tipc: eliminate code duplication in media layer

Currently TIPC supports two L2 media types, Ethernet and Infiniband.
Because both these media are accessed through the common net_device API,
several functions in the two media adaptation files turn out to be
fully or almost identical, leading to unnecessary code duplication.

In this commit we extract this common code from the two media files
and move them to the generic bearer.c. Additionally, we change
the function names to reflect their real role: to access L2 media,
irrespective of type.

Signed-off-by: Ying Xue <ying.xue@windriver.com>
Cc: Patrick McHardy <kaber@trash.net>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 104 insertions, 2 deletions

diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c
index e95e0b9..3bb5f26 100644
--- a/net/tipc/bearer.c
+++ b/net/tipc/bearer.c
@@ -2,7 +2,7 @@
  * net/tipc/bearer.c: TIPC bearer code
  *
  * Copyright (c) 1996-2006, 2013, Ericsson AB
- * Copyright (c) 2004-2006, 2010-2011, Wind River Systems
+ * Copyright (c) 2004-2006, 2010-2013, Wind River Systems
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -332,6 +332,7 @@ restart:
 
 	b_ptr = &tipc_bearers[bearer_id];
 	strcpy(b_ptr->name, name);
+	b_ptr->media = m_ptr;
 	res = m_ptr->enable_media(b_ptr);
 	if (res) {
 		pr_warn("Bearer <%s> rejected, enable failure (%d)\n",
@@ -340,7 +341,6 @@ restart:
 	}
 
 	b_ptr->identity = bearer_id;
-	b_ptr->media = m_ptr;
 	b_ptr->tolerance = m_ptr->tolerance;
 	b_ptr->window = m_ptr->window;
 	b_ptr->net_plane = bearer_id + 'A';
@@ -432,6 +432,108 @@ 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;
+	char *driver_name = strchr((const char *)b->name, ':') + 1;
+
+	/* Find device with specified name */
+	dev = dev_get_by_name(&init_net, driver_name);
+	if (!dev)
+		return -ENODEV;
+
+	/* Associate TIPC bearer with Ethernet bearer */
+	b->media_ptr = dev;
+	memset(b->bcast_addr.value, 0, sizeof(b->bcast_addr.value));
+	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);
+	rcu_assign_pointer(dev->tipc_ptr, b);
+	return 0;
+}
+
+/* tipc_disable_l2_media - detach TIPC bearer from an Ethernet interface
+ *
+ * Mark Ethernet 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.)
+ */
+void tipc_disable_l2_media(struct tipc_bearer *b)
+{
+	struct net_device *dev = (struct net_device *)b->media_ptr;
+	RCU_INIT_POINTER(dev->tipc_ptr, NULL);
+	dev_put(dev);
+}
+
+/**
+ * tipc_l2_send_msg - send a TIPC packet out over an Ethernet interface
+ * @buf: the packet to be sent
+ * @b_ptr: the bearer throught which the packet is to be sent
+ * @dest: peer destination address
+ */
+int tipc_l2_send_msg(struct sk_buff *buf, struct tipc_bearer *b,
+		     struct tipc_media_addr *dest)
+{
+	struct sk_buff *clone;
+	int delta;
+	struct net_device *dev = (struct net_device *)b->media_ptr;
+
+	clone = skb_clone(buf, GFP_ATOMIC);
+	if (!clone)
+		return 0;
+
+	delta = dev->hard_header_len - skb_headroom(buf);
+	if ((delta > 0) &&
+	    pskb_expand_head(clone, SKB_DATA_ALIGN(delta), 0, GFP_ATOMIC)) {
+		kfree_skb(clone);
+		return 0;
+	}
+
+	skb_reset_network_header(clone);
+	clone->dev = dev;
+	clone->protocol = htons(ETH_P_TIPC);
+	dev_hard_header(clone, dev, ETH_P_TIPC, dest->value,
+			dev->dev_addr, clone->len);
+	dev_queue_xmit(clone);
+	return 0;
+}
+
+/* tipc_bearer_send- sends buffer to destination over bearer
+ *
+ * IMPORTANT:
+ * The media send routine must not alter the buffer being passed in
+ * as it may be needed for later retransmission!
+ */
+void tipc_bearer_send(struct tipc_bearer *b, struct sk_buff *buf,
+		      struct tipc_media_addr *dest)
+{
+	b->media->send_msg(buf, b, dest);
+}
+
 /**
  * tipc_l2_rcv_msg - handle incoming TIPC message from an interface
  * @buf: the received packet