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. 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  * @(#)popen.c  8.3 (Berkeley) 4/6/94
  37  * $FreeBSD: src/libexec/ftpd/popen.c,v 1.26 2004/11/18 13:46:29 yar Exp $
  38  * $DragonFly: src/libexec/ftpd/popen.c,v 1.3 2006/01/12 13:43:10 corecode Exp $
  39  */
  40
  41 #include <sys/types.h>
  42 #include <sys/wait.h>
  43 #include <netinet/in.h>
  44
  45 #include <errno.h>
  46 #include <glob.h>
  47 #include <signal.h>
  48 #include <stdio.h>
  49 #include <stdlib.h>
  50 #include <string.h>
  51 #include <unistd.h>
  52
  53 #include "extern.h"
  54 #include "pathnames.h"
  55 #include <syslog.h>
  56 #include <time.h>
  57
  58 #define MAXUSRARGS      100
  59 #define MAXGLOBARGS     1000
  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  */
  66 static int *pids;
  67 static int fds;
  68
  69 FILE *
  70 ftpd_popen(char *program, char *type)
  71 {
  72         char *cp;
  73         FILE *iop;
  74         int argc, gargc, pdes[2], pid;
  75         char **pop, *argv[MAXUSRARGS], *gargv[MAXGLOBARGS];
  76
  77         if (((*type != 'r') && (*type != 'w')) || type[1])
  78                 return (NULL);
  79
  80         if (!pids) {
  81                 if ((fds = getdtablesize()) <= 0)
  82                         return (NULL);
  83                 if ((pids = malloc(fds * sizeof(int))) == NULL)
  84                         return (NULL);
  85                 memset(pids, 0, fds * sizeof(int));
  86         }
  87         if (pipe(pdes) < 0)
  88                 return (NULL);
  89
  90         /* break up string into pieces */
  91         for (argc = 0, cp = program; argc < MAXUSRARGS; cp = NULL) {
  92                 if (!(argv[argc++] = strtok(cp, " \t\n")))
  93                         break;
  94         }
  95         argv[argc - 1] = NULL;
  96
  97         /* glob each piece */
  98         gargv[0] = argv[0];
  99         for (gargc = argc = 1; argv[argc] && gargc < (MAXGLOBARGS-1); argc++) {
 100                 glob_t gl;
 101                 int flags = GLOB_BRACE|GLOB_NOCHECK|GLOB_TILDE;
 102
 103                 memset(&gl, 0, sizeof(gl));
 104                 gl.gl_matchc = MAXGLOBARGS;
 105                 flags |= GLOB_LIMIT;
 106                 if (glob(argv[argc], flags, NULL, &gl))
 107                         gargv[gargc++] = strdup(argv[argc]);
 108                 else
 109                         for (pop = gl.gl_pathv; *pop && gargc < (MAXGLOBARGS-1);
 110                              pop++)
 111                                 gargv[gargc++] = strdup(*pop);
 112                 globfree(&gl);
 113         }
 114         gargv[gargc] = NULL;
 115
 116         iop = NULL;
 117         fflush(NULL);
 118         pid = (strcmp(gargv[0], _PATH_LS) == 0) ? fork() : vfork();
 119         switch(pid) {
 120         case -1:                        /* error */
 121                 close(pdes[0]);
 122                 close(pdes[1]);
 123                 goto pfree;
 124                 /* NOTREACHED */
 125         case 0:                         /* child */
 126                 if (*type == 'r') {
 127                         if (pdes[1] != STDOUT_FILENO) {
 128                                 dup2(pdes[1], STDOUT_FILENO);
 129                                 close(pdes[1]);
 130                         }
 131                         dup2(STDOUT_FILENO, STDERR_FILENO); /* stderr too! */
 132                         close(pdes[0]);
 133                 } else {
 134                         if (pdes[0] != STDIN_FILENO) {
 135                                 dup2(pdes[0], STDIN_FILENO);
 136                                 close(pdes[0]);
 137                         }
 138                         close(pdes[1]);
 139                 }
 140                 if (strcmp(gargv[0], _PATH_LS) == 0) {
 141                         /* Reset getopt for ls_main() */
 142                         optreset = optind = optopt = 1;
 143                         /* Close syslogging to remove pwd.db missing msgs */
 144                         closelog();
 145                         /* Trigger to sense new /etc/localtime after chroot */
 146                         if (getenv("TZ") == NULL) {
 147                                 if (setenv("TZ", "", 0) == -1)
 148                                         syslog(LOG_ERR, "setenv: cannot set TZ: %m");
 149                                 tzset();
 150                                 unsetenv("TZ");
 151                                 tzset();
 152                         }
 153                         exit(ls_main(gargc, gargv));
 154                 }
 155                 execv(gargv[0], gargv);
 156                 _exit(1);
 157         }
 158         /* parent; assume fdopen can't fail...  */
 159         if (*type == 'r') {
 160                 iop = fdopen(pdes[0], type);
 161                 close(pdes[1]);
 162         } else {
 163                 iop = fdopen(pdes[1], type);
 164                 close(pdes[0]);
 165         }
 166         pids[fileno(iop)] = pid;
 167
 168 pfree:  for (argc = 1; gargv[argc] != NULL; argc++)
 169                 free(gargv[argc]);
 170
 171         return (iop);
 172 }
 173
 174 int
 175 ftpd_pclose(FILE *iop)
 176 {
 177         int fdes, omask, status;
 178         pid_t pid;
 179
 180         /*
 181          * pclose returns -1 if stream is not associated with a
 182          * `popened' command, or, if already `pclosed'.
 183          */
 184         if (pids == 0 || pids[fdes = fileno(iop)] == 0)
 185                 return (-1);
 186         fclose(iop);
 187         omask = sigblock(sigmask(SIGINT)|sigmask(SIGQUIT)|sigmask(SIGHUP));
 188         while ((pid = waitpid(pids[fdes], &status, 0)) < 0 && errno == EINTR)
 189                 continue;
 190         sigsetmask(omask);
 191         pids[fdes] = 0;
 192         if (pid < 0)
 193                 return (pid);
 194         if (WIFEXITED(status))
 195                 return (WEXITSTATUS(status));
 196         return (1);
 197 }