From be8e0d318815395a49632f8c6546be1f96c17557 Mon Sep 17 00:00:00 2001 From: Renato Westphal Date: Fri, 3 Mar 2017 17:50:22 -0300 Subject: [PATCH] ldpd: fix processing of Label Withdraw messages Whenever we receive a Label Withdraw message with an optional Label TLV, we should check if this label matches the label previously received from this neighbor for this FEC. If they don't match then we shouldn't uninstall the previous label from the kernel. This fixes a misinterpretation from the "Receive Label Withdraw" algorithm described in the A.1.5 section of RFC 5036. Also, simplify the check of pending withdraws in lde_check_release() and lde_check_release_wcard(). Signed-off-by: Renato Westphal --- ldpd/lde_lib.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/ldpd/lde_lib.c b/ldpd/lde_lib.c index 6ec88a19bd..02730189a8 100644 --- a/ldpd/lde_lib.c +++ b/ldpd/lde_lib.c @@ -624,8 +624,7 @@ lde_check_release(struct map *map, struct lde_nbr *ln) /* LRl.3: first check if we have a pending withdraw running */ lw = (struct lde_wdraw *)fec_find(&ln->sent_wdraw, &fn->fec); - if (lw && (map->label == NO_LABEL || - (lw->label != NO_LABEL && map->label == lw->label))) { + if (lw && (map->label == NO_LABEL || map->label == lw->label)) { /* LRl.4: delete record of outstanding label withdraw */ lde_wdraw_del(ln, lw); } @@ -654,8 +653,7 @@ lde_check_release_wcard(struct map *map, struct lde_nbr *ln) /* LRl.3: first check if we have a pending withdraw running */ lw = (struct lde_wdraw *)fec_find(&ln->sent_wdraw, &fn->fec); - if (lw && (map->label == NO_LABEL || - (lw->label != NO_LABEL && map->label == lw->label))) { + if (lw && (map->label == NO_LABEL || map->label == lw->label)) { /* LRl.4: delete record of outstanding lbl withdraw */ lde_wdraw_del(ln, lw); } @@ -707,6 +705,9 @@ lde_check_withdraw(struct map *map, struct lde_nbr *ln) default: break; } + if (map->label != NO_LABEL && map->label != fnh->remote_label) + continue; + lde_send_delete_klabel(fn, fnh); fnh->remote_label = NO_LABEL; } @@ -751,6 +752,10 @@ lde_check_withdraw_wcard(struct map *map, struct lde_nbr *ln) default: break; } + if (map->label != NO_LABEL && map->label != + fnh->remote_label) + continue; + lde_send_delete_klabel(fn, fnh); fnh->remote_label = NO_LABEL; } -- 2.39.5