ip: reassembly: handle atomic fragments correctly

[vpp.git] / src / vnet / ip / reass / ip6_sv_reass.c

diff --git a/src/vnet/ip/reass/ip6_sv_reass.c b/src/vnet/ip/reass/ip6_sv_reass.c
index fb435ba..3656c5a 100644 (file)
--- a/src/vnet/ip/reass/ip6_sv_reass.c
+++ b/src/vnet/ip/reass/ip6_sv_reass.c
@@ -215,7 +215,7 @@ format_ip6_sv_reass_trace (u8 * s, va_list * args)
                clib_net_to_host_u16 (t->l4_dst_port));
       break;
     case REASS_PASSTHROUGH:
-      s = format (s, "[not-fragmented]");
+      s = format (s, "[not fragmented or atomic fragment]");
       break;
     }
   return s;
@@ -532,13 +532,24 @@ ip6_sv_reassembly_inline (vlib_main_t * vm,
          ip6_header_t *ip0 = vlib_buffer_get_current (b0);
          ip6_frag_hdr_t *frag_hdr;
          ip6_ext_hdr_chain_t hdr_chain;
+         bool is_atomic_fragment = false;
 
          int res = ip6_ext_header_walk (
            b0, ip0, IP_PROTOCOL_IPV6_FRAGMENTATION, &hdr_chain);
+         if (res >= 0 &&
+             hdr_chain.eh[res].protocol == IP_PROTOCOL_IPV6_FRAGMENTATION)
+           {
+             frag_hdr =
+               ip6_ext_next_header_offset (ip0, hdr_chain.eh[res].offset);
+             is_atomic_fragment = (0 == ip6_frag_hdr_offset (frag_hdr) &&
+                                   !ip6_frag_hdr_more (frag_hdr));
+           }
+
          if (res < 0 ||
-             hdr_chain.eh[res].protocol != IP_PROTOCOL_IPV6_FRAGMENTATION)
+             hdr_chain.eh[res].protocol != IP_PROTOCOL_IPV6_FRAGMENTATION ||
+             is_atomic_fragment)
            {
-             // this is a regular packet - no fragmentation
+             // this is a regular unfragmented packet or an atomic fragment
              if (!ip6_get_port
                  (vm, b0, ip0, b0->current_length,
                   &(vnet_buffer (b0)->ip.reass.ip_proto),
@@ -565,10 +576,10 @@ ip6_sv_reassembly_inline (vlib_main_t * vm,
                }
              goto packet_enqueue;
            }
-         frag_hdr =
-           ip6_ext_next_header_offset (ip0, hdr_chain.eh[res].offset);
+
          vnet_buffer (b0)->ip.reass.ip6_frag_hdr_offset =
            hdr_chain.eh[res].offset;
+
          if (0 == ip6_frag_hdr_offset (frag_hdr))
            {
              // first fragment - verify upper-layer is present