VPP-166 Documentation changes for ip4_forward.c

[vpp.git] / vnet / vnet / ip / ip4_forward.c

diff --git a/vnet/vnet/ip/ip4_forward.c b/vnet/vnet/ip/ip4_forward.c
index 2ccdd37..4b019bc 100644 (file)
--- a/vnet/vnet/ip/ip4_forward.c
+++ b/vnet/vnet/ip/ip4_forward.c
@@ -39,14 +39,18 @@
 
 #include <vnet/vnet.h>
 #include <vnet/ip/ip.h>
-#include <vnet/ethernet/ethernet.h>    /* for ethernet_header_t */
-#include <vnet/ethernet/arp_packet.h>  /* for ethernet_arp_header_t */
+/** for ethernet_header_t */
+#include <vnet/ethernet/ethernet.h>
+/** for ethernet_arp_header_t */
+#include <vnet/ethernet/arp_packet.h>  
 #include <vnet/ppp/ppp.h>
-#include <vnet/srp/srp.h>      /* for srp_hw_interface_class */
-#include <vnet/api_errno.h>     /* for API error numbers */
+/** for srp_hw_interface_class */
+#include <vnet/srp/srp.h>
+/** for API error numbers */
+#include <vnet/api_errno.h>     
 
-/** \file
-    vnet ip4 forwarding 
+/** @file
+    vnet ip4 forwarding
 */
 
 /* This is really, really simple but stupid fib. */
@@ -75,7 +79,7 @@ ip4_fib_lookup_with_table (ip4_main_t * im, u32 fib_index,
          goto done;
        }
     }
-    
+
   /* Nothing matches in table. */
   ai = lm->miss_adj_index;
 
@@ -83,6 +87,11 @@ ip4_fib_lookup_with_table (ip4_main_t * im, u32 fib_index,
   return ai;
 }
 
+/** @brief Create FIB from table ID and init all hashing.
+    @param im - @ref ip4_main_t
+    @param table_id - table ID
+    @return fib - @ref ip4_fib_t
+*/
 static ip4_fib_t *
 create_fib_with_table_id (ip4_main_t * im, u32 table_id)
 {
@@ -91,6 +100,7 @@ create_fib_with_table_id (ip4_main_t * im, u32 table_id)
   vec_add2 (im->fibs, fib, 1);
   fib->table_id = table_id;
   fib->index = fib - im->fibs;
+  /* IP_FLOW_HASH_DEFAULT is net value of 5 tuple flags without "reverse" bit */
   fib->flow_hash_config = IP_FLOW_HASH_DEFAULT;
   fib->fwd_classify_table_index = ~0;
   fib->rev_classify_table_index = ~0;
@@ -98,28 +108,41 @@ create_fib_with_table_id (ip4_main_t * im, u32 table_id)
   return fib;
 }
 
+/** @brief Find existing or Create new FIB based on index
+    @param im @ref ip4_main_t
+    @param table_index_or_id - overloaded parameter referring
+           to the table or a table's index in the FIB vector
+    @param flags - used to check if table_index_or_id was a table or
+           an index (detected by @ref IP4_ROUTE_FLAG_FIB_INDEX)
+    @return either the existing or a new ip4_fib_t entry
+*/
 ip4_fib_t *
-find_ip4_fib_by_table_index_or_id (ip4_main_t * im, 
+find_ip4_fib_by_table_index_or_id (ip4_main_t * im,
                                    u32 table_index_or_id, u32 flags)
 {
   uword * p, fib_index;
 
   fib_index = table_index_or_id;
+  /* If this isn't a FIB_INDEX ... */
   if (! (flags & IP4_ROUTE_FLAG_FIB_INDEX))
     {
+      /* If passed ~0 then request the next table available */
       if (table_index_or_id == ~0) {
         table_index_or_id = 0;
         while ((p = hash_get (im->fib_index_by_table_id, table_index_or_id))) {
           table_index_or_id++;
         }
-        return create_fib_with_table_id (im, table_index_or_id);
+       /* Create the next table and return the ip4_fib_t associated with it */
+       return create_fib_with_table_id (im, table_index_or_id);
       }
-
+      /* A specific table_id was requested.. */
       p = hash_get (im->fib_index_by_table_id, table_index_or_id);
+      /* ... and if it doesn't exist create it else grab its index */
       if (! p)
        return create_fib_with_table_id (im, table_index_or_id);
       fib_index = p[0];
     }
+  /* Return the ip4_fib_t associated with this index */
   return vec_elt_at_index (im->fibs, fib_index);
 }
 
@@ -193,7 +216,12 @@ ip4_fib_set_adj_index (ip4_main_t * im,
                        fib->new_hash_values);
 
       p = hash_get (hash, dst_address_u32);
-      clib_memcpy (p, fib->new_hash_values, vec_bytes (fib->new_hash_values));
+      /* hash_get should never return NULL here */
+      if (p)
+          clib_memcpy (p, fib->new_hash_values, 
+                       vec_bytes (fib->new_hash_values));
+      else
+          ASSERT(0);
     }
 }
 
@@ -439,7 +467,6 @@ ip4_add_del_route_next_hop (ip4_main_t * im,
     {
       /* create / delete additional mapping of existing adjacency */
       ip4_add_del_route_args_t a;
-      ip_adjacency_t * nh_adj = ip_get_adjacency (lm, nh_adj_index);
 
       a.table_index_or_table_id = fib_index;
       a.flags = ((is_del ? IP4_ROUTE_FLAG_DEL : IP4_ROUTE_FLAG_ADD)
@@ -454,13 +481,6 @@ ip4_add_del_route_next_hop (ip4_main_t * im,
       a.n_add_adj = 0;
 
       ip4_add_del_route (im, &a);
-
-      /* adjust share count. This cannot be the only use of the adjacency 
-         unless next hop is an indiect adj where share count is already
-         incremented */
-      if (next_hop_sw_if_index != ~0) 
-       nh_adj->share_count += is_del ? -1 : 1;
-        
       goto done;
     }
 
@@ -1039,7 +1059,7 @@ ip4_lookup_inline (vlib_main_t * vm,
   return frame->n_vectors;
 }
 
-/** \brief IPv4 lookup node.
+/** @brief IPv4 lookup node.
     @node ip4-lookup
 
     This is the main IPv4 lookup dispatch node.
@@ -1385,6 +1405,13 @@ VNET_IP4_UNICAST_FEATURE_INIT (ip4_source_check_2, static) = {
   &ip4_main.ip4_unicast_rx_feature_source_reachable_via_any,
 };
 
+VNET_IP4_UNICAST_FEATURE_INIT (ip4_source_and_port_range_check, static) = {
+  .node_name = "ip4-source-and-port-range-check",
+  .runs_before = {"ip4-policer-classify", 0},
+  .feature_index =
+  &ip4_main.ip4_unicast_rx_feature_source_and_port_range_check,
+};
+
 VNET_IP4_UNICAST_FEATURE_INIT (ip4_policer_classify, static) = {
   .node_name = "ip4-policer-classify",
   .runs_before = {"ipsec-input-ip4", 0},
@@ -2960,7 +2987,7 @@ ip4_rewrite_inline (vlib_main_t * vm,
 }
 
 
-/** \brief IPv4 transit rewrite node.
+/** @brief IPv4 transit rewrite node.
     @node ip4-rewrite-transit
 
     This is the IPv4 transit-rewrite node: decrement TTL, fix the ipv4
@@ -3000,7 +3027,7 @@ ip4_rewrite_transit (vlib_main_t * vm,
                             /* rewrite_for_locally_received_packets */ 0);
 }
 
-/** \brief IPv4 local rewrite node.
+/** @brief IPv4 local rewrite node.
     @node ip4-rewrite-local
 
     This is the IPv4 local rewrite node. Fetch the ip adjacency, check