epoll: Generalize epoll_ref to cover things other than sockets

The epoll_ref type includes fields for the IP protocol of a socket, and the
socket fd.  However, we already have a few things in the epoll which aren't
protocol sockets, and we may have more in future.  Rename these fields to
an abstract "fd type" and file descriptor for more generality.

Similarly, rather than using existing IP protocol numbers for the type,
introduce our own number space.  For now these just correspond to the
supported protocols, but we'll expand on that in future.

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

1 files changed, 11 insertions, 11 deletions

diff --git a/tcp.c b/tcp.c
index d9ecee5..18b781a 100644
--- a/tcp.c
+++ b/tcp.c
@@ -643,7 +643,7 @@ static void conn_flag_do(const struct ctx *c, struct tcp_tap_conn *conn,
 static int tcp_epoll_ctl(const struct ctx *c, struct tcp_tap_conn *conn)
 {
 	int m = conn->c.in_epoll ? EPOLL_CTL_MOD : EPOLL_CTL_ADD;
-	union epoll_ref ref = { .proto = IPPROTO_TCP, .s = conn->sock,
+	union epoll_ref ref = { .type = EPOLL_TYPE_TCP, .fd = conn->sock,
 				.tcp.index = CONN_IDX(conn) };
 	struct epoll_event ev = { .data.u64 = ref.u64 };
 
@@ -663,8 +663,8 @@ static int tcp_epoll_ctl(const struct ctx *c, struct tcp_tap_conn *conn)
 	conn->c.in_epoll = true;
 
 	if (conn->timer != -1) {
-		union epoll_ref ref_t = { .proto = IPPROTO_TCP,
-					  .s = conn->sock,
+		union epoll_ref ref_t = { .type = EPOLL_TYPE_TCP,
+					  .fd = conn->sock,
 					  .tcp.timer = 1,
 					  .tcp.index = CONN_IDX(conn) };
 		struct epoll_event ev_t = { .data.u64 = ref_t.u64,
@@ -692,8 +692,8 @@ static void tcp_timer_ctl(const struct ctx *c, struct tcp_tap_conn *conn)
 		return;
 
 	if (conn->timer == -1) {
-		union epoll_ref ref = { .proto = IPPROTO_TCP,
-					.s = conn->sock,
+		union epoll_ref ref = { .type = EPOLL_TYPE_TCP,
+					.fd = conn->sock,
 					.tcp.timer = 1,
 					.tcp.index = CONN_IDX(conn) };
 		struct epoll_event ev = { .data.u64 = ref.u64,
@@ -701,7 +701,7 @@ static void tcp_timer_ctl(const struct ctx *c, struct tcp_tap_conn *conn)
 		int fd;
 
 		fd = timerfd_create(CLOCK_MONOTONIC, 0);
-		if (fd == -1 || fd > SOCKET_MAX) {
+		if (fd == -1 || fd > FD_REF_MAX) {
 			debug("TCP: failed to get timer: %s", strerror(errno));
 			if (fd > -1)
 				close(fd);
@@ -1908,7 +1908,7 @@ int tcp_conn_new_sock(const struct ctx *c, sa_family_t af)
 
 	s = socket(af, SOCK_STREAM | SOCK_NONBLOCK, IPPROTO_TCP);
 
-	if (s > SOCKET_MAX) {
+	if (s > FD_REF_MAX) {
 		close(s);
 		return -EIO;
 	}
@@ -2791,7 +2791,7 @@ static void tcp_conn_from_sock(struct ctx *c, union epoll_ref ref,
 	 * https://github.com/llvm/llvm-project/issues/58992
 	 */
 	memset(&sa, 0, sizeof(struct sockaddr_in6));
-	s = accept4(ref.s, (struct sockaddr *)&sa, &sl, SOCK_NONBLOCK);
+	s = accept4(ref.fd, (struct sockaddr *)&sa, &sl, SOCK_NONBLOCK);
 	if (s < 0)
 		return;
 
@@ -2948,7 +2948,7 @@ void tcp_sock_handler(struct ctx *c, union epoll_ref ref, uint32_t events,
 	conn = tc + ref.tcp.index;
 
 	if (conn->c.spliced)
-		tcp_splice_sock_handler(c, &conn->splice, ref.s, events);
+		tcp_splice_sock_handler(c, &conn->splice, ref.fd, events);
 	else
 		tcp_tap_sock_handler(c, &conn->tap, events);
 }
@@ -2999,7 +2999,7 @@ static int tcp_sock_init_af(const struct ctx *c, int af, in_port_t port,
 int tcp_sock_init(const struct ctx *c, sa_family_t af, const void *addr,
 		  const char *ifname, in_port_t port)
 {
-	int r4 = SOCKET_MAX + 1, r6 = SOCKET_MAX + 1;
+	int r4 = FD_REF_MAX + 1, r6 = FD_REF_MAX + 1;
 
 	if (af == AF_UNSPEC && c->ifi4 && c->ifi6)
 		/* Attempt to get a dual stack socket */
@@ -3013,7 +3013,7 @@ int tcp_sock_init(const struct ctx *c, sa_family_t af, const void *addr,
 	if ((af == AF_INET6 || af == AF_UNSPEC) && c->ifi6)
 		r6 = tcp_sock_init_af(c, AF_INET6, port, addr, ifname);
 
-	if (IN_INTERVAL(0, SOCKET_MAX, r4) || IN_INTERVAL(0, SOCKET_MAX, r6))
+	if (IN_INTERVAL(0, FD_REF_MAX, r4) || IN_INTERVAL(0, FD_REF_MAX, r6))
 		return 0;
 
 	return r4 < 0 ? r4 : r6;