Commit 38fbeeee authored by Wei Wang's avatar Wei Wang Committed by David S. Miller
Browse files

ipv6: prepare fib6_locate() for exception table 



fib6_locate() is used to find the fib6_node according to the passed in
prefix address key. It currently tries to find the fib6_node with the
exact match of the passed in key. However, when we move cached routes
into the exception table, fib6_locate() will fail to find the fib6_node
for it as the cached routes will be stored in the exception table under
the fib6_node with the longest prefix match of the cache's dst addr key.
This commit adds a new parameter to let the caller specify if it needs
exact match or longest prefix match.
Right now, all callers still does exact match when calling
fib6_locate(). It will be changed in later commit where exception table
is hooked up to store cached routes.

Signed-off-by: default avatarWei Wang <weiwan@google.com>
Signed-off-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c757faa8

include/net/ip6_fib.h

+2 −1
Original line number Diff line number Diff line
@@ -357,7 +357,8 @@ struct fib6_node *fib6_lookup(struct fib6_node *root, 


struct fib6_node *fib6_locate(struct fib6_node *root,

			      const struct in6_addr *daddr, int dst_len,

			      const struct in6_addr *saddr, int src_len);

			      const struct in6_addr *saddr, int src_len,

			      bool exact_match);



void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *arg),

		    void *arg);

net/ipv6/addrconf.c

+1 −1
Original line number Diff line number Diff line
@@ -2322,7 +2322,7 @@ static struct rt6_info *addrconf_get_prefix_route(const struct in6_addr *pfx, 
		return NULL;



	read_lock_bh(&table->tb6_lock);

	fn = fib6_locate(&table->tb6_root, pfx, plen, NULL, 0);

	fn = fib6_locate(&table->tb6_root, pfx, plen, NULL, 0, true);

	if (!fn)

		goto out;

net/ipv6/ip6_fib.c

+23 −7
Original line number Diff line number Diff line
@@ -1343,14 +1343,21 @@ struct fib6_node *fib6_lookup(struct fib6_node *root, const struct in6_addr *dad 
/*

 *	Get node with specified destination prefix (and source prefix,

 *	if subtrees are used)

 *	exact_match == true means we try to find fn with exact match of

 *	the passed in prefix addr

 *	exact_match == false means we try to find fn with longest prefix

 *	match of the passed in prefix addr. This is useful for finding fn

 *	for cached route as it will be stored in the exception table under

 *	the node with longest prefix length.

 */





static struct fib6_node *fib6_locate_1(struct fib6_node *root,

				       const struct in6_addr *addr,

				       int plen, int offset)

				       int plen, int offset,

				       bool exact_match)

{

	struct fib6_node *fn;

	struct fib6_node *fn, *prev = NULL;



	for (fn = root; fn ; ) {

		struct rt6key *key = (struct rt6key *)((u8 *)fn->leaf + offset);
@@ -1360,11 +1367,13 @@ static struct fib6_node *fib6_locate_1(struct fib6_node *root, 
		 */

		if (plen < fn->fn_bit ||

		    !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit))

			return NULL;

			goto out;



		if (plen == fn->fn_bit)

			return fn;



		prev = fn;



		/*

		 *	We have more bits to go

		 */
@@ -1373,24 +1382,31 @@ static struct fib6_node *fib6_locate_1(struct fib6_node *root, 
		else

			fn = fn->left;

	}

out:

	if (exact_match)

		return NULL;

	else

		return prev;

}



struct fib6_node *fib6_locate(struct fib6_node *root,

			      const struct in6_addr *daddr, int dst_len,

			      const struct in6_addr *saddr, int src_len)

			      const struct in6_addr *saddr, int src_len,

			      bool exact_match)

{

	struct fib6_node *fn;



	fn = fib6_locate_1(root, daddr, dst_len,

			   offsetof(struct rt6_info, rt6i_dst));

			   offsetof(struct rt6_info, rt6i_dst),

			   exact_match);



#ifdef CONFIG_IPV6_SUBTREES

	if (src_len) {

		WARN_ON(saddr == NULL);

		if (fn && fn->subtree)

			fn = fib6_locate_1(fn->subtree, saddr, src_len,

					   offsetof(struct rt6_info, rt6i_src));

					   offsetof(struct rt6_info, rt6i_src),

					   exact_match);

	}

#endif

net/ipv6/route.c

+3 −2
Original line number Diff line number Diff line
@@ -2800,7 +2800,8 @@ static int ip6_route_del(struct fib6_config *cfg, 


	fn = fib6_locate(&table->tb6_root,

			 &cfg->fc_dst, cfg->fc_dst_len,

			 &cfg->fc_src, cfg->fc_src_len);

			 &cfg->fc_src, cfg->fc_src_len,

			 true);



	if (fn) {

		for (rt = fn->leaf; rt; rt = rt->dst.rt6_next) {
@@ -3009,7 +3010,7 @@ static struct rt6_info *rt6_get_route_info(struct net *net, 
		return NULL;



	read_lock_bh(&table->tb6_lock);

	fn = fib6_locate(&table->tb6_root, prefix, prefixlen, NULL, 0);

	fn = fib6_locate(&table->tb6_root, prefix, prefixlen, NULL, 0, true);

	if (!fn)

		goto out;

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