Fix ICMP echo reply punt path

Add ICMP echo reply punt logic in ip[46]-icmp-echo-reply (ping) nodes.
ICMP echo reply packets corresponding to the locally (VPP) originated
ICMP echo requests are still dropped as before. Rest of the (unknown)
ICMP echo reply packets are pushed to the “error-punt” node.

Also added ICMP echo packet (id/seq) trace information

Change-Id: I998198430dedc9b4d771b6aff2a97f18598663f9
Signed-off-by: Alexander Popovsky <apopovsk@cisco.com>

2 files changed, 48 insertions, 21 deletions

diff --git a/vnet/vnet/ip/ping.c b/vnet/vnet/ip/ping.c
index bd714f19..0bf83e9e 100644
--- a/vnet/vnet/ip/ping.c
+++ b/vnet/vnet/ip/ping.c
@@ -29,14 +29,16 @@
 
 
 u8 *
-format_icmp4_input_trace (u8 * s, va_list * va)
+format_icmp_echo_trace (u8 * s, va_list * va)
 {
   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*va, vlib_main_t *);
   CLIB_UNUSED (vlib_node_t * node) = va_arg (*va, vlib_node_t *);
-  icmp4_input_trace_t *t = va_arg (*va, icmp4_input_trace_t *);
+  icmp_echo_trace_t *t = va_arg (*va, icmp_echo_trace_t *);
 
-  s = format (s, "%U",
-              format_ip4_header, t->packet_data, sizeof (t->packet_data));
+  s = format (s, "ICMP echo id %d seq %d%s",
+              clib_net_to_host_u16(t->id),
+              clib_net_to_host_u16(t->seq),
+              t->bound ? "" : " (unknown)");
 
   return s;
 }
@@ -50,7 +52,7 @@ format_icmp4_input_trace (u8 * s, va_list * va)
  *
  */
 
-static void
+static int
 signal_ip46_icmp_reply_event (vlib_main_t * vm,
                               u8 event_type, vlib_buffer_t * b0)
 {
@@ -73,13 +75,13 @@ signal_ip46_icmp_reply_event (vlib_main_t * vm,
       }
       break;
     default:
-      return;
+      return 0;
     }
 
   uword *p = hash_get (pm->ping_run_by_icmp_id,
                        clib_net_to_host_u16 (net_icmp_id));
   if (!p)
-    return;
+    return 0;
 
   ping_run_t *pr = vec_elt_at_index (pm->ping_runs, p[0]);
   if (vlib_buffer_alloc (vm, &bi0_copy, 1) == 1)
@@ -90,6 +92,7 @@ signal_ip46_icmp_reply_event (vlib_main_t * vm,
   /* If buffer_alloc failed, bi0_copy == 0 - just signaling an event. */
 
   vlib_process_signal_event (vm, pr->cli_process_id, event_type, bi0_copy);
+  return 1;
 }
 
 /*
@@ -113,10 +116,19 @@ ip6_icmp_echo_reply_node_fn (vlib_main_t * vm,
       bi0 = from[0];
       b0 = vlib_get_buffer (vm, bi0);
 
-      signal_ip46_icmp_reply_event (vm, PING_RESPONSE_IP6, b0);
+      next0 = signal_ip46_icmp_reply_event (vm, PING_RESPONSE_IP6, b0) ?
+        ICMP6_ECHO_REPLY_NEXT_DROP : ICMP6_ECHO_REPLY_NEXT_PUNT;
+
+      if (PREDICT_FALSE(b0->flags & VLIB_BUFFER_IS_TRACED)) 
+         {
+           icmp6_echo_request_header_t *h0 = vlib_buffer_get_current (b0);
+           icmp_echo_trace_t *tr = vlib_add_trace (vm, node, b0, sizeof (*tr));
+           tr->id = h0->icmp_echo.id;
+           tr->seq = h0->icmp_echo.seq;
+           tr->bound = (next0 == ICMP6_ECHO_REPLY_NEXT_DROP);
+         }
 
-      /* push this pkt to the next graph node, always error-drop */
-      next0 = ICMP6_ECHO_REPLY_NEXT_NORMAL;
+      /* push this pkt to the next graph node */
       vlib_set_next_frame_buffer (vm, node, next0, bi0);
 
       from += 1;
@@ -132,10 +144,11 @@ VLIB_REGISTER_NODE (ip6_icmp_echo_reply_node, static) =
   .function = ip6_icmp_echo_reply_node_fn,
   .name = "ip6-icmp-echo-reply",
   .vector_size = sizeof (u32),
-  .format_trace = format_icmp6_input_trace,
+  .format_trace = format_icmp_echo_trace,
   .n_next_nodes = ICMP6_ECHO_REPLY_N_NEXT,
   .next_nodes = {
-    [ICMP6_ECHO_REPLY_NEXT_NORMAL] = "error-drop",
+    [ICMP6_ECHO_REPLY_NEXT_DROP] = "error-drop",
+    [ICMP6_ECHO_REPLY_NEXT_PUNT] = "error-punt",
   },
 };
 /* *INDENT-ON* */
@@ -161,10 +174,19 @@ ip4_icmp_echo_reply_node_fn (vlib_main_t * vm,
       bi0 = from[0];
       b0 = vlib_get_buffer (vm, bi0);
 
-      /* push this pkt to the next graph node, always error-drop */
-      signal_ip46_icmp_reply_event (vm, PING_RESPONSE_IP4, b0);
+      next0 = signal_ip46_icmp_reply_event (vm, PING_RESPONSE_IP4, b0) ?
+        ICMP4_ECHO_REPLY_NEXT_DROP : ICMP4_ECHO_REPLY_NEXT_PUNT;
+
+      if (PREDICT_FALSE(b0->flags & VLIB_BUFFER_IS_TRACED)) 
+         {
+           icmp4_echo_request_header_t *h0 = vlib_buffer_get_current (b0);
+           icmp_echo_trace_t *tr = vlib_add_trace (vm, node, b0, sizeof (*tr));
+           tr->id = h0->icmp_echo.id;
+           tr->seq = h0->icmp_echo.seq;
+           tr->bound = (next0 == ICMP4_ECHO_REPLY_NEXT_DROP);
+         }
 
-      next0 = ICMP4_ECHO_REPLY_NEXT_NORMAL;
+      /* push this pkt to the next graph node */
       vlib_set_next_frame_buffer (vm, node, next0, bi0);
 
       from += 1;
@@ -180,10 +202,11 @@ VLIB_REGISTER_NODE (ip4_icmp_echo_reply_node, static) =
   .function = ip4_icmp_echo_reply_node_fn,
   .name = "ip4-icmp-echo-reply",
   .vector_size = sizeof (u32),
-  .format_trace = format_icmp4_input_trace,
+  .format_trace = format_icmp_echo_trace,
   .n_next_nodes = ICMP4_ECHO_REPLY_N_NEXT,
   .next_nodes = {
-    [ICMP4_ECHO_REPLY_NEXT_NORMAL] = "error-drop",
+    [ICMP4_ECHO_REPLY_NEXT_DROP] = "error-drop",
+    [ICMP4_ECHO_REPLY_NEXT_PUNT] = "error-punt",
   },
 };
 /* *INDENT-ON* */
diff --git a/vnet/vnet/ip/ping.h b/vnet/vnet/ip/ping.h
index 7d2db423..579638cf 100644
--- a/vnet/vnet/ip/ping.h
+++ b/vnet/vnet/ip/ping.h
@@ -78,19 +78,23 @@ typedef CLIB_PACKED(struct {
 
 
 typedef struct {
-  u8 packet_data[64];
-} icmp4_input_trace_t;
+  u16 id;
+  u16 seq;
+  u8 bound;
+} icmp_echo_trace_t;
 
 
 
 
 typedef enum {
-  ICMP6_ECHO_REPLY_NEXT_NORMAL,
+  ICMP6_ECHO_REPLY_NEXT_DROP,
+  ICMP6_ECHO_REPLY_NEXT_PUNT,
   ICMP6_ECHO_REPLY_N_NEXT,
 } icmp6_echo_reply_next_t;
 
 typedef enum {
-  ICMP4_ECHO_REPLY_NEXT_NORMAL,
+  ICMP4_ECHO_REPLY_NEXT_DROP,
+  ICMP4_ECHO_REPLY_NEXT_PUNT,
   ICMP4_ECHO_REPLY_N_NEXT,
 } icmp4_echo_reply_next_t;