packets: Adds ethernet-matching helper functions

With OpenFlow 1.1 requiring arbitrary ethernet match support, it simplifies
other code if we have some extra helper functions. This patch adds
eth_mask_is_exact(mask), eth_addr_bitand(src, mask, dst),
eth_addr_equal_except(a, b, mask) and eth_format_masked(eth, mask, output).

Signed-off-by: Joe Stringer <joe@wand.net.nz>
Signed-off-by: Ben Pfaff <blp@nicira.com>

diff --git a/AUTHORS b/AUTHORS
index 6e344ab013624e40aa82f37331392d085cfdea0a..2ea91109c08073cedb0436869238e49eb54f685d 100644 (file)
--- a/AUTHORS
+++ b/AUTHORS
@@ -33,6 +33,7 @@ Jean Tourrilhes         jt@hpl.hp.com
 Jeremy Stribling        strib@nicira.com
 Jesse Gross             jesse@nicira.com
 Joe Perches             joe@perches.com
+Joe Stringer            joe@wand.net.nz
 Jun Nakajima            jun.nakajima@intel.com
 Justin Pettit           jpettit@nicira.com
 Keith Amidon            keith@nicira.com

diff --git a/lib/meta-flow.c b/lib/meta-flow.c
index 8b60b35f11ee0368b5b7b129ab618f0cdff508b2..9387d3a4194d59b5cf8a0d1c32c3bdaa3c329d7d 100644 (file)
--- a/lib/meta-flow.c
+++ b/lib/meta-flow.c
@@ -2273,10 +2273,7 @@ mf_format(const struct mf_field *mf,
         break;
 
     case MFS_ETHERNET:
-        ds_put_format(s, ETH_ADDR_FMT, ETH_ADDR_ARGS(value->mac));
-        if (mask) {
-            ds_put_format(s, "/"ETH_ADDR_FMT, ETH_ADDR_ARGS(mask->mac));
-        }
+        eth_format_masked(value->mac, mask->mac, s);
         break;
 
     case MFS_IPV4:

diff --git a/lib/packets.c b/lib/packets.c
index 84ca590bda90d23af12b1f8a9d82f2813728faa1..b3851280a31f1a64ea05749af501b9c11c6fb4b7 100644 (file)
--- a/lib/packets.c
+++ b/lib/packets.c
@@ -148,6 +148,28 @@ eth_from_hex(const char *hex, struct ofpbuf **packetp)
     return NULL;
 }
 
+void
+eth_format_masked(const uint8_t eth[ETH_ADDR_LEN],
+                  const uint8_t mask[ETH_ADDR_LEN], struct ds *s)
+{
+    ds_put_format(s, ETH_ADDR_FMT, ETH_ADDR_ARGS(eth));
+    if (mask) {
+        ds_put_format(s, "/"ETH_ADDR_FMT, ETH_ADDR_ARGS(mask));
+    }
+}
+
+void
+eth_addr_bitand(const uint8_t src[ETH_ADDR_LEN],
+                const uint8_t mask[ETH_ADDR_LEN],
+                uint8_t dst[ETH_ADDR_LEN])
+{
+    int i;
+
+    for (i = 0; i < ETH_ADDR_LEN; i++) {
+        dst[i] = src[i] & mask[i];
+    }
+}
+
 /* Given the IP netmask 'netmask', returns the number of bits of the IP address
  * that it specifies, that is, the number of 1-bits in 'netmask'.  'netmask'
  * must be a CIDR netmask (see ip_is_cidr()). */

diff --git a/lib/packets.h b/lib/packets.h
index f9e5bb6cef61ef44e6f63d68d356df238611be37..00c2b75bf13fde9602ffecdabb244bedee73985a 100644 (file)
--- a/lib/packets.h
+++ b/lib/packets.h
@@ -64,6 +64,12 @@ static inline bool eth_addr_is_zero(const uint8_t ea[6])
 {
     return !(ea[0] | ea[1] | ea[2] | ea[3] | ea[4] | ea[5]);
 }
+
+static inline int eth_mask_is_exact(const uint8_t ea[ETH_ADDR_LEN])
+{
+    return (ea[0] & ea[1] & ea[2] & ea[3] & ea[4] & ea[5]) == 0xff;
+}
+
 static inline int eth_addr_compare_3way(const uint8_t a[ETH_ADDR_LEN],
                                         const uint8_t b[ETH_ADDR_LEN])
 {
@@ -74,6 +80,17 @@ static inline bool eth_addr_equals(const uint8_t a[ETH_ADDR_LEN],
 {
     return !eth_addr_compare_3way(a, b);
 }
+static inline bool eth_addr_equal_except(const uint8_t a[ETH_ADDR_LEN],
+                                    const uint8_t b[ETH_ADDR_LEN],
+                                    const uint8_t mask[ETH_ADDR_LEN])
+{
+    return (((a[0] ^ b[0]) & mask[0])
+            || ((a[1] ^ b[1]) & mask[1])
+            || ((a[2] ^ b[2]) & mask[2])
+            || ((a[3] ^ b[3]) & mask[3])
+            || ((a[4] ^ b[4]) & mask[4])
+            || ((a[5] ^ b[5]) & mask[5]));
+}
 static inline uint64_t eth_addr_to_uint64(const uint8_t ea[ETH_ADDR_LEN])
 {
     return (((uint64_t) ea[0] << 40)
@@ -136,6 +153,11 @@ void eth_push_vlan(struct ofpbuf *, ovs_be16 tci);
 void eth_pop_vlan(struct ofpbuf *);
 
 const char *eth_from_hex(const char *hex, struct ofpbuf **packetp);
+void eth_format_masked(const uint8_t eth[ETH_ADDR_LEN],
+                       const uint8_t mask[ETH_ADDR_LEN], struct ds *s);
+void eth_addr_bitand(const uint8_t src[ETH_ADDR_LEN],
+                     const uint8_t mask[ETH_ADDR_LEN],
+                     uint8_t dst[ETH_ADDR_LEN]);
 
 /* Example:
  *