external/bsd/dhcpcd/dist/bind.c

   1 /*
   2  * dhcpcd - DHCP client daemon
   3  * Copyright (c) 2006-2009 Roy Marples <roy@marples.name>
   4  * All rights reserved
   5
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  25  * SUCH DAMAGE.
  26  */
  27
  28 #include <sys/param.h>
  29 #include <sys/time.h>
  30
  31 #include <fcntl.h>
  32 #ifdef BSD
  33 #  include <paths.h>
  34 #endif
  35 #include <signal.h>
  36 #include <stdlib.h>
  37 #include <syslog.h>
  38 #include <unistd.h>
  39
  40 #include "arp.h"
  41 #include "bind.h"
  42 #include "common.h"
  43 #include "configure.h"
  44 #include "dhcpcd.h"
  45 #include "eloop.h"
  46 #include "if-options.h"
  47 #include "net.h"
  48 #include "signals.h"
  49
  50 #ifndef _PATH_DEVNULL
  51 #  define _PATH_DEVNULL "/dev/null"
  52 #endif
  53
  54 /* We do things after aquiring the lease, so ensure we have enough time for them */
  55 #define DHCP_MIN_LEASE 20
  56
  57 #ifndef THERE_IS_NO_FORK
  58 pid_t
  59 daemonise(void)
  60 {
  61         pid_t pid;
  62         sigset_t full;
  63         sigset_t old;
  64         char buf = '\0';
  65         int sidpipe[2], fd;
  66
  67         if (options & DHCPCD_DAEMONISED || !(options & DHCPCD_DAEMONISE))
  68                 return 0;
  69         sigfillset(&full);
  70         sigprocmask(SIG_SETMASK, &full, &old);
  71         /* Setup a signal pipe so parent knows when to exit. */
  72         if (pipe(sidpipe) == -1) {
  73                 syslog(LOG_ERR, "pipe: %m");
  74                 return -1;
  75         }
  76         syslog(LOG_INFO, "forking to background");
  77         switch (pid = fork()) {
  78         case -1:
  79                 syslog(LOG_ERR, "fork: %m");
  80                 exit(EXIT_FAILURE);
  81                 /* NOTREACHED */
  82         case 0:
  83                 setsid();
  84                 /* Notify parent it's safe to exit as we've detached. */
  85                 close(sidpipe[0]);
  86                 if (write(sidpipe[1], &buf, 1) == -1)
  87                         syslog(LOG_ERR, "failed to notify parent: %m");
  88                 close(sidpipe[1]);
  89                 if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
  90                         dup2(fd, STDIN_FILENO);
  91                         dup2(fd, STDOUT_FILENO);
  92                         dup2(fd, STDERR_FILENO);
  93                         if (fd > STDERR_FILENO)
  94                                 close(fd);
  95                 }
  96                 break;
  97         default:
  98                 signal_reset();
  99                 /* Wait for child to detach */
 100                 close(sidpipe[1]);
 101                 if (read(sidpipe[0], &buf, 1) == -1)
 102                         syslog(LOG_ERR, "failed to read child: %m");
 103                 close(sidpipe[0]);
 104                 break;
 105         }
 106         /* Done with the fd now */
 107         if (pid != 0) {
 108                 writepid(pidfd, pid);
 109                 close(pidfd);
 110                 pidfd = -1;
 111                 exit(EXIT_SUCCESS);
 112         }
 113         options |= DHCPCD_DAEMONISED;
 114         sigprocmask(SIG_SETMASK, &old, NULL);
 115         return pid;
 116 }
 117 #endif
 118
 119 void
 120 bind_interface(void *arg)
 121 {
 122         struct interface *iface = arg;
 123         struct if_state *state = iface->state;
 124         struct if_options *ifo = state->options;
 125         struct dhcp_lease *lease = &state->lease;
 126         struct timeval tv;
 127
 128         /* We're binding an address now - ensure that sockets are closed */
 129         close_sockets(iface);
 130         state->reason = NULL;
 131         delete_timeout(handle_exit_timeout, NULL);
 132         if (clock_monotonic)
 133                 get_monotonic(&lease->boundtime);
 134         state->xid = 0;
 135         free(state->old);
 136         state->old = state->new;
 137         state->new = state->offer;
 138         state->offer = NULL;
 139         get_lease(lease, state->new);
 140         if (ifo->options & DHCPCD_STATIC) {
 141                 syslog(LOG_INFO, "%s: using static address %s",
 142                     iface->name, inet_ntoa(lease->addr));
 143                 lease->leasetime = ~0U;
 144                 lease->net.s_addr = ifo->req_mask.s_addr;
 145                 state->reason = "STATIC";
 146         } else if (IN_LINKLOCAL(htonl(state->new->yiaddr))) {
 147                 syslog(LOG_INFO, "%s: using IPv4LL address %s",
 148                     iface->name, inet_ntoa(lease->addr));
 149                 lease->leasetime = ~0U;
 150                 state->reason = "IPV4LL";
 151         } else if (ifo->options & DHCPCD_INFORM) {
 152                 if (ifo->req_addr.s_addr != 0)
 153                         lease->addr.s_addr = ifo->req_addr.s_addr;
 154                 else
 155                         lease->addr.s_addr = iface->addr.s_addr;
 156                 syslog(LOG_INFO, "%s: received approval for %s", iface->name,
 157                     inet_ntoa(lease->addr));
 158                 lease->leasetime = ~0U;
 159                 state->reason = "INFORM";
 160         } else {
 161                 if (gettimeofday(&tv, NULL) == 0)
 162                         lease->leasedfrom = tv.tv_sec;
 163                 else if (lease->frominfo)
 164                         state->reason = "TIMEOUT";
 165                 if (lease->leasetime == ~0U) {
 166                         lease->renewaltime =
 167                             lease->rebindtime =
 168                             lease->leasetime;
 169                         syslog(LOG_INFO, "%s: leased %s for infinity",
 170                             iface->name, inet_ntoa(lease->addr));
 171                 } else {
 172                         if (lease->leasetime < DHCP_MIN_LEASE) {
 173                                 syslog(LOG_WARNING,
 174                                     "%s: minimum lease is %d seconds",
 175                                     iface->name, DHCP_MIN_LEASE);
 176                                 lease->leasetime = DHCP_MIN_LEASE;
 177                         }
 178                         if (lease->rebindtime == 0)
 179                                 lease->rebindtime = lease->leasetime * T2;
 180                         else if (lease->rebindtime >= lease->leasetime) {
 181                                 lease->rebindtime = lease->leasetime * T2;
 182                                 syslog(LOG_ERR,
 183                                     "%s: rebind time greater than lease "
 184                                     "time, forcing to %u seconds",
 185                                     iface->name, lease->rebindtime);
 186                         }
 187                         if (lease->renewaltime == 0)
 188                                 lease->renewaltime = lease->leasetime * T1;
 189                         else if (lease->renewaltime > lease->rebindtime) {
 190                                 lease->renewaltime = lease->leasetime * T1;
 191                                 syslog(LOG_ERR,
 192                                     "%s: renewal time greater than rebind "
 193                                     "time, forcing to %u seconds",
 194                                     iface->name, lease->renewaltime);
 195                         }
 196                         syslog(LOG_INFO,
 197                             "%s: leased %s for %u seconds", iface->name,
 198                             inet_ntoa(lease->addr), lease->leasetime);
 199                 }
 200         }
 201         if (options & DHCPCD_TEST) {
 202                 state->reason = "TEST";
 203                 run_script(iface);
 204                 exit(EXIT_SUCCESS);
 205         }
 206         if (state->reason == NULL) {
 207                 if (state->old) {
 208                         if (state->old->yiaddr == state->new->yiaddr &&
 209                             lease->server.s_addr)
 210                                 state->reason = "RENEW";
 211                         else
 212                                 state->reason = "REBIND";
 213                 } else if (state->state == DHS_REBOOT)
 214                         state->reason = "REBOOT";
 215                 else
 216                         state->reason = "BOUND";
 217         }
 218         if (lease->leasetime == ~0U)
 219                 lease->renewaltime = lease->rebindtime = lease->leasetime;
 220         else {
 221                 add_timeout_sec(lease->renewaltime, start_renew, iface);
 222                 add_timeout_sec(lease->rebindtime, start_rebind, iface);
 223                 add_timeout_sec(lease->leasetime, start_expire, iface);
 224         }
 225         ifo->options &= ~ DHCPCD_CSR_WARNED;
 226         configure(iface);
 227         daemonise();
 228         state->state = DHS_BOUND;
 229         if (ifo->options & DHCPCD_ARP) {
 230                 state->claims = 0;
 231                 send_arp_announce(iface);
 232         }
 233 }