Use C11 anonymous members to make poll refs less verbose to use

union epoll_ref has a deeply nested set of structs and unions to let us
subdivide it into the various different fields we want.  This means that
referencing elements can involve an awkward long string of intermediate
fields.

Using C11 anonymous structs and unions lets us do this less clumsily.

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

1 files changed, 23 insertions, 27 deletions

diff --git a/udp.c b/udp.c
index 39c59d4..f749f5f 100644
--- a/udp.c
+++ b/udp.c
@@ -388,9 +388,9 @@ static void udp_sock6_iov_init(const struct ctx *c)
 int udp_splice_new(const struct ctx *c, int v6, in_port_t src, bool ns)
 {
 	struct epoll_event ev = { .events = EPOLLIN | EPOLLRDHUP | EPOLLHUP };
-	union epoll_ref ref = { .r.proto = IPPROTO_UDP,
-				.r.p.udp.udp = { .splice = true, .ns = ns,
-						 .v6 = v6, .port = src }
+	union epoll_ref ref = { .proto = IPPROTO_UDP,
+				.udp = { .splice = true, .ns = ns,
+					     .v6 = v6, .port = src }
 			      };
 	struct udp_splice_port *sp;
 	int act, s;
@@ -414,7 +414,7 @@ int udp_splice_new(const struct ctx *c, int v6, in_port_t src, bool ns)
 	if (s < 0)
 		return s;
 
-	ref.r.s = s;
+	ref.s = s;
 
 	if (v6) {
 		struct sockaddr_in6 addr6 = {
@@ -752,8 +752,8 @@ void udp_sock_handler(struct ctx *c, union epoll_ref ref, uint32_t events,
 	 * for pasta mode.
 	 */
 	ssize_t n = (c->mode == MODE_PASST ? UDP_MAX_FRAMES : 1);
-	in_port_t dstport = ref.r.p.udp.udp.port;
-	bool v6 = ref.r.p.udp.udp.v6;
+	in_port_t dstport = ref.udp.port;
+	bool v6 = ref.udp.v6;
 	struct mmsghdr *mmh_recv;
 	int i, m;
 
@@ -768,7 +768,7 @@ void udp_sock_handler(struct ctx *c, union epoll_ref ref, uint32_t events,
 		udp4_localname.sin_port = htons(dstport);
 	}
 
-	n = recvmmsg(ref.r.s, mmh_recv, n, 0, NULL);
+	n = recvmmsg(ref.s, mmh_recv, n, 0, NULL);
 	if (n <= 0)
 		return;
 
@@ -776,7 +776,7 @@ void udp_sock_handler(struct ctx *c, union epoll_ref ref, uint32_t events,
 		int splicefrom = -1;
 		m = n;
 
-		if (ref.r.p.udp.udp.splice) {
+		if (ref.udp.splice) {
 			splicefrom = udp_mmh_splice_port(v6, mmh_recv + i);
 
 			for (m = 1; i + m < n; m++) {
@@ -790,8 +790,7 @@ void udp_sock_handler(struct ctx *c, union epoll_ref ref, uint32_t events,
 
 		if (splicefrom >= 0)
 			udp_splice_sendfrom(c, i, m, splicefrom, dstport,
-					    v6, ref.r.p.udp.udp.ns,
-					    ref.r.p.udp.udp.orig, now);
+					    v6, ref.udp.ns, ref.udp.orig, now);
 		else
 			udp_tap_send(c, i, m, dstport, v6, now);
 	}
@@ -857,7 +856,7 @@ int udp_tap_handler(struct ctx *c, int af, const void *addr,
 		}
 
 		if (!(s = udp_tap_map[V4][src].sock)) {
-			union udp_epoll_ref uref = { .udp.port = src };
+			union udp_epoll_ref uref = { .port = src };
 			in_addr_t bind_addr = { 0 };
 			const char *bind_if = NULL;
 
@@ -907,8 +906,7 @@ int udp_tap_handler(struct ctx *c, int af, const void *addr,
 		}
 
 		if (!(s = udp_tap_map[V6][src].sock)) {
-			union udp_epoll_ref uref = { .udp.v6 = 1,
-						     .udp.port = src };
+			union udp_epoll_ref uref = { .v6 = 1, .port = src };
 			const char *bind_if = NULL;
 
 			if (!IN6_IS_ADDR_LOOPBACK(&s_in6.sin6_addr) &&
@@ -986,27 +984,25 @@ int udp_sock_init(const struct ctx *c, int ns, sa_family_t af,
 	int s, r4 = SOCKET_MAX + 1, r6 = SOCKET_MAX + 1;
 
 	if (ns) {
-		uref.udp.port = (in_port_t)(port +
-					    c->udp.fwd_out.f.delta[port]);
+		uref.port = (in_port_t)(port + c->udp.fwd_out.f.delta[port]);
 	} else {
-		uref.udp.port = (in_port_t)(port +
-					    c->udp.fwd_in.f.delta[port]);
+		uref.port = (in_port_t)(port + c->udp.fwd_in.f.delta[port]);
 	}
 
 	if ((af == AF_INET || af == AF_UNSPEC) && c->ifi4) {
-		uref.udp.v6 = 0;
-		uref.udp.splice = (c->mode == MODE_PASTA);
-		uref.udp.orig = true;
+		uref.v6 = 0;
+		uref.splice = (c->mode == MODE_PASTA);
+		uref.orig = true;
 
 		if (!ns) {
 			r4 = s = sock_l4(c, AF_INET, IPPROTO_UDP, addr,
 					 ifname, port, uref.u32);
 
-			udp_tap_map[V4][uref.udp.port].sock = s < 0 ? -1 : s;
+			udp_tap_map[V4][uref.port].sock = s < 0 ? -1 : s;
 			udp_splice_init[V4][port].sock = s < 0 ? -1 : s;
 		} else {
 			struct in_addr loopback = { htonl(INADDR_LOOPBACK) };
-			uref.udp.ns = true;
+			uref.ns = true;
 
 			r4 = s = sock_l4(c, AF_INET, IPPROTO_UDP, &loopback,
 					 ifname, port, uref.u32);
@@ -1015,18 +1011,18 @@ int udp_sock_init(const struct ctx *c, int ns, sa_family_t af,
 	}
 
 	if ((af == AF_INET6 || af == AF_UNSPEC) && c->ifi6) {
-		uref.udp.v6 = 1;
-		uref.udp.splice = (c->mode == MODE_PASTA);
-		uref.udp.orig = true;
+		uref.v6 = 1;
+		uref.splice = (c->mode == MODE_PASTA);
+		uref.orig = true;
 
 		if (!ns) {
 			r6 = s = sock_l4(c, AF_INET6, IPPROTO_UDP, addr,
 					 ifname, port, uref.u32);
 
-			udp_tap_map[V6][uref.udp.port].sock = s < 0 ? -1 : s;
+			udp_tap_map[V6][uref.port].sock = s < 0 ? -1 : s;
 			udp_splice_init[V6][port].sock = s < 0 ? -1 : s;
 		} else {
-			uref.udp.ns = true;
+			uref.ns = true;
 
 			r6 = s = sock_l4(c, AF_INET6, IPPROTO_UDP,
 					 &in6addr_loopback,