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2020-08-31net: clean up codestyleMiaohe Lin1-1/+1
This is a pure codestyle cleanup patch. No functional change intended. Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-04tunnels: PMTU discovery support for directly bridged IP packetsStefano Brivio1-10/+0
It's currently possible to bridge Ethernet tunnels carrying IP packets directly to external interfaces without assigning them addresses and routes on the bridged network itself: this is the case for UDP tunnels bridged with a standard bridge or by Open vSwitch. PMTU discovery is currently broken with those configurations, because the encapsulation effectively decreases the MTU of the link, and while we are able to account for this using PMTU discovery on the lower layer, we don't have a way to relay ICMP or ICMPv6 messages needed by the sender, because we don't have valid routes to it. On the other hand, as a tunnel endpoint, we can't fragment packets as a general approach: this is for instance clearly forbidden for VXLAN by RFC 7348, section 4.3: VTEPs MUST NOT fragment VXLAN packets. Intermediate routers may fragment encapsulated VXLAN packets due to the larger frame size. The destination VTEP MAY silently discard such VXLAN fragments. The same paragraph recommends that the MTU over the physical network accomodates for encapsulations, but this isn't a practical option for complex topologies, especially for typical Open vSwitch use cases. Further, it states that: Other techniques like Path MTU discovery (see [RFC1191] and [RFC1981]) MAY be used to address this requirement as well. Now, PMTU discovery already works for routed interfaces, we get route exceptions created by the encapsulation device as they receive ICMP Fragmentation Needed and ICMPv6 Packet Too Big messages, and we already rebuild those messages with the appropriate MTU and route them back to the sender. Add the missing bits for bridged cases: - checks in skb_tunnel_check_pmtu() to understand if it's appropriate to trigger a reply according to RFC 1122 section 3.2.2 for ICMP and RFC 4443 section 2.4 for ICMPv6. This function is already called by UDP tunnels - a new function generating those ICMP or ICMPv6 replies. We can't reuse icmp_send() and icmp6_send() as we don't see the sender as a valid destination. This doesn't need to be generic, as we don't cover any other type of ICMP errors given that we only provide an encapsulation function to the sender While at it, make the MTU check in skb_tunnel_check_pmtu() accurate: we might receive GSO buffers here, and the passed headroom already includes the inner MAC length, so we don't have to account for it a second time (that would imply three MAC headers on the wire, but there are just two). This issue became visible while bridging IPv6 packets with 4500 bytes of payload over GENEVE using IPv4 with a PMTU of 4000. Given the 50 bytes of encapsulation headroom, we would advertise MTU as 3950, and we would reject fragmented IPv6 datagrams of 3958 bytes size on the wire. We're exclusively dealing with network MTU here, though, so we could get Ethernet frames up to 3964 octets in that case. v2: - moved skb_tunnel_check_pmtu() to ip_tunnel_core.c (David Ahern) - split IPv4/IPv6 functions (David Ahern) Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-07net: Added pointer check for dst->ops->neigh_lookup in dst_neigh_lookup_skbMartin Varghese1-1/+9
The packets from tunnel devices (eg bareudp) may have only metadata in the dst pointer of skb. Hence a pointer check of neigh_lookup is needed in dst_neigh_lookup_skb Kernel crashes when packets from bareudp device is processed in the kernel neighbour subsytem. [ 133.384484] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 133.385240] #PF: supervisor instruction fetch in kernel mode [ 133.385828] #PF: error_code(0x0010) - not-present page [ 133.386603] PGD 0 P4D 0 [ 133.386875] Oops: 0010 [#1] SMP PTI [ 133.387275] CPU: 0 PID: 5045 Comm: ping Tainted: G W 5.8.0-rc2+ #15 [ 133.388052] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 [ 133.391076] RIP: 0010:0x0 [ 133.392401] Code: Bad RIP value. [ 133.394029] RSP: 0018:ffffb79980003d50 EFLAGS: 00010246 [ 133.396656] RAX: 0000000080000102 RBX: ffff9de2fe0d6600 RCX: ffff9de2fe5e9d00 [ 133.399018] RDX: 0000000000000000 RSI: ffff9de2fe5e9d00 RDI: ffff9de2fc21b400 [ 133.399685] RBP: ffff9de2fe5e9d00 R08: 0000000000000000 R09: 0000000000000000 [ 133.400350] R10: ffff9de2fbc6be22 R11: ffff9de2fe0d6600 R12: ffff9de2fc21b400 [ 133.401010] R13: ffff9de2fe0d6628 R14: 0000000000000001 R15: 0000000000000003 [ 133.401667] FS: 00007fe014918740(0000) GS:ffff9de2fec00000(0000) knlGS:0000000000000000 [ 133.402412] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 133.402948] CR2: ffffffffffffffd6 CR3: 000000003bb72000 CR4: 00000000000006f0 [ 133.403611] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 133.404270] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 133.404933] Call Trace: [ 133.405169] <IRQ> [ 133.405367] __neigh_update+0x5a4/0x8f0 [ 133.405734] arp_process+0x294/0x820 [ 133.406076] ? __netif_receive_skb_core+0x866/0xe70 [ 133.406557] arp_rcv+0x129/0x1c0 [ 133.406882] __netif_receive_skb_one_core+0x95/0xb0 [ 133.407340] process_backlog+0xa7/0x150 [ 133.407705] net_rx_action+0x2af/0x420 [ 133.408457] __do_softirq+0xda/0x2a8 [ 133.408813] asm_call_on_stack+0x12/0x20 [ 133.409290] </IRQ> [ 133.409519] do_softirq_own_stack+0x39/0x50 [ 133.410036] do_softirq+0x50/0x60 [ 133.410401] __local_bh_enable_ip+0x50/0x60 [ 133.410871] ip_finish_output2+0x195/0x530 [ 133.411288] ip_output+0x72/0xf0 [ 133.411673] ? __ip_finish_output+0x1f0/0x1f0 [ 133.412122] ip_send_skb+0x15/0x40 [ 133.412471] raw_sendmsg+0x853/0xab0 [ 133.412855] ? insert_pfn+0xfe/0x270 [ 133.413827] ? vvar_fault+0xec/0x190 [ 133.414772] sock_sendmsg+0x57/0x80 [ 133.415685] __sys_sendto+0xdc/0x160 [ 133.416605] ? syscall_trace_enter+0x1d4/0x2b0 [ 133.417679] ? __audit_syscall_exit+0x1d9/0x280 [ 133.418753] ? __prepare_exit_to_usermode+0x5d/0x1a0 [ 133.419819] __x64_sys_sendto+0x24/0x30 [ 133.420848] do_syscall_64+0x4d/0x90 [ 133.421768] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 133.422833] RIP: 0033:0x7fe013689c03 [ 133.423749] Code: Bad RIP value. [ 133.424624] RSP: 002b:00007ffc7288f418 EFLAGS: 00000246 ORIG_RAX: 000000000000002c [ 133.425940] RAX: ffffffffffffffda RBX: 000056151fc63720 RCX: 00007fe013689c03 [ 133.427225] RDX: 0000000000000040 RSI: 000056151fc63720 RDI: 0000000000000003 [ 133.428481] RBP: 00007ffc72890b30 R08: 000056151fc60500 R09: 0000000000000010 [ 133.429757] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000040 [ 133.431041] R13: 000056151fc636e0 R14: 000056151fc616bc R15: 0000000000000080 [ 133.432481] Modules linked in: mpls_iptunnel act_mirred act_tunnel_key cls_flower sch_ingress veth mpls_router ip_tunnel bareudp ip6_udp_tunnel udp_tunnel macsec udp_diag inet_diag unix_diag af_packet_diag netlink_diag binfmt_misc xt_MASQUERADE iptable_nat xt_addrtype xt_conntrack nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 br_netfilter bridge stp llc ebtable_filter ebtables overlay ip6table_filter ip6_tables iptable_filter sunrpc ext4 mbcache jbd2 pcspkr i2c_piix4 virtio_balloon joydev ip_tables xfs libcrc32c ata_generic qxl pata_acpi drm_ttm_helper ttm drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops drm ata_piix libata virtio_net net_failover virtio_console failover virtio_blk i2c_core virtio_pci virtio_ring serio_raw floppy virtio dm_mirror dm_region_hash dm_log dm_mod [ 133.444045] CR2: 0000000000000000 [ 133.445082] ---[ end trace f4aeee1958fd1638 ]--- [ 133.446236] RIP: 0010:0x0 [ 133.447180] Code: Bad RIP value. [ 133.448152] RSP: 0018:ffffb79980003d50 EFLAGS: 00010246 [ 133.449363] RAX: 0000000080000102 RBX: ffff9de2fe0d6600 RCX: ffff9de2fe5e9d00 [ 133.450835] RDX: 0000000000000000 RSI: ffff9de2fe5e9d00 RDI: ffff9de2fc21b400 [ 133.452237] RBP: ffff9de2fe5e9d00 R08: 0000000000000000 R09: 0000000000000000 [ 133.453722] R10: ffff9de2fbc6be22 R11: ffff9de2fe0d6600 R12: ffff9de2fc21b400 [ 133.455149] R13: ffff9de2fe0d6628 R14: 0000000000000001 R15: 0000000000000003 [ 133.456520] FS: 00007fe014918740(0000) GS:ffff9de2fec00000(0000) knlGS:0000000000000000 [ 133.458046] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 133.459342] CR2: ffffffffffffffd6 CR3: 000000003bb72000 CR4: 00000000000006f0 [ 133.460782] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 133.462240] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 133.463697] Kernel panic - not syncing: Fatal exception in interrupt [ 133.465226] Kernel Offset: 0xfa00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) [ 133.467025] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]--- Fixes: aaa0c23cb901 ("Fix dst_neigh_lookup/dst_neigh_lookup_skb return value handling bug") Signed-off-by: Martin Varghese <martin.varghese@nokia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-23Remove DST_HOSTDavid Laight1-1/+0
Previous changes to the IP routing code have removed all the tests for the DS_HOST route flag. Remove the flags and all the code that sets it. Signed-off-by: David Laight <david.laight@aculab.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-24net/dst: do not confirm neighbor for vxlan and geneve pmtu updateHangbin Liu1-1/+1
When do IPv6 tunnel PMTU update and calls __ip6_rt_update_pmtu() in the end, we should not call dst_confirm_neigh() as there is no two-way communication. So disable the neigh confirm for vxlan and geneve pmtu update. v5: No change. v4: No change. v3: Do not remove dst_confirm_neigh, but add a new bool parameter in dst_ops.update_pmtu to control whether we should do neighbor confirm. Also split the big patch to small ones for each area. v2: Remove dst_confirm_neigh in __ip6_rt_update_pmtu. Fixes: a93bf0ff4490 ("vxlan: update skb dst pmtu on tx path") Fixes: 52a589d51f10 ("geneve: update skb dst pmtu on tx path") Reviewed-by: Guillaume Nault <gnault@redhat.com> Tested-by: Guillaume Nault <gnault@redhat.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-24net/dst: add new function skb_dst_update_pmtu_no_confirmHangbin Liu1-0/+9
Add a new function skb_dst_update_pmtu_no_confirm() for callers who need update pmtu but should not do neighbor confirm. v5: No change. v4: No change. v3: Do not remove dst_confirm_neigh, but add a new bool parameter in dst_ops.update_pmtu to control whether we should do neighbor confirm. Also split the big patch to small ones for each area. v2: Remove dst_confirm_neigh in __ip6_rt_update_pmtu. Reviewed-by: Guillaume Nault <gnault@redhat.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-24net: add bool confirm_neigh parameter for dst_ops.update_pmtuHangbin Liu1-1/+1
The MTU update code is supposed to be invoked in response to real networking events that update the PMTU. In IPv6 PMTU update function __ip6_rt_update_pmtu() we called dst_confirm_neigh() to update neighbor confirmed time. But for tunnel code, it will call pmtu before xmit, like: - tnl_update_pmtu() - skb_dst_update_pmtu() - ip6_rt_update_pmtu() - __ip6_rt_update_pmtu() - dst_confirm_neigh() If the tunnel remote dst mac address changed and we still do the neigh confirm, we will not be able to update neigh cache and ping6 remote will failed. So for this ip_tunnel_xmit() case, _EVEN_ if the MTU is changed, we should not be invoking dst_confirm_neigh() as we have no evidence of successful two-way communication at this point. On the other hand it is also important to keep the neigh reachability fresh for TCP flows, so we cannot remove this dst_confirm_neigh() call. To fix the issue, we have to add a new bool parameter for dst_ops.update_pmtu to choose whether we should do neigh update or not. I will add the parameter in this patch and set all the callers to true to comply with the previous way, and fix the tunnel code one by one on later patches. v5: No change. v4: No change. v3: Do not remove dst_confirm_neigh, but add a new bool parameter in dst_ops.update_pmtu to control whether we should do neighbor confirm. Also split the big patch to small ones for each area. v2: Remove dst_confirm_neigh in __ip6_rt_update_pmtu. Suggested-by: David Miller <davem@davemloft.net> Reviewed-by: Guillaume Nault <gnault@redhat.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-20net: dst: Force 4-byte alignment of dst_metricsGeert Uytterhoeven1-1/+1
When storing a pointer to a dst_metrics structure in dst_entry._metrics, two flags are added in the least significant bits of the pointer value. Hence this assumes all pointers to dst_metrics structures have at least 4-byte alignment. However, on m68k, the minimum alignment of 32-bit values is 2 bytes, not 4 bytes. Hence in some kernel builds, dst_default_metrics may be only 2-byte aligned, leading to obscure boot warnings like: WARNING: CPU: 0 PID: 7 at lib/refcount.c:28 refcount_warn_saturate+0x44/0x9a refcount_t: underflow; use-after-free. Modules linked in: CPU: 0 PID: 7 Comm: ksoftirqd/0 Tainted: G W 5.5.0-rc2-atari-01448-g114a1a1038af891d-dirty #261 Stack from 10835e6c: 10835e6c 0038134f 00023fa6 00394b0f 0000001c 00000009 00321560 00023fea 00394b0f 0000001c 001a70f8 00000009 00000000 10835eb4 00000001 00000000 04208040 0000000a 00394b4a 10835ed4 00043aa8 001a70f8 00394b0f 0000001c 00000009 00394b4a 0026aba8 003215a4 00000003 00000000 0026d5a8 00000001 003215a4 003a4361 003238d6 000001f0 00000000 003215a4 10aa3b00 00025e84 003ddb00 10834000 002416a8 10aa3b00 00000000 00000080 000aa038 0004854a Call Trace: [<00023fa6>] __warn+0xb2/0xb4 [<00023fea>] warn_slowpath_fmt+0x42/0x64 [<001a70f8>] refcount_warn_saturate+0x44/0x9a [<00043aa8>] printk+0x0/0x18 [<001a70f8>] refcount_warn_saturate+0x44/0x9a [<0026aba8>] refcount_sub_and_test.constprop.73+0x38/0x3e [<0026d5a8>] ipv4_dst_destroy+0x5e/0x7e [<00025e84>] __local_bh_enable_ip+0x0/0x8e [<002416a8>] dst_destroy+0x40/0xae Fix this by forcing 4-byte alignment of all dst_metrics structures. Fixes: e5fd387ad5b30ca3 ("ipv6: do not overwrite inetpeer metrics prematurely") Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-07-01net: dst.h: Fix shifting signed 32-bit value by 31 bits problemVandana BN1-1/+1
Fix DST_FEATURE_ECN_CA to use "U" cast to avoid shifting signed 32-bit value by 31 bits problem. Signed-off-by: Vandana BN <bnvandana@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-29net: make skb_dst_force return true when dst is refcountedFlorian Westphal1-1/+4
netfilter did not expect that skb_dst_force() can cause skb to lose its dst entry. I got a bug report with a skb->dst NULL dereference in netfilter output path. The backtrace contains nf_reinject(), so the dst might have been cleared when skb got queued to userspace. Other users were fixed via if (skb_dst(skb)) { skb_dst_force(skb); if (!skb_dst(skb)) goto handle_err; } But I think its preferable to make the 'dst might be cleared' part of the function explicit. In netfilter case, skb with a null dst is expected when queueing in prerouting hook, so drop skb for the other hooks. v2: v1 of this patch returned true in case skb had no dst entry. Eric said: Say if we have two skb_dst_force() calls for some reason on the same skb, only the first one will return false. This now returns false even when skb had no dst, as per Erics suggestion, so callers might need to check skb_dst() first before skb_dst_force(). Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-21net: dst: remove gc leftoversJulian Wiedmann1-11/+0
Get rid of some obsolete gc-related documentation and macros that were missed in commit 5b7c9a8ff828 ("net: remove dst gc related code"). CC: Wei Wang <weiwan@google.com> Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Acked-by: Wei Wang <weiwan@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-17geneve, vxlan: Don't set exceptions if skb->len < mtuStefano Brivio1-0/+10
We shouldn't abuse exceptions: if the destination MTU is already higher than what we're transmitting, no exception should be created. Fixes: 52a589d51f10 ("geneve: update skb dst pmtu on tx path") Fixes: a93bf0ff4490 ("vxlan: update skb dst pmtu on tx path") Signed-off-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-20xfrm: Remove xfrmi interface ID from flowiBenedict Wong1-0/+14
In order to remove performance impact of having the extra u32 in every single flowi, this change removes the flowi_xfrm struct, prefering to take the if_id as a method parameter where needed. In the inbound direction, if_id is only needed during the __xfrm_check_policy() function, and the if_id can be determined at that point based on the skb. As such, xfrmi_decode_session() is only called with the skb in __xfrm_check_policy(). In the outbound direction, the only place where if_id is needed is the xfrm_lookup() call in xfrmi_xmit2(). With this change, the if_id is directly passed into the xfrm_lookup_with_ifid() call. All existing callers can still call xfrm_lookup(), which uses a default if_id of 0. This change does not change any behavior of XFRMIs except for improving overall system performance via flowi size reduction. This change has been tested against the Android Kernel Networking Tests: https://android.googlesource.com/kernel/tests/+/master/net/test Signed-off-by: Benedict Wong <benedictwong@google.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2018-03-05net: core: dst: Add kernel-doc for 'net' parameterJonathan Neuschäfer1-0/+1
This fixes the following kernel-doc warning: ./include/net/dst.h:366: warning: Function parameter or member 'net' not described in 'skb_tunnel_rx' Fixes: ea23192e8e57 ("tunnels: harmonize cleanup done on skb on rx path") Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-29Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-0/+8
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-25net: don't call update_pmtu unconditionallyNicolas Dichtel1-0/+8
Some dst_ops (e.g. md_dst_ops)) doesn't set this handler. It may result to: "BUG: unable to handle kernel NULL pointer dereference at (null)" Let's add a helper to check if update_pmtu is available before calling it. Fixes: 52a589d51f10 ("geneve: update skb dst pmtu on tx path") Fixes: a93bf0ff4490 ("vxlan: update skb dst pmtu on tx path") CC: Roman Kapl <code@rkapl.cz> CC: Xin Long <lucien.xin@gmail.com> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-30net: Remove dst->nextDavid Miller1-4/+0
There are no more users. Signed-off-by: David S. Miller <davem@davemloft.net> Reviewed-by: Eric Dumazet <edumazet@google.com>
2017-11-30net: Rearrange dst_entry layout to avoid useless padding.David Miller1-19/+12
We have padding to try and align the refcount on a separate cache line. But after several simplifications the padding has increased substantially. So now it's easy to change the layout to get rid of the padding entirely. We group the write-heavy __refcnt and __use with less often used items such as the rcu_head and the error code. Signed-off-by: David S. Miller <davem@davemloft.net> Reviewed-by: Eric Dumazet <edumazet@google.com>
2017-11-30xfrm: Move dst->path into struct xfrm_dstDavid Miller1-2/+1
The first member of an IPSEC route bundle chain sets it's dst->path to the underlying ipv4/ipv6 route that carries the bundle. Stated another way, if one were to follow the xfrm_dst->child chain of the bundle, the final non-NULL pointer would be the path and point to either an ipv4 or an ipv6 route. This is largely used to make sure that PMTU events propagate down to the correct ipv4 or ipv6 route. When we don't have the top of an IPSEC bundle 'dst->path == dst'. Move it down into xfrm_dst and key off of dst->xfrm. Signed-off-by: David S. Miller <davem@davemloft.net> Reviewed-by: Eric Dumazet <edumazet@google.com>
2017-11-30ipv6: Move dst->from into struct rt6_info.David Miller1-2/+1
The dst->from value is only used by ipv6 routes to track where a route "came from". Any time we clone or copy a core ipv6 route in the ipv6 routing tables, we have the copy/clone's ->from point to the base route. This is used to handle route expiration properly. Only ipv6 uses this mechanism, and only ipv6 code references it. So it is safe to move it into rt6_info. Signed-off-by: David S. Miller <davem@davemloft.net> Reviewed-by: Eric Dumazet <edumazet@google.com>
2017-11-30xfrm: Move child route linkage into xfrm_dst.David Miller1-2/+1
XFRM bundle child chains look like this: xdst1 --> xdst2 --> xdst3 --> path_dst All of xdstN are xfrm_dst objects and xdst->u.dst.xfrm is non-NULL. The final child pointer in the chain, here called 'path_dst', is some other kind of route such as an ipv4 or ipv6 one. The xfrm output path pops routes, one at a time, via the child pointer, until we hit one which has a dst->xfrm pointer which is NULL. We can easily preserve the above mechanisms with child sitting only in the xfrm_dst structure. All children in the chain before we break out of the xfrm_output() loop have dst->xfrm non-NULL and are therefore xfrm_dst objects. Since we break out of the loop when we find dst->xfrm NULL, we will not try to dereference 'dst' as if it were an xfrm_dst. Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-30ipv6: Move rt6_next from dst_entry into ipv6 route structure.David Miller1-1/+0
Signed-off-by: David S. Miller <davem@davemloft.net> Reviewed-by: Eric Dumazet <edumazet@google.com>
2017-11-30decnet: Move dn_next into decnet route structure.David Miller1-1/+0
Signed-off-by: David S. Miller <davem@davemloft.net> Reviewed-by: Eric Dumazet <edumazet@google.com>
2017-11-30net: dst->rt_next is unused.David Miller1-1/+0
Delete it. Signed-off-by: David S. Miller <davem@davemloft.net> Reviewed-by: Eric Dumazet <edumazet@google.com>
2017-11-04Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-0/+1
Files removed in 'net-next' had their license header updated in 'net'. We take the remove from 'net-next'. Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman1-0/+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>
2017-10-27net: updating dst lastusage is an unlikely event.Paolo Abeni1-1/+1
Since commit 0da4af00b2ed ("ipv6: only update __use and lastusetime once per jiffy at most"), updating the dst lastuse field is an unlikely action: it happens at most once per jiffy, out of potentially millions of calls per second. Mark explicitly the code as such, and let the compiler generate better code. Note: gcc 7.2 and several older versions do actually generate different - better - code when the unlikely() hint is in place, avoid jump in the fast path and keeping better code locality. Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-16ipv6: only update __use and lastusetime once per jiffy at mostWei Wang1-7/+8
In order to not dirty the cacheline too often, we try to only update dst->__use and dst->lastusetime at most once per jiffy. As dst->lastusetime is only used by ipv6 garbage collector, it should be good enough time resolution. And __use is only used in ipv6_route_seq_show() to show how many times a dst has been used. And as __use is not atomic_t right now, it does not show the precise number of usage times anyway. So we think it should be OK to only update it at most once per jiffy. According to my latest syn flood test on a machine with intel Xeon 6th gen processor and 2 10G mlx nics bonded together, each with 8 rx queues on 2 NUMA nodes: With this patch, the packet process rate increases from ~3.49Mpps to ~3.75Mpps with a 7% increase rate. Note: dst_use() is being renamed to dst_hold_and_use() to better specify the purpose of the function. Signed-off-by: Wei Wang <weiwan@google.com> Acked-by: Eric Dumazet <edumazet@googl.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-07ipv6: replace rwlock with rcu and spinlock in fib6_tableWei Wang1-1/+1
With all the preparation work before, we are now ready to replace rwlock with rcu and spinlock in fib6_table. That means now all fib6_node in fib6_table are protected by rcu. And when freeing fib6_node, call_rcu() is used to wait for the rcu grace period before releasing the memory. When accessing fib6_node, corresponding rcu APIs need to be used. And all previous sessions protected by the write lock will now be protected by the spin lock per table. All previous sessions protected by read lock will now be protected by rcu_read_lock(). A couple of things to note here: 1. As part of the work of replacing rwlock with rcu, the linked list of fn->leaf now has to be rcu protected as well. So both fn->leaf and rt->dst.rt6_next are now __rcu tagged and corresponding rcu APIs are used when manipulating them. 2. For fn->rr_ptr, first of all, it also needs to be rcu protected now and is tagged with __rcu and rcu APIs are used in corresponding places. Secondly, fn->rr_ptr is changed in rt6_select() which is a reader thread. This makes the issue a bit complicated. We think a valid solution for it is to let rt6_select() grab the tb6_lock if it decides to change it. As it is not in the normal operation and only happens when there is no valid neighbor cache for the route, we think the performance impact should be low. 3. fib6_walk_continue() has to be called with tb6_lock held even in the route dumping related functions, e.g. inet6_dump_fib(), fib6_tables_dump() and ipv6_route_seq_ops. It is because fib6_walk_continue() makes modifications to the walker structure, and so are fib6_repair_tree() and fib6_del_route(). In order to do proper syncing between them, we need to let fib6_walk_continue() hold the lock. We may be able to do further improvement on the way we do the tree walk to get rid of the need for holding the spin lock. But not for now. 4. When fib6_del_route() removes a route from the tree, we no longer mark rt->dst.rt6_next to NULL to make simultaneous reader be able to further traverse the list with rcu. However, rt->dst.rt6_next is only valid within this same rcu period. No one should access it later. 5. All the operation of atomic_inc(rt->rt6i_ref) is changed to be performed before we publish this route (either by linking it to fn->leaf or insert it in the list pointed by fn->leaf) just to be safe because as soon as we publish the route, some read thread will be able to access it. Signed-off-by: Wei Wang <weiwan@google.com> Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-21net: prevent dst uses after freeEric Dumazet1-18/+4
In linux-4.13, Wei worked hard to convert dst to a traditional refcounted model, removing GC. We now want to make sure a dst refcount can not transition from 0 back to 1. The problem here is that input path attached a not refcounted dst to an skb. Then later, because packet is forwarded and hits skb_dst_force() before exiting RCU section, we might try to take a refcount on one dst that is about to be freed, if another cpu saw 1 -> 0 transition in dst_release() and queued the dst for freeing after one RCU grace period. Lets unify skb_dst_force() and skb_dst_force_safe(), since we should always perform the complete check against dst refcount, and not assume it is not zero. Bugzilla : https://bugzilla.kernel.org/show_bug.cgi?id=197005 [ 989.919496] skb_dst_force+0x32/0x34 [ 989.919498] __dev_queue_xmit+0x1ad/0x482 [ 989.919501] ? eth_header+0x28/0xc6 [ 989.919502] dev_queue_xmit+0xb/0xd [ 989.919504] neigh_connected_output+0x9b/0xb4 [ 989.919507] ip_finish_output2+0x234/0x294 [ 989.919509] ? ipt_do_table+0x369/0x388 [ 989.919510] ip_finish_output+0x12c/0x13f [ 989.919512] ip_output+0x53/0x87 [ 989.919513] ip_forward_finish+0x53/0x5a [ 989.919515] ip_forward+0x2cb/0x3e6 [ 989.919516] ? pskb_trim_rcsum.part.9+0x4b/0x4b [ 989.919518] ip_rcv_finish+0x2e2/0x321 [ 989.919519] ip_rcv+0x26f/0x2eb [ 989.919522] ? vlan_do_receive+0x4f/0x289 [ 989.919523] __netif_receive_skb_core+0x467/0x50b [ 989.919526] ? tcp_gro_receive+0x239/0x239 [ 989.919529] ? inet_gro_receive+0x226/0x238 [ 989.919530] __netif_receive_skb+0x4d/0x5f [ 989.919532] netif_receive_skb_internal+0x5c/0xaf [ 989.919533] napi_gro_receive+0x45/0x81 [ 989.919536] ixgbe_poll+0xc8a/0xf09 [ 989.919539] ? kmem_cache_free_bulk+0x1b6/0x1f7 [ 989.919540] net_rx_action+0xf4/0x266 [ 989.919543] __do_softirq+0xa8/0x19d [ 989.919545] irq_exit+0x5d/0x6b [ 989.919546] do_IRQ+0x9c/0xb5 [ 989.919548] common_interrupt+0x93/0x93 [ 989.919548] </IRQ> Similarly dst_clone() can use dst_hold() helper to have additional debugging, as a follow up to commit 44ebe79149ff ("net: add debug atomic_inc_not_zero() in dst_hold()") In net-next we will convert dst atomic_t to refcount_t for peace of mind. Fixes: a4c2fd7f7891 ("net: remove DST_NOCACHE flag") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Wei Wang <weiwan@google.com> Reported-by: Paweł Staszewski <pstaszewski@itcare.pl> Bisected-by: Paweł Staszewski <pstaszewski@itcare.pl> Acked-by: Wei Wang <weiwan@google.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-18ipv4: convert dst_metrics.refcnt from atomic_t to refcount_tEric Dumazet1-1/+2
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-17net: add debug atomic_inc_not_zero() in dst_hold()Wei Wang1-1/+1
This patch is meant to add a debug warning on the situation where dst is being held during its destroy phase. This could potentially cause double free issue on the dst. Signed-off-by: Wei Wang <weiwan@google.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-17net: reorder all the dst flagsWei Wang1-5/+5
As some dst flags are removed, reorder the dst flags to fill in the blanks. Note: these flags are not exposed into user space. So it is safe to reorder. Signed-off-by: Wei Wang <weiwan@google.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-17net: remove DST_NOCACHE flagWei Wang1-1/+0
DST_NOCACHE flag check has been removed from dst_release() and dst_hold_safe() in a previous patch because all the dst are now ref counted properly and can be released based on refcnt only. Looking at the rest of the DST_NOCACHE use, all of them can now be removed or replaced with other checks. So this patch gets rid of all the DST_NOCACHE usage and remove this flag completely. Signed-off-by: Wei Wang <weiwan@google.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-17net: remove DST_NOGC flagWei Wang1-5/+1
Now that all the components have been changed to release dst based on refcnt only and not depend on dst gc anymore, we can remove the temporary flag DST_NOGC. Note that we also need to remove the DST_NOCACHE check in dst_release() and dst_hold_safe() because now all the dst are released based on refcnt and behaves as DST_NOCACHE. Signed-off-by: Wei Wang <weiwan@google.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-17net: remove dst gc related codeWei Wang1-21/+0
This patch removes all dst gc related code and all the dst free functions Signed-off-by: Wei Wang <weiwan@google.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-17xfrm: take refcnt of dst when creating struct xfrm_dst bundleWei Wang1-1/+0
During the creation of xfrm_dst bundle, always take ref count when allocating the dst. This way, xfrm_bundle_create() will form a linked list of dst with dst->child pointing to a ref counted dst child. And the returned dst pointer is also ref counted. This makes the link from the flow cache to this dst now ref counted properly. As the dst is always ref counted properly, we can safely mark DST_NOGC flag so dst_release() will release dst based on refcnt only. And dst gc is no longer needed and all dst_free() and its related function calls should be replaced with dst_release() or dst_release_immediate(). The special handling logic for dst->child in dst_destroy() can be replaced with a simple dst_release_immediate() call on the child to release the whole list linked by dst->child pointer. Previously used DST_NOHASH flag is not needed anymore as well. The reason that DST_NOHASH is used in the existing code is mainly to prevent the dst inserted in the fib tree to be wrongly destroyed during the deletion of the xfrm_dst bundle. So in the existing code, DST_NOHASH flag is marked in all the dst children except the one which is in the fib tree. However, with this patch series to remove dst gc logic and release dst only based on ref count, it is safe to release all the children from a xfrm_dst bundle as long as the dst children are all ref counted properly which is already the case in the existing code. So, this patch removes the use of DST_NOHASH flag. Signed-off-by: Wei Wang <weiwan@google.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-17net: introduce a new function dst_dev_put()Wei Wang1-0/+1
This function should be called when removing routes from fib tree after the dst gc is no longer in use. We first mark DST_OBSOLETE_DEAD on this dst to make sure next dst_ops->check() fails and returns NULL. Secondly, as we no longer keep the gc_list, we need to properly release dst->dev right at the moment when the dst is removed from the fib/fib6 tree. It does the following: 1. change dst->input and output pointers to dst_discard/dst_dscard_out to discard all packets 2. replace dst->dev with loopback interface Signed-off-by: Wei Wang <weiwan@google.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-17net: introduce DST_NOGC in dst_release() to destroy dst based on refcntWei Wang1-1/+4
The current mechanism of freeing dst is a bit complicated. dst has its ref count and when user grabs the reference to the dst, the ref count is properly taken in most cases except in IPv4/IPv6/decnet/xfrm routing code due to some historic reasons. If the reference to dst is always taken properly, we should be able to simplify the logic in dst_release() to destroy dst when dst->__refcnt drops from 1 to 0. And this should be the only condition to determine if we can call dst_destroy(). And as dst is always ref counted, there is no need for a dst garbage list to hold the dst entries that already get removed by the routing code but are still held by other users. And the task to periodically check the list to free dst if ref count become 0 is also not needed anymore. This patch introduces a temporary flag DST_NOGC(no garbage collector). If it is set in the dst, dst_release() will call dst_destroy() when dst->__refcnt drops to 0. dst_hold_safe() will also check for this flag and do atomic_inc_not_zero() similar as DST_NOCACHE to avoid double free issue. This temporary flag is mainly used so that we can make the transition component by component without breaking other parts. This flag will be removed after all components are properly transitioned. This patch also introduces a new function dst_release_immediate() which destroys dst without waiting on the rcu when refcnt drops to 0. It will be used in later patches. Follow-up patches will correct all the places to properly take ref count on dst and mark DST_NOGC. dst_release() or dst_release_immediate() will be used to release the dst instead of dst_free() and its related functions. And final clean-up patch will remove the DST_NOGC flag. Signed-off-by: Wei Wang <weiwan@google.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-26Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-1/+7
Overlapping changes in drivers/net/phy/marvell.c, bug fix in 'net' restricting a HW workaround alongside cleanups in 'net-next'. Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-26ipv4: add reference counting to metricsEric Dumazet1-1/+7
Andrey Konovalov reported crashes in ipv4_mtu() I could reproduce the issue with KASAN kernels, between 10.246.7.151 and 10.246.7.152 : 1) 20 concurrent netperf -t TCP_RR -H 10.246.7.152 -l 1000 & 2) At the same time run following loop : while : do ip ro add 10.246.7.152 dev eth0 src 10.246.7.151 mtu 1500 ip ro del 10.246.7.152 dev eth0 src 10.246.7.151 mtu 1500 done Cong Wang attempted to add back rt->fi in commit 82486aa6f1b9 ("ipv4: restore rt->fi for reference counting") but this proved to add some issues that were complex to solve. Instead, I suggested to add a refcount to the metrics themselves, being a standalone object (in particular, no reference to other objects) I tried to make this patch as small as possible to ease its backport, instead of being super clean. Note that we believe that only ipv4 dst need to take care of the metric refcount. But if this is wrong, this patch adds the basic infrastructure to extend this to other families. Many thanks to Julian Anastasov for reviewing this patch, and Cong Wang for his efforts on this problem. Fixes: 2860583fe840 ("ipv4: Kill rt->fi") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Julian Anastasov <ja@ssi.bg> Acked-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-18net: make struct dst_entry::dev first memberAlexey Dobriyan1-1/+1
struct dst_entry::dev is used most often. Move it so it can be accessed without imm8 offset on x86_64. add/remove: 0/0 grow/shrink: 9/239 up/down: 52/-413 (-361) function old new delta dst_rcu_free 126 138 +12 fnhe_flush_routes 211 219 +8 rt_set_nexthop 747 754 +7 rt_cache_route 85 91 +6 rt6_release 209 215 +6 dst_release 107 111 +4 dst_destroy_rcu 29 33 +4 dn_dst_check_expire 329 333 +4 dn_insert_route 484 485 +1 xfrm_resolve_and_create_bundle 2991 2990 -1 ... ip_route_me_harder 1163 1157 -6 __ip_append_data.isra 2730 2724 -6 ip6_forward 3052 3045 -7 callforward_do_filter 659 651 -8 dst_gc_task 571 549 -22 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-11net: rename dst_neigh_output back to neigh_outputJulian Anastasov1-12/+0
After the dst->pending_confirm flag was removed, we do not need anymore to provide dst arg to dst_neigh_output. So, rename it to neigh_output as before commit 5110effee8fd ("net: Do delayed neigh confirmation."). Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-07net: pending_confirm is not used anymoreJulian Anastasov1-12/+2
When same struct dst_entry can be used for many different neighbours we can not use it for pending confirmations. As last step, we can remove the pending_confirm flag. Reported-by: YueHaibing <yuehaibing@huawei.com> Fixes: 5110effee8fd ("net: Do delayed neigh confirmation.") Fixes: f2bb4bedf35d ("ipv4: Cache output routes in fib_info nexthops.") Signed-off-by: Julian Anastasov <ja@ssi.bg> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-07net: add confirm_neigh method to dst_opsJulian Anastasov1-0/+7
Add confirm_neigh method to dst_ops and use it from IPv4 and IPv6 to lookup and confirm the neighbour. Its usage via the new helper dst_confirm_neigh() should be restricted to MSG_PROBE users for performance reasons. For XFRM prefer the last tunnel address, if present. With help from Steffen Klassert. Signed-off-by: Julian Anastasov <ja@ssi.bg> Acked-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-25route: move lwtunnel state to a single placeJiri Benc1-4/+1
Commit 751a587ac9f9 ("route: fix breakage after moving lwtunnel state") moved lwtstate to the end of dst_entry for 32bit archs. This makes it share the cacheline with __refcnt which had an unkown effect on performance. For this reason, the pointer was kept in place for 64bit archs. However, later performance measurements showed this is of no concern. It turns out that every performance sensitive path that accesses lwtstate accesses also struct rtable or struct rt6_info which share the same cache line. Thus, to get rid of a few #ifdefs, move the field to the end of the struct also for 64bit. Signed-off-by: Jiri Benc <jbenc@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-18bpf, dst: add and use dst_tclassid helperDaniel Borkmann1-0/+12
We can just add a small helper dst_tclassid() for retrieving the dst->tclassid value. It makes the code a bit better in that we can get rid of the ifdef from filter.c by moving this into the header. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-14net: fix IP early demux racesEric Dumazet1-0/+33
David Wilder reported crashes caused by dst reuse. <quote David> I am seeing a crash on a distro V4.2.3 kernel caused by a double release of a dst_entry. In ipv4_dst_destroy() the call to list_empty() finds a poisoned next pointer, indicating the dst_entry has already been removed from the list and freed. The crash occurs 18 to 24 hours into a run of a network stress exerciser. </quote> Thanks to his detailed report and analysis, we were able to understand the core issue. IP early demux can associate a dst to skb, after a lookup in TCP/UDP sockets. When socket cache is not properly set, we want to store into sk->sk_dst_cache the dst for future IP early demux lookups, by acquiring a stable refcount on the dst. Problem is this acquisition is simply using an atomic_inc(), which works well, unless the dst was queued for destruction from dst_release() noticing dst refcount went to zero, if DST_NOCACHE was set on dst. We need to make sure current refcount is not zero before incrementing it, or risk double free as David reported. This patch, being a stable candidate, adds two new helpers, and use them only from IP early demux problematic paths. It might be possible to merge in net-next skb_dst_force() and skb_dst_force_safe(), but I prefer having the smallest patch for stable kernels : Maybe some skb_dst_force() callers do not expect skb->dst can suddenly be cleared. Can probably be backported back to linux-3.6 kernels Reported-by: David J. Wilder <dwilder@us.ibm.com> Tested-by: David J. Wilder <dwilder@us.ibm.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-08dst: Pass net into dst->outputEric W. Biederman1-4/+4
The network namespace is already passed into dst_output pass it into dst->output lwt->output and friends. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-08net: Pass net into dst_output and remove dst_output_okfnEric W. Biederman1-5/+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>