zebra/irdp_main.c

   1 /*
   2  *
   3  * Copyright (C) 2000  Robert Olsson.
   4  * Swedish University of Agricultural Sciences
   5  *
   6  * This file is part of GNU Zebra.
   7  *
   8  * GNU Zebra is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU General Public License as published by the
  10  * Free Software Foundation; either version 2, or (at your option) any
  11  * later version.
  12  *
  13  * GNU Zebra is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License along
  19  * with this program; see the file COPYING; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 /*
  24  * This work includes work with the following copywrite:
  25  *
  26  * Copyright (C) 1997, 2000 Kunihiro Ishiguro
  27  *
  28  */
  29
  30 /*
  31  * Thanks to Jens Låås at Swedish University of Agricultural Sciences
  32  * for reviewing and tests.
  33  */
  34
  35
  36 #include <zebra.h>
  37
  38 #ifdef HAVE_IRDP
  39
  40 #include "if.h"
  41 #include "vty.h"
  42 #include "sockunion.h"
  43 #include "sockopt.h"
  44 #include "prefix.h"
  45 #include "command.h"
  46 #include "memory.h"
  47 #include "zebra_memory.h"
  48 #include "stream.h"
  49 #include "ioctl.h"
  50 #include "connected.h"
  51 #include "log.h"
  52 #include "zclient.h"
  53 #include "thread.h"
  54 #include "privs.h"
  55 #include "zebra/interface.h"
  56 #include "zebra/rtadv.h"
  57 #include "zebra/rib.h"
  58 #include "zebra/zserv.h"
  59 #include "zebra/redistribute.h"
  60 #include "zebra/irdp.h"
  61 #include <netinet/ip_icmp.h>
  62
  63 #include "checksum.h"
  64 #include "if.h"
  65 #include "sockunion.h"
  66 #include "log.h"
  67
  68 /* GLOBAL VARS */
  69
  70 extern struct zebra_privs_t zserv_privs;
  71
  72 struct thread *t_irdp_raw;
  73
  74 /* Timer interval of irdp. */
  75 int irdp_timer_interval = IRDP_DEFAULT_INTERVAL;
  76
  77 int irdp_sock_init(void)
  78 {
  79         int ret, i;
  80         int save_errno;
  81         int sock;
  82
  83         if (zserv_privs.change(ZPRIVS_RAISE))
  84                 zlog_err("irdp_sock_init: could not raise privs, %s",
  85                          safe_strerror(errno));
  86
  87         sock = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP);
  88         save_errno = errno;
  89
  90         if (zserv_privs.change(ZPRIVS_LOWER))
  91                 zlog_err("irdp_sock_init: could not lower privs, %s",
  92                          safe_strerror(errno));
  93
  94         if (sock < 0) {
  95                 zlog_warn("IRDP: can't create irdp socket %s",
  96                           safe_strerror(save_errno));
  97                 return sock;
  98         };
  99
 100         i = 1;
 101         ret = setsockopt(sock, IPPROTO_IP, IP_TTL, (void *)&i, sizeof(i));
 102         if (ret < 0) {
 103                 zlog_warn("IRDP: can't do irdp sockopt %s",
 104                           safe_strerror(errno));
 105                 close(sock);
 106                 return ret;
 107         };
 108
 109         ret = setsockopt_ifindex(AF_INET, sock, 1);
 110         if (ret < 0) {
 111                 zlog_warn("IRDP: can't do irdp sockopt %s",
 112                           safe_strerror(errno));
 113                 close(sock);
 114                 return ret;
 115         };
 116
 117         t_irdp_raw = NULL;
 118         thread_add_read(zebrad.master, irdp_read_raw, NULL, sock, &t_irdp_raw);
 119
 120         return sock;
 121 }
 122
 123
 124 static int get_pref(struct irdp_interface *irdp, struct prefix *p)
 125 {
 126         struct listnode *node;
 127         struct Adv *adv;
 128
 129         /* Use default preference or use the override pref */
 130
 131         if (irdp->AdvPrefList == NULL)
 132                 return irdp->Preference;
 133
 134         for (ALL_LIST_ELEMENTS_RO(irdp->AdvPrefList, node, adv))
 135                 if (p->u.prefix4.s_addr == adv->ip.s_addr)
 136                         return adv->pref;
 137
 138         return irdp->Preference;
 139 }
 140
 141 /* Make ICMP Router Advertisement Message. */
 142 static int make_advertisement_packet(struct interface *ifp, struct prefix *p,
 143                                      struct stream *s)
 144 {
 145         struct zebra_if *zi = ifp->info;
 146         struct irdp_interface *irdp = &zi->irdp;
 147         int size;
 148         int pref;
 149         u_int16_t checksum;
 150
 151         pref = get_pref(irdp, p);
 152
 153         stream_putc(s, ICMP_ROUTERADVERT); /* Type. */
 154         stream_putc(s, 0);                 /* Code. */
 155         stream_putw(s, 0);                 /* Checksum. */
 156         stream_putc(s, 1);                 /* Num address. */
 157         stream_putc(s, 2);                 /* Address Entry Size. */
 158
 159         if (irdp->flags & IF_SHUTDOWN)
 160                 stream_putw(s, 0);
 161         else
 162                 stream_putw(s, irdp->Lifetime);
 163
 164         stream_putl(s, htonl(p->u.prefix4.s_addr)); /* Router address. */
 165         stream_putl(s, pref);
 166
 167         /* in_cksum return network byte order value */
 168         size = 16;
 169         checksum = in_cksum(s->data, size);
 170         stream_putw_at(s, 2, htons(checksum));
 171
 172         return size;
 173 }
 174
 175 static void irdp_send(struct interface *ifp, struct prefix *p, struct stream *s)
 176 {
 177         struct zebra_if *zi = ifp->info;
 178         struct irdp_interface *irdp = &zi->irdp;
 179         char buf[PREFIX_STRLEN];
 180         u_int32_t dst;
 181         u_int32_t ttl = 1;
 182
 183         if (!(ifp->flags & IFF_UP))
 184                 return;
 185
 186         if (irdp->flags & IF_BROADCAST)
 187                 dst = INADDR_BROADCAST;
 188         else
 189                 dst = htonl(INADDR_ALLHOSTS_GROUP);
 190
 191         if (irdp->flags & IF_DEBUG_MESSAGES)
 192                 zlog_debug("IRDP: TX Advert on %s %s Holdtime=%d Preference=%d",
 193                            ifp->name, prefix2str(p, buf, sizeof buf),
 194                            irdp->flags & IF_SHUTDOWN ? 0 : irdp->Lifetime,
 195                            get_pref(irdp, p));
 196
 197         send_packet(ifp, s, dst, p, ttl);
 198 }
 199
 200 static void irdp_advertisement(struct interface *ifp, struct prefix *p)
 201 {
 202         struct stream *s;
 203         s = stream_new(128);
 204         make_advertisement_packet(ifp, p, s);
 205         irdp_send(ifp, p, s);
 206         stream_free(s);
 207 }
 208
 209 int irdp_send_thread(struct thread *t_advert)
 210 {
 211         u_int32_t timer, tmp;
 212         struct interface *ifp = THREAD_ARG(t_advert);
 213         struct zebra_if *zi = ifp->info;
 214         struct irdp_interface *irdp = &zi->irdp;
 215         struct prefix *p;
 216         struct listnode *node, *nnode;
 217         struct connected *ifc;
 218
 219         irdp->flags &= ~IF_SOLICIT;
 220
 221         if (ifp->connected)
 222                 for (ALL_LIST_ELEMENTS(ifp->connected, node, nnode, ifc)) {
 223                         p = ifc->address;
 224
 225                         if (p->family != AF_INET)
 226                                 continue;
 227
 228                         irdp_advertisement(ifp, p);
 229                         irdp->irdp_sent++;
 230                 }
 231
 232         tmp = irdp->MaxAdvertInterval - irdp->MinAdvertInterval;
 233         timer = random() % (tmp + 1);
 234         timer = irdp->MinAdvertInterval + timer;
 235
 236         if (irdp->irdp_sent < MAX_INITIAL_ADVERTISEMENTS
 237             && timer > MAX_INITIAL_ADVERT_INTERVAL)
 238                 timer = MAX_INITIAL_ADVERT_INTERVAL;
 239
 240         if (irdp->flags & IF_DEBUG_MISC)
 241                 zlog_debug("IRDP: New timer for %s set to %u\n", ifp->name,
 242                            timer);
 243
 244         irdp->t_advertise = NULL;
 245         thread_add_timer(zebrad.master, irdp_send_thread, ifp, timer,
 246                          &irdp->t_advertise);
 247         return 0;
 248 }
 249
 250 void irdp_advert_off(struct interface *ifp)
 251 {
 252         struct zebra_if *zi = ifp->info;
 253         struct irdp_interface *irdp = &zi->irdp;
 254         struct listnode *node, *nnode;
 255         int i;
 256         struct connected *ifc;
 257         struct prefix *p;
 258
 259         if (irdp->t_advertise)
 260                 thread_cancel(irdp->t_advertise);
 261         irdp->t_advertise = NULL;
 262
 263         if (ifp->connected)
 264                 for (ALL_LIST_ELEMENTS(ifp->connected, node, nnode, ifc)) {
 265                         p = ifc->address;
 266
 267                         /* Output some packets with Lifetime 0
 268                            we should add a wait...
 269                         */
 270
 271                         for (i = 0; i < IRDP_LAST_ADVERT_MESSAGES; i++) {
 272                                 irdp->irdp_sent++;
 273                                 irdp_advertisement(ifp, p);
 274                         }
 275                 }
 276 }
 277
 278
 279 void process_solicit(struct interface *ifp)
 280 {
 281         struct zebra_if *zi = ifp->info;
 282         struct irdp_interface *irdp = &zi->irdp;
 283         u_int32_t timer;
 284
 285         /* When SOLICIT is active we reject further incoming solicits
 286            this keeps down the answering rate so we don't have think
 287            about DoS attacks here. */
 288
 289         if (irdp->flags & IF_SOLICIT)
 290                 return;
 291
 292         irdp->flags |= IF_SOLICIT;
 293         if (irdp->t_advertise)
 294                 thread_cancel(irdp->t_advertise);
 295         irdp->t_advertise = NULL;
 296
 297         timer = (random() % MAX_RESPONSE_DELAY) + 1;
 298
 299         irdp->t_advertise = NULL;
 300         thread_add_timer(zebrad.master, irdp_send_thread, ifp, timer,
 301                          &irdp->t_advertise);
 302 }
 303
 304 void irdp_finish()
 305 {
 306         struct vrf *vrf;
 307         struct listnode *node, *nnode;
 308         struct interface *ifp;
 309         struct zebra_if *zi;
 310         struct irdp_interface *irdp;
 311
 312         zlog_info("IRDP: Received shutdown notification.");
 313
 314         RB_FOREACH(vrf, vrf_id_head, &vrfs_by_id)
 315         for (ALL_LIST_ELEMENTS(vrf->iflist, node, nnode, ifp)) {
 316                 zi = ifp->info;
 317
 318                 if (!zi)
 319                         continue;
 320                 irdp = &zi->irdp;
 321                 if (!irdp)
 322                         continue;
 323
 324                 if (irdp->flags & IF_ACTIVE) {
 325                         irdp->flags |= IF_SHUTDOWN;
 326                         irdp_advert_off(ifp);
 327                 }
 328         }
 329 }
 330
 331 #endif /* HAVE_IRDP */