contrib/ntpd/ntpd.c

   1 /*      $OpenBSD: ntpd.c,v 1.28 2005/01/28 12:32:24 henning Exp $ */
   2
   3 /*
   4  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
   5  *
   6  * Permission to use, copy, modify, and distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
  15  * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
  16  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 #include <sys/types.h>
  20 #include <sys/socket.h>
  21 #include <sys/wait.h>
  22 #include <netinet/in.h>
  23 #include <arpa/inet.h>
  24 #include <errno.h>
  25 #include <fcntl.h>
  26 #include <poll.h>
  27 #include <pwd.h>
  28 #include <signal.h>
  29 #include <stdio.h>
  30 #include <stdlib.h>
  31 #include <string.h>
  32 #include <unistd.h>
  33
  34 #include "ntpd.h"
  35
  36 void            sighdlr(int);
  37 __dead void     usage(void);
  38 int             main(int, char *[]);
  39 int             check_child(pid_t, const char *);
  40 int             dispatch_imsg(struct ntpd_conf *);
  41 void            ntpd_adjtime(double);
  42 void            ntpd_settime(double);
  43
  44 volatile sig_atomic_t    quit = 0;
  45 volatile sig_atomic_t    reconfig = 0;
  46 volatile sig_atomic_t    sigchld = 0;
  47 struct imsgbuf          *ibuf;
  48
  49 void
  50 sighdlr(int sig)
  51 {
  52         switch (sig) {
  53         case SIGTERM:
  54         case SIGINT:
  55                 quit = 1;
  56                 break;
  57         case SIGCHLD:
  58                 sigchld = 1;
  59                 break;
  60         case SIGHUP:
  61                 reconfig = 1;
  62                 break;
  63         }
  64 }
  65
  66 __dead void
  67 usage(void)
  68 {
  69         extern char *__progname;
  70
  71         fprintf(stderr, "usage: %s [-dSs] [-f file]\n", __progname);
  72         exit(1);
  73 }
  74
  75 #define POLL_MAX                8
  76 #define PFD_PIPE                0
  77
  78 int
  79 main(int argc, char *argv[])
  80 {
  81         struct ntpd_conf         conf;
  82         struct pollfd            pfd[POLL_MAX];
  83         pid_t                    chld_pid = 0, pid;
  84         const char              *conffile;
  85         int                      ch, nfds, timeout = INFTIM;
  86         int                      pipe_chld[2];
  87
  88         conffile = CONFFILE;
  89
  90         bzero(&conf, sizeof(conf));
  91
  92         log_init(1);            /* log to stderr until daemonized */
  93
  94         while ((ch = getopt(argc, argv, "df:sS")) != -1) {
  95                 switch (ch) {
  96                 case 'd':
  97                         conf.debug = 1;
  98                         break;
  99                 case 'f':
 100                         conffile = optarg;
 101                         break;
 102                 case 's':
 103                         conf.settime = 1;
 104                         break;
 105                 case 'S':
 106                         conf.settime = 0;
 107                         break;
 108                 default:
 109                         usage();
 110                         /* NOTREACHED */
 111                 }
 112         }
 113
 114         if (parse_config(conffile, &conf))
 115                 exit(1);
 116
 117         if (geteuid()) {
 118                 fprintf(stderr, "ntpd: need root privileges\n");
 119                 exit(1);
 120         }
 121
 122         if (getpwnam(NTPD_USER) == NULL) {
 123                 fprintf(stderr, "ntpd: unknown user %s\n", NTPD_USER);
 124                 exit(1);
 125         }
 126         endpwent();
 127
 128         if (!conf.settime) {
 129                 log_init(conf.debug);
 130                 if (!conf.debug)
 131                         if (daemon(1, 0))
 132                                 fatal("daemon");
 133         } else
 134                 timeout = 15 * 1000;
 135
 136         if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe_chld) == -1)
 137                 fatal("socketpair");
 138
 139         /* fork child process */
 140         chld_pid = ntp_main(pipe_chld, &conf);
 141
 142         setproctitle("[priv]");
 143
 144         signal(SIGTERM, sighdlr);
 145         signal(SIGINT, sighdlr);
 146         signal(SIGCHLD, sighdlr);
 147         signal(SIGHUP, sighdlr);
 148
 149         close(pipe_chld[1]);
 150
 151         if ((ibuf = malloc(sizeof(struct imsgbuf))) == NULL)
 152                 fatal(NULL);
 153         imsg_init(ibuf, pipe_chld[0]);
 154
 155         while (quit == 0) {
 156                 pfd[PFD_PIPE].fd = ibuf->fd;
 157                 pfd[PFD_PIPE].events = POLLIN;
 158                 if (ibuf->w.queued)
 159                         pfd[PFD_PIPE].events |= POLLOUT;
 160
 161                 if ((nfds = poll(pfd, 1, timeout)) == -1)
 162                         if (errno != EINTR) {
 163                                 log_warn("poll error");
 164                                 quit = 1;
 165                         }
 166
 167                 if (nfds == 0 && conf.settime) {
 168                         log_debug("no reply received, skipping initial time "
 169                             "setting");
 170                         conf.settime = 0;
 171                         timeout = INFTIM;
 172                         log_init(conf.debug);
 173                         if (!conf.debug)
 174                                 if (daemon(1, 0))
 175                                         fatal("daemon");
 176                 }
 177
 178                 if (nfds > 0 && (pfd[PFD_PIPE].revents & POLLOUT))
 179                         if (msgbuf_write(&ibuf->w) < 0) {
 180                                 log_warn("pipe write error (to child)");
 181                                 quit = 1;
 182                         }
 183
 184                 if (nfds > 0 && pfd[PFD_PIPE].revents & POLLIN) {
 185                         nfds--;
 186                         if (dispatch_imsg(&conf) == -1)
 187                                 quit = 1;
 188                 }
 189
 190                 if (sigchld) {
 191                         if (check_child(chld_pid, "child")) {
 192                                 quit = 1;
 193                                 chld_pid = 0;
 194                         }
 195                         sigchld = 0;
 196                 }
 197
 198         }
 199
 200         signal(SIGCHLD, SIG_DFL);
 201
 202         if (chld_pid)
 203                 kill(chld_pid, SIGTERM);
 204
 205         do {
 206                 if ((pid = wait(NULL)) == -1 &&
 207                     errno != EINTR && errno != ECHILD)
 208                         fatal("wait");
 209         } while (pid != -1 || (pid == -1 && errno == EINTR));
 210
 211         msgbuf_clear(&ibuf->w);
 212         free(ibuf);
 213         log_info("Terminating");
 214         return (0);
 215 }
 216
 217 int
 218 check_child(pid_t pid, const char *pname)
 219 {
 220         int     status;
 221
 222         if (waitpid(pid, &status, WNOHANG) > 0) {
 223                 if (WIFEXITED(status)) {
 224                         log_warnx("Lost child: %s exited", pname);
 225                         return (1);
 226                 }
 227                 if (WIFSIGNALED(status)) {
 228                         log_warnx("Lost child: %s terminated; signal %d",
 229                             pname, WTERMSIG(status));
 230                         return (1);
 231                 }
 232         }
 233
 234         return (0);
 235 }
 236
 237 int
 238 dispatch_imsg(struct ntpd_conf *conf)
 239 {
 240         struct imsg              imsg;
 241         int                      n, cnt;
 242         double                   d;
 243         char                    *name;
 244         struct ntp_addr         *h, *hn;
 245         struct buf              *buf;
 246
 247         if ((n = imsg_read(ibuf)) == -1)
 248                 return (-1);
 249
 250         if (n == 0) {   /* connection closed */
 251                 log_warnx("dispatch_imsg in main: pipe closed");
 252                 return (-1);
 253         }
 254
 255         for (;;) {
 256                 if ((n = imsg_get(ibuf, &imsg)) == -1)
 257                         return (-1);
 258
 259                 if (n == 0)
 260                         break;
 261
 262                 switch (imsg.hdr.type) {
 263                 case IMSG_ADJTIME:
 264                         if (imsg.hdr.len != IMSG_HEADER_SIZE + sizeof(d))
 265                                 fatal("invalid IMSG_ADJTIME received");
 266                         memcpy(&d, imsg.data, sizeof(d));
 267                         ntpd_adjtime(d);
 268                         break;
 269                 case IMSG_SETTIME:
 270                         if (imsg.hdr.len != IMSG_HEADER_SIZE + sizeof(d))
 271                                 fatal("invalid IMSG_SETTIME received");
 272                         if (!conf->settime)
 273                                 break;
 274                         memcpy(&d, imsg.data, sizeof(d));
 275                         ntpd_settime(d);
 276                         /* daemonize now */
 277                         log_init(conf->debug);
 278                         if (!conf->debug)
 279                                 if (daemon(1, 0))
 280                                         fatal("daemon");
 281                         conf->settime = 0;
 282                         break;
 283                 case IMSG_HOST_DNS:
 284                         name = imsg.data;
 285                         if (imsg.hdr.len != strlen(name) + 1 + IMSG_HEADER_SIZE)
 286                                 fatal("invalid IMSG_HOST_DNS received");
 287                         if ((cnt = host_dns(name, &hn)) > 0) {
 288                                 buf = imsg_create(ibuf, IMSG_HOST_DNS,
 289                                     imsg.hdr.peerid, 0,
 290                                     cnt * sizeof(struct sockaddr_storage));
 291                                 if (buf == NULL)
 292                                         break;
 293                                 for (h = hn; h != NULL; h = h->next) {
 294                                         imsg_add(buf, &h->ss, sizeof(h->ss));
 295                                 }
 296                                 imsg_close(ibuf, buf);
 297                         }
 298                         break;
 299                 default:
 300                         break;
 301                 }
 302                 imsg_free(&imsg);
 303         }
 304         return (0);
 305 }
 306
 307 void
 308 ntpd_adjtime(double d)
 309 {
 310         struct timeval  tv;
 311
 312         if (d >= (double)LOG_NEGLIGEE / 1000 ||
 313             d <= -1 * (double)LOG_NEGLIGEE / 1000)
 314                 log_info("adjusting local clock by %fs", d);
 315         else
 316                 log_debug("adjusting local clock by %fs", d);
 317         d_to_tv(d, &tv);
 318         if (adjtime(&tv, NULL) == -1)
 319                 log_warn("adjtime failed");
 320 }
 321
 322 void
 323 ntpd_settime(double d)
 324 {
 325         struct timeval  tv, curtime;
 326         char            buf[80];
 327         time_t          tval;
 328
 329         /* if the offset is small, don't call settimeofday */
 330         if (d < SETTIME_MIN_OFFSET && d > -SETTIME_MIN_OFFSET)
 331                 return;
 332
 333         d_to_tv(d, &tv);
 334         if (gettimeofday(&curtime, NULL) == -1)
 335                 log_warn("gettimeofday");
 336         curtime.tv_sec += tv.tv_sec;
 337         curtime.tv_usec += tv.tv_usec;
 338         if (curtime.tv_usec > 1000000) {
 339                 curtime.tv_sec++;
 340                 curtime.tv_usec -= 1000000;
 341         }
 342         if (settimeofday(&curtime, NULL) == -1)
 343                 log_warn("settimeofday");
 344         tval = curtime.tv_sec;
 345         strftime(buf, sizeof(buf), "%a %b %e %H:%M:%S %Z %Y",
 346             localtime(&tval));
 347         log_info("set local clock to %s (offset %fs)", buf, d);
 348 }