tcp, flow: Remove redundant information, repack connection structures

Some information we explicitly store in the TCP connection is now
duplicated in the common flow structure.  Access it from there instead, and
remove it from the TCP specific structure.   With that done we can reorder
both the "tap" and "splice" TCP structures a bit to get better packing for
the new combined flow table entries.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

1 files changed, 27 insertions, 25 deletions

diff --git a/tcp.c b/tcp.c
index 914a074..3d3df4c 100644
--- a/tcp.c
+++ b/tcp.c
@@ -333,8 +333,6 @@
 
 #define ACK_IF_NEEDED	0		/* See tcp_send_flag() */
 
-#define TAPSIDE(conn_)	((conn_)->f.pif[1] == PIF_TAP)
-
 #define CONN_IS_CLOSING(conn)						\
 	(((conn)->events & ESTABLISHED) &&				\
 	 ((conn)->events & (SOCK_FIN_RCVD | TAP_FIN_RCVD)))
@@ -673,10 +671,11 @@ void conn_event_do(const struct ctx *c, struct tcp_tap_conn *conn,
  */
 static int tcp_rtt_dst_low(const struct tcp_tap_conn *conn)
 {
+	const struct flowside *tapside = TAPFLOW(conn);
 	int i;
 
 	for (i = 0; i < LOW_RTT_TABLE_SIZE; i++)
-		if (inany_equals(&conn->faddr, low_rtt_dst + i))
+		if (inany_equals(&tapside->faddr, low_rtt_dst + i))
 			return 1;
 
 	return 0;
@@ -691,6 +690,7 @@ static void tcp_rtt_dst_check(const struct tcp_tap_conn *conn,
 			      const struct tcp_info *tinfo)
 {
 #ifdef HAS_MIN_RTT
+	const struct flowside *tapside = TAPFLOW(conn);
 	int i, hole = -1;
 
 	if (!tinfo->tcpi_min_rtt ||
@@ -698,7 +698,7 @@ static void tcp_rtt_dst_check(const struct tcp_tap_conn *conn,
 		return;
 
 	for (i = 0; i < LOW_RTT_TABLE_SIZE; i++) {
-		if (inany_equals(&conn->faddr, low_rtt_dst + i))
+		if (inany_equals(&tapside->faddr, low_rtt_dst + i))
 			return;
 		if (hole == -1 && IN6_IS_ADDR_UNSPECIFIED(low_rtt_dst + i))
 			hole = i;
@@ -710,7 +710,7 @@ static void tcp_rtt_dst_check(const struct tcp_tap_conn *conn,
 	if (hole == -1)
 		return;
 
-	low_rtt_dst[hole++] = conn->faddr;
+	low_rtt_dst[hole++] = tapside->faddr;
 	if (hole == LOW_RTT_TABLE_SIZE)
 		hole = 0;
 	inany_from_af(low_rtt_dst + hole, AF_INET6, &in6addr_any);
@@ -865,8 +865,10 @@ static int tcp_hash_match(const struct tcp_tap_conn *conn,
 			  const union inany_addr *faddr,
 			  in_port_t eport, in_port_t fport)
 {
-	if (inany_equals(&conn->faddr, faddr) &&
-	    conn->eport == eport && conn->fport == fport)
+	const struct flowside *tapside = TAPFLOW(conn);
+
+	if (inany_equals(&tapside->faddr, faddr) &&
+	    tapside->eport == eport && tapside->fport == fport)
 		return 1;
 
 	return 0;
@@ -900,7 +902,10 @@ static uint64_t tcp_hash(const struct ctx *c, const union inany_addr *faddr,
 static uint64_t tcp_conn_hash(const struct ctx *c,
 			      const struct tcp_tap_conn *conn)
 {
-	return tcp_hash(c, &conn->faddr, conn->eport, conn->fport);
+	const struct flowside *tapside = TAPFLOW(conn);
+
+	return tcp_hash(c, &tapside->faddr, tapside->eport,
+			tapside->fport);
 }
 
 /**
@@ -1035,10 +1040,12 @@ void tcp_defer_handler(struct ctx *c)
  * @seq:	Sequence number
  */
 static void tcp_fill_header(struct tcphdr *th,
-			       const struct tcp_tap_conn *conn, uint32_t seq)
+			    const struct tcp_tap_conn *conn, uint32_t seq)
 {
-	th->source = htons(conn->fport);
-	th->dest = htons(conn->eport);
+	const struct flowside *tapside = TAPFLOW(conn);
+
+	th->source = htons(tapside->fport);
+	th->dest = htons(tapside->eport);
 	th->seq = htonl(seq);
 	th->ack_seq = htonl(conn->seq_ack_to_tap);
 	if (conn->events & ESTABLISHED)	{
@@ -1070,7 +1077,8 @@ static size_t tcp_fill_headers4(const struct ctx *c,
 				size_t dlen, const uint16_t *check,
 				uint32_t seq)
 {
-	const struct in_addr *a4 = inany_v4(&conn->faddr);
+	const struct flowside *tapside = TAPFLOW(conn);
+	const struct in_addr *a4 = inany_v4(&tapside->faddr);
 	size_t l4len = dlen + sizeof(*th);
 	size_t l3len = l4len + sizeof(*iph);
 
@@ -1112,10 +1120,11 @@ static size_t tcp_fill_headers6(const struct ctx *c,
 				struct ipv6hdr *ip6h, struct tcphdr *th,
 				size_t dlen, uint32_t seq)
 {
+	const struct flowside *tapside = TAPFLOW(conn);
 	size_t l4len = dlen + sizeof(*th);
 
 	ip6h->payload_len = htons(l4len);
-	ip6h->saddr = conn->faddr.a6;
+	ip6h->saddr = tapside->faddr.a6;
 	if (IN6_IS_ADDR_LINKLOCAL(&ip6h->saddr))
 		ip6h->daddr = c->ip6.addr_ll_seen;
 	else
@@ -1154,7 +1163,8 @@ size_t tcp_l2_buf_fill_headers(const struct ctx *c,
 			       struct iovec *iov, size_t dlen,
 			       const uint16_t *check, uint32_t seq)
 {
-	const struct in_addr *a4 = inany_v4(&conn->faddr);
+	const struct flowside *tapside = TAPFLOW(conn);
+	const struct in_addr *a4 = inany_v4(&tapside->faddr);
 
 	if (a4) {
 		return tcp_fill_headers4(c, conn, iov[TCP_IOV_TAP].iov_base,
@@ -1465,6 +1475,7 @@ static void tcp_seq_init(const struct ctx *c, struct tcp_tap_conn *conn,
 			 const struct timespec *now)
 {
 	struct siphash_state state = SIPHASH_INIT(c->hash_secret);
+	const struct flowside *tapside = TAPFLOW(conn);
 	union inany_addr aany;
 	uint64_t hash;
 	uint32_t ns;
@@ -1474,10 +1485,10 @@ static void tcp_seq_init(const struct ctx *c, struct tcp_tap_conn *conn,
 	else
 		inany_from_af(&aany, AF_INET6, &c->ip6.addr);
 
-	inany_siphash_feed(&state, &conn->faddr);
+	inany_siphash_feed(&state, &tapside->faddr);
 	inany_siphash_feed(&state, &aany);
 	hash = siphash_final(&state, 36,
-			     (uint64_t)conn->fport << 16 | conn->eport);
+			     (uint64_t)tapside->fport << 16 | tapside->eport);
 
 	/* 32ns ticks, overflows 32 bits every 137s */
 	ns = (now->tv_sec * 1000000000 + now->tv_nsec) >> 5;
@@ -1766,11 +1777,6 @@ static void tcp_conn_from_tap(struct ctx *c, sa_family_t af,
 	if (!(conn->wnd_from_tap = (htons(th->window) >> conn->ws_from_tap)))
 		conn->wnd_from_tap = 1;
 
-	inany_from_af(&conn->faddr, af, daddr);
-
-	conn->fport = dstport;
-	conn->eport = srcport;
-
 	conn->seq_init_from_tap = ntohl(th->seq);
 	conn->seq_from_tap = conn->seq_init_from_tap + 1;
 	conn->seq_ack_to_tap = conn->seq_from_tap;
@@ -2314,10 +2320,6 @@ static void tcp_tap_conn_from_sock(struct ctx *c, in_port_t dstport,
 	conn->ws_to_tap = conn->ws_from_tap = 0;
 	conn_event(c, conn, SOCK_ACCEPTED);
 
-	conn->faddr = saddr;
-	conn->fport = srcport;
-	conn->eport = dstport;
-
 	tcp_seq_init(c, conn, now);
 	tcp_hash_insert(c, conn);