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2009-11-06Merge branch 'master' of ↵David S. Miller
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/net/usb/cdc_ether.c All CDC ethernet devices of type USB_CLASS_COMM need to use '&mbm_info'. Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-30net: fix sk_forward_alloc corruptionEric Dumazet
On UDP sockets, we must call skb_free_datagram() with socket locked, or risk sk_forward_alloc corruption. This requirement is not respected in SUNRPC. Add a convenient helper, skb_free_datagram_locked() and use it in SUNRPC Reported-by: Francis Moreau <francis.moro@gmail.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-18net: sk_drops consolidation part 2Eric Dumazet
- skb_kill_datagram() can increment sk->sk_drops itself, not callers. - UDP on IPV4 & IPV6 dropped frames (because of bad checksum or policy checks) increment sk_drops Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-18inet: rename some inet_sock fieldsEric Dumazet
In order to have better cache layouts of struct sock (separate zones for rx/tx paths), we need this preliminary patch. Goal is to transfert fields used at lookup time in the first read-mostly cache line (inside struct sock_common) and move sk_refcnt to a separate cache line (only written by rx path) This patch adds inet_ prefix to daddr, rcv_saddr, dport, num, saddr, sport and id fields. This allows a future patch to define these fields as macros, like sk_refcnt, without name clashes. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-14net: sk_drops consolidationEric Dumazet
sock_queue_rcv_skb() can update sk_drops itself, removing need for callers to take care of it. This is more consistent since sock_queue_rcv_skb() also reads sk_drops when queueing a skb. This adds sk_drops managment to many protocols that not cared yet. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-13Merge branch 'master' of ↵David S. Miller
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
2009-10-13udp: Fix udp_poll() and ioctl()Eric Dumazet
udp_poll() can in some circumstances drop frames with incorrect checksums. Problem is we now have to lock the socket while dropping frames, or risk sk_forward corruption. This bug is present since commit 95766fff6b9a78d1 ([UDP]: Add memory accounting.) While we are at it, we can correct ioctl(SIOCINQ) to also drop bad frames. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-12net: Generalize socket rx gap / receive queue overflow cmsgNeil Horman
Create a new socket level option to report number of queue overflows Recently I augmented the AF_PACKET protocol to report the number of frames lost on the socket receive queue between any two enqueued frames. This value was exported via a SOL_PACKET level cmsg. AFter I completed that work it was requested that this feature be generalized so that any datagram oriented socket could make use of this option. As such I've created this patch, It creates a new SOL_SOCKET level option called SO_RXQ_OVFL, which when enabled exports a SOL_SOCKET level cmsg that reports the nubmer of times the sk_receive_queue overflowed between any two given frames. It also augments the AF_PACKET protocol to take advantage of this new feature (as it previously did not touch sk->sk_drops, which this patch uses to record the overflow count). Tested successfully by me. Notes: 1) Unlike my previous patch, this patch simply records the sk_drops value, which is not a number of drops between packets, but rather a total number of drops. Deltas must be computed in user space. 2) While this patch currently works with datagram oriented protocols, it will also be accepted by non-datagram oriented protocols. I'm not sure if thats agreeable to everyone, but my argument in favor of doing so is that, for those protocols which aren't applicable to this option, sk_drops will always be zero, and reporting no drops on a receive queue that isn't used for those non-participating protocols seems reasonable to me. This also saves us having to code in a per-protocol opt in mechanism. 3) This applies cleanly to net-next assuming that commit 977750076d98c7ff6cbda51858bb5a5894a9d9ab (my af packet cmsg patch) is reverted Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-07udp: dynamically size hash tables at boot timeEric Dumazet
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>
2009-10-01net: Use sk_mark for routing lookup in more placesAtis Elsts
This patch against v2.6.31 adds support for route lookup using sk_mark in some more places. The benefits from this patch are the following. First, SO_MARK option now has effect on UDP sockets too. Second, ip_queue_xmit() and inet_sk_rebuild_header() could fail to do routing lookup correctly if TCP sockets with SO_MARK were used. Signed-off-by: Atis Elsts <atis@mikrotik.com> Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
2009-09-30net: Make setsockopt() optlen be unsigned.David S. Miller
This provides safety against negative optlen at the type level instead of depending upon (sometimes non-trivial) checks against this sprinkled all over the the place, in each and every implementation. Based upon work done by Arjan van de Ven and feedback from Linus Torvalds. Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-02ip: Report qdisc packet dropsEric Dumazet
Christoph Lameter pointed out that packet drops at qdisc level where not accounted in SNMP counters. Only if application sets IP_RECVERR, drops are reported to user (-ENOBUFS errors) and SNMP counters updated. IP_RECVERR is used to enable extended reliable error message passing, but these are not needed to update system wide SNMP stats. This patch changes things a bit to allow SNMP counters to be updated, regardless of IP_RECVERR being set or not on the socket. Example after an UDP tx flood # netstat -s ... IP: 1487048 outgoing packets dropped ... Udp: ... SndbufErrors: 1487048 send() syscalls, do however still return an OK status, to not break applications. Note : send() manual page explicitly says for -ENOBUFS error : "The output queue for a network interface was full. This generally indicates that the interface has stopped sending, but may be caused by transient congestion. (Normally, this does not occur in Linux. Packets are just silently dropped when a device queue overflows.) " This is not true for IP_RECVERR enabled sockets : a send() syscall that hit a qdisc drop returns an ENOBUFS error. Many thanks to Christoph, David, and last but not least, Alexey ! Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-17udp: cleanupsEric Dumazet
Pure style cleanups. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-12udpv4: Handle large incoming UDP/IPv4 packets and support software UFO.Sridhar Samudrala
- validate and forward GSO UDP/IPv4 packets from untrusted sources. - do software UFO if the outgoing device doesn't support UFO. Signed-off-by: Sridhar Samudrala <sri@us.ibm.com> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-06-18net: correct off-by-one write allocations reportsEric Dumazet
commit 2b85a34e911bf483c27cfdd124aeb1605145dc80 (net: No more expensive sock_hold()/sock_put() on each tx) changed initial sk_wmem_alloc value. We need to take into account this offset when reporting sk_wmem_alloc to user, in PROC_FS files or various ioctls (SIOCOUTQ/TIOCOUTQ) Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-06-03net: skb->dst accessorsEric Dumazet
Define three accessors to get/set dst attached to a skb struct dst_entry *skb_dst(const struct sk_buff *skb) void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst) void skb_dst_drop(struct sk_buff *skb) This one should replace occurrences of : dst_release(skb->dst) skb->dst = NULL; Delete skb->dst field Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-11ipv6: Fix NULL pointer dereference with time-wait socketsVlad Yasevich
Commit b2f5e7cd3dee2ed721bf0675e1a1ddebb849aee6 (ipv6: Fix conflict resolutions during ipv6 binding) introduced a regression where time-wait sockets were not treated correctly. This resulted in the following: BUG: unable to handle kernel NULL pointer dereference at 0000000000000062 IP: [<ffffffff805d7d61>] ipv4_rcv_saddr_equal+0x61/0x70 ... Call Trace: [<ffffffffa033847b>] ipv6_rcv_saddr_equal+0x1bb/0x250 [ipv6] [<ffffffffa03505a8>] inet6_csk_bind_conflict+0x88/0xd0 [ipv6] [<ffffffff805bb18e>] inet_csk_get_port+0x1ee/0x400 [<ffffffffa0319b7f>] inet6_bind+0x1cf/0x3a0 [ipv6] [<ffffffff8056d17c>] ? sockfd_lookup_light+0x3c/0xd0 [<ffffffff8056ed49>] sys_bind+0x89/0x100 [<ffffffff80613ea2>] ? trace_hardirqs_on_thunk+0x3a/0x3c [<ffffffff8020bf9b>] system_call_fastpath+0x16/0x1b Tested-by: Brian Haley <brian.haley@hp.com> Tested-by: Ed Tomlinson <edt@aei.ca> Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-26Merge branch 'master' of ↵David S. Miller
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
2009-03-24ipv6: Fix conflict resolutions during ipv6 bindingVlad Yasevich
The ipv6 version of bind_conflict code calls ipv6_rcv_saddr_equal() which at times wrongly identified intersections between addresses. It particularly broke down under a few instances and caused erroneous bind conflicts. Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-23udp: Wrong locking code in udp seq_file infrastructureVitaly Mayatskikh
Reading zero bytes from /proc/net/udp or other similar files which use the same seq_file udp infrastructure panics kernel in that way: ===================================== [ BUG: bad unlock balance detected! ] ------------------------------------- read/1985 is trying to release lock (&table->hash[i].lock) at: [<ffffffff81321d83>] udp_seq_stop+0x27/0x29 but there are no more locks to release! other info that might help us debug this: 1 lock held by read/1985: #0: (&p->lock){--..}, at: [<ffffffff810eefb6>] seq_read+0x38/0x348 stack backtrace: Pid: 1985, comm: read Not tainted 2.6.29-rc8 #9 Call Trace: [<ffffffff81321d83>] ? udp_seq_stop+0x27/0x29 [<ffffffff8106dab9>] print_unlock_inbalance_bug+0xd6/0xe1 [<ffffffff8106db62>] lock_release_non_nested+0x9e/0x1c6 [<ffffffff810ef030>] ? seq_read+0xb2/0x348 [<ffffffff8106bdba>] ? mark_held_locks+0x68/0x86 [<ffffffff81321d83>] ? udp_seq_stop+0x27/0x29 [<ffffffff8106dde7>] lock_release+0x15d/0x189 [<ffffffff8137163c>] _spin_unlock_bh+0x1e/0x34 [<ffffffff81321d83>] udp_seq_stop+0x27/0x29 [<ffffffff810ef239>] seq_read+0x2bb/0x348 [<ffffffff810eef7e>] ? seq_read+0x0/0x348 [<ffffffff8111aedd>] proc_reg_read+0x90/0xaf [<ffffffff810d878f>] vfs_read+0xa6/0x103 [<ffffffff8106bfac>] ? trace_hardirqs_on_caller+0x12f/0x153 [<ffffffff810d88a2>] sys_read+0x45/0x69 [<ffffffff8101123a>] system_call_fastpath+0x16/0x1b BUG: scheduling while atomic: read/1985/0xffffff00 INFO: lockdep is turned off. Modules linked in: cpufreq_ondemand acpi_cpufreq freq_table dm_multipath kvm ppdev snd_hda_codec_analog snd_hda_intel snd_hda_codec snd_hwdep snd_seq_dummy snd_seq_oss snd_seq_midi_event arc4 snd_s eq ecb thinkpad_acpi snd_seq_device iwl3945 hwmon sdhci_pci snd_pcm_oss sdhci rfkill mmc_core snd_mixer_oss i2c_i801 mac80211 yenta_socket ricoh_mmc i2c_core iTCO_wdt snd_pcm iTCO_vendor_support rs rc_nonstatic snd_timer snd lib80211 cfg80211 soundcore snd_page_alloc video parport_pc output parport e1000e [last unloaded: scsi_wait_scan] Pid: 1985, comm: read Not tainted 2.6.29-rc8 #9 Call Trace: [<ffffffff8106b456>] ? __debug_show_held_locks+0x1b/0x24 [<ffffffff81043660>] __schedule_bug+0x7e/0x83 [<ffffffff8136ede9>] schedule+0xce/0x838 [<ffffffff810d7972>] ? fsnotify_access+0x5f/0x67 [<ffffffff810112d0>] ? sysret_careful+0xb/0x37 [<ffffffff8106be9c>] ? trace_hardirqs_on_caller+0x1f/0x153 [<ffffffff8137127b>] ? trace_hardirqs_on_thunk+0x3a/0x3f [<ffffffff810112f6>] sysret_careful+0x31/0x37 read[1985]: segfault at 7fffc479bfe8 ip 0000003e7420a180 sp 00007fffc479bfa0 error 6 Kernel panic - not syncing: Aiee, killing interrupt handler! udp_seq_stop() tries to unlock not yet locked spinlock. The lock was lost during splitting global udp_hash_lock to subsequent spinlocks. Signed-off by: Vitaly Mayatskikh <v.mayatskih@gmail.com> Acked-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-13Network Drop Monitor: Adding kfree_skb_clean for non-drops and modifying ↵Neil Horman
end-of-line points for skbs Signed-off-by: Neil Horman <nhorman@tuxdriver.com> include/linux/skbuff.h | 4 +++- net/core/datagram.c | 2 +- net/core/skbuff.c | 22 ++++++++++++++++++++++ net/ipv4/arp.c | 2 +- net/ipv4/udp.c | 2 +- net/packet/af_packet.c | 2 +- 6 files changed, 29 insertions(+), 5 deletions(-) Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-15ip: support for TX timestamps on UDP and RAW socketsPatrick Ohly
Instructions for time stamping outgoing packets are take from the socket layer and later copied into the new skb. Signed-off-by: Patrick Ohly <patrick.ohly@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-06udp: Fix potential wrong ip_hdr(skb) pointersJesper Dangaard Brouer
Like the UDP header fix, pskb_may_pull() can potentially alter the SKB buffer. Thus the saddr and daddr, pointers may point to the old skb->data buffer. I haven't seen corruptions, as its only seen if the old skb->data buffer were reallocated by another user and written into very quickly (or poison'd by SLAB debugging). Signed-off-by: Jesper Dangaard Brouer <hawk@comx.dk> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-05udp: Fix UDP short packet false positiveJesper Dangaard Brouer
The UDP header pointer assignment must happen after calling pskb_may_pull(). As pskb_may_pull() can potentially alter the SKB buffer. This was exposted by running multicast traffic through the NIU driver, as it won't prepull the protocol headers into the linear area on receive. Signed-off-by: Jesper Dangaard Brouer <hawk@comx.dk> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-02udp: increments sk_drops in __udp_queue_rcv_skb()Eric Dumazet
Commit 93821778def10ec1e69aa3ac10adee975dad4ff3 (udp: Fix rcv socket locking) accidentally removed sk_drops increments for UDP IPV4 sockets. This field can be used to detect incorrect sizing of socket receive buffers. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-01-26udp: optimize bind(0) if many ports are in useEric Dumazet
commit 9088c5609584684149f3fb5b065aa7f18dcb03ff (udp: Improve port randomization) introduced a regression for UDP bind() syscall to null port (getting a random port) in case lot of ports are already in use. This is because we do about 28000 scans of very long chains (220 sockets per chain), with many spin_lock_bh()/spin_unlock_bh() calls. Fix this using a bitmap (64 bytes for current value of UDP_HTABLE_SIZE) so that we scan chains at most once. Instead of 250 ms per bind() call, we get after patch a time of 2.9 ms Based on a report from Vitaly Mayatskikh Reported-by: Vitaly Mayatskikh <v.mayatskih@gmail.com> Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Tested-by: Vitaly Mayatskikh <v.mayatskih@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-25net: udp_unhash() can test if sk is hashedEric Dumazet
Impact: Optimization Like done in inet_unhash(), we can avoid taking a chain lock if socket is not hashed in udp_unhash() Triggered by close(socket(AF_INET, SOCK_DGRAM, 0)); Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-24net: avoid a pair of dst_hold()/dst_release() in ip_append_data()Eric Dumazet
We can reduce pressure on dst entry refcount that slowdown UDP transmit path on SMP machines. This pressure is visible on RTP servers when delivering content to mediagateways, especially big ones, handling thousand of streams. Several cpus send UDP frames to the same destination, hence use the same dst entry. This patch makes ip_append_data() eventually steal the refcount its callers had to take on the dst entry. This doesnt avoid all refcounting, but still gives speedups on SMP, on UDP/RAW transmit path Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-20Merge branch 'master' of ↵David S. Miller
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/net/ixgbe/ixgbe_main.c include/net/mac80211.h net/phonet/af_phonet.c
2008-11-20TPROXY: fill struct flowi->flags in udp_sendmsg()Balazs Scheidler
udp_sendmsg() didn't fill struct flowi->flags, which means that the route lookup would fail for non-local IPs even if the IP_TRANSPARENT sockopt was set. This prevents sendto() to work properly for UDP sockets, whereas bind(foreign-ip) + connect() + send() worked fine. Signed-off-by: Balazs Scheidler <bazsi@balabit.hu> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-16udp: Use hlist_nulls in UDP RCU codeEric Dumazet
This is a straightforward patch, using hlist_nulls infrastructure. RCUification already done on UDP two weeks ago. Using hlist_nulls permits us to avoid some memory barriers, both at lookup time and delete time. Patch is large because it adds new macros to include/net/sock.h. These macros will be used by TCP & DCCP in next patch. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-06Merge branch 'master' of ↵David S. Miller
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/net/wireless/ath5k/base.c net/8021q/vlan_core.c
2008-11-01udp: multicast packets need to check namespaceEric Dumazet
Current UDP multicast delivery is not namespace aware. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Acked-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-11-01udp: add a missing smp_wmb() in udp_lib_get_port()Eric Dumazet
Corey Minyard spotted a missing memory barrier in udp_lib_get_port() We need to make sure a reader cannot read the new 'sk->sk_next' value and previous value of 'sk->sk_hash'. Or else, an item could be deleted from a chain, and inserted into another chain. If new chain was empty before the move, 'next' pointer is NULL, and lockless reader can not detect it missed following items in original chain. This patch is temporary, since we expect an upcoming patch to introduce another way of handling the problem. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-31net: replace NIPQUAD() in net/ipv4/ net/ipv6/Harvey Harrison
Using NIPQUAD() with NIPQUAD_FMT, %d.%d.%d.%d or %u.%u.%u.%u can be replaced with %pI4 Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-30udp: Should use spin_lock_bh()/spin_unlock_bh() in udp_lib_unhash()Eric Dumazet
Spotted by Alexander Beregalov Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-29udp: introduce sk_for_each_rcu_safenext()Eric Dumazet
Corey Minyard found a race added in commit 271b72c7fa82c2c7a795bc16896149933110672d (udp: RCU handling for Unicast packets.) "If the socket is moved from one list to another list in-between the time the hash is calculated and the next field is accessed, and the socket has moved to the end of the new list, the traversal will not complete properly on the list it should have, since the socket will be on the end of the new list and there's not a way to tell it's on a new list and restart the list traversal. I think that this can be solved by pre-fetching the "next" field (with proper barriers) before checking the hash." This patch corrects this problem, introducing a new sk_for_each_rcu_safenext() macro. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-29udp: udp_get_next() should use spin_unlock_bh()Eric Dumazet
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-29udp: calculate udp_mem based on low memory instead of all memoryEric Dumazet
This patch mimics commit 57413ebc4e0f1e471a3b4db4aff9a85c083d090e (tcp: calculate tcp_mem based on low memory instead of all memory) The udp_mem array which contains limits on the total amount of memory used by UDP sockets is calculated based on nr_all_pages. On a 32 bits x86 system, we should base this on the number of lowmem pages. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-29udp: RCU handling for Unicast packets.Eric Dumazet
Goals are : 1) Optimizing handling of incoming Unicast UDP frames, so that no memory writes should happen in the fast path. Note: Multicasts and broadcasts still will need to take a lock, because doing a full lockless lookup in this case is difficult. 2) No expensive operations in the socket bind/unhash phases : - No expensive synchronize_rcu() calls. - No added rcu_head in socket structure, increasing memory needs, but more important, forcing us to use call_rcu() calls, that have the bad property of making sockets structure cold. (rcu grace period between socket freeing and its potential reuse make this socket being cold in CPU cache). David did a previous patch using call_rcu() and noticed a 20% impact on TCP connection rates. Quoting Cristopher Lameter : "Right. That results in cacheline cooldown. You'd want to recycle the object as they are cache hot on a per cpu basis. That is screwed up by the delayed regular rcu processing. We have seen multiple regressions due to cacheline cooldown. The only choice in cacheline hot sensitive areas is to deal with the complexity that comes with SLAB_DESTROY_BY_RCU or give up on RCU." - Because udp sockets are allocated from dedicated kmem_cache, use of SLAB_DESTROY_BY_RCU can help here. Theory of operation : --------------------- As the lookup is lockfree (using rcu_read_lock()/rcu_read_unlock()), special attention must be taken by readers and writers. Use of SLAB_DESTROY_BY_RCU is tricky too, because a socket can be freed, reused, inserted in a different chain or in worst case in the same chain while readers could do lookups in the same time. In order to avoid loops, a reader must check each socket found in a chain really belongs to the chain the reader was traversing. If it finds a mismatch, lookup must start again at the begining. This *restart* loop is the reason we had to use rdlock for the multicast case, because we dont want to send same message several times to the same socket. We use RCU only for fast path. Thus, /proc/net/udp still takes spinlocks. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-29udp: introduce struct udp_table and multiple spinlocksEric Dumazet
UDP sockets are hashed in a 128 slots hash table. This hash table is protected by *one* rwlock. This rwlock is readlocked each time an incoming UDP message is handled. This rwlock is writelocked each time a socket must be inserted in hash table (bind time), or deleted from this table (close time) This is not scalable on SMP machines : 1) Even in read mode, lock() and unlock() are atomic operations and must dirty a contended cache line, shared by all cpus. 2) A writer might be starved if many readers are 'in flight'. This can happen on a machine with some NIC receiving many UDP messages. User process can be delayed a long time at socket creation/dismantle time. This patch prepares RCU migration, by introducing 'struct udp_table and struct udp_hslot', and using one spinlock per chain, to reduce contention on central rwlock. Introducing one spinlock per chain reduces latencies, for port randomization on heavily loaded UDP servers. This also speedup bindings to specific ports. udp_lib_unhash() was uninlined, becoming to big. Some cleanups were done to ease review of following patch (RCUification of UDP Unicast lookups) Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-13net: Rationalise email address: Network Specific PartsAlan Cox
Clean up the various different email addresses of mine listed in the code to a single current and valid address. As Dave says his network merges for 2.6.28 are now done this seems a good point to send them in where they won't risk disrupting real changes. Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-09udp: complete port availability checkingEric Dumazet
While looking at UDP port randomization, I noticed it was litle bit pessimistic, not looking at type of sockets (IPV6/IPV4) and not looking at bound addresses if any. We should perform same tests than when binding to a specific port. This permits a cleanup of udp_lib_get_port() Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-08udp: Improve port randomizationEric Dumazet
Current UDP port allocation is suboptimal. We select the shortest chain to chose a port (out of 512) that will hash in this shortest chain. First, it can lead to give not so ramdom ports and ease give attackers more opportunities to break the system. Second, it can consume a lot of CPU to scan all table in order to find the shortest chain. Third, in some pathological cases we can fail to find a free port even if they are plenty of them. This patch zap the search for a short chain and only use one random seed. Problem of getting long chains should be addressed in another way, since we can obtain long chains with non random ports. Based on a report and patch from Vitaly Mayatskikh Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-07netns: make udpv6 mib per/namespaceDenis V. Lunev
Signed-off-by: Denis V. Lunev <den@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-07inet: Don't lookup the socket if there's a socket attached to the skbKOVACS Krisztian
Use the socket cached in the skb if it's present. Signed-off-by: KOVACS Krisztian <hidden@sch.bme.hu> Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-07inet: Add udplib_lookup_skb() helpersKOVACS Krisztian
To be able to use the cached socket reference in the skb during input processing we add a new set of lookup functions that receive the skb on their argument list. Signed-off-by: KOVACS Krisztian <hidden@sch.bme.hu> Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-01udp: Export UDP socket lookup functionKOVACS Krisztian
The iptables tproxy code has to be able to do UDP socket hash lookups, so we have to provide an exported lookup function for this purpose. Signed-off-by: KOVACS Krisztian <hidden@sch.bme.hu> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-09-15udp: Fix rcv socket lockingHerbert Xu
The previous patch in response to the recursive locking on IPsec reception is broken as it tries to drop the BH socket lock while in user context. This patch fixes it by shrinking the section protected by the socket lock to sock_queue_rcv_skb only. The only reason we added the lock is for the accounting which happens in that function. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-08-09udp: Drop socket lock for encapsulated packetsHerbert Xu
The socket lock is there to protect the normal UDP receive path. Encapsulation UDP sockets don't need that protection. In fact the locking is deadly for them as they may contain another UDP packet within, possibly with the same addresses. Also the nested bit was copied from TCP. TCP needs it because of accept(2) spawning sockets. This simply doesn't apply to UDP so I've removed it. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
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