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

   1 /* dnsmasq is Copyright (c) 2000-2013 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) && lease->last_interface == context->if_index)
  42       {
  43         struct in6_addr addr = context->start6;
  44         if (lease->hwaddr_len == 6 &&
  45             (lease->hwaddr_type == ARPHRD_ETHER || lease->hwaddr_type == ARPHRD_IEEE802))
  46           {
  47             /* convert MAC address to EUI-64 */
  48             memcpy(&addr.s6_addr[8], lease->hwaddr, 3);
  49             memcpy(&addr.s6_addr[13], &lease->hwaddr[3], 3);
  50             addr.s6_addr[11] = 0xff;
  51             addr.s6_addr[12] = 0xfe;
  52           }
  53 #if defined(ARPHRD_EUI64)
  54         else if (lease->hwaddr_len == 8 &&
  55                  lease->hwaddr_type == ARPHRD_EUI64)
  56           memcpy(&addr.s6_addr[8], lease->hwaddr, 8);
  57 #endif
  58 #if defined(ARPHRD_IEEE1394) && defined(ARPHRD_EUI64)
  59         else if (lease->clid_len == 9 &&
  60                  lease->clid[0] ==  ARPHRD_EUI64 &&
  61                  lease->hwaddr_type == ARPHRD_IEEE1394)
  62           /* firewire has EUI-64 identifier as clid */
  63           memcpy(&addr.s6_addr[8], &lease->clid[1], 8);
  64 #endif
  65         else
  66           continue;
  67
  68         addr.s6_addr[8] ^= 0x02;
  69
  70         /* check if we already have this one */
  71         for (up = &old, slaac = old; slaac; slaac = slaac->next)
  72           {
  73             if (IN6_ARE_ADDR_EQUAL(&addr, &slaac->addr))
  74               {
  75                 *up = slaac->next;
  76                 /* recheck when DHCPv4 goes through init-reboot */
  77                 if (force)
  78                   {
  79                     slaac->ping_time = now;
  80                     slaac->backoff = 1;
  81                     dns_dirty = 1;
  82                   }
  83                 break;
  84               }
  85             up = &slaac->next;
  86           }
  87
  88         /* No, make new one */
  89         if (!slaac && (slaac = whine_malloc(sizeof(struct slaac_address))))
  90           {
  91             slaac->ping_time = now;
  92             slaac->backoff = 1;
  93             slaac->addr = addr;
  94             slaac->local = context->local6;
  95             /* Do RA's to prod it */
  96             ra_start_unsolicted(now, context);
  97           }
  98
  99         if (slaac)
 100           {
 101             slaac->next = lease->slaac_address;
 102             lease->slaac_address = slaac;
 103           }
 104       }
 105
 106   if (old || dns_dirty)
 107     lease_update_dns(1);
 108
 109   /* Free any no reused */
 110   for (; old; old = slaac)
 111     {
 112       slaac = old->next;
 113       free(old);
 114     }
 115 }
 116
 117
 118 time_t periodic_slaac(time_t now, struct dhcp_lease *leases)
 119 {
 120   struct dhcp_context *context;
 121   struct dhcp_lease *lease;
 122   struct slaac_address *slaac;
 123   time_t next_event = 0;
 124
 125   for (context = daemon->dhcp6; context; context = context->next)
 126     if ((context->flags & CONTEXT_RA_NAME))
 127       break;
 128
 129   /* nothing configured */
 130   if (!context)
 131     return 0;
 132
 133   while (ping_id == 0)
 134     ping_id = rand16();
 135
 136   for (lease = leases; lease; lease = lease->next)
 137     for (slaac = lease->slaac_address; slaac; slaac = slaac->next)
 138       {
 139         /* confirmed or given up? */
 140         if (slaac->backoff == 0 || slaac->ping_time == 0)
 141           continue;
 142
 143         if (difftime(slaac->ping_time, now) <= 0.0)
 144           {
 145             struct ping_packet *ping;
 146             struct sockaddr_in6 addr;
 147
 148             save_counter(0);
 149             ping = expand(sizeof(struct ping_packet));
 150             ping->type = ICMP6_ECHO_REQUEST;
 151             ping->code = 0;
 152             ping->identifier = ping_id;
 153             ping->sequence_no = slaac->backoff;
 154
 155             memset(&addr, 0, sizeof(addr));
 156 #ifdef HAVE_SOCKADDR_SA_LEN
 157             addr.sin6_len = sizeof(struct sockaddr_in6);
 158 #endif
 159             addr.sin6_family = AF_INET6;
 160             addr.sin6_port = htons(IPPROTO_ICMPV6);
 161             addr.sin6_addr = slaac->addr;
 162
 163             if (sendto(daemon->icmp6fd, daemon->outpacket.iov_base, save_counter(0), 0,
 164                        (struct sockaddr *)&addr,  sizeof(addr)) == -1 &&
 165                 errno == EHOSTUNREACH)
 166               slaac->ping_time = 0; /* Give up */
 167             else
 168               {
 169                 slaac->ping_time += (1 << (slaac->backoff - 1)) + (rand16()/21785); /* 0 - 3 */
 170                 if (slaac->backoff > 4)
 171                   slaac->ping_time += rand16()/4000; /* 0 - 15 */
 172                 if (slaac->backoff < 12)
 173                   slaac->backoff++;
 174               }
 175           }
 176
 177         if (slaac->ping_time != 0 &&
 178             (next_event == 0 || difftime(next_event, slaac->ping_time) >= 0.0))
 179           next_event = slaac->ping_time;
 180       }
 181
 182   return next_event;
 183 }
 184
 185
 186 void slaac_ping_reply(struct in6_addr *sender, unsigned char *packet, char *interface, struct dhcp_lease *leases)
 187 {
 188   struct dhcp_lease *lease;
 189   struct slaac_address *slaac;
 190   struct ping_packet *ping = (struct ping_packet *)packet;
 191   int gotone = 0;
 192
 193   if (ping->identifier == ping_id)
 194     for (lease = leases; lease; lease = lease->next)
 195       for (slaac = lease->slaac_address; slaac; slaac = slaac->next)
 196         if (slaac->backoff != 0 && IN6_ARE_ADDR_EQUAL(sender, &slaac->addr))
 197           {
 198             slaac->backoff = 0;
 199             gotone = 1;
 200             inet_ntop(AF_INET6, sender, daemon->addrbuff, ADDRSTRLEN);
 201 #ifdef HAVE_QUIET_DHCP
 202   if (!option_bool(OPT_QUIET_DHCP6))
 203 #endif
 204             my_syslog(MS_DHCP | LOG_INFO, "SLAAC-CONFIRM(%s) %s %s", interface, daemon->addrbuff, lease->hostname);
 205           }
 206
 207   lease_update_dns(gotone);
 208 }
 209
 210 #endif