Commit 862a03c3 authored by William Tu's avatar William Tu Committed by David S. Miller
Browse files

gre: refactor the gre_fb_xmit 



The patch refactors the gre_fb_xmit function, by creating
prepare_fb_xmit function for later ERSPAN collect_md mode patch.

Signed-off-by: default avatarWilliam Tu <u9012063@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 03157937

net/ipv4/ip_gre.c

+40 −15
Original line number Diff line number Diff line
@@ -432,39 +432,33 @@ static struct rtable *gre_get_rt(struct sk_buff *skb, 
	return ip_route_output_key(net, fl);

}



static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev,

			__be16 proto)

static struct rtable *prepare_fb_xmit(struct sk_buff *skb,

				      struct net_device *dev,

				      struct flowi4 *fl,

				      int tunnel_hlen)

{

	struct ip_tunnel_info *tun_info;

	const struct ip_tunnel_key *key;

	struct rtable *rt = NULL;

	struct flowi4 fl;

	int min_headroom;

	int tunnel_hlen;

	__be16 df, flags;

	bool use_cache;

	int err;



	tun_info = skb_tunnel_info(skb);

	if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||

		     ip_tunnel_info_af(tun_info) != AF_INET))

		goto err_free_skb;



	key = &tun_info->key;

	use_cache = ip_tunnel_dst_cache_usable(skb, tun_info);



	if (use_cache)

		rt = dst_cache_get_ip4(&tun_info->dst_cache, &fl.saddr);

		rt = dst_cache_get_ip4(&tun_info->dst_cache, &fl->saddr);

	if (!rt) {

		rt = gre_get_rt(skb, dev, &fl, key);

		rt = gre_get_rt(skb, dev, fl, key);

		if (IS_ERR(rt))

			goto err_free_skb;

		if (use_cache)

			dst_cache_set_ip4(&tun_info->dst_cache, &rt->dst,

					  fl.saddr);

					  fl->saddr);

	}



	tunnel_hlen = gre_calc_hlen(key->tun_flags);



	min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len

			+ tunnel_hlen + sizeof(struct iphdr);

	if (skb_headroom(skb) < min_headroom || skb_header_cloned(skb)) {
@@ -476,6 +470,37 @@ static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev, 
		if (unlikely(err))

			goto err_free_rt;

	}

	return rt;



err_free_rt:

	ip_rt_put(rt);

err_free_skb:

	kfree_skb(skb);

	dev->stats.tx_dropped++;

	return NULL;

}



static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev,

			__be16 proto)

{

	struct ip_tunnel_info *tun_info;

	const struct ip_tunnel_key *key;

	struct rtable *rt = NULL;

	struct flowi4 fl;

	int tunnel_hlen;

	__be16 df, flags;



	tun_info = skb_tunnel_info(skb);

	if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||

		     ip_tunnel_info_af(tun_info) != AF_INET))

		goto err_free_skb;



	key = &tun_info->key;

	tunnel_hlen = gre_calc_hlen(key->tun_flags);



	rt = prepare_fb_xmit(skb, dev, &fl, tunnel_hlen);

	if (!rt)

		return;



	/* Push Tunnel header. */

	if (gre_handle_offloads(skb, !!(tun_info->key.tun_flags & TUNNEL_CSUM)))