libexec/ftpd/popen.c

   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. Neither the name of the University nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  *
  32  * @(#)popen.c  8.3 (Berkeley) 4/6/94
  33  * $FreeBSD: src/libexec/ftpd/popen.c,v 1.26 2004/11/18 13:46:29 yar Exp $
  34  */
  35
  36 #include <sys/types.h>
  37 #include <sys/wait.h>
  38 #include <netinet/in.h>
  39
  40 #include <errno.h>
  41 #include <glob.h>
  42 #include <signal.h>
  43 #include <stdio.h>
  44 #include <stdlib.h>
  45 #include <string.h>
  46 #include <unistd.h>
  47
  48 #include "extern.h"
  49 #include "pathnames.h"
  50 #include <syslog.h>
  51 #include <time.h>
  52
  53 #define MAXUSRARGS      100
  54 #define MAXGLOBARGS     1000
  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(char *program, char *type)
  66 {
  67         char *cp;
  68         FILE *iop;
  69         int argc, gargc, pdes[2], pid;
  70         char **pop, *argv[MAXUSRARGS], *gargv[MAXGLOBARGS];
  71
  72         if (((*type != 'r') && (*type != 'w')) || type[1])
  73                 return (NULL);
  74
  75         if (!pids) {
  76                 if ((fds = getdtablesize()) <= 0)
  77                         return (NULL);
  78                 if ((pids = malloc(fds * sizeof(int))) == NULL)
  79                         return (NULL);
  80                 memset(pids, 0, fds * sizeof(int));
  81         }
  82         if (pipe(pdes) < 0)
  83                 return (NULL);
  84
  85         /* break up string into pieces */
  86         for (argc = 0, cp = program; argc < MAXUSRARGS; cp = NULL) {
  87                 if (!(argv[argc++] = strtok(cp, " \t\n")))
  88                         break;
  89         }
  90         argv[argc - 1] = NULL;
  91
  92         /* glob each piece */
  93         gargv[0] = argv[0];
  94         for (gargc = argc = 1; argv[argc] && gargc < (MAXGLOBARGS-1); argc++) {
  95                 glob_t gl;
  96                 int flags = GLOB_BRACE|GLOB_NOCHECK|GLOB_TILDE;
  97
  98                 memset(&gl, 0, sizeof(gl));
  99                 gl.gl_matchc = MAXGLOBARGS;
 100                 /*flags |= GLOB_LIMIT;*/
 101                 if (glob(argv[argc], flags, NULL, &gl))
 102                         gargv[gargc++] = strdup(argv[argc]);
 103                 else
 104                         for (pop = gl.gl_pathv; *pop && gargc < (MAXGLOBARGS-1);
 105                              pop++)
 106                                 gargv[gargc++] = strdup(*pop);
 107                 globfree(&gl);
 108         }
 109         gargv[gargc] = NULL;
 110
 111         iop = NULL;
 112         fflush(NULL);
 113         pid = (strcmp(gargv[0], _PATH_LS) == 0) ? fork() : vfork();
 114         switch(pid) {
 115         case -1:                        /* error */
 116                 close(pdes[0]);
 117                 close(pdes[1]);
 118                 goto pfree;
 119                 /* NOTREACHED */
 120         case 0:                         /* child */
 121                 if (*type == 'r') {
 122                         if (pdes[1] != STDOUT_FILENO) {
 123                                 dup2(pdes[1], STDOUT_FILENO);
 124                                 close(pdes[1]);
 125                         }
 126                         dup2(STDOUT_FILENO, STDERR_FILENO); /* stderr too! */
 127                         close(pdes[0]);
 128                 } else {
 129                         if (pdes[0] != STDIN_FILENO) {
 130                                 dup2(pdes[0], STDIN_FILENO);
 131                                 close(pdes[0]);
 132                         }
 133                         close(pdes[1]);
 134                 }
 135                 if (strcmp(gargv[0], _PATH_LS) == 0) {
 136                         /* Reset getopt for ls_main() */
 137                         optreset = optind = optopt = 1;
 138                         /* Close syslogging to remove pwd.db missing msgs */
 139                         closelog();
 140                         /* Trigger to sense new /etc/localtime after chroot */
 141                         if (getenv("TZ") == NULL) {
 142                                 if (setenv("TZ", "", 0) == -1)
 143                                         syslog(LOG_ERR, "setenv: cannot set TZ: %m");
 144                                 tzset();
 145                                 unsetenv("TZ");
 146                                 tzset();
 147                         }
 148                         exit(ls_main(gargc, gargv));
 149                 }
 150                 execv(gargv[0], gargv);
 151                 _exit(1);
 152         }
 153         /* parent; assume fdopen can't fail...  */
 154         if (*type == 'r') {
 155                 iop = fdopen(pdes[0], type);
 156                 close(pdes[1]);
 157         } else {
 158                 iop = fdopen(pdes[1], type);
 159                 close(pdes[0]);
 160         }
 161         pids[fileno(iop)] = pid;
 162
 163 pfree:  for (argc = 1; gargv[argc] != NULL; argc++)
 164                 free(gargv[argc]);
 165
 166         return (iop);
 167 }
 168
 169 int
 170 ftpd_pclose(FILE *iop)
 171 {
 172         int fdes, omask, status;
 173         pid_t pid;
 174
 175         /*
 176          * pclose returns -1 if stream is not associated with a
 177          * `popened' command, or, if already `pclosed'.
 178          */
 179         if (pids == NULL || pids[fdes = fileno(iop)] == 0)
 180                 return (-1);
 181         fclose(iop);
 182         omask = sigblock(sigmask(SIGINT)|sigmask(SIGQUIT)|sigmask(SIGHUP));
 183         while ((pid = waitpid(pids[fdes], &status, 0)) < 0 && errno == EINTR)
 184                 continue;
 185         sigsetmask(omask);
 186         pids[fdes] = 0;
 187         if (pid < 0)
 188                 return (pid);
 189         if (WIFEXITED(status))
 190                 return (WEXITSTATUS(status));
 191         return (1);
 192 }