isisd: Prepare IS-IS for Link State support

In order to provide Link State Traffic Engineering features to IS-IS, this
patch adds some modifications to base IS-IS:

- Solve bug in lsp iterate function to avoid infinite loop in isis_lsp.c by
  adding condition to recurse call
- Add new trigger event to parse LSP in isis_lsp.c
- Add new TE debug flag to track Traffic Engineering events in isisd.[c,h]
- Correct small bug in isis_tlvs.c where delay and min/max delay are not
  correctly handle
- Handle Opaque LSA Traffic Engineering Zebra API in isis_zebra.[c,h]

Signed-off-by: Olivier Dugeon <olivier.dugeon@orange.com>

isisd/isis_lsp.c

@@ -124,6 +124,8 @@ static void lsp_destroy(struct isis_lsp *lsp)
 
 	ISIS_FLAGS_CLEAR_ALL(lsp->SSNflags);
 
+	isis_te_lsp_event(lsp, LSP_DEL);
+
 	lsp_clear_data(lsp);
 
 	if (!LSP_FRAGMENT(lsp->hdr.lsp_id)) {
@@ -335,6 +337,7 @@ void lsp_inc_seqno(struct isis_lsp *lsp, uint32_t seqno)
 
 	lsp_pack_pdu(lsp);
 	isis_spf_schedule(lsp->area, lsp->level);
+	isis_te_lsp_event(lsp, LSP_INC);
 }
 
 static void lsp_purge_add_poi(struct isis_lsp *lsp,
@@ -570,8 +573,10 @@ void lsp_update(struct isis_lsp *lsp, struct isis_lsp_hdr *hdr,
 			lsp_link_fragment(lsp, lsp0);
 	}
 
-	if (lsp->hdr.seqno)
+	if (lsp->hdr.seqno) {
 		isis_spf_schedule(lsp->area, lsp->level);
+		isis_te_lsp_event(lsp, LSP_UPD);
+	}
 }
 
 /* creation of LSP directly from what we received */
@@ -636,8 +641,10 @@ struct isis_lsp *lsp_new(struct isis_area *area, uint8_t *lsp_id,
 void lsp_insert(struct lspdb_head *head, struct isis_lsp *lsp)
 {
 	lspdb_add(head, lsp);
-	if (lsp->hdr.seqno)
+	if (lsp->hdr.seqno) {
 		isis_spf_schedule(lsp->area, lsp->level);
+		isis_te_lsp_event(lsp, LSP_ADD);
+	}
 }
 
 /*
@@ -1030,6 +1037,10 @@ static void lsp_build(struct isis_lsp *lsp, struct isis_area *area)
 			cap.srlb.lower_bound = srdb->config.srlb_lower_bound;
 			/* And finally MSD */
 			cap.msd = srdb->config.msd;
+		} else {
+			/* Disable SR Algorithm */
+			cap.algo[0] = SR_ALGORITHM_UNSET;
+			cap.algo[1] = SR_ALGORITHM_UNSET;
 		}
 
 		isis_tlvs_set_router_capability(lsp->tlvs, &cap);
@@ -2012,6 +2023,7 @@ int lsp_tick(struct thread *thread)
 				/* 7.3.16.4 c) record the time to purge
 				 * FIXME */
 				isis_spf_schedule(lsp->area, lsp->level);
+				isis_te_lsp_event(lsp, LSP_TICK);
 			}
 
 			if (lsp->age_out == 0) {
@@ -2166,7 +2178,7 @@ int isis_lsp_iterate_ip_reach(struct isis_lsp *lsp, int family, uint16_t mtid,
 	if (lsp->hdr.seqno == 0 || lsp->hdr.rem_lifetime == 0)
 		return LSP_ITER_CONTINUE;
 
-	/* Parse main LSP. */
+	/* Parse LSP */
 	if (lsp->tlvs) {
 		if (!fabricd && !pseudo_lsp && family == AF_INET
 		    && mtid == ISIS_MT_IPV4_UNICAST) {
@@ -2236,13 +2248,17 @@ int isis_lsp_iterate_ip_reach(struct isis_lsp *lsp, int family, uint16_t mtid,
 		}
 	}
 
-	/* Parse LSP fragments. */
-	for (ALL_LIST_ELEMENTS_RO(lsp->lspu.frags, node, frag)) {
-		if (!frag->tlvs)
-			continue;
+	/* Parse LSP fragments if it is not a fragment itself */
+	if (!LSP_FRAGMENT(lsp->hdr.lsp_id))
+		for (ALL_LIST_ELEMENTS_RO(lsp->lspu.frags, node, frag)) {
+			if (!frag->tlvs)
+				continue;
 
-		isis_lsp_iterate_ip_reach(frag, family, mtid, cb, arg);
-	}
+			if (isis_lsp_iterate_ip_reach(frag, family, mtid, cb,
+						      arg)
+			    == LSP_ITER_STOP)
+				return LSP_ITER_STOP;
+		}
 
 	return LSP_ITER_CONTINUE;
 }
@@ -2263,7 +2279,7 @@ int isis_lsp_iterate_is_reach(struct isis_lsp *lsp, uint16_t mtid,
 	if (lsp->hdr.seqno == 0 || lsp->hdr.rem_lifetime == 0)
 		return LSP_ITER_CONTINUE;
 
-	/* Parse main LSP. */
+	/* Parse LSP */
 	if (lsp->tlvs) {
 		if (pseudo_lsp || mtid == ISIS_MT_IPV4_UNICAST) {
 			head = lsp->tlvs->oldstyle_reach.head;
@@ -2295,13 +2311,16 @@ int isis_lsp_iterate_is_reach(struct isis_lsp *lsp, uint16_t mtid,
 		}
 	}
 
-	/* Parse LSP fragments. */
-	for (ALL_LIST_ELEMENTS_RO(lsp->lspu.frags, node, frag)) {
-		if (!frag->tlvs)
-			continue;
+	/* Parse LSP fragments if it not a fragment itself. */
+	if (!LSP_FRAGMENT(lsp->hdr.lsp_id))
+		for (ALL_LIST_ELEMENTS_RO(lsp->lspu.frags, node, frag)) {
+			if (!frag->tlvs)
+				continue;
 
-		isis_lsp_iterate_is_reach(frag, mtid, cb, arg);
-	}
+			if (isis_lsp_iterate_is_reach(frag, mtid, cb, arg)
+			    == LSP_ITER_STOP)
+				return LSP_ITER_STOP;
+		}
 
 	return LSP_ITER_CONTINUE;
 }

isisd/isis_zebra.c

@@ -38,6 +38,7 @@
 #include "vrf.h"
 #include "libfrr.h"
 #include "bfd.h"
+#include "link_state.h"
 
 #include "isisd/isis_constants.h"
 #include "isisd/isis_common.h"
@@ -747,13 +748,33 @@ static void isis_zebra_connected(struct zclient *zclient)
 	bfd_client_sendmsg(zclient, ZEBRA_BFD_CLIENT_REGISTER, VRF_DEFAULT);
 }
 
+/**
+ * Register / unregister Link State ZAPI Opaque Message
+ *
+ * @param up	True to register, false to unregister
+ *
+ * @return	0 if success, -1 otherwise
+ */
+int isis_zebra_ls_register(bool up)
+{
+	int rc;
+
+	if (up)
+		rc = ls_register(zclient, true);
+	else
+		rc = ls_unregister(zclient, true);
+
+	return rc;
+}
+
 /*
  * opaque messages between processes
  */
 static int isis_opaque_msg_handler(ZAPI_CALLBACK_ARGS)
 {
 	struct stream *s;
 	struct zapi_opaque_msg info;
+	struct zapi_opaque_reg_info dst;
 	struct ldp_igp_sync_if_state state;
 	struct ldp_igp_sync_announce announce;
 	struct zapi_rlfa_response rlfa;
@@ -764,6 +785,13 @@ static int isis_opaque_msg_handler(ZAPI_CALLBACK_ARGS)
 		return -1;
 
 	switch (info.type) {
+	case LINK_STATE_SYNC:
+		STREAM_GETC(s, dst.proto);
+		STREAM_GETW(s, dst.instance);
+		STREAM_GETL(s, dst.session_id);
+		dst.type = LINK_STATE_SYNC;
+		ret = isis_te_sync_ted(dst);
+		break;
 	case LDP_IGP_SYNC_IF_STATE_UPDATE:
 		STREAM_GET(&state, s, sizeof(state));
 		ret = isis_ldp_sync_state_update(state);

isisd/isis_zebra.h

@@ -67,5 +67,6 @@ int isis_zebra_request_label_range(uint32_t base, uint32_t chunk_size);
 int isis_zebra_release_label_range(uint32_t start, uint32_t end);
 void isis_zebra_vrf_register(struct isis *isis);
 void isis_zebra_vrf_deregister(struct isis *isis);
+int isis_zebra_ls_register(bool up);
 
 #endif /* _ZEBRA_ISIS_ZEBRA_H */

isisd/isisd.c

@@ -81,6 +81,7 @@ unsigned long debug_tx_queue;
 unsigned long debug_sr;
 unsigned long debug_ldp_sync;
 unsigned long debug_lfa;
+unsigned long debug_te;
 
 DEFINE_MGROUP(ISISD, "isisd");
 
@@ -1419,6 +1420,10 @@ void print_debug(struct vty *vty, int flags, int onoff)
 	if (flags & DEBUG_SR)
 		vty_out(vty, "IS-IS Segment Routing events debugging is %s\n",
 			onoffs);
+	if (flags & DEBUG_TE)
+		vty_out(vty,
+			"IS-IS Traffic Engineering events debugging is %s\n",
+			onoffs);
 	if (flags & DEBUG_LFA)
 		vty_out(vty, "IS-IS LFA events debugging is %s\n", onoffs);
 	if (flags & DEBUG_UPDATE_PACKETS)
@@ -1461,6 +1466,8 @@ DEFUN_NOSH (show_debugging,
 		print_debug(vty, DEBUG_SPF_EVENTS, 1);
 	if (IS_DEBUG_SR)
 		print_debug(vty, DEBUG_SR, 1);
+	if (IS_DEBUG_TE)
+		print_debug(vty, DEBUG_TE, 1);
 	if (IS_DEBUG_UPDATE_PACKETS)
 		print_debug(vty, DEBUG_UPDATE_PACKETS, 1);
 	if (IS_DEBUG_RTE_EVENTS)
@@ -1518,6 +1525,10 @@ static int config_write_debug(struct vty *vty)
 		vty_out(vty, "debug " PROTO_NAME " sr-events\n");
 		write++;
 	}
+	if (IS_DEBUG_TE) {
+		vty_out(vty, "debug " PROTO_NAME " te-events\n");
+		write++;
+	}
 	if (IS_DEBUG_LFA) {
 		vty_out(vty, "debug " PROTO_NAME " lfa\n");
 		write++;
@@ -1752,6 +1763,33 @@ DEFUN (no_debug_isis_srevents,
 	return CMD_SUCCESS;
 }
 
+DEFUN (debug_isis_teevents,
+       debug_isis_teevents_cmd,
+       "debug " PROTO_NAME " te-events",
+       DEBUG_STR
+       PROTO_HELP
+       "IS-IS Traffic Engineering Events\n")
+{
+	debug_te |= DEBUG_TE;
+	print_debug(vty, DEBUG_TE, 1);
+
+	return CMD_SUCCESS;
+}
+
+DEFUN (no_debug_isis_teevents,
+       no_debug_isis_teevents_cmd,
+       "no debug " PROTO_NAME " te-events",
+       NO_STR
+       UNDEBUG_STR
+       PROTO_HELP
+       "IS-IS Traffic Engineering Events\n")
+{
+	debug_te &= ~DEBUG_TE;
+	print_debug(vty, DEBUG_TE, 0);
+
+	return CMD_SUCCESS;
+}
+
 DEFUN (debug_isis_lfa,
        debug_isis_lfa_cmd,
        "debug " PROTO_NAME " lfa",
@@ -3140,6 +3178,8 @@ void isis_init(void)
 	install_element(ENABLE_NODE, &no_debug_isis_spfevents_cmd);
 	install_element(ENABLE_NODE, &debug_isis_srevents_cmd);
 	install_element(ENABLE_NODE, &no_debug_isis_srevents_cmd);
+	install_element(ENABLE_NODE, &debug_isis_teevents_cmd);
+	install_element(ENABLE_NODE, &no_debug_isis_teevents_cmd);
 	install_element(ENABLE_NODE, &debug_isis_lfa_cmd);
 	install_element(ENABLE_NODE, &no_debug_isis_lfa_cmd);
 	install_element(ENABLE_NODE, &debug_isis_rtevents_cmd);
@@ -3171,6 +3211,8 @@ void isis_init(void)
 	install_element(CONFIG_NODE, &no_debug_isis_spfevents_cmd);
 	install_element(CONFIG_NODE, &debug_isis_srevents_cmd);
 	install_element(CONFIG_NODE, &no_debug_isis_srevents_cmd);
+	install_element(CONFIG_NODE, &debug_isis_teevents_cmd);
+	install_element(CONFIG_NODE, &no_debug_isis_teevents_cmd);
 	install_element(CONFIG_NODE, &debug_isis_lfa_cmd);
 	install_element(CONFIG_NODE, &no_debug_isis_lfa_cmd);
 	install_element(CONFIG_NODE, &debug_isis_rtevents_cmd);

isisd/isisd.h

@@ -331,6 +331,7 @@ extern unsigned long debug_tx_queue;
 extern unsigned long debug_sr;
 extern unsigned long debug_ldp_sync;
 extern unsigned long debug_lfa;
+extern unsigned long debug_te;
 
 #define DEBUG_ADJ_PACKETS                (1<<0)
 #define DEBUG_SNP_PACKETS                (1<<1)
@@ -347,6 +348,7 @@ extern unsigned long debug_lfa;
 #define DEBUG_SR                         (1<<12)
 #define DEBUG_LDP_SYNC                   (1<<13)
 #define DEBUG_LFA                        (1<<14)
+#define DEBUG_TE                         (1<<15)
 
 /* Debug related macro. */
 #define IS_DEBUG_ADJ_PACKETS (debug_adj_pkt & DEBUG_ADJ_PACKETS)
@@ -364,6 +366,7 @@ extern unsigned long debug_lfa;
 #define IS_DEBUG_SR (debug_sr & DEBUG_SR)
 #define IS_DEBUG_LDP_SYNC (debug_ldp_sync & DEBUG_LDP_SYNC)
 #define IS_DEBUG_LFA (debug_lfa & DEBUG_LFA)
+#define IS_DEBUG_TE (debug_te & DEBUG_TE)
 
 #define lsp_debug(...)                                                         \
 	do {                                                                   \
@@ -383,6 +386,10 @@ extern unsigned long debug_lfa;
 			zlog_debug(__VA_ARGS__);                               \
 	} while (0)
 
-#define DEBUG_TE                         DEBUG_LSP_GEN
+#define te_debug(...)                                                          \
+	do {                                                                   \
+		if (IS_DEBUG_TE)                                               \
+			zlog_debug(__VA_ARGS__);                               \
+	} while (0)
 
 #endif /* ISISD_H */