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2015-07-28net/ipv4: suppress NETDEV_UP notification on address lifetime updateDavid Ward
This notification causes the FIB to be updated, which is not needed because the address already exists, and more importantly it may undo intentional changes that were made to the FIB after the address was originally added. (As a point of comparison, when an address becomes deprecated because its preferred lifetime expired, a notification on this chain is not generated.) The motivation for this commit is fixing an incompatibility between DHCP clients which set and update the address lifetime according to the lease, and a commercial VPN client which replaces kernel routes in a way that outbound traffic is sent only through the tunnel (and disconnects if any further route changes are detected via netlink). Signed-off-by: David Ward <david.ward@ll.mit.edu> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-27fib_trie: Drop unnecessary calls to leaf_pull_suffixAlexander Duyck
It was reported that update_suffix was taking a long time on systems where a large number of leaves were attached to a single node. As it turns out fib_table_flush was calling update_suffix for each leaf that didn't have all of the aliases stripped from it. As a result, on this large node removing one leaf would result in us calling update_suffix for every other leaf on the node. The fix is to just remove the calls to leaf_pull_suffix since they are redundant as we already have a call in resize that will go through and update the suffix length for the node before we exit out of fib_table_flush or fib_table_flush_external. Reported-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com> Tested-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-27tcp: tso: allow deferring under reordering stateEric Dumazet
While doing experiments with reordering resilience, we found linux senders were not able to send at full speed under reordering, because every incoming SACK was releasing one MSS. This patch removes the limitation, as we did for CWR state in commit a0ea700e409 ("tcp: tso: allow CA_CWR state in tcp_tso_should_defer()") Neal Cardwell had a concern about limited transmit so Yuchung conducted experiments on GFE and found nothing worth adding an extra check on fast path : if (icsk->icsk_ca_state == TCP_CA_Disorder && tcp_sk(sk)->reordering == sysctl_tcp_reordering) goto send_now; Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Cc: Neal Cardwell <ncardwell@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-27tcp: fix recv with flags MSG_WAITALL | MSG_PEEKSabrina Dubroca
Currently, tcp_recvmsg enters a busy loop in sk_wait_data if called with flags = MSG_WAITALL | MSG_PEEK. sk_wait_data waits for sk_receive_queue not empty, but in this case, the receive queue is not empty, but does not contain any skb that we can use. Add a "last skb seen on receive queue" argument to sk_wait_data, so that it sleeps until the receive queue has new skbs. Link: https://bugzilla.kernel.org/show_bug.cgi?id=99461 Link: https://sourceware.org/bugzilla/show_bug.cgi?id=18493 Link: https://bugzilla.redhat.com/show_bug.cgi?id=1205258 Reported-by: Enrico Scholz <rh-bugzilla@ensc.de> Reported-by: Dan Searle <dan@censornet.com> Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-27lwtunnel: change prototype of lwtunnel_state_get()Nicolas Dichtel
It saves some lines and simplify a bit the code when the state is returning by this function. It's also useful to handle a NULL entry. To avoid too long lines, I've also renamed lwtunnel_state_get() and lwtunnel_state_put() to lwtstate_get() and lwtstate_put(). CC: Thomas Graf <tgraf@suug.ch> CC: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Acked-by: Thomas Graf <tgraf@suug.ch> Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-26inet: frags: remove INET_FRAG_EVICTED and use list_evictor for the testNikolay Aleksandrov
We can simply remove the INET_FRAG_EVICTED flag to avoid all the flags race conditions with the evictor and use a participation test for the evictor list, when we're at that point (after inet_frag_kill) in the timer there're 2 possible cases: 1. The evictor added the entry to its evictor list while the timer was waiting for the chainlock or 2. The timer unchained the entry and the evictor won't see it In both cases we should be able to see list_evictor correctly due to the sync on the chainlock. Joint work with Florian Westphal. Tested-by: Frank Schreuder <fschreuder@transip.nl> Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-26inet: frag: don't wait for timer deletion when evictingFlorian Westphal
Frank reports 'NMI watchdog: BUG: soft lockup' errors when load is high. Instead of (potentially) unbounded restarts of the eviction process, just skip to the next entry. One caveat is that, when a netns is exiting, a timer may still be running by the time inet_evict_bucket returns. We use the frag memory accounting to wait for outstanding timers, so that when we free the percpu counter we can be sure no running timer will trip over it. Reported-and-tested-by: Frank Schreuder <fschreuder@transip.nl> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-26inet: frag: change *_frag_mem_limit functions to take netns_frags as argumentFlorian Westphal
Followup patch will call it after inet_frag_queue was freed, so q->net doesn't work anymore (but netf = q->net; free(q); mem_limit(netf) would). Tested-by: Frank Schreuder <fschreuder@transip.nl> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-26inet: frag: don't re-use chainlist for evictorFlorian Westphal
commit 65ba1f1ec0eff ("inet: frags: fix a race between inet_evict_bucket and inet_frag_kill") describes the bug, but the fix doesn't work reliably. Problem is that ->flags member can be set on other cpu without chainlock being held by that task, i.e. the RMW-Cycle can clear INET_FRAG_EVICTED bit after we put the element on the evictor private list. We can crash when walking the 'private' evictor list since an element can be deleted from list underneath the evictor. Join work with Nikolay Alexandrov. Fixes: b13d3cbfb8e8 ("inet: frag: move eviction of queues to work queue") Reported-by: Johan Schuijt <johan@transip.nl> Tested-by: Frank Schreuder <fschreuder@transip.nl> Signed-off-by: Nikolay Alexandrov <nikolay@cumulusnetworks.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-26ipv4: be more aggressive when probing alternative gatewaysJulian Anastasov
Currently, we do not notice if new alternative gateways are added. We can do it by checking for present neigh entry. Also, gateways that are currently probed (NUD_INCOMPLETE) can be skipped from round-robin probing. Suggested-by: Florian Westphal <fw@strlen.de> Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-24ipv4: consider TOS in fib_select_defaultJulian Anastasov
fib_select_default considers alternative routes only when res->fi is for the first alias in res->fa_head. In the common case this can happen only when the initial lookup matches the first alias with highest TOS value. This prevents the alternative routes to require specific TOS. This patch solves the problem as follows: - routes that require specific TOS should be returned by fib_select_default only when TOS matches, as already done in fib_table_lookup. This rule implies that depending on the TOS we can have many different lists of alternative gateways and we have to keep the last used gateway (fa_default) in first alias for the TOS instead of using single tb_default value. - as the aliases are ordered by many keys (TOS desc, fib_priority asc), we restrict the possible results to routes with matching TOS and lowest metric (fib_priority) and routes that match any TOS, again with lowest metric. For example, packet with TOS 8 can not use gw3 (not lowest metric), gw4 (different TOS) and gw6 (not lowest metric), all other gateways can be used: tos 8 via gw1 metric 2 <--- res->fa_head and res->fi tos 8 via gw2 metric 2 tos 8 via gw3 metric 3 tos 4 via gw4 tos 0 via gw5 tos 0 via gw6 metric 1 Reported-by: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-24ipv4: fib_select_default should match the prefixJulian Anastasov
fib_trie starting from 4.1 can link fib aliases from different prefixes in same list. Make sure the alternative gateways are in same table and for same prefix (0) by checking tb_id and fa_slen. Fixes: 79e5ad2ceb00 ("fib_trie: Remove leaf_info") Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-23ip_tunnel: Call ip_tunnel_core_init() from inet_init()Thomas Graf
Convert the module_init() to a invocation from inet_init() since ip_tunnel_core is part of the INET built-in. Fixes: 3093fbe7ff4 ("route: Per route IP tunnel metadata via lightweight tunnel") Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Conflicts: net/bridge/br_mdb.c br_mdb.c conflict was a function call being removed to fix a bug in 'net' but whose signature was changed in 'net-next'. Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-21net: track success and failure of TCP PMTU probingRick Jones
Track success and failure of TCP PMTU probing. Signed-off-by: Rick Jones <rick.jones2@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-21tcp: suppress a division by zero warningEric Dumazet
Andrew Morton reported following warning on one ARM build with gcc-4.4 : net/ipv4/inet_hashtables.c: In function 'inet_ehash_locks_alloc': net/ipv4/inet_hashtables.c:617: warning: division by zero Even guarded with a test on sizeof(spinlock_t), compiler does not like current construct on a !CONFIG_SMP build. Remove the warning by using a temporary variable. Fixes: 095dc8e0c368 ("tcp: fix/cleanup inet_ehash_locks_alloc()") Reported-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-21fib: Add fib rule match on tunnel idThomas Graf
This add the ability to select a routing table based on the tunnel id which allows to maintain separate routing tables for each virtual tunnel network. ip rule add from all tunnel-id 100 lookup 100 ip rule add from all tunnel-id 200 lookup 200 A new static key controls the collection of metadata at tunnel level upon demand. Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-21route: Per route IP tunnel metadata via lightweight tunnelThomas Graf
This introduces a new IP tunnel lightweight tunnel type which allows to specify IP tunnel instructions per route. Only IPv4 is supported at this point. Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-21route: Extend flow representation with tunnel keyThomas Graf
Add a new flowi_tunnel structure which is a subset of ip_tunnel_key to allow routes to match on tunnel metadata. For now, the tunnel id is added to flowi_tunnel which allows for routes to be bound to specific virtual tunnels. Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-21arp: Inherit metadata dst when creating ARP requestsThomas Graf
If output device wants to see the dst, inherit the dst of the original skb and pass it on to generate the ARP request. Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-21dst: Metadata destinationsThomas Graf
Introduces a new dst_metadata which enables to carry per packet metadata between forwarding and processing elements via the skb->dst pointer. The structure is set up to be a union. Thus, each separate type of metadata requires its own dst instance. If demand arises to carry multiple types of metadata concurrently, metadata dst entries can be made stackable. The metadata dst entry is refcnt'ed as expected for now but a non reference counted use is possible if the reference is forced before queueing the skb. In order to allow allocating dsts with variable length, the existing dst_alloc() is split into a dst_alloc() and dst_init() function. The existing dst_init() function to initialize the subsystem is being renamed to dst_subsys_init() to make it clear what is what. The check before ip_route_input() is changed to ignore metadata dsts and drop the dst inside the routing function thus allowing to interpret metadata in a later commit. Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-21icmp: Don't leak original dst into ip_route_input()Thomas Graf
ip_route_input() unconditionally overwrites the dst. Hide the original dst attached to the skb by calling skb_dst_set(skb, NULL) prior to ip_route_input(). Reported-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-21ipv4: redirect dst output to lwtunnel outputRoopa Prabhu
For input routes with tunnel encap state this patch redirects dst output functions to lwtunnel_output which later resolves to the corresponding lwtunnel output function. This has been tested to work with mpls ip tunnels. Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-21ipv4: support for fib route lwtunnel encap attributesRoopa Prabhu
This patch adds support in ipv4 fib functions to parse user provided encap attributes and attach encap state data to fib_nh and rtable. Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-21inet: frags: fix defragmented packet's IP header for af_packetEdward Hyunkoo Jee
When ip_frag_queue() computes positions, it assumes that the passed sk_buff does not contain L2 headers. However, when PACKET_FANOUT_FLAG_DEFRAG is used, IP reassembly functions can be called on outgoing packets that contain L2 headers. Also, IPv4 checksum is not corrected after reassembly. Fixes: 7736d33f4262 ("packet: Add pre-defragmentation support for ipv4 fanouts.") Signed-off-by: Edward Hyunkoo Jee <edjee@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Willem de Bruijn <willemb@google.com> Cc: Jerry Chu <hkchu@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-15ipv6: lock socket in ip6_datagram_connect()Eric Dumazet
ip6_datagram_connect() is doing a lot of socket changes without socket being locked. This looks wrong, at least for udp_lib_rehash() which could corrupt lists because of concurrent udp_sk(sk)->udp_portaddr_hash accesses. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-15tcp: don't use F-RTO on non-recurring timeoutsYuchung Cheng
Currently F-RTO may repeatedly send new data packets on non-recurring timeouts in CA_Loss mode. This is a bug because F-RTO (RFC5682) should only be used on either new recovery or recurring timeouts. This exacerbates the recovery progress during frequent timeout & repair, because we prioritize sending new data packets instead of repairing the holes when the bandwidth is already scarce. Fix it by correcting the test of a new recovery episode. Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-15netfilter: xtables: remove __pure annotationFlorian Westphal
sparse complains: ip_tables.c:361:27: warning: incorrect type in assignment (different modifiers) ip_tables.c:361:27: expected struct ipt_entry *[assigned] e ip_tables.c:361:27: got struct ipt_entry [pure] * doesn't change generated code. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-07-15netfilter: add and use jump label for xt_teeFlorian Westphal
Don't bother testing if we need to switch to alternate stack unless TEE target is used. Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-07-15netfilter: xtables: don't save/restore jumpstack offsetFlorian Westphal
In most cases there is no reentrancy into ip/ip6tables. For skbs sent by REJECT or SYNPROXY targets, there is one level of reentrancy, but its not relevant as those targets issue an absolute verdict, i.e. the jumpstack can be clobbered since its not used after the target issues absolute verdict (ACCEPT, DROP, STOLEN, etc). So the only special case where it is relevant is the TEE target, which returns XT_CONTINUE. This patch changes ip(6)_do_table to always use the jump stack starting from 0. When we detect we're operating on an skb sent via TEE (percpu nf_skb_duplicated is 1) we switch to an alternate stack to leave the original one alone. Since there is no TEE support for arptables, it doesn't need to test if tee is active. The jump stack overflow tests are no longer needed as well -- since ->stacksize is the largest call depth we cannot exceed it. A much better alternative to the external jumpstack would be to just declare a jumps[32] stack on the local stack frame, but that would mean we'd have to reject iptables rulesets that used to work before. Another alternative would be to start rejecting rulesets with a larger call depth, e.g. 1000 -- in this case it would be feasible to allocate the entire stack in the percpu area which would avoid one dereference. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-07-15netfilter: xtables: compute exact size needed for jumpstackFlorian Westphal
The {arp,ip,ip6tables} jump stack is currently sized based on the number of user chains. However, its rather unlikely that every user defined chain jumps to the next, so lets use the existing loop detection logic to also track the chain depths. The stacksize is then set to the largest chain depth seen. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-07-13Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Conflicts: net/bridge/br_mdb.c Minor conflict in br_mdb.c, in 'net' we added a memset of the on-stack 'ip' variable whereas in 'net-next' we assign a new member 'vid'. Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-11Revert "ipv4: use skb coalescing in defragmentation"Florian Westphal
This reverts commit 3cc4949269e01f39443d0fcfffb5bc6b47878d45. There is nothing wrong with coalescing during defragmentation, it reduces truesize overhead and simplifies things for the receiving socket (no fraglist walk needed). However, it also destroys geometry of the original fragments. While that doesn't cause any breakage (we make sure to not exceed largest original size) ip_do_fragment contains a 'fastpath' that takes advantage of a present frag list and results in fragments that (in most cases) match what was received. In case its needed the coalescing could be done later, when we're sure the skb is not forwarded. But discussion during NFWS resulted in 'lets just remove this for now'. Cc: Eric Dumazet <edumazet@google.com> Signed-off-by: Florian Westphal <fw@strlen.de> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-10net: inet_diag: always export IPV6_V6ONLY sockopt for listening socketsPhil Sutter
Reconsidering my commit 20462155 "net: inet_diag: export IPV6_V6ONLY sockopt", I am not happy with the limitations it causes for socket analysing code in userspace. Exporting the value only if it is set makes it hard for userspace to decide whether the option is not set or the kernel does not support exporting the option at all. >From an auditor's perspective, the interesting question for listening AF_INET6 sockets is: "Does it NOT have IPV6_V6ONLY set?" Because it is the unexpected case. This patch allows to answer this question reliably. Signed-off-by: Phil Sutter <phil@nwl.cc> Cc: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-09tcp: do not export tcp_init_xmit_timers()Eric Dumazet
After commit 900f65d361d3 ("tcp: move duplicate code from tcp_v4_init_sock()/tcp_v6_init_sock()"), we no longer need to export tcp_init_xmit_timers() Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Neal Cardwell <ncardwell@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-09route: remove unsed variable in __mkroute_inputMasatake YAMATO
flags local variable in __mkroute_input is not used as a variable. Signed-off-by: Masatake YAMATO <yamato@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-09ipv6: Nonlocal bindTom Herbert
Add support to allow non-local binds similar to how this was done for IPv4. Non-local binds are very useful in emulating the Internet in a box, etc. This add the ip_nonlocal_bind sysctl under ipv6. Testing: Set up nonlocal binding and receive routing on a host, e.g.: ip -6 rule add from ::/0 iif eth0 lookup 200 ip -6 route add local 2001:0:0:1::/64 dev lo proto kernel scope host table 200 sysctl -w net.ipv6.ip_nonlocal_bind=1 Set up routing to 2001:0:0:1::/64 on peer to go to first host ping6 -I 2001:0:0:1::1 peer-address -- to verify Signed-off-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-09inet: inet_twsk_deschedule factorizationEric Dumazet
inet_twsk_deschedule() calls are followed by inet_twsk_put(). Only particular case is in inet_twsk_purge() but there is no point to defer the inet_twsk_put() after re-enabling BH. Lets rename inet_twsk_deschedule() to inet_twsk_deschedule_put() and move the inet_twsk_put() inside. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-09inet: simplify timewait refcountingEric Dumazet
timewait sockets have a complex refcounting logic. Once we realize it should be similar to established and syn_recv sockets, we can use sk_nulls_del_node_init_rcu() and remove inet_twsk_unhash() In particular, deferred inet_twsk_put() added in commit 13475a30b66cd ("tcp: connect() race with timewait reuse") looks unecessary : When removing a timewait socket from ehash or bhash, caller must own a reference on the socket anyway. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-09tcp: update congestion state first before raising cwndYuchung Cheng
The congestion state and cwnd can be updated in the wrong order. For example, upon receiving a dubious ACK, we incorrectly raise the cwnd first (tcp_may_raise_cwnd()/tcp_cong_avoid()) because the state is still Open, then enter recovery state to reduce cwnd. For another example, if the ACK indicates spurious timeout or retransmits, we first revert the cwnd reduction and congestion state back to Open state. But we don't raise the cwnd even though the ACK does not indicate any congestion. To fix this problem we should first call tcp_fastretrans_alert() to process the dubious ACK and update the congestion state, then call tcp_may_raise_cwnd() that raises cwnd based on the current state. Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Nandita Dukkipati <nanditad@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-09tcp: do not slow start when cwnd equals ssthreshYuchung Cheng
In the original design slow start is only used to raise cwnd when cwnd is stricly below ssthresh. It makes little sense to slow start when cwnd == ssthresh: especially when hystart has set ssthresh in the initial ramp, or after recovery when cwnd resets to ssthresh. Not doing so will also help reduce the buffer bloat slightly. Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Nandita Dukkipati <nanditad@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-09tcp: add tcp_in_slow_start helperYuchung Cheng
Add a helper to test the slow start condition in various congestion control modules and other places. This is to prepare a slight improvement in policy as to exactly when to slow start. Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Nandita Dukkipati <nanditad@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-09tcp: v1 always send a quick ack when quickacks are enabledJon Maxwell
V1 of this patch contains Eric Dumazet's suggestion to move the per dst RTAX_QUICKACK check into tcp_in_quickack_mode(). Thanks Eric. I ran some tests and after setting the "ip route change quickack 1" knob there were still many delayed ACKs sent. This occured because when icsk_ack.quick=0 the !icsk_ack.pingpong value is subsequently ignored as tcp_in_quickack_mode() checks both these values. The condition for a quick ack to trigger requires that both icsk_ack.quick != 0 and icsk_ack.pingpong=0. Currently only icsk_ack.pingpong is controlled by the knob. But the icsk_ack.quick value changes dynamically depending on heuristics. The crux of the matter is that delayed acks still cannot be entirely disabled even with the RTAX_QUICKACK per dst knob enabled. This patch ensures that a quick ack is always sent when the RTAX_QUICKACK per dst knob is turned on. The "ip route change quickack 1" knob was recently added to enable quickacks. It was modeled around the TCP_QUICKACK setsockopt() option. This issue is that even with "ip route change quickack 1" enabled we still see delayed ACKs under some conditions. It would be nice to be able to completely disable delayed ACKs. Here is an example: # netstat -s|grep dela 3 delayed acks sent For all routes enable the knob # ip route change quickack 1 Generate some traffic across a slow link and we still see the delayed acks. # netstat -s|grep dela 106 delayed acks sent 1 delayed acks further delayed because of locked socket The issue is that both the "ip route change quickack 1" knob and the TCP_QUICKACK option set the icsk_ack.pingpong variable to 0. However at the business end in the __tcp_ack_snd_check() routine, tcp_in_quickack_mode() checks that both icsk_ack.quick != 0 and icsk_ack.pingpong=0 in order to trigger a quickack. As icsk_ack.quick is determined by heuristics it can be 0. When that occurs the icsk_ack.pingpong value is ignored and a delayed ACK is sent regardless. This patch moves the RTAX_QUICKACK per dst check into the tcp_in_quickack_mode() routine which ensures that a quickack is always sent when the quickack knob is enabled for that dst. Signed-off-by: Jon Maxwell <jmaxwell37@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-09Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nfDavid S. Miller
Pablo Neira Ayuso says: ==================== Netfilter fixes for net The following patchset contains Netfilter fixes for your net tree. This batch mostly comes with patches to address fallout from the previous merge window cycle, they are: 1) Use entry->state.hook_list from nf_queue() instead of the global nf_hooks which is not valid when used from NFPROTO_NETDEV, this should cause no problems though since we have no userspace queueing for that family, but let's fix this now for the sake of correctness. Patch from Eric W. Biederman. 2) Fix compilation breakage in bridge netfilter if CONFIG_NF_DEFRAG_IPV4 is not set, from Bernhard Thaler. 3) Use percpu jumpstack in arptables too, now that there's a single copy of the rule blob we can't store the return address there anymore. Patch from Florian Westphal. 4) Fix a skb leak in the xmit path of bridge netfilter, problem there since 2.6.37 although it should be not possible to hit invalid traffic there, also from Florian. 5) Eric Leblond reports that when loading a large ruleset with many missing modules after a fresh boot, nf_tables can take long time commit it. Fix this by processing the full batch until the end, even on missing modules, then abort only once and restart processing. 6) Add bridge netfilter files to the MAINTAINER files. 7) Fix a net_device refcount leak in the new IPV6 bridge netfilter code, from Julien Grall. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-08ipv4: add support for linkdown sysctl to netconfAndy Gospodarek
This kernel patch exports the value of the new ignore_routes_with_linkdown via netconf. v2: changes to notify userspace via netlink when sysctl values change and proposed for 'net' since this could be considered a bugfix Signed-off-by: Andy Gospodarek <gospo@cumulusnetworks.com> Suggested-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-08ip_tunnel: fix ipv4 pmtu check to honor inner ip header dfTimo Teräs
Frag needed should be sent only if the inner header asked to not fragment. Currently fragmentation is broken if the tunnel has df set, but df was not asked in the original packet. The tunnel's df needs to be still checked to update internally the pmtu cache. Commit 23a3647bc4f93bac broke it, and this commit fixes the ipv4 df check back to the way it was. Fixes: 23a3647bc4f93bac ("ip_tunnels: Use skb-len to PMTU check.") Cc: Pravin B Shelar <pshelar@nicira.com> Signed-off-by: Timo Teräs <timo.teras@iki.fi> Acked-by: Pravin B Shelar <pshelar@nicira.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-08tcp: PRR uses CRB mode by default and SS mode conditionallyYuchung Cheng
PRR slow start is often too aggressive especially when drops are caused by traffic policers. The policers mainly use token bucket to enforce the rate so sending (twice) faster than the delivery rate causes excessive drops. This patch changes PRR to the conservative reduction bound (CRB) mode in RFC 6937 by default. CRB follows the packet conservation rule to send at most the delivery rate by default. But if many packets are lost and the pipe is empty, CRB may take N round trips to repair N losses. We conditionally turn on slow start mode if all these conditions are made to speed up the recovery: 1) on the second round or later in recovery 2) retransmission sent in the previous round is delivered on this ACK 3) no retransmission is marked lost on this ACK By using packet conservation by default, this change reduces the loss retransmits signicantly on networks that deploy traffic policers, up to 20% reduction of overall loss rate. Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Nandita Dukkipati <nanditad@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-08tcp: reduce cwnd if retransmit is lost in CA_LossYuchung Cheng
If the retransmission in CA_Loss is lost again, we should not continue to slow start or raise cwnd in congestion avoidance mode. Instead we should enter fast recovery and use PRR to reduce cwnd, following the principle in RFC5681: "... or the loss of a retransmission, should be taken as two indications of congestion and, therefore, cwnd (and ssthresh) MUST be lowered twice in this case." This is especially important to reduce loss when the CA_Loss state was caused by a traffic policer dropping the entire inflight. The CA_Loss state has a problem where a loss of L packets causes the sender to send a burst of L packets. So a policer that's dropping most packets in a given RTT can cause a huge retransmit storm. By contrast, PRR includes logic to bound the number of outbound packets that result from a given ACK. So switching to CA_Recovery on lost retransmits in CA_Loss avoids this retransmit storm problem when in CA_Loss. Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Nandita Dukkipati <nanditad@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-02Merge tag 'module_init-alternate_initcall-v4.1-rc8' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux Pull module_init replacement part two from Paul Gortmaker: "Replace module_init with appropriate alternate initcall in non modules. This series converts non-modular code that is using the module_init() call to hook itself into the system to instead use one of our alternate priority initcalls. Unlike the previous series that used device_initcall and hence was a runtime no-op, these commits change to one of the alternate initcalls, because (a) we have them and (b) it seems like the right thing to do. For example, it would seem logical to use arch_initcall for arch specific setup code and fs_initcall for filesystem setup code. This does mean however, that changes in the init ordering will be taking place, and so there is a small risk that some kind of implicit init ordering issue may lie uncovered. But I think it is still better to give these ones sensible priorities than to just assign them all to device_initcall in order to exactly preserve the old ordering. Thad said, we have already made similar changes in core kernel code in commit c96d6660dc65 ("kernel: audit/fix non-modular users of module_init in core code") without any regressions reported, so this type of change isn't without precedent. It has also got the same local testing and linux-next coverage as all the other pull requests that I'm sending for this merge window have got. Once again, there is an unused module_exit function removal that shows up as an outlier upon casual inspection of the diffstat" * tag 'module_init-alternate_initcall-v4.1-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: x86: perf_event_intel_pt.c: use arch_initcall to hook in enabling x86: perf_event_intel_bts.c: use arch_initcall to hook in enabling mm/page_owner.c: use late_initcall to hook in enabling lib/list_sort: use late_initcall to hook in self tests arm: use subsys_initcall in non-modular pl320 IPC code powerpc: don't use module_init for non-modular core hugetlb code powerpc: use subsys_initcall for Freescale Local Bus x86: don't use module_init for non-modular core bootflag code netfilter: don't use module_init/exit in core IPV4 code fs/notify: don't use module_init for non-modular inotify_user code mm: replace module_init usages with subsys_initcall in nommu.c
2015-07-02netfilter: arptables: use percpu jumpstackFlorian Westphal
commit 482cfc318559 ("netfilter: xtables: avoid percpu ruleset duplication") Unlike ip and ip6tables, arp tables were never converted to use the percpu jump stack. It still uses the rule blob to store return address, which isn't safe anymore since we now share this blob among all processors. Because there is no TEE support for arptables, we don't need to cope with reentrancy, so we can use loocal variable to hold stack offset. Fixes: 482cfc318559 ("netfilter: xtables: avoid percpu ruleset duplication") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>