api: verify message size on receipt

When a message is received, verify that it's sufficiently large to
accomodate any VLAs within message. To do that, we need a way to
calculate message size including any VLAs. This patch adds such
funcionality to vppapigen and necessary C code to use those to validate
message size on receipt. Drop messages which are malformed.

Type: improvement
Signed-off-by: Klement Sekera <ksekera@cisco.com>
Change-Id: I2903aa21dee84be6822b064795ba314de46c18f4

5 files changed, 25 insertions, 4 deletions

diff --git a/src/vnet/ip/ip_api.c b/src/vnet/ip/ip_api.c
index e197057d8c5..b1b7ff3a7ae 100644
--- a/src/vnet/ip/ip_api.c
+++ b/src/vnet/ip/ip_api.c
@@ -514,7 +514,9 @@ vl_api_add_del_ip_punt_redirect_v2_t_handler (
     goto out;
 
   if (0 != n_paths)
-    vec_validate (rpaths, n_paths - 1);
+    {
+      vec_validate (rpaths, n_paths - 1);
+    }
 
   for (ii = 0; ii < n_paths; ii++)
     {
diff --git a/src/vnet/ip/ip_test.c b/src/vnet/ip/ip_test.c
index c47cd3d208e..f87b47f8912 100644
--- a/src/vnet/ip/ip_test.c
+++ b/src/vnet/ip/ip_test.c
@@ -36,6 +36,10 @@
 #include <vnet/ip/ip.api.h>
 #undef vl_endianfun
 
+#define vl_calcsizefun
+#include <vnet/ip/ip.api.h>
+#undef vl_calcsizefun
+
 typedef struct
 {
   /* API message ID base */
diff --git a/src/vnet/ipsec/ipsec_test.c b/src/vnet/ipsec/ipsec_test.c
index f399032eb9a..f3a9992e916 100644
--- a/src/vnet/ipsec/ipsec_test.c
+++ b/src/vnet/ipsec/ipsec_test.c
@@ -26,6 +26,10 @@
 #include <vnet/ipsec/ipsec.api.h>
 #undef vl_endianfun
 
+#define vl_calcsizefun
+#include <vnet/ipsec/ipsec.api.h>
+#undef vl_calcsizefun
+
 typedef struct
 {
   /* API message ID base */
diff --git a/src/vnet/l2/l2_test.c b/src/vnet/l2/l2_test.c
index c7cd1d255c1..3be4a46223d 100644
--- a/src/vnet/l2/l2_test.c
+++ b/src/vnet/l2/l2_test.c
@@ -28,6 +28,10 @@
 #include <vnet/l2/l2.api.h>
 #undef vl_endianfun
 
+#define vl_calcsizefun
+#include <vnet/l2/l2.api.h>
+#undef vl_calcsizefun
+
 typedef struct
 {
   /* API message ID base */
diff --git a/src/vnet/srmpls/sr_mpls_api.c b/src/vnet/srmpls/sr_mpls_api.c
index 7d42f1ba451..45107f08ab1 100644
--- a/src/vnet/srmpls/sr_mpls_api.c
+++ b/src/vnet/srmpls/sr_mpls_api.c
@@ -39,6 +39,10 @@
 #include <vnet/srmpls/sr_mpls.api.h>
 #undef vl_endianfun
 
+#define vl_calcsizefun
+#include <vnet/srmpls/sr_mpls.api.h>
+#undef vl_calcsizefun
+
 #define vl_printfun
 #include <vnet/srmpls/sr_mpls.api.h>
 #undef vl_printfun
@@ -194,7 +198,8 @@ sr_mpls_api_hookup (vlib_main_t * vm)
     REPLY_MSG_ID_BASE + VL_API_##N, #n, vl_api_##n##_t_handler,               \
     vl_noop_handler, vl_api_##n##_t_endian, vl_api_##n##_t_print,             \
     sizeof (vl_api_##n##_t), 1, vl_api_##n##_t_print_json,                    \
-    vl_api_##n##_t_tojson, vl_api_##n##_t_fromjson);
+    vl_api_##n##_t_tojson, vl_api_##n##_t_fromjson,                           \
+    vl_api_##n##_t_calc_size);
   foreach_vpe_api_msg;
 #undef _
 
@@ -207,7 +212,8 @@ sr_mpls_api_hookup (vlib_main_t * vm)
     vl_api_sr_mpls_policy_add_t_handler, vl_noop_handler,
     vl_api_sr_mpls_policy_add_t_endian, vl_api_sr_mpls_policy_add_t_print, 256,
     1, vl_api_sr_mpls_policy_add_t_print_json,
-    vl_api_sr_mpls_policy_mod_t_tojson, vl_api_sr_mpls_policy_mod_t_fromjson);
+    vl_api_sr_mpls_policy_add_t_tojson, vl_api_sr_mpls_policy_add_t_fromjson,
+    vl_api_sr_mpls_policy_add_t_calc_size);
 
   /*
    * Manually register the sr policy mod msg, so we trace enough bytes
@@ -218,7 +224,8 @@ sr_mpls_api_hookup (vlib_main_t * vm)
     vl_api_sr_mpls_policy_mod_t_handler, vl_noop_handler,
     vl_api_sr_mpls_policy_mod_t_endian, vl_api_sr_mpls_policy_mod_t_print, 256,
     1, vl_api_sr_mpls_policy_mod_t_print_json,
-    vl_api_sr_mpls_policy_mod_t_tojson, vl_api_sr_mpls_policy_mod_t_fromjson);
+    vl_api_sr_mpls_policy_mod_t_tojson, vl_api_sr_mpls_policy_mod_t_fromjson,
+    vl_api_sr_mpls_policy_mod_t_calc_size);
 
   /*
    * Set up the (msg_name, crc, message-id) table