From 06fb60c4af38d529d20b662748243b3f4a693c60 Mon Sep 17 00:00:00 2001 From: Ondrej Zajicek Date: Wed, 30 Mar 2011 01:09:18 +0200 Subject: Fixes some problems in BGP error handling. --- proto/bgp/packets.c | 147 ++++++++++++++++++++++++++++++---------------------- 1 file changed, 86 insertions(+), 61 deletions(-) (limited to 'proto/bgp/packets.c') diff --git a/proto/bgp/packets.c b/proto/bgp/packets.c index bf98640..0b41244 100644 --- a/proto/bgp/packets.c +++ b/proto/bgp/packets.c @@ -790,9 +790,9 @@ bgp_rx_open(struct bgp_conn *conn, byte *pkt, int len) int b = *pp++; \ int q; \ ll--; \ - if (b > BITS_PER_IP_ADDRESS) { err=10; goto bad; } \ + if (b > BITS_PER_IP_ADDRESS) { err=10; goto done; } \ q = (b+7) / 8; \ - if (ll < q) { err=1; goto bad; } \ + if (ll < q) { err=1; goto done; } \ memcpy(&prefix, pp, q); \ pp += q; \ ll -= q; \ @@ -840,11 +840,10 @@ bgp_do_rx_update(struct bgp_conn *conn, byte *attrs, int attr_len) { struct bgp_proto *p = conn->bgp; - rta *a0; - rta *a = NULL; - ip_addr prefix; net *n; - int err = 0, pxlen; + rta *a0, *a = NULL; + ip_addr prefix; + int pxlen, err = 0; /* Withdraw routes */ while (withdrawn_len) @@ -859,32 +858,43 @@ bgp_do_rx_update(struct bgp_conn *conn, return; a0 = bgp_decode_attrs(conn, attrs, attr_len, bgp_linpool, nlri_len); - if (a0 && nlri_len && bgp_set_next_hop(p, a0)) + + if (conn->state != BS_ESTABLISHED) /* fatal error during decoding */ + return; + + if (a0 && bgp_set_next_hop(p, a0)) + a = rta_lookup(a0); + + while (nlri_len) { - a = rta_lookup(a0); - while (nlri_len) + DECODE_PREFIX(nlri, nlri_len); + DBG("Add %I/%d\n", prefix, pxlen); + + if (a) { - rte *e; - DECODE_PREFIX(nlri, nlri_len); - DBG("Add %I/%d\n", prefix, pxlen); - e = rte_get_temp(rta_clone(a)); - n = net_get(p->p.table, prefix, pxlen); - e->net = n; + rte *e = rte_get_temp(rta_clone(a)); + e->net = net_get(p->p.table, prefix, pxlen); e->pflags = 0; - rte_update(p->p.table, n, &p->p, &p->p, e); - if (bgp_apply_limits(p) < 0) - goto bad2; + rte_update(p->p.table, e->net, &p->p, &p->p, e); + } + else + { + /* Forced withdraw as a result of soft error */ + if (n = net_find(p->p.table, prefix, pxlen)) + rte_update(p->p.table, n, &p->p, &p->p, NULL); } - rta_free(a); - } - return; + if (bgp_apply_limits(p) < 0) + goto done; + } - bad: - bgp_error(conn, 3, err, NULL, 0); - bad2: + done: if (a) rta_free(a); + + if (err) + bgp_error(conn, 3, err, NULL, 0); + return; } @@ -895,7 +905,7 @@ bgp_do_rx_update(struct bgp_conn *conn, len = len0 = p->name##_len; \ if (len) \ { \ - if (len < 3) goto bad; \ + if (len < 3) { err=9; goto done; } \ af = get_u16(x); \ sub = x[2]; \ x += 3; \ @@ -906,6 +916,24 @@ bgp_do_rx_update(struct bgp_conn *conn, af = 0; \ if (af == BGP_AF_IPV6) +static void +bgp_attach_next_hop(rta *a0, byte *x) +{ + ip_addr *nh = (ip_addr *) bgp_attach_attr_wa(&a0->eattrs, bgp_linpool, BA_NEXT_HOP, NEXT_HOP_LENGTH); + memcpy(nh, x+1, 16); + ipa_ntoh(nh[0]); + + /* We store received link local address in the other part of BA_NEXT_HOP eattr. */ + if (*x == 32) + { + memcpy(nh+1, x+17, 16); + ipa_ntoh(nh[1]); + } + else + nh[1] = IPA_NONE; +} + + static void bgp_do_rx_update(struct bgp_conn *conn, byte *withdrawn, int withdrawn_len, @@ -916,16 +944,16 @@ bgp_do_rx_update(struct bgp_conn *conn, byte *start, *x; int len, len0; unsigned af, sub; - rta *a0; - rta *a = NULL; - ip_addr prefix; net *n; - int err = 0, pxlen; + rta *a0, *a = NULL; + ip_addr prefix; + int pxlen, err = 0; p->mp_reach_len = 0; p->mp_unreach_len = 0; a0 = bgp_decode_attrs(conn, attrs, attr_len, bgp_linpool, 0); - if (!a0) + + if (conn->state != BS_ESTABLISHED) /* fatal error during decoding */ return; DO_NLRI(mp_unreach) @@ -943,52 +971,49 @@ bgp_do_rx_update(struct bgp_conn *conn, { /* Create fake NEXT_HOP attribute */ if (len < 1 || (*x != 16 && *x != 32) || len < *x + 2) - goto bad; + { err = 9; goto done; } - ip_addr *nh = (ip_addr *) bgp_attach_attr_wa(&a0->eattrs, bgp_linpool, BA_NEXT_HOP, NEXT_HOP_LENGTH); - memcpy(nh, x+1, 16); - ipa_ntoh(nh[0]); - - /* We store received link local address in the other part of BA_NEXT_HOP eattr. */ - if (*x == 32) - { - memcpy(nh+1, x+17, 16); - ipa_ntoh(nh[1]); - } - else - nh[1] = IPA_NONE; + if (a0) + bgp_attach_next_hop(a0, x); /* Also ignore one reserved byte */ len -= *x + 2; x += *x + 2; - if (bgp_set_next_hop(p, a0)) + if (a0 && bgp_set_next_hop(p, a0)) + a = rta_lookup(a0); + + while (len) { - a = rta_lookup(a0); - while (len) + DECODE_PREFIX(x, len); + DBG("Add %I/%d\n", prefix, pxlen); + + if (a) { - rte *e; - DECODE_PREFIX(x, len); - DBG("Add %I/%d\n", prefix, pxlen); - e = rte_get_temp(rta_clone(a)); - n = net_get(p->p.table, prefix, pxlen); - e->net = n; + rte *e = rte_get_temp(rta_clone(a)); + e->net = net_get(p->p.table, prefix, pxlen); e->pflags = 0; - rte_update(p->p.table, n, &p->p, &p->p, e); - if (bgp_apply_limits(p) < 0) - goto bad2; + rte_update(p->p.table, e->net, &p->p, &p->p, e); + } + else + { + /* Forced withdraw as a result of soft error */ + if (n = net_find(p->p.table, prefix, pxlen)) + rte_update(p->p.table, n, &p->p, &p->p, NULL); } - rta_free(a); + + if (bgp_apply_limits(p) < 0) + goto done; } } - return; - - bad: - bgp_error(conn, 3, 9, start, len0); - bad2: + done: if (a) rta_free(a); + + if (err) /* Use subcode 9, not err */ + bgp_error(conn, 3, 9, NULL, 0); + return; } -- cgit v1.2.3