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2012-05-04net: sched: factorize code (qdisc_drop())Eric Dumazet4-13/+6
Use qdisc_drop() helper where possible. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-03skb: Add skb_head_is_locked helper functionAlexander Duyck2-3/+2
This patch adds support for a skb_head_is_locked helper function. It is meant to be used any time we are considering transferring the head from skb->head to a paged frag. If the head is locked it means we cannot remove the head from the skb so it must be copied or we must take the skb as a whole. Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-03net: Fix truesize accounting in skb_gro_receive()Eric Dumazet1-3/+8
GRO is very optimistic in skb truesize estimates, only taking into account the used part of fragments. Be conservative, and use more precise computation, so that bloated GRO skbs can be collapsed eventually. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Alexander Duyck <alexander.h.duyck@intel.com> Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Acked-by: Alexander Duyck <alexander.h.duyck@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-03tcp: move stats merge to the end of tcp_try_coalesceAlexander Duyck1-26/+29
This change cleans up the last bits of tcp_try_coalesce so that we only need one goto which jumps to the end of the function. The idea is to make the code more readable by putting things in a linear order so that we start execution at the top of the function, and end it at the bottom. I also made a slight tweak to the code for handling frags when we are a clone. Instead of making it an if (clone) loop else nr_frags = 0 I changed the logic so that if (!clone) we just set the number of frags to 0 which disables the for loop anyway. Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-03tcp: Move code related to head frag in tcp_try_coalesceAlexander Duyck1-17/+25
This change reorders the code related to the use of an skb->head_frag so it is placed before we check the rest of the frags. This allows the code to read more linearly instead of like some sort of loop. Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-03tcp: Fix truesize accounting in tcp_try_coalesceAlexander Duyck1-6/+4
This patch addresses several issues in the way we were tracking the truesize in tcp_try_coalesce. First it was using ksize which prevents us from having a 0 sized head frag and getting a usable result. To resolve that this patch uses the end pointer which is set based off either ksize, or the frag_size supplied in build_skb. This allows us to compute the original truesize of the entire buffer and remove that value leaving us with just what was added as pages. The second issue was the use of skb->len if there is a mergeable head frag. We should only need to remove the size of an data aligned sk_buff from our current skb->truesize to compute the delta for a buffer with a reused head. By using skb->len the value of truesize was being artificially reduced which means that head frags could use more memory than buffers using standard allocations. Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-03net: Add missing linux/prefetch.h include to net/core/sock.cDavid S. Miller1-0/+1
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-03net: Stop decapitating clones that have a head_fragAlexander Duyck2-11/+7
This change is meant ot prevent stealing the skb->head to use as a page in the event that the skb->head was cloned. This allows the other clones to track each other via shinfo->dataref. Without this we break down to two methods for tracking the reference count, one being dataref, the other being the page count. As a result it becomes difficult to track how many references there are to skb->head. Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-03net: implement tcp coalescing in tcp_queue_rcv()Eric Dumazet2-24/+26
Extend tcp coalescing implementing it from tcp_queue_rcv(), the main receiver function when application is not blocked in recvmsg(). Function tcp_queue_rcv() is moved a bit to allow its call from tcp_data_queue() This gives good results especially if GRO could not kick, and if skb head is a fragment. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Alexander Duyck <alexander.h.duyck@intel.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-03net: take care of cloned skbs in tcp_try_coalesce()Eric Dumazet1-14/+28
Before stealing fragments or skb head, we must make sure skbs are not cloned. Alexander was worried about destination skb being cloned : In bridge setups, a driver could be fooled if skb->data_len would not match skb nr_frags. If source skb is cloned, we must take references on pages instead. Bug happened using tcpdump (if not using mmap()) Introduce kfree_skb_partial() helper to cleanup code. Reported-by: Alexander Duyck <alexander.h.duyck@intel.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-03tcp: early retransmit: delayed fast retransmitYuchung Cheng3-10/+69
Implementing the advanced early retransmit (sysctl_tcp_early_retrans==2). Delays the fast retransmit by an interval of RTT/4. We borrow the RTO timer to implement the delay. If we receive another ACK or send a new packet, the timer is cancelled and restored to original RTO value offset by time elapsed. When the delayed-ER timer fires, we enter fast recovery and perform fast retransmit. Signed-off-by: Yuchung Cheng <ycheng@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-03tcp: early retransmitYuchung Cheng4-0/+29
This patch implements RFC 5827 early retransmit (ER) for TCP. It reduces DUPACK threshold (dupthresh) if outstanding packets are less than 4 to recover losses by fast recovery instead of timeout. While the algorithm is simple, small but frequent network reordering makes this feature dangerous: the connection repeatedly enter false recovery and degrade performance. Therefore we implement a mitigation suggested in the appendix of the RFC that delays entering fast recovery by a small interval, i.e., RTT/4. Currently ER is conservative and is disabled for the rest of the connection after the first reordering event. A large scale web server experiment on the performance impact of ER is summarized in section 6 of the paper "Proportional Rate Reduction for TCP”, IMC 2011. http://conferences.sigcomm.org/imc/2011/docs/p155.pdf Note that Linux has a similar feature called THIN_DUPACK. The differences are THIN_DUPACK do not mitigate reorderings and is only used after slow start. Currently ER is disabled if THIN_DUPACK is enabled. I would be happy to merge THIN_DUPACK feature with ER if people think it's a good idea. ER is enabled by sysctl_tcp_early_retrans: 0: Disables ER 1: Reduce dupthresh to packets_out - 1 when outstanding packets < 4. 2: (Default) reduce dupthresh like mode 1. In addition, delay entering fast recovery by RTT/4. Note: mode 2 is implemented in the third part of this patch series. Signed-off-by: Yuchung Cheng <ycheng@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-03tcp: early retransmit: tcp_enter_recovery()Yuchung Cheng1-27/+34
This a prepartion patch that refactors the code to enter recovery into a new function tcp_enter_recovery(). It's needed to implement the delayed fast retransmit in ER. Signed-off-by: Yuchung Cheng <ycheng@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-01netem: add ECN capabilityEric Dumazet1-3/+15
Add ECN (Explicit Congestion Notification) marking capability to netem tc qdisc add dev eth0 root netem drop 0.5 ecn Instead of dropping packets, try to ECN mark them. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Tom Herbert <therbert@google.com> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Cc: Stephen Hemminger <shemminger@vyatta.com> Acked-by: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-01net: add a prefetch in socket backlog processingEric Dumazet1-0/+1
TCP or UDP stacks have big enough latencies that prefetching next pointer is worth it. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-01l2tp: let iproute2 create L2TPv3 IP tunnels using IPv6James Chapman1-22/+50
The netlink API lets users create unmanaged L2TPv3 tunnels using iproute2. Until now, a request to create an unmanaged L2TPv3 IP encapsulation tunnel over IPv6 would be rejected with EPROTONOSUPPORT. Now that l2tp_ip6 implements sockets for L2TP IP encapsulation over IPv6, we can add support for that tunnel type. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-01l2tp: introduce L2TPv3 IP encapsulation support for IPv6Chris Elston2-0/+795
L2TPv3 defines an IP encapsulation packet format where data is carried directly over IP (no UDP). The kernel already has support for L2TP IP encapsulation over IPv4 (l2tp_ip). This patch introduces support for L2TP IP encapsulation over IPv6. The implementation is derived from ipv6/raw and ipv4/l2tp_ip. Signed-off-by: Chris Elston <celston@katalix.com> Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-01ipv6: Export ipv6 functions for use by other protocolsChris Elston4-0/+9
For implementing other protocols on top of IPv6, such as L2TPv3's IP encapsulation over ipv6, we'd like to call some IPv6 functions which are not currently exported. This patch exports them. Signed-off-by: Chris Elston <celston@katalix.com> Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-01l2tp: netlink api for l2tpv3 ipv6 unmanaged tunnelsChris Elston3-21/+109
This patch adds support for unmanaged L2TPv3 tunnels over IPv6 using the netlink API. We already support unmanaged L2TPv3 tunnels over IPv4. A patch to iproute2 to make use of this feature will be submitted separately. Signed-off-by: Chris Elston <celston@katalix.com> Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-01l2tp: show IPv6 addresses in l2tp debugfs fileChris Elston1-0/+8
If an L2TP tunnel uses IPv6, make sure the l2tp debugfs file shows the IPv6 address correctly. Signed-off-by: Chris Elston <celston@katalix.com> Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-01l2tp: pppol2tp_connect() handles ipv6 sockaddr variantsJames Chapman1-8/+28
Userspace uses connect() to associate a pppol2tp socket with a tunnel socket. This needs to allow the caller to supply the new IPv6 sockaddr_pppol2tp structures if IPv6 is used. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-01l2tp: remove unused stats from l2tp_ip socketJames Chapman1-28/+4
The l2tp_ip socket currently maintains packet/byte stats in its private socket structure. But these counters aren't exposed to userspace and so serve no purpose. The counters were also smp-unsafe. So this patch just gets rid of the stats. While here, change a couple of internal __u32 variables to u32. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-01l2tp: Use ip4_datagram_connect() in l2tp_ip_connect()James Chapman1-47/+7
Cleanup the l2tp_ip code to make use of an existing ipv4 support function. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-01l2tp: fix locking of 64-bit counters for smpJames Chapman3-35/+103
L2TP uses 64-bit counters but since these are not updated atomically, we need to make them safe for smp. This patch addresses that. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-01Merge branch 'tipc_net-next' of ↵David S. Miller34-567/+58
git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux
2012-05-01net: makes skb_splice_bits() aware of skb->head_fragEric Dumazet1-3/+7
__skb_splice_bits() can check if skb to be spliced has its skb->head mapped to a page fragment, instead of a kmalloc() area. If so we can avoid a copy of the skb head and get a reference on underlying page. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Maciej Żenczykowski <maze@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Tom Herbert <therbert@google.com> Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Matt Carlson <mcarlson@broadcom.com> Cc: Michael Chan <mchan@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-01tcp: makes tcp_try_coalesce aware of skb->head_fragEric Dumazet1-12/+43
TCP coalesce can check if skb to be merged has its skb->head mapped to a page fragment, instead of a kmalloc() area. We had to disable coalescing in this case, for performance reasons. We 'upgrade' skb->head as a fragment in itself. This reduces number of cache misses when user makes its copies, since a less sk_buff are fetched. This makes receive and ofo queues shorter and thus reduce cache line misses in TCP stack. This is a followup of patch "net: allow skb->head to be a page fragment" Tested with tg3 nic, with GRO on or off. We can see "TCPRcvCoalesce" counter being incremented. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Maciej Żenczykowski <maze@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Tom Herbert <therbert@google.com> Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Matt Carlson <mcarlson@broadcom.com> Cc: Michael Chan <mchan@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-01net: make GRO aware of skb->head_fragEric Dumazet2-2/+30
GRO can check if skb to be merged has its skb->head mapped to a page fragment, instead of a kmalloc() area. We 'upgrade' skb->head as a fragment in itself This avoids the frag_list fallback, and permits to build true GRO skb (one sk_buff and up to 16 fragments), using less memory. This reduces number of cache misses when user makes its copy, since a single sk_buff is fetched. This is a followup of patch "net: allow skb->head to be a page fragment" Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Maciej Żenczykowski <maze@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Tom Herbert <therbert@google.com> Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Matt Carlson <mcarlson@broadcom.com> Cc: Michael Chan <mchan@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-01net: allow skb->head to be a page fragmentEric Dumazet1-6/+18
skb->head is currently allocated from kmalloc(). This is convenient but has the drawback the data cannot be converted to a page fragment if needed. We have three spots were it hurts : 1) GRO aggregation When a linear skb must be appended to another skb, GRO uses the frag_list fallback, very inefficient since we keep all struct sk_buff around. So drivers enabling GRO but delivering linear skbs to network stack aren't enabling full GRO power. 2) splice(socket -> pipe). We must copy the linear part to a page fragment. This kind of defeats splice() purpose (zero copy claim) 3) TCP coalescing. Recently introduced, this permits to group several contiguous segments into a single skb. This shortens queue lengths and save kernel memory, and greatly reduce probabilities of TCP collapses. This coalescing doesnt work on linear skbs (or we would need to copy data, this would be too slow) Given all these issues, the following patch introduces the possibility of having skb->head be a fragment in itself. We use a new skb flag, skb->head_frag to carry this information. build_skb() is changed to accept a frag_size argument. Drivers willing to provide a page fragment instead of kmalloc() data will set a non zero value, set to the fragment size. Then, on situations we need to convert the skb head to a frag in itself, we can check if skb->head_frag is set and avoid the copies or various fallbacks we have. This means drivers currently using frags could be updated to avoid the current skb->head allocation and reduce their memory footprint (aka skb truesize). (thats 512 or 1024 bytes saved per skb). This also makes bpf/netfilter faster since the 'first frag' will be part of skb linear part, no need to copy data. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Maciej Żenczykowski <maze@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Tom Herbert <therbert@google.com> Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Cc: Ben Hutchings <bhutchings@solarflare.com> Cc: Matt Carlson <mcarlson@broadcom.com> Cc: Michael Chan <mchan@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-30tipc: compress out gratuitous extra carriage returnsPaul Gortmaker32-530/+16
Some of the comment blocks are floating in limbo between two functions, or between blocks of code. Delete the extra line feeds between any comment and its associated following block of code, to be consistent with the majority of the rest of the kernel. Also delete trailing newlines at EOF and fix a couple trivial typos in existing comments. This is a 100% cosmetic change with no runtime impact. We get rid of over 500 lines of non-code, and being blank line deletes, they won't even show up as noise in git blame. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-04-30bridge: Fix fatal typo in setup of multicast_querier_expiredHerbert Xu1-3/+2
Unfortunately it seems that I didn't properly test the case of an expired external querier in the recent multicast bridge series. The setup of the timer in that case is completely broken and leads to a NULL-pointer dereference. This patch fixes it. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Acked-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-30l2tp: Add missing net/net/ip6_checksum.h include.David S. Miller1-0/+1
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-29net/l2tp: add support for L2TP over IPv6 UDPBenjamin LaHaise2-13/+118
Now that encap_rcv() works on IPv6 UDP sockets, wire L2TP up to IPv6. Support has been tested with and without hardware offloading. This version fixes the L2TP over localhost issue with incorrect checksums being reported. Signed-off-by: Benjamin LaHaise <bcrl@kvack.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-29net/ipv6/udp: UDP encapsulation: introduce encap_rcv hook into IPv6Benjamin LaHaise1-0/+39
Now that the sematics of udpv6_queue_rcv_skb() match IPv4's udp_queue_rcv_skb(), introduce the UDP encap_rcv() hook for IPv6. Signed-off-by: Benjamin LaHaise <bcrl@kvack.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-29net/ipv6/udp: UDP encapsulation: move socket locking into udpv6_queue_rcv_skb()Benjamin LaHaise1-53/+44
In order to make sure that when the encap_rcv() hook is introduced it is not called with the socket lock held, move socket locking from callers into udpv6_queue_rcv_skb(), matching what happens in IPv4. Signed-off-by: Benjamin LaHaise <bcrl@kvack.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-29net/ipv6/udp: UDP encapsulation: break backlog_rcv into __udpv6_queue_rcv_skbBenjamin LaHaise1-15/+27
This is the first step in reworking the IPv6 UDP code to be structured more like the IPv4 UDP code. This patch creates __udpv6_queue_rcv_skb() with the equivalent sematics to __udp_queue_rcv_skb(), and wires it up to the backlog_rcv method. Signed-off-by: Benjamin LaHaise <bcrl@kvack.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-29net: Fixed a coding style issue related to spaces.Jeffrin Jose1-1/+1
Fixed a coding style issue relating to spaces in net/core/sock.c Signed-off-by: Jeffrin Jose <ahiliation@yahoo.co.in> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-27tipc: Reject payload messages with invalid message typeAllan Stephens1-5/+2
Adds check to ensure TIPC sockets reject incoming payload messages that have an unrecognized message type. Remove the old open question about whether TIPC_ERR_NO_PORT is the proper return value. It is appropriate here since there are valid instances where another node can make use of the reply, and at this point in time the host is already broadcasting TIPC data, so there are no real security concerns. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-04-27net: cleanups in sock_setsockopt()Eric Dumazet1-27/+15
Use min_t()/max_t() macros, reformat two comments, use !!test_bit() to match !!sock_flag() Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-27crush: include header for global symbolshartleys1-0/+1
Include the header to pickup the definitions of the global symbols. Quiets the following sparse warnings: warning: symbol 'crush_find_rule' was not declared. Should it be static? warning: symbol 'crush_do_rule' was not declared. Should it be static? Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Cc: Sage Weil <sage@newdream.net> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-27ipv6: RTAX_FEATURE_ALLFRAG causes inefficient TCP segment sizingEric Dumazet2-2/+18
Quoting Tore Anderson from : https://bugzilla.kernel.org/show_bug.cgi?id=42572 When RTAX_FEATURE_ALLFRAG is set on a route, the effective TCP segment size does not take into account the size of the IPv6 Fragmentation header that needs to be included in outbound packets, causing every transmitted TCP segment to be fragmented across two IPv6 packets, the latter of which will only contain 8 bytes of actual payload. RTAX_FEATURE_ALLFRAG is typically set on a route in response to receving a ICMPv6 Packet Too Big message indicating a Path MTU of less than 1280 bytes. 1280 bytes is the minimum IPv6 MTU, however ICMPv6 PTBs with MTU < 1280 are still valid, in particular when an IPv6 packet is sent to an IPv4 destination through a stateless translator. Any ICMPv4 Need To Fragment packets originated from the IPv4 part of the path will be translated to ICMPv6 PTB which may then indicate an MTU of less than 1280. The Linux kernel refuses to reduce the effective MTU to anything below 1280 bytes, instead it sets it to exactly 1280 bytes, and RTAX_FEATURE_ALLFRAG is also set. However, the TCP segment size appears to be set to 1240 bytes (1280 Path MTU - 40 bytes of IPv6 header), instead of 1232 (additionally taking into account the 8 bytes required by the IPv6 Fragmentation extension header). This in turn results in rather inefficient transmission, as every transmitted TCP segment now is split in two fragments containing 1232+8 bytes of payload. After this patch, all the outgoing packets that includes a Fragmentation header all are "atomic" or "non-fragmented" fragments, i.e., they both have Offset=0 and More Fragments=0. With help from David S. Miller Reported-by: Tore Anderson <tore@fud.no> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Maciej Żenczykowski <maze@google.com> Cc: Tom Herbert <therbert@google.com> Tested-by: Tore Anderson <tore@fud.no> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-27tipc: Enhance error checking of published namesAllan Stephens2-7/+4
Consolidates validation of scope and name sequence range values into a single routine where it applies both to local name publications and to name publications issued by other nodes in the network. This change means that the scope value for non-local publications is now validated and the name sequence range for local publications is now validated only once. Additionally, a publication attempt that fails validation now creates an entry in the system log file only if debugging capabilities have been enabled; this prevents the system log from being cluttered up with messages caused by a defective application or network node. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-04-27tipc: Create helper routine to delete unused name sequence structureAllan Stephens1-12/+15
Replaces two identical chunks of code that delete an unused name sequence structure from TIPC's name table with calls to a new routine that performs this operation. This change is cosmetic and doesn't impact the operation of TIPC. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-04-27tipc: remove redundant memset and stale comment from subscr.cAllan Stephens1-2/+0
Eliminate code to zero-out the main topology service structure, which is already zeroed-out. Get rid of a comment documenting a field of the main topology service structure that no longer exists. Both are cosmetic changes with no impact on runtime behaviour. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-04-27tipc: Optimize initialization of network topology serviceAllan Stephens1-1/+1
Initialization now occurs in the calling thread of control, rather than being deferred to the TIPC tasklet. With the current codebase, the deferral is no longer necessary. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-04-27tipc: Enhance re-initialization of network topology serviceAllan Stephens1-3/+0
Streamlines the job of re-initializing TIPC's network topology service when a node's network address is first assigned. Rather than destroying the topology server port and breaking its connections to existing subscribers, TIPC now simply lets the service continue running (since the change to the port identifier of each port used by the topology service no longer impacts the flow of messages between the service and its subscribers). This enhancement means that applications that utilize the topology service prior to the assignment of TIPC's network address no longer need to re-establish their subscriptions when the address is finally assigned. However, it is worth noting that any subsequent events for existing subscriptions report the new port identifier of the publishing port, rather than the original port identifier. (For example, a name that was previously reported as being published by <0.0.0:ref> may be subsequently withdrawn by <Z.C.N:ref>.) This doesn't impact any of the existing known userspace in tipc-utils, since (a) TIPC continues to treat references to the original port ID correctly and (b) normal use cases assign an address before active use. However if there does happen to be some rare/custom application out there that was relying on this, they can simply bypass the enhancement by issuing a subscription to {0,0} and break its connection to the topology service, if an associated withdrawal event occurs. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-04-27tipc: Optimize termination of configuration serviceAllan Stephens1-4/+2
Termination no longer tests to see if the configuration service port was successfully created or not. In the unlikely event that the port was not created, attempting to delete the non-existent port is detected gracefully and causes no harm. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-04-27tipc: Optimize initialization of configuration serviceAllan Stephens1-1/+1
Initialization now occurs in the calling thread of control, rather than being deferred to the TIPC tasklet. With the current codebase, the deferral is no longer necessary. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-04-27tipc: Optimize re-initialization of configuration serviceAllan Stephens3-2/+17
Streamlines the job of re-initializing TIPC's configuration service when a node's network address is first assigned. Rather than destroying the configuration server port and then recreating it, TIPC now simply withdraws the existing {0,<0.0.0>} name publication and creates a new {0,<Z.C.N>} name publication that identifies the node's network address to interested subscribers. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-04-26Merge branch 'for-davem' of ↵David S. Miller15-118/+229
git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next