linux-toradex.git/include/net/udp.h, branch v3.0.29

udp: Switch to ip_finish_skb

2011-03-01T20:35:03+00:00

This patch converts UDP to use the new ip_finish_skb API.  This
would then allows us to more easily use ip_make_skb which allows
UDP to run without a socket lock.

Signed-off-by: Herbert Xu 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller

net: change netdev->features to u32

2011-01-24T23:32:47+00:00

Quoting Ben Hutchings: we presumably won't be defining features that
can only be enabled on 64-bit architectures.

Occurences found by `grep -r` on net/, drivers/net, include/

[ Move features and vlan_features next to each other in
  struct netdev, as per Eric Dumazet's suggestion -DaveM ]

Signed-off-by: Michał Mirosław 
Signed-off-by: David S. Miller

net: avoid limits overflow

2010-11-10T20:12:00+00:00

Robin Holt tried to boot a 16TB machine and found some limits were
reached : sysctl_tcp_mem[2], sysctl_udp_mem[2]

We can switch infrastructure to use long "instead" of "int", now
atomic_long_t primitives are available for free.

Signed-off-by: Eric Dumazet 
Reported-by: Robin Holt 
Reviewed-by: Robin Holt 
Signed-off-by: Andrew Morton 
Signed-off-by: David S. Miller

tproxy: added udp6_lib_lookup function

2010-10-21T14:05:41+00:00

Just like with IPv4, we need access to the UDP hash table to look up local
sockets, but instead of exporting the global udp_table, export a lookup
function.

Signed-off-by: Balazs Scheidler 
Signed-off-by: KOVACS Krisztian 
Signed-off-by: Patrick McHardy

udp: add rehash on connect()

2010-09-09T04:45:01+00:00

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 
Signed-off-by: Eric Dumazet 
Tested-by: Krzysztof Piotr Oledzki 
Signed-off-by: David S. Miller

net: cleanups

2010-07-13T03:21:45+00:00

remove useless blanks.

Signed-off-by: Changli Gao 
----
 include/net/inet_common.h |   55 ++++-------
 include/net/tcp.h         |  222 +++++++++++++++++-----------------------------
 include/net/udp.h         |   38 +++----
 3 files changed, 123 insertions(+), 192 deletions(-)
Signed-off-by: David S. Miller

udp: bind() optimisation

2009-11-11T04:54:38+00:00

UDP bind() can be O(N^2) in some pathological cases.

Thanks to secondary hash tables, we can make it O(N)

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

udp: secondary hash on (local port, local address)

2009-11-09T04:53:06+00:00

Extends udp_table to contain a secondary hash table.

socket anchor for this second hash is free, because UDP
doesnt use skc_bind_node : We define an union to hold
both skc_bind_node & a new hlist_nulls_node udp_portaddr_node

udp_lib_get_port() inserts sockets into second hash chain
(additional cost of one atomic op)

udp_lib_unhash() deletes socket from second hash chain
(additional cost of one atomic op)

Note : No spinlock lockdep annotation is needed, because
lock for the secondary hash chain is always get after
lock for primary hash chain.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

udp: add a counter into udp_hslot

2009-11-09T04:53:04+00:00

Adds a counter in udp_hslot to keep an accurate count
of sockets present in chain.

This will permit to upcoming UDP lookup algo to chose
the shortest chain when secondary hash is added.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

udp: dynamically size hash tables at boot time

2009-10-08T05:00:22+00:00

UDP_HTABLE_SIZE was initialy defined to 128, which is a bit small for
several setups.

4000 active UDP sockets -> 32 sockets per chain in average. An
incoming frame has to lookup all sockets to find best match, so long
chains hurt latency.

Instead of a fixed size hash table that cant be perfect for every
needs, let UDP stack choose its table size at boot time like tcp/ip
route, using alloc_large_system_hash() helper

Add an optional boot parameter, uhash_entries=x so that an admin can
force a size between 256 and 65536 if needed, like thash_entries and
rhash_entries.

dmesg logs two new lines :
[    0.647039] UDP hash table entries: 512 (order: 0, 4096 bytes)
[    0.647099] UDP Lite hash table entries: 512 (order: 0, 4096 bytes)

Maximal size on 64bit arches would be 65536 slots, ie 1 MBytes for non
debugging spinlocks.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller