pimd: Add a flag to decide PIM has to send Hello

Problem Statement:
==================
pim maintains two counters hello tx and hello rx at interface level.
At present pim needs to send the hello message prior to other pim
message as per RFC. This logic is getting derived from the tx hello
counters. So when a new neighbor is added, tx counters are set to
zero and then based on this, it is further decided to send hello in
pim_hello_require function.

Fix:
====
Separating the hello statistics and the logic to decide when to send hello
based on a new flag. pim_ifstat_hello_sent will be used to note down
the hello stats while a new flag is added to decide whether to send hello
or not if it is the first packet to a neighbor.

Signed-off-by: Mobashshera Rasool <mrasool@vmware.com>

5 files changed, 37 insertions, 3 deletions

diff --git a/pimd/pim_hello.c b/pimd/pim_hello.c
index e48a4bdd4..45ea6a956 100644
--- a/pimd/pim_hello.c
+++ b/pimd/pim_hello.c
@@ -545,7 +545,7 @@ void pim_hello_require(struct interface *ifp)
 
 	assert(pim_ifp);
 
-	if (pim_ifp->pim_ifstat_hello_sent)
+	if (PIM_IF_FLAG_TEST_HELLO_SENT(pim_ifp->flags))
 		return;
 
 	pim_hello_restart_now(ifp); /* Send hello and restart timer */
diff --git a/pimd/pim_iface.c b/pimd/pim_iface.c
index eb19cf4dd..4b87bde28 100644
--- a/pimd/pim_iface.c
+++ b/pimd/pim_iface.c
@@ -290,6 +290,7 @@ static void pim_addr_change(struct interface *ifp)
 	  -- FIXME See TODO T31
 	 */
 	pim_ifp->pim_ifstat_hello_sent = 0; /* reset hello counter */
+	PIM_IF_FLAG_UNSET_HELLO_SENT(pim_ifp->flags);
 	if (pim_ifp->pim_sock_fd < 0)
 		return;
 	pim_hello_restart_now(ifp); /* send hello and restart timer */
@@ -1697,8 +1698,10 @@ int pim_ifp_down(struct interface *ifp)
 		}
 	}
 
-	if (ifp->info)
+	if (ifp->info) {
 		pim_if_del_vif(ifp);
+		pim_ifstat_reset(ifp);
+	}
 
 	return 0;
 }
diff --git a/pimd/pim_iface.h b/pimd/pim_iface.h
index 55c278d6e..514e158e7 100644
--- a/pimd/pim_iface.h
+++ b/pimd/pim_iface.h
@@ -61,6 +61,20 @@
 #define PIM_I_am_DR(pim_ifp) (pim_ifp)->pim_dr_addr.s_addr == (pim_ifp)->primary_address.s_addr
 #define PIM_I_am_DualActive(pim_ifp) (pim_ifp)->activeactive == true
 
+/* Macros for interface flags */
+
+/*
+ * PIM needs to know if hello is required to send before other PIM messages
+ * like Join, prune, assert would go out
+ */
+#define PIM_IF_FLAG_HELLO_SENT (1 << 0)
+
+#define PIM_IF_FLAG_TEST_HELLO_SENT(flags) ((flags)&PIM_IF_FLAG_HELLO_SENT)
+
+#define PIM_IF_FLAG_SET_HELLO_SENT(flags) ((flags) |= PIM_IF_FLAG_HELLO_SENT)
+
+#define PIM_IF_FLAG_UNSET_HELLO_SENT(flags) ((flags) &= ~PIM_IF_FLAG_HELLO_SENT)
+
 struct pim_iface_upstream_switch {
 	struct in_addr address;
 	struct list *us;
@@ -161,6 +175,7 @@ struct pim_interface {
 	uint32_t pim_ifstat_bsm_cfg_miss;
 	uint32_t pim_ifstat_ucast_bsm_cfg_miss;
 	uint32_t pim_ifstat_bsm_invalid_sz;
+	uint8_t flags;
 	bool bsm_enable; /* bsm processing enable */
 	bool ucast_bsm_accept; /* ucast bsm processing */
 
diff --git a/pimd/pim_neighbor.c b/pimd/pim_neighbor.c
index 571173c62..530c2e429 100644
--- a/pimd/pim_neighbor.c
+++ b/pimd/pim_neighbor.c
@@ -341,7 +341,7 @@ pim_neighbor_new(struct interface *ifp, struct in_addr source_addr,
 	 * reset the value so that we can know to hurry up and
 	 * hello
 	 */
-	pim_ifp->pim_ifstat_hello_sent = 0;
+	PIM_IF_FLAG_UNSET_HELLO_SENT(pim_ifp->flags);
 
 	pim_inet4_dump("<src?>", source_addr, src_str, sizeof(src_str));
 
diff --git a/pimd/pim_pim.c b/pimd/pim_pim.c
index 8c38cf6c4..5c3c4c23f 100644
--- a/pimd/pim_pim.c
+++ b/pimd/pim_pim.c
@@ -455,6 +455,21 @@ void pim_ifstat_reset(struct interface *ifp)
 	pim_ifp->pim_ifstat_hello_sendfail = 0;
 	pim_ifp->pim_ifstat_hello_recv = 0;
 	pim_ifp->pim_ifstat_hello_recvfail = 0;
+	pim_ifp->pim_ifstat_bsm_rx = 0;
+	pim_ifp->pim_ifstat_bsm_tx = 0;
+	pim_ifp->pim_ifstat_join_recv = 0;
+	pim_ifp->pim_ifstat_join_send = 0;
+	pim_ifp->pim_ifstat_prune_recv = 0;
+	pim_ifp->pim_ifstat_prune_send = 0;
+	pim_ifp->pim_ifstat_reg_recv = 0;
+	pim_ifp->pim_ifstat_reg_send = 0;
+	pim_ifp->pim_ifstat_reg_stop_recv = 0;
+	pim_ifp->pim_ifstat_reg_stop_send = 0;
+	pim_ifp->pim_ifstat_assert_recv = 0;
+	pim_ifp->pim_ifstat_assert_send = 0;
+	pim_ifp->pim_ifstat_bsm_cfg_miss = 0;
+	pim_ifp->pim_ifstat_ucast_bsm_cfg_miss = 0;
+	pim_ifp->pim_ifstat_bsm_invalid_sz = 0;
 }
 
 void pim_sock_reset(struct interface *ifp)
@@ -707,6 +722,7 @@ int pim_hello_send(struct interface *ifp, uint16_t holdtime)
 	}
 
 	++pim_ifp->pim_ifstat_hello_sent;
+	PIM_IF_FLAG_SET_HELLO_SENT(pim_ifp->flags);
 
 	return 0;
 }