[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>
diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index cfb249c..13307c0 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -1989,6 +1989,10 @@
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 @@
if(!iter)
return NULL;
- if (n && IS_TNODE(n)) {
- iter->tnode = (struct tnode *) n;
- iter->trie = t;
- iter->index = 0;
- iter->depth = 1;
+ 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;
