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, 20 insertions, 7 deletions

diff --git a/util.c b/util.c
index 019c56c..2cac7ba 100644
--- a/util.c
+++ b/util.c
@@ -102,7 +102,7 @@ int sock_l4(const struct ctx *c, int af, uint8_t proto,
 	    const void *bind_addr, const char *ifname, uint16_t port,
 	    uint32_t data)
 {
-	union epoll_ref ref = { .proto = proto, .data = data };
+	union epoll_ref ref = { .data = data };
 	struct sockaddr_in addr4 = {
 		.sin_family = AF_INET,
 		.sin_port = htons(port),
@@ -118,9 +118,22 @@ int sock_l4(const struct ctx *c, int af, uint8_t proto,
 	int fd, sl, y = 1, ret;
 	struct epoll_event ev;
 
-	if (proto != IPPROTO_TCP && proto != IPPROTO_UDP &&
-	    proto != IPPROTO_ICMP && proto != IPPROTO_ICMPV6)
+	switch (proto) {
+	case IPPROTO_TCP:
+		ref.type = EPOLL_TYPE_TCP;
+		break;
+	case IPPROTO_UDP:
+		ref.type = EPOLL_TYPE_UDP;
+		break;
+	case IPPROTO_ICMP:
+		ref.type = EPOLL_TYPE_ICMP;
+		break;
+	case IPPROTO_ICMPV6:
+		ref.type = EPOLL_TYPE_ICMPV6;
+		break;
+	default:
 		return -EPFNOSUPPORT;	/* Not implemented. */
+	}
 
 	if (af == AF_UNSPEC) {
 		if (!DUAL_STACK_SOCKETS || bind_addr)
@@ -140,12 +153,12 @@ int sock_l4(const struct ctx *c, int af, uint8_t proto,
 		return ret;
 	}
 
-	if (fd > SOCKET_MAX) {
+	if (fd > FD_REF_MAX) {
 		close(fd);
 		return -EBADF;
 	}
 
-	ref.s = fd;
+	ref.fd = fd;
 
 	if (af == AF_INET) {
 		if (bind_addr)
@@ -188,8 +201,8 @@ int sock_l4(const struct ctx *c, int af, uint8_t proto,
 		if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE,
 			       ifname, strlen(ifname))) {
 			ret = -errno;
-			warn("Can't bind socket for %s port %u to %s, closing",
-			     ip_proto_str[proto], port, ifname);
+			warn("Can't bind %s socket for port %u to %s, closing",
+			     EPOLL_TYPE_STR(proto), port, ifname);
 			close(fd);
 			return ret;
 		}