summaryrefslogtreecommitdiff
path: root/net/ipv4
AgeCommit message (Collapse)AuthorFilesLines
2014-09-29Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-nextDavid S. Miller1-22/+24
Pablo Neira Ayuso says: ==================== pull request: netfilter/ipvs updates for net-next The following patchset contains Netfilter/IPVS updates for net-next, most relevantly they are: 1) Four patches to make the new nf_tables masquerading support independent of the x_tables infrastructure. This also resolves a compilation breakage if the masquerade target is disabled but the nf_tables masq expression is enabled. 2) ipset updates via Jozsef Kadlecsik. This includes the addition of the skbinfo extension that allows you to store packet metainformation in the elements. This can be used to fetch and restore this to the packets through the iptables SET target, patches from Anton Danilov. 3) Add the hash:mac set type to ipset, from Jozsef Kadlecsick. 4) Add simple weighted fail-over scheduler via Simon Horman. This provides a fail-over IPVS scheduler (unlike existing load balancing schedulers). Connections are directed to the appropriate server based solely on highest weight value and server availability, patch from Kenny Mathis. 5) Support IPv6 real servers in IPv4 virtual-services and vice versa. Simon Horman informs that the motivation for this is to allow more flexibility in the choice of IP version offered by both virtual-servers and real-servers as they no longer need to match: An IPv4 connection from an end-user may be forwarded to a real-server using IPv6 and vice versa. No ip_vs_sync support yet though. Patches from Alex Gartrell and Julian Anastasov. 6) Add global generation ID to the nf_tables ruleset. When dumping from several different object lists, we need a way to identify that an update has ocurred so userspace knows that it needs to refresh its lists. This also includes a new command to obtain the 32-bits generation ID. The less significant 16-bits of this ID is also exposed through res_id field in the nfnetlink header to quickly detect the interference and retry when there is no risk of ID wraparound. 7) Move br_netfilter out of the bridge core. The br_netfilter code is built in the bridge core by default. This causes problems of different kind to people that don't want this: Jesper reported performance drop due to the inconditional hook registration and I remember to have read complains on netdev from people regarding the unexpected behaviour of our bridging stack when br_netfilter is enabled (fragmentation handling, layer 3 and upper inspection). People that still need this should easily undo the damage by modprobing the new br_netfilter module. 8) Dump the set policy nf_tables that allows set parameterization. So userspace can keep user-defined preferences when saving the ruleset. From Arturo Borrero. 9) Use __seq_open_private() helper function to reduce boiler plate code in x_tables, From Rob Jones. 10) Safer default behaviour in case that you forget to load the protocol tracker. Daniel Borkmann and Florian Westphal detected that if your ruleset is stateful, you allow traffic to at least one single SCTP port and the SCTP protocol tracker is not loaded, then any SCTP traffic may be pass through unfiltered. After this patch, the connection tracking classifies SCTP/DCCP/UDPlite/GRE packets as invalid if your kernel has been compiled with support for these modules. ==================== Trivially resolved conflict in include/linux/skbuff.h, Eric moved some netfilter skbuff members around, and the netfilter tree adjusted the ifdef guards for the bridging info pointer. Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-29tcp: change TCP_ECN prefixes to lower caseFlorian Westphal3-31/+34
Suggested by Stephen. Also drop inline keyword and let compiler decide. gcc 4.7.3 decides to no longer inline tcp_ecn_check_ce, so split it up. The actual evaluation is not inlined anymore while the ECN_OK test is. Suggested-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-29tcp: move TCP_ECN_create_request out of headerFlorian Westphal1-1/+35
After Octavian Purdilas tcp ipv4/ipv6 unification work this helper only has a single callsite. While at it, convert name to lowercase, suggested by Stephen. Suggested-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-29tcp: remove unnecessary assignment.Li RongQing1-1/+1
This variable i is overwritten to 0 by following code Signed-off-by: Li RongQing <roy.qing.li@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-29net: tcp: add DCTCP congestion control algorithmDaniel Borkmann4-1/+371
This work adds the DataCenter TCP (DCTCP) congestion control algorithm [1], which has been first published at SIGCOMM 2010 [2], resp. follow-up analysis at SIGMETRICS 2011 [3] (and also, more recently as an informational IETF draft available at [4]). DCTCP is an enhancement to the TCP congestion control algorithm for data center networks. Typical data center workloads are i.e. i) partition/aggregate (queries; bursty, delay sensitive), ii) short messages e.g. 50KB-1MB (for coordination and control state; delay sensitive), and iii) large flows e.g. 1MB-100MB (data update; throughput sensitive). DCTCP has therefore been designed for such environments to provide/achieve the following three requirements: * High burst tolerance (incast due to partition/aggregate) * Low latency (short flows, queries) * High throughput (continuous data updates, large file transfers) with commodity, shallow buffered switches The basic idea of its design consists of two fundamentals: i) on the switch side, packets are being marked when its internal queue length > threshold K (K is chosen so that a large enough headroom for marked traffic is still available in the switch queue); ii) the sender/host side maintains a moving average of the fraction of marked packets, so each RTT, F is being updated as follows: F := X / Y, where X is # of marked ACKs, Y is total # of ACKs alpha := (1 - g) * alpha + g * F, where g is a smoothing constant The resulting alpha (iow: probability that switch queue is congested) is then being used in order to adaptively decrease the congestion window W: W := (1 - (alpha / 2)) * W The means for receiving marked packets resp. marking them on switch side in DCTCP is the use of ECN. RFC3168 describes a mechanism for using Explicit Congestion Notification from the switch for early detection of congestion, rather than waiting for segment loss to occur. However, this method only detects the presence of congestion, not the *extent*. In the presence of mild congestion, it reduces the TCP congestion window too aggressively and unnecessarily affects the throughput of long flows [4]. DCTCP, as mentioned, enhances Explicit Congestion Notification (ECN) processing to estimate the fraction of bytes that encounter congestion, rather than simply detecting that some congestion has occurred. DCTCP then scales the TCP congestion window based on this estimate [4], thus it can derive multibit feedback from the information present in the single-bit sequence of marks in its control law. And thus act in *proportion* to the extent of congestion, not its *presence*. Switches therefore set the Congestion Experienced (CE) codepoint in packets when internal queue lengths exceed threshold K. Resulting, DCTCP delivers the same or better throughput than normal TCP, while using 90% less buffer space. It was found in [2] that DCTCP enables the applications to handle 10x the current background traffic, without impacting foreground traffic. Moreover, a 10x increase in foreground traffic did not cause any timeouts, and thus largely eliminates TCP incast collapse problems. The algorithm itself has already seen deployments in large production data centers since then. We did a long-term stress-test and analysis in a data center, short summary of our TCP incast tests with iperf compared to cubic: This test measured DCTCP throughput and latency and compared it with CUBIC throughput and latency for an incast scenario. In this test, 19 senders sent at maximum rate to a single receiver. The receiver simply ran iperf -s. The senders ran iperf -c <receiver> -t 30. All senders started simultaneously (using local clocks synchronized by ntp). This test was repeated multiple times. Below shows the results from a single test. Other tests are similar. (DCTCP results were extremely consistent, CUBIC results show some variance induced by the TCP timeouts that CUBIC encountered.) For this test, we report statistics on the number of TCP timeouts, flow throughput, and traffic latency. 1) Timeouts (total over all flows, and per flow summaries): CUBIC DCTCP Total 3227 25 Mean 169.842 1.316 Median 183 1 Max 207 5 Min 123 0 Stddev 28.991 1.600 Timeout data is taken by measuring the net change in netstat -s "other TCP timeouts" reported. As a result, the timeout measurements above are not restricted to the test traffic, and we believe that it is likely that all of the "DCTCP timeouts" are actually timeouts for non-test traffic. We report them nevertheless. CUBIC will also include some non-test timeouts, but they are drawfed by bona fide test traffic timeouts for CUBIC. Clearly DCTCP does an excellent job of preventing TCP timeouts. DCTCP reduces timeouts by at least two orders of magnitude and may well have eliminated them in this scenario. 2) Throughput (per flow in Mbps): CUBIC DCTCP Mean 521.684 521.895 Median 464 523 Max 776 527 Min 403 519 Stddev 105.891 2.601 Fairness 0.962 0.999 Throughput data was simply the average throughput for each flow reported by iperf. By avoiding TCP timeouts, DCTCP is able to achieve much better per-flow results. In CUBIC, many flows experience TCP timeouts which makes flow throughput unpredictable and unfair. DCTCP, on the other hand, provides very clean predictable throughput without incurring TCP timeouts. Thus, the standard deviation of CUBIC throughput is dramatically higher than the standard deviation of DCTCP throughput. Mean throughput is nearly identical because even though cubic flows suffer TCP timeouts, other flows will step in and fill the unused bandwidth. Note that this test is something of a best case scenario for incast under CUBIC: it allows other flows to fill in for flows experiencing a timeout. Under situations where the receiver is issuing requests and then waiting for all flows to complete, flows cannot fill in for timed out flows and throughput will drop dramatically. 3) Latency (in ms): CUBIC DCTCP Mean 4.0088 0.04219 Median 4.055 0.0395 Max 4.2 0.085 Min 3.32 0.028 Stddev 0.1666 0.01064 Latency for each protocol was computed by running "ping -i 0.2 <receiver>" from a single sender to the receiver during the incast test. For DCTCP, "ping -Q 0x6 -i 0.2 <receiver>" was used to ensure that traffic traversed the DCTCP queue and was not dropped when the queue size was greater than the marking threshold. The summary statistics above are over all ping metrics measured between the single sender, receiver pair. The latency results for this test show a dramatic difference between CUBIC and DCTCP. CUBIC intentionally overflows the switch buffer which incurs the maximum queue latency (more buffer memory will lead to high latency.) DCTCP, on the other hand, deliberately attempts to keep queue occupancy low. The result is a two orders of magnitude reduction of latency with DCTCP - even with a switch with relatively little RAM. Switches with larger amounts of RAM will incur increasing amounts of latency for CUBIC, but not for DCTCP. 4) Convergence and stability test: This test measured the time that DCTCP took to fairly redistribute bandwidth when a new flow commences. It also measured DCTCP's ability to remain stable at a fair bandwidth distribution. DCTCP is compared with CUBIC for this test. At the commencement of this test, a single flow is sending at maximum rate (near 10 Gbps) to a single receiver. One second after that first flow commences, a new flow from a distinct server begins sending to the same receiver as the first flow. After the second flow has sent data for 10 seconds, the second flow is terminated. The first flow sends for an additional second. Ideally, the bandwidth would be evenly shared as soon as the second flow starts, and recover as soon as it stops. The results of this test are shown below. Note that the flow bandwidth for the two flows was measured near the same time, but not simultaneously. DCTCP performs nearly perfectly within the measurement limitations of this test: bandwidth is quickly distributed fairly between the two flows, remains stable throughout the duration of the test, and recovers quickly. CUBIC, in contrast, is slow to divide the bandwidth fairly, and has trouble remaining stable. CUBIC DCTCP Seconds Flow 1 Flow 2 Seconds Flow 1 Flow 2 0 9.93 0 0 9.92 0 0.5 9.87 0 0.5 9.86 0 1 8.73 2.25 1 6.46 4.88 1.5 7.29 2.8 1.5 4.9 4.99 2 6.96 3.1 2 4.92 4.94 2.5 6.67 3.34 2.5 4.93 5 3 6.39 3.57 3 4.92 4.99 3.5 6.24 3.75 3.5 4.94 4.74 4 6 3.94 4 5.34 4.71 4.5 5.88 4.09 4.5 4.99 4.97 5 5.27 4.98 5 4.83 5.01 5.5 4.93 5.04 5.5 4.89 4.99 6 4.9 4.99 6 4.92 5.04 6.5 4.93 5.1 6.5 4.91 4.97 7 4.28 5.8 7 4.97 4.97 7.5 4.62 4.91 7.5 4.99 4.82 8 5.05 4.45 8 5.16 4.76 8.5 5.93 4.09 8.5 4.94 4.98 9 5.73 4.2 9 4.92 5.02 9.5 5.62 4.32 9.5 4.87 5.03 10 6.12 3.2 10 4.91 5.01 10.5 6.91 3.11 10.5 4.87 5.04 11 8.48 0 11 8.49 4.94 11.5 9.87 0 11.5 9.9 0 SYN/ACK ECT test: This test demonstrates the importance of ECT on SYN and SYN-ACK packets by measuring the connection probability in the presence of competing flows for a DCTCP connection attempt *without* ECT in the SYN packet. The test was repeated five times for each number of competing flows. Competing Flows 1 | 2 | 4 | 8 | 16 ------------------------------ Mean Connection Probability 1 | 0.67 | 0.45 | 0.28 | 0 Median Connection Probability 1 | 0.65 | 0.45 | 0.25 | 0 As the number of competing flows moves beyond 1, the connection probability drops rapidly. Enabling DCTCP with this patch requires the following steps: DCTCP must be running both on the sender and receiver side in your data center, i.e.: sysctl -w net.ipv4.tcp_congestion_control=dctcp Also, ECN functionality must be enabled on all switches in your data center for DCTCP to work. The default ECN marking threshold (K) heuristic on the switch for DCTCP is e.g., 20 packets (30KB) at 1Gbps, and 65 packets (~100KB) at 10Gbps (K > 1/7 * C * RTT, [4]). In above tests, for each switch port, traffic was segregated into two queues. For any packet with a DSCP of 0x01 - or equivalently a TOS of 0x04 - the packet was placed into the DCTCP queue. All other packets were placed into the default drop-tail queue. For the DCTCP queue, RED/ECN marking was enabled, here, with a marking threshold of 75 KB. More details however, we refer you to the paper [2] under section 3). There are no code changes required to applications running in user space. DCTCP has been implemented in full *isolation* of the rest of the TCP code as its own congestion control module, so that it can run without a need to expose code to the core of the TCP stack, and thus nothing changes for non-DCTCP users. Changes in the CA framework code are minimal, and DCTCP algorithm operates on mechanisms that are already available in most Silicon. The gain (dctcp_shift_g) is currently a fixed constant (1/16) from the paper, but we leave the option that it can be chosen carefully to a different value by the user. In case DCTCP is being used and ECN support on peer site is off, DCTCP falls back after 3WHS to operate in normal TCP Reno mode. ss {-4,-6} -t -i diag interface: ... dctcp wscale:7,7 rto:203 rtt:2.349/0.026 mss:1448 cwnd:2054 ssthresh:1102 ce_state 0 alpha 15 ab_ecn 0 ab_tot 735584 send 10129.2Mbps pacing_rate 20254.1Mbps unacked:1822 retrans:0/15 reordering:101 rcv_space:29200 ... dctcp-reno wscale:7,7 rto:201 rtt:0.711/1.327 ato:40 mss:1448 cwnd:10 ssthresh:1102 fallback_mode send 162.9Mbps pacing_rate 325.5Mbps rcv_rtt:1.5 rcv_space:29200 More information about DCTCP can be found in [1-4]. [1] http://simula.stanford.edu/~alizade/Site/DCTCP.html [2] http://simula.stanford.edu/~alizade/Site/DCTCP_files/dctcp-final.pdf [3] http://simula.stanford.edu/~alizade/Site/DCTCP_files/dctcp_analysis-full.pdf [4] http://tools.ietf.org/html/draft-bensley-tcpm-dctcp-00 Joint work with Florian Westphal and Glenn Judd. Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Glenn Judd <glenn.judd@morganstanley.com> Acked-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-29net: tcp: more detailed ACK events and events for CE marked packetsFlorian Westphal2-4/+22
DataCenter TCP (DCTCP) determines cwnd growth based on ECN information and ACK properties, e.g. ACK that updates window is treated differently than DUPACK. Also DCTCP needs information whether ACK was delayed ACK. Furthermore, DCTCP also implements a CE state machine that keeps track of CE markings of incoming packets. Therefore, extend the congestion control framework to provide these event types, so that DCTCP can be properly implemented as a normal congestion algorithm module outside of the core stack. Joint work with Daniel Borkmann and Glenn Judd. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Glenn Judd <glenn.judd@morganstanley.com> Acked-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-29net: tcp: split ack slow/fast events from cwnd_eventFlorian Westphal2-14/+26
The congestion control ops "cwnd_event" currently supports CA_EVENT_FAST_ACK and CA_EVENT_SLOW_ACK events (among others). Both FAST and SLOW_ACK are only used by Westwood congestion control algorithm. This removes both flags from cwnd_event and adds a new in_ack_event callback for this. The goal is to be able to provide more detailed information about ACKs, such as whether ECE flag was set, or whether the ACK resulted in a window update. It is required for DataCenter TCP (DCTCP) congestion control algorithm as it makes a different choice depending on ECE being set or not. Joint work with Daniel Borkmann and Glenn Judd. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Glenn Judd <glenn.judd@morganstanley.com> Acked-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-29net: tcp: add flag for ca to indicate that ECN is requiredDaniel Borkmann2-8/+19
This patch adds a flag to TCP congestion algorithms that allows for requesting to mark IPv4/IPv6 sockets with transport as ECN capable, that is, ECT(0), when required by a congestion algorithm. It is currently used and needed in DataCenter TCP (DCTCP), as it requires both peers to assert ECT on all IP packets sent - it uses ECN feedback (i.e. CE, Congestion Encountered information) from switches inside the data center to derive feedback to the end hosts. Therefore, simply add a new flag to icsk_ca_ops. Note that DCTCP's algorithm/behaviour slightly diverges from RFC3168, therefore this is only (!) enabled iff the assigned congestion control ops module has requested this. By that, we can tightly couple this logic really only to the provided congestion control ops. Joint work with Florian Westphal and Glenn Judd. Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Glenn Judd <glenn.judd@morganstanley.com> Acked-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-29net: tcp: assign tcp cong_ops when tcp sk is createdFlorian Westphal3-31/+26
Split assignment and initialization from one into two functions. This is required by followup patches that add Datacenter TCP (DCTCP) congestion control algorithm - we need to be able to determine if the connection is moderated by DCTCP before the 3WHS has finished. As we walk the available congestion control list during the assignment, we are always guaranteed to have Reno present as it's fixed compiled-in. Therefore, since we're doing the early assignment, we don't have a real use for the Reno alias tcp_init_congestion_ops anymore and can thus remove it. Actual usage of the congestion control operations are being made after the 3WHS has finished, in some cases however we can access get_info() via diag if implemented, therefore we need to zero out the private area for those modules. Joint work with Daniel Borkmann and Glenn Judd. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Glenn Judd <glenn.judd@morganstanley.com> Acked-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-29arp: Do not perturb drop profiles with ignored ARP packetsRick Jones1-1/+5
We do not wish to disturb dropwatch or perf drop profiles with an ARP we will ignore. Signed-off-by: Rick Jones <rick.jones2@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-29Merge branch 'master' of ↵David S. Miller1-2/+0
git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next Steffen Klassert says: ==================== pull request (net-next): ipsec-next 2014-09-25 1) Remove useless hash_resize_mutex in xfrm_hash_resize(). This mutex is used only there, but xfrm_hash_resize() can't be called concurrently at all. From Ying Xue. 2) Extend policy hashing to prefixed policies based on prefix lenght thresholds. From Christophe Gouault. 3) Make the policy hash table thresholds configurable via netlink. From Christophe Gouault. 4) Remove the maximum authentication length for AH. This was needed to limit stack usage. We switched already to allocate space, so no need to keep the limit. From Herbert Xu. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-29tcp: use tcp_flags in tcp_data_queue()Peter Pan(潘卫平)1-3/+2
This patch is a cleanup which follows the idea in commit e11ecddf5128 (tcp: use TCP_SKB_CB(skb)->tcp_flags in input path), and it may reduce register pressure since skb->cb[] access is fast, bacause skb is probably in a register. v2: remove variable th v3: reword the changelog Signed-off-by: Weiping Pan <panweiping3@gmail.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-29tcp: change tcp_skb_pcount() locationEric Dumazet3-9/+12
Our goal is to access no more than one cache line access per skb in a write or receive queue when doing the various walks. After recent TCP_SKB_CB() reorganizations, it is almost done. Last part is tcp_skb_pcount() which currently uses skb_shinfo(skb)->gso_segs, which is a terrible choice, because it needs 3 cache lines in current kernel (skb->head, skb->end, and shinfo->gso_segs are all in 3 different cache lines, far from skb->cb) This very simple patch reuses space currently taken by tcp_tw_isn only in input path, as tcp_skb_pcount is only needed for skb stored in write queue. This considerably speeds up tcp_ack(), granted we avoid shinfo->tx_flags to get SKBTX_ACK_TSTAMP, which seems possible. This also speeds up all sack processing in general. This speeds up tcp_sendmsg() because it no longer has to access/dirty shinfo. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-29tcp: better TCP_SKB_CB layout to reduce cache line missesEric Dumazet2-7/+17
TCP maintains lists of skb in write queue, and in receive queues (in order and out of order queues) Scanning these lists both in input and output path usually requires access to skb->next, TCP_SKB_CB(skb)->seq, and TCP_SKB_CB(skb)->end_seq These fields are currently in two different cache lines, meaning we waste lot of memory bandwidth when these queues are big and flows have either packet drops or packet reorders. We can move TCP_SKB_CB(skb)->header at the end of TCP_SKB_CB, because this header is not used in fast path. This allows TCP to search much faster in the skb lists. Even with regular flows, we save one cache line miss in fast path. Thanks to Christoph Paasch for noticing we need to cleanup skb->cb[] (IPCB/IP6CB) before entering IP stack in tx path, and that I forgot IPCB use in tcp_v4_hnd_req() and tcp_v4_save_options(). Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-29ipv4: rename ip_options_echo to __ip_options_echo()Eric Dumazet3-11/+13
ip_options_echo() assumes struct ip_options is provided in &IPCB(skb)->opt Lets break this assumption, but provide a helper to not change all call points. ip_send_unicast_reply() gets a new struct ip_options pointer. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-26net: introduce __skb_header_release()Eric Dumazet2-7/+7
While profiling TCP stack, I noticed one useless atomic operation in tcp_sendmsg(), caused by skb_header_release(). It turns out all current skb_header_release() users have a fresh skb, that no other user can see, so we can avoid one atomic operation. Introduce __skb_header_release() to clearly document this. This gave me a 1.5 % improvement on TCP_RR workload. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-26net: Remove gso_send_check as an offload callbackTom Herbert4-56/+3
The send_check logic was only interesting in cases of TCP offload and UDP UFO where the checksum needed to be initialized to the pseudo header checksum. Now we've moved that logic into the related gso_segment functions so gso_send_check is no longer needed. Signed-off-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-26udp: move logic out of udp[46]_ufo_send_checkTom Herbert1-22/+15
In udp[46]_ufo_send_check the UDP checksum initialized to the pseudo header checksum. We can move this logic into udp[46]_ufo_fragment. After this change udp[64]_ufo_send_check is a no-op. Signed-off-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-26tcp: move logic out of tcp_v[64]_gso_send_checkTom Herbert1-16/+23
In tcp_v[46]_gso_send_check the TCP checksum is initialized to the pseudo header checksum using __tcp_v[46]_send_check. We can move this logic into new tcp[46]_gso_segment functions to be done when ip_summed != CHECKSUM_PARTIAL (ip_summed == CHECKSUM_PARTIAL should be the common case, possibly always true when taking GSO path). After this change tcp_v[46]_gso_send_check is no-op. Signed-off-by: Tom Herbert <therbert@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-23tcp: add coalescing attempt in tcp_ofo_queue()Eric Dumazet1-42/+47
In order to make TCP more resilient in presence of reorders, we need to allow coalescing to happen when skbs from out of order queue are transferred into receive queue. LRO/GRO can be completely canceled in some pathological cases, like per packet load balancing on aggregated links. I had to move tcp_try_coalesce() up in the file above tcp_ofo_queue() Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-23icmp: add a global rate limitationEric Dumazet2-4/+76
Current ICMP rate limiting uses inetpeer cache, which is an RBL tree protected by a lock, meaning that hosts can be stuck hard if all cpus want to check ICMP limits. When say a DNS or NTP server process is restarted, inetpeer tree grows quick and machine comes to its knees. iptables can not help because the bottleneck happens before ICMP messages are even cooked and sent. This patch adds a new global limitation, using a token bucket filter, controlled by two new sysctl : icmp_msgs_per_sec - INTEGER Limit maximal number of ICMP packets sent per second from this host. Only messages whose type matches icmp_ratemask are controlled by this limit. Default: 1000 icmp_msgs_burst - INTEGER icmp_msgs_per_sec controls number of ICMP packets sent per second, while icmp_msgs_burst controls the burst size of these packets. Default: 50 Note that if we really want to send millions of ICMP messages per second, we might extend idea and infra added in commit 04ca6973f7c1a ("ip: make IP identifiers less predictable") : add a token bucket in the ip_idents hash and no longer rely on inetpeer. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2-6/+6
Conflicts: arch/mips/net/bpf_jit.c drivers/net/can/flexcan.c Both the flexcan and MIPS bpf_jit conflicts were cases of simple overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-23ipv4: do not use this_cpu_ptr() in preemptible contextEric Dumazet1-3/+3
this_cpu_ptr() in preemptible context is generally bad Sep 22 05:05:55 br kernel: [ 94.608310] BUG: using smp_processor_id() in preemptible [00000000] code: ip/2261 Sep 22 05:05:55 br kernel: [ 94.608316] caller is tunnel_dst_set.isra.28+0x20/0x60 [ip_tunnel] Sep 22 05:05:55 br kernel: [ 94.608319] CPU: 3 PID: 2261 Comm: ip Not tainted 3.17.0-rc5 #82 We can simply use raw_cpu_ptr(), as preemption is safe in these contexts. Should fix https://bugzilla.kernel.org/show_bug.cgi?id=84991 Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Joe <joe9mail@gmail.com> Fixes: 9a4aa9af447f ("ipv4: Use percpu Cache route in IP tunnels") Acked-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-23tcp: avoid possible arithmetic overflowsEric Dumazet4-14/+14
icsk_rto is a 32bit field, and icsk_backoff can reach 15 by default, or more if some sysctl (eg tcp_retries2) are changed. Better use 64bit to perform icsk_rto << icsk_backoff operations As Joe Perches suggested, add a helper for this. Yuchung spotted the tcp_v4_err() case. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-20gre: Setup and TX path for gre/UDP foo-over-udp encapsulationTom Herbert1-5/+85
Added netlink attrs to configure FOU encapsulation for GRE, netlink handling of these flags, and properly adjust MTU for encapsulation. ip_tunnel_encap is called from ip_tunnel_xmit to actually perform FOU encapsulation. Signed-off-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-20ipip: Setup and TX path for ipip/UDP foo-over-udp encapsulationTom Herbert1-1/+77
Add netlink handling for IP tunnel encapsulation parameters and and adjustment of MTU for encapsulation. ip_tunnel_encap is called from ip_tunnel_xmit to actually perform FOU encapsulation. Signed-off-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-20net: Changes to ip_tunnel to support foo-over-udp encapsulationTom Herbert1-1/+90
This patch changes IP tunnel to support (secondary) encapsulation, Foo-over-UDP. Changes include: 1) Adding tun_hlen as the tunnel header length, encap_hlen as the encapsulation header length, and hlen becomes the grand total of these. 2) Added common netlink define to support FOU encapsulation. 3) Routines to perform FOU encapsulation. Signed-off-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-20fou: Add GRO supportTom Herbert2-1/+93
Implement fou_gro_receive and fou_gro_complete, and populate these in the correponsing udp_offloads for the socket. Added ipproto to udp_offloads and pass this from UDP to the fou GRO routine in proto field of napi_gro_cb structure. Signed-off-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-20fou: Support for foo-over-udp RX pathTom Herbert3-0/+290
This patch provides a receive path for foo-over-udp. This allows direct encapsulation of IP protocols over UDP. The bound destination port is used to map to an IP protocol, and the XFRM framework (udp_encap_rcv) is used to receive encapsulated packets. Upon reception, the encapsulation header is logically removed (pointer to transport header is advanced) and the packet is reinjected into the receive path with the IP protocol indicated by the mapping. Netlink is used to configure FOU ports. The configuration information includes the port number to bind to and the IP protocol corresponding to that port. This should support GRE/UDP (http://tools.ietf.org/html/draft-yong-tsvwg-gre-in-udp-encap-02), as will as the other IP tunneling protocols (IPIP, SIT). Signed-off-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-20net: Export inet_offloads and inet6_offloadsTom Herbert1-0/+1
Want to be able to use these in foo-over-udp offloads, etc. Signed-off-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-20tcp: do not fake tcp headers in tcp_send_rcvq()Eric Dumazet1-9/+4
Now we no longer rely on having tcp headers for skbs in receive queue, tcp repair do not need to build fake ones. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-19udp-tunnel: Add a few more UDP tunnel APIsAndy Zhou1-1/+52
Added a few more UDP tunnel APIs that can be shared by UDP based tunnel protocol implementation. The main ones are highlighted below. setup_udp_tunnel_sock() configures UDP listener socket for receiving UDP encapsulated packets. udp_tunnel_xmit_skb() and upd_tunnel6_xmit_skb() transmit skb using UDP encapsulation. udp_tunnel_sock_release() closes the UDP tunnel listener socket. Signed-off-by: Andy Zhou <azhou@nicira.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-19udp_tunnel: Seperate ipv6 functions into its own file.Andy Zhou1-64/+21
Add ip6_udp_tunnel.c for ipv6 UDP tunnel functions to avoid ifdefs in udp_tunnel.c Signed-off-by: Andy Zhou <azhou@nicira.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-18ipsec: Remove obsolete MAX_AH_AUTH_LENHerbert Xu1-2/+0
While tracking down the MAX_AH_AUTH_LEN crash in an old kernel I thought that this limit was rather arbitrary and we should just get rid of it. In fact it seems that we've already done all the work needed to remove it apart from actually removing it. This limit was there in order to limit stack usage. Since we've already switched over to allocating scratch space using kmalloc, there is no longer any need to limit the authentication length. This patch kills all references to it, including the BUG_ONs that led me here. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2014-09-16xfrm: Generate blackhole routes only from route lookup functionsSteffen Klassert1-3/+3
Currently we genarate a blackhole route route whenever we have matching policies but can not resolve the states. Here we assume that dst_output() is called to kill the balckholed packets. Unfortunately this assumption is not true in all cases, so it is possible that these packets leave the system unwanted. We fix this by generating blackhole routes only from the route lookup functions, here we can guarantee a call to dst_output() afterwards. Fixes: 2774c131b1d ("xfrm: Handle blackhole route creation via afinfo.") Reported-by: Konstantinos Kolelis <k.kolelis@sirrix.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2014-09-15tcp: do not copy headers in tcp_collapse()Eric Dumazet1-15/+2
tcp_collapse() wants to shrink skb so that the overhead is minimal. Now we store tcp flags into TCP_SKB_CB(skb)->tcp_flags, we no longer need to keep around full headers. Whole available space is dedicated to the payload. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-15tcp: allow segment with FIN in tcp_try_coalesce()Eric Dumazet1-3/+1
We can allow a segment with FIN to be aggregated, if we take care to add tcp flags, and if skb_try_coalesce() takes care of zero sized skbs. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-15tcp: use TCP_SKB_CB(skb)->tcp_flags in input pathEric Dumazet3-13/+16
Input path of TCP do not currently uses TCP_SKB_CB(skb)->tcp_flags, which is only used in output path. tcp_recvmsg(), looks at tcp_hdr(skb)->syn for every skb found in receive queue, and its unfortunate because this bit is located in a cache line right before the payload. We can simplify TCP by copying tcp flags into TCP_SKB_CB(skb)->tcp_flags. This patch does so, and avoids the cache line miss in tcp_recvmsg() Following patches will - allow a segment with FIN being coalesced in tcp_try_coalesce() - simplify tcp_collapse() by not copying the headers. Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-13udp: Fix inverted NAPI_GRO_CB(skb)->flush testScott Wood1-1/+1
Commit 2abb7cdc0d ("udp: Add support for doing checksum unnecessary conversion") caused napi_gro_cb structs with the "flush" field zero to take the "udp_gro_receive" path rather than the "set flush to 1" path that they would previously take. As a result I saw booting from an NFS root hang shortly after starting userspace, with "server not responding" messages. This change to the handling of "flush == 0" packets appears to be incidental to the goal of adding new code in the case where skb_gro_checksum_validate_zero_check() returns zero. Based on that and the fact that it breaks things, I'm assuming that it is unintentional. Fixes: 2abb7cdc0d ("udp: Add support for doing checksum unnecessary conversion") Cc: Tom Herbert <therbert@google.com> Signed-off-by: Scott Wood <scottwood@freescale.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-12netfilter: masquerading needs to be independent of x_tables in KconfigPablo Neira Ayuso1-12/+15
Users are starting to test nf_tables with no x_tables support. Therefore, masquerading needs to be indenpendent of it from Kconfig. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-09-12netfilter: NFT_CHAIN_NAT_IPV* is independent of NFT_NATPablo Neira Ayuso1-10/+9
Now that we have masquerading support in nf_tables, the NAT chain can be use with it, not only for SNAT/DNAT. So make this chain type independent of it. While at it, move it inside the scope of 'if NF_NAT_IPV*' to simplify dependencies. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-09-10Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-nextDavid S. Miller8-418/+536
Pablo Neira Ayuso says: ==================== nf-next pull request The following patchset contains Netfilter/IPVS updates for your net-next tree. Regarding nf_tables, most updates focus on consolidating the NAT infrastructure and adding support for masquerading. More specifically, they are: 1) use __u8 instead of u_int8_t in arptables header, from Mike Frysinger. 2) Add support to match by skb->pkttype to the meta expression, from Ana Rey. 3) Add support to match by cpu to the meta expression, also from Ana Rey. 4) A smatch warning about IPSET_ATTR_MARKMASK validation, patch from Vytas Dauksa. 5) Fix netnet and netportnet hash types the range support for IPv4, from Sergey Popovich. 6) Fix missing-field-initializer warnings resolved, from Mark Rustad. 7) Dan Carperter reported possible integer overflows in ipset, from Jozsef Kadlecsick. 8) Filter out accounting objects in nfacct by type, so you can selectively reset quotas, from Alexey Perevalov. 9) Move specific NAT IPv4 functions to the core so x_tables and nf_tables can share the same NAT IPv4 engine. 10) Use the new NAT IPv4 functions from nft_chain_nat_ipv4. 11) Move specific NAT IPv6 functions to the core so x_tables and nf_tables can share the same NAT IPv4 engine. 12) Use the new NAT IPv6 functions from nft_chain_nat_ipv6. 13) Refactor code to add nft_delrule(), which can be reused in the enhancement of the NFT_MSG_DELTABLE to remove a table and its content, from Arturo Borrero. 14) Add a helper function to unregister chain hooks, from Arturo Borrero. 15) A cleanup to rename to nft_delrule_by_chain for consistency with the new nft_*() functions, also from Arturo. 16) Add support to match devgroup to the meta expression, from Ana Rey. 17) Reduce stack usage for IPVS socket option, from Julian Anastasov. 18) Remove unnecessary textsearch state initialization in xt_string, from Bojan Prtvar. 19) Add several helper functions to nf_tables, more work to prepare the enhancement of NFT_MSG_DELTABLE, again from Arturo Borrero. 20) Enhance NFT_MSG_DELTABLE to delete a table and its content, from Arturo Borrero. 21) Support NAT flags in the nat expression to indicate the flavour, eg. random fully, from Arturo. 22) Add missing audit code to ebtables when replacing tables, from Nicolas Dichtel. 23) Generalize the IPv4 masquerading code to allow its re-use from nf_tables, from Arturo. 24) Generalize the IPv6 masquerading code, also from Arturo. 25) Add the new masq expression to support IPv4/IPv6 masquerading from nf_tables, also from Arturo. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-10ipip: Add gro callbacks to ipip offloadTom Herbert1-0/+2
Add inet_gro_receive and inet_gro_complete to ipip_offload to support GRO. Signed-off-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-10ipv4: udp4_gro_complete() is staticEric Dumazet1-1/+1
net/ipv4/udp_offload.c:339:5: warning: symbol 'udp4_gro_complete' was not declared. Should it be static? Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Tom Herbert <therbert@google.com> Fixes: 57c67ff4bd92 ("udp: additional GRO support") Acked-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-10ipv4: rcu cleanup in ip_ra_control()Eric Dumazet1-2/+2
Remove one sparse warning : net/ipv4/ip_sockglue.c:328:22: warning: incorrect type in assignment (different address spaces) net/ipv4/ip_sockglue.c:328:22: expected struct ip_ra_chain [noderef] <asn:4>*next net/ipv4/ip_sockglue.c:328:22: got struct ip_ra_chain *[assigned] ra And replace one rcu_assign_ptr() by RCU_INIT_POINTER() where applicable. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-10tcp: remove dst refcount false sharing for prequeue modeEric Dumazet1-4/+16
Alexander Duyck reported high false sharing on dst refcount in tcp stack when prequeue is used. prequeue is the mechanism used when a thread is blocked in recvmsg()/read() on a TCP socket, using a blocking model rather than select()/poll()/epoll() non blocking one. We already try to use RCU in input path as much as possible, but we were forced to take a refcount on the dst when skb escaped RCU protected region. When/if the user thread runs on different cpu, dst_release() will then touch dst refcount again. Commit 093162553c33 (tcp: force a dst refcount when prequeue packet) was an example of a race fix. It turns out the only remaining usage of skb->dst for a packet stored in a TCP socket prequeue is IP early demux. We can add a logic to detect when IP early demux is probably going to use skb->dst. Because we do an optimistic check rather than duplicate existing logic, we need to guard inet_sk_rx_dst_set() and inet6_sk_rx_dst_set() from using a NULL dst. Many thanks to Alexander for providing a nice bug report, git bisection, and reproducer. Tested using Alexander script on a 40Gb NIC, 8 RX queues. Hosts have 24 cores, 48 hyper threads. echo 0 >/proc/sys/net/ipv4/tcp_autocorking for i in `seq 0 47` do for j in `seq 0 2` do netperf -H $DEST -t TCP_STREAM -l 1000 \ -c -C -T $i,$i -P 0 -- \ -m 64 -s 64K -D & done done Before patch : ~6Mpps and ~95% cpu usage on receiver After patch : ~9Mpps and ~35% cpu usage on receiver. Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Alexander Duyck <alexander.h.duyck@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-09net/ipv4: bind ip_nonlocal_bind to current netnsVincent Bernat3-13/+9
net.ipv4.ip_nonlocal_bind sysctl was global to all network namespaces. This patch allows to set a different value for each network namespace. Signed-off-by: Vincent Bernat <vincent@bernat.im> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-09netfilter: nf_tables: add new nft_masq expressionArturo Borrero3-0/+96
The nft_masq expression is intended to perform NAT in the masquerade flavour. We decided to have the masquerade functionality in a separated expression other than nft_nat. Signed-off-by: Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-09-09netfilter: nf_nat: generalize IPv4 masquerading support for nf_tablesArturo Borrero4-99/+170
Let's refactor the code so we can reach the masquerade functionality from outside the xt context (ie. nftables). The patch includes the addition of an atomic counter to the masquerade notifier: the stuff to be done by the notifier is the same for xt and nftables. Therefore, only one notification handler is needed. This factorization only involves IPv4; a similar patch follows to handle IPv6. Signed-off-by: Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2014-09-09inet: remove dead inetpeer sequence codeWillem de Bruijn1-21/+0
inetpeer sequence numbers are no longer incremented, so no need to check and flush the tree. The function that increments the sequence number was already dead code and removed in in "ipv4: remove unused function" (068a6e18). Remove the code that checks for a change, too. Verifying that v4_seq and v6_seq are never incremented and thus that flush_check compares bp->flush_seq to 0 is trivial. The second part of the change removes flush_check completely even though bp->flush_seq is exactly !0 once, at initialization. This change is correct because the time this branch is true is when bp->root == peer_avl_empty_rcu, in which the branch and inetpeer_invalidate_tree are a NOOP. Signed-off-by: Willem de Bruijn <willemb@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>