tipc: improve and extend media address conversion functions

TIPC currently handles two media specific addresses: Ethernet MAC
addresses and InfiniBand addresses. Those are kept in three different
formats:

1) A "raw" format as obtained from the device. This format is known
   only by the media specific adapter code in eth_media.c and
   ib_media.c.
2) A "generic" internal format, in the form of struct tipc_media_addr,
   which can be referenced and passed around by the generic media-
   unaware code.
3) A serialized version of the latter, to be conveyed in neighbor
   discovery messages.

Conversion between the three formats can only be done by the media
specific code, so we have function pointers for this purpose in
struct tipc_media. Here, the media adapters can install their own
conversion functions at startup.

We now introduce a new such function, 'raw2addr()', whose purpose
is to convert from format 1 to format 2 above. We also try to as far
as possible uniform commenting, variable names and usage of these
functions, with the purpose of making them more comprehensible.

We can now also remove the function tipc_l2_media_addr_set(), whose
job is done better by the new function.

Finally, we expand the field for serialized addresses (format 3)
in discovery messages from 20 to 32 bytes. This is permitted
according to the spec, and reduces the risk of problems when we
add new media in the future.

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 29 deletions

diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c
index f3259d4133b6..264474394f9f 100644
--- a/net/tipc/bearer.c
+++ b/net/tipc/bearer.c
@@ -411,28 +411,6 @@ int tipc_disable_bearer(const char *name)
 	return res;
 }
 
-
-/* tipc_l2_media_addr_set - initialize Ethernet media address structure
- *
- * Media-dependent "value" field stores MAC address in first 6 bytes
- * and zeroes out the remaining bytes.
- */
-void tipc_l2_media_addr_set(const struct tipc_bearer *b,
-			    struct tipc_media_addr *a, char *mac)
-{
-	int len = b->media->hwaddr_len;
-
-	if (unlikely(sizeof(a->value) < len)) {
-		WARN_ONCE(1, "Media length invalid\n");
-		return;
-	}
-
-	memcpy(a->value, mac, len);
-	memset(a->value + len, 0, sizeof(a->value) - len);
-	a->media_id = b->media->type_id;
-	a->broadcast = !memcmp(mac, b->bcast_addr.value, len);
-}
-
 int tipc_enable_l2_media(struct tipc_bearer *b)
 {
 	struct net_device *dev;
@@ -443,21 +421,21 @@ int tipc_enable_l2_media(struct tipc_bearer *b)
 	if (!dev)
 		return -ENODEV;
 
-	/* Associate TIPC bearer with Ethernet bearer */
+	/* Associate TIPC bearer with L2 bearer */
 	rcu_assign_pointer(b->media_ptr, dev);
-	memset(b->bcast_addr.value, 0, sizeof(b->bcast_addr.value));
+	memset(&b->bcast_addr, 0, sizeof(b->bcast_addr));
 	memcpy(b->bcast_addr.value, dev->broadcast, b->media->hwaddr_len);
 	b->bcast_addr.media_id = b->media->type_id;
 	b->bcast_addr.broadcast = 1;
 	b->mtu = dev->mtu;
-	tipc_l2_media_addr_set(b, &b->addr, (char *)dev->dev_addr);
+	b->media->raw2addr(b, &b->addr, (char *)dev->dev_addr);
 	rcu_assign_pointer(dev->tipc_ptr, b);
 	return 0;
 }
 
-/* tipc_disable_l2_media - detach TIPC bearer from an Ethernet interface
+/* tipc_disable_l2_media - detach TIPC bearer from an L2 interface
  *
- * Mark Ethernet bearer as inactive so that incoming buffers are thrown away,
+ * Mark L2 bearer as inactive so that incoming buffers are thrown away,
  * then get worker thread to complete bearer cleanup.  (Can't do cleanup
  * here because cleanup code needs to sleep and caller holds spinlocks.)
  */
@@ -473,7 +451,7 @@ void tipc_disable_l2_media(struct tipc_bearer *b)
 }
 
 /**
- * tipc_l2_send_msg - send a TIPC packet out over an Ethernet interface
+ * tipc_l2_send_msg - send a TIPC packet out over an L2 interface
  * @buf: the packet to be sent
  * @b_ptr: the bearer through which the packet is to be sent
  * @dest: peer destination address
@@ -597,7 +575,7 @@ static int tipc_l2_device_event(struct notifier_block *nb, unsigned long evt,
 		tipc_reset_bearer(b_ptr);
 		break;
 	case NETDEV_CHANGEADDR:
-		tipc_l2_media_addr_set(b_ptr, &b_ptr->addr,
+		b_ptr->media->raw2addr(b_ptr, &b_ptr->addr,
 				       (char *)dev->dev_addr);
 		tipc_reset_bearer(b_ptr);
 		break;