pif: Record originating pif in listening socket refs

For certain socket types, we record in the epoll ref whether they're
sockets in the namespace, or on the host.  We now have the notion of "pif"
to indicate what "place" a socket is associated with, so generalise the
simple one-bit 'ns' to a pif id.

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

1 files changed, 12 insertions, 11 deletions

diff --git a/udp.c b/udp.c
index db35859..ccfe2fa 100644
--- a/udp.c
+++ b/udp.c
@@ -365,7 +365,7 @@ static void udp_sock6_iov_init(const struct ctx *c)
  * @c:		Execution context
  * @v6:		Set for IPv6 sockets
  * @src:	Source port of original connection, host order
- * @splice:	UDP_BACK_TO_INIT from init, UDP_BACK_TO_NS from namespace
+ * @ns:		Does the splice originate in the ns or not
  *
  * Return: prepared socket, negative error code on failure
  *
@@ -375,16 +375,17 @@ 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 = { .type = EPOLL_TYPE_UDP,
-				.udp = { .splice = true, .ns = ns,
-					 .v6 = v6, .port = src }
+				.udp = { .splice = true, .v6 = v6, .port = src }
 			      };
 	struct udp_splice_port *sp;
 	int act, s;
 
 	if (ns) {
+		ref.udp.pif = PIF_SPLICE;
 		sp = &udp_splice_ns[v6 ? V6 : V4][src];
 		act = UDP_ACT_SPLICE_NS;
 	} else {
+		ref.udp.pif = PIF_HOST;
 		sp = &udp_splice_init[v6 ? V6 : V4][src];
 		act = UDP_ACT_SPLICE_INIT;
 	}
@@ -495,15 +496,15 @@ static int udp_mmh_splice_port(bool v6, const struct mmsghdr *mmh)
  * @n:		Number of datagrams to send
  * @src:	Datagrams will be sent from this port (on origin side)
  * @dst:	Datagrams will be send to this port (on destination side)
+ * @from_pif:	pif from which the packet originated
  * @v6:		Send as IPv6?
- * @from_ns:	If true send from pasta ns to init, otherwise reverse
  * @allow_new:	If true create sending socket if needed, if false discard
  *              if no sending socket is available
  * @now:	Timestamp
  */
 static void udp_splice_sendfrom(const struct ctx *c, unsigned start, unsigned n,
-				in_port_t src, in_port_t dst,
-				bool v6, bool from_ns, bool allow_new,
+				in_port_t src, in_port_t dst, uint8_t from_pif,
+				bool v6, bool allow_new,
 				const struct timespec *now)
 {
 	struct mmsghdr *mmh_recv, *mmh_send;
@@ -518,7 +519,7 @@ static void udp_splice_sendfrom(const struct ctx *c, unsigned start, unsigned n,
 		mmh_send = udp4_mh_splice;
 	}
 
-	if (from_ns) {
+	if (from_pif == PIF_SPLICE) {
 		src += c->udp.fwd_in.rdelta[src];
 		s = udp_splice_init[v6][src].sock;
 		if (!s && allow_new)
@@ -530,6 +531,7 @@ static void udp_splice_sendfrom(const struct ctx *c, unsigned start, unsigned n,
 		udp_splice_ns[v6][dst].ts = now->tv_sec;
 		udp_splice_init[v6][src].ts = now->tv_sec;
 	} else {
+		ASSERT(from_pif == PIF_HOST);
 		src += c->udp.fwd_out.rdelta[src];
 		s = udp_splice_ns[v6][src].sock;
 		if (!s && allow_new) {
@@ -776,7 +778,7 @@ void udp_sock_handler(const struct ctx *c, union epoll_ref ref, uint32_t events,
 
 		if (splicefrom >= 0)
 			udp_splice_sendfrom(c, i, m, splicefrom, dstport,
-					    v6, ref.udp.ns, ref.udp.orig, now);
+					    ref.udp.pif, v6, ref.udp.orig, now);
 		else
 			udp_tap_send(c, i, m, dstport, v6, now);
 	}
@@ -974,8 +976,10 @@ int udp_sock_init(const struct ctx *c, int ns, sa_family_t af,
 	int s, r4 = FD_REF_MAX + 1, r6 = FD_REF_MAX + 1;
 
 	if (ns) {
+		uref.pif = PIF_SPLICE;
 		uref.port = (in_port_t)(port + c->udp.fwd_out.f.delta[port]);
 	} else {
+		uref.pif = PIF_HOST;
 		uref.port = (in_port_t)(port + c->udp.fwd_in.f.delta[port]);
 	}
 
@@ -990,7 +994,6 @@ int udp_sock_init(const struct ctx *c, int ns, sa_family_t af,
 			udp_splice_init[V4][port].sock = s < 0 ? -1 : s;
 		} else {
 			struct in_addr loopback = { htonl(INADDR_LOOPBACK) };
-			uref.ns = true;
 
 			r4 = s = sock_l4(c, AF_INET, IPPROTO_UDP, &loopback,
 					 ifname, port, uref.u32);
@@ -1008,8 +1011,6 @@ int udp_sock_init(const struct ctx *c, int ns, sa_family_t af,
 			udp_tap_map[V6][uref.port].sock = s < 0 ? -1 : s;
 			udp_splice_init[V6][port].sock = s < 0 ? -1 : s;
 		} else {
-			uref.ns = true;
-
 			r6 = s = sock_l4(c, AF_INET6, IPPROTO_UDP,
 					 &in6addr_loopback,
 					 ifname, port, uref.u32);