kernel/linux.git/include/net/dst.h, branch v5.14.8

net: Consolidate common blackhole dst ops

2021-03-10T20:24:18+00:00

Move generic blackhole dst ops to the core and use them from both ipv4_dst_blackhole_ops and ip6_dst_blackhole_ops where possible. No functional change otherwise. We need these also in other locations and having to define them over and over again is not great. Signed-off-by: Daniel Borkmann Signed-off-by: David S. Miller

net: indirect call helpers for ipv4/ipv6 dst_check functions

2021-02-03T22:51:40+00:00

This patch avoids the indirect call for the common case: ip6_dst_check and ipv4_dst_check Signed-off-by: Brian Vazquez Signed-off-by: Jakub Kicinski

net: use indirect call helpers for dst_mtu

2021-02-03T22:51:39+00:00

This patch avoids the indirect call for the common case: ip6_mtu and ipv4_mtu Signed-off-by: Brian Vazquez Signed-off-by: Jakub Kicinski

net: use indirect call helpers for dst_output

2021-02-03T22:51:39+00:00

This patch avoids the indirect call for the common case: ip6_output and ip_output Signed-off-by: Brian Vazquez Signed-off-by: Jakub Kicinski

net: use indirect call helpers for dst_input

2021-02-03T22:51:39+00:00

This patch avoids the indirect call for the common case: ip_local_deliver and ip6_input Signed-off-by: Brian Vazquez Signed-off-by: Jakub Kicinski

mpls: drop skb's dst in mpls_forward()

2020-11-03T20:55:53+00:00

Commit 394de110a733 ("net: Added pointer check for dst->ops->neigh_lookup in dst_neigh_lookup_skb") added a test in dst_neigh_lookup_skb() to avoid a NULL pointer dereference. The root cause was the MPLS forwarding code, which doesn't call skb_dst_drop() on incoming packets. That is, if the packet is received from a collect_md device, it has a metadata_dst attached to it that doesn't implement any dst_ops function. To align the MPLS behaviour with IPv4 and IPv6, let's drop the dst in mpls_forward(). This way, dst_neigh_lookup_skb() doesn't need to test ->neigh_lookup any more. Let's keep a WARN condition though, to document the precondition and to ease detection of such problems in the future. Signed-off-by: Guillaume Nault Link: https://lore.kernel.org/r/f8c2784c13faa54469a2aac339470b1049ca6b63.1604102750.git.gnault@redhat.com Signed-off-by: Jakub Kicinski

net: clean up codestyle

2020-08-31T19:33:34+00:00

This is a pure codestyle cleanup patch. No functional change intended. Signed-off-by: Miaohe Lin Signed-off-by: David S. Miller

tunnels: PMTU discovery support for directly bridged IP packets

2020-08-04T20:01:45+00:00

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 Reviewed-by: David Ahern Signed-off-by: David S. Miller

net: Added pointer check for dst->ops->neigh_lookup in dst_neigh_lookup_skb

2020-07-07T22:33:28+00:00

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] [ 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] [ 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 Signed-off-by: David S. Miller

Remove DST_HOST

2020-03-24T04:57:44+00:00

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 Acked-by: David Ahern Signed-off-by: David S. Miller