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. 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  * @(#) Copyright (c) 1992, 1993, 1994 The Regents of the University of California.  All rights reserved.
  33  * @(#)mount_portal.c   8.6 (Berkeley) 4/26/95
  34  * $FreeBSD: src/sbin/mount_portal/mount_portal.c,v 1.16 1999/10/09 11:54:11 phk Exp $
  35  */
  36
  37 #include <sys/param.h>
  38 #include <sys/wait.h>
  39 #include <sys/socket.h>
  40 #include <sys/un.h>
  41 #include <sys/stat.h>
  42 #include <sys/syslog.h>
  43 #include <sys/mount.h>
  44
  45 #include <err.h>
  46 #include <errno.h>
  47 #include <mntopts.h>
  48 #include <stdio.h>
  49 #include <stdlib.h>
  50 #include <string.h>
  51 #include <sysexits.h>
  52 #include <unistd.h>
  53
  54 #include "pathnames.h"
  55 #include "portald.h"
  56
  57 struct mntopt mopts[] = {
  58         MOPT_STDOPTS,
  59         { NULL, 0, 0, 0 }
  60 };
  61
  62 static void usage(void) __dead2;
  63
  64 static sig_atomic_t readcf;     /* Set when SIGHUP received */
  65
  66 static void
  67 sighup(int sig __unused)
  68 {
  69         readcf ++;
  70 }
  71
  72 static void
  73 sigchld(int sig __unused)
  74 {
  75         pid_t pid;
  76
  77         while ((pid = waitpid((pid_t) -1, NULL, WNOHANG)) > 0)
  78                 ;
  79         /* wrtp - waitpid _doesn't_ return 0 when no children! */
  80 #ifdef notdef
  81         if (pid < 0 && errno != ECHILD)
  82                 syslog(LOG_WARNING, "waitpid: %s", strerror(errno));
  83 #endif
  84 }
  85
  86 int
  87 main(int argc, char **argv)
  88 {
  89         struct portal_args args;
  90         struct sockaddr_un un;
  91         char *conf;
  92         char mountpt[MAXPATHLEN];
  93         int mntflags = 0;
  94         char tag[32];
  95         struct vfsconf vfc;
  96         mode_t um;
  97
  98         qelem q;
  99         int rc;
 100         int so;
 101         int error = 0;
 102
 103         /*
 104          * Crack command line args
 105          */
 106         int ch;
 107
 108         while ((ch = getopt(argc, argv, "o:")) != -1) {
 109                 switch (ch) {
 110                 case 'o':
 111                         getmntopts(optarg, mopts, &mntflags, 0);
 112                         break;
 113                 default:
 114                         error = 1;
 115                         break;
 116                 }
 117         }
 118
 119         if (optind != (argc - 2))
 120                 error = 1;
 121
 122         if (error)
 123                 usage();
 124
 125         /*
 126          * Get config file and mount point
 127          */
 128         conf = argv[optind];
 129
 130         /* resolve the mountpoint with realpath(3) */
 131         checkpath(argv[optind+1], mountpt);
 132
 133         /*
 134          * Construct the listening socket
 135          */
 136         un.sun_family = AF_UNIX;
 137         if (sizeof(_PATH_TMPPORTAL) >= sizeof(un.sun_path)) {
 138                 errx(EX_SOFTWARE, "portal socket name too long");
 139         }
 140         strcpy(un.sun_path, _PATH_TMPPORTAL);
 141         mktemp(un.sun_path);
 142         un.sun_len = strlen(un.sun_path);
 143
 144         so = socket(AF_UNIX, SOCK_STREAM, 0);
 145         if (so < 0) {
 146                 err(EX_OSERR, "socket");
 147         }
 148         um = umask(077);
 149         unlink(un.sun_path);
 150         if (bind(so, (struct sockaddr *) &un, sizeof(un)) < 0)
 151                 err(1, NULL);
 152
 153         unlink(un.sun_path);
 154         umask(um);
 155
 156         listen(so, 5);
 157
 158         args.pa_socket = so;
 159         sprintf(tag, "portal:%d", getpid());
 160         args.pa_config = tag;
 161
 162         error = getvfsbyname("portal", &vfc);
 163         if (error && vfsisloadable("portal")) {
 164                 if (vfsload("portal"))
 165                         err(EX_OSERR, "vfsload(portal)");
 166                 endvfsent();
 167                 error = getvfsbyname("portal", &vfc);
 168         }
 169         if (error)
 170                 errx(EX_OSERR, "portal filesystem is not available");
 171
 172         rc = mount(vfc.vfc_name, mountpt, mntflags, &args);
 173         if (rc < 0)
 174                 err(1, NULL);
 175
 176         /*
 177          * Everything is ready to go - now is a good time to fork
 178          */
 179 #ifndef DEBUG
 180         daemon(0, 0);
 181 #endif
 182
 183         /*
 184          * Start logging (and change name)
 185          */
 186         openlog("portald", LOG_CONS|LOG_PID, LOG_DAEMON);
 187
 188         q.q_forw = q.q_back = &q;
 189         readcf = 1;
 190
 191         signal(SIGCHLD, sigchld);
 192         signal(SIGHUP, sighup);
 193
 194         /*
 195          * Just loop waiting for new connections and activating them
 196          */
 197         for (;;) {
 198                 struct sockaddr_un un2;
 199                 socklen_t len2 = sizeof(un2);
 200                 int so2;
 201                 pid_t pid;
 202                 fd_set fdset;
 203
 204                 /*
 205                  * Check whether we need to re-read the configuration file
 206                  */
 207                 if (readcf) {
 208 #ifdef DEBUG
 209                         printf ("re-reading configuration file\n");
 210 #endif
 211                         readcf = 0;
 212                         conf_read(&q, conf);
 213                         continue;
 214                 }
 215
 216                 /*
 217                  * Accept a new connection
 218                  * Will get EINTR if a signal has arrived, so just
 219                  * ignore that error code
 220                  */
 221                 FD_ZERO(&fdset);
 222                 FD_SET(so, &fdset);
 223                 rc = select(so+1, &fdset, NULL, NULL, NULL);
 224                 if (rc < 0) {
 225                         if (errno == EINTR)
 226                                 continue;
 227                         syslog(LOG_ERR, "select: %s", strerror(errno));
 228                         exit(EX_OSERR);
 229                 }
 230                 if (rc == 0)
 231                         break;
 232                 so2 = accept(so, (struct sockaddr *) &un2, &len2);
 233                 if (so2 < 0) {
 234                         /*
 235                          * The unmount function does a shutdown on the socket
 236                          * which will generated ECONNABORTED on the accept.
 237                          */
 238                         if (errno == ECONNABORTED)
 239                                 break;
 240                         if (errno != EINTR) {
 241                                 syslog(LOG_ERR, "accept: %s", strerror(errno));
 242                                 exit(EX_OSERR);
 243                         }
 244                         continue;
 245                 }
 246
 247                 /*
 248                  * Now fork a new child to deal with the connection
 249                  */
 250         eagain:;
 251                 switch (pid = fork()) {
 252                 case -1:
 253                         if (errno == EAGAIN) {
 254                                 sleep(1);
 255                                 goto eagain;
 256                         }
 257                         syslog(LOG_ERR, "fork: %s", strerror(errno));
 258                         break;
 259                 case 0:
 260                         close(so);
 261                         activate(&q, so2);
 262                         exit(0);
 263                 default:
 264                         close(so2);
 265                         break;
 266                 }
 267         }
 268         syslog(LOG_INFO, "%s unmounted", mountpt);
 269         exit(0);
 270 }
 271
 272 static void
 273 usage(void)
 274 {
 275         fprintf(stderr,
 276             "usage: mount_portal [-o options] config mount-point\n");
 277         exit(EX_USAGE);
 278 }