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 <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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 <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Union sk_hash with two u16 hashes for udp (no extra memory taken)
One 16 bits hash on (local port) value (the previous udp 'hash')
One 16 bits hash on (local address, local port) values, initialized
but not yet used. This second hash is using jenkin hash for better
distribution.
Because the 'port' is xored later, a partial hash is performed
on local address + net_hash_mix(net)
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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 <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There are many possible ways to add this "salt", thus I made this
patch to be the last in the series to change it if required.
Currently I propose to use the struct net pointer itself as this
salt, but since this pointer is most often cache-line aligned, shift
this right to eliminate the bits, that are most often zeroed.
After this, simply add this mix to prepared hashfn-s.
For CONFIG_NET_NS=n case this salt is 0 and no changes in hashfn
appear.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Every caller already has this one. The new argument is currently
unused, but this will be fixed shortly.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently the chain to store a UDP socket is calculated with
simple (x & (UDP_HTABLE_SIZE - 1)). But taking net into account
would make this calculation a bit more complex, so moving it into
a function would help.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Remove duplicate #include <linux/types.h>
Combine #ifdef __KERNEL__ blocks
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This reverts commit db1ed684f6 ("[IPV6]
UDP: Rename IPv6 UDP files."), commit
8be8af8fa4 ("[IPV4] UDP: Move
IPv4-specific bits to other file.") and commit
e898d4db27 ("[UDP]: Allow users to
configure UDP-Lite.").
First, udplite is of such small cost, and it is a core protocol just
like TCP and normal UDP are.
We spent enormous amounts of effort to make udplite share as much code
with core UDP as possible. All of that work is less valuable if we're
just going to slap a config option on udplite support.
It is also causing build failures, as reported on linux-next, showing
that the changeset was not tested very well. In fact, this is the
second build failure resulting from the udplite change.
Finally, the config options provided was a bool, instead of a modular
option. Meaning the udplite code does not even get build tested
by allmodconfig builds, and furthermore the user is not presented
with a reasonable modular build option which is particularly needed
by distribution vendors.
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds a new UDP_ENCAP_L2TPINUDP encapsulation type for UDP
sockets. When a UDP socket's encap_type is UDP_ENCAP_L2TPINUDP, the
skb is delivered to a function pointed to by the udp_sock's
encap_rcv funcptr. If the skb isn't wanted by L2TP, it returns >0, which
causes it to be passed through to UDP.
Include padding to put the new encap_rcv field on a 4-byte boundary.
Previously, the only user of UDP encap sockets was ESP, so when
CONFIG_XFRM was not defined, some of the encap code was compiled
out. This patch changes that. As a result, udp_encap_rcv() will
now do a little more work when CONFIG_XFRM is not defined.
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
For the places where we need a pointer to the transport header, it is
still legal to touch skb->h.raw directly if just adding to,
subtracting from or setting it to another layer header.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is a revision of the previously submitted patch, which alters
the way files are organized and compiled in the following manner:
* UDP and UDP-Lite now use separate object files
* source file dependencies resolved via header files
net/ipv{4,6}/udp_impl.h
* order of inclusion files in udp.c/udplite.c adapted
accordingly
[NET/IPv4]: Support for the UDP-Lite protocol (RFC 3828)
This patch adds support for UDP-Lite to the IPv4 stack, provided as an
extension to the existing UDPv4 code:
* generic routines are all located in net/ipv4/udp.c
* UDP-Lite specific routines are in net/ipv4/udplite.c
* MIB/statistics support in /proc/net/snmp and /proc/net/udplite
* shared API with extensions for partial checksum coverage
[NET/IPv6]: Extension for UDP-Lite over IPv6
It extends the existing UDPv6 code base with support for UDP-Lite
in the same manner as per UDPv4. In particular,
* UDPv6 generic and shared code is in net/ipv6/udp.c
* UDP-Litev6 specific extensions are in net/ipv6/udplite.c
* MIB/statistics support in /proc/net/snmp6 and /proc/net/udplite6
* support for IPV6_ADDRFORM
* aligned the coding style of protocol initialisation with af_inet6.c
* made the error handling in udpv6_queue_rcv_skb consistent;
to return `-1' on error on all error cases
* consolidation of shared code
[NET]: UDP-Lite Documentation and basic XFRM/Netfilter support
The UDP-Lite patch further provides
* API documentation for UDP-Lite
* basic xfrm support
* basic netfilter support for IPv4 and IPv6 (LOG target)
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
To help in reducing the number of include dependencies, several files were
touched as they were getting needed headers indirectly for stuff they use.
Thanks also to Alan Menegotto for pointing out that net/dccp/proto.c had
linux/dccp.h include twice.
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Eric Dumazet