session: do not match listeners when looking for lcl portv25.02-rc2stable/2502

Also optimize lookup to avoid session rules table matching.

Type: fix

Change-Id: I5b62c870edd9f7486e7de1417816fffa30d03a3e
Signed-off-by: Florin Coras <fcoras@cisco.com>
(cherry picked from commit 09341c6bbef28c03c1b026ff78808b000bf7d79d)

3 files changed, 73 insertions, 5 deletions

diff --git a/src/vnet/session/session_lookup.c b/src/vnet/session/session_lookup.c
index 28a1feb1ed8..7678b0e0761 100644
--- a/src/vnet/session/session_lookup.c
+++ b/src/vnet/session/session_lookup.c
@@ -1380,6 +1380,71 @@ session_lookup_connection (u32 fib_index, ip46_address_t * lcl,
 				       lcl_port, rmt_port, proto);
 }
 
+/**
+ * Lookup exact match 6-tuple amongst established and half-open sessions
+ *
+ * Does not look into session rules table and does not try to find a listener.
+ */
+transport_connection_t *
+session_lookup_6tuple (u32 fib_index, ip46_address_t *lcl, ip46_address_t *rmt,
+		       u16 lcl_port, u16 rmt_port, u8 proto, u8 is_ip4)
+{
+  session_table_t *st;
+  session_t *s;
+  int rv;
+
+  if (is_ip4)
+    {
+      session_kv4_t kv4;
+
+      st = session_table_get_for_fib_index (FIB_PROTOCOL_IP4, fib_index);
+      if (PREDICT_FALSE (!st))
+	return 0;
+
+      /*
+       * Lookup session amongst established ones
+       */
+      make_v4_ss_kv (&kv4, &lcl->ip4, &rmt->ip4, lcl_port, rmt_port, proto);
+      rv = clib_bihash_search_inline_16_8 (&st->v4_session_hash, &kv4);
+      if (rv == 0)
+	{
+	  s = session_get_from_handle (kv4.value);
+	  return transport_get_connection (proto, s->connection_index,
+					   s->thread_index);
+	}
+
+      /*
+       * Try half-open connections
+       */
+      rv = clib_bihash_search_inline_16_8 (&st->v4_half_open_hash, &kv4);
+      if (rv == 0)
+	return transport_get_half_open (proto, kv4.value & 0xFFFFFFFF);
+    }
+  else
+    {
+      session_kv6_t kv6;
+
+      st = session_table_get_for_fib_index (FIB_PROTOCOL_IP6, fib_index);
+      if (PREDICT_FALSE (!st))
+	return 0;
+
+      make_v6_ss_kv (&kv6, &lcl->ip6, &rmt->ip6, lcl_port, rmt_port, proto);
+      rv = clib_bihash_search_inline_48_8 (&st->v6_session_hash, &kv6);
+      if (rv == 0)
+	{
+	  s = session_get_from_handle (kv6.value);
+	  return transport_get_connection (proto, s->connection_index,
+					   s->thread_index);
+	}
+
+      /* Try half-open connections */
+      rv = clib_bihash_search_inline_48_8 (&st->v6_half_open_hash, &kv6);
+      if (rv == 0)
+	return transport_get_half_open (proto, kv6.value & 0xFFFFFFFF);
+    }
+  return 0;
+}
+
 session_error_t
 vnet_session_rule_add_del (session_rule_add_del_args_t *args)
 {
diff --git a/src/vnet/session/session_lookup.h b/src/vnet/session/session_lookup.h
index 9f56af20a87..8f9ff7ee9bc 100644
--- a/src/vnet/session/session_lookup.h
+++ b/src/vnet/session/session_lookup.h
@@ -72,6 +72,9 @@ transport_connection_t *session_lookup_connection (u32 fib_index,
 						   ip46_address_t * rmt,
 						   u16 lcl_port, u16 rmt_port,
 						   u8 proto, u8 is_ip4);
+transport_connection_t *
+session_lookup_6tuple (u32 fib_index, ip46_address_t *lcl, ip46_address_t *rmt,
+		       u16 lcl_port, u16 rmt_port, u8 proto, u8 is_ip4);
 session_t *session_lookup_listener4 (u32 fib_index, ip4_address_t * lcl,
 				     u16 lcl_port, u8 proto, u8 use_wildcard);
 session_t *session_lookup_listener6 (u32 fib_index, ip6_address_t * lcl,
diff --git a/src/vnet/session/transport.c b/src/vnet/session/transport.c
index e8c9490decb..c58d5900650 100644
--- a/src/vnet/session/transport.c
+++ b/src/vnet/session/transport.c
@@ -657,8 +657,8 @@ transport_alloc_local_port (u8 proto, ip46_address_t *lcl_addr,
 	break;
 
       /* IP:port pair already in use, check if 6-tuple available */
-      if (session_lookup_connection (rmt->fib_index, lcl_addr, &rmt->ip, port,
-				     rmt->port, proto, rmt->is_ip4))
+      if (session_lookup_6tuple (rmt->fib_index, lcl_addr, &rmt->ip, port,
+				 rmt->port, proto, rmt->is_ip4))
 	continue;
 
       /* 6-tuple is available so increment lcl endpoint refcount */
@@ -787,9 +787,9 @@ transport_alloc_local_endpoint (u8 proto, transport_endpoint_cfg_t * rmt_cfg,
 	return 0;
 
       /* IP:port pair already in use, check if 6-tuple available */
-      if (session_lookup_connection (rmt->fib_index, lcl_addr, &rmt->ip,
-				     rmt_cfg->peer.port, rmt->port, proto,
-				     rmt->is_ip4))
+      if (session_lookup_6tuple (rmt->fib_index, lcl_addr, &rmt->ip,
+				 rmt_cfg->peer.port, rmt->port, proto,
+				 rmt->is_ip4))
 	return SESSION_E_PORTINUSE;
 
       /* 6-tuple is available so increment lcl endpoint refcount */