eigrpd/eigrp_network.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * EIGRP Network Related Functions.
   4  * Copyright (C) 2013-2014
   5  * Authors:
   6  *   Donnie Savage
   7  *   Jan Janovic
   8  *   Matej Perina
   9  *   Peter Orsag
  10  *   Peter Paluch
  11  */
  12
  13 #include <zebra.h>
  14
  15 #include "thread.h"
  16 #include "linklist.h"
  17 #include "prefix.h"
  18 #include "if.h"
  19 #include "sockunion.h"
  20 #include "log.h"
  21 #include "sockopt.h"
  22 #include "privs.h"
  23 #include "table.h"
  24 #include "vty.h"
  25 #include "lib_errors.h"
  26
  27 #include "eigrpd/eigrp_structs.h"
  28 #include "eigrpd/eigrpd.h"
  29 #include "eigrpd/eigrp_interface.h"
  30 #include "eigrpd/eigrp_neighbor.h"
  31 #include "eigrpd/eigrp_packet.h"
  32 #include "eigrpd/eigrp_zebra.h"
  33 #include "eigrpd/eigrp_vty.h"
  34 #include "eigrpd/eigrp_network.h"
  35
  36 static int eigrp_network_match_iface(const struct prefix *connected_prefix,
  37                                      const struct prefix *prefix);
  38 static void eigrp_network_run_interface(struct eigrp *, struct prefix *,
  39                                         struct interface *);
  40
  41 int eigrp_sock_init(struct vrf *vrf)
  42 {
  43         int eigrp_sock = -1;
  44         int ret;
  45 #ifdef IP_HDRINCL
  46         int hincl = 1;
  47 #endif
  48
  49         if (!vrf)
  50                 return eigrp_sock;
  51
  52         frr_with_privs(&eigrpd_privs) {
  53                 eigrp_sock = vrf_socket(
  54                         AF_INET, SOCK_RAW, IPPROTO_EIGRPIGP, vrf->vrf_id,
  55                         vrf->vrf_id != VRF_DEFAULT ? vrf->name : NULL);
  56                 if (eigrp_sock < 0) {
  57                         zlog_err("%s: socket: %s",
  58                                  __func__, safe_strerror(errno));
  59                         exit(1);
  60                 }
  61
  62 #ifdef IP_HDRINCL
  63                 /* we will include IP header with packet */
  64                 ret = setsockopt(eigrp_sock, IPPROTO_IP, IP_HDRINCL, &hincl,
  65                                  sizeof(hincl));
  66                 if (ret < 0) {
  67                         zlog_warn("Can't set IP_HDRINCL option for fd %d: %s",
  68                                   eigrp_sock, safe_strerror(errno));
  69                 }
  70 #elif defined(IPTOS_PREC_INTERNETCONTROL)
  71 #warning "IP_HDRINCL not available on this system"
  72 #warning "using IPTOS_PREC_INTERNETCONTROL"
  73                 ret = setsockopt_ipv4_tos(eigrp_sock,
  74                                           IPTOS_PREC_INTERNETCONTROL);
  75                 if (ret < 0) {
  76                         zlog_warn("can't set sockopt IP_TOS %d to socket %d: %s",
  77                                   tos, eigrp_sock, safe_strerror(errno));
  78                         close(eigrp_sock); /* Prevent sd leak. */
  79                         return ret;
  80                 }
  81 #else /* !IPTOS_PREC_INTERNETCONTROL */
  82 #warning "IP_HDRINCL not available, nor is IPTOS_PREC_INTERNETCONTROL"
  83                 zlog_warn("IP_HDRINCL option not available");
  84 #endif /* IP_HDRINCL */
  85
  86                 ret = setsockopt_ifindex(AF_INET, eigrp_sock, 1);
  87                 if (ret < 0)
  88                         zlog_warn("Can't set pktinfo option for fd %d",
  89                                   eigrp_sock);
  90         }
  91
  92         return eigrp_sock;
  93 }
  94
  95 void eigrp_adjust_sndbuflen(struct eigrp *eigrp, unsigned int buflen)
  96 {
  97         int newbuflen;
  98         /* Check if any work has to be done at all. */
  99         if (eigrp->maxsndbuflen >= buflen)
 100                 return;
 101
 102         /* Now we try to set SO_SNDBUF to what our caller has requested
 103          * (the MTU of a newly added interface). However, if the OS has
 104          * truncated the actual buffer size to somewhat less size, try
 105          * to detect it and update our records appropriately. The OS
 106          * may allocate more buffer space, than requested, this isn't
 107          * a error.
 108          */
 109         setsockopt_so_sendbuf(eigrp->fd, buflen);
 110         newbuflen = getsockopt_so_sendbuf(eigrp->fd);
 111         if (newbuflen < 0 || newbuflen < (int)buflen)
 112                 zlog_warn("%s: tried to set SO_SNDBUF to %u, but got %d",
 113                           __func__, buflen, newbuflen);
 114         if (newbuflen >= 0)
 115                 eigrp->maxsndbuflen = (unsigned int)newbuflen;
 116         else
 117                 zlog_warn("%s: failed to get SO_SNDBUF", __func__);
 118 }
 119
 120 int eigrp_if_ipmulticast(struct eigrp *top, struct prefix *p,
 121                          unsigned int ifindex)
 122 {
 123         uint8_t val;
 124         int ret, len;
 125
 126         val = 0;
 127         len = sizeof(val);
 128
 129         /* Prevent receiving self-origined multicast packets. */
 130         ret = setsockopt(top->fd, IPPROTO_IP, IP_MULTICAST_LOOP, (void *)&val,
 131                          len);
 132         if (ret < 0)
 133                 zlog_warn(
 134                         "can't setsockopt IP_MULTICAST_LOOP (0) for fd %d: %s",
 135                         top->fd, safe_strerror(errno));
 136
 137         /* Explicitly set multicast ttl to 1 -- endo. */
 138         val = 1;
 139         ret = setsockopt(top->fd, IPPROTO_IP, IP_MULTICAST_TTL, (void *)&val,
 140                          len);
 141         if (ret < 0)
 142                 zlog_warn("can't setsockopt IP_MULTICAST_TTL (1) for fd %d: %s",
 143                           top->fd, safe_strerror(errno));
 144
 145         ret = setsockopt_ipv4_multicast_if(top->fd, p->u.prefix4, ifindex);
 146         if (ret < 0)
 147                 zlog_warn(
 148                         "can't setsockopt IP_MULTICAST_IF (fd %d, addr %pI4, ifindex %u): %s",
 149                         top->fd, &p->u.prefix4, ifindex, safe_strerror(errno));
 150
 151         return ret;
 152 }
 153
 154 /* Join to the EIGRP multicast group. */
 155 int eigrp_if_add_allspfrouters(struct eigrp *top, struct prefix *p,
 156                                unsigned int ifindex)
 157 {
 158         int ret;
 159
 160         ret = setsockopt_ipv4_multicast(
 161                 top->fd, IP_ADD_MEMBERSHIP, p->u.prefix4,
 162                 htonl(EIGRP_MULTICAST_ADDRESS), ifindex);
 163         if (ret < 0)
 164                 zlog_warn(
 165                         "can't setsockopt IP_ADD_MEMBERSHIP (fd %d, addr %pI4, ifindex %u, AllSPFRouters): %s; perhaps a kernel limit on # of multicast group memberships has been exceeded?",
 166                         top->fd, &p->u.prefix4, ifindex, safe_strerror(errno));
 167         else
 168                 zlog_debug("interface %pI4 [%u] join EIGRP Multicast group.",
 169                            &p->u.prefix4, ifindex);
 170
 171         return ret;
 172 }
 173
 174 int eigrp_if_drop_allspfrouters(struct eigrp *top, struct prefix *p,
 175                                 unsigned int ifindex)
 176 {
 177         int ret;
 178
 179         ret = setsockopt_ipv4_multicast(
 180                 top->fd, IP_DROP_MEMBERSHIP, p->u.prefix4,
 181                 htonl(EIGRP_MULTICAST_ADDRESS), ifindex);
 182         if (ret < 0)
 183                 zlog_warn(
 184                         "can't setsockopt IP_DROP_MEMBERSHIP (fd %d, addr %pI4, ifindex %u, AllSPFRouters): %s",
 185                         top->fd, &p->u.prefix4, ifindex, safe_strerror(errno));
 186         else
 187                 zlog_debug("interface %pI4 [%u] leave EIGRP Multicast group.",
 188                            &p->u.prefix4, ifindex);
 189
 190         return ret;
 191 }
 192
 193 int eigrp_network_set(struct eigrp *eigrp, struct prefix *p)
 194 {
 195         struct vrf *vrf = vrf_lookup_by_id(eigrp->vrf_id);
 196         struct route_node *rn;
 197         struct interface *ifp;
 198
 199         rn = route_node_get(eigrp->networks, p);
 200         if (rn->info) {
 201                 /* There is already same network statement. */
 202                 route_unlock_node(rn);
 203                 return 0;
 204         }
 205
 206         struct prefix *pref = prefix_new();
 207         prefix_copy(pref, p);
 208         rn->info = (void *)pref;
 209
 210         /* Schedule Router ID Update. */
 211         if (eigrp->router_id.s_addr == INADDR_ANY)
 212                 eigrp_router_id_update(eigrp);
 213         /* Run network config now. */
 214         /* Get target interface. */
 215         FOR_ALL_INTERFACES (vrf, ifp) {
 216                 zlog_debug("Setting up %s", ifp->name);
 217                 eigrp_network_run_interface(eigrp, p, ifp);
 218         }
 219         return 1;
 220 }
 221
 222 /* Check whether interface matches given network
 223  * returns: 1, true. 0, false
 224  */
 225 static int eigrp_network_match_iface(const struct prefix *co_prefix,
 226                                      const struct prefix *net)
 227 {
 228         /* new approach: more elegant and conceptually clean */
 229         return prefix_match_network_statement(net, co_prefix);
 230 }
 231
 232 static void eigrp_network_run_interface(struct eigrp *eigrp, struct prefix *p,
 233                                         struct interface *ifp)
 234 {
 235         struct eigrp_interface *ei;
 236         struct listnode *cnode;
 237         struct connected *co;
 238
 239         /* if interface prefix is match specified prefix,
 240            then create socket and join multicast group. */
 241         for (ALL_LIST_ELEMENTS_RO(ifp->connected, cnode, co)) {
 242
 243                 if (CHECK_FLAG(co->flags, ZEBRA_IFA_SECONDARY))
 244                         continue;
 245
 246                 if (p->family == co->address->family && !ifp->info
 247                     && eigrp_network_match_iface(co->address, p)) {
 248
 249                         ei = eigrp_if_new(eigrp, ifp, co->address);
 250
 251                         /* Relate eigrp interface to eigrp instance. */
 252                         ei->eigrp = eigrp;
 253
 254                         /* if router_id is not configured, dont bring up
 255                          * interfaces.
 256                          * eigrp_router_id_update() will call eigrp_if_update
 257                          * whenever r-id is configured instead.
 258                          */
 259                         if (if_is_operative(ifp))
 260                                 eigrp_if_up(ei);
 261                 }
 262         }
 263 }
 264
 265 void eigrp_if_update(struct interface *ifp)
 266 {
 267         struct listnode *node, *nnode;
 268         struct route_node *rn;
 269         struct eigrp *eigrp;
 270
 271         /*
 272          * In the event there are multiple eigrp autonymnous systems running,
 273          * we need to check eac one and add the interface as approperate
 274          */
 275         for (ALL_LIST_ELEMENTS(eigrp_om->eigrp, node, nnode, eigrp)) {
 276                 if (ifp->vrf->vrf_id != eigrp->vrf_id)
 277                         continue;
 278
 279                 /* EIGRP must be on and Router-ID must be configured. */
 280                 if (eigrp->router_id.s_addr == INADDR_ANY)
 281                         continue;
 282
 283                 /* Run each network for this interface. */
 284                 for (rn = route_top(eigrp->networks); rn; rn = route_next(rn))
 285                         if (rn->info != NULL) {
 286                                 eigrp_network_run_interface(eigrp, &rn->p, ifp);
 287                         }
 288         }
 289 }
 290
 291 int eigrp_network_unset(struct eigrp *eigrp, struct prefix *p)
 292 {
 293         struct route_node *rn;
 294         struct listnode *node, *nnode;
 295         struct eigrp_interface *ei;
 296         struct prefix *pref;
 297
 298         rn = route_node_lookup(eigrp->networks, p);
 299         if (rn == NULL)
 300                 return 0;
 301
 302         pref = rn->info;
 303         route_unlock_node(rn);
 304
 305         if (!IPV4_ADDR_SAME(&pref->u.prefix4, &p->u.prefix4))
 306                 return 0;
 307
 308         prefix_ipv4_free((struct prefix_ipv4 **)&rn->info);
 309         route_unlock_node(rn); /* initial reference */
 310
 311         /* Find interfaces that not configured already.  */
 312         for (ALL_LIST_ELEMENTS(eigrp->eiflist, node, nnode, ei)) {
 313                 bool found = false;
 314
 315                 for (rn = route_top(eigrp->networks); rn; rn = route_next(rn)) {
 316                         if (rn->info == NULL)
 317                                 continue;
 318
 319                         if (eigrp_network_match_iface(&ei->address, &rn->p)) {
 320                                 found = true;
 321                                 route_unlock_node(rn);
 322                                 break;
 323                         }
 324                 }
 325
 326                 if (!found) {
 327                         eigrp_if_free(ei, INTERFACE_DOWN_BY_VTY);
 328                 }
 329         }
 330
 331         return 1;
 332 }
 333
 334 void eigrp_external_routes_refresh(struct eigrp *eigrp, int type)
 335 {
 336 }