isisd: add purge originator identification support

Implement RFC 6232, optionally allowing to flood isisd's NET and
hostname in purges it originates.

Signed-off-by: Christian Franke <chris@opensourcerouting.org>

8 files changed, 82 insertions, 17 deletions

diff --git a/doc/user/isisd.rst b/doc/user/isisd.rst
index 54f82f6832..ee681858d1 100644
--- a/doc/user/isisd.rst
+++ b/doc/user/isisd.rst
@@ -106,6 +106,14 @@ writing, *isisd* does not support multiple ISIS processes.
 
    Set overload bit to avoid any transit traffic.
 
+.. index:: purge-originator
+.. clicmd:: purge-originator
+
+.. index:: no purge-originator
+.. clicmd:: no purge-originator
+
+   Enable or disable :rfc:`6232` purge originator identification.
+
 .. _isis-timer:
 
 ISIS Timer
diff --git a/isisd/isis_lsp.c b/isisd/isis_lsp.c
index dc38737923..e8777e9b53 100644
--- a/isisd/isis_lsp.c
+++ b/isisd/isis_lsp.c
@@ -353,7 +353,21 @@ void lsp_inc_seqno(struct isis_lsp *lsp, uint32_t seqno)
 	isis_spf_schedule(lsp->area, lsp->level);
 }
 
-static void lsp_purge(struct isis_lsp *lsp, int level)
+static void lsp_purge_add_poi(struct isis_lsp *lsp,
+			      const uint8_t *sender)
+{
+	if (!lsp->area->purge_originator)
+		return;
+
+	/* add purge originator identification */
+	if (!lsp->tlvs)
+		lsp->tlvs = isis_alloc_tlvs();
+	isis_tlvs_set_purge_originator(lsp->tlvs, isis->sysid, sender);
+	isis_tlvs_set_dynamic_hostname(lsp->tlvs, cmd_hostname_get());
+}
+
+static void lsp_purge(struct isis_lsp *lsp, int level,
+		      const uint8_t *sender)
 {
 	/* reset stream */
 	lsp_clear_data(lsp);
@@ -365,6 +379,8 @@ static void lsp_purge(struct isis_lsp *lsp, int level)
 	lsp->level = level;
 	lsp->age_out = lsp->area->max_lsp_lifetime[level - 1];
 
+	lsp_purge_add_poi(lsp, sender);
+
 	lsp_pack_pdu(lsp);
 	lsp_flood(lsp, NULL);
 }
@@ -386,7 +402,7 @@ static void lsp_seqno_update(struct isis_lsp *lsp0)
 		if (lsp->tlvs)
 			lsp_inc_seqno(lsp, 0);
 		else
-			lsp_purge(lsp, lsp0->level);
+			lsp_purge(lsp, lsp0->level, NULL);
 	}
 
 	return;
@@ -426,7 +442,8 @@ static void lsp_update_data(struct isis_lsp *lsp, struct isis_lsp_hdr *hdr,
 
 	lsp->tlvs = tlvs;
 
-	if (area->dynhostname && lsp->tlvs->hostname) {
+	if (area->dynhostname && lsp->tlvs->hostname
+	    && lsp->hdr.rem_lifetime) {
 		isis_dynhn_insert(lsp->hdr.lsp_id, lsp->tlvs->hostname,
 				  (lsp->hdr.lsp_bits & LSPBIT_IST)
 						  == IS_LEVEL_1_AND_2
@@ -463,10 +480,10 @@ void lsp_update(struct isis_lsp *lsp, struct isis_lsp_hdr *hdr,
 		lsp->own_lsp = 0;
 	}
 
-	lsp_update_data(lsp, hdr, tlvs, stream, area, level);
 	if (confusion) {
-		lsp->hdr.rem_lifetime = hdr->rem_lifetime = 0;
-		put_lsp_hdr(lsp, NULL, true);
+		lsp_purge(lsp, level, NULL);
+	} else {
+		lsp_update_data(lsp, hdr, tlvs, stream, area, level);
 	}
 
 	if (LSP_FRAGMENT(lsp->hdr.lsp_id) && !lsp->lspu.zero_lsp) {
@@ -1865,17 +1882,14 @@ int lsp_tick(struct thread *thread)
 				 */
 				if (rem_lifetime == 1 && lsp->hdr.seqno != 0) {
 					/* 7.3.16.4 a) set SRM flags on all */
-					lsp_flood(lsp, NULL);
-					/* 7.3.16.4 b) retain only the header
-					 * FIXME  */
+					/* 7.3.16.4 b) retain only the header */
+					if (lsp->area->purge_originator)
+						lsp_purge(lsp, lsp->level, NULL);
+					else
+						lsp_flood(lsp, NULL);
 					/* 7.3.16.4 c) record the time to purge
 					 * FIXME */
-					/* run/schedule spf */
-					/* isis_spf_schedule is called inside
-					 * lsp_destroy() below;
-					 * so it is not needed here. */
-					/* isis_spf_schedule (lsp->area,
-					 * lsp->level); */
+					isis_spf_schedule(lsp->area, lsp->level);
 				}
 
 				if (lsp->age_out == 0) {
@@ -1917,7 +1931,7 @@ void lsp_purge_pseudo(uint8_t *id, struct isis_circuit *circuit, int level)
 	if (!lsp)
 		return;
 
-	lsp_purge(lsp, level);
+	lsp_purge(lsp, level, NULL);
 }
 
 /*
@@ -1941,6 +1955,8 @@ void lsp_purge_non_exist(int level, struct isis_lsp_hdr *hdr,
 	memcpy(&lsp->hdr, hdr, sizeof(lsp->hdr));
 	lsp->hdr.rem_lifetime = 0;
 
+	lsp_purge_add_poi(lsp, NULL);
+
 	lsp_pack_pdu(lsp);
 
 	lsp_insert(lsp, area->lspdb[lsp->level - 1]);
diff --git a/isisd/isis_pdu.c b/isisd/isis_pdu.c
index ce050a0c93..8649c5a0c8 100644
--- a/isisd/isis_pdu.c
+++ b/isisd/isis_pdu.c
@@ -900,7 +900,8 @@ dontcheckadj:
 	 * but
 	 *            wrong checksum, initiate a purge. */
 	if (lsp && (lsp->hdr.seqno == hdr.seqno)
-	    && (lsp->hdr.checksum != hdr.checksum)) {
+	    && (lsp->hdr.checksum != hdr.checksum)
+	    && hdr.rem_lifetime) {
 		zlog_warn("ISIS-Upd (%s): LSP %s seq 0x%08" PRIx32
 			  " with confused checksum received.",
 			  circuit->area->area_tag, rawlspid_print(hdr.lsp_id),
diff --git a/isisd/isis_tlvs.c b/isisd/isis_tlvs.c
index 0efe52d0c1..b22460a0b5 100644
--- a/isisd/isis_tlvs.c
+++ b/isisd/isis_tlvs.c
@@ -3697,3 +3697,20 @@ isis_tlvs_lookup_mt_router_info(struct isis_tlvs *tlvs, uint16_t mtid)
 
 	return NULL;
 }
+
+void isis_tlvs_set_purge_originator(struct isis_tlvs *tlvs,
+				    const uint8_t *generator,
+				    const uint8_t *sender)
+{
+	assert(!tlvs->purge_originator);
+
+	tlvs->purge_originator = XCALLOC(MTYPE_ISIS_TLV,
+					 sizeof(*tlvs->purge_originator));
+	memcpy(tlvs->purge_originator->generator, generator,
+	       sizeof(tlvs->purge_originator->generator));
+	if (sender) {
+		tlvs->purge_originator->sender_set = true;
+		memcpy(tlvs->purge_originator->sender, sender,
+		       sizeof(tlvs->purge_originator->sender));
+	}
+}
diff --git a/isisd/isis_tlvs.h b/isisd/isis_tlvs.h
index abdd03f02d..4144809fa3 100644
--- a/isisd/isis_tlvs.h
+++ b/isisd/isis_tlvs.h
@@ -383,4 +383,8 @@ void isis_tlvs_add_spine_leaf(struct isis_tlvs *tlvs, uint8_t tier,
 
 struct isis_mt_router_info *
 isis_tlvs_lookup_mt_router_info(struct isis_tlvs *tlvs, uint16_t mtid);
+
+void isis_tlvs_set_purge_originator(struct isis_tlvs *tlvs,
+				    const uint8_t *generator,
+				    const uint8_t *sender);
 #endif
diff --git a/isisd/isis_vty_common.c b/isisd/isis_vty_common.c
index dbe5beca6e..2b98a88b34 100644
--- a/isisd/isis_vty_common.c
+++ b/isisd/isis_vty_common.c
@@ -568,6 +568,18 @@ DEFUN (no_area_lsp_mtu,
 	return isis_vty_lsp_mtu_set(vty, DEFAULT_LSP_MTU);
 }
 
+DEFUN (area_purge_originator,
+       area_purge_originator_cmd,
+       "[no] purge-originator",
+       NO_STR
+       "Use the RFC 6232 purge-originator\n")
+{
+	VTY_DECLVAR_CONTEXT(isis_area, area);
+
+	area->purge_originator = !!strcmp(argv[0]->text, "no");
+	return CMD_SUCCESS;
+}
+
 int isis_vty_lsp_gen_interval_set(struct vty *vty, int level, uint16_t interval)
 {
 	VTY_DECLVAR_CONTEXT(isis_area, area);
@@ -924,6 +936,8 @@ void isis_vty_init(void)
 	install_element(ROUTER_NODE, &area_lsp_mtu_cmd);
 	install_element(ROUTER_NODE, &no_area_lsp_mtu_cmd);
 
+	install_element(ROUTER_NODE, &area_purge_originator_cmd);
+
 	install_element(ROUTER_NODE, &lsp_gen_interval_cmd);
 	install_element(ROUTER_NODE, &no_lsp_gen_interval_cmd);
 
diff --git a/isisd/isisd.c b/isisd/isisd.c
index 640bd69ce4..e3ff3b8d93 100644
--- a/isisd/isisd.c
+++ b/isisd/isisd.c
@@ -2029,6 +2029,10 @@ int isis_config_write(struct vty *vty)
 				vty_out(vty, " lsp-mtu %u\n", area->lsp_mtu);
 				write++;
 			}
+			if (area->purge_originator) {
+				vty_out(vty, " purge-originator\n");
+				write++;
+			}
 
 			/* Minimum SPF interval. */
 			if (area->min_spf_interval[0]
diff --git a/isisd/isisd.h b/isisd/isisd.h
index cc5def8f56..864021428a 100644
--- a/isisd/isisd.h
+++ b/isisd/isisd.h
@@ -148,6 +148,7 @@ struct isis_area {
 	/* multi topology settings */
 	struct list *mt_settings;
 	int ipv6_circuits;
+	bool purge_originator;
 	/* Counters */
 	uint32_t circuit_state_changes;
 	struct isis_redist redist_settings[REDIST_PROTOCOL_COUNT]