icmp: Store ping socket information in flow table

Currently icmp_id_map[][] stores information about ping sockets in a
bespoke structure.  Move the same information into new types of flow
in the flow table.  To match that change, replace the existing ICMP
timer with a flow-based timer for expiring ping sockets.  This has the
advantage that we only need to scan the active flows, not all possible
ids.

We convert icmp_id_map[][] to point to the flow table entries, rather
than containing its own information.  We do still use that array for
locating the right ping flows, rather than using a "flow native" form
of lookup for the time being.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
[sbrivio: Update id_sock description in comment to icmp_ping_new()]
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/flow.c b/flow.c
index 5bb24cc..80dd269 100644
--- a/flow.c
+++ b/flow.c
@@ -22,6 +22,8 @@ const char *flow_type_str[] = {
 	[FLOW_TYPE_NONE]	= "<none>",
 	[FLOW_TCP]		= "TCP connection",
 	[FLOW_TCP_SPLICE]	= "TCP connection (spliced)",
+	[FLOW_PING4]		= "ICMP ping sequence",
+	[FLOW_PING6]		= "ICMPv6 ping sequence",
 };
 static_assert(ARRAY_SIZE(flow_type_str) == FLOW_NUM_TYPES,
 	      "flow_type_str[] doesn't match enum flow_type");
@@ -29,6 +31,8 @@ static_assert(ARRAY_SIZE(flow_type_str) == FLOW_NUM_TYPES,
 const uint8_t flow_proto[] = {
 	[FLOW_TCP]		= IPPROTO_TCP,
 	[FLOW_TCP_SPLICE]	= IPPROTO_TCP,
+	[FLOW_PING4]		= IPPROTO_ICMP,
+	[FLOW_PING6]		= IPPROTO_ICMPV6,
 };
 static_assert(ARRAY_SIZE(flow_proto) == FLOW_NUM_TYPES,
 	      "flow_proto[] doesn't match enum flow_type");
@@ -295,6 +299,11 @@ void flow_defer_handler(const struct ctx *c, const struct timespec *now)
 			if (!closed && timer)
 				tcp_splice_timer(c, flow);
 			break;
+		case FLOW_PING4:
+		case FLOW_PING6:
+			if (timer)
+				closed = icmp_ping_timer(c, flow, now);
+			break;
 		default:
 			/* Assume other flow types don't need any handling */
 			;