sbin/mount_portal/mount_portal.c

   1 /*
   2  * Copyright (c) 1992, 1993, 1994
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * This code is derived from software donated to Berkeley by
   6  * Jan-Simon Pendry.
   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  * @(#) Copyright (c) 1992, 1993, 1994 The Regents of the University of California.  All rights reserved.
  37  * @(#)mount_portal.c   8.6 (Berkeley) 4/26/95
  38  * $FreeBSD: src/sbin/mount_portal/mount_portal.c,v 1.16 1999/10/09 11:54:11 phk Exp $
  39  * $DragonFly: src/sbin/mount_portal/mount_portal.c,v 1.6 2005/11/06 12:36:40 swildner Exp $
  40  */
  41
  42 #include <sys/param.h>
  43 #include <sys/wait.h>
  44 #include <sys/socket.h>
  45 #include <sys/un.h>
  46 #include <sys/stat.h>
  47 #include <sys/syslog.h>
  48 #include <sys/mount.h>
  49
  50 #include <err.h>
  51 #include <errno.h>
  52 #include <stdio.h>
  53 #include <stdlib.h>
  54 #include <string.h>
  55 #include <sysexits.h>
  56 #include <unistd.h>
  57
  58 #include "mntopts.h"
  59 #include "pathnames.h"
  60 #include "portald.h"
  61
  62 struct mntopt mopts[] = {
  63         MOPT_STDOPTS,
  64         { NULL }
  65 };
  66
  67 static void usage(void) __dead2;
  68
  69 static sig_atomic_t readcf;     /* Set when SIGHUP received */
  70
  71 static void
  72 sighup(int sig)
  73 {
  74         readcf ++;
  75 }
  76
  77 static void
  78 sigchld(int sig)
  79 {
  80         pid_t pid;
  81
  82         while ((pid = waitpid((pid_t) -1, (int *) 0, WNOHANG)) > 0)
  83                 ;
  84         /* wrtp - waitpid _doesn't_ return 0 when no children! */
  85 #ifdef notdef
  86         if (pid < 0 && errno != ECHILD)
  87                 syslog(LOG_WARNING, "waitpid: %s", strerror(errno));
  88 #endif
  89 }
  90
  91 int
  92 main(int argc, char **argv)
  93 {
  94         struct portal_args args;
  95         struct sockaddr_un un;
  96         char *conf;
  97         char mountpt[MAXPATHLEN];
  98         int mntflags = 0;
  99         char tag[32];
 100         struct vfsconf vfc;
 101         mode_t um;
 102
 103         qelem q;
 104         int rc;
 105         int so;
 106         int error = 0;
 107
 108         /*
 109          * Crack command line args
 110          */
 111         int ch;
 112
 113         while ((ch = getopt(argc, argv, "o:")) != -1) {
 114                 switch (ch) {
 115                 case 'o':
 116                         getmntopts(optarg, mopts, &mntflags, 0);
 117                         break;
 118                 default:
 119                         error = 1;
 120                         break;
 121                 }
 122         }
 123
 124         if (optind != (argc - 2))
 125                 error = 1;
 126
 127         if (error)
 128                 usage();
 129
 130         /*
 131          * Get config file and mount point
 132          */
 133         conf = argv[optind];
 134
 135         /* resolve the mountpoint with realpath(3) */
 136         checkpath(argv[optind+1], mountpt);
 137
 138         /*
 139          * Construct the listening socket
 140          */
 141         un.sun_family = AF_UNIX;
 142         if (sizeof(_PATH_TMPPORTAL) >= sizeof(un.sun_path)) {
 143                 errx(EX_SOFTWARE, "portal socket name too long");
 144         }
 145         strcpy(un.sun_path, _PATH_TMPPORTAL);
 146         mktemp(un.sun_path);
 147         un.sun_len = strlen(un.sun_path);
 148
 149         so = socket(AF_UNIX, SOCK_STREAM, 0);
 150         if (so < 0) {
 151                 err(EX_OSERR, "socket");
 152         }
 153         um = umask(077);
 154         unlink(un.sun_path);
 155         if (bind(so, (struct sockaddr *) &un, sizeof(un)) < 0)
 156                 err(1, NULL);
 157
 158         unlink(un.sun_path);
 159         umask(um);
 160
 161         listen(so, 5);
 162
 163         args.pa_socket = so;
 164         sprintf(tag, "portal:%d", getpid());
 165         args.pa_config = tag;
 166
 167         error = getvfsbyname("portal", &vfc);
 168         if (error && vfsisloadable("portal")) {
 169                 if (vfsload("portal"))
 170                         err(EX_OSERR, "vfsload(portal)");
 171                 endvfsent();
 172                 error = getvfsbyname("portal", &vfc);
 173         }
 174         if (error)
 175                 errx(EX_OSERR, "portal filesystem is not available");
 176
 177         rc = mount(vfc.vfc_name, mountpt, mntflags, &args);
 178         if (rc < 0)
 179                 err(1, NULL);
 180
 181         /*
 182          * Everything is ready to go - now is a good time to fork
 183          */
 184 #ifndef DEBUG
 185         daemon(0, 0);
 186 #endif
 187
 188         /*
 189          * Start logging (and change name)
 190          */
 191         openlog("portald", LOG_CONS|LOG_PID, LOG_DAEMON);
 192
 193         q.q_forw = q.q_back = &q;
 194         readcf = 1;
 195
 196         signal(SIGCHLD, sigchld);
 197         signal(SIGHUP, sighup);
 198
 199         /*
 200          * Just loop waiting for new connections and activating them
 201          */
 202         for (;;) {
 203                 struct sockaddr_un un2;
 204                 int len2 = sizeof(un2);
 205                 int so2;
 206                 pid_t pid;
 207                 fd_set fdset;
 208                 int rc;
 209
 210                 /*
 211                  * Check whether we need to re-read the configuration file
 212                  */
 213                 if (readcf) {
 214 #ifdef DEBUG
 215                         printf ("re-reading configuration file\n");
 216 #endif
 217                         readcf = 0;
 218                         conf_read(&q, conf);
 219                         continue;
 220                 }
 221
 222                 /*
 223                  * Accept a new connection
 224                  * Will get EINTR if a signal has arrived, so just
 225                  * ignore that error code
 226                  */
 227                 FD_ZERO(&fdset);
 228                 FD_SET(so, &fdset);
 229                 rc = select(so+1, &fdset, (fd_set *) 0, (fd_set *) 0, (struct timeval *) 0);
 230                 if (rc < 0) {
 231                         if (errno == EINTR)
 232                                 continue;
 233                         syslog(LOG_ERR, "select: %s", strerror(errno));
 234                         exit(EX_OSERR);
 235                 }
 236                 if (rc == 0)
 237                         break;
 238                 so2 = accept(so, (struct sockaddr *) &un2, &len2);
 239                 if (so2 < 0) {
 240                         /*
 241                          * The unmount function does a shutdown on the socket
 242                          * which will generated ECONNABORTED on the accept.
 243                          */
 244                         if (errno == ECONNABORTED)
 245                                 break;
 246                         if (errno != EINTR) {
 247                                 syslog(LOG_ERR, "accept: %s", strerror(errno));
 248                                 exit(EX_OSERR);
 249                         }
 250                         continue;
 251                 }
 252
 253                 /*
 254                  * Now fork a new child to deal with the connection
 255                  */
 256         eagain:;
 257                 switch (pid = fork()) {
 258                 case -1:
 259                         if (errno == EAGAIN) {
 260                                 sleep(1);
 261                                 goto eagain;
 262                         }
 263                         syslog(LOG_ERR, "fork: %s", strerror(errno));
 264                         break;
 265                 case 0:
 266                         close(so);
 267                         activate(&q, so2);
 268                         exit(0);
 269                 default:
 270                         close(so2);
 271                         break;
 272                 }
 273         }
 274         syslog(LOG_INFO, "%s unmounted", mountpt);
 275         exit(0);
 276 }
 277
 278 static void
 279 usage(void)
 280 {
 281         fprintf(stderr,
 282             "usage: mount_portal [-o options] config mount-point\n");
 283         exit(EX_USAGE);
 284 }