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 <sys/sysctl.h>
  57 #include "statd.h"
  58
  59 int debug = 0;          /* Controls syslog() calls for debug messages   */
  60 int notify_only = 0;    /* only send SM_NOTIFY messages */
  61 const char *pid_file = NULL; /* name of any pid file that has been claimed */
  62
  63 extern void sm_prog_1(struct svc_req *rqstp, SVCXPRT *transp);
  64 static void handle_sigchld(int sig);
  65 static void handle_sig_cleanup(int sig);
  66 static void cleanup_pid_file(void);
  67 static void usage(void);
  68
  69 int
  70 main(int argc, char **argv)
  71 {
  72   SVCXPRT *transp;
  73   struct sigaction sa;
  74   int c;
  75   int mib[6];
  76   int oldstate;
  77   int oldsize;
  78   int newstate;
  79
  80
  81   while ((c = getopt(argc, argv, "dn")) != EOF)
  82     switch (c) {
  83     case 'd':
  84       debug = 1;
  85       break;
  86     case 'n':
  87       notify_only = 1;
  88       break;
  89     default:
  90       usage();
  91     }
  92
  93   /* Install signal handler to remove any pid file */
  94   signal(SIGINT, handle_sig_cleanup);
  95   signal(SIGTERM, handle_sig_cleanup);
  96   signal(SIGHUP, handle_sig_cleanup);
  97   signal(SIGQUIT, handle_sig_cleanup);
  98
  99   init_file("/var/db/statd.status");
 100
 101   openlog("rpc.statd", 0, LOG_DAEMON);
 102
 103   if (notify_only) {
 104     notify_hosts();
 105     exit(0);
 106   }
 107
 108   /* Note that it is NOT sensible to run this program from inetd - the  */
 109   /* protocol assumes that it will run immediately at boot time.        */
 110   daemon(0, 0);
 111
 112   mib[0] = CTL_KERN;
 113   mib[1] = KERN_PROCDELAYTERM;
 114
 115   oldstate = 0;
 116   oldsize = 4;
 117   newstate  = 1;
 118
 119   if (sysctl(mib, 2, &oldstate, &oldsize,  &newstate, 4) < 0) {
 120      syslog(LOG_INFO, "cannot mark pid for delayed termination");
 121   }
 122
 123
 124   if (claim_pid_file("/var/run/statd.pid", 0) < 0)
 125     errx(1, "rpc.statd already running");
 126
 127   (void)pmap_unset(SM_PROG, SM_VERS);
 128
 129   transp = svcudp_create(RPC_ANYSOCK);
 130   if (transp == NULL)
 131     errx(1, "cannot create udp service");
 132   if (!svc_register(transp, SM_PROG, SM_VERS, sm_prog_1, IPPROTO_UDP))
 133     errx(1, "unable to register (SM_PROG, SM_VERS, udp)");
 134
 135   transp = svctcp_create(RPC_ANYSOCK, 0, 0);
 136   if (transp == NULL)
 137     errx(1, "cannot create tcp service");
 138   if (!svc_register(transp, SM_PROG, SM_VERS, sm_prog_1, IPPROTO_TCP))
 139     errx(1, "unable to register (SM_PROG, SM_VERS, tcp)");
 140
 141   if (debug) syslog(LOG_INFO, "Starting - debug enabled");
 142   else syslog(LOG_INFO, "Starting");
 143
 144   /* Install signal handler to collect exit status of child processes   */
 145   sa.sa_handler = handle_sigchld;
 146   sigemptyset(&sa.sa_mask);
 147   sigaddset(&sa.sa_mask, SIGCHLD);
 148   sa.sa_flags = SA_RESTART;
 149   sigaction(SIGCHLD, &sa, NULL);
 150
 151   /* Initialisation now complete - start operating                      */
 152   notify_hosts();       /* Forks a process (if necessary) to do the     */
 153                         /* SM_NOTIFY calls, which may be slow.          */
 154
 155   svc_run();    /* Should never return                                  */
 156   exit(1);
 157 }
 158
 159 static void
 160 usage()
 161 {
 162       fprintf(stderr, "usage: rpc.statd [-dn]\n");
 163       exit(1);
 164 }
 165
 166 /* handle_sigchld ---------------------------------------------------------- */
 167 /*
 168    Purpose:     Catch SIGCHLD and collect process status
 169    Returns:     Nothing.
 170    Notes:       No special action required, other than to collect the
 171                 process status and hence allow the child to die:
 172                 we only use child processes for asynchronous transmission
 173                 of SM_NOTIFY to other systems, so it is normal for the
 174                 children to exit when they have done their work.
 175 */
 176
 177 static void handle_sigchld(int sig __unused)
 178 {
 179   int pid, status;
 180   pid = wait4(-1, &status, WNOHANG, (struct rusage*)0);
 181   if (!pid) syslog(LOG_ERR, "Phantom SIGCHLD??");
 182   else if (status == 0)
 183   {
 184     if (debug) syslog(LOG_DEBUG, "Child %d exited OK", pid);
 185   }
 186   else syslog(LOG_ERR, "Child %d failed with status %d", pid,
 187     WEXITSTATUS(status));
 188 }
 189
 190
 191 /* claim_pid_file ---------------------------------------------------------- */
 192 /*
 193    Purpose:     take ownership of and store pid in given pid_file
 194    Returns:     0 on success or -1 on failure
 195    Notes:       force parameter requests that current owner (if any) of
 196                 pid file be terminated.
 197 */
 198
 199 int
 200 claim_pid_file(const char *name, int force)
 201 {
 202   int pidfd, rv, retried = 0;
 203   FILE *pidfile;
 204
 205 try_again:
 206
 207   /* attempt exclusive open of pid file */
 208   pidfd = open(name, O_EXCL|O_CREAT|O_WRONLY,
 209                S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH);
 210   if (pidfd < 0) {
 211     char buf[16];
 212     pid_t pid;
 213     if (retried)
 214       return -1;
 215     bzero(buf, 16);
 216     retried = 1;
 217     /* pid file busy, check validity */
 218     pidfd = open(name, O_RDONLY);
 219     if (pidfd < 0)
 220       goto try_again;
 221     rv = read(pidfd, buf, 15);
 222     close(pidfd);
 223     if (rv <= 0)
 224       goto try_again;
 225     pid = atoi(buf);
 226     if (pid <= 0)
 227       goto try_again;
 228     rv = kill(pid, force ? SIGKILL : 0);
 229     /* if can't signal, assume stale pid file */
 230     if ((rv < 0) || force)
 231       unlink(name);
 232     goto try_again;
 233   }
 234   pid_file = name;
 235   atexit(cleanup_pid_file);
 236
 237   pidfile = fdopen(pidfd, "w");
 238   if (pidfile) {
 239     fchmod(pidfd, S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH);
 240     fprintf(pidfile, "%d\n", getpid());
 241     fclose(pidfile);
 242   } else
 243     perror("fdopen");
 244   close(pidfd);
 245   return 0;
 246 }
 247
 248
 249 /* cleanup_pid_file -------------------------------------------------------- */
 250 /*
 251    Purpose:     delete any pid_file that has been claimed
 252    Returns:     Nothing
 253 */
 254
 255 void
 256 cleanup_pid_file(void)
 257 {
 258   if (pid_file) {
 259     unlink(pid_file);
 260     pid_file = NULL;
 261   }
 262 }
 263
 264
 265 /* handle_sig_cleanup ------------------------------------------------------ */
 266 /*
 267    Purpose:     call pid file cleanup function on signal
 268    Returns:     Nothing
 269 */
 270
 271 static void
 272 handle_sig_cleanup(int sig __unused)
 273 {
 274   cleanup_pid_file();
 275   exit(1);
 276 }
 277