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: Wei Wang <weiwan@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h
index 11a79ef..4497a1e 100644
--- a/include/net/ip6_fib.h
+++ b/include/net/ip6_fib.h
@@ -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);
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 837418f..3ccaf52 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -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;
diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index 3afbe50..b3e4cf0 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -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;
}
- return NULL;
+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
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index d2dd55f..855b4ce 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -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;