Commit 6640e697 authored Jan 24, 2007 by Eric W. Biederman Committed by David S. Miller Jan 24, 2007

[IPV4]: Fix the fib trie iterator to work with a single entry routing tables



In a kernel with trie routing enabled I had a simple routing setup
with only a single route to the outside world and no default
route. "ip route table list main" showed my the route just fine but
/proc/net/route was an empty file.  What was going on?

Thinking it was a bug in something I did and I looked deeper.  Eventually
I setup a second route and everything looked correct, huh?  Finally I
realized that the it was just the iterator pair in fib_trie_get_first,
fib_trie_get_next just could not handle a routing table with a single entry.

So to save myself and others further confusion, here is a simple fix for
the fib proc iterator so it works even when there is only a single route
in a routing table.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Robert Olsson <robert.olsson@its.uu.se>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent a21b0696

net/ipv4/fib_trie.c

+16 −5

Original line number	Diff line number	Diff line
		@@ -1989,6 +1989,10 @@ static struct node fib_trie_get_next(struct fib_trie_iter iter)
		unsigned cindex = iter->index;
		struct tnode *p;

		/* A single entry routing table */
		if (!tn)
		return NULL;

		pr_debug("get_next iter={node=%p index=%d depth=%d}\n",
		iter->tnode, iter->index, iter->depth);
		rescan:
		@@ -2037,11 +2041,18 @@ static struct node fib_trie_get_first(struct fib_trie_iter iter,
		if(!iter)
		return NULL;

		if (n && IS_TNODE(n)) {
		if (n) {
		if (IS_TNODE(n)) {
		iter->tnode = (struct tnode *) n;
		iter->trie = t;
		iter->index = 0;
		iter->depth = 1;
		} else {
		iter->tnode = NULL;
		iter->trie = t;
		iter->index = 0;
		iter->depth = 0;
		}
		return n;
		}
		return NULL;