From b21b068dc9066197fc499801eb386c373a743a92 Mon Sep 17 00:00:00 2001
From: Emanuele Di Pascale <emanuele@voltanet.io>
Date: Wed, 14 Nov 2018 15:08:26 +0100
Subject: [PATCH] isisd: implement the 'attempt-to-exceed-max-sequence'
 notification

Signed-off-by: Emanuele Di Pascale <emanuele@voltanet.io>
---
 isisd/isis_lsp.c        |  9 +++++++++
 isisd/isis_northbound.c | 19 +++++++++++++++++++
 isisd/isisd.h           |  2 ++
 3 files changed, 30 insertions(+)

diff --git a/isisd/isis_lsp.c b/isisd/isis_lsp.c
index 8d393c7a08..8b2af9975c 100644
--- a/isisd/isis_lsp.c
+++ b/isisd/isis_lsp.c
@@ -355,6 +355,15 @@ void lsp_inc_seqno(struct isis_lsp *lsp, uint32_t seqno)
 	else
 		newseq = seqno + 1;
 
+#ifndef FABRICD
+	/* check for overflow */
+	if (newseq < lsp->hdr.seqno) {
+		/* send northbound notification */
+		isis_notif_lsp_exceed_max(lsp->area,
+					  rawlspid_print(lsp->hdr.lsp_id));
+	}
+#endif /* ifndef FABRICD */
+
 	lsp->hdr.seqno = newseq;
 
 	lsp_pack_pdu(lsp);
diff --git a/isisd/isis_northbound.c b/isisd/isis_northbound.c
index 136fec2375..c112c64ca1 100644
--- a/isisd/isis_northbound.c
+++ b/isisd/isis_northbound.c
@@ -2569,6 +2569,25 @@ void isis_notif_corrupted_lsp(const struct isis_area *area, const char *lsp_id)
 	nb_notification_send(xpath, arguments);
 }
 
+/*
+ * XPath:
+ * /frr-isisd:attempt-to-exceed-max-sequence
+ */
+void isis_notif_lsp_exceed_max(const struct isis_area *area, const char *lsp_id)
+{
+	const char *xpath = "/frr-isisd:attempt-to-exceed-max-sequence";
+	struct list *arguments = yang_data_list_new();
+	char xpath_arg[XPATH_MAXLEN];
+	struct yang_data *data;
+
+	notif_prep_instance_hdr(xpath, area, "default", arguments);
+	snprintf(xpath_arg, sizeof(xpath_arg), "%s/lsp-id", xpath);
+	data = yang_data_new_string(xpath_arg, lsp_id);
+	listnode_add(arguments, data);
+
+	nb_notification_send(xpath, arguments);
+}
+
 /* clang-format off */
 const struct frr_yang_module_info frr_isisd_info = {
 	.name = "frr-isisd",
diff --git a/isisd/isisd.h b/isisd/isisd.h
index 12d3f2bec2..6f32dbdd58 100644
--- a/isisd/isisd.h
+++ b/isisd/isisd.h
@@ -229,6 +229,8 @@ extern void isis_notif_if_state_change(const struct isis_circuit *circuit,
 				       bool down);
 extern void isis_notif_corrupted_lsp(const struct isis_area *area,
 				     const char *lsp_id); /* currently unused */
+extern void isis_notif_lsp_exceed_max(const struct isis_area *area,
+				      const char *lsp_id);
 /* Master of threads. */
 extern struct thread_master *master;
 
-- 
2.39.5