From: Christian Franke <[email protected]>
Signed-off-by: Christian Franke <[email protected]>
---
isisd/isis_lsp.c | 14 +++++++++++++-
isisd/isis_pdu.c | 32 +++++++++++++++++++++++++++-----
2 files changed, 40 insertions(+), 6 deletions(-)
diff --git a/isisd/isis_lsp.c b/isisd/isis_lsp.c
index d42aa30..e9eaafa 100644
--- a/isisd/isis_lsp.c
+++ b/isisd/isis_lsp.c
@@ -273,7 +273,19 @@ lsp_compare (char *areatag, struct isis_lsp *lsp,
u_int32_t seq_num,
return LSP_EQUAL;
}
- if (ntohl (seq_num) >= ntohl (lsp->lsp_header->seq_num))
+ /*
+ * LSPs with identical checksums should only be treated as newer if:
+ * a) The current LSP has a remaining lifetime != 0 and the other LSP has a
+ * remaining lifetime == 0. In this case, we should participate in the
purge
+ * and should not treat the current LSP with remaining lifetime == 0 as
older.
+ * b) The LSP has an incorrect checksum. In this case, we need to react as
given
+ * in 7.3.16.2.
+ */
+ if (ntohl (seq_num) > ntohl (lsp->lsp_header->seq_num)
+ || (ntohl(seq_num) == ntohl(lsp->lsp_header->seq_num)
+ && ( (lsp->lsp_header->rem_lifetime != 0
+ && rem_lifetime == 0)
+ || lsp->lsp_header->checksum != checksum)))
{
if (isis->debugs & DEBUG_SNP_PACKETS)
{
diff --git a/isisd/isis_pdu.c b/isisd/isis_pdu.c
index d2be27b..bbf0d73 100644
--- a/isisd/isis_pdu.c
+++ b/isisd/isis_pdu.c
@@ -1309,6 +1309,7 @@ process_lsp (int level, struct isis_circuit *circuit,
const u_char *ssnpa)
u_char lspid[ISIS_SYS_ID_LEN + 2];
struct isis_passwd *passwd;
uint16_t pdu_len;
+ int lsp_confusion;
if (isis->debugs & DEBUG_UPDATE_PACKETS)
{
@@ -1483,6 +1484,21 @@ dontcheckadj:
/* 7.3.15.1 a) 9 - OriginatingLSPBufferSize - not implemented FIXME: do it
*/
+ /* 7.3.16.2 - If this is an LSP from another IS with identical seq_num but
+ * wrong checksum, initiate a purge. */
+ if (lsp
+ && (lsp->lsp_header->seq_num == hdr->seq_num)
+ && (lsp->lsp_header->checksum != hdr->checksum))
+ {
+ zlog_warn("ISIS-Upd (%s): LSP %s seq 0x%08x with confused checksum
received.",
+ circuit->area->area_tag, rawlspid_print(hdr->lsp_id),
+ ntohl(hdr->seq_num));
+ hdr->rem_lifetime = 0;
+ lsp_confusion = 1;
+ }
+ else
+ lsp_confusion = 0;
+
/* 7.3.15.1 b) - If the remaining life time is 0, we perform 7.3.16.4 */
if (hdr->rem_lifetime == 0)
{
@@ -1505,14 +1521,20 @@ dontcheckadj:
lsp_update (lsp, circuit->rcv_stream, circuit->area, level);
/* ii */
lsp_set_all_srmflags (lsp);
- /* iii */
- ISIS_CLEAR_FLAG (lsp->SRMflags, circuit);
/* v */
ISIS_FLAGS_CLEAR_ALL (lsp->SSNflags); /* FIXME: OTHER than c
*/
- /* iv */
- if (circuit->circ_type != CIRCUIT_T_BROADCAST)
- ISIS_SET_FLAG (lsp->SSNflags, circuit);
+ /* For the case of lsp confusion, flood the purge back to its
+ * originator so that it can react. Otherwise, don't reflood
+ * through incoming circuit as usual */
+ if (!lsp_confusion)
+ {
+ /* iii */
+ ISIS_CLEAR_FLAG (lsp->SRMflags, circuit);
+ /* iv */
+ if (circuit->circ_type != CIRCUIT_T_BROADCAST)
+ ISIS_SET_FLAG (lsp->SSNflags, circuit);
+ }
} /* 7.3.16.4 b) 2) */
else if (comp == LSP_EQUAL)
{
--
2.6.1
_______________________________________________
Quagga-dev mailing list
[email protected]
https://lists.quagga.net/mailman/listinfo/quagga-dev
