gt: support a single gateway for non-local traffic

This patch allows Grantor servers to support a single gateway for non-local traffic and still avoid having an LPM lookup. It also demonstrates the network configurations for a deployment scenario, as described in AltraMayor#267 and AltraMayor#417.
mengxiang0811 · Jul 26, 2020 · ffdef52 · ffdef52
1 parent 1c0161f
commit ffdef52
Showing 1 changed file with 57 additions and 39 deletions.
diff --git a/gt/main.c b/gt/main.c
@@ -535,46 +535,10 @@ gt_neigh_get_ether_cache(struct neighbor_hash_table *neigh,
 	uint16_t inner_ip_ver, void *ip_dst, struct gatekeeper_if *iface)
 {
 	int ret;
-	char ip[128];
 	struct ether_cache *eth_cache = lookup_ether_cache(neigh, ip_dst);
 	if (eth_cache != NULL)
 		return eth_cache;
 
-	if (inner_ip_ver == RTE_ETHER_TYPE_IPV4) {
-		if (!ip4_same_subnet(iface->ip4_addr.s_addr,
-				*(uint32_t *)ip_dst, iface->ip4_mask.s_addr)) {
-			if (inet_ntop(AF_INET, ip_dst,
-					ip, sizeof(ip)) == NULL) {
-				GT_LOG(ERR,
-					"%s: failed to convert a number to an IPv4 address (%s)\n",
-					__func__, strerror(errno));
-				return NULL;
-			}
-
-			GT_LOG(WARNING,
-				"%s: receiving an IPv4 packet with destination IP address %s, which is not on the same subnet as the GT server\n",
-				__func__, ip);
-			return NULL;
-		}
-	} else if (likely(inner_ip_ver == RTE_ETHER_TYPE_IPV6)) {
-		if (!ip6_same_subnet(&iface->ip6_addr, ip_dst,
-				&iface->ip6_mask)) {
-			if (inet_ntop(AF_INET6, ip_dst,
-					ip, sizeof(ip)) == NULL) {
-				GT_LOG(ERR,
-					"%s: failed to convert a number to an IPv6 address (%s)\n",
-					__func__, strerror(errno));
-				return NULL;
-			}
-
-			GT_LOG(WARNING,
-				"%s: receiving an IPv6 packet with destination IP address %s, which is not on the same subnet as the GT server\n",
-				__func__, ip);
-			return NULL;
-		}
-	} else
-		return NULL;
-
 	eth_cache = get_new_ether_cache(neigh);
 	if (eth_cache == NULL) {
 		ret = drop_cache_entry_randomly(neigh, inner_ip_ver);
@@ -620,9 +584,13 @@ static int
 decap_and_fill_eth(struct rte_mbuf *m, struct gt_config *gt_conf,
 	struct gt_packet_headers *pkt_info, struct gt_instance *instance)
 {
-	struct neighbor_hash_table *neigh;
+	char ip[128];
+	struct neighbor_hash_table *neigh = NULL;
 	struct ether_cache *eth_cache;
 	void *ip_dst;
+	bool is_not_neighbor = false;
+	struct rte_ether_hdr eth_hdr_tmp;
+	struct rte_ether_hdr *raw_eth;
 	int bytes_to_add;
 
 	if (pkt_info->inner_ip_ver == RTE_ETHER_TYPE_IPV4) {
@@ -643,8 +611,24 @@ decap_and_fill_eth(struct rte_mbuf *m, struct gt_config *gt_conf,
 			set_ipv4_checksum(&gt_conf->net->front, m, inner_ipv4_hdr);
 		}
 
-		neigh = &instance->neigh;
 		ip_dst = &inner_ipv4_hdr->dst_addr;
+
+		if (!ip4_same_subnet(iface->ip4_addr.s_addr,
+				*(uint32_t *)ip_dst, iface->ip4_mask.s_addr)) {
+			if (inet_ntop(AF_INET, ip_dst,
+					ip, sizeof(ip)) == NULL) {
+				GT_LOG(ERR,
+					"%s: failed to convert a number to an IPv4 address (%s)\n",
+					__func__, strerror(errno));
+				return -1;
+			}
+
+			is_not_neighbor = true;
+			raw_eth = (struct rte_ether_hdr *)pkt_info->l2_hdr;
+			rte_ether_addr_copy(&raw_eth->s_addr, &eth_hdr_tmp.d_addr);
+			rte_ether_addr_copy(&raw_eth->d_addr, &eth_hdr_tmp.s_addr);
+		} else
+			neigh = &instance->neigh;
 	} else if (likely(pkt_info->inner_ip_ver == RTE_ETHER_TYPE_IPV6)) {
 		/*
 		 * Since there's no checksum in the IPv6 header, skip the
@@ -656,8 +640,24 @@ decap_and_fill_eth(struct rte_mbuf *m, struct gt_config *gt_conf,
 			inner_ipv6_hdr->vtc_flow |=
 				rte_cpu_to_be_32(IPTOS_ECN_CE << 20);
 
-		neigh = &instance->neigh6;
 		ip_dst = inner_ipv6_hdr->dst_addr;
+
+		if (!ip6_same_subnet(&iface->ip6_addr, ip_dst,
+				&iface->ip6_mask)) {
+			if (inet_ntop(AF_INET6, ip_dst,
+					ip, sizeof(ip)) == NULL) {
+				GT_LOG(ERR,
+					"%s: failed to convert a number to an IPv6 address (%s)\n",
+					__func__, strerror(errno));
+				return -1;
+			}
+
+			is_not_neighbor = true;
+			raw_eth = (struct rte_ether_hdr *)pkt_info->l2_hdr;
+			rte_ether_addr_copy(&raw_eth->s_addr, &eth_hdr_tmp.d_addr);
+			rte_ether_addr_copy(&raw_eth->d_addr, &eth_hdr_tmp.s_addr);
+		} else
+			neigh = &instance->neigh6;
 	} else
 		return -1;
 
@@ -671,6 +671,24 @@ decap_and_fill_eth(struct rte_mbuf *m, struct gt_config *gt_conf,
 		return -1;
 	}
 
+	if (is_not_neighbor) {
+		struct rte_ether_hdr *eth_hdr =
+			rte_pktmbuf_mtod(m, struct rte_ether_hdr *);
+
+		rte_memcpy(eth_hdr, &eth_hdr_tmp, gt_conf->net->front.l2_len_out);
+		m->l2_len = gt_conf->net->front.l2_len_out;
+
+		if (iface->vlan_insert) {
+			fill_vlan_hdr(eth_hdr, iface->vlan_tag_be,
+			pkt_info->outer_ethertype);
+		} else {
+			eth_hdr->ether_type =
+			rte_cpu_to_be_16(pkt_info->outer_ethertype);
+		}
+
+		return 0;
+	}
+
 	/*
 	 * The destination MAC address comes from LLS block.
 	 */