tap: Pass source address to protocol handler functions

The tap code passes the IPv4 or IPv6 destination address of packets it
receives to the protocol specific code.  Currently that protocol code
doesn't use the source address, but we want it to in future.  So, in
preparation, pass the IPv4/IPv6 source address of tap packets to those
functions as well.

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

1 files changed, 17 insertions, 11 deletions

diff --git a/tcp.c b/tcp.c
index 0322842..68141e9 100644
--- a/tcp.c
+++ b/tcp.c
@@ -2005,13 +2005,15 @@ static void tcp_bind_outbound(const struct ctx *c, int s, sa_family_t af)
  * tcp_conn_from_tap() - Handle connection request (SYN segment) from tap
  * @c:		Execution context
  * @af:		Address family, AF_INET or AF_INET6
- * @addr:	Remote address, pointer to in_addr or in6_addr
+ * @saddr:	Source address, pointer to in_addr or in6_addr
+ * @daddr:	Destination address, pointer to in_addr or in6_addr
  * @th:		TCP header from tap: caller MUST ensure it's there
  * @opts:	Pointer to start of options
  * @optlen:	Bytes in options: caller MUST ensure available length
  * @now:	Current timestamp
  */
-static void tcp_conn_from_tap(struct ctx *c, int af, const void *addr,
+static void tcp_conn_from_tap(struct ctx *c,
+			      int af, const void *saddr, const void *daddr,
 			      const struct tcphdr *th, const char *opts,
 			      size_t optlen, const struct timespec *now)
 {
@@ -2019,18 +2021,20 @@ static void tcp_conn_from_tap(struct ctx *c, int af, const void *addr,
 	struct sockaddr_in addr4 = {
 		.sin_family = AF_INET,
 		.sin_port = th->dest,
-		.sin_addr = *(struct in_addr *)addr,
+		.sin_addr = *(struct in_addr *)daddr,
 	};
 	struct sockaddr_in6 addr6 = {
 		.sin6_family = AF_INET6,
 		.sin6_port = th->dest,
-		.sin6_addr = *(struct in6_addr *)addr,
+		.sin6_addr = *(struct in6_addr *)daddr,
 	};
 	const struct sockaddr *sa;
 	struct tcp_tap_conn *conn;
 	socklen_t sl;
 	int s, mss;
 
+	(void)saddr;
+
 	if (c->tcp.conn_count >= TCP_MAX_CONNS)
 		return;
 
@@ -2039,9 +2043,9 @@ static void tcp_conn_from_tap(struct ctx *c, int af, const void *addr,
 			return;
 
 	if (!c->no_map_gw) {
-		if (af == AF_INET && IN4_ARE_ADDR_EQUAL(addr, &c->ip4.gw))
+		if (af == AF_INET && IN4_ARE_ADDR_EQUAL(daddr, &c->ip4.gw))
 			addr4.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
-		if (af == AF_INET6 && IN6_ARE_ADDR_EQUAL(addr, &c->ip6.gw))
+		if (af == AF_INET6 && IN6_ARE_ADDR_EQUAL(daddr, &c->ip6.gw))
 			addr6.sin6_addr	= in6addr_loopback;
 	}
 
@@ -2078,7 +2082,7 @@ static void tcp_conn_from_tap(struct ctx *c, int af, const void *addr,
 	if (!(conn->wnd_from_tap = (htons(th->window) >> conn->ws_from_tap)))
 		conn->wnd_from_tap = 1;
 
-	inany_from_af(&conn->addr, af, addr);
+	inany_from_af(&conn->addr, af, daddr);
 
 	if (af == AF_INET) {
 		sa = (struct sockaddr *)&addr4;
@@ -2556,13 +2560,14 @@ static void tcp_conn_from_sock_finish(struct ctx *c, struct tcp_tap_conn *conn,
  * tcp_tap_handler() - Handle packets from tap and state transitions
  * @c:		Execution context
  * @af:		Address family, AF_INET or AF_INET6
- * @addr:	Destination address
+ * @saddr:	Source address
+ * @daddr:	Destination address
  * @p:		Pool of TCP packets, with TCP headers
  * @now:	Current timestamp
  *
  * Return: count of consumed packets
  */
-int tcp_tap_handler(struct ctx *c, int af, const void *addr,
+int tcp_tap_handler(struct ctx *c, int af, const void *saddr, const void *daddr,
 		    const struct pool *p, const struct timespec *now)
 {
 	struct tcp_tap_conn *conn;
@@ -2583,12 +2588,13 @@ int tcp_tap_handler(struct ctx *c, int af, const void *addr,
 	optlen = MIN(optlen, ((1UL << 4) /* from doff width */ - 6) * 4UL);
 	opts = packet_get(p, 0, sizeof(*th), optlen, NULL);
 
-	conn = tcp_hash_lookup(c, af, addr, htons(th->source), htons(th->dest));
+	conn = tcp_hash_lookup(c, af, daddr, htons(th->source), htons(th->dest));
 
 	/* New connection from tap */
 	if (!conn) {
 		if (opts && th->syn && !th->ack)
-			tcp_conn_from_tap(c, af, addr, th, opts, optlen, now);
+			tcp_conn_from_tap(c, af, saddr, daddr, th,
+					  opts, optlen, now);
 		return 1;
 	}