[PATCH v2 3/3] tcp: Simplify handling of getsockname()

[David Gibson <david@gibson.dropbear.id.au>]

For migration we need to get the specific local address and port for
connected sockets with getsockname().  We currently open code marshalling
the results into the flow entry.

However, we already have inany_from_sockaddr() which handles the fiddly
parts of this, so use it.  Also report failures, which may make debugging
problems easier.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 tcp.c | 24 +++++++-----------------
 1 file changed, 7 insertions(+), 17 deletions(-)

diff --git a/tcp.c b/tcp.c
index 7ce0f4cb..dbdaa9d9 100644
--- a/tcp.c
+++ b/tcp.c
@@ -1712,24 +1712,14 @@ static void tcp_conn_from_tap(const struct ctx *c, sa_family_t af,
 	tcp_epoll_ctl(c, conn);
 
 	if (c->mode == MODE_VU) { /* To rebind to same oport after migration */
-		if (af == AF_INET) {
-			struct sockaddr_in s_in;
-
-			sl = sizeof(s_in);
-			if (!getsockname(s, (struct sockaddr *)&s_in, &sl)) {
-				/* NOLINTNEXTLINE(clang-analyzer-core.CallAndMessage) */
-				tgt->oport = ntohs(s_in.sin_port);
-				tgt->oaddr = inany_from_v4(s_in.sin_addr);
-			}
-		} else {
-			struct sockaddr_in6 s_in6;
+		union sockaddr_inany sa;
+		socklen_t sl = sizeof(sa);
 
-			sl = sizeof(s_in6);
-			if (!getsockname(s, (struct sockaddr *)&s_in6, &sl)) {
-				/* NOLINTNEXTLINE(clang-analyzer-core.CallAndMessage) */
-				tgt->oport = ntohs(s_in6.sin6_port);
-				tgt->oaddr.a6 = s_in6.sin6_addr;
-			}
+		if (!getsockname(s, &sa.sa, &sl)) {
+			inany_from_sockaddr(&tgt->oaddr, &tgt->oport, &sa);
+		} else {
+			err("Failed to get local address for socket: %s",
+			    strerror_(errno));
 		}
 	}
 
-- 
@@ -1712,24 +1712,14 @@ static void tcp_conn_from_tap(const struct ctx *c, sa_family_t af,
 	tcp_epoll_ctl(c, conn);
 
 	if (c->mode == MODE_VU) { /* To rebind to same oport after migration */
-		if (af == AF_INET) {
-			struct sockaddr_in s_in;
-
-			sl = sizeof(s_in);
-			if (!getsockname(s, (struct sockaddr *)&s_in, &sl)) {
-				/* NOLINTNEXTLINE(clang-analyzer-core.CallAndMessage) */
-				tgt->oport = ntohs(s_in.sin_port);
-				tgt->oaddr = inany_from_v4(s_in.sin_addr);
-			}
-		} else {
-			struct sockaddr_in6 s_in6;
+		union sockaddr_inany sa;
+		socklen_t sl = sizeof(sa);
 
-			sl = sizeof(s_in6);
-			if (!getsockname(s, (struct sockaddr *)&s_in6, &sl)) {
-				/* NOLINTNEXTLINE(clang-analyzer-core.CallAndMessage) */
-				tgt->oport = ntohs(s_in6.sin6_port);
-				tgt->oaddr.a6 = s_in6.sin6_addr;
-			}
+		if (!getsockname(s, &sa.sa, &sl)) {
+			inany_from_sockaddr(&tgt->oaddr, &tgt->oport, &sa);
+		} else {
+			err("Failed to get local address for socket: %s",
+			    strerror_(errno));
 		}
 	}
 
-- 
2.48.1