* Whenever ICMP error packet is trapped for flow setup,

  parse the inner payload and frame the flow key.
  Test case for same
Closes-bug:#1423848

Change-Id: I9c088888487b45bcf3ef34156adb64a83260264c

src/vnsw/agent/pkt/pkt_handler.cc

@@ -273,6 +273,22 @@ uint8_t *PktHandler::ParseIpPacket(PktInfo *pkt_info,
         if (icmp->type == ICMP_ECHO || icmp->type == ICMP_ECHOREPLY) {
             pkt_info->dport = ICMP_ECHOREPLY;
             pkt_info->sport = htons(icmp->un.echo.id);
+        } else if ((pkt_info->agent_hdr.cmd == AGENT_TRAP_FLOW_MISS ||
+                    pkt_info->agent_hdr.cmd == AGENT_TRAP_ECMP_RESOLVE) &&
+                    (icmp->type == ICMP_DEST_UNREACH ||
+                     icmp->type == ICMP_TIME_EXCEEDED)) {
+            //Agent has to look at inner payload
+            //and recalculate the parameter
+            ParseIpPacket(pkt_info, pkt_type, pkt + sizeof(icmphdr));
+            //Swap the key parameter, which would be used as key
+            uint32_t src_ip = pkt_info->ip_saddr;
+            pkt_info->ip_saddr = pkt_info->ip_daddr;
+            pkt_info->ip_daddr = src_ip;
+            if (pkt_info->ip_proto != IPPROTO_ICMP) {
+                uint16_t port = pkt_info->sport;
+                pkt_info->sport = pkt_info->dport;
+                pkt_info->dport = port;
+            }
         } else {
             pkt_info->sport = 0;
         }

src/vnsw/agent/pkt/test/test_pkt_flow.cc

@@ -3452,6 +3452,62 @@ TEST_F(FlowTest, FlowPolicyUuid_16) {
     client->WaitForIdle();
 }
 
+TEST_F(FlowTest, FlowIcmpError_1) {
+    //Send a ICMP error packet with payload
+    //of icmp, verify flow is setup properly
+    TxIpIcmpErrorPacket(flow1->id(), vm1_ip, vm2_ip, IPPROTO_ICMP, 1000, 0,
+                         10, flow1->vrf()->vrf_id(), ICMP_DEST_UNREACH);
+    client->WaitForIdle();
+
+    uint32_t vrf_id = VrfGet("vrf5")->vrf_id();
+    uint32_t nh_id = flow0->flow_key_nh()->id();
+    uint32_t rev_nh_id = flow1->flow_key_nh()->id();
+
+    FlowEntry *fe = FlowGet(vrf_id, vm1_ip, vm2_ip, IPPROTO_ICMP, 1000, 0, nh_id);
+    EXPECT_TRUE(fe != NULL);
+
+    FlowEntry *rfe = FlowGet(vrf_id, vm2_ip, vm1_ip, IPPROTO_ICMP, 1000, 0, rev_nh_id);
+    EXPECT_TRUE(rfe != NULL);
+}
+
+TEST_F(FlowTest, FlowIcmpError_2) {
+    //Send a ICMP error packet with payload
+    //of UDP, verify flow is setup properly
+    TxIpIcmpErrorPacket(flow1->id(), vm1_ip, vm2_ip, IPPROTO_UDP, 10, 20,
+                         11, flow1->vrf()->vrf_id(), ICMP_DEST_UNREACH);
+    client->WaitForIdle();
+
+    uint32_t vrf_id = VrfGet("vrf5")->vrf_id();
+    uint32_t nh_id = flow0->flow_key_nh()->id();
+    uint32_t rev_nh_id = flow1->flow_key_nh()->id();
+
+    FlowEntry *fe = FlowGet(vrf_id, vm1_ip, vm2_ip, IPPROTO_UDP, 10, 20, nh_id);
+    EXPECT_TRUE(fe != NULL);
+
+    FlowEntry *rfe = FlowGet(vrf_id, vm2_ip, vm1_ip, IPPROTO_UDP, 20, 10,
+                             rev_nh_id);
+    EXPECT_TRUE(rfe != NULL);
+}
+
+TEST_F(FlowTest, FlowIcmpError_3) {
+    //Send a ICMP error packet with payload
+    //of TCP, verify flow is setup properly
+    TxIpIcmpErrorPacket(flow1->id(), vm1_ip, vm2_ip, IPPROTO_TCP, 10, 20,
+                         12, flow1->vrf()->vrf_id(), ICMP_TIME_EXCEEDED);
+    client->WaitForIdle();
+
+    uint32_t vrf_id = VrfGet("vrf5")->vrf_id();
+    uint32_t nh_id = flow0->flow_key_nh()->id();
+    uint32_t rev_nh_id = flow1->flow_key_nh()->id();
+
+    FlowEntry *fe = FlowGet(vrf_id, vm1_ip, vm2_ip, IPPROTO_TCP,  10, 20, nh_id);
+    EXPECT_TRUE(fe != NULL);
+
+    FlowEntry *rfe = FlowGet(vrf_id, vm2_ip, vm1_ip, IPPROTO_TCP, 20, 10,
+                             rev_nh_id);
+    EXPECT_TRUE(rfe != NULL);
+}
+
 int main(int argc, char *argv[]) {
     GETUSERARGS();
 

src/vnsw/agent/pkt/test/test_pkt_util.cc

@@ -186,3 +186,29 @@ void TxTcpMplsPacket(int ifindex, const char *out_sip,
     delete pkt;
 }
 
+void TxIpIcmpErrorPacket(int ifindex, const char *sip, const char *dip,
+                         int proto, uint16_t sport, uint16_t dport,
+                         int hash_id, int vrf, int icmp_err) {
+    PktGen *pkt = new PktGen();
+
+    pkt->AddEthHdr("00:00:00:00:00:01", "00:00:00:00:00:02", 0x800);
+    pkt->AddAgentHdr(ifindex, AGENT_TRAP_FLOW_MISS, hash_id, vrf) ;
+    pkt->AddEthHdr("00:00:5E:00:01:00", "00:00:00:00:00:01", 0x800);
+    pkt->AddIpHdr(dip, sip, 1);
+    pkt->AddIcmpHdr(icmp_err, 0);
+
+    pkt->AddIpHdr(sip, dip, proto);
+    if (proto == IPPROTO_ICMP) {
+        pkt->AddIcmpHdr(ICMP_ECHO, sport);
+    } else if (proto == IPPROTO_TCP) {
+        pkt->AddTcpHdr(sport, dport, false, false, true, 64);
+    } else if (proto == IPPROTO_UDP) {
+        pkt->AddUdpHdr(sport, dport, 64);
+    }
+    uint8_t *ptr(new uint8_t[pkt->GetBuffLen()]);
+    memcpy(ptr, pkt->GetBuff(), pkt->GetBuffLen());
+    Agent::GetInstance()->pkt()->pkt_handler()->HandleRcvPkt(ptr,
+                                                             pkt->GetBuffLen(),
+                                                             pkt->GetBuffLen());
+    delete pkt;
+}

src/vnsw/agent/pkt/test/test_pkt_util.h

@@ -55,5 +55,7 @@ extern void TxTcpMplsPacket(int ifindex, const char *out_sip,
                                const char *out_dip, uint32_t label,
                                const char *sip, const char *dip, uint16_t sport,
                                uint16_t dport, bool ack, int hash_id = 1);
-
+void TxIpIcmpErrorPacket(int ifindex, const char *sip, const char *dip,
+                         int proto, uint16_t sport, uint16_t dport,
+                         int hash_id, int vrf, int icmp_err);
 #endif // __TEST_PKT_UTIL_H__

src/vnsw/agent/test/pkt_gen.h

@@ -245,9 +245,17 @@ class PktGen {
         struct icmphdr *icmp = (struct icmphdr *)(buff + len);
         icmp->type = 0;
         icmp->un.echo.id = 0;
-        len += sizeof(icmphdr) + len;
+        len += sizeof(icmphdr);
     };
 
+    void AddIcmpHdr(uint8_t type, uint16_t id) {
+        struct icmphdr *icmp = (struct icmphdr *)(buff + len);
+        icmp->type = type;
+        icmp->un.echo.id = htons(id);
+        len += sizeof(icmphdr);
+    };
+
+
     void AddGreHdr(uint16_t proto) {
         GreHdr *gre = (GreHdr *)(buff + len);
         gre->flags = 0;