release/src/router/dnsmasq/src/slaac.c

   1 /* dnsmasq is Copyright (c) 2000-2015 Simon Kelley
   2
   3    This program is free software; you can redistribute it and/or modify
   4    it under the terms of the GNU General Public License as published by
   5    the Free Software Foundation; version 2 dated June, 1991, or
   6    (at your option) version 3 dated 29 June, 2007.
   7
   8    This program is distributed in the hope that it will be useful,
   9    but WITHOUT ANY WARRANTY; without even the implied warranty of
  10    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11    GNU General Public License for more details.
  12
  13    You should have received a copy of the GNU General Public License
  14    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15 */
  16
  17 #include "dnsmasq.h"
  18
  19 #ifdef HAVE_DHCP6
  20
  21 #include <netinet/icmp6.h>
  22
  23 static int ping_id = 0;
  24
  25 void slaac_add_addrs(struct dhcp_lease *lease, time_t now, int force)
  26 {
  27   struct slaac_address *slaac, *old, **up;
  28   struct dhcp_context *context;
  29   int dns_dirty = 0;
  30
  31   if (!(lease->flags & LEASE_HAVE_HWADDR) ||
  32       (lease->flags & (LEASE_TA | LEASE_NA)) ||
  33       lease->last_interface == 0 ||
  34       !lease->hostname)
  35     return ;
  36
  37   old = lease->slaac_address;
  38   lease->slaac_address = NULL;
  39
  40   for (context = daemon->dhcp6; context; context = context->next)
  41     if ((context->flags & CONTEXT_RA_NAME) &&
  42         !(context->flags & CONTEXT_OLD) &&
  43         lease->last_interface == context->if_index)
  44       {
  45         struct in6_addr addr = context->start6;
  46         if (lease->hwaddr_len == 6 &&
  47             (lease->hwaddr_type == ARPHRD_ETHER || lease->hwaddr_type == ARPHRD_IEEE802))
  48           {
  49             /* convert MAC address to EUI-64 */
  50             memcpy(&addr.s6_addr[8], lease->hwaddr, 3);
  51             memcpy(&addr.s6_addr[13], &lease->hwaddr[3], 3);
  52             addr.s6_addr[11] = 0xff;
  53             addr.s6_addr[12] = 0xfe;
  54           }
  55 #if defined(ARPHRD_EUI64)
  56         else if (lease->hwaddr_len == 8 &&
  57                  lease->hwaddr_type == ARPHRD_EUI64)
  58           memcpy(&addr.s6_addr[8], lease->hwaddr, 8);
  59 #endif
  60 #if defined(ARPHRD_IEEE1394) && defined(ARPHRD_EUI64)
  61         else if (lease->clid_len == 9 &&
  62                  lease->clid[0] ==  ARPHRD_EUI64 &&
  63                  lease->hwaddr_type == ARPHRD_IEEE1394)
  64           /* firewire has EUI-64 identifier as clid */
  65           memcpy(&addr.s6_addr[8], &lease->clid[1], 8);
  66 #endif
  67         else
  68           continue;
  69
  70         addr.s6_addr[8] ^= 0x02;
  71
  72         /* check if we already have this one */
  73         for (up = &old, slaac = old; slaac; slaac = slaac->next)
  74           {
  75             if (IN6_ARE_ADDR_EQUAL(&addr, &slaac->addr))
  76               {
  77                 *up = slaac->next;
  78                 /* recheck when DHCPv4 goes through init-reboot */
  79                 if (force)
  80                   {
  81                     slaac->ping_time = now;
  82                     slaac->backoff = 1;
  83                     dns_dirty = 1;
  84                   }
  85                 break;
  86               }
  87             up = &slaac->next;
  88           }
  89
  90         /* No, make new one */
  91         if (!slaac && (slaac = whine_malloc(sizeof(struct slaac_address))))
  92           {
  93             slaac->ping_time = now;
  94             slaac->backoff = 1;
  95             slaac->addr = addr;
  96             /* Do RA's to prod it */
  97             ra_start_unsolicted(now, context);
  98           }
  99
 100         if (slaac)
 101           {
 102             slaac->next = lease->slaac_address;
 103             lease->slaac_address = slaac;
 104           }
 105       }
 106
 107   if (old || dns_dirty)
 108     lease_update_dns(1);
 109
 110   /* Free any no reused */
 111   for (; old; old = slaac)
 112     {
 113       slaac = old->next;
 114       free(old);
 115     }
 116 }
 117
 118
 119 time_t periodic_slaac(time_t now, struct dhcp_lease *leases)
 120 {
 121   struct dhcp_context *context;
 122   struct dhcp_lease *lease;
 123   struct slaac_address *slaac;
 124   time_t next_event = 0;
 125
 126   for (context = daemon->dhcp6; context; context = context->next)
 127     if ((context->flags & CONTEXT_RA_NAME) && !(context->flags & CONTEXT_OLD))
 128       break;
 129
 130   /* nothing configured */
 131   if (!context)
 132     return 0;
 133
 134   while (ping_id == 0)
 135     ping_id = rand16();
 136
 137   for (lease = leases; lease; lease = lease->next)
 138     for (slaac = lease->slaac_address; slaac; slaac = slaac->next)
 139       {
 140         /* confirmed or given up? */
 141         if (slaac->backoff == 0 || slaac->ping_time == 0)
 142           continue;
 143
 144         if (difftime(slaac->ping_time, now) <= 0.0)
 145           {
 146             struct ping_packet *ping;
 147             struct sockaddr_in6 addr;
 148
 149             save_counter(0);
 150             ping = expand(sizeof(struct ping_packet));
 151             ping->type = ICMP6_ECHO_REQUEST;
 152             ping->code = 0;
 153             ping->identifier = ping_id;
 154             ping->sequence_no = slaac->backoff;
 155
 156             memset(&addr, 0, sizeof(addr));
 157 #ifdef HAVE_SOCKADDR_SA_LEN
 158             addr.sin6_len = sizeof(struct sockaddr_in6);
 159 #endif
 160             addr.sin6_family = AF_INET6;
 161             addr.sin6_port = htons(IPPROTO_ICMPV6);
 162             addr.sin6_addr = slaac->addr;
 163
 164             if (sendto(daemon->icmp6fd, daemon->outpacket.iov_base, save_counter(0), 0,
 165                        (struct sockaddr *)&addr,  sizeof(addr)) == -1 &&
 166                 errno == EHOSTUNREACH)
 167               slaac->ping_time = 0; /* Give up */
 168             else
 169               {
 170                 slaac->ping_time += (1 << (slaac->backoff - 1)) + (rand16()/21785); /* 0 - 3 */
 171                 if (slaac->backoff > 4)
 172                   slaac->ping_time += rand16()/4000; /* 0 - 15 */
 173                 if (slaac->backoff < 12)
 174                   slaac->backoff++;
 175               }
 176           }
 177
 178         if (slaac->ping_time != 0 &&
 179             (next_event == 0 || difftime(next_event, slaac->ping_time) >= 0.0))
 180           next_event = slaac->ping_time;
 181       }
 182
 183   return next_event;
 184 }
 185
 186
 187 void slaac_ping_reply(struct in6_addr *sender, unsigned char *packet, char *interface, struct dhcp_lease *leases)
 188 {
 189   struct dhcp_lease *lease;
 190   struct slaac_address *slaac;
 191   struct ping_packet *ping = (struct ping_packet *)packet;
 192   int gotone = 0;
 193
 194   if (ping->identifier == ping_id)
 195     for (lease = leases; lease; lease = lease->next)
 196       for (slaac = lease->slaac_address; slaac; slaac = slaac->next)
 197         if (slaac->backoff != 0 && IN6_ARE_ADDR_EQUAL(sender, &slaac->addr))
 198           {
 199             slaac->backoff = 0;
 200             gotone = 1;
 201             inet_ntop(AF_INET6, sender, daemon->addrbuff, ADDRSTRLEN);
 202             if (!option_bool(OPT_QUIET_DHCP6))
 203               my_syslog(MS_DHCP | LOG_INFO, "SLAAC-CONFIRM(%s) %s %s", interface, daemon->addrbuff, lease->hostname);
 204           }
 205
 206   lease_update_dns(gotone);
 207 }
 208
 209 #endif