summaryrefslogtreecommitdiff
path: root/net/ipv4
AgeCommit message (Collapse)Author
2012-07-20tcp: improve latencies of timer triggered eventsEric Dumazet
Modern TCP stack highly depends on tcp_write_timer() having a small latency, but current implementation doesn't exactly meet the expectations. When a timer fires but finds the socket is owned by the user, it rearms itself for an additional delay hoping next run will be more successful. tcp_write_timer() for example uses a 50ms delay for next try, and it defeats many attempts to get predictable TCP behavior in term of latencies. Use the recently introduced tcp_release_cb(), so that the user owning the socket will call various handlers right before socket release. This will permit us to post a followup patch to address the tcp_tso_should_defer() syndrome (some deferred packets have to wait RTO timer to be transmitted, while cwnd should allow us to send them sooner) Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Tom Herbert <therbert@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Nandita Dukkipati <nanditad@google.com> Cc: H.K. Jerry Chu <hkchu@google.com> Cc: John Heffner <johnwheffner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-20tcp: fix ABC in tcp_slow_start()Eric Dumazet
When/if sysctl_tcp_abc > 1, we expect to increase cwnd by 2 if the received ACK acknowledges more than 2*MSS bytes, in tcp_slow_start() Problem is this RFC 3465 statement is not correctly coded, as the while () loop increases snd_cwnd one by one. Add a new variable to avoid this off-by one error. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Tom Herbert <therbert@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Nandita Dukkipati <nanditad@google.com> Cc: John Heffner <johnwheffner@gmail.com> Cc: Stephen Hemminger <shemminger@vyatta.com> Acked-by: Yuchung Cheng <ycheng@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-20tcp: use hash_32() in tcp_metricsEric Dumazet
Fix a missing roundup_pow_of_two(), since tcpmhash_entries is not guaranteed to be a power of two. Uses hash_32() instead of custom hash. tcpmhash_entries should be an unsigned int. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-20tcp: Return bool instead of int where appropriateVijay Subramanian
Applied to a set of static inline functions in tcp_input.c Signed-off-by: Vijay Subramanian <subramanian.vijay@gmail.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-19ipv4: Fix again the time difference calculationJulian Anastasov
Fix again the diff value in rt_bind_exception after collision of two latest patches, my original commit actually fixed the same problem. Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-19Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Conflicts: drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
2012-07-19net-tcp: Fast Open client - cookie-less modeYuchung Cheng
In trusted networks, e.g., intranet, data-center, the client does not need to use Fast Open cookie to mitigate DoS attacks. In cookie-less mode, sendmsg() with MSG_FASTOPEN flag will send SYN-data regardless of cookie availability. Signed-off-by: Yuchung Cheng <ycheng@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-19net-tcp: Fast Open client - detecting SYN-data dropsYuchung Cheng
On paths with firewalls dropping SYN with data or experimental TCP options, Fast Open connections will have experience SYN timeout and bad performance. The solution is to track such incidents in the cookie cache and disables Fast Open temporarily. Since only the original SYN includes data and/or Fast Open option, the SYN-ACK has some tell-tale sign (tcp_rcv_fastopen_synack()) to detect such drops. If a path has recurring Fast Open SYN drops, Fast Open is disabled for 2^(recurring_losses) minutes starting from four minutes up to roughly one and half day. sendmsg with MSG_FASTOPEN flag will succeed but it behaves as connect() then write(). Signed-off-by: Yuchung Cheng <ycheng@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-19net-tcp: Fast Open client - sendmsg(MSG_FASTOPEN)Yuchung Cheng
sendmsg() (or sendto()) with MSG_FASTOPEN is a combo of connect(2) and write(2). The application should replace connect() with it to send data in the opening SYN packet. For blocking socket, sendmsg() blocks until all the data are buffered locally and the handshake is completed like connect() call. It returns similar errno like connect() if the TCP handshake fails. For non-blocking socket, it returns the number of bytes queued (and transmitted in the SYN-data packet) if cookie is available. If cookie is not available, it transmits a data-less SYN packet with Fast Open cookie request option and returns -EINPROGRESS like connect(). Using MSG_FASTOPEN on connecting or connected socket will result in simlar errno like repeating connect() calls. Therefore the application should only use this flag on new sockets. The buffer size of sendmsg() is independent of the MSS of the connection. Signed-off-by: Yuchung Cheng <ycheng@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-19net-tcp: Fast Open client - receiving SYN-ACKYuchung Cheng
On receiving the SYN-ACK after SYN-data, the client needs to a) update the cached MSS and cookie (if included in SYN-ACK) b) retransmit the data not yet acknowledged by the SYN-ACK in the final ACK of the handshake. Signed-off-by: Yuchung Cheng <ycheng@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-19net-tcp: Fast Open client - sending SYN-dataYuchung Cheng
This patch implements sending SYN-data in tcp_connect(). The data is from tcp_sendmsg() with flag MSG_FASTOPEN (implemented in a later patch). The length of the cookie in tcp_fastopen_req, init'd to 0, controls the type of the SYN. If the cookie is not cached (len==0), the host sends data-less SYN with Fast Open cookie request option to solicit a cookie from the remote. If cookie is not available (len > 0), the host sends a SYN-data with Fast Open cookie option. If cookie length is negative, the SYN will not include any Fast Open option (for fall back operations). To deal with middleboxes that may drop SYN with data or experimental TCP option, the SYN-data is only sent once. SYN retransmits do not include data or Fast Open options. The connection will fall back to regular TCP handshake. Signed-off-by: Yuchung Cheng <ycheng@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-19net-tcp: Fast Open client - cookie cacheYuchung Cheng
With help from Eric Dumazet, add Fast Open metrics in tcp metrics cache. The basic ones are MSS and the cookies. Later patch will cache more to handle unfriendly middleboxes. Signed-off-by: Yuchung Cheng <ycheng@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-19net-tcp: Fast Open baseYuchung Cheng
This patch impelements the common code for both the client and server. 1. TCP Fast Open option processing. Since Fast Open does not have an option number assigned by IANA yet, it shares the experiment option code 254 by implementing draft-ietf-tcpm-experimental-options with a 16 bits magic number 0xF989. This enables global experiments without clashing the scarce(2) experimental options available for TCP. When the draft status becomes standard (maybe), the client should switch to the new option number assigned while the server supports both numbers for transistion. 2. The new sysctl tcp_fastopen 3. A place holder init function Signed-off-by: Yuchung Cheng <ycheng@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-19ipv4: tcp: remove per net tcp_sockEric Dumazet
tcp_v4_send_reset() and tcp_v4_send_ack() use a single socket per network namespace. This leads to bad behavior on multiqueue NICS, because many cpus contend for the socket lock and once socket lock is acquired, extra false sharing on various socket fields slow down the operations. To better resist to attacks, we use a percpu socket. Each cpu can run without contention, using appropriate memory (local node) Additional features : 1) We also mirror the queue_mapping of the incoming skb, so that answers use the same queue if possible. 2) Setting SOCK_USE_WRITE_QUEUE socket flag speedup sock_wfree() 3) We now limit the number of in-flight RST/ACK [1] packets per cpu, instead of per namespace, and we honor the sysctl_wmem_default limit dynamically. (Prior to this patch, sysctl_wmem_default value was copied at boot time, so any further change would not affect tcp_sock limit) [1] These packets are only generated when no socket was matched for the incoming packet. Reported-by: Bill Sommerfeld <wsommerfeld@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-19ipv4: use seqlock for nh_exceptionsJulian Anastasov
Use global seqlock for the nh_exceptions. Call fnhe_oldest with the right hash chain. Correct the diff value for dst_set_expires. v2: after suggestions from Eric Dumazet: * get rid of spin lock fnhe_lock, rearrange update_or_create_fnhe * continue daddr search in rt_bind_exception v3: * remove the daddr check before seqlock in rt_bind_exception * restart lookup in rt_bind_exception on detected seqlock change, as suggested by David Miller Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-19ipv4: Fix time difference calculation in rt_bind_exception().David S. Miller
Reported-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-19ipv4: fix address selection in fib_compute_spec_dstJulian Anastasov
ip_options_compile can be called for forwarded packets, make sure the specific-destionation address is a local one as specified in RFC 1812, 4.2.2.2 Addresses in Options Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-19ipv4: optimize fib_compute_spec_dst call in ip_options_echoJulian Anastasov
Move fib_compute_spec_dst at the only place where it is needed. Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-18ipv6: add ipv6_addr_hash() helperEric Dumazet
Introduce ipv6_addr_hash() helper doing a XOR on all bits of an IPv6 address, with an optimized x86_64 version. Use it in flow dissector, as suggested by Andrew McGregor, to reduce hash collision probabilities in fq_codel (and other users of flow dissector) Use it in ip6_tunnel.c and use more bit shuffling, as suggested by David Laight, as existing hash was ignoring most of them. Use it in sunrpc and use more bit shuffling, using hash_32(). Use it in net/ipv6/addrconf.c, using hash_32() as well. As a cleanup, use it in net/ipv4/tcp_metrics.c Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Andrew McGregor <andrewmcgr@gmail.com> Cc: Dave Taht <dave.taht@gmail.com> Cc: Tom Herbert <therbert@google.com> Cc: David Laight <David.Laight@ACULAB.COM> Cc: Joe Perches <joe@perches.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-18net/ipv4: VTI support new module for ip_vti.Saurabh
New VTI tunnel kernel module, Kconfig and Makefile changes. Signed-off-by: Saurabh Mohan <saurabh.mohan@vyatta.com> Reviewed-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-18net/ipv4: VTI support rx-path hook in xfrm4_mode_tunnel.Saurabh
Incorporated David and Steffen's comments. Add hook for rx-path xfmr4_mode_tunnel for VTI tunnel module. Signed-off-by: Saurabh Mohan <saurabh.mohan@vyatta.com> Reviewed-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-18tcp: refine SYN handling in tcp_validate_incomingEric Dumazet
Followup of commit 0c24604b68fc (tcp: implement RFC 5961 4.2) As reported by Vijay Subramanian, we should send a challenge ACK instead of a dup ack if a SYN flag is set on a packet received out of window. This permits the ratelimiting to work as intended, and to increase correct SNMP counters. Suggested-by: Vijay Subramanian <subramanian.vijay@gmail.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Vijay Subramanian <subramanian.vijay@gmail.com> Cc: Kiran Kumar Kella <kkiran@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-18cipso: don't follow a NULL pointer when setsockopt() is calledPaul Moore
As reported by Alan Cox, and verified by Lin Ming, when a user attempts to add a CIPSO option to a socket using the CIPSO_V4_TAG_LOCAL tag the kernel dies a terrible death when it attempts to follow a NULL pointer (the skb argument to cipso_v4_validate() is NULL when called via the setsockopt() syscall). This patch fixes this by first checking to ensure that the skb is non-NULL before using it to find the incoming network interface. In the unlikely case where the skb is NULL and the user attempts to add a CIPSO option with the _TAG_LOCAL tag we return an error as this is not something we want to allow. A simple reproducer, kindly supplied by Lin Ming, although you must have the CIPSO DOI #3 configure on the system first or you will be caught early in cipso_v4_validate(): #include <sys/types.h> #include <sys/socket.h> #include <linux/ip.h> #include <linux/in.h> #include <string.h> struct local_tag { char type; char length; char info[4]; }; struct cipso { char type; char length; char doi[4]; struct local_tag local; }; int main(int argc, char **argv) { int sockfd; struct cipso cipso = { .type = IPOPT_CIPSO, .length = sizeof(struct cipso), .local = { .type = 128, .length = sizeof(struct local_tag), }, }; memset(cipso.doi, 0, 4); cipso.doi[3] = 3; sockfd = socket(AF_INET, SOCK_DGRAM, 0); #define SOL_IP 0 setsockopt(sockfd, SOL_IP, IP_OPTIONS, &cipso, sizeof(struct cipso)); return 0; } CC: Lin Ming <mlin@ss.pku.edu.cn> Reported-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Paul Moore <pmoore@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-17ipv4: fix rcu splatEric Dumazet
free_nh_exceptions() should use rcu_dereference_protected(..., 1) since its called after one RCU grace period. Also add some const-ification in recent code. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-17ipv4: Fix nexthop exception hash computation.David S. Miller
Need to mask it with (FNHE_HASH_SIZE - 1). Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-17Merge branch 'nexthop_exceptions'David S. Miller
These patches implement the final mechanism necessary to really allow us to go without the route cache in ipv4. We need a place to have long-term storage of PMTU/redirect information which is independent of the routes themselves, yet does not get us back into a situation where we have to write to metrics or anything like that. For this we use an "next-hop exception" table in the FIB nexthops. The one thing I desperately want to avoid is having to create clone routes in the FIB trie for this purpose, because that is very expensive. However, I'm willing to entertain such an idea later if this current scheme proves to have downsides that the FIB trie variant would not have. In order to accomodate this any such scheme, we need to be able to produce a full flow key at PMTU/redirect time. That required an adjustment of the interface call-sites used to propagate these events. For a PMTU/redirect with a fully specified socket, we pass that socket and use it to produce the flow key. Otherwise we use a passed in SKB to formulate the key. There are two cases that need to be distinguished, ICMP message processing (in which case the IP header is at skb->data) and output packet processing (mostly tunnels, and in all such cases the IP header is at ip_hdr(skb)). We also have to make the code able to handle the case where the dst itself passed into the dst_ops->{update_pmtu,redirect} method is invalidated. This matters for calls from sockets that have cached that route. We provide a inet{,6} helper function for this purpose, and edit SCTP specially since it caches routes at the transport rather than socket level. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-17ipv4: Add FIB nexthop exceptions.David S. Miller
In a regime where we have subnetted route entries, we need a way to store persistent storage about destination specific learned values such as redirects and PMTU values. This is implemented here via nexthop exceptions. The initial implementation is a 2048 entry hash table with relaiming starting at chain length 5. A more sophisticated scheme can be devised if that proves necessary. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-17tcp: implement RFC 5961 4.2Eric Dumazet
Implement the RFC 5691 mitigation against Blind Reset attack using SYN bit. Section 4.2 of RFC 5961 advises to send a Challenge ACK and drop incoming packet, instead of resetting the session. Add a new SNMP counter to count number of challenge acks sent in response to SYN packets. (netstat -s | grep TCPSYNChallenge) Remove obsolete TCPAbortOnSyn, since we no longer abort a TCP session because of a SYN flag. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Kiran Kumar Kella <kkiran@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-17net: Pass optional SKB and SK arguments to dst_ops->{update_pmtu,redirect}()David S. Miller
This will be used so that we can compose a full flow key. Even though we have a route in this context, we need more. In the future the routes will be without destination address, source address, etc. keying. One ipv4 route will cover entire subnets, etc. In this environment we have to have a way to possess persistent storage for redirects and PMTU information. This persistent storage will exist in the FIB tables, and that's why we'll need to be able to rebuild a full lookup flow key here. Using that flow key will do a fib_lookup() and create/update the persistent entry. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-17tcp: implement RFC 5961 3.2Eric Dumazet
Implement the RFC 5691 mitigation against Blind Reset attack using RST bit. Idea is to validate incoming RST sequence, to match RCV.NXT value, instead of previouly accepted window : (RCV.NXT <= SEG.SEQ < RCV.NXT+RCV.WND) If sequence is in window but not an exact match, send a "challenge ACK", so that the other part can resend an RST with the appropriate sequence. Add a new sysctl, tcp_challenge_ack_limit, to limit number of challenge ACK sent per second. Add a new SNMP counter to count number of challenge acks sent. (netstat -s | grep TCPChallengeACK) Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Kiran Kumar Kella <kkiran@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-16net: make sock diag per-namespaceAndrey Vagin
Before this patch sock_diag works for init_net only and dumps information about sockets from all namespaces. This patch expands sock_diag for all name-spaces. It creates a netlink kernel socket for each netns and filters data during dumping. v2: filter accoding with netns in all places remove an unused variable. Cc: "David S. Miller" <davem@davemloft.net> Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Cc: James Morris <jmorris@namei.org> Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org> Cc: Patrick McHardy <kaber@trash.net> Cc: Pavel Emelyanov <xemul@parallels.com> CC: Eric Dumazet <eric.dumazet@gmail.com> Cc: linux-kernel@vger.kernel.org Cc: netdev@vger.kernel.org Signed-off-by: Andrew Vagin <avagin@openvz.org> Acked-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-16tcp: add OFO snmp countersEric Dumazet
Add three SNMP TCP counters, to better track TCP behavior at global stage (netstat -s), when packets are received Out Of Order (OFO) TCPOFOQueue : Number of packets queued in OFO queue TCPOFODrop : Number of packets meant to be queued in OFO but dropped because socket rcvbuf limit hit. TCPOFOMerge : Number of packets in OFO that were merged with other packets. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-16ipv4: Add helper inet_csk_update_pmtu().David S. Miller
This abstracts away the call to dst_ops->update_pmtu() so that we can transparently handle the fact that, in the future, the dst itself can be invalidated by the PMTU update (when we have non-host routes cached in sockets). So we try to rebuild the socket cached route after the method invocation if necessary. This isn't used by SCTP because it needs to cache dsts per-transport, and thus will need it's own local version of this helper. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-13ipv4: Don't store a rule pointer in fib_result.David S. Miller
We only use it to fetch the rule's tclassid, so just store the tclassid there instead. This also decreases the size of fib_result by a full 8 bytes on 64-bit. On 32-bits it's a wash. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-13tcp: add LAST_ACK as a valid state for TSQEric Dumazet
Socket state LAST_ACK should allow TSQ to send additional frames, or else we rely on incoming ACKS or timers to send them. Reported-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Matt Mathis <mattmathis@google.com> Cc: Mahesh Bandewar <maheshb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-12ipv4: Remove tb_peers from fib_table.David S. Miller
No longer used. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-12ipv4: Put proper checks into icmp_socket_deliver().David S. Miller
All handler->err() routines expect that we've done a pskb_may_pull() test to make sure that IP header length + 8 bytes can be safely pulled. Reported-by: Hiroaki SHIMODA <shimoda.hiroaki@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-12ipv4: Fix warnings in ip_do_redirect() for some configurations.David S. Miller
Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-12net: Remove checks for dst_ops->redirect being NULL.David S. Miller
No longer necessary. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-12net: Add dummy dst_ops->redirect method where needed.David S. Miller
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-11ipv4: Kill ip_rt_redirect().David S. Miller
No longer needed, as the protocol handlers now all properly propagate the redirect back into the routing code. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-11ipv4: Add redirect support to all protocol icmp error handlers.David S. Miller
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-11ipv4: Add ipv4_redirect() and ipv4_sk_redirect() helper functions.David S. Miller
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-11ipv4: Generalize ip_do_redirect() and hook into new dst_ops->redirect.David S. Miller
All of the redirect acceptance policy is now contained within. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-11ipv4: Rearrange arguments to ip_rt_redirect()David S. Miller
Pass in the SKB rather than just the IP addresses, so that policy and other aspects can reside in ip_rt_redirect() rather then icmp_redirect(). Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-11ipv4: Pull redirect instantiation out into a helper function.David S. Miller
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-11ipv4: Deliver ICMP redirects to sockets too.David S. Miller
And thus, we can remove the ping_err() hack. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-11ipv4: Pull icmp socket delivery out into a helper function.David S. Miller
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-11tcp: TCP Small QueuesEric Dumazet
This introduce TSQ (TCP Small Queues) TSQ goal is to reduce number of TCP packets in xmit queues (qdisc & device queues), to reduce RTT and cwnd bias, part of the bufferbloat problem. sk->sk_wmem_alloc not allowed to grow above a given limit, allowing no more than ~128KB [1] per tcp socket in qdisc/dev layers at a given time. TSO packets are sized/capped to half the limit, so that we have two TSO packets in flight, allowing better bandwidth use. As a side effect, setting the limit to 40000 automatically reduces the standard gso max limit (65536) to 40000/2 : It can help to reduce latencies of high prio packets, having smaller TSO packets. This means we divert sock_wfree() to a tcp_wfree() handler, to queue/send following frames when skb_orphan() [2] is called for the already queued skbs. Results on my dev machines (tg3/ixgbe nics) are really impressive, using standard pfifo_fast, and with or without TSO/GSO. Without reduction of nominal bandwidth, we have reduction of buffering per bulk sender : < 1ms on Gbit (instead of 50ms with TSO) < 8ms on 100Mbit (instead of 132 ms) I no longer have 4 MBytes backlogged in qdisc by a single netperf session, and both side socket autotuning no longer use 4 Mbytes. As skb destructor cannot restart xmit itself ( as qdisc lock might be taken at this point ), we delegate the work to a tasklet. We use one tasklest per cpu for performance reasons. If tasklet finds a socket owned by the user, it sets TSQ_OWNED flag. This flag is tested in a new protocol method called from release_sock(), to eventually send new segments. [1] New /proc/sys/net/ipv4/tcp_limit_output_bytes tunable [2] skb_orphan() is usually called at TX completion time, but some drivers call it in their start_xmit() handler. These drivers should at least use BQL, or else a single TCP session can still fill the whole NIC TX ring, since TSQ will have no effect. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Dave Taht <dave.taht@bufferbloat.net> Cc: Tom Herbert <therbert@google.com> Cc: Matt Mathis <mattmathis@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Nandita Dukkipati <nanditad@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-11tcp: Fix out of bounds access to tcpm_valsAlexander Duyck
The recent patch "tcp: Maintain dynamic metrics in local cache." introduced an out of bounds access due to what appears to be a typo. I believe this change should resolve the issue by replacing the access to RTAX_CWND with TCP_METRIC_CWND. Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>