Bugfixing and documentation for SRv6

- Fixed three coverity issues
- Linked SRv6 docs
- Moved sample plugin to examples folder
- Fixed bug with hash. Now everything is using mhash. Potentially in the future we want to do bihash.

Change-Id: Ie03a13c8fecb1e315e67d0596cbd23220779aaf2
Signed-off-by: Pablo Camarillo <pcamaril@cisco.com>

1 files changed, 200 insertions, 0 deletions

diff --git a/src/examples/srv6-sample-localsid/node.c b/src/examples/srv6-sample-localsid/node.c
new file mode 100644
index 00000000000..7bae9cd7c55
--- /dev/null
+++ b/src/examples/srv6-sample-localsid/node.c
@@ -0,0 +1,200 @@
+/*
+ * Copyright (c) 2015 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include <vlib/vlib.h>
+#include <vnet/vnet.h>
+#include <vnet/pg/pg.h>
+#include <vppinfra/error.h>
+#include <srv6-localsid/srv6_localsid_sample.h>
+
+typedef struct {
+  u32 localsid_index;
+} srv6_localsid_sample_trace_t;
+
+/* packet trace format function */
+static u8 * format_srv6_localsid_sample_trace (u8 * s, va_list * args)
+{
+  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
+  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
+  srv6_localsid_sample_trace_t * t = va_arg (*args, srv6_localsid_sample_trace_t *);
+  s = format (s, "SRv6-sample-localsid: localsid_index %d\n",
+              t->localsid_index);
+  return s;
+}
+
+vlib_node_registration_t srv6_localsid_sample_node;
+
+#define foreach_srv6_localsid_counter \
+_(PROCESSED, "srv6-sample-localsid processed packets") \
+_(NO_SRH, "(Error) No SRH.")
+
+typedef enum {
+#define _(sym,str) SRV6_LOCALSID_COUNTER_##sym,
+  foreach_srv6_localsid_counter
+#undef _
+  SRV6_LOCALSID_N_COUNTERS,
+} srv6_localsid_sample_counters;
+
+static char * srv6_localsid_counter_strings[] = {
+#define _(sym,string) string,
+  foreach_srv6_localsid_counter
+#undef _
+};
+
+typedef enum {
+  SRV6_SAMPLE_LOCALSID_NEXT_ERROR,
+  SRV6_SAMPLE_LOCALSID_NEXT_IP6LOOKUP,
+  SRV6_SAMPLE_LOCALSID_N_NEXT,
+} srv6_localsid_sample_next_t;
+
+/**
+ * @brief Function doing End processing. 
+ */
+//Fixme: support OAM (hop-by-hop header) here!
+static_always_inline void
+end_srh_processing (vlib_node_runtime_t * node,
+                    vlib_buffer_t * b0,
+                    ip6_header_t * ip0,
+                    ip6_sr_header_t * sr0,
+                    u32 * next0)
+{
+  ip6_address_t *new_dst0;
+
+  if(PREDICT_TRUE(ip0->protocol == IP_PROTOCOL_IPV6_ROUTE))
+  {
+    if(PREDICT_TRUE(sr0->type == ROUTING_HEADER_TYPE_SR))
+    {
+      if(PREDICT_TRUE(sr0->segments_left != 0))
+      {
+        sr0->segments_left -= 1;
+        new_dst0 = (ip6_address_t *)(sr0->segments);
+        new_dst0 += sr0->segments_left;
+        ip0->dst_address.as_u64[0] = new_dst0->as_u64[0];
+        ip0->dst_address.as_u64[1] = new_dst0->as_u64[1];
+      }
+      else
+      {
+        *next0 = SRV6_SAMPLE_LOCALSID_NEXT_ERROR;
+        b0->error = node->errors[SRV6_LOCALSID_COUNTER_NO_SRH];
+      }
+    }
+    else
+    {
+      /* Error. Routing header of type != SR */
+      *next0 = SRV6_SAMPLE_LOCALSID_NEXT_ERROR;
+      b0->error = node->errors[SRV6_LOCALSID_COUNTER_NO_SRH];
+    }
+  }
+}
+
+/*
+ * @brief SRv6 Sample Localsid graph node
+ * WARNING: YOU MUST DO THE DUAL LOOP
+ */
+static uword
+srv6_localsid_sample_fn (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
+{
+  u32 n_left_from, * from, * to_next;
+  u32 next_index;
+  u32 pkts_swapped = 0;
+  
+  ip6_sr_main_t * sm = &sr_main;
+
+  from = vlib_frame_vector_args (frame);
+  n_left_from = frame->n_vectors;
+  next_index = node->cached_next_index;
+  u32 cpu_index = os_get_cpu_number ();
+
+  while (n_left_from > 0)
+  {
+    u32 n_left_to_next;
+
+    vlib_get_next_frame (vm, node, next_index,
+		   to_next, n_left_to_next);
+
+    while (n_left_from > 0 && n_left_to_next > 0)
+    {
+      u32 bi0;
+      vlib_buffer_t * b0;
+      ip6_header_t * ip0 = 0;
+      ip6_sr_header_t * sr0;
+      u32 next0 = SRV6_SAMPLE_LOCALSID_NEXT_IP6LOOKUP;
+      ip6_sr_localsid_t *ls0;
+      srv6_localsid_sample_per_sid_memory_t *ls0_mem;
+
+      bi0 = from[0];
+      to_next[0] = bi0;
+      from += 1;
+      to_next += 1;
+      n_left_from -= 1;
+      n_left_to_next -= 1;
+
+      b0 = vlib_get_buffer (vm, bi0);
+      ip0 = vlib_buffer_get_current (b0);
+      sr0 = (ip6_sr_header_t *)(ip0+1);
+
+      /* Lookup the SR End behavior based on IP DA (adj) */
+      ls0 = pool_elt_at_index (sm->localsids, vnet_buffer(b0)->ip.adj_index[VLIB_TX]);
+      ls0_mem = ls0->plugin_mem;
+
+      /* SRH processing */
+      end_srh_processing (node, b0, ip0, sr0, &next0);
+
+      /* ==================================================================== */
+      /* INSERT CODE HERE */
+      /* Example starts here */
+      //In this example we are changing the next VRF table by the one in CLI
+      vnet_buffer(b0)->sw_if_index[VLIB_TX] = ls0_mem->fib_table;
+      /* Example finishes here */
+      /* ==================================================================== */
+
+      if (PREDICT_FALSE(b0->flags & VLIB_BUFFER_IS_TRACED)) 
+      {
+        srv6_localsid_sample_trace_t *tr = vlib_add_trace (vm, node, b0, sizeof (*tr));
+        tr->localsid_index = ls0 - sm->localsids;
+      }
+
+      /* This increments the SRv6 per LocalSID counters.*/
+      vlib_increment_combined_counter
+        (((next0 == SRV6_SAMPLE_LOCALSID_NEXT_ERROR) ? &(sm->sr_ls_invalid_counters) : &(sm->sr_ls_valid_counters)),
+        cpu_index,
+        ls0 - sm->localsids,
+        1, vlib_buffer_length_in_chain (vm, b0));
+
+      vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next, 
+        n_left_to_next, bi0, next0);
+
+      pkts_swapped ++;
+    }
+    vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+
+  }
+
+  return frame->n_vectors;
+}
+
+VLIB_REGISTER_NODE (srv6_localsid_sample_node) = {
+  .function = srv6_localsid_sample_fn,
+  .name = "srv6-localsid-sample",
+  .vector_size = sizeof (u32),
+  .format_trace = format_srv6_localsid_sample_trace,
+  .type = VLIB_NODE_TYPE_INTERNAL,
+  .n_errors = SRV6_LOCALSID_N_COUNTERS,
+  .error_strings = srv6_localsid_counter_strings,
+  .n_next_nodes = SRV6_SAMPLE_LOCALSID_N_NEXT,
+  .next_nodes = {
+        [SRV6_SAMPLE_LOCALSID_NEXT_IP6LOOKUP] = "ip6-lookup",
+        [SRV6_SAMPLE_LOCALSID_NEXT_ERROR] = "error-drop",
+    },
+};