[HICN-562] Ignore ghost interfaces in VPP ollectd plugin

Sometimes there are interfaces listed by VPP statistics API that cannot
be read from. This results in segfaults. This patch makes the VPP
collectd plugin ignore them.

Signed-off-by: Olivier Roques <oroques+fdio@cisco.com>
Change-Id: I3b626b5bf553dc045c9fe46828889c47ea122020

1 files changed, 16 insertions, 9 deletions

diff --git a/telemetry/vpp-collectd/vpp/vpp.c b/telemetry/vpp-collectd/vpp/vpp.c
index 36a8da86e..ba838a050 100644
--- a/telemetry/vpp-collectd/vpp/vpp.c
+++ b/telemetry/vpp-collectd/vpp/vpp.c
@@ -302,9 +302,7 @@ static int vpp_read(void) {
   for (int k = 0; k < vec_len(res); k++) {
     if (res[k].type == STAT_DIR_TYPE_NAME_VECTOR) {
       for (int i = 0; i < vec_len(res[k].name_vector); i++) {
-        if (res[k].name_vector[i]) {
-          vec_add1(interfaces, (char *)res[k].name_vector[i]);
-        }
+        vec_add1(interfaces, (char *)res[k].name_vector[i]);
       }
       break;
     }
@@ -320,13 +318,18 @@ static int vpp_read(void) {
     case STAT_DIR_TYPE_COUNTER_VECTOR_SIMPLE:
       for (int k = 0; k < vec_len(res[i].simple_counter_vec); k++) {
         for (int j = 0; j < vec_len(res[i].simple_counter_vec[k]); j++) {
-          value_t values[1] = {
-              (value_t){.derive = res[i].simple_counter_vec[k][j]}};
+          if (!interfaces[j]) {
+            continue;
+          }
 
           if (get_data_set(res[i].name, &data_set)) {
             continue;
           }
 
+          value_t values[1] = {
+              (value_t){.derive = res[i].simple_counter_vec[k][j]}
+          };
+
           err = submit(interfaces[j], data_set.type, values, 1, &timestamp);
 
           if (err)
@@ -338,15 +341,19 @@ static int vpp_read(void) {
     case STAT_DIR_TYPE_COUNTER_VECTOR_COMBINED:
       for (int k = 0; k < vec_len(res[i].combined_counter_vec); k++) {
         for (int j = 0; j < vec_len(res[i].combined_counter_vec[k]); j++) {
-          value_t values[2] = {
-              (value_t){.derive = res[i].combined_counter_vec[k][j].packets},
-              (value_t){.derive = res[i].combined_counter_vec[k][j].bytes},
-          };
+          if (!interfaces[j]) {
+            continue;
+          }
 
           if (get_data_set(res[i].name, &data_set)) {
             continue;
           }
 
+          value_t values[2] = {
+              (value_t){.derive = res[i].combined_counter_vec[k][j].packets},
+              (value_t){.derive = res[i].combined_counter_vec[k][j].bytes},
+          };
+
           err = submit(interfaces[j], data_set.type, values, 2, &timestamp);
 
           if (err)