path: root/include
diff options
authorEric Dumazet <eric.dumazet@gmail.com>2010-09-08 05:08:44 +0000
committerDavid S. Miller <davem@davemloft.net>2010-09-08 21:45:01 -0700
commit719f835853a92f6090258114a72ffe41f09155cd (patch)
treea077b05397bf07a096be7f07b50375c5ed918ac2 /include
parentae2688d59b5f861dc70a091d003773975d2ae7fb (diff)
udp: add rehash on connect()
commit 30fff923 introduced in linux-2.6.33 (udp: bind() optimisation) added a secondary hash on UDP, hashed on (local addr, local port). Problem is that following sequence : fd = socket(...) connect(fd, &remote, ...) not only selects remote end point (address and port), but also sets local address, while UDP stack stored in secondary hash table the socket while its local address was INADDR_ANY (or ipv6 equivalent) Sequence is : - autobind() : choose a random local port, insert socket in hash tables [while local address is INADDR_ANY] - connect() : set remote address and port, change local address to IP given by a route lookup. When an incoming UDP frame comes, if more than 10 sockets are found in primary hash table, we switch to secondary table, and fail to find socket because its local address changed. One solution to this problem is to rehash datagram socket if needed. We add a new rehash(struct socket *) method in "struct proto", and implement this method for UDP v4 & v6, using a common helper. This rehashing only takes care of secondary hash table, since primary hash (based on local port only) is not changed. Reported-by: Krzysztof Piotr Oledzki <ole@ans.pl> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Tested-by: Krzysztof Piotr Oledzki <ole@ans.pl> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include')
2 files changed, 2 insertions, 0 deletions
diff --git a/include/net/sock.h b/include/net/sock.h
index ac53bfbdfe1..adab9dc5818 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -752,6 +752,7 @@ struct proto {
/* Keeping track of sk's, looking them up, and port selection methods. */
void (*hash)(struct sock *sk);
void (*unhash)(struct sock *sk);
+ void (*rehash)(struct sock *sk);
int (*get_port)(struct sock *sk, unsigned short snum);
/* Keeping track of sockets in use */
diff --git a/include/net/udp.h b/include/net/udp.h
index 7abdf305da5..a184d3496b1 100644
--- a/include/net/udp.h
+++ b/include/net/udp.h
@@ -151,6 +151,7 @@ static inline void udp_lib_hash(struct sock *sk)
extern void udp_lib_unhash(struct sock *sk);
+extern void udp_lib_rehash(struct sock *sk, u16 new_hash);
static inline void udp_lib_close(struct sock *sk, long timeout)