Add support for IFA_RT_PRIORITY to ipv6 addresses.

If the metric is changed on an existing address then the new route
is inserted before removing the old one. Since the metric is one
of the route keys, the prefix route can not be atomically replaced.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Update inet6_addr_modify to take ifa6_config argument versus a parameter
list. This is an argument move only; no functional change intended.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Move the creation of struct ifa6_config up to callers of inet6_addr_add.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Move config parameters for adding an ipv6 address to a struct. struct
names stem from inet6_rtm_newaddr which is the modern handler for
adding an address.

Start the conversion to ifa6_config with ipv6_add_addr. This is an argument
move only; no functional change intended. Mapping of variable changes:

    addr      -->  cfg->pfx
    peer_addr -->  cfg->peer_pfx
    pfxlen    -->  cfg->plen
    flags     -->  cfg->ifa_flags

scope, valid_lft, prefered_lft have the same names within cfg
(with corrected spelling).
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

the message be freed immediately, no need to trim it
back to the previous size.

Inspired by commit 7a9b3ec1 ("nl80211: remove unnecessary genlmsg_cancel() calls")
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit bb0ad198 ("ipv6: fib6_rules: support for match on sport, dport
and ip proto") added support for protocol and ports to FIB rules.
Update the FIB lookup tracepoint to dump the parameters.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds the End.BPF action to the LWT seg6local infrastructure.
This action works like any other seg6local End action, meaning that an IPv6
header with SRH is needed, whose DA has to be equal to the SID of the
action. It will also advance the SRH to the next segment, the BPF program
does not have to take care of this.

Since the BPF program may not be a source of instability in the kernel, it
is important to ensure that the integrity of the packet is maintained
before yielding it back to the IPv6 layer. The hook hence keeps track if
the SRH has been altered through the helpers, and re-validates its
content if needed with seg6_validate_srh. The state kept for validation is
stored in a per-CPU buffer. The BPF program is not allowed to directly
write into the packet, and only some fields of the SRH can be altered
through the helper bpf_lwt_seg6_store_bytes.

Performances profiling has shown that the SRH re-validation does not induce
a significant overhead. If the altered SRH is deemed as invalid, the packet
is dropped.

This validation is also done before executing any action through
bpf_lwt_seg6_action, and will not be performed again if the SRH is not
modified after calling the action.

The BPF program may return 3 types of return codes:
    - BPF_OK: the End.BPF action will look up the next destination through
             seg6_lookup_nexthop.
    - BPF_REDIRECT: if an action has been executed through the
          bpf_lwt_seg6_action helper, the BPF program should return this
          value, as the skb's destination is already set and the default
          lookup should not be performed.
    - BPF_DROP : the packet will be dropped.
Signed-off-by: NMathieu Xhonneux <m.xhonneux@gmail.com>
Acked-by: NDavid Lebrun <dlebrun@google.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

The BPF seg6local hook should be powerful enough to enable users to
implement most of the use-cases one could think of. After some thinking,
we figured out that the following actions should be possible on a SRv6
packet, requiring 3 specific helpers :
    - bpf_lwt_seg6_store_bytes: Modify non-sensitive fields of the SRH
    - bpf_lwt_seg6_adjust_srh: Allow to grow or shrink a SRH
                               (to add/delete TLVs)
    - bpf_lwt_seg6_action: Apply some SRv6 network programming actions
                           (specifically End.X, End.T, End.B6 and
                            End.B6.Encap)

The specifications of these helpers are provided in the patch (see
include/uapi/linux/bpf.h).

The non-sensitive fields of the SRH are the following : flags, tag and
TLVs. The other fields can not be modified, to maintain the SRH
integrity. Flags, tag and TLVs can easily be modified as their validity
can be checked afterwards via seg6_validate_srh. It is not allowed to
modify the segments directly. If one wants to add segments on the path,
he should stack a new SRH using the End.B6 action via
bpf_lwt_seg6_action.

Growing, shrinking or editing TLVs via the helpers will flag the SRH as
invalid, and it will have to be re-validated before re-entering the IPv6
layer. This flag is stored in a per-CPU buffer, along with the current
header length in bytes.

Storing the SRH len in bytes in the control block is mandatory when using
bpf_lwt_seg6_adjust_srh. The Header Ext. Length field contains the SRH
len rounded to 8 bytes (a padding TLV can be inserted to ensure the 8-bytes
boundary). When adding/deleting TLVs within the BPF program, the SRH may
temporary be in an invalid state where its length cannot be rounded to 8
bytes without remainder, hence the need to store the length in bytes
separately. The caller of the BPF program can then ensure that the SRH's
final length is valid using this value. Again, a final SRH modified by a
BPF program which doesn’t respect the 8-bytes boundary will be discarded
as it will be considered as invalid.

Finally, a fourth helper is provided, bpf_lwt_push_encap, which is
available from the LWT BPF IN hook, but not from the seg6local BPF one.
This helper allows to encapsulate a Segment Routing Header (either with
a new outer IPv6 header, or by inlining it directly in the existing IPv6
header) into a non-SRv6 packet. This helper is required if we want to
offer the possibility to dynamically encapsulate a SRH for non-SRv6 packet,
as the BPF seg6local hook only works on traffic already containing a SRH.
This is the BPF equivalent of the seg6 LWT infrastructure, which achieves
the same purpose but with a static SRH per route.

These helpers require CONFIG_IPV6=y (and not =m).
Signed-off-by: NMathieu Xhonneux <m.xhonneux@gmail.com>
Acked-by: NDavid Lebrun <dlebrun@google.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

The function lookup_nexthop is essential to implement most of the seg6local
actions. As we want to provide a BPF helper allowing to apply some of these
actions on the packet being processed, the helper should be able to call
this function, hence the need to make it public.

Moreover, if one argument is incorrect or if the next hop can not be found,
an error should be returned by the BPF helper so the BPF program can adapt
its processing of the packet (return an error, properly force the drop,
...). This patch hence makes this function return dst->error to indicate a
possible error.
Signed-off-by: NMathieu Xhonneux <m.xhonneux@gmail.com>
Acked-by: NDavid Lebrun <dlebrun@google.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

This is a followup to fib6 rules sport, dport and ipproto
match support. Only supports tcp, udp and icmp for ipproto.
Used by fib rule self tests.
Signed-off-by: NRoopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

UDP GSO delays final datagram construction to the GSO layer. This
conflicts with protocol transformations.

Fixes: bec1f6f6 ("udp: generate gso with UDP_SEGMENT")
CC: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In commit 47b7e7f8, this bit was removed at the same time the
RT6_LOOKUP_F_IFACE flag was removed. However, it is needed when
link-local addresses are used, which is a very common case: when
packets are routed, neighbor solicitations are done using link-local
addresses. For example, the following neighbor solicitation is not
matched by "-m rpfilter":

    IP6 fe80::5254:33ff:fe00:1 > ff02::1:ff00:3: ICMP6, neighbor
    solicitation, who has 2001:db8::5254:33ff:fe00:3, length 32

Commit 47b7e7f8 doesn't quite explain why we shouldn't use
RT6_LOOKUP_F_IFACE in the rpfilter case. I suppose the interface check
later in the function would make it redundant. However, the remaining
of the routing code is using RT6_LOOKUP_F_IFACE when there is no
source address (which matches rpfilter's case with a non-unicast
destination, like with neighbor solicitation).
Signed-off-by: NVincent Bernat <vincent@bernat.im>
Fixes: 47b7e7f8 ("netfilter: don't set F_IFACE on ipv6 fib lookups")
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Currently the packet rewrite and instantiation of nat NULL bindings
happens from the protocol specific nat backend.

Invocation occurs either via ip(6)table_nat or the nf_tables nat chain type.

Invocation looks like this (simplified):
NF_HOOK()
   |
   `---iptable_nat
	 |
	 `---> nf_nat_l3proto_ipv4 -> nf_nat_packet
	               |
          new packet? pass skb though iptables nat chain
                       |
		       `---> iptable_nat: ipt_do_table

In nft case, this looks the same (nft_chain_nat_ipv4 instead of
iptable_nat).

This is a problem for two reasons:
1. Can't use iptables nat and nf_tables nat at the same time,
   as the first user adds a nat binding (nf_nat_l3proto_ipv4 adds a
   NULL binding if do_table() did not find a matching nat rule so we
   can detect post-nat tuple collisions).
2. If you use e.g. nft_masq, snat, redir, etc. uses must also register
   an empty base chain so that the nat core gets called fro NF_HOOK()
   to do the reverse translation, which is neither obvious nor user
   friendly.

After this change, the base hook gets registered not from iptable_nat or
nftables nat hooks, but from the l3 nat core.

iptables/nft nat base hooks get registered with the nat core instead:

NF_HOOK()
   |
   `---> nf_nat_l3proto_ipv4 -> nf_nat_packet
		|
         new packet? pass skb through iptables/nftables nat chains
                |
		+-> iptables_nat: ipt_do_table
	        +-> nft nat chain x
	        `-> nft nat chain y

The nat core deals with null bindings and reverse translation.
When no mapping exists, it calls the registered nat lookup hooks until
one creates a new mapping.
If both iptables and nftables nat hooks exist, the first matching
one is used (i.e., higher priority wins).

Also, nft users do not need to create empty nat hooks anymore,
nat core always registers the base hooks that take care of reverse/reply
translation.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Will be used in followup patch when nat types no longer
use nf_register_net_hook() but will instead register with the nat core.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

The ip(6)tables nat table is currently receiving skbs from the netfilter
core, after a followup patch skbs will be coming from the netfilter nat
core instead, so the table is no longer backed by normal hook_ops.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Copy-pasted, both l3 helpers almost use same code here.
Split out the common part into an 'inet' helper.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Bring consistency to ipv6 route replace and append semantics.

Remove rt6_qualify_for_ecmp which is just guess work. It fails in 2 cases:
1. can not replace a route with a reject route. Existing code appends
   a new route instead of replacing the existing one.

2. can not have a multipath route where a leg uses a dev only nexthop

Existing use cases affected by this change:
1. adding a route with existing prefix and metric using NLM_F_CREATE
   without NLM_F_APPEND or NLM_F_EXCL (ie., what iproute2 calls
   'prepend'). Existing code auto-determines that the new nexthop can
   be appended to an existing route to create a multipath route. This
   change breaks that by requiring the APPEND flag for the new route
   to be added to an existing one. Instead the prepend just adds another
   route entry.

2. route replace. Existing code replaces first matching multipath route
   if new route is multipath capable and fallback to first matching
   non-ECMP route (reject or dev only route) in case one isn't available.
   New behavior replaces first matching route. (Thanks to Ido for spotting
   this one)

Note: Newer iproute2 is needed to display multipath routes with a dev-only
      nexthop. This is due to a bug in iproute2 and parsing nexthops.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Determine path MTU from a FIB lookup result. Logic is based on
ip6_dst_mtu_forward plus lookup of nexthop exception.

Add ip6_dst_mtu_forward to ipv6_stubs to handle access by core
bpf code.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Currently ip6gre and ip6erspan share single metadata mode device,
using 'collect_md_tun'.  Thus, when doing:
  ip link add dev ip6gre11 type ip6gretap external
  ip link add dev ip6erspan12 type ip6erspan external
  RTNETLINK answers: File exists
simply fails due to the 2nd tries to create the same collect_md_tun.

The patch fixes it by adding a separate collect md tunnel device
for the ip6erspan, 'collect_md_tun_erspan'.  As a result, a couple
of places need to refactor/split up in order to distinguish ip6gre
and ip6erspan.

First, move the collect_md check at ip6gre_tunnel_{unlink,link} and
create separate function {ip6gre,ip6ersapn}_tunnel_{link_md,unlink_md}.
Then before link/unlink, make sure the link_md/unlink_md is called.
Finally, a separate ndo_uninit is created for ip6erspan.  Tested it
using the samples/bpf/test_tunnel_bpf.sh.

Fixes: ef7baf5e ("ip6_gre: add ip6 erspan collect_md mode")
Signed-off-by: NWilliam Tu <u9012063@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Device features may change during transmission. In particular with
corking, a device may toggle scatter-gather in between allocating
and writing to an skb.

Do not unconditionally assume that !NETIF_F_SG at write time implies
that the same held at alloc time and thus the skb has sufficient
tailroom.

This issue predates git history.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Reported-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NWillem de Bruijn <willemb@google.com>
Reviewed-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Even though ip6erspan_tap_init() sets up hlen and tun_hlen according to
what ERSPAN needs, it goes ahead to call ip6gre_tnl_link_config() which
overwrites these settings with GRE-specific ones.

Similarly for changelink callbacks, which are handled by
ip6gre_changelink() calls ip6gre_tnl_change() calls
ip6gre_tnl_link_config() as well.

The difference ends up being 12 vs. 20 bytes, and this is generally not
a problem, because a 12-byte request likely ends up allocating more and
the extra 8 bytes are thus available. However correct it is not.

So replace the newlink and changelink callbacks with an ERSPAN-specific
ones, reusing the newly-introduced _common() functions.

Fixes: 5a963eb6 ("ip6_gre: Add ERSPAN native tunnel support")
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Acked-by: NWilliam Tu <u9012063@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Extract from ip6gre_changelink() a reusable function
ip6gre_changelink_common(). This will allow introduction of
ERSPAN-specific _changelink() function with not a lot of code
duplication.

Fixes: 5a963eb6 ("ip6_gre: Add ERSPAN native tunnel support")
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Acked-by: NWilliam Tu <u9012063@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Extract from ip6gre_newlink() a reusable function
ip6gre_newlink_common(). The ip6gre_tnl_link_config() call needs to be
made customizable for ERSPAN, thus reorder it with calls to
ip6_tnl_change_mtu() and dev_hold(), and extract the whole tail to the
caller, ip6gre_newlink(). Thus enable an ERSPAN-specific _newlink()
function without a lot of duplicity.

Fixes: 5a963eb6 ("ip6_gre: Add ERSPAN native tunnel support")
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Acked-by: NWilliam Tu <u9012063@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Split a reusable function ip6gre_tnl_copy_tnl_parm() from
ip6gre_tnl_change(). This will allow ERSPAN-specific code to
reuse the common parts while customizing the behavior for ERSPAN.

Fixes: 5a963eb6 ("ip6_gre: Add ERSPAN native tunnel support")
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Acked-by: NWilliam Tu <u9012063@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The function ip6gre_tnl_link_config() is used for setting up
configuration of both ip6gretap and ip6erspan tunnels. Split the
function into the common part and the route-lookup part. The latter then
takes the calculated header length as an argument. This split will allow
the patches down the line to sneak in a custom header length computation
for the ERSPAN tunnel.

Fixes: 5a963eb6 ("ip6_gre: Add ERSPAN native tunnel support")
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Acked-by: NWilliam Tu <u9012063@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

dev->needed_headroom is not primed until ip6_tnl_xmit(), so it starts
out zero. Thus the call to skb_cow_head() fails to actually make sure
there's enough headroom to push the ERSPAN headers to. That can lead to
the panic cited below. (Reproducer below that).

Fix by requesting either needed_headroom if already primed, or just the
bare minimum needed for the header otherwise.

[  190.703567] kernel BUG at net/core/skbuff.c:104!
[  190.708384] invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
[  190.714007] Modules linked in: act_mirred cls_matchall ip6_gre ip6_tunnel tunnel6 gre sch_ingress vrf veth x86_pkg_temp_thermal mlx_platform nfsd e1000e leds_mlxcpld
[  190.728975] CPU: 1 PID: 959 Comm: kworker/1:2 Not tainted 4.17.0-rc4-net_master-custom-139 #10
[  190.737647] Hardware name: Mellanox Technologies Ltd. "MSN2410-CB2F"/"SA000874", BIOS 4.6.5 03/08/2016
[  190.747006] Workqueue: ipv6_addrconf addrconf_dad_work
[  190.752222] RIP: 0010:skb_panic+0xc3/0x100
[  190.756358] RSP: 0018:ffff8801d54072f0 EFLAGS: 00010282
[  190.761629] RAX: 0000000000000085 RBX: ffff8801c1a8ecc0 RCX: 0000000000000000
[  190.768830] RDX: 0000000000000085 RSI: dffffc0000000000 RDI: ffffed003aa80e54
[  190.776025] RBP: ffff8801bd1ec5a0 R08: ffffed003aabce19 R09: ffffed003aabce19
[  190.783226] R10: 0000000000000001 R11: ffffed003aabce18 R12: ffff8801bf695dbe
[  190.790418] R13: 0000000000000084 R14: 00000000000006c0 R15: ffff8801bf695dc8
[  190.797621] FS:  0000000000000000(0000) GS:ffff8801d5400000(0000) knlGS:0000000000000000
[  190.805786] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  190.811582] CR2: 000055fa929aced0 CR3: 0000000003228004 CR4: 00000000001606e0
[  190.818790] Call Trace:
[  190.821264]  <IRQ>
[  190.823314]  ? ip6erspan_tunnel_xmit+0x5e4/0x1982 [ip6_gre]
[  190.828940]  ? ip6erspan_tunnel_xmit+0x5e4/0x1982 [ip6_gre]
[  190.834562]  skb_push+0x78/0x90
[  190.837749]  ip6erspan_tunnel_xmit+0x5e4/0x1982 [ip6_gre]
[  190.843219]  ? ip6gre_tunnel_ioctl+0xd90/0xd90 [ip6_gre]
[  190.848577]  ? debug_check_no_locks_freed+0x210/0x210
[  190.853679]  ? debug_check_no_locks_freed+0x210/0x210
[  190.858783]  ? print_irqtrace_events+0x120/0x120
[  190.863451]  ? sched_clock_cpu+0x18/0x210
[  190.867496]  ? cyc2ns_read_end+0x10/0x10
[  190.871474]  ? skb_network_protocol+0x76/0x200
[  190.875977]  dev_hard_start_xmit+0x137/0x770
[  190.880317]  ? do_raw_spin_trylock+0x6d/0xa0
[  190.884624]  sch_direct_xmit+0x2ef/0x5d0
[  190.888589]  ? pfifo_fast_dequeue+0x3fa/0x670
[  190.892994]  ? pfifo_fast_change_tx_queue_len+0x810/0x810
[  190.898455]  ? __lock_is_held+0xa0/0x160
[  190.902422]  __qdisc_run+0x39e/0xfc0
[  190.906041]  ? _raw_spin_unlock+0x29/0x40
[  190.910090]  ? pfifo_fast_enqueue+0x24b/0x3e0
[  190.914501]  ? sch_direct_xmit+0x5d0/0x5d0
[  190.918658]  ? pfifo_fast_dequeue+0x670/0x670
[  190.923047]  ? __dev_queue_xmit+0x172/0x1770
[  190.927365]  ? preempt_count_sub+0xf/0xd0
[  190.931421]  __dev_queue_xmit+0x410/0x1770
[  190.935553]  ? ___slab_alloc+0x605/0x930
[  190.939524]  ? print_irqtrace_events+0x120/0x120
[  190.944186]  ? memcpy+0x34/0x50
[  190.947364]  ? netdev_pick_tx+0x1c0/0x1c0
[  190.951428]  ? __skb_clone+0x2fd/0x3d0
[  190.955218]  ? __copy_skb_header+0x270/0x270
[  190.959537]  ? rcu_read_lock_sched_held+0x93/0xa0
[  190.964282]  ? kmem_cache_alloc+0x344/0x4d0
[  190.968520]  ? cyc2ns_read_end+0x10/0x10
[  190.972495]  ? skb_clone+0x123/0x230
[  190.976112]  ? skb_split+0x820/0x820
[  190.979747]  ? tcf_mirred+0x554/0x930 [act_mirred]
[  190.984582]  tcf_mirred+0x554/0x930 [act_mirred]
[  190.989252]  ? tcf_mirred_act_wants_ingress.part.2+0x10/0x10 [act_mirred]
[  190.996109]  ? __lock_acquire+0x706/0x26e0
[  191.000239]  ? sched_clock_cpu+0x18/0x210
[  191.004294]  tcf_action_exec+0xcf/0x2a0
[  191.008179]  tcf_classify+0xfa/0x340
[  191.011794]  __netif_receive_skb_core+0x8e1/0x1c60
[  191.016630]  ? debug_check_no_locks_freed+0x210/0x210
[  191.021732]  ? nf_ingress+0x500/0x500
[  191.025458]  ? process_backlog+0x347/0x4b0
[  191.029619]  ? print_irqtrace_events+0x120/0x120
[  191.034302]  ? lock_acquire+0xd8/0x320
[  191.038089]  ? process_backlog+0x1b6/0x4b0
[  191.042246]  ? process_backlog+0xc2/0x4b0
[  191.046303]  process_backlog+0xc2/0x4b0
[  191.050189]  net_rx_action+0x5cc/0x980
[  191.053991]  ? napi_complete_done+0x2c0/0x2c0
[  191.058386]  ? mark_lock+0x13d/0xb40
[  191.062001]  ? clockevents_program_event+0x6b/0x1d0
[  191.066922]  ? print_irqtrace_events+0x120/0x120
[  191.071593]  ? __lock_is_held+0xa0/0x160
[  191.075566]  __do_softirq+0x1d4/0x9d2
[  191.079282]  ? ip6_finish_output2+0x524/0x1460
[  191.083771]  do_softirq_own_stack+0x2a/0x40
[  191.087994]  </IRQ>
[  191.090130]  do_softirq.part.13+0x38/0x40
[  191.094178]  __local_bh_enable_ip+0x135/0x190
[  191.098591]  ip6_finish_output2+0x54d/0x1460
[  191.102916]  ? ip6_forward_finish+0x2f0/0x2f0
[  191.107314]  ? ip6_mtu+0x3c/0x2c0
[  191.110674]  ? ip6_finish_output+0x2f8/0x650
[  191.114992]  ? ip6_output+0x12a/0x500
[  191.118696]  ip6_output+0x12a/0x500
[  191.122223]  ? ip6_route_dev_notify+0x5b0/0x5b0
[  191.126807]  ? ip6_finish_output+0x650/0x650
[  191.131120]  ? ip6_fragment+0x1a60/0x1a60
[  191.135182]  ? icmp6_dst_alloc+0x26e/0x470
[  191.139317]  mld_sendpack+0x672/0x830
[  191.143021]  ? igmp6_mcf_seq_next+0x2f0/0x2f0
[  191.147429]  ? __local_bh_enable_ip+0x77/0x190
[  191.151913]  ipv6_mc_dad_complete+0x47/0x90
[  191.156144]  addrconf_dad_completed+0x561/0x720
[  191.160731]  ? addrconf_rs_timer+0x3a0/0x3a0
[  191.165036]  ? mark_held_locks+0xc9/0x140
[  191.169095]  ? __local_bh_enable_ip+0x77/0x190
[  191.173570]  ? addrconf_dad_work+0x50d/0xa20
[  191.177886]  ? addrconf_dad_work+0x529/0xa20
[  191.182194]  addrconf_dad_work+0x529/0xa20
[  191.186342]  ? addrconf_dad_completed+0x720/0x720
[  191.191088]  ? __lock_is_held+0xa0/0x160
[  191.195059]  ? process_one_work+0x45d/0xe20
[  191.199302]  ? process_one_work+0x51e/0xe20
[  191.203531]  ? rcu_read_lock_sched_held+0x93/0xa0
[  191.208279]  process_one_work+0x51e/0xe20
[  191.212340]  ? pwq_dec_nr_in_flight+0x200/0x200
[  191.216912]  ? get_lock_stats+0x4b/0xf0
[  191.220788]  ? preempt_count_sub+0xf/0xd0
[  191.224844]  ? worker_thread+0x219/0x860
[  191.228823]  ? do_raw_spin_trylock+0x6d/0xa0
[  191.233142]  worker_thread+0xeb/0x860
[  191.236848]  ? process_one_work+0xe20/0xe20
[  191.241095]  kthread+0x206/0x300
[  191.244352]  ? process_one_work+0xe20/0xe20
[  191.248587]  ? kthread_stop+0x570/0x570
[  191.252459]  ret_from_fork+0x3a/0x50
[  191.256082] Code: 14 3e ff 8b 4b 78 55 4d 89 f9 41 56 41 55 48 c7 c7 a0 cf db 82 41 54 44 8b 44 24 2c 48 8b 54 24 30 48 8b 74 24 20 e8 16 94 13 ff <0f> 0b 48 c7 c7 60 8e 1f 85 48 83 c4 20 e8 55 ef a6 ff 89 74 24
[  191.275327] RIP: skb_panic+0xc3/0x100 RSP: ffff8801d54072f0
[  191.281024] ---[ end trace 7ea51094e099e006 ]---
[  191.285724] Kernel panic - not syncing: Fatal exception in interrupt
[  191.292168] Kernel Offset: disabled
[  191.295697] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---

Reproducer:

	ip link add h1 type veth peer name swp1
	ip link add h3 type veth peer name swp3

	ip link set dev h1 up
	ip address add 192.0.2.1/28 dev h1

	ip link add dev vh3 type vrf table 20
	ip link set dev h3 master vh3
	ip link set dev vh3 up
	ip link set dev h3 up

	ip link set dev swp3 up
	ip address add dev swp3 2001:db8:2::1/64

	ip link set dev swp1 up
	tc qdisc add dev swp1 clsact

	ip link add name gt6 type ip6erspan \
		local 2001:db8:2::1 remote 2001:db8:2::2 oseq okey 123
	ip link set dev gt6 up

	sleep 1

	tc filter add dev swp1 ingress pref 1000 matchall skip_hw \
		action mirred egress mirror dev gt6
	ping -I h1 192.0.2.2

Fixes: e41c7c68 ("ip6erspan: make sure enough headroom at xmit.")
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Acked-by: NWilliam Tu <u9012063@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

__gre6_xmit() pushes GRE headers before handing over to ip6_tnl_xmit()
for generic IP-in-IP processing. However it doesn't make sure that there
is enough headroom to push the header to. That can lead to the panic
cited below. (Reproducer below that).

Fix by requesting either needed_headroom if already primed, or just the
bare minimum needed for the header otherwise.

[  158.576725] kernel BUG at net/core/skbuff.c:104!
[  158.581510] invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
[  158.587174] Modules linked in: act_mirred cls_matchall ip6_gre ip6_tunnel tunnel6 gre sch_ingress vrf veth x86_pkg_temp_thermal mlx_platform nfsd e1000e leds_mlxcpld
[  158.602268] CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 4.17.0-rc4-net_master-custom-139 #10
[  158.610938] Hardware name: Mellanox Technologies Ltd. "MSN2410-CB2F"/"SA000874", BIOS 4.6.5 03/08/2016
[  158.620426] RIP: 0010:skb_panic+0xc3/0x100
[  158.624586] RSP: 0018:ffff8801d3f27110 EFLAGS: 00010286
[  158.629882] RAX: 0000000000000082 RBX: ffff8801c02cc040 RCX: 0000000000000000
[  158.637127] RDX: 0000000000000082 RSI: dffffc0000000000 RDI: ffffed003a7e4e18
[  158.644366] RBP: ffff8801bfec8020 R08: ffffed003aabce19 R09: ffffed003aabce19
[  158.651574] R10: 000000000000000b R11: ffffed003aabce18 R12: ffff8801c364de66
[  158.658786] R13: 000000000000002c R14: 00000000000000c0 R15: ffff8801c364de68
[  158.666007] FS:  0000000000000000(0000) GS:ffff8801d5400000(0000) knlGS:0000000000000000
[  158.674212] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  158.680036] CR2: 00007f4b3702dcd0 CR3: 0000000003228002 CR4: 00000000001606e0
[  158.687228] Call Trace:
[  158.689752]  ? __gre6_xmit+0x246/0xd80 [ip6_gre]
[  158.694475]  ? __gre6_xmit+0x246/0xd80 [ip6_gre]
[  158.699141]  skb_push+0x78/0x90
[  158.702344]  __gre6_xmit+0x246/0xd80 [ip6_gre]
[  158.706872]  ip6gre_tunnel_xmit+0x3bc/0x610 [ip6_gre]
[  158.711992]  ? __gre6_xmit+0xd80/0xd80 [ip6_gre]
[  158.716668]  ? debug_check_no_locks_freed+0x210/0x210
[  158.721761]  ? print_irqtrace_events+0x120/0x120
[  158.726461]  ? sched_clock_cpu+0x18/0x210
[  158.730572]  ? sched_clock_cpu+0x18/0x210
[  158.734692]  ? cyc2ns_read_end+0x10/0x10
[  158.738705]  ? skb_network_protocol+0x76/0x200
[  158.743216]  ? netif_skb_features+0x1b2/0x550
[  158.747648]  dev_hard_start_xmit+0x137/0x770
[  158.752010]  sch_direct_xmit+0x2ef/0x5d0
[  158.755992]  ? pfifo_fast_dequeue+0x3fa/0x670
[  158.760460]  ? pfifo_fast_change_tx_queue_len+0x810/0x810
[  158.765975]  ? __lock_is_held+0xa0/0x160
[  158.770002]  __qdisc_run+0x39e/0xfc0
[  158.773673]  ? _raw_spin_unlock+0x29/0x40
[  158.777781]  ? pfifo_fast_enqueue+0x24b/0x3e0
[  158.782191]  ? sch_direct_xmit+0x5d0/0x5d0
[  158.786372]  ? pfifo_fast_dequeue+0x670/0x670
[  158.790818]  ? __dev_queue_xmit+0x172/0x1770
[  158.795195]  ? preempt_count_sub+0xf/0xd0
[  158.799313]  __dev_queue_xmit+0x410/0x1770
[  158.803512]  ? ___slab_alloc+0x605/0x930
[  158.807525]  ? ___slab_alloc+0x605/0x930
[  158.811540]  ? memcpy+0x34/0x50
[  158.814768]  ? netdev_pick_tx+0x1c0/0x1c0
[  158.818895]  ? __skb_clone+0x2fd/0x3d0
[  158.822712]  ? __copy_skb_header+0x270/0x270
[  158.827079]  ? rcu_read_lock_sched_held+0x93/0xa0
[  158.831903]  ? kmem_cache_alloc+0x344/0x4d0
[  158.836199]  ? skb_clone+0x123/0x230
[  158.839869]  ? skb_split+0x820/0x820
[  158.843521]  ? tcf_mirred+0x554/0x930 [act_mirred]
[  158.848407]  tcf_mirred+0x554/0x930 [act_mirred]
[  158.853104]  ? tcf_mirred_act_wants_ingress.part.2+0x10/0x10 [act_mirred]
[  158.860005]  ? __lock_acquire+0x706/0x26e0
[  158.864162]  ? mark_lock+0x13d/0xb40
[  158.867832]  tcf_action_exec+0xcf/0x2a0
[  158.871736]  tcf_classify+0xfa/0x340
[  158.875402]  __netif_receive_skb_core+0x8e1/0x1c60
[  158.880334]  ? nf_ingress+0x500/0x500
[  158.884059]  ? process_backlog+0x347/0x4b0
[  158.888241]  ? lock_acquire+0xd8/0x320
[  158.892050]  ? process_backlog+0x1b6/0x4b0
[  158.896228]  ? process_backlog+0xc2/0x4b0
[  158.900291]  process_backlog+0xc2/0x4b0
[  158.904210]  net_rx_action+0x5cc/0x980
[  158.908047]  ? napi_complete_done+0x2c0/0x2c0
[  158.912525]  ? rcu_read_unlock+0x80/0x80
[  158.916534]  ? __lock_is_held+0x34/0x160
[  158.920541]  __do_softirq+0x1d4/0x9d2
[  158.924308]  ? trace_event_raw_event_irq_handler_exit+0x140/0x140
[  158.930515]  run_ksoftirqd+0x1d/0x40
[  158.934152]  smpboot_thread_fn+0x32b/0x690
[  158.938299]  ? sort_range+0x20/0x20
[  158.941842]  ? preempt_count_sub+0xf/0xd0
[  158.945940]  ? schedule+0x5b/0x140
[  158.949412]  kthread+0x206/0x300
[  158.952689]  ? sort_range+0x20/0x20
[  158.956249]  ? kthread_stop+0x570/0x570
[  158.960164]  ret_from_fork+0x3a/0x50
[  158.963823] Code: 14 3e ff 8b 4b 78 55 4d 89 f9 41 56 41 55 48 c7 c7 a0 cf db 82 41 54 44 8b 44 24 2c 48 8b 54 24 30 48 8b 74 24 20 e8 16 94 13 ff <0f> 0b 48 c7 c7 60 8e 1f 85 48 83 c4 20 e8 55 ef a6 ff 89 74 24
[  158.983235] RIP: skb_panic+0xc3/0x100 RSP: ffff8801d3f27110
[  158.988935] ---[ end trace 5af56ee845aa6cc8 ]---
[  158.993641] Kernel panic - not syncing: Fatal exception in interrupt
[  159.000176] Kernel Offset: disabled
[  159.003767] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---

Reproducer:

	ip link add h1 type veth peer name swp1
	ip link add h3 type veth peer name swp3

	ip link set dev h1 up
	ip address add 192.0.2.1/28 dev h1

	ip link add dev vh3 type vrf table 20
	ip link set dev h3 master vh3
	ip link set dev vh3 up
	ip link set dev h3 up

	ip link set dev swp3 up
	ip address add dev swp3 2001:db8:2::1/64

	ip link set dev swp1 up
	tc qdisc add dev swp1 clsact

	ip link add name gt6 type ip6gretap \
		local 2001:db8:2::1 remote 2001:db8:2::2
	ip link set dev gt6 up

	sleep 1

	tc filter add dev swp1 ingress pref 1000 matchall skip_hw \
		action mirred egress mirror dev gt6
	ping -I h1 192.0.2.2

Fixes: c12b395a ("gre: Support GRE over IPv6")
Signed-off-by: NPetr Machata <petrm@mellanox.com>
Acked-by: NWilliam Tu <u9012063@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ERSPAN only support version 1 and 2.  When packets send to an
erspan device which does not have proper version number set,
drop the packet.  In real case, we observe multicast packets
sent to the erspan pernet device, erspan0, which does not have
erspan version configured.
Reported-by: NGreg Rose <gvrose8192@gmail.com>
Signed-off-by: NWilliam Tu <u9012063@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently the truncated bit is set only when 1) the mirrored packet
is larger than mtu and 2) the ipv4 packet tot_len is larger than
the actual skb->len.  This patch adds another case for detecting
whether ipv6 packet is truncated or not, by checking the ipv6 header
payload_len and the skb->len.
Reported-by: NXiaoyan Jin <xiaoyanj@vmware.com>
Signed-off-by: NWilliam Tu <u9012063@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add stubs to retrieve a handle to an IPv6 FIB table, fib6_get_table,
a stub to do a lookup in a specific table, fib6_table_lookup, and
a stub for a full route lookup.

The stubs are needed for core bpf code to handle the case when the
IPv6 module is not builtin.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Similar to IPv4, IPv6 should use the FIB lookup result in the
tracepoint.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Add IPv6 equivalent to fib_lookup. Does a fib lookup, including rules,
but returns a FIB entry, fib6_info, rather than a dst based rt6_info.
fib6_lookup is any where from 140% (MULTIPLE_TABLES config disabled)
to 60% faster than any of the dst based lookup methods (without custom
rules) and 25% faster with custom rules (e.g., l3mdev rule).

Since the lookup function has a completely different signature,
fib6_rule_action is split into 2 paths: the existing one is
renamed __fib6_rule_action and a new one for the fib6_info path
is added. fib6_rule_action decides which to call based on the
lookup_ptr. If it is fib6_table_lookup then the new path is taken.

Caller must hold rcu lock as no reference is taken on the returned
fib entry.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Move source address lookup from fib6_rule_action to a helper. It will be
used in a later patch by a second variant for fib6_rule_action.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

ip6_pol_route is used for ingress and egress FIB lookups. Refactor it
moving the table lookup into a separate fib6_table_lookup that can be
invoked separately and export the new function.

ip6_pol_route now calls fib6_table_lookup and uses the result to generate
a dst based rt6_info.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Rename rt6_multipath_select to fib6_multipath_select and export it.
A later patch wants access to it similar to IPv4's fib_select_path.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Rename fib6_lookup to fib6_node_lookup to better reflect what it
returns. The fib6_lookup name will be used in a later patch for
an IPv6 equivalent to IPv4's fib_lookup.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

This version has some suggestions by Eric Dumazet:

- Use a local variable for the mark in IPv6 instead of ctl_sk to avoid SMP
races.
- Use the more elegant "IP4_REPLY_MARK(net, skb->mark) ?: sk->sk_mark"
statement.
- Factorize code as sk_fullsock() check is not necessary.

Aidan McGurn from Openwave Mobility systems reported the following bug:

"Marked routing is broken on customer deployment. Its effects are large
increase in Uplink retransmissions caused by the client never receiving
the final ACK to their FINACK - this ACK misses the mark and routes out
of the incorrect route."

Currently marks are added to sk_buffs for replies when the "fwmark_reflect"
sysctl is enabled. But not for TW sockets that had sk->sk_mark set via
setsockopt(SO_MARK..).

Fix this in IPv4/v6 by adding tw->tw_mark for TIME_WAIT sockets. Copy the the
original sk->sk_mark in __inet_twsk_hashdance() to the new tw->tw_mark location.
Then progate this so that the skb gets sent with the correct mark. Do the same
for resets. Give the "fwmark_reflect" sysctl precedence over sk->sk_mark so that
netfilter rules are still honored.
Signed-off-by: NJon Maxwell <jmaxwell37@gmail.com>
Reviewed-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

WARNING: lock held when returning to user space!
4.17.0-rc3+ #37 Not tainted

syz-executor1/27662 is leaving the kernel with locks still held!
1 lock held by syz-executor1/27662:
 #0: 00000000f661aee7 (rcu_read_lock){....}, at: ip6_route_del+0xea/0x13f0 net/ipv6/route.c:3206
BUG: scheduling while atomic: syz-executor1/27662/0x00000002
INFO: lockdep is turned off.
Modules linked in:
Kernel panic - not syncing: scheduling while atomic

CPU: 1 PID: 27662 Comm: syz-executor1 Not tainted 4.17.0-rc3+ #37
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 panic+0x22f/0x4de kernel/panic.c:184
 __schedule_bug.cold.85+0xdf/0xdf kernel/sched/core.c:3290
 schedule_debug kernel/sched/core.c:3307 [inline]
 __schedule+0x139e/0x1e30 kernel/sched/core.c:3412
 schedule+0xef/0x430 kernel/sched/core.c:3549
 exit_to_usermode_loop+0x220/0x310 arch/x86/entry/common.c:152
 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:265 [inline]
 do_syscall_64+0x6ac/0x800 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x455979
RSP: 002b:00007fbf4051dc68 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: 0000000000000000 RBX: 00007fbf4051e6d4 RCX: 0000000000455979
RDX: 00000000200001c0 RSI: 000000000000890c RDI: 0000000000000013
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000003c8 R14: 00000000006f9b60 R15: 0000000000000000
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..

Fixes: 23fb93a4 ("net/ipv6: Cleanup exception and cache route handling")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: David Ahern <dsahern@gmail.com>
Reported-by: Nsyzbot <syzkaller@googlegroups.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Damir reported a breakage of SO_BINDTODEVICE for UDP sockets.
In absence of VRF devices, after commit fb74c277 ("net:
ipv4: add second dif to udp socket lookups") the dif mismatch
isn't fatal anymore for UDP socket lookup with non null
sk_bound_dev_if, breaking SO_BINDTODEVICE semantics.

This changeset addresses the issue making the dif match mandatory
again in the above scenario.
Reported-by: NDamir Mansurov <dnman@oktetlabs.ru>
Fixes: fb74c277 ("net: ipv4: add second dif to udp socket lookups")
Fixes: 1801b570 ("net: ipv6: add second dif to udp socket lookups")
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

No changes in refcount semantics -- key init is false; replace

static_key_enable         with   static_branch_enable
static_key_slow_inc|dec   with   static_branch_inc|dec
static_key_false          with   static_branch_unlikely

Added a '_key' suffix to udp and udpv6 encap_needed, for better
self documentation.
Signed-off-by: NDavidlohr Bueso <dbueso@suse.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>