diff options
Diffstat (limited to 'zebra/zebra_rib.c')
| -rw-r--r-- | zebra/zebra_rib.c | 240 |
1 files changed, 235 insertions, 5 deletions
diff --git a/zebra/zebra_rib.c b/zebra/zebra_rib.c index 7a63c1c1..f61cbe31 100644 --- a/zebra/zebra_rib.c +++ b/zebra/zebra_rib.c @@ -631,6 +631,82 @@ rib_lookup_ipv4 (struct prefix_ipv4 *p) return NULL; } +/* + * This clone function, unlike its original rib_lookup_ipv4(), checks + * if specified IPv4 route record (prefix/mask -> gate) exists in + * the whole RIB and has ZEBRA_FLAG_SELECTED set. + * + * Return values: + * -1: error + * 0: exact match found + * 1: a match was found with a different gate + * 2: connected route found + * 3: no matches found + */ +int +rib_lookup_ipv4_route (struct prefix_ipv4 *p, union sockunion * qgate) +{ + struct route_table *table; + struct route_node *rn; + struct rib *match; + struct nexthop *nexthop; + + /* Lookup table. */ + table = vrf_table (AFI_IP, SAFI_UNICAST, 0); + if (! table) + return ZEBRA_RIB_LOOKUP_ERROR; + + /* Scan the RIB table for exactly matching RIB entry. */ + rn = route_node_lookup (table, (struct prefix *) p); + + /* No route for this prefix. */ + if (! rn) + return ZEBRA_RIB_NOTFOUND; + + /* Unlock node. */ + route_unlock_node (rn); + + /* Find out if a "selected" RR for the discovered RIB entry exists ever. */ + for (match = rn->info; match; match = match->next) + { + if (CHECK_FLAG (match->status, RIB_ENTRY_REMOVED)) + continue; + if (CHECK_FLAG (match->flags, ZEBRA_FLAG_SELECTED)) + break; + } + + /* None such found :( */ + if (!match) + return ZEBRA_RIB_NOTFOUND; + + if (match->type == ZEBRA_ROUTE_CONNECT) + return ZEBRA_RIB_FOUND_CONNECTED; + + /* Ok, we have a cood candidate, let's check it's nexthop list... */ + for (nexthop = match->nexthop; nexthop; nexthop = nexthop->next) + if (CHECK_FLAG (nexthop->flags, NEXTHOP_FLAG_FIB)) + { + /* We are happy with either direct or recursive hexthop */ + if (nexthop->gate.ipv4.s_addr == qgate->sin.sin_addr.s_addr || + nexthop->rgate.ipv4.s_addr == qgate->sin.sin_addr.s_addr) + return ZEBRA_RIB_FOUND_EXACT; + else + { + if (IS_ZEBRA_DEBUG_RIB) + { + char gate_buf[INET_ADDRSTRLEN], rgate_buf[INET_ADDRSTRLEN], qgate_buf[INET_ADDRSTRLEN]; + inet_ntop (AF_INET, &nexthop->gate.ipv4.s_addr, gate_buf, INET_ADDRSTRLEN); + inet_ntop (AF_INET, &nexthop->rgate.ipv4.s_addr, rgate_buf, INET_ADDRSTRLEN); + inet_ntop (AF_INET, &qgate->sin.sin_addr.s_addr, qgate_buf, INET_ADDRSTRLEN); + zlog_debug ("%s: qgate == %s, gate == %s, rgate == %s", __func__, qgate_buf, gate_buf, rgate_buf); + } + return ZEBRA_RIB_FOUND_NOGATE; + } + } + + return ZEBRA_RIB_NOTFOUND; +} + #ifdef HAVE_IPV6 struct rib * rib_match_ipv6 (struct in6_addr *addr) @@ -694,6 +770,16 @@ rib_match_ipv6 (struct in6_addr *addr) #define RIB_SYSTEM_ROUTE(R) \ ((R)->type == ZEBRA_ROUTE_KERNEL || (R)->type == ZEBRA_ROUTE_CONNECT) +/* This function verifies reachability of one given nexthop, which can be + * numbered or unnumbered, IPv4 or IPv6. The result is unconditionally stored + * in nexthop->flags field. If the 4th parameter, 'set', is non-zero, + * nexthop->ifindex will be updated appropriately as well. + * An existing route map can turn (otherwise active) nexthop into inactive, but + * not vice versa. + * + * The return value is the final value of 'ACTIVE' flag. + */ + static int nexthop_active_check (struct route_node *rn, struct rib *rib, struct nexthop *nexthop, int set) @@ -839,6 +925,7 @@ rib_install_kernel (struct route_node *rn, struct rib *rib) #endif /* HAVE_IPV6 */ } + /* This condition is never met, if we are using rt_socket.c */ if (ret < 0) { for (nexthop = rib->nexthop; nexthop; nexthop = nexthop->next) @@ -860,6 +947,8 @@ rib_uninstall_kernel (struct route_node *rn, struct rib *rib) break; #ifdef HAVE_IPV6 case AF_INET6: + if (IS_ZEBRA_DEBUG_RIB) + zlog_debug ("%s: calling kernel_delete_ipv4 (%p, %p)", __func__, rn, rib); ret = kernel_delete_ipv6 (&rn->p, rib); break; #endif /* HAVE_IPV6 */ @@ -907,6 +996,9 @@ rib_process (struct work_queue *wq, void *data) for (rib = rn->info; rib; rib = next) { + /* The next pointer is saved, because current pointer + * may be passed to rib_unlink() in the middle of iteration. + */ next = rib->next; /* Currently installed rib. */ @@ -983,9 +1075,16 @@ rib_process (struct work_queue *wq, void *data) /* metric tie-breaks equal distance */ if (rib->metric <= select->metric) select = rib; - } - - /* Same route is selected. */ + } /* for (rib = rn->info; rib; rib = next) */ + + /* After the cycle is finished, the following pointers will be set: + * select --- the winner RIB entry, if any was found, otherwise NULL + * fib --- the SELECTED RIB entry, if any, otherwise NULL + * del --- equal to fib, if fib is queued for deletion, NULL otherwise + * rib --- NULL + */ + + /* Same RIB entry is selected. Update FIB and finish. */ if (select && select == fib) { if (IS_ZEBRA_DEBUG_RIB) @@ -1024,7 +1123,10 @@ rib_process (struct work_queue *wq, void *data) goto end; } - /* Uninstall old rib from forwarding table. */ + /* At this point we either haven't found the best RIB entry or it is + * different from what we currently intend to flag with SELECTED. In both + * cases, if a RIB block is present in FIB, it should be withdrawn. + */ if (fib) { if (IS_ZEBRA_DEBUG_RIB) @@ -1039,7 +1141,10 @@ rib_process (struct work_queue *wq, void *data) nexthop_active_update (rn, fib, 1); } - /* Install new rib into forwarding table. */ + /* Regardless of some RIB entry being SELECTED or not before, now we can + * tell, that if a new winner exists, FIB is still not updated with this + * data, but ready to be. + */ if (select) { if (IS_ZEBRA_DEBUG_RIB) @@ -1382,16 +1487,127 @@ rib_add_ipv4 (int type, int flags, struct prefix_ipv4 *p, SET_FLAG (nexthop->flags, NEXTHOP_FLAG_FIB); /* Link new rib to node.*/ + if (IS_ZEBRA_DEBUG_RIB) + zlog_debug ("%s: calling rib_addnode (%p, %p)", __func__, rn, rib); rib_addnode (rn, rib); /* Free implicit route.*/ if (same) + { + if (IS_ZEBRA_DEBUG_RIB) + zlog_debug ("%s: calling rib_delnode (%p, %p)", __func__, rn, rib); rib_delnode (rn, same); + } route_unlock_node (rn); return 0; } +/* This function dumps the contents of a given RIB entry into + * standard debug log. Calling function name and IP prefix in + * question are passed as 1st and 2nd arguments. + */ + +void rib_dump (const char * func, const struct prefix_ipv4 * p, const struct rib * rib) +{ + char straddr1[INET_ADDRSTRLEN], straddr2[INET_ADDRSTRLEN]; + struct nexthop *nexthop; + + inet_ntop (AF_INET, &p->prefix, straddr1, INET_ADDRSTRLEN); + zlog_debug ("%s: dumping RIB entry %p for %s/%d", func, rib, straddr1, p->prefixlen); + zlog_debug + ( + "%s: refcnt == %lu, uptime == %u, type == %u, table == %d", + func, + rib->refcnt, + rib->uptime, + rib->type, + rib->table + ); + zlog_debug + ( + "%s: metric == %u, distance == %u, flags == %u, status == %u", + func, + rib->metric, + rib->distance, + rib->flags, + rib->status + ); + zlog_debug + ( + "%s: nexthop_num == %u, nexthop_active_num == %u, nexthop_fib_num == %u", + func, + rib->nexthop_num, + rib->nexthop_active_num, + rib->nexthop_fib_num + ); + for (nexthop = rib->nexthop; nexthop; nexthop = nexthop->next) + { + inet_ntop (AF_INET, &nexthop->gate.ipv4.s_addr, straddr1, INET_ADDRSTRLEN); + inet_ntop (AF_INET, &nexthop->rgate.ipv4.s_addr, straddr2, INET_ADDRSTRLEN); + zlog_debug + ( + "%s: NH %s (%s) with flags %s%s%s", + func, + straddr1, + straddr2, + (CHECK_FLAG (nexthop->flags, NEXTHOP_FLAG_ACTIVE) ? "ACTIVE " : ""), + (CHECK_FLAG (nexthop->flags, NEXTHOP_FLAG_FIB) ? "FIB " : ""), + (CHECK_FLAG (nexthop->flags, NEXTHOP_FLAG_RECURSIVE) ? "RECURSIVE" : "") + ); + } + zlog_debug ("%s: dump complete", func); +} + +/* This is an exported helper to rtm_read() to dump the strange + * RIB entry found by rib_lookup_ipv4_route() + */ + +void rib_lookup_and_dump (struct prefix_ipv4 * p) +{ + struct route_table *table; + struct route_node *rn; + struct rib *rib; + char prefix_buf[INET_ADDRSTRLEN]; + + /* Lookup table. */ + table = vrf_table (AFI_IP, SAFI_UNICAST, 0); + if (! table) + { + zlog_err ("%s: vrf_table() returned NULL", __func__); + return; + } + + inet_ntop (AF_INET, &p->prefix.s_addr, prefix_buf, INET_ADDRSTRLEN); + /* Scan the RIB table for exactly matching RIB entry. */ + rn = route_node_lookup (table, (struct prefix *) p); + + /* No route for this prefix. */ + if (! rn) + { + zlog_debug ("%s: lookup failed for %s/%d", __func__, prefix_buf, p->prefixlen); + return; + } + + /* Unlock node. */ + route_unlock_node (rn); + + /* let's go */ + for (rib = rn->info; rib; rib = rib->next) + { + zlog_debug + ( + "%s: rn %p, rib %p: %s, %s", + __func__, + rn, + rib, + (CHECK_FLAG (rib->status, RIB_ENTRY_REMOVED) ? "removed" : "NOT removed"), + (CHECK_FLAG (rib->flags, ZEBRA_FLAG_SELECTED) ? "selected" : "NOT selected") + ); + rib_dump (__func__, p, rib); + } +} + int rib_add_ipv4_multipath (struct prefix_ipv4 *p, struct rib *rib) { @@ -1440,10 +1656,24 @@ rib_add_ipv4_multipath (struct prefix_ipv4 *p, struct rib *rib) /* Link new rib to node.*/ rib_addnode (rn, rib); + if (IS_ZEBRA_DEBUG_RIB) + { + zlog_debug ("%s: called rib_addnode (%p, %p) on new RIB entry", + __func__, rn, rib); + rib_dump (__func__, p, rib); + } /* Free implicit route.*/ if (same) + { + if (IS_ZEBRA_DEBUG_RIB) + { + zlog_debug ("%s: calling rib_delnode (%p, %p) on existing RIB entry", + __func__, rn, same); + rib_dump (__func__, p, same); + } rib_delnode (rn, same); + } route_unlock_node (rn); return 0; |