2007-01-06 02:30:29

by Chris Wright

[permalink] [raw]
Subject: [patch 23/50] UDP: Fix reversed logic in udp_get_port()

-stable review patch. If anyone has any objections, please let us know.
------------------

From: David Miller <[email protected]>

When this code was converted to use sk_for_each() the
logic for the "best hash chain length" code was reversed,
breaking everything.

The original code was of the form:

size = 0;
do {
if (++size >= best_size_so_far)
goto next;
} while ((sk = sk->next) != NULL);
best_size_so_far = size;
best = result;
next:;

and this got converted into:

sk_for_each(sk2, node, head)
if (++size < best_size_so_far) {
best_size_so_far = size;
best = result;
}

Which does something very very different from the original.

Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Chris Wright <[email protected]>
---
net/ipv4/udp.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)

--- linux-2.6.19.1.orig/net/ipv4/udp.c
+++ linux-2.6.19.1/net/ipv4/udp.c
@@ -167,11 +167,14 @@ int udp_get_port(struct sock *sk, unsign
goto gotit;
}
size = 0;
- sk_for_each(sk2, node, head)
- if (++size < best_size_so_far) {
- best_size_so_far = size;
- best = result;
- }
+ sk_for_each(sk2, node, head) {
+ if (++size >= best_size_so_far)
+ goto next;
+ }
+ best_size_so_far = size;
+ best = result;
+ next:
+ ;
}
result = best;
for(i = 0; i < (1 << 16) / UDP_HTABLE_SIZE; i++, result += UDP_HTABLE_SIZE) {

--