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* ipv4: Revert removal of rt_uses_gatewayDavid Ahern2019-09-201-1/+1
| | | | | | | | | | | | | | | | | | | | Julian noted that rt_uses_gateway has a more subtle use than 'is gateway set': https://lore.kernel.org/netdev/alpine.LFD.2.21.1909151104060.2546@ja.home.ssi.bg/ Revert that part of the commit referenced in the Fixes tag. Currently, there are no u8 holes in 'struct rtable'. There is a 4-byte hole in the second cacheline which contains the gateway declaration. So move rt_gw_family down to the gateway declarations since they are always used together, and then re-use that u8 for rt_uses_gateway. End result is that rtable size is unchanged. Fixes: 1550c171935d ("ipv4: Prepare rtable for IPv6 gateway") Reported-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: David Ahern <dsahern@gmail.com> Reviewed-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
* ipv4: Prepare rtable for IPv6 gatewayDavid Ahern2019-04-081-1/+1
| | | | | | | | | | | To allow the gateway to be either an IPv4 or IPv6 address, remove rt_uses_gateway from rtable and replace with rt_gw_family. If rt_gw_family is set it implies rt_uses_gateway. Rename rt_gateway to rt_gw4 to represent the IPv4 version. Signed-off-by: David Ahern <dsahern@gmail.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2018-12-201-0/+1
|\ | | | | | | | | | | | | | | | | | | Lots of conflicts, by happily all cases of overlapping changes, parallel adds, things of that nature. Thanks to Stephen Rothwell, Saeed Mahameed, and others for their guidance in these resolutions. Signed-off-by: David S. Miller <davem@davemloft.net>
| * net: clear skb->tstamp in forwarding pathsEric Dumazet2018-12-151-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Sergey reported that forwarding was no longer working if fq packet scheduler was used. This is caused by the recent switch to EDT model, since incoming packets might have been timestamped by __net_timestamp() __net_timestamp() uses ktime_get_real(), while fq expects packets using CLOCK_MONOTONIC base. The fix is to clear skb->tstamp in forwarding paths. Fixes: 80b14dee2bea ("net: Add a new socket option for a future transmit time.") Fixes: fb420d5d91c1 ("tcp/fq: move back to CLOCK_MONOTONIC") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Sergey Matyukevich <geomatsi@gmail.com> Tested-by: Sergey Matyukevich <geomatsi@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | net: Do not route unicast IP packets twiceIdo Schimmel2018-12-041-0/+7
|/ | | | | | | | | | | | | Packets marked with 'offload_l3_fwd_mark' were already forwarded by a capable device and should not be forwarded again by the kernel. Therefore, have the kernel consume them. The check is performed in ip{,6}_forward_finish() in order to allow the kernel to process such packets in ip{,6}_forward() and generate required exceptions. For example, ICMP redirects. Signed-off-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: ipv4: Control SKB reprioritization after forwardingPetr Machata2018-08-011-1/+2
| | | | | | | | | | | | | | | | | | | After IPv4 packets are forwarded, the priority of the corresponding SKB is updated according to the TOS field of IPv4 header. This overrides any prioritization done earlier by e.g. an skbedit action or ingress-qos-map defined at a vlan device. Such overriding may not always be desirable. Even if the packet ends up being routed, which implies this is an L3 network node, an administrator may wish to preserve whatever prioritization was done earlier on in the pipeline. Therefore introduce a sysctl that controls this behavior. Keep the default value at 1 to maintain backward-compatible behavior. Signed-off-by: Petr Machata <petrm@mellanox.com> Reviewed-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: rename skb_gso_validate_mtu -> skb_gso_validate_network_lenDaniel Axtens2018-03-041-1/+1
| | | | | | | | | | | | | | | If you take a GSO skb, and split it into packets, will the network length (L3 headers + L4 headers + payload) of those packets be small enough to fit within a given MTU? skb_gso_validate_mtu gives you the answer to that question. However, we recently added to add a way to validate the MAC length of a split GSO skb (L2+L3+L4+payload), and the names get confusing, so rename skb_gso_validate_mtu to skb_gso_validate_network_len Signed-off-by: Daniel Axtens <dja@axtens.net> Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman2017-11-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ipv4: allow local fragmentation in ip_finish_output_gso()Lance Richardson2016-11-031-1/+1
| | | | | | | | | | | | | | | | | | | | | Some configurations (e.g. geneve interface with default MTU of 1500 over an ethernet interface with 1500 MTU) result in the transmission of packets that exceed the configured MTU. While this should be considered to be a "bad" configuration, it is still allowed and should not result in the sending of packets that exceed the configured MTU. Fix by dropping the assumption in ip_finish_output_gso() that locally originated gso packets will never need fragmentation. Basic testing using iperf (observing CPU usage and bandwidth) have shown no measurable performance impact for traffic not requiring fragmentation. Fixes: c7ba65d7b649 ("net: ip: push gso skb forwarding handling down the stack") Reported-by: Jan Tluka <jtluka@redhat.com> Signed-off-by: Lance Richardson <lrichard@redhat.com> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* net/ipv4: Introduce IPSKB_FRAG_SEGS bit to inet_skb_parm.flagsShmulik Ladkani2016-07-191-1/+1
| | | | | | | | | | | | | This flag indicates whether fragmentation of segments is allowed. Formerly this policy was hardcoded according to IPSKB_FORWARDED (set by either ip_forward or ipmr_forward). Cc: Hannes Frederic Sowa <hannes@stressinduktion.org> Cc: Florian Westphal <fw@strlen.de> Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* skbuff: introduce skb_gso_validate_mtuMarcelo Ricardo Leitner2016-06-031-1/+1
| | | | | | | | | | | | | skb_gso_network_seglen is not enough for checking fragment sizes if skb is using GSO_BY_FRAGS as we have to check frag per frag. This patch introduces skb_gso_validate_mtu, based on the former, which will wrap the use case inside it as all calls to skb_gso_network_seglen were to validate if it fits on a given TMU, and improve the check. Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Tested-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: rename IP_ADD_STATS_BH()Eric Dumazet2016-04-271-1/+1
| | | | | | | Rename IP_ADD_STATS_BH() to __IP_ADD_STATS() Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: rename IP_INC_STATS_BH()Eric Dumazet2016-04-271-2/+2
| | | | | | | | Rename IP_INC_STATS_BH() to __IP_INC_STATS(), to better express this is used in non preemptible context. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: remove skb_sender_cpu_clear()WANG Cong2016-03-011-1/+0
| | | | | | | | | After commit 52bd2d62ce67 ("net: better skb->sender_cpu and skb->napi_id cohabitation") skb_sender_cpu_clear() becomes empty and can be removed. Cc: Eric Dumazet <edumazet@google.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Pass net into dst_output and remove dst_output_okfnEric W. Biederman2015-10-081-1/+1
| | | | | | | Replace dst_output_okfn with dst_output Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* netfilter: Pass net into okfnEric W. Biederman2015-09-171-2/+1
| | | | | | | | | | | | | | | | | | This is immediately motivated by the bridge code that chains functions that call into netfilter. Without passing net into the okfns the bridge code would need to guess about the best expression for the network namespace to process packets in. As net is frequently one of the first things computed in continuation functions after netfilter has done it's job passing in the desired network namespace is in many cases a code simplification. To support this change the function dst_output_okfn is introduced to simplify passing dst_output as an okfn. For the moment dst_output_okfn just silently drops the struct net. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* netfilter: Pass struct net into the netfilter hooksEric W. Biederman2015-09-171-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pass a network namespace parameter into the netfilter hooks. At the call site of the netfilter hooks the path a packet is taking through the network stack is well known which allows the network namespace to be easily and reliabily. This allows the replacement of magic code like "dev_net(state->in?:state->out)" that appears at the start of most netfilter hooks with "state->net". In almost all cases the network namespace passed in is derived from the first network device passed in, guaranteeing those paths will not see any changes in practice. The exceptions are: xfrm/xfrm_output.c:xfrm_output_resume() xs_net(skb_dst(skb)->xfrm) ipvs/ip_vs_xmit.c:ip_vs_nat_send_or_cont() ip_vs_conn_net(cp) ipvs/ip_vs_xmit.c:ip_vs_send_or_cont() ip_vs_conn_net(cp) ipv4/raw.c:raw_send_hdrinc() sock_net(sk) ipv6/ip6_output.c:ip6_xmit() sock_net(sk) ipv6/ndisc.c:ndisc_send_skb() dev_net(skb->dev) not dev_net(dst->dev) ipv6/raw.c:raw6_send_hdrinc() sock_net(sk) br_netfilter_hooks.c:br_nf_pre_routing_finish() dev_net(skb->dev) before skb->dev is set to nf_bridge->physindev In all cases these exceptions seem to be a better expression for the network namespace the packet is being processed in then the historic "dev_net(in?in:out)". I am documenting them in case something odd pops up and someone starts trying to track down what happened. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* ipv4: Compute net once in ip_forward_finishEric W. Biederman2015-09-171-2/+3
| | | | | Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* ipv4: Compute net once in ip_forwardEric W. Biederman2015-09-171-2/+4
| | | | | | | | Compute struct net from the input device in ip_forward before it is used. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Merge dst_output and dst_output_skEric W. Biederman2015-09-171-1/+1
| | | | | | | | | Add a sock paramter to dst_output making dst_output_sk superfluous. Add a skb->sk parameter to all of the callers of dst_output Have the callers of dst_output_sk call dst_output. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* ip: reject too-big defragmented DF-skb when forwardingFlorian Westphal2015-05-251-7/+11
| | | | | | | | | | | | | | Send icmp pmtu error if we find that the largest fragment of df-skb exceeded the output path mtu. The ip output path will still catch this later on but we can avoid the forward/postrouting hook traversal by rejecting right away. This is what ipv6 already does. Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
* ip_forward: Drop frames with attached skb->skSebastian Pöhn2015-04-201-0/+3
| | | | | | | | | | | | | | | | | | | Initial discussion was: [FYI] xfrm: Don't lookup sk_policy for timewait sockets Forwarded frames should not have a socket attached. Especially tw sockets will lead to panics later-on in the stack. This was observed with TPROXY assigning a tw socket and broken policy routing (misconfigured). As a result frame enters forwarding path instead of input. We cannot solve this in TPROXY as it cannot know that policy routing is broken. v2: Remove useless comment Signed-off-by: Sebastian Poehn <sebastian.poehn@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* netfilter: Pass socket pointer down through okfn().David Miller2015-04-071-4/+4
| | | | | | | | | | | | | | | | | | | On the output paths in particular, we have to sometimes deal with two socket contexts. First, and usually skb->sk, is the local socket that generated the frame. And second, is potentially the socket used to control a tunneling socket, such as one the encapsulates using UDP. We do not want to disassociate skb->sk when encapsulating in order to fix this, because that would break socket memory accounting. The most extreme case where this can cause huge problems is an AF_PACKET socket transmitting over a vxlan device. We hit code paths doing checks that assume they are dealing with an ipv4 socket, but are actually operating upon the AF_PACKET one. Signed-off-by: David S. Miller <davem@davemloft.net>
* xps: must clear sender_cpu before forwardingEric Dumazet2015-03-111-0/+1
| | | | | | | | | | | | | | | | | | John reported that my previous commit added a regression on his router. This is because sender_cpu & napi_id share a common location, so get_xps_queue() can see garbage and perform an out of bound access. We need to make sure sender_cpu is cleared before doing the transmit, otherwise any NIC busy poll enabled (skb_mark_napi_id()) can trigger this bug. Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: John <jw@nuclearfallout.net> Bisected-by: John <jw@nuclearfallout.net> Fixes: 2bd82484bb4c ("xps: fix xps for stacked devices") Signed-off-by: David S. Miller <davem@davemloft.net>
* ipv4: try to cache dst_entries which would cause a redirectHannes Frederic Sowa2015-01-261-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | Not caching dst_entries which cause redirects could be exploited by hosts on the same subnet, causing a severe DoS attack. This effect aggravated since commit f88649721268999 ("ipv4: fix dst race in sk_dst_get()"). Lookups causing redirects will be allocated with DST_NOCACHE set which will force dst_release to free them via RCU. Unfortunately waiting for RCU grace period just takes too long, we can end up with >1M dst_entries waiting to be released and the system will run OOM. rcuos threads cannot catch up under high softirq load. Attaching the flag to emit a redirect later on to the specific skb allows us to cache those dst_entries thus reducing the pressure on allocation and deallocation. This issue was discovered by Marcelo Leitner. Cc: Julian Anastasov <ja@ssi.bg> Signed-off-by: Marcelo Leitner <mleitner@redhat.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: rename local_df to ignore_dfWANG Cong2014-05-121-1/+1
| | | | | | | | | | | | | As suggested by several people, rename local_df to ignore_df, since it means "ignore df bit if it is set". Cc: Maciej Żenczykowski <maze@google.com> Cc: Florian Westphal <fw@strlen.de> Cc: David S. Miller <davem@davemloft.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Maciej Żenczykowski <maze@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: ip: push gso skb forwarding handling down the stackFlorian Westphal2014-05-071-50/+0
| | | | | | | | | | | | | | | | Doing the segmentation in the forward path has one major drawback: When using virtio, we may process gso udp packets coming from host network stack. In that case, netfilter POSTROUTING will see one packet with udp header followed by multiple ip fragments. Delay the segmentation and do it after POSTROUTING invocation to avoid this. Fixes: fe6cc55f3a9 ("net: ip, ipv6: handle gso skbs in forwarding path") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: ipv4: ip_forward: fix inverted local_df testFlorian Westphal2014-05-071-2/+2
| | | | | | | | | | | | | | | | | | | local_df means 'ignore DF bit if set', so if its set we're allowed to perform ip fragmentation. This wasn't noticed earlier because the output path also drops such skbs (and emits needed icmp error) and because netfilter ip defrag did not set local_df until couple of days ago. Only difference is that DF-packets-larger-than MTU now discarded earlier (f.e. we avoid pointless netfilter postrouting trip). While at it, drop the repeated test ip_exceeds_mtu, checking it once is enough... Fixes: fe6cc55f3a9 ("net: ip, ipv6: handle gso skbs in forwarding path") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2014-02-191-2/+69
|\ | | | | | | | | | | | | | | | | | | | | Conflicts: drivers/net/bonding/bond_3ad.h drivers/net/bonding/bond_main.c Two minor conflicts in bonding, both of which were overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
| * net: ip, ipv6: handle gso skbs in forwarding pathFlorian Westphal2014-02-131-2/+69
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Marcelo Ricardo Leitner reported problems when the forwarding link path has a lower mtu than the incoming one if the inbound interface supports GRO. Given: Host <mtu1500> R1 <mtu1200> R2 Host sends tcp stream which is routed via R1 and R2. R1 performs GRO. In this case, the kernel will fail to send ICMP fragmentation needed messages (or pkt too big for ipv6), as GSO packets currently bypass dstmtu checks in forward path. Instead, Linux tries to send out packets exceeding the mtu. When locking route MTU on Host (i.e., no ipv4 DF bit set), R1 does not fragment the packets when forwarding, and again tries to send out packets exceeding R1-R2 link mtu. This alters the forwarding dstmtu checks to take the individual gso segment lengths into account. For ipv6, we send out pkt too big error for gso if the individual segments are too big. For ipv4, we either send icmp fragmentation needed, or, if the DF bit is not set, perform software segmentation and let the output path create fragments when the packet is leaving the machine. It is not 100% correct as the error message will contain the headers of the GRO skb instead of the original/segmented one, but it seems to work fine in my (limited) tests. Eric Dumazet suggested to simply shrink mss via ->gso_size to avoid sofware segmentation. However it turns out that skb_segment() assumes skb nr_frags is related to mss size so we would BUG there. I don't want to mess with it considering Herbert and Eric disagree on what the correct behavior should be. Hannes Frederic Sowa notes that when we would shrink gso_size skb_segment would then also need to deal with the case where SKB_MAX_FRAGS would be exceeded. This uses sofware segmentation in the forward path when we hit ipv4 non-DF packets and the outgoing link mtu is too small. Its not perfect, but given the lack of bug reports wrt. GRO fwd being broken this is a rare case anyway. Also its not like this could not be improved later once the dust settles. Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Reported-by: Marcelo Ricardo Leitner <mleitner@redhat.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
* | ipv4: ip_forward: perform skb->pkt_type check at the beginningDenis Kirjanov2014-02-131-3/+4
|/ | | | | | | | | | Packets which have L2 address different from ours should be already filtered before entering into ip_forward(). Perform that check at the beginning to avoid processing such packets. Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* ipv4: introduce ip_dst_mtu_maybe_forward and protect forwarding path against ↵Hannes Frederic Sowa2014-01-131-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | pmtu spoofing While forwarding we should not use the protocol path mtu to calculate the mtu for a forwarded packet but instead use the interface mtu. We mark forwarded skbs in ip_forward with IPSKB_FORWARDED, which was introduced for multicast forwarding. But as it does not conflict with our usage in unicast code path it is perfect for reuse. I moved the functions ip_sk_accept_pmtu, ip_sk_use_pmtu and ip_skb_dst_mtu along with the new ip_dst_mtu_maybe_forward to net/ip.h to fix circular dependencies because of IPSKB_FORWARDED. Because someone might have written a software which does probe destinations manually and expects the kernel to honour those path mtus I introduced a new per-namespace "ip_forward_use_pmtu" knob so someone can disable this new behaviour. We also still use mtus which are locked on a route for forwarding. The reason for this change is, that path mtus information can be injected into the kernel via e.g. icmp_err protocol handler without verification of local sockets. As such, this could cause the IPv4 forwarding path to wrongfully emit fragmentation needed notifications or start to fragment packets along a path. Tunnel and ipsec output paths clear IPCB again, thus IPSKB_FORWARDED won't be set and further fragmentation logic will use the path mtu to determine the fragmentation size. They also recheck packet size with help of path mtu discovery and report appropriate errors. Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: David Miller <davem@davemloft.net> Cc: John Heffner <johnwheffner@gmail.com> Cc: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* ipv4: introduce rt_uses_gatewayJulian Anastasov2012-10-081-1/+1
| | | | | | | | | | | | | | | | Add new flag to remember when route is via gateway. We will use it to allow rt_gateway to contain address of directly connected host for the cases when DST_NOCACHE is used or when the NH exception caches per-destination route without DST_NOCACHE flag, i.e. when routes are not used for other destinations. By this way we force the neighbour resolving to work with the routed destination but we can use different address in the packet, feature needed for IPVS-DR where original packet for virtual IP is routed via route to real IP. Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: David S. Miller <davem@davemloft.net>
* ipv4: fix forwarding for strict source routesJulian Anastasov2012-10-081-1/+1
| | | | | | | | | | After the change "Adjust semantics of rt->rt_gateway" (commit f8126f1d51) rt_gateway can be 0 but ip_forward() compares it directly with nexthop. What we want here is to check if traffic is to directly connected nexthop and to fail if using gateway. Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: David S. Miller <davem@davemloft.net>
* snmp: fix OutOctets counter to include forwarded datagramsVincent Bernat2012-06-071-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | RFC 4293 defines ipIfStatsOutOctets (similar definition for ipSystemStatsOutOctets): The total number of octets in IP datagrams delivered to the lower layers for transmission. Octets from datagrams counted in ipIfStatsOutTransmits MUST be counted here. And ipIfStatsOutTransmits: The total number of IP datagrams that this entity supplied to the lower layers for transmission. This includes datagrams generated locally and those forwarded by this entity. Therefore, IPSTATS_MIB_OUTOCTETS must be incremented when incrementing IPSTATS_MIB_OUTFORWDATAGRAMS. IP_UPD_PO_STATS is not used since ipIfStatsOutRequests must not include forwarded datagrams: The total number of IP datagrams that local IP user-protocols (including ICMP) supplied to IP in requests for transmission. Note that this counter does not include any datagrams counted in ipIfStatsOutForwDatagrams. Signed-off-by: Vincent Bernat <bernat@luffy.cx> Signed-off-by: David S. Miller <davem@davemloft.net>
* ipv4: fix checkpatch errorsDaniel Baluta2012-04-151-2/+2
| | | | | | | | | Fix checkpatch errors of the following type: * ERROR: "foo * bar" should be "foo *bar" * ERROR: "(foo*)" should be "(foo *)" Signed-off-by: Daniel Baluta <dbaluta@ixiacom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* ipv4: Save nexthop address of LSRR/SSRR option to IPCB.Li Wei2011-11-231-1/+1
| | | | | | | | | | | | | We can not update iph->daddr in ip_options_rcv_srr(), It is too early. When some exception ocurred later (eg. in ip_forward() when goto sr_failed) we need the ip header be identical to the original one as ICMP need it. Add a field 'nexthop' in struct ip_options to save nexthop of LSRR or SSRR option. Signed-off-by: Li Wei <lw@cn.fujitsu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* ipv4: Fix 'iph' use before set.David S. Miller2011-05-121-1/+1
| | | | | | | | | | | I swear none of my compilers warned about this, yet it is so obvious. > net/ipv4/ip_forward.c: In function 'ip_forward': > net/ipv4/ip_forward.c:87: warning: 'iph' may be used uninitialized in this function Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
* ipv4: Elide use of rt->rt_dst in ip_forward()David S. Miller2011-05-121-1/+1
| | | | | | | | | No matter what kind of header mangling occurs due to IP options processing, rt->rt_dst will always equal iph->daddr in the packet. So we can safely use iph->daddr instead of rt->rt_dst here. Signed-off-by: David S. Miller <davem@davemloft.net>
* net-next: remove useless union keywordChangli Gao2010-06-101-5/+5
| | | | | | | | | | remove useless union keyword in rtable, rt6_info and dn_route. Since there is only one member in a union, the union keyword isn't useful. Signed-off-by: Changli Gao <xiaosuo@gmail.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge branch 'master' of /repos/git/net-next-2.6Patrick McHardy2010-04-201-0/+1
|\ | | | | | | | | | | | | | | | | Conflicts: Documentation/feature-removal-schedule.txt net/ipv6/netfilter/ip6t_REJECT.c net/netfilter/xt_limit.c Signed-off-by: Patrick McHardy <kaber@trash.net>
| * include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo2010-03-301-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
* | netfilter: ipv4: use NFPROTO values for NF_HOOK invocationJan Engelhardt2010-03-251-2/+2
|/ | | | | | | | | | | | | | | | | The semantic patch that was used: // <smpl> @@ @@ (NF_HOOK |NF_HOOK_COND |nf_hook )( -PF_INET, +NFPROTO_IPV4, ...) // </smpl> Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
* net: skb->dst accessorsEric Dumazet2009-06-031-2/+2
| | | | | | | | | | | | | | | | | | Define three accessors to get/set dst attached to a skb struct dst_entry *skb_dst(const struct sk_buff *skb) void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst) void skb_dst_drop(struct sk_buff *skb) This one should replace occurrences of : dst_release(skb->dst) skb->dst = NULL; Delete skb->dst field Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: skb->rtable accessorEric Dumazet2009-06-031-1/+1
| | | | | | | | | | | Define skb_rtable(const struct sk_buff *skb) accessor to get rtable from skb Delete skb->rtable field Setting rtable is not allowed, just set dst instead as rtable is an alias. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: reduce structures when XFRM=nAlexey Dobriyan2008-10-281-1/+1
| | | | | | | | | | ifdef out * struct sk_buff::sp (pointer) * struct dst_entry::xfrm (pointer) * struct sock::sk_policy (2 pointers) Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* mib: add net to IP_INC_STATS_BHPavel Emelyanov2008-07-161-2/+2
| | | | | Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* mib: add net to IP_INC_STATSPavel Emelyanov2008-07-161-1/+1
| | | | | | | | All the callers already have either the net itself, or the place where to get it from. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Discard and warn about LRO'd skbs received for forwardingBen Hutchings2008-06-191-0/+3
| | | | | | | | | | | Add skb_warn_if_lro() to test whether an skb was received with LRO and warn if so. Change br_forward(), ip_forward() and ip6_forward() to call it) and discard the skb if it returns true. Signed-off-by: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: remove CVS keywordsAdrian Bunk2008-06-111-2/+0
| | | | | | | | This patch removes CVS keywords that weren't updated for a long time from comments. Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
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