contrib/ntpd/ntpd.c

   1 /*      $OpenBSD: src/usr.sbin/ntpd/ntpd.c,v 1.35 2005/04/18 20:46:02 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 <errno.h>
  24 #include <poll.h>
  25 #include <pwd.h>
  26 #include <resolv.h>
  27 #include <signal.h>
  28 #include <stdio.h>
  29 #include <stdlib.h>
  30 #include <string.h>
  31 #include <unistd.h>
  32
  33 #include "ntpd.h"
  34
  35 void            sighdlr(int);
  36 __dead void     usage(void);
  37 int             main(int, char *[]);
  38 int             check_child(pid_t, const char *);
  39 int             dispatch_imsg(struct ntpd_conf *);
  40 void            ntpd_adjtime(double);
  41 void            ntpd_settime(double);
  42
  43 volatile sig_atomic_t    quit = 0;
  44 volatile sig_atomic_t    reconfig = 0;
  45 volatile sig_atomic_t    sigchld = 0;
  46 struct imsgbuf          *ibuf;
  47
  48 void
  49 sighdlr(int sig)
  50 {
  51         switch (sig) {
  52         case SIGTERM:
  53         case SIGINT:
  54                 quit = 1;
  55                 break;
  56         case SIGCHLD:
  57                 sigchld = 1;
  58                 break;
  59         case SIGHUP:
  60                 reconfig = 1;
  61                 break;
  62         }
  63 }
  64
  65 __dead void
  66 usage(void)
  67 {
  68         extern char *__progname;
  69
  70         fprintf(stderr, "usage: %s [-dSs] [-f file]\n", __progname);
  71         exit(1);
  72 }
  73
  74 #define POLL_MAX                8
  75 #define PFD_PIPE                0
  76
  77 int
  78 main(int argc, char *argv[])
  79 {
  80         struct ntpd_conf         conf;
  81         struct pollfd            pfd[POLL_MAX];
  82         pid_t                    chld_pid = 0, pid;
  83         const char              *conffile;
  84         int                      ch, nfds, timeout = INFTIM;
  85         int                      pipe_chld[2];
  86
  87         conffile = CONFFILE;
  88
  89         bzero(&conf, sizeof(conf));
  90
  91         log_init(1);            /* log to stderr until daemonized */
  92         res_init();             /* XXX */
  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                         conf.settime = 0;
 169                         timeout = INFTIM;
 170                         log_init(conf.debug);
 171                         log_debug("no reply received, skipping initial time "
 172                             "setting");
 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                                 fatalx("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                                 fatalx("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 < 1 + IMSG_HEADER_SIZE)
 286                                 fatalx("invalid IMSG_HOST_DNS received");
 287                         imsg.hdr.len -= 1 + IMSG_HEADER_SIZE;
 288                         if (name[imsg.hdr.len] != '\0' ||
 289                             strlen(name) != imsg.hdr.len)
 290                                 fatalx("invalid IMSG_HOST_DNS received");
 291                         if ((cnt = host_dns(name, &hn)) > 0) {
 292                                 buf = imsg_create(ibuf, IMSG_HOST_DNS,
 293                                     imsg.hdr.peerid, 0,
 294                                     cnt * sizeof(struct sockaddr_storage));
 295                                 if (buf == NULL)
 296                                         break;
 297                                 for (h = hn; h != NULL; h = h->next) {
 298                                         imsg_add(buf, &h->ss, sizeof(h->ss));
 299                                 }
 300                                 imsg_close(ibuf, buf);
 301                         }
 302                         break;
 303                 default:
 304                         break;
 305                 }
 306                 imsg_free(&imsg);
 307         }
 308         return (0);
 309 }
 310
 311 void
 312 ntpd_adjtime(double d)
 313 {
 314         struct timeval  tv;
 315
 316         if (d >= (double)LOG_NEGLIGEE / 1000 ||
 317             d <= -1 * (double)LOG_NEGLIGEE / 1000)
 318                 log_info("adjusting local clock by %fs", d);
 319         else
 320                 log_debug("adjusting local clock by %fs", d);
 321         d_to_tv(d, &tv);
 322         if (adjtime(&tv, NULL) == -1)
 323                 log_warn("adjtime failed");
 324 }
 325
 326 void
 327 ntpd_settime(double d)
 328 {
 329         struct timeval  tv, curtime;
 330         char            buf[80];
 331         time_t          tval;
 332
 333         /* if the offset is small, don't call settimeofday */
 334         if (d < SETTIME_MIN_OFFSET && d > -SETTIME_MIN_OFFSET)
 335                 return;
 336
 337         if (gettimeofday(&curtime, NULL) == -1) {
 338                 log_warn("gettimeofday");
 339                 return;
 340         }
 341         d_to_tv(d, &tv);
 342         curtime.tv_usec += tv.tv_usec + 1000000;
 343         curtime.tv_sec += tv.tv_sec - 1 + (curtime.tv_usec / 1000000);
 344         curtime.tv_usec %= 1000000;
 345
 346         if (settimeofday(&curtime, NULL) == -1) {
 347                 log_warn("settimeofday");
 348                 return;
 349         }
 350         tval = curtime.tv_sec;
 351         strftime(buf, sizeof(buf), "%a %b %e %H:%M:%S %Z %Y",
 352             localtime(&tval));
 353         log_info("set local clock to %s (offset %fs)", buf, d);
 354 }