Commit 936f6f8e authored by Julian Anastasov's avatar Julian Anastasov Committed by David S. Miller
Browse files

[IPV4] fib_trie: apply fixes from fib_hash 



	Update fib_trie with some fib_hash fixes:
- check for duplicate alternative routes for prefix+tos+priority when
replacing route
- properly insert by matching tos together with priority
- fix alias walking to use list_for_each_entry_continue for insertion
and deletion when fa_head is not NULL
- copy state from fa to new_fa on replace (not a problem for now)
- additionally, avoid replacement without error if new route is same,
as Joonwoo Park suggests.

Signed-off-by: default avatarJulian Anastasov <ja@ssi.bg>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c18865f3

net/ipv4/fib_trie.c

+35 −20
Original line number Diff line number Diff line
@@ -1205,20 +1205,45 @@ static int fn_trie_insert(struct fib_table *tb, struct fib_config *cfg) 
	 * and we need to allocate a new one of those as well.

	 */



	if (fa && fa->fa_info->fib_priority == fi->fib_priority) {

		struct fib_alias *fa_orig;

	if (fa && fa->fa_tos == tos &&

	    fa->fa_info->fib_priority == fi->fib_priority) {

		struct fib_alias *fa_first, *fa_match;



		err = -EEXIST;

		if (cfg->fc_nlflags & NLM_F_EXCL)

			goto out;



		/* We have 2 goals:

		 * 1. Find exact match for type, scope, fib_info to avoid

		 * duplicate routes

		 * 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it

		 */

		fa_match = NULL;

		fa_first = fa;

		fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);

		list_for_each_entry_continue(fa, fa_head, fa_list) {

			if (fa->fa_tos != tos)

				break;

			if (fa->fa_info->fib_priority != fi->fib_priority)

				break;

			if (fa->fa_type == cfg->fc_type &&

			    fa->fa_scope == cfg->fc_scope &&

			    fa->fa_info == fi) {

				fa_match = fa;

				break;

			}

		}



		if (cfg->fc_nlflags & NLM_F_REPLACE) {

			struct fib_info *fi_drop;

			u8 state;



			if (fi->fib_treeref > 1)

			fa = fa_first;

			if (fa_match) {

				if (fa == fa_match)

					err = 0;

				goto out;



			}

			err = -ENOBUFS;

			new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);

			if (new_fa == NULL)
@@ -1230,7 +1255,7 @@ static int fn_trie_insert(struct fib_table *tb, struct fib_config *cfg) 
			new_fa->fa_type = cfg->fc_type;

			new_fa->fa_scope = cfg->fc_scope;

			state = fa->fa_state;

			new_fa->fa_state &= ~FA_S_ACCESSED;

			new_fa->fa_state = state & ~FA_S_ACCESSED;



			list_replace_rcu(&fa->fa_list, &new_fa->fa_list);

			alias_free_mem_rcu(fa);
@@ -1247,20 +1272,11 @@ static int fn_trie_insert(struct fib_table *tb, struct fib_config *cfg) 
		 * uses the same scope, type, and nexthop

		 * information.

		 */

		fa_orig = fa;

		list_for_each_entry(fa, fa_orig->fa_list.prev, fa_list) {

			if (fa->fa_tos != tos)

				break;

			if (fa->fa_info->fib_priority != fi->fib_priority)

				break;

			if (fa->fa_type == cfg->fc_type &&

			    fa->fa_scope == cfg->fc_scope &&

			    fa->fa_info == fi)

		if (fa_match)

			goto out;

		}



		if (!(cfg->fc_nlflags & NLM_F_APPEND))

			fa = fa_orig;

			fa = fa_first;

	}

	err = -ENOENT;

	if (!(cfg->fc_nlflags & NLM_F_CREATE))
@@ -1600,9 +1616,8 @@ static int fn_trie_delete(struct fib_table *tb, struct fib_config *cfg) 
	pr_debug("Deleting %08x/%d tos=%d t=%p\n", key, plen, tos, t);



	fa_to_delete = NULL;

	fa_head = fa->fa_list.prev;



	list_for_each_entry(fa, fa_head, fa_list) {

	fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);

	list_for_each_entry_continue(fa, fa_head, fa_list) {

		struct fib_info *fi = fa->fa_info;



		if (fa->fa_tos != tos)

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