rpc_statd.tproj/statd.c

   1 /*
   2  * Copyright (c) 1995
   3  *      A.R. Gordon (andrew.gordon@net-tel.co.uk).  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed for the FreeBSD project
  16  * 4. Neither the name of the author nor the names of any co-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 ANDREW GORDON 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 AUTHOR 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  */
  33
  34 #ifndef lint
  35 static const char rcsid[] =
  36   "$FreeBSD$";
  37 #endif /* not lint */
  38
  39 /* main() function for status monitor daemon.  Some of the code in this */
  40 /* file was generated by running rpcgen /usr/include/rpcsvc/sm_inter.x  */
  41 /* The actual program logic is in the file procs.c                      */
  42
  43 #include <err.h>
  44 #include <stdio.h>
  45 #include <stdlib.h>
  46 #include <rpc/rpc.h>
  47 #include <rpc/pmap_clnt.h>
  48 #include <string.h>
  49 #include <syslog.h>
  50 #include <sys/types.h>
  51 #include <sys/wait.h>
  52 #include <signal.h>
  53 #include <unistd.h>
  54 #include <fcntl.h>
  55 #include <sys/stat.h>
  56 #include "statd.h"
  57
  58 int debug = 0;          /* Controls syslog() calls for debug messages   */
  59 int notify_only = 0;    /* only send SM_NOTIFY messages */
  60 const char *pid_file = NULL; /* name of any pid file that has been claimed */
  61
  62 extern void sm_prog_1(struct svc_req *rqstp, SVCXPRT *transp);
  63 static void handle_sigchld(int sig);
  64 static void handle_sig_cleanup(int sig);
  65 static void cleanup_pid_file(void);
  66 static void usage(void);
  67
  68 int
  69 main(int argc, char **argv)
  70 {
  71   SVCXPRT *transp;
  72   struct sigaction sa;
  73   int c;
  74   struct timespec ts;
  75
  76   while ((c = getopt(argc, argv, "dn")) != EOF)
  77     switch (c) {
  78     case 'd':
  79       debug = 1;
  80       break;
  81     case 'n':
  82       notify_only = 1;
  83       break;
  84     default:
  85       usage();
  86     }
  87
  88   /* Install signal handler to remove any pid file */
  89   signal(SIGINT, handle_sig_cleanup);
  90   signal(SIGTERM, handle_sig_cleanup);
  91   signal(SIGHUP, handle_sig_cleanup);
  92   signal(SIGQUIT, handle_sig_cleanup);
  93
  94   init_file("/var/db/statd.status");
  95
  96   openlog("rpc.statd", 0, LOG_DAEMON);
  97
  98   if (notify_only) {
  99     notify_hosts();
 100     exit(0);
 101   }
 102
 103   /* Note that it is NOT sensible to run this program from inetd - the  */
 104   /* protocol assumes that it will run immediately at boot time.        */
 105   daemon(0, 0);
 106
 107   if (claim_pid_file("/var/run/statd.pid", 0) < 0)
 108     errx(1, "rpc.statd already running");
 109
 110   /* start portmapper, in case it hasn't been started yet */
 111   system("portmap");
 112   /* sleep a little to give portmap a chance to start */
 113   /* (better to sleep 50ms now than to timeout on portmap calls) */
 114   ts.tv_sec = 0;
 115   ts.tv_nsec = 50*1000*1000;
 116   nanosleep(&ts, NULL);
 117
 118   (void)pmap_unset(SM_PROG, SM_VERS);
 119
 120   transp = svcudp_create(RPC_ANYSOCK);
 121   if (transp == NULL)
 122     errx(1, "cannot create udp service");
 123   if (!svc_register(transp, SM_PROG, SM_VERS, sm_prog_1, IPPROTO_UDP))
 124     errx(1, "unable to register (SM_PROG, SM_VERS, udp)");
 125
 126   transp = svctcp_create(RPC_ANYSOCK, 0, 0);
 127   if (transp == NULL)
 128     errx(1, "cannot create tcp service");
 129   if (!svc_register(transp, SM_PROG, SM_VERS, sm_prog_1, IPPROTO_TCP))
 130     errx(1, "unable to register (SM_PROG, SM_VERS, tcp)");
 131
 132   if (debug) syslog(LOG_INFO, "Starting - debug enabled");
 133   else syslog(LOG_INFO, "Starting");
 134
 135   /* Install signal handler to collect exit status of child processes   */
 136   sa.sa_handler = handle_sigchld;
 137   sigemptyset(&sa.sa_mask);
 138   sigaddset(&sa.sa_mask, SIGCHLD);
 139   sa.sa_flags = SA_RESTART;
 140   sigaction(SIGCHLD, &sa, NULL);
 141
 142   /* Initialisation now complete - start operating                      */
 143   notify_hosts();       /* Forks a process (if necessary) to do the     */
 144                         /* SM_NOTIFY calls, which may be slow.          */
 145
 146   svc_run();    /* Should never return                                  */
 147   exit(1);
 148 }
 149
 150 static void
 151 usage()
 152 {
 153       fprintf(stderr, "usage: rpc.statd [-dn]\n");
 154       exit(1);
 155 }
 156
 157 /* handle_sigchld ---------------------------------------------------------- */
 158 /*
 159    Purpose:     Catch SIGCHLD and collect process status
 160    Returns:     Nothing.
 161    Notes:       No special action required, other than to collect the
 162                 process status and hence allow the child to die:
 163                 we only use child processes for asynchronous transmission
 164                 of SM_NOTIFY to other systems, so it is normal for the
 165                 children to exit when they have done their work.
 166 */
 167
 168 static void handle_sigchld(int sig __unused)
 169 {
 170   int pid, status;
 171   pid = wait4(-1, &status, WNOHANG, (struct rusage*)0);
 172   if (!pid) syslog(LOG_ERR, "Phantom SIGCHLD??");
 173   else if (status == 0)
 174   {
 175     if (debug) syslog(LOG_DEBUG, "Child %d exited OK", pid);
 176   }
 177   else syslog(LOG_ERR, "Child %d failed with status %d", pid,
 178     WEXITSTATUS(status));
 179 }
 180
 181
 182 /* claim_pid_file ---------------------------------------------------------- */
 183 /*
 184    Purpose:     take ownership of and store pid in given pid_file
 185    Returns:     0 on success or -1 on failure
 186    Notes:       force parameter requests that current owner (if any) of
 187                 pid file be terminated.
 188 */
 189
 190 int
 191 claim_pid_file(const char *name, int force)
 192 {
 193   int pidfd, rv, retried = 0;
 194   FILE *pidfile;
 195
 196 try_again:
 197
 198   /* attempt exclusive open of pid file */
 199   pidfd = open(name, O_EXCL|O_CREAT|O_WRONLY,
 200                S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH);
 201   if (pidfd < 0) {
 202     char buf[16];
 203     pid_t pid;
 204     if (retried)
 205       return -1;
 206     bzero(buf, 16);
 207     retried = 1;
 208     /* pid file busy, check validity */
 209     pidfd = open(name, O_RDONLY);
 210     if (pidfd < 0)
 211       goto try_again;
 212     rv = read(pidfd, buf, 15);
 213     close(pidfd);
 214     if (rv <= 0)
 215       goto try_again;
 216     pid = atoi(buf);
 217     if (pid <= 0)
 218       goto try_again;
 219     rv = kill(pid, force ? SIGKILL : 0);
 220     /* if can't signal, assume stale pid file */
 221     if ((rv < 0) || force)
 222       unlink(name);
 223     goto try_again;
 224   }
 225   pid_file = name;
 226   atexit(cleanup_pid_file);
 227
 228   pidfile = fdopen(pidfd, "w");
 229   if (pidfile) {
 230     fchmod(pidfd, S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH);
 231     fprintf(pidfile, "%d\n", getpid());
 232     fclose(pidfile);
 233   } else
 234     perror("fdopen");
 235   close(pidfd);
 236   return 0;
 237 }
 238
 239
 240 /* cleanup_pid_file -------------------------------------------------------- */
 241 /*
 242    Purpose:     delete any pid_file that has been claimed
 243    Returns:     Nothing
 244 */
 245
 246 void
 247 cleanup_pid_file(void)
 248 {
 249   if (pid_file) {
 250     unlink(pid_file);
 251     pid_file = NULL;
 252   }
 253 }
 254
 255
 256 /* handle_sig_cleanup ------------------------------------------------------ */
 257 /*
 258    Purpose:     call pid file cleanup function on signal
 259    Returns:     Nothing
 260 */
 261
 262 static void
 263 handle_sig_cleanup(int sig __unused)
 264 {
 265   cleanup_pid_file();
 266   exit(1);
 267 }
 268