ipsec: Changes to make ipsec encoder/decoders reusable by the plugins

[vpp.git] / src / vnet / buffer.h

diff --git a/src/vnet/buffer.h b/src/vnet/buffer.h
index d160ae8..59a8256 100644 (file)
--- a/src/vnet/buffer.h
+++ b/src/vnet/buffer.h
@@ -168,7 +168,7 @@ typedef struct
          };
 
          /* Rewrite length */
-         u32 save_rewrite_length;
+         u8 save_rewrite_length;
 
          /* MFIB RPF ID */
          u32 rpf_id;
@@ -185,8 +185,9 @@ typedef struct
        /* reassembly */
        union
        {
-         /* group input/handoff as handoff is done before input is consumed,
-          * this way we can handoff while keeping input variables intact */
+         /* group input/output/handoff to simplify the code, this way:
+          * we can handoff while keeping input variables intact
+          * and also we can write the output and still use next_index later */
          struct
          {
            /* input variables */
@@ -200,23 +201,23 @@ typedef struct
            {
              u16 owner_thread_index;
            };
-         };
-         /* output variables */
-         struct
-         {
-           union
+           /* output variables */
+           struct
            {
-             /* shallow virtual reassembly output variables */
-             struct
+             union
              {
-               u8 ip_proto;    /* protocol in ip header */
-               u16 l4_src_port;        /* tcp/udp/icmp src port */
-               u16 l4_dst_port;        /* tcp/udp/icmp dst port */
-             };
-             /* full reassembly output variables */
-             struct
-             {
-               u16 estimated_mtu;      /* estimated MTU calculated during reassembly */
+               /* shallow virtual reassembly output variables */
+               struct
+               {
+                 u8 ip_proto;  /* protocol in ip header */
+                 u16 l4_src_port;      /* tcp/udp/icmp src port */
+                 u16 l4_dst_port;      /* tcp/udp/icmp dst port */
+               };
+               /* full reassembly output variables */
+               struct
+               {
+                 u16 estimated_mtu;    /* estimated MTU calculated during reassembly */
+               };
              };
            };
          };
@@ -249,7 +250,7 @@ typedef struct
       u8 pyld_proto:3;         /* dpo_proto_t */
       u8 rsvd:5;
       /* Rewrite length */
-      u32 save_rewrite_length;
+      u8 save_rewrite_length;
       /* Save the mpls header length including all label stack */
       u8 mpls_hdr_length;
       /*
@@ -379,6 +380,16 @@ typedef struct
   };
 } vnet_buffer_opaque_t;
 
+#define VNET_REWRITE_TOTAL_BYTES (VLIB_BUFFER_PRE_DATA_SIZE)
+
+STATIC_ASSERT (STRUCT_SIZE_OF (vnet_buffer_opaque_t, ip.save_rewrite_length)
+              == STRUCT_SIZE_OF (vnet_buffer_opaque_t,
+                                 mpls.save_rewrite_length)
+              && STRUCT_SIZE_OF (vnet_buffer_opaque_t,
+                                 mpls.save_rewrite_length) == 1
+              && VNET_REWRITE_TOTAL_BYTES < UINT8_MAX,
+              "save_rewrite_length member must be able to hold the max value of rewrite length");
+
 /*
  * The opaque field of the vlib_buffer_t is interpreted as a
  * vnet_buffer_opaque_t. Hence it should be big enough to accommodate one.