- 04 8月, 2015 1 次提交
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由 Robert Shearman 提交于
lwtunnel encap is applied for forwarded packets, but not for locally-generated packets. This is because the output function is not overridden in __mkroute_output, unlike it is in __mkroute_input. The lwtunnel state is correctly set on the rth through the call to rt_set_nexthop, so all that needs to be done is to override the dst output function to be lwtunnel_output if there is lwtunnel state present and it requires output redirection. Signed-off-by: NRobert Shearman <rshearma@brocade.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 30 7月, 2015 1 次提交
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由 Tom Herbert 提交于
This patch creates sk_set_txhash and eliminates protocol specific inet_set_txhash and ip6_set_txhash. sk_set_txhash simply sets a random number instead of performing flow dissection. sk_set_txash is also allowed to be called multiple times for the same socket, we'll need this when redoing the hash for negative routing advice. Signed-off-by: NTom Herbert <tom@herbertland.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 29 7月, 2015 2 次提交
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由 Eric Dumazet 提交于
When arp is off on a device, and ioctl(SIOCGARP) is queried, a buggy answer is given with MAC address of the device, instead of the mac address of the destination/gateway. We filter out NUD_NOARP neighbours for /proc/net/arp, we must do the same for SIOCGARP ioctl. Tested: lpaa23:~# ./arp 10.246.7.190 MAC=00:01:e8:22:cb:1d // correct answer lpaa23:~# ip link set dev eth0 arp off lpaa23:~# cat /proc/net/arp # check arp table is now 'empty' IP address HW type Flags HW address Mask Device lpaa23:~# ./arp 10.246.7.190 MAC=00:1a:11:c3:0d:7f // buggy answer before patch (this is eth0 mac) After patch : lpaa23:~# ip link set dev eth0 arp off lpaa23:~# ./arp 10.246.7.190 ioctl(SIOCGARP) failed: No such device or address Signed-off-by: NEric Dumazet <edumazet@google.com> Reported-by: NVytautas Valancius <valas@google.com> Cc: Willem de Bruijn <willemb@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 David Ward 提交于
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: NDavid Ward <david.ward@ll.mit.edu> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 28 7月, 2015 1 次提交
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由 Alexander Duyck 提交于
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: NDavid Ahern <dsa@cumulusnetworks.com> Signed-off-by: NAlexander Duyck <alexander.h.duyck@redhat.com> Tested-by: NDavid Ahern <dsa@cumulusnetworks.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 27 7月, 2015 8 次提交
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由 Eric Dumazet 提交于
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 a0ea700e ("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: NEric Dumazet <edumazet@google.com> Signed-off-by: NYuchung Cheng <ycheng@google.com> Cc: Neal Cardwell <ncardwell@google.com> Acked-by: NNeal Cardwell <ncardwell@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Sabrina Dubroca 提交于
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=1205258Reported-by: NEnrico Scholz <rh-bugzilla@ensc.de> Reported-by: NDan Searle <dan@censornet.com> Signed-off-by: NSabrina Dubroca <sd@queasysnail.net> Acked-by: NEric Dumazet <edumazet@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Nicolas Dichtel 提交于
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: NNicolas Dichtel <nicolas.dichtel@6wind.com> Acked-by: NThomas Graf <tgraf@suug.ch> Acked-by: NRoopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Nikolay Aleksandrov 提交于
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: NFrank Schreuder <fschreuder@transip.nl> Signed-off-by: NNikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: NFlorian Westphal <fw@strlen.de> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Florian Westphal 提交于
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: NFrank Schreuder <fschreuder@transip.nl> Signed-off-by: NFlorian Westphal <fw@strlen.de> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Florian Westphal 提交于
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: NFrank Schreuder <fschreuder@transip.nl> Signed-off-by: NFlorian Westphal <fw@strlen.de> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Florian Westphal 提交于
commit 65ba1f1e ("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: b13d3cbf ("inet: frag: move eviction of queues to work queue") Reported-by: NJohan Schuijt <johan@transip.nl> Tested-by: NFrank Schreuder <fschreuder@transip.nl> Signed-off-by: NNikolay Alexandrov <nikolay@cumulusnetworks.com> Signed-off-by: NFlorian Westphal <fw@strlen.de> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Julian Anastasov 提交于
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: NFlorian Westphal <fw@strlen.de> Signed-off-by: NJulian Anastasov <ja@ssi.bg> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 25 7月, 2015 2 次提交
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由 Julian Anastasov 提交于
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: NHagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: NJulian Anastasov <ja@ssi.bg> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Julian Anastasov 提交于
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: 79e5ad2c ("fib_trie: Remove leaf_info") Signed-off-by: NJulian Anastasov <ja@ssi.bg> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 23 7月, 2015 1 次提交
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由 Thomas Graf 提交于
Convert the module_init() to a invocation from inet_init() since ip_tunnel_core is part of the INET built-in. Fixes: 3093fbe7 ("route: Per route IP tunnel metadata via lightweight tunnel") Signed-off-by: NThomas Graf <tgraf@suug.ch> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 22 7月, 2015 11 次提交
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由 Rick Jones 提交于
Track success and failure of TCP PMTU probing. Signed-off-by: NRick Jones <rick.jones2@hp.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Eric Dumazet 提交于
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: 095dc8e0 ("tcp: fix/cleanup inet_ehash_locks_alloc()") Reported-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NEric Dumazet <edumazet@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Thomas Graf 提交于
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: NThomas Graf <tgraf@suug.ch> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Thomas Graf 提交于
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: NThomas Graf <tgraf@suug.ch> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Thomas Graf 提交于
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: NThomas Graf <tgraf@suug.ch> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Thomas Graf 提交于
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: NThomas Graf <tgraf@suug.ch> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Thomas Graf 提交于
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: NThomas Graf <tgraf@suug.ch> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Thomas Graf 提交于
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: NJulian Anastasov <ja@ssi.bg> Signed-off-by: NThomas Graf <tgraf@suug.ch> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Roopa Prabhu 提交于
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: NRoopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Roopa Prabhu 提交于
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: NRoopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Edward Hyunkoo Jee 提交于
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: 7736d33f ("packet: Add pre-defragmentation support for ipv4 fanouts.") Signed-off-by: NEdward Hyunkoo Jee <edjee@google.com> Signed-off-by: NEric Dumazet <edumazet@google.com> Cc: Willem de Bruijn <willemb@google.com> Cc: Jerry Chu <hkchu@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 16 7月, 2015 2 次提交
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由 Eric Dumazet 提交于
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: NEric Dumazet <edumazet@google.com> Acked-by: NHerbert Xu <herbert@gondor.apana.org.au> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Yuchung Cheng 提交于
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: NYuchung Cheng <ycheng@google.com> Signed-off-by: NNeal Cardwell <ncardwell@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 12 7月, 2015 1 次提交
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由 Florian Westphal 提交于
This reverts commit 3cc49492. 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: NFlorian Westphal <fw@strlen.de> Acked-by: NEric Dumazet <edumazet@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 11 7月, 2015 1 次提交
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由 Phil Sutter 提交于
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: NPhil Sutter <phil@nwl.cc> Cc: Eric Dumazet <edumazet@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 10 7月, 2015 9 次提交
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由 Eric Dumazet 提交于
After commit 900f65d3 ("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: NEric Dumazet <edumazet@google.com> Cc: Neal Cardwell <ncardwell@google.com> Acked-by: NNeal Cardwell <ncardwell@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Masatake YAMATO 提交于
flags local variable in __mkroute_input is not used as a variable. Signed-off-by: NMasatake YAMATO <yamato@redhat.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Tom Herbert 提交于
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: NTom Herbert <tom@herbertland.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Eric Dumazet 提交于
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: NEric Dumazet <edumazet@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Eric Dumazet 提交于
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 13475a30 ("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: NEric Dumazet <edumazet@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Yuchung Cheng 提交于
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: NYuchung Cheng <ycheng@google.com> Signed-off-by: NNeal Cardwell <ncardwell@google.com> Signed-off-by: NEric Dumazet <edumazet@google.com> Signed-off-by: NNandita Dukkipati <nanditad@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Yuchung Cheng 提交于
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: NYuchung Cheng <ycheng@google.com> Signed-off-by: NNeal Cardwell <ncardwell@google.com> Signed-off-by: NEric Dumazet <edumazet@google.com> Signed-off-by: NNandita Dukkipati <nanditad@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Yuchung Cheng 提交于
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: NYuchung Cheng <ycheng@google.com> Signed-off-by: NNeal Cardwell <ncardwell@google.com> Signed-off-by: NEric Dumazet <edumazet@google.com> Signed-off-by: NNandita Dukkipati <nanditad@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Jon Maxwell 提交于
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: NJon Maxwell <jmaxwell37@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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