[PATCH v2] mesh: Sequence number related fixes

[PATCH v2] mesh: Sequence number related fixes

[Jakub Witowski]

---
 mesh/crypto.c           |  3 +++
 mesh/mesh-config-json.c | 10 +++++++++-
 mesh/net.c              |  6 ++++++
 3 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/mesh/crypto.c b/mesh/crypto.c
index 8ea906ac9..596a289f9 100644
--- a/mesh/crypto.c
+++ b/mesh/crypto.c
@@ -637,6 +637,9 @@ bool mesh_crypto_packet_build(bool ctl, uint8_t ttl,
 	uint32_t hdr;
 	size_t n;
 
+	if (seq > SEQ_MASK)
+		return false;
+
 	l_put_be32(seq, packet + 1);
 	packet[1] = (ctl ? CTL : 0) | (ttl & TTL_MASK);
 
diff --git a/mesh/mesh-config-json.c b/mesh/mesh-config-json.c
index 755caab0e..0abb77b36 100644
--- a/mesh/mesh-config-json.c
+++ b/mesh/mesh-config-json.c
@@ -40,6 +40,7 @@
 #include "mesh/mesh-defs.h"
 #include "mesh/util.h"
 #include "mesh/mesh-config.h"
+#include "mesh/net.h"
 
 /* To prevent local node JSON cache thrashing, minimum update times */
 #define MIN_SEQ_CACHE_TRIGGER	32
@@ -365,7 +366,7 @@ static bool read_seq_number(json_object *jobj, uint32_t *seq_number)
 	if (!val && errno == EINVAL)
 		return false;
 
-	if (val < 0 || val > 0xffffff)
+	if (val < 0 || val > SEQ_MASK + 1)
 		return false;
 
 	*seq_number = (uint32_t) val;
@@ -2019,6 +2020,13 @@ bool mesh_config_write_seq_number(struct mesh_config *cfg, uint32_t seq,
 		if (cached < seq + MIN_SEQ_CACHE_VALUE)
 			cached = seq + MIN_SEQ_CACHE_VALUE;
 
+		/* when the cached exceeds the max allowed seq nr value,
+		 * update it with out of range value in order not to send
+		 * again the message with max seq nr after application crash
+		 */
+		if (cached > SEQ_MASK)
+			cached = SEQ_MASK + 1;
+
 		l_debug("Seq Cache: %d -> %d", seq, cached);
 
 		cfg->write_seq = seq;
diff --git a/mesh/net.c b/mesh/net.c
index f0f0dbdbd..530a41ee5 100644
--- a/mesh/net.c
+++ b/mesh/net.c
@@ -511,6 +511,12 @@ uint32_t mesh_net_next_seq_num(struct mesh_net *net)
 {
 	uint32_t seq = net->seq_num++;
 
+	/* Exceed the seq_nr max value in order
+	 * not to send duplicated messages with the same max seq_nr
+	 */
+	if (net->seq_num > SEQ_MASK)
+		net->seq_num = SEQ_MASK + 1;
+
 	node_set_sequence_number(net->node, net->seq_num);
 	return seq;
 }
-- 
2.20.1