isisd: fix setting of the attached bit

Current code related to setting of the attached bit checks for existence
of L2 adjacencies in other routers configured on the device. This makes
no sense. We should check for L2 adjacencies in the same router where we
have L1 adjacencies.

Signed-off-by: Igor Ryzhov <iryzhov@nfware.com>
(cherry picked from commit 74ef8dd96158b3e0898a323d893f74449e0a412a)

diff --git a/isisd/isis_lsp.c b/isisd/isis_lsp.c
index 814ba8fc2a130c4cd802f4e2bdff4da309989d8f..87a6061d4e234f804180ef2a8ebc19402d8521b1 100644 (file)
--- a/isisd/isis_lsp.c
+++ b/isisd/isis_lsp.c
@@ -401,93 +401,74 @@ static void lsp_seqno_update(struct isis_lsp *lsp0)
        return;
 }
 
-static bool isis_level2_adj_up(struct isis_area *curr_area)
+static bool isis_level2_adj_up(struct isis_area *area)
 {
        struct listnode *node, *cnode;
        struct isis_circuit *circuit;
        struct list *adjdb;
        struct isis_adjacency *adj;
-       struct isis *isis = curr_area->isis;
-       struct isis_area *area;
-
-       /* lookup for a Level2 adjacency up in another area */
-       for (ALL_LIST_ELEMENTS_RO(isis->area_list, node, area)) {
-               if (area->area_tag
-                   && strcmp(area->area_tag, curr_area->area_tag) == 0)
-                       continue;
 
-               for (ALL_LIST_ELEMENTS_RO(area->circuit_list, cnode, circuit)) {
-                       if (circuit->circ_type == CIRCUIT_T_BROADCAST) {
-                               adjdb = circuit->u.bc.adjdb[1];
-                               if (!adjdb || !adjdb->count)
-                                       continue;
+       for (ALL_LIST_ELEMENTS_RO(area->circuit_list, cnode, circuit)) {
+               if (circuit->circ_type == CIRCUIT_T_BROADCAST) {
+                       adjdb = circuit->u.bc.adjdb[1];
+                       if (!adjdb || !adjdb->count)
+                               continue;
 
-                               for (ALL_LIST_ELEMENTS_RO(adjdb, node, adj)) {
-                                       if (adj->level != ISIS_ADJ_LEVEL1
-                                           && adj->adj_state == ISIS_ADJ_UP)
-                                               return true;
-                               }
-                       } else if (circuit->circ_type == CIRCUIT_T_P2P
-                                  && circuit->u.p2p.neighbor) {
-                               adj = circuit->u.p2p.neighbor;
+                       for (ALL_LIST_ELEMENTS_RO(adjdb, node, adj)) {
                                if (adj->level != ISIS_ADJ_LEVEL1
                                    && adj->adj_state == ISIS_ADJ_UP)
                                        return true;
                        }
+               } else if (circuit->circ_type == CIRCUIT_T_P2P
+                          && circuit->u.p2p.neighbor) {
+                       adj = circuit->u.p2p.neighbor;
+                       if (adj->level != ISIS_ADJ_LEVEL1
+                           && adj->adj_state == ISIS_ADJ_UP)
+                               return true;
                }
        }
+
        return false;
 }
 
-static void isis_reset_attach_bit(struct isis_adjacency *curr_adj)
+static void isis_reset_attach_bit(struct isis_adjacency *adj)
 {
-       struct listnode *node;
-       struct isis_area *curr_area = curr_adj->circuit->area;
-       struct isis *isis = curr_area->isis;
-       struct isis_area *area;
+       struct isis_area *area = adj->circuit->area;
        struct lspdb_head *head;
        struct isis_lsp *lsp;
        uint8_t lspid[ISIS_SYS_ID_LEN + 2];
 
-       /* If new adjaceny is up and area is level2 or level1and2 verify if
-        * we have LSPs in other areas that should now set the attach bit.
-        *
-        * If adjacenty is down, verify if we no longer have another level2
-        * or level1and2 areas so that we should now remove the attach bit.
+       /*
+        * If an L2 adjacency changed its state in L-1-2 area, we have to:
+        * - set the attached bit in L1 LSPs if it's the first L2 adjacency
+        * - remove the attached bit in L1 LSPs if it's the last L2 adjacency
         */
-       if (curr_area->is_type == IS_LEVEL_1)
-               return;
 
-       for (ALL_LIST_ELEMENTS_RO(isis->area_list, node, area)) {
-               if (area->area_tag
-                   && strcmp(area->area_tag, curr_area->area_tag) == 0)
-                       continue;
+       if (area->is_type != IS_LEVEL_1_AND_2 || adj->level == ISIS_ADJ_LEVEL1)
+               return;
 
-               if (!area->attached_bit_send)
-                       continue;
+       if (!area->attached_bit_send)
+               return;
 
-               head = &area->lspdb[IS_LEVEL_1 - 1];
-               memset(lspid, 0, ISIS_SYS_ID_LEN + 2);
-               memcpy(lspid, area->isis->sysid, ISIS_SYS_ID_LEN);
+       head = &area->lspdb[IS_LEVEL_1 - 1];
+       memset(lspid, 0, ISIS_SYS_ID_LEN + 2);
+       memcpy(lspid, area->isis->sysid, ISIS_SYS_ID_LEN);
 
-               lsp = lsp_search(head, lspid);
-               if (!lsp)
-                       continue;
+       lsp = lsp_search(head, lspid);
+       if (!lsp)
+               return;
 
-               if (curr_adj->adj_state == ISIS_ADJ_UP
-                   && !(lsp->hdr.lsp_bits & LSPBIT_ATT)) {
-                       sched_debug(
-                               "ISIS (%s): adj going up regenerate lsp-bits",
-                               area->area_tag);
-                       lsp_regenerate_schedule(area, IS_LEVEL_1, 0);
-               } else if (curr_adj->adj_state == ISIS_ADJ_DOWN
-                          && lsp->hdr.lsp_bits & LSPBIT_ATT
-                          && !isis_level2_adj_up(area)) {
-                       sched_debug(
-                               "ISIS (%s): adj going down regenerate lsp-bits",
-                               area->area_tag);
-                       lsp_regenerate_schedule(area, IS_LEVEL_1, 0);
-               }
+       if (adj->adj_state == ISIS_ADJ_UP
+           && !(lsp->hdr.lsp_bits & LSPBIT_ATT)) {
+               sched_debug("ISIS (%s): adj going up regenerate lsp-bits",
+                           area->area_tag);
+               lsp_regenerate_schedule(area, IS_LEVEL_1, 0);
+       } else if (adj->adj_state == ISIS_ADJ_DOWN
+                  && (lsp->hdr.lsp_bits & LSPBIT_ATT)
+                  && !isis_level2_adj_up(area)) {
+               sched_debug("ISIS (%s): adj going down regenerate lsp-bits",
+                           area->area_tag);
+               lsp_regenerate_schedule(area, IS_LEVEL_1, 0);
        }
 }