appl/ftp/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  */
  37
  38 #ifdef HAVE_CONFIG_H
  39 #include <config.h>
  40 RCSID("$Id$");
  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  */
  73 static int *pids;
  74 static int fds;
  75
  76 /* return path prepended with ~ftp if that file exists, otherwise
  77  * return path unchanged
  78  */
  79
  80 const char *
  81 ftp_rooted(const char *path)
  82 {
  83     static char home[MaxPathLen] = "";
  84     static char newpath[MaxPathLen];
  85     struct passwd *pwd;
  86
  87     if(!home[0])
  88         if((pwd = k_getpwnam("ftp")))
  89             strlcpy(home, pwd->pw_dir, sizeof(home));
  90     snprintf(newpath, sizeof(newpath), "%s/%s", home, path);
  91     if(access(newpath, X_OK))
  92         strlcpy(newpath, path, sizeof(newpath));
  93     return newpath;
  94 }
  95
  96
  97 #define MAXARGS 100
  98 #define MAXGLOBS 1000
  99
 100 FILE *
 101 ftpd_popen(char *program, char *type, int do_stderr, int no_glob)
 102 {
 103         char *cp;
 104         FILE *iop;
 105         int argc, gargc, pdes[2], pid;
 106         char **pop, *argv[MAXARGS], *gargv[MAXGLOBS];
 107         char *foo;
 108
 109         if (strcmp(type, "r") && strcmp(type, "w"))
 110                 return (NULL);
 111
 112         if (!pids) {
 113
 114             /* This function is ugly and should be rewritten, in
 115              * modern unices there is no such thing as a maximum
 116              * filedescriptor.
 117              */
 118
 119             fds = getdtablesize();
 120             pids = (int*)calloc(fds, sizeof(int));
 121             if(!pids)
 122                 return NULL;
 123         }
 124         if (pipe(pdes) < 0)
 125                 return (NULL);
 126
 127         /* break up string into pieces */
 128         foo = NULL;
 129         for (argc = 0, cp = program; argc < MAXARGS - 1; cp = NULL) {
 130                 if (!(argv[argc++] = strtok_r(cp, " \t\n", &foo)))
 131                         break;
 132         }
 133         argv[MAXARGS - 1] = NULL;
 134
 135         gargv[0] = (char*)ftp_rooted(argv[0]);
 136         /* glob each piece */
 137         for (gargc = argc = 1; argv[argc] && gargc < MAXGLOBS - 1; argc++) {
 138                 glob_t gl;
 139                 int flags = GLOB_BRACE|GLOB_NOCHECK|GLOB_QUOTE|GLOB_TILDE
 140                     |
 141 #ifdef GLOB_MAXPATH
 142         GLOB_MAXPATH
 143 #else
 144         GLOB_LIMIT
 145 #endif
 146                     ;
 147
 148                 memset(&gl, 0, sizeof(gl));
 149                 if (no_glob ||
 150                     glob(argv[argc], flags, NULL, &gl) ||
 151                     gl.gl_pathc == 0)
 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
 200 pfree:
 201         for (argc = 1; gargv[argc] != NULL; argc++)
 202             free(gargv[argc]);
 203
 204
 205         return (iop);
 206 }
 207
 208 int
 209 ftpd_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 }