl.gl_pathv; *pop; pop++) 102 gargv[gargc++] = strdup(*pop); 103 globfree(&gl); 104 } 105 gargv[gargc] = NULL; 106 107 iop = NULL; 108 switch(pid = vfork()) { 109 case -1: /* error */ 110 (void)close(pdes[0]); 111 (void)close(pdes[1]); 112 goto pfree; 113 /* NOTREACHED */ 114 case 0: /* child */ 115 if (*type == 'r') { 116 if (pdes[1] != STDOUT_FILENO) { 117 dup2(pdes[1], STDOUT_FILENO); 118 (void)close(pdes[1]); 119 } 120 dup2(STDOUT_FILENO, STDERR_FILENO); /* stderr too! */ 121 (void)close(pdes[0]); 122 } else { 123 if (pdes[0] != STDIN_FILENO) { 124 dup2(pdes[0], STDIN_FILENO); 125 (void)close(pdes[0]); 126 } 127 (void)close(pdes[1]); 128 } 129 execv(gargv[0], gargv); 130 _exit(1); 131 } 132 /* parent; assume fdopen can't fail... */ 133 if (*type == 'r') { 134 iop = fdopen(pdes[0], type); 135 (void)close(pdes[1]); 136 } else { 137 iop = fdopen(pdes[1], type); 138 (void)close(pdes[0]); 139 } 140 pids[fileno(iop)] = pid; 141 142 pfree: for (argc = 1; gargv[argc] != NULL; argc++) 143 free(gargv[argc]); 144 145 return (iop); 146 } 147 148 int 149 ftpd_pclose(iop) 150 FILE *iop; 151 { 152 int fdes, omask, status; 153 pid_t pid; 154 155 /* 156 * pclose returns -1 if stream is not associated with a 157 * `popened' command, or, if already `pclosed'. 158 */ 159 if (pids == 0 || pids[fdes = fileno(iop)] == 0) 160 return (-1); 161 (void)fclose(iop); 162 omask = sigblock(sigmask(SIGINT)|sigmask(SIGQUIT)|sigmask(SIGHUP)); 163 while ((pid = waitpid(pids[fdes], &status, 0)) < 0 && errno == EINTR) 164 continue; 165 (void)sigsetmask(omask); 166 pids[fdes] = 0; 167 if (pid < 0) 168 return (pid); 169 if (WIFEXITED(status)) 170 return (WEXITSTATUS(status)); 171 return (1); 172 } 173