bfdd: generate random session identificators

This also avoids returning `session_id == 0` which should not happen.

Signed-off-by: Rafael Zalamena <rzalamena@opensourcerouting.org>

diff --git a/bfdd/bfd.c b/bfdd/bfd.c
index c092b672d30684e89b269557f5798a1ad43d07ca..aa09d0be4ac26a8be9fb5cb1fbe56cdd2a9a0e39 100644 (file)
--- a/bfdd/bfd.c
+++ b/bfdd/bfd.c
@@ -100,9 +100,18 @@ struct bfd_session *bs_peer_find(struct bfd_peer_cfg *bpc)
 
 static uint32_t ptm_bfd_gen_ID(void)
 {
-       static uint32_t sessionID = 1;
+       uint32_t session_id;
 
-       return (sessionID++);
+       /*
+        * RFC 5880, Section 6.8.1. recommends that we should generate
+        * random session identification numbers.
+        */
+       do {
+               session_id = ((random() << 16) & 0xFFFF0000)
+                            | (random() & 0x0000FFFF);
+       } while (session_id == 0 || bfd_id_lookup(session_id) != NULL);
+
+       return session_id;
 }
 
 void ptm_bfd_start_xmt_timer(struct bfd_session *bfd, bool is_echo)