libexec/ftpd/popen.c

   1 /*      $NetBSD: popen.c,v 1.37 2010/03/20 18:23:30 christos Exp $      */
   2
   3 /*-
   4  * Copyright (c) 1999-2009 The NetBSD Foundation, Inc.
   5  * All rights reserved.
   6  *
   7  * This code is derived from software contributed to The NetBSD Foundation
   8  * by Luke Mewburn.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  29  * POSSIBILITY OF SUCH DAMAGE.
  30  */
  31
  32 /*
  33  * Copyright (c) 1988, 1993, 1994
  34  *      The Regents of the University of California.  All rights reserved.
  35  *
  36  * This code is derived from software written by Ken Arnold and
  37  * published in UNIX Review, Vol. 6, No. 8.
  38  *
  39  * Redistribution and use in source and binary forms, with or without
  40  * modification, are permitted provided that the following conditions
  41  * are met:
  42  * 1. Redistributions of source code must retain the above copyright
  43  *    notice, this list of conditions and the following disclaimer.
  44  * 2. Redistributions in binary form must reproduce the above copyright
  45  *    notice, this list of conditions and the following disclaimer in the
  46  *    documentation and/or other materials provided with the distribution.
  47  * 3. Neither the name of the University nor the names of its contributors
  48  *    may be used to endorse or promote products derived from this software
  49  *    without specific prior written permission.
  50  *
  51  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  52  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  53  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  54  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  55  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  56  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  57  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  58  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  59  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  60  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  61  * SUCH DAMAGE.
  62  *
  63  */
  64
  65 #include <sys/cdefs.h>
  66 #ifndef lint
  67 #if 0
  68 static char sccsid[] = "@(#)popen.c     8.3 (Berkeley) 4/6/94";
  69 #else
  70 __RCSID("$NetBSD: popen.c,v 1.37 2010/03/20 18:23:30 christos Exp $");
  71 #endif
  72 #endif /* not lint */
  73
  74 #include <sys/types.h>
  75 #include <sys/param.h>
  76 #include <sys/wait.h>
  77
  78 #include <errno.h>
  79 #include <glob.h>
  80 #include <signal.h>
  81 #include <stdio.h>
  82 #include <stdlib.h>
  83 #include <string.h>
  84 #include <stringlist.h>
  85 #include <syslog.h>
  86 #include <unistd.h>
  87
  88 #ifdef KERBEROS5
  89 #include <krb5/krb5.h>
  90 #endif
  91
  92 #include "extern.h"
  93
  94 #define INCR    100
  95 /*
  96  * Special version of popen which avoids call to shell.  This ensures no-one
  97  * may create a pipe to a hidden program as a side effect of a list or dir
  98  * command.
  99  * If stderrfd != -1, then send stderr of a read command there,
 100  * otherwise close stderr.
 101  */
 102 static int *pids;
 103 static int fds;
 104
 105 extern int ls_main(int, char *[]);
 106
 107 FILE *
 108 ftpd_popen(const char *argv[], const char *ptype, int stderrfd)
 109 {
 110         FILE *iop;
 111         int argc, pdes[2], pid;
 112         volatile int isls;
 113         char **pop;
 114         StringList *sl;
 115
 116         iop = NULL;
 117         isls = 0;
 118         if ((*ptype != 'r' && *ptype != 'w') || ptype[1])
 119                 return (NULL);
 120
 121         if (!pids) {
 122                 if ((fds = getdtablesize()) <= 0)
 123                         return (NULL);
 124                 if ((pids = (int *)malloc((unsigned int)(fds * sizeof(int)))) == NULL)
 125                         return (NULL);
 126                 memset(pids, 0, fds * sizeof(int));
 127         }
 128         if (pipe(pdes) < 0)
 129                 return (NULL);
 130
 131         if ((sl = sl_init()) == NULL)
 132                 goto pfree;
 133
 134                                         /* glob each piece */
 135         if (sl_add(sl, ftpd_strdup(argv[0])) == -1)
 136                 goto pfree;
 137         for (argc = 1; argv[argc]; argc++) {
 138                 glob_t gl;
 139                 int flags = GLOB_BRACE|GLOB_NOCHECK|GLOB_TILDE|GLOB_LIMIT;
 140
 141                 memset(&gl, 0, sizeof(gl));
 142                 if (glob(argv[argc], flags, NULL, &gl)
 143                     || gl.gl_pathv == NULL)  {
 144                         if (sl_add(sl, ftpd_strdup(argv[argc])) == -1) {
 145                                 globfree(&gl);
 146                                 goto pfree;
 147                         }
 148                 } else {
 149                         for (pop = gl.gl_pathv; *pop; pop++) {
 150                                 if (sl_add(sl, ftpd_strdup(*pop)) == -1) {
 151                                         globfree(&gl);
 152                                         goto pfree;
 153                                 }
 154                         }
 155                 }
 156                 globfree(&gl);
 157         }
 158         if (sl_add(sl, NULL) == -1)
 159                 goto pfree;
 160
 161 #ifndef NO_INTERNAL_LS
 162         isls = (strcmp(sl->sl_str[0], INTERNAL_LS) == 0);
 163 #endif
 164
 165         pid = isls ? fork() : vfork();
 166         switch (pid) {
 167         case -1:                        /* error */
 168                 (void)close(pdes[0]);
 169                 (void)close(pdes[1]);
 170                 goto pfree;
 171                 /* NOTREACHED */
 172         case 0:                         /* child */
 173                 if (*ptype == 'r') {
 174                         if (pdes[1] != STDOUT_FILENO) {
 175                                 dup2(pdes[1], STDOUT_FILENO);
 176                                 (void)close(pdes[1]);
 177                         }
 178                         if (stderrfd == -1)
 179                                 (void)close(STDERR_FILENO);
 180                         else
 181                                 dup2(stderrfd, STDERR_FILENO);
 182                         (void)close(pdes[0]);
 183                 } else {
 184                         if (pdes[0] != STDIN_FILENO) {
 185                                 dup2(pdes[0], STDIN_FILENO);
 186                                 (void)close(pdes[0]);
 187                         }
 188                         (void)close(pdes[1]);
 189                 }
 190 #ifndef NO_INTERNAL_LS
 191                 if (isls) {     /* use internal ls */
 192                         optreset = optind = optopt = 1;
 193                         closelog();
 194                         exit(ls_main(sl->sl_cur - 1, sl->sl_str));
 195                 }
 196 #endif
 197
 198                 execv(sl->sl_str[0], sl->sl_str);
 199                 _exit(1);
 200         }
 201         /* parent; assume fdopen can't fail...  */
 202         if (*ptype == 'r') {
 203                 iop = fdopen(pdes[0], ptype);
 204                 (void)close(pdes[1]);
 205         } else {
 206                 iop = fdopen(pdes[1], ptype);
 207                 (void)close(pdes[0]);
 208         }
 209         pids[fileno(iop)] = pid;
 210
 211  pfree:
 212         if (sl)
 213                 sl_free(sl, 1);
 214         return (iop);
 215 }
 216
 217 int
 218 ftpd_pclose(FILE *iop)
 219 {
 220         int fdes, status;
 221         pid_t pid;
 222         sigset_t nsigset, osigset;
 223
 224         /*
 225          * pclose returns -1 if stream is not associated with a
 226          * `popened' command, or, if already `pclosed'.
 227          */
 228         if (pids == 0 || pids[fdes = fileno(iop)] == 0)
 229                 return (-1);
 230         (void)fclose(iop);
 231         sigemptyset(&nsigset);
 232         sigaddset(&nsigset, SIGINT);
 233         sigaddset(&nsigset, SIGQUIT);
 234         sigaddset(&nsigset, SIGHUP);
 235         sigprocmask(SIG_BLOCK, &nsigset, &osigset);
 236         while ((pid = waitpid(pids[fdes], &status, 0)) < 0 && errno == EINTR)
 237                 continue;
 238         sigprocmask(SIG_SETMASK, &osigset, NULL);
 239         pids[fdes] = 0;
 240         if (pid < 0)
 241                 return (pid);
 242         if (WIFEXITED(status))
 243                 return (WEXITSTATUS(status));
 244         return (1);
 245 }