ftfw: shrink alive message size

This patch reduces the size of alive messages by removing the
"from" and "to" fields which are not of any help. This patch also
removes the IS_CTL() macro since it does not return true for
the control messages anymore but only for IS_ACK(), IS_NACK() and
IS_RESYNC().

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

4 files changed, 43 insertions, 6 deletions

diff --git a/include/network.h b/include/network.h
index f9756db..40bb2b2 100644
--- a/include/network.h
+++ b/include/network.h
@@ -29,6 +29,7 @@ int nethdr_align(int len);
 int nethdr_size(int len);
 void nethdr_set(struct nethdr *net, int type);
 void nethdr_set_ack(struct nethdr *net);
+void nethdr_set_ctl(struct nethdr *net);
 
 #define NETHDR_DATA(x)							 \
 	(struct netattr *)(((char *)x) + NETHDR_SIZ)
@@ -102,7 +103,6 @@ ssize_t mcast_buffered_pending_netmsg(struct mcast_sock *m);
 #define IS_NACK(x)	(x->type == NET_T_CTL && x->flags & NET_F_NACK)
 #define IS_RESYNC(x)	(x->type == NET_T_CTL && x->flags & NET_F_RESYNC)
 #define IS_ALIVE(x)	(x->type == NET_T_CTL && x->flags & NET_F_ALIVE)
-#define IS_CTL(x)	IS_ACK(x) || IS_NACK(x) || IS_RESYNC(x) || IS_ALIVE(x)
 #define IS_HELLO(x)	(x->flags & NET_F_HELLO)
 #define IS_HELLO_BACK(x)(x->flags & NET_F_HELLO_BACK)
 
@@ -110,7 +110,7 @@ ssize_t mcast_buffered_pending_netmsg(struct mcast_sock *m);
 ({									\
 	x->len   = ntohs(x->len);					\
 	x->seq   = ntohl(x->seq);					\
-	if (IS_CTL(x)) {						\
+	if (IS_ACK(x) || IS_NACK(x) || IS_RESYNC(x)) {			\
 		struct nethdr_ack *__ack = (struct nethdr_ack *) x;	\
 		__ack->from = ntohl(__ack->from);			\
 		__ack->to = ntohl(__ack->to);				\
@@ -119,7 +119,7 @@ ssize_t mcast_buffered_pending_netmsg(struct mcast_sock *m);
 
 #define HDR_HOST2NETWORK(x)						\
 ({									\
-	if (IS_CTL(x)) {						\
+	if (IS_ACK(x) || IS_NACK(x) || IS_RESYNC(x)) {			\
 		struct nethdr_ack *__ack = (struct nethdr_ack *) x;	\
 		__ack->from = htonl(__ack->from);			\
 		__ack->to = htonl(__ack->to);				\
diff --git a/src/network.c b/src/network.c
index 98df5ea..090dec8 100644
--- a/src/network.c
+++ b/src/network.c
@@ -61,6 +61,11 @@ void nethdr_set_ack(struct nethdr *net)
 	__nethdr_set(net, NETHDR_ACK_SIZ, NET_T_CTL);
 }
 
+void nethdr_set_ctl(struct nethdr *net)
+{
+	__nethdr_set(net, NETHDR_SIZ, NET_T_CTL);
+}
+
 static size_t tx_buflenmax;
 static size_t tx_buflen = 0;
 static char *tx_buf;
diff --git a/src/sync-ftfw.c b/src/sync-ftfw.c
index 014cebd..4758710 100644
--- a/src/sync-ftfw.c
+++ b/src/sync-ftfw.c
@@ -121,6 +121,31 @@ static void tx_queue_add_ctlmsg(uint32_t flags, uint32_t from, uint32_t to)
 	write_evfd(STATE_SYNC(evfd));
 }
 
+static void tx_queue_add_ctlmsg2(uint32_t flags)
+{
+	struct nethdr ctl = {
+		.type  = NET_T_CTL,
+		.flags = flags,
+	};
+
+	switch(hello_state) {
+	case HELLO_INIT:
+		hello_state = HELLO_SAY;
+		/* fall through */
+	case HELLO_SAY:
+		ctl.flags |= NET_F_HELLO;
+		break;
+	}
+
+	if (say_hello_back) {
+		ctl.flags |= NET_F_HELLO_BACK;
+		say_hello_back = 0;
+	}
+
+	queue_add(tx_queue, &ctl, NETHDR_SIZ);
+	write_evfd(STATE_SYNC(evfd));
+}
+
 /* this function is called from the alarm framework */
 static void do_alive_alarm(struct alarm_block *a, void *data)
 {
@@ -131,7 +156,7 @@ static void do_alive_alarm(struct alarm_block *a, void *data)
 				    STATE_SYNC(last_seq_recv));
 		ack_from_set = 0;
 	} else
-		tx_queue_add_ctlmsg(NET_F_ALIVE, 0, 0);
+		tx_queue_add_ctlmsg2(NET_F_ALIVE);
 }
 
 static int ftfw_init(void)
@@ -491,7 +516,14 @@ static int tx_queue_xmit(void *data1, const void *data2)
 {
 	struct nethdr *net = data1;
 
-	nethdr_set_ack(net);
+	if (IS_ACK(net) || IS_NACK(net) || IS_RESYNC(net)) {
+		nethdr_set_ack(net);
+	} else if (IS_ALIVE(net)) {
+		nethdr_set_ctl(net);
+	} else {
+		dlog(LOG_ERR, "sending unknown control message?");
+		return 0;
+	}
 	HDR_HOST2NETWORK(net);
 
 	dp("tx_queue sq: %u fl:%u len:%u\n",
diff --git a/src/sync-mode.c b/src/sync-mode.c
index d5355a7..b2b78ad 100644
--- a/src/sync-mode.c
+++ b/src/sync-mode.c
@@ -131,7 +131,7 @@ static void mcast_handler(void)
 			break;
 		}
 
-		if (IS_CTL(net)) {
+		if (IS_ACK(net) || IS_NACK(net) || IS_RESYNC(net)) {
 			if (remain < NETHDR_ACK_SIZ) {
 				STATE(malformed)++;
 				dlog(LOG_WARNING, "no room for ctl message");