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ipv6: prepare fib6_locate() for exception table

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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>
This commit is contained in:
Wei Wang 2017-10-06 12:06:02 -07:00 committed by David S. Miller
parent c757faa8bf
commit 38fbeeeecc
4 changed files with 29 additions and 11 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

3
include/net/ip6_fib.h
View file

@ -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);

2
net/ipv6/addrconf.c
View file

@ -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;

30
net/ipv6/ip6_fib.c
View file

@ -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

5
net/ipv6/route.c
View file

@ -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;