Mcast rewrite no memcpy

use a 32bit mask in the adjacency to AND with the IP address and OR into the rewrite.

Change-Id: I80b0f246c18fd74f3e43c5d49e25833412f34665
Signed-off-by: Neale Ranns <nranns@cisco.com>

15 files changed, 93 insertions, 90 deletions

diff --git a/src/vnet/adj/adj.c b/src/vnet/adj/adj.c
index f3d483ac..9a01e89d 100644
--- a/src/vnet/adj/adj.c
+++ b/src/vnet/adj/adj.c
@@ -360,7 +360,7 @@ adj_get_sw_if_index (adj_index_t ai)
 }
 
 /**
- * @brief Return the link type of the adjacency
+ * @brief Return the rewrite string of the adjacency
  */
 const u8*
 adj_get_rewrite (adj_index_t ai)
diff --git a/src/vnet/adj/adj_mcast.c b/src/vnet/adj/adj_mcast.c
index a3ba4d6a..4f678e43 100644
--- a/src/vnet/adj/adj_mcast.c
+++ b/src/vnet/adj/adj_mcast.c
@@ -100,7 +100,9 @@ adj_mcast_add_or_lock (fib_protocol_t proto,
  */
 void
 adj_mcast_update_rewrite (adj_index_t adj_index,
-                          u8 *rewrite)
+                          u8 *rewrite,
+                          u8 offset,
+                          u32 mask)
 {
     ip_adjacency_t *adj;
 
@@ -118,6 +120,13 @@ adj_mcast_update_rewrite (adj_index_t adj_index,
                                         vnet_get_main(),
                                         adj->rewrite_header.sw_if_index),
                                     rewrite);
+    /*
+     * set the fields corresponding to the mcast IP address rewrite
+     * The mask must be stored in network byte order, since the packet's
+     * IP address will also be in network order.
+     */
+    adj->rewrite_header.dst_mcast_offset = offset;
+    adj->rewrite_header.dst_mcast_mask = clib_host_to_net_u32(mask);
 }
 
 void
diff --git a/src/vnet/adj/adj_mcast.h b/src/vnet/adj/adj_mcast.h
index 21c5a141..40d44313 100644
--- a/src/vnet/adj/adj_mcast.h
+++ b/src/vnet/adj/adj_mcast.h
@@ -55,9 +55,18 @@ extern adj_index_t adj_mcast_add_or_lock(fib_protocol_t proto,
  *
  * @param
  *  The new rewrite
+ *
+ * @param
+ *  The offset in the rewrite a which to write in packet's
+ *  IP Address
+ *
+ * @param
+ *  The mask to apply to the packet berfore the rewrite.
  */
 extern void adj_mcast_update_rewrite(adj_index_t adj_index,
-                                     u8 *rewrite);
+                                     u8 *rewrite,
+                                     u8 offset,
+                                     u32 mask);
 
 /**
  * @brief Format/display a mcast adjacency.
diff --git a/src/vnet/ethernet/arp.c b/src/vnet/ethernet/arp.c
index 75c7e203..2f81da32 100644
--- a/src/vnet/ethernet/arp.c
+++ b/src/vnet/ethernet/arp.c
@@ -479,28 +479,30 @@ arp_update_adjacency (vnet_main_t * vnm, u32 sw_if_index, u32 ai)
 	}
       break;
     case IP_LOOKUP_NEXT_MCAST:
-      /*
-       * Construct a partial rewrite from the known ethernet mcast dest MAC
-       */
-      adj_mcast_update_rewrite
-	(ai,
-	 ethernet_build_rewrite (vnm,
-				 sw_if_index,
-				 adj->ia_link,
-				 ethernet_ip4_mcast_dst_addr ()));
-
-      /*
-       * Complete the remaining fields of the adj's rewrite to direct the
-       * complete of the rewrite at switch time by copying in the IP
-       * dst address's bytes.
-       * Ofset is 11 bytes from the end of the MAC header - which is three
-       * bytes into the desintation address. And we write 3 bytes.
-       */
-      adj->rewrite_header.dst_mcast_offset = 11;
-      adj->rewrite_header.dst_mcast_n_bytes = 3;
-
-      break;
+      {
+	/*
+	 * Construct a partial rewrite from the known ethernet mcast dest MAC
+	 */
+	u8 *rewrite;
+	u8 offset;
+
+	rewrite = ethernet_build_rewrite (vnm,
+					  sw_if_index,
+					  adj->ia_link,
+					  ethernet_ip4_mcast_dst_addr ());
+	offset = vec_len (rewrite) - 2;
+
+	/*
+	 * Complete the remaining fields of the adj's rewrite to direct the
+	 * complete of the rewrite at switch time by copying in the IP
+	 * dst address's bytes.
+	 * Ofset is 2 bytes into the MAC desintation address. And we copy 23 bits
+	 * from the address.
+	 */
+	adj_mcast_update_rewrite (ai, rewrite, offset, 0x007fffff);
 
+	break;
+      }
     case IP_LOOKUP_NEXT_DROP:
     case IP_LOOKUP_NEXT_PUNT:
     case IP_LOOKUP_NEXT_LOCAL:
diff --git a/src/vnet/hdlc/hdlc.h b/src/vnet/hdlc/hdlc.h
index 73b15c2f..8407d39d 100644
--- a/src/vnet/hdlc/hdlc.h
+++ b/src/vnet/hdlc/hdlc.h
@@ -91,10 +91,6 @@ hdlc_register_input_type (vlib_main_t * vm,
 			 hdlc_protocol_t protocol,
 			 u32 node_index);
 
-void hdlc_set_adjacency (vnet_rewrite_header_t * rw,
-			uword max_data_bytes,
-			hdlc_protocol_t protocol);
-
 format_function_t format_hdlc_protocol;
 format_function_t format_hdlc_header;
 format_function_t format_hdlc_header_with_length;
diff --git a/src/vnet/ip/ip4_forward.c b/src/vnet/ip/ip4_forward.c
index 7352c2e7..f2bc2a71 100644
--- a/src/vnet/ip/ip4_forward.c
+++ b/src/vnet/ip/ip4_forward.c
@@ -2553,8 +2553,8 @@ ip4_rewrite_inline (vlib_main_t * vm,
 	      /*
 	       * copy bytes from the IP address into the MAC rewrite
 	       */
-	      vnet_fixup_one_header (adj0[0], &ip0->dst_address, ip0, 1);
-	      vnet_fixup_one_header (adj1[0], &ip1->dst_address, ip1, 1);
+	      vnet_fixup_one_header (adj0[0], &ip0->dst_address, ip0);
+	      vnet_fixup_one_header (adj1[0], &ip1->dst_address, ip1);
 	    }
 
 	  vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
@@ -2635,7 +2635,7 @@ ip4_rewrite_inline (vlib_main_t * vm,
 	      /*
 	       * copy bytes from the IP address into the MAC rewrite
 	       */
-	      vnet_fixup_one_header (adj0[0], &ip0->dst_address, ip0, 1);
+	      vnet_fixup_one_header (adj0[0], &ip0->dst_address, ip0);
 	    }
 
 	  /* Update packet buffer attributes/set output interface. */
diff --git a/src/vnet/ip/ip6_forward.c b/src/vnet/ip/ip6_forward.c
index 0b8691bf..ecc3bd2c 100644
--- a/src/vnet/ip/ip6_forward.c
+++ b/src/vnet/ip/ip6_forward.c
@@ -2087,8 +2087,8 @@ ip6_rewrite_inline (vlib_main_t * vm,
 	      /*
 	       * copy bytes from the IP address into the MAC rewrite
 	       */
-	      vnet_fixup_one_header (adj0[0], &ip0->dst_address, ip0, 0);
-	      vnet_fixup_one_header (adj1[0], &ip1->dst_address, ip1, 0);
+	      vnet_fixup_one_header (adj0[0], &ip0->dst_address, ip0);
+	      vnet_fixup_one_header (adj1[0], &ip1->dst_address, ip1);
 	    }
 
 	  vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
@@ -2197,7 +2197,7 @@ ip6_rewrite_inline (vlib_main_t * vm,
 	    }
 	  if (is_mcast)
 	    {
-	      vnet_fixup_one_header (adj0[0], &ip0->dst_address, ip0, 0);
+	      vnet_fixup_one_header (adj0[0], &ip0->dst_address, ip0);
 	    }
 
 	  p0->error = error_node->errors[error0];
diff --git a/src/vnet/ip/ip6_neighbor.c b/src/vnet/ip/ip6_neighbor.c
index 8d355ab2..9b616630 100644
--- a/src/vnet/ip/ip6_neighbor.c
+++ b/src/vnet/ip/ip6_neighbor.c
@@ -530,28 +530,29 @@ ip6_ethernet_update_adjacency (vnet_main_t * vnm, u32 sw_if_index, u32 ai)
 	}
       break;
     case IP_LOOKUP_NEXT_MCAST:
-      /*
-       * Construct a partial rewrite from the known ethernet mcast dest MAC
-       */
-      adj_mcast_update_rewrite
-	(ai,
-	 ethernet_build_rewrite (vnm,
-				 sw_if_index,
-				 adj->ia_link,
-				 ethernet_ip6_mcast_dst_addr ()));
-
-      /*
-       * Complete the remaining fields of the adj's rewrite to direct the
-       * complete of the rewrite at switch time by copying in the IP
-       * dst address's bytes.
-       * Ofset is 12 bytes from the end of the MAC header - which is 2
-       * bytes into the desintation address. And we write 4 bytes.
-       */
-      adj->rewrite_header.dst_mcast_offset = 12;
-      adj->rewrite_header.dst_mcast_n_bytes = 4;
-
-      break;
+      {
+	/*
+	 * Construct a partial rewrite from the known ethernet mcast dest MAC
+	 */
+	u8 *rewrite;
+	u8 offset;
+
+	rewrite = ethernet_build_rewrite (vnm,
+					  sw_if_index,
+					  adj->ia_link,
+					  ethernet_ip6_mcast_dst_addr ());
+
+	/*
+	 * Complete the remaining fields of the adj's rewrite to direct the
+	 * complete of the rewrite at switch time by copying in the IP
+	 * dst address's bytes.
+	 * Ofset is 2 bytes into the desintation address. And we write 4 bytes.
+	 */
+	offset = vec_len (rewrite) - 2;
+	adj_mcast_update_rewrite (ai, rewrite, offset, 0xffffffff);
 
+	break;
+      }
     case IP_LOOKUP_NEXT_DROP:
     case IP_LOOKUP_NEXT_PUNT:
     case IP_LOOKUP_NEXT_LOCAL:
diff --git a/src/vnet/ip/lookup.h b/src/vnet/ip/lookup.h
index 48360b5b..f76ddb37 100644
--- a/src/vnet/ip/lookup.h
+++ b/src/vnet/ip/lookup.h
@@ -55,6 +55,7 @@
 #include <vnet/fib/fib_node.h>
 #include <vnet/dpo/dpo.h>
 #include <vnet/feature/feature.h>
+#include <vnet/rewrite.h>
 
 /** @brief Common (IP4/IP6) next index stored in adjacency. */
 typedef enum
diff --git a/src/vnet/llc/llc.h b/src/vnet/llc/llc.h
index 0b85f5d8..990a581d 100644
--- a/src/vnet/llc/llc.h
+++ b/src/vnet/llc/llc.h
@@ -158,9 +158,6 @@ void
 llc_register_input_protocol (vlib_main_t * vm,
 			     llc_protocol_t protocol, u32 node_index);
 
-void llc_set_adjacency (vnet_rewrite_header_t * rw,
-			uword max_data_bytes, llc_protocol_t protocol);
-
 format_function_t format_llc_protocol;
 format_function_t format_llc_header;
 format_function_t format_llc_header_with_length;
diff --git a/src/vnet/osi/osi.h b/src/vnet/osi/osi.h
index ee21f0c3..0ff267a3 100644
--- a/src/vnet/osi/osi.h
+++ b/src/vnet/osi/osi.h
@@ -131,9 +131,6 @@ extern osi_main_t osi_main;
 /* Register given node index to take input for given osi type. */
 void osi_register_input_protocol (osi_protocol_t protocol, u32 node_index);
 
-void osi_set_adjacency (vnet_rewrite_header_t * rw,
-			uword max_data_bytes, osi_protocol_t protocol);
-
 format_function_t format_osi_protocol;
 format_function_t format_osi_header;
 format_function_t format_osi_header_with_length;
diff --git a/src/vnet/ppp/ppp.h b/src/vnet/ppp/ppp.h
index fdc205b6..726eca66 100644
--- a/src/vnet/ppp/ppp.h
+++ b/src/vnet/ppp/ppp.h
@@ -93,9 +93,6 @@ void
 ppp_register_input_type (vlib_main_t * vm,
 			 ppp_protocol_t protocol, u32 node_index);
 
-void ppp_set_adjacency (vnet_rewrite_header_t * rw,
-			uword max_data_bytes, ppp_protocol_t protocol);
-
 format_function_t format_ppp_protocol;
 format_function_t format_ppp_header;
 format_function_t format_ppp_header_with_length;
diff --git a/src/vnet/rewrite.h b/src/vnet/rewrite.h
index 8435a726..1dea72f5 100644
--- a/src/vnet/rewrite.h
+++ b/src/vnet/rewrite.h
@@ -72,20 +72,18 @@ typedef CLIB_PACKED (struct {
      Used for MTU check after packet rewrite. */
   u16 max_l3_packet_bytes;
 
-  u16 unused1;
-  u8  unused2;
-
+  /* Data-plane flags on the adjacency/rewrite */
   vnet_rewrite_flags_t flags;
 
   /* When dynamically writing a multicast destination L2 addresss
-   * this is the offset within the address to start writing n
-   * bytes of the IP mcast address */
+   * this is the offset from the IP address at which to write in the
+   * IP->MAC address translation.
+   */
   u8 dst_mcast_offset;
 
-  /* When dynamically writing a multicast destination L2 addresss
-   * this is the number of bytes of the dest IP address to write into
-   * the MAC rewrite */
-  u8 dst_mcast_n_bytes;
+  /* The mask to apply to the lower 4 bytes of the IP address before ORing
+   * into the destinaiton MAC address */
+  u32 dst_mcast_mask;
 
   /* Rewrite string starting at end and going backwards. */
   u8 data[0];
@@ -293,24 +291,24 @@ _vnet_rewrite_two_headers (vnet_rewrite_header_t * h0,
 
 always_inline void
 _vnet_fixup_one_header (vnet_rewrite_header_t * h0,
-			u8 * addr, u32 addr_len,
-			u8 * packet0, int clear_first_bit)
+			u8 * addr, u32 addr_len, u8 * packet0)
 {
-  /* location to write to in the packet */
-  u8 *p0 = packet0 - h0->dst_mcast_offset;
-  u8 *p1 = p0;
-  /* location to write from in the L3 dest address */
-  u8 *a0 = addr + addr_len - h0->dst_mcast_n_bytes;
-
-  clib_memcpy (p0, a0, h0->dst_mcast_n_bytes);
-  if (clear_first_bit)
-    *p1 &= 0x7f;
+  if (PREDICT_TRUE (h0->dst_mcast_mask))
+    {
+      /* location to write to in the packet */
+      u8 *p0 = packet0 - h0->dst_mcast_offset;
+      u32 *p1 = (u32 *) p0;
+      /* location to copy from in the L3 dest address */
+      u32 *a0 = (u32 *) (addr + addr_len - sizeof (h0->dst_mcast_mask));
+
+      *p1 |= (*a0 & h0->dst_mcast_mask);
+    }
 }
 
-#define vnet_fixup_one_header(rw0,addr,p0,clear_first_bit)              \
+#define vnet_fixup_one_header(rw0,addr,p0)              \
   _vnet_fixup_one_header (&((rw0).rewrite_header),                      \
                           (u8*)(addr), sizeof((*addr)),                 \
-                          (u8*)(p0), (clear_first_bit))
+                          (u8*)(p0))
 
 #define VNET_REWRITE_FOR_SW_INTERFACE_ADDRESS_BROADCAST ((void *) 0)
 /** Deprecated */
diff --git a/src/vnet/snap/snap.h b/src/vnet/snap/snap.h
index dbba15bf..7cd453e7 100644
--- a/src/vnet/snap/snap.h
+++ b/src/vnet/snap/snap.h
@@ -173,9 +173,6 @@ snap_register_input_protocol (vlib_main_t * vm,
 			      char *name,
 			      u32 ieee_oui, u16 protocol, u32 node_index);
 
-void snap_set_adjacency (vnet_rewrite_header_t * rw,
-			 uword max_data_bytes, u32 ieee_oui, u16 protocol);
-
 format_function_t format_snap_protocol;
 format_function_t format_snap_header;
 format_function_t format_snap_header_with_length;
diff --git a/src/vnet/vnet.h b/src/vnet/vnet.h
index 5a8ae858..8405f61b 100644
--- a/src/vnet/vnet.h
+++ b/src/vnet/vnet.h
@@ -46,7 +46,6 @@
 #include <vnet/buffer.h>
 #include <vnet/config.h>
 #include <vnet/interface.h>
-#include <vnet/rewrite.h>
 #include <vnet/api_errno.h>
 
 typedef struct vnet_main_t