Commit Graph

44 Commits

Author SHA1 Message Date
Eric Dumazet
c0b98ac1cc ipv6: sr: block BH in seg6_output_core() and seg6_input_core()
As explained in commit 1378817486 ("tipc: block BH
before using dst_cache"), net/core/dst_cache.c
helpers need to be called with BH disabled.

Disabling preemption in seg6_output_core() is not good enough,
because seg6_output_core() is called from process context,
lwtunnel_output() only uses rcu_read_lock().

We might be interrupted by a softirq, re-enter seg6_output_core()
and corrupt dst_cache data structures.

Fix the race by using local_bh_disable() instead of
preempt_disable().

Apply a similar change in seg6_input_core().

Fixes: fa79581ea6 ("ipv6: sr: fix several BUGs when preemption is enabled")
Fixes: 6c8702c60b ("ipv6: sr: add support for SRH encapsulation and injection with lwtunnels")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: David Lebrun <dlebrun@google.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20240531132636.2637995-4-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-06-03 18:50:08 -07:00
Andrea Mayer
5447f9708d ipv6: sr: fix missing sk_buff release in seg6_input_core
The seg6_input() function is responsible for adding the SRH into a
packet, delegating the operation to the seg6_input_core(). This function
uses the skb_cow_head() to ensure that there is sufficient headroom in
the sk_buff for accommodating the link-layer header.
In the event that the skb_cow_header() function fails, the
seg6_input_core() catches the error but it does not release the sk_buff,
which will result in a memory leak.

This issue was introduced in commit af3b5158b8 ("ipv6: sr: fix BUG due
to headroom too small after SRH push") and persists even after commit
7a3f5b0de3 ("netfilter: add netfilter hooks to SRv6 data plane"),
where the entire seg6_input() code was refactored to deal with netfilter
hooks.

The proposed patch addresses the identified memory leak by requiring the
seg6_input_core() function to release the sk_buff in the event that
skb_cow_head() fails.

Fixes: af3b5158b8 ("ipv6: sr: fix BUG due to headroom too small after SRH push")
Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-05-20 11:36:34 +01:00
Yuya Tajima
fa0583c202 seg6: Cleanup duplicates of skb_dst_drop calls
In processing IPv6 segment routing header (SRH), several functions call
skb_dst_drop before ip6_route_input. However, ip6_route_input calls
skb_dst_drop within it, so there is no need to call skb_dst_drop in advance.

Signed-off-by: Yuya Tajima <yuya.tajimaa@gmail.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-17 09:05:47 +01:00
Andrea Mayer
13f0296be8 seg6: add support for SRv6 H.L2Encaps.Red behavior
The SRv6 H.L2Encaps.Red behavior described in [1] is an optimization of
the SRv6 H.L2Encaps behavior [2].

H.L2Encaps.Red reduces the length of the SRH by excluding the first
segment (SID) in the SRH of the pushed IPv6 header. The first SID is
only placed in the IPv6 Destination Address field of the pushed IPv6
header.
When the SRv6 Policy only contains one SID the SRH is omitted, unless
there is an HMAC TLV to be carried.

[1] - https://datatracker.ietf.org/doc/html/rfc8986#section-5.4
[2] - https://datatracker.ietf.org/doc/html/rfc8986#section-5.3

Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it>
Signed-off-by: Anton Makarov <anton.makarov11235@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-07-29 12:14:03 +01:00
Andrea Mayer
b07c8cdbe9 seg6: add support for SRv6 H.Encaps.Red behavior
The SRv6 H.Encaps.Red behavior described in [1] is an optimization of
the SRv6 H.Encaps behavior [2].

H.Encaps.Red reduces the length of the SRH by excluding the first
segment (SID) in the SRH of the pushed IPv6 header. The first SID is
only placed in the IPv6 Destination Address field of the pushed IPv6
header.
When the SRv6 Policy only contains one SID the SRH is omitted, unless
there is an HMAC TLV to be carried.

[1] - https://datatracker.ietf.org/doc/html/rfc8986#section-5.2
[2] - https://datatracker.ietf.org/doc/html/rfc8986#section-5.1

Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it>
Signed-off-by: Anton Makarov <anton.makarov11235@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-07-29 12:14:02 +01:00
Andrea Mayer
df8386d13e seg6: fix skb checksum evaluation in SRH encapsulation/insertion
Support for SRH encapsulation and insertion was introduced with
commit 6c8702c60b ("ipv6: sr: add support for SRH encapsulation and
injection with lwtunnels"), through the seg6_do_srh_encap() and
seg6_do_srh_inline() functions, respectively.
The former encapsulates the packet in an outer IPv6 header along with
the SRH, while the latter inserts the SRH between the IPv6 header and
the payload. Then, the headers are initialized/updated according to the
operating mode (i.e., encap/inline).
Finally, the skb checksum is calculated to reflect the changes applied
to the headers.

The IPv6 payload length ('payload_len') is not initialized
within seg6_do_srh_{inline,encap}() but is deferred in seg6_do_srh(), i.e.
the caller of seg6_do_srh_{inline,encap}().
However, this operation invalidates the skb checksum, since the
'payload_len' is updated only after the checksum is evaluated.

To solve this issue, the initialization of the IPv6 payload length is
moved from seg6_do_srh() directly into the seg6_do_srh_{inline,encap}()
functions and before the skb checksum update takes place.

Fixes: 6c8702c60b ("ipv6: sr: add support for SRH encapsulation and injection with lwtunnels")
Reported-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/all/20220705190727.69d532417be7438b15404ee1@uniroma2.it
Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-07-14 10:15:15 +02:00
Andrea Mayer
ae68d93354 seg6: fix the iif in the IPv6 socket control block
When an IPv4 packet is received, the ip_rcv_core(...) sets the receiving
interface index into the IPv4 socket control block (v5.16-rc4,
net/ipv4/ip_input.c line 510):

    IPCB(skb)->iif = skb->skb_iif;

If that IPv4 packet is meant to be encapsulated in an outer IPv6+SRH
header, the seg6_do_srh_encap(...) performs the required encapsulation.
In this case, the seg6_do_srh_encap function clears the IPv6 socket control
block (v5.16-rc4 net/ipv6/seg6_iptunnel.c line 163):

    memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));

The memset(...) was introduced in commit ef489749aa ("ipv6: sr: clear
IP6CB(skb) on SRH ip4ip6 encapsulation") a long time ago (2019-01-29).

Since the IPv6 socket control block and the IPv4 socket control block share
the same memory area (skb->cb), the receiving interface index info is lost
(IP6CB(skb)->iif is set to zero).

As a side effect, that condition triggers a NULL pointer dereference if
commit 0857d6f8c7 ("ipv6: When forwarding count rx stats on the orig
netdev") is applied.

To fix that issue, we set the IP6CB(skb)->iif with the index of the
receiving interface once again.

Fixes: ef489749aa ("ipv6: sr: clear IP6CB(skb) on SRH ip4ip6 encapsulation")
Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20211208195409.12169-1-andrea.mayer@uniroma2.it
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-09 07:55:42 -08:00
Colin Ian King
bf0df73a2f seg6_iptunnel: Remove redundant initialization of variable err
The variable err is being initialized with a value that is never read, it
is being updated later on. The assignment is redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-03 12:32:25 +01:00
Lv Ruyi
53c622db99 ipv6: remove duplicated 'net/lwtunnel.h' include
Remove all but the first include of net/lwtunnel.h from seg6_iptunnel.c.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Lv Ruyi <lv.ruyi@zte.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-31 12:09:23 +01:00
Ryoga Saito
7a3f5b0de3 netfilter: add netfilter hooks to SRv6 data plane
This patch introduces netfilter hooks for solving the problem that
conntrack couldn't record both inner flows and outer flows.

This patch also introduces a new sysctl toggle for enabling lightweight
tunnel netfilter hooks.

Signed-off-by: Ryoga Saito <contact@proelbtn.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-08-30 01:51:36 +02:00
Ioana-Ruxandra Stăncioi
88fab21c69 seg6_iptunnel: Refactor seg6_lwt_headroom out of uapi header
Refactor the function seg6_lwt_headroom out of the seg6_iptunnel.h uapi
header, because it is only used in seg6_iptunnel.c. Moreover, it is only
used in the kernel code, as indicated by the "#ifdef __KERNEL__".

Suggested-by: David Miller <davem@davemloft.net>
Signed-off-by: Ioana-Ruxandra Stăncioi <stancioi@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-03 17:57:40 -07:00
Ahmed Abdelsalam
bb986a5042 seg6: fix seg6_validate_srh() to avoid slab-out-of-bounds
The seg6_validate_srh() is used to validate SRH for three cases:

case1: SRH of data-plane SRv6 packets to be processed by the Linux kernel.
Case2: SRH of the netlink message received  from user-space (iproute2)
Case3: SRH injected into packets through setsockopt

In case1, the SRH can be encoded in the Reduced way (i.e., first SID is
carried in DA only and not represented as SID in the SRH) and the
seg6_validate_srh() now handles this case correctly.

In case2 and case3, the SRH shouldn’t be encoded in the Reduced way
otherwise we lose the first segment (i.e., the first hop).

The current implementation of the seg6_validate_srh() allow SRH of case2
and case3 to be encoded in the Reduced way. This leads a slab-out-of-bounds
problem.

This patch verifies SRH of case1, case2 and case3. Allowing case1 to be
reduced while preventing SRH of case2 and case3 from being reduced .

Reported-by: syzbot+e8c028b62439eac42073@syzkaller.appspotmail.com
Reported-by: YueHaibing <yuehaibing@huawei.com>
Fixes: 0cb7498f23 ("seg6: fix SRH processing to comply with RFC8754")
Signed-off-by: Ahmed Abdelsalam <ahabdels@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-04 15:39:32 -07:00
Alexander Aring
faee676944 net: add net available in build_state
The build_state callback of lwtunnel doesn't contain the net namespace
structure yet. This patch will add it so we can check on specific
address configuration at creation time of rpl source routes.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-29 22:30:57 -07:00
David S. Miller
1d34357931 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Minor overlapping changes, nothing serious.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-12 22:34:48 -07:00
Paolo Lungaroni
2677625387 seg6: fix SRv6 L2 tunnels to use IANA-assigned protocol number
The Internet Assigned Numbers Authority (IANA) has recently assigned
a protocol number value of 143 for Ethernet [1].

Before this assignment, encapsulation mechanisms such as Segment Routing
used the IPv6-NoNxt protocol number (59) to indicate that the encapsulated
payload is an Ethernet frame.

In this patch, we add the definition of the Ethernet protocol number to the
kernel headers and update the SRv6 L2 tunnels to use it.

[1] https://www.iana.org/assignments/protocol-numbers/protocol-numbers.xhtml

Signed-off-by: Paolo Lungaroni <paolo.lungaroni@cnit.it>
Reviewed-by: Andrea Mayer <andrea.mayer@uniroma2.it>
Acked-by: Ahmed Abdelsalam <ahmed.abdelsalam@gssi.it>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-11 23:49:30 -07:00
Gustavo A. R. Silva
b0c9a2d9a8 ipv6: Replace zero-length array with flexible-array member
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-28 12:08:37 -08:00
Thomas Gleixner
2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00
Johannes Berg
8cb081746c netlink: make validation more configurable for future strictness
We currently have two levels of strict validation:

 1) liberal (default)
     - undefined (type >= max) & NLA_UNSPEC attributes accepted
     - attribute length >= expected accepted
     - garbage at end of message accepted
 2) strict (opt-in)
     - NLA_UNSPEC attributes accepted
     - attribute length >= expected accepted

Split out parsing strictness into four different options:
 * TRAILING     - check that there's no trailing data after parsing
                  attributes (in message or nested)
 * MAXTYPE      - reject attrs > max known type
 * UNSPEC       - reject attributes with NLA_UNSPEC policy entries
 * STRICT_ATTRS - strictly validate attribute size

The default for future things should be *everything*.
The current *_strict() is a combination of TRAILING and MAXTYPE,
and is renamed to _deprecated_strict().
The current regular parsing has none of this, and is renamed to
*_parse_deprecated().

Additionally it allows us to selectively set one of the new flags
even on old policies. Notably, the UNSPEC flag could be useful in
this case, since it can be arranged (by filling in the policy) to
not be an incompatible userspace ABI change, but would then going
forward prevent forgetting attribute entries. Similar can apply
to the POLICY flag.

We end up with the following renames:
 * nla_parse           -> nla_parse_deprecated
 * nla_parse_strict    -> nla_parse_deprecated_strict
 * nlmsg_parse         -> nlmsg_parse_deprecated
 * nlmsg_parse_strict  -> nlmsg_parse_deprecated_strict
 * nla_parse_nested    -> nla_parse_nested_deprecated
 * nla_validate_nested -> nla_validate_nested_deprecated

Using spatch, of course:
    @@
    expression TB, MAX, HEAD, LEN, POL, EXT;
    @@
    -nla_parse(TB, MAX, HEAD, LEN, POL, EXT)
    +nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT)

    @@
    expression NLH, HDRLEN, TB, MAX, POL, EXT;
    @@
    -nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT)
    +nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT)

    @@
    expression NLH, HDRLEN, TB, MAX, POL, EXT;
    @@
    -nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT)
    +nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT)

    @@
    expression TB, MAX, NLA, POL, EXT;
    @@
    -nla_parse_nested(TB, MAX, NLA, POL, EXT)
    +nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT)

    @@
    expression START, MAX, POL, EXT;
    @@
    -nla_validate_nested(START, MAX, POL, EXT)
    +nla_validate_nested_deprecated(START, MAX, POL, EXT)

    @@
    expression NLH, HDRLEN, MAX, POL, EXT;
    @@
    -nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT)
    +nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT)

For this patch, don't actually add the strict, non-renamed versions
yet so that it breaks compile if I get it wrong.

Also, while at it, make nla_validate and nla_parse go down to a
common __nla_validate_parse() function to avoid code duplication.

Ultimately, this allows us to have very strict validation for every
new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the
next patch, while existing things will continue to work as is.

In effect then, this adds fully strict validation for any new command.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-27 17:07:21 -04:00
Yohei Kanemaru
ef489749aa ipv6: sr: clear IP6CB(skb) on SRH ip4ip6 encapsulation
skb->cb may contain data from previous layers (in an observed case
IPv4 with L3 Master Device). In the observed scenario, the data in
IPCB(skb)->frags was misinterpreted as IP6CB(skb)->frag_max_size,
eventually caused an unexpected IPv6 fragmentation in ip6_fragment()
through ip6_finish_output().

This patch clears IP6CB(skb), which potentially contains garbage data,
on the SRH ip4ip6 encapsulation.

Fixes: 32d99d0b67 ("ipv6: sr: add support for ip4ip6 encapsulation")
Signed-off-by: Yohei Kanemaru <yohei.kanemaru@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-01-30 14:06:12 -08:00
Shmulik Ladkani
1b4e5ad5d6 ipv6: sr: properly initialize flowi6 prior passing to ip6_route_output
In 'seg6_output', stack variable 'struct flowi6 fl6' was missing
initialization.

Fixes: 6c8702c60b ("ipv6: sr: add support for SRH encapsulation and injection with lwtunnels")
Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-07 12:22:39 -08:00
Colin Ian King
3ee593adbb ipv6: sr: fix useless rol32 call on hash
The rol32 call is currently rotating hash but the rol'd value is
being discarded. I believe the current code is incorrect and hash
should be assigned the rotated value returned from rol32.

Detected by CoverityScan, CID#1468411 ("Useless call")

Fixes: b5facfdba1 ("ipv6: sr: Compute flowlabel for outer IPv6 header of seg6 encap mode")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: dlebrun@google.com
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-18 15:10:47 -07:00
David S. Miller
9c54aeb03a Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Filling in the padding slot in the bpf structure as a bug fix in 'ne'
overlapped with actually using that padding area for something in
'net-next'.

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-03 09:31:58 -04:00
Mathieu Xhonneux
bbb40a0b75 ipv6: sr: fix memory OOB access in seg6_do_srh_encap/inline
seg6_do_srh_encap and seg6_do_srh_inline can possibly do an
out-of-bounds access when adding the SRH to the packet. This no longer
happen when expanding the skb not only by the size of the SRH (+
outer IPv6 header), but also by skb->mac_len.

[   53.793056] BUG: KASAN: use-after-free in seg6_do_srh_encap+0x284/0x620
[   53.794564] Write of size 14 at addr ffff88011975ecfa by task ping/674

[   53.796665] CPU: 0 PID: 674 Comm: ping Not tainted 4.17.0-rc3-ARCH+ #90
[   53.796670] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS 1.11.0-20171110_100015-anatol 04/01/2014
[   53.796673] Call Trace:
[   53.796679]  <IRQ>
[   53.796689]  dump_stack+0x71/0xab
[   53.796700]  print_address_description+0x6a/0x270
[   53.796707]  kasan_report+0x258/0x380
[   53.796715]  ? seg6_do_srh_encap+0x284/0x620
[   53.796722]  memmove+0x34/0x50
[   53.796730]  seg6_do_srh_encap+0x284/0x620
[   53.796741]  ? seg6_do_srh+0x29b/0x360
[   53.796747]  seg6_do_srh+0x29b/0x360
[   53.796756]  seg6_input+0x2e/0x2e0
[   53.796765]  lwtunnel_input+0x93/0xd0
[   53.796774]  ipv6_rcv+0x690/0x920
[   53.796783]  ? ip6_input+0x170/0x170
[   53.796791]  ? eth_gro_receive+0x2d0/0x2d0
[   53.796800]  ? ip6_input+0x170/0x170
[   53.796809]  __netif_receive_skb_core+0xcc0/0x13f0
[   53.796820]  ? netdev_info+0x110/0x110
[   53.796827]  ? napi_complete_done+0xb6/0x170
[   53.796834]  ? e1000_clean+0x6da/0xf70
[   53.796845]  ? process_backlog+0x129/0x2a0
[   53.796853]  process_backlog+0x129/0x2a0
[   53.796862]  net_rx_action+0x211/0x5c0
[   53.796870]  ? napi_complete_done+0x170/0x170
[   53.796887]  ? run_rebalance_domains+0x11f/0x150
[   53.796891]  __do_softirq+0x10e/0x39e
[   53.796894]  do_softirq_own_stack+0x2a/0x40
[   53.796895]  </IRQ>
[   53.796898]  do_softirq.part.16+0x54/0x60
[   53.796900]  __local_bh_enable_ip+0x5b/0x60
[   53.796903]  ip6_finish_output2+0x416/0x9f0
[   53.796906]  ? ip6_dst_lookup_flow+0x110/0x110
[   53.796909]  ? ip6_sk_dst_lookup_flow+0x390/0x390
[   53.796911]  ? __rcu_read_unlock+0x66/0x80
[   53.796913]  ? ip6_mtu+0x44/0xf0
[   53.796916]  ? ip6_output+0xfc/0x220
[   53.796918]  ip6_output+0xfc/0x220
[   53.796921]  ? ip6_finish_output+0x2b0/0x2b0
[   53.796923]  ? memcpy+0x34/0x50
[   53.796926]  ip6_send_skb+0x43/0xc0
[   53.796929]  rawv6_sendmsg+0x1216/0x1530
[   53.796932]  ? __orc_find+0x6b/0xc0
[   53.796934]  ? rawv6_rcv_skb+0x160/0x160
[   53.796937]  ? __rcu_read_unlock+0x66/0x80
[   53.796939]  ? __rcu_read_unlock+0x66/0x80
[   53.796942]  ? is_bpf_text_address+0x1e/0x30
[   53.796944]  ? kernel_text_address+0xec/0x100
[   53.796946]  ? __kernel_text_address+0xe/0x30
[   53.796948]  ? unwind_get_return_address+0x2f/0x50
[   53.796950]  ? __save_stack_trace+0x92/0x100
[   53.796954]  ? save_stack+0x89/0xb0
[   53.796956]  ? kasan_kmalloc+0xa0/0xd0
[   53.796958]  ? kmem_cache_alloc+0xd2/0x1f0
[   53.796961]  ? prepare_creds+0x23/0x160
[   53.796963]  ? __x64_sys_capset+0x252/0x3e0
[   53.796966]  ? do_syscall_64+0x69/0x160
[   53.796968]  ? entry_SYSCALL_64_after_hwframe+0x44/0xa9
[   53.796971]  ? __alloc_pages_nodemask+0x170/0x380
[   53.796973]  ? __alloc_pages_slowpath+0x12c0/0x12c0
[   53.796977]  ? tty_vhangup+0x20/0x20
[   53.796979]  ? policy_nodemask+0x1a/0x90
[   53.796982]  ? __mod_node_page_state+0x8d/0xa0
[   53.796986]  ? __check_object_size+0xe7/0x240
[   53.796989]  ? __sys_sendto+0x229/0x290
[   53.796991]  ? rawv6_rcv_skb+0x160/0x160
[   53.796993]  __sys_sendto+0x229/0x290
[   53.796996]  ? __ia32_sys_getpeername+0x50/0x50
[   53.796999]  ? commit_creds+0x2de/0x520
[   53.797002]  ? security_capset+0x57/0x70
[   53.797004]  ? __x64_sys_capset+0x29f/0x3e0
[   53.797007]  ? __x64_sys_rt_sigsuspend+0xe0/0xe0
[   53.797011]  ? __do_page_fault+0x664/0x770
[   53.797014]  __x64_sys_sendto+0x74/0x90
[   53.797017]  do_syscall_64+0x69/0x160
[   53.797019]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[   53.797022] RIP: 0033:0x7f43b7a6714a
[   53.797023] RSP: 002b:00007ffd891bd368 EFLAGS: 00000246 ORIG_RAX:
000000000000002c
[   53.797026] RAX: ffffffffffffffda RBX: 00000000006129c0 RCX: 00007f43b7a6714a
[   53.797028] RDX: 0000000000000040 RSI: 00000000006129c0 RDI: 0000000000000004
[   53.797029] RBP: 00007ffd891be640 R08: 0000000000610940 R09: 000000000000001c
[   53.797030] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000040
[   53.797032] R13: 000000000060e6a0 R14: 0000000000008004 R15: 000000000040b661

[   53.797171] Allocated by task 642:
[   53.797460]  kasan_kmalloc+0xa0/0xd0
[   53.797463]  kmem_cache_alloc+0xd2/0x1f0
[   53.797465]  getname_flags+0x40/0x210
[   53.797467]  user_path_at_empty+0x1d/0x40
[   53.797469]  do_faccessat+0x12a/0x320
[   53.797471]  do_syscall_64+0x69/0x160
[   53.797473]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

[   53.797607] Freed by task 642:
[   53.797869]  __kasan_slab_free+0x130/0x180
[   53.797871]  kmem_cache_free+0xa8/0x230
[   53.797872]  filename_lookup+0x15b/0x230
[   53.797874]  do_faccessat+0x12a/0x320
[   53.797876]  do_syscall_64+0x69/0x160
[   53.797878]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

[   53.798014] The buggy address belongs to the object at ffff88011975e600
                which belongs to the cache names_cache of size 4096
[   53.799043] The buggy address is located 1786 bytes inside of
                4096-byte region [ffff88011975e600, ffff88011975f600)
[   53.800013] The buggy address belongs to the page:
[   53.800414] page:ffffea000465d600 count:1 mapcount:0
mapping:0000000000000000 index:0x0 compound_mapcount: 0
[   53.801259] flags: 0x17fff0000008100(slab|head)
[   53.801640] raw: 017fff0000008100 0000000000000000 0000000000000000
0000000100070007
[   53.803147] raw: dead000000000100 dead000000000200 ffff88011b185a40
0000000000000000
[   53.803787] page dumped because: kasan: bad access detected

[   53.804384] Memory state around the buggy address:
[   53.804788]  ffff88011975eb80: fb fb fb fb fb fb fb fb fb fb fb fb
fb fb fb fb
[   53.805384]  ffff88011975ec00: fb fb fb fb fb fb fb fb fb fb fb fb
fb fb fb fb
[   53.805979] >ffff88011975ec80: fb fb fb fb fb fb fb fb fb fb fb fb
fb fb fb fb
[   53.806577]                                                                 ^
[   53.807165]  ffff88011975ed00: fb fb fb fb fb fb fb fb fb fb fb fb
fb fb fb fb
[   53.807762]  ffff88011975ed80: fb fb fb fb fb fb fb fb fb fb fb fb
fb fb fb fb
[   53.808356] ==================================================================
[   53.808949] Disabling lock debugging due to kernel taint

Fixes: 6c8702c60b ("ipv6: sr: add support for SRH encapsulation and injection with lwtunnels")
Signed-off-by: David Lebrun <dlebrun@google.com>
Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-28 23:09:49 -04:00
Ahmed Abdelsalam
6df93462c2 ipv6: sr: extract the right key values for "seg6_make_flowlabel"
The seg6_make_flowlabel() is used by seg6_do_srh_encap() to compute the
flowlabel from a given skb. It relies on skb_get_hash() which eventually
calls __skb_flow_dissect() to extract the flow_keys struct values from
the skb.

In case of IPv4 traffic, calling seg6_make_flowlabel() after skb_push(),
skb_reset_network_header(), and skb_mac_header_rebuild() will results in
flow_keys struct of all key values set to zero.

This patch calls seg6_make_flowlabel() before resetting the headers of skb
to get the right key values.

Extracted Key values are based on the type inner packet as follows:
1) IPv6 traffic: src_IP, dst_IP, L4 proto, and flowlabel of inner packet.
2) IPv4 traffic: src_IP, dst_IP, L4 proto, src_port, and dst_port
3) L2 traffic: depends on what kind of traffic carried into the L2
frame. IPv6 and IPv4 traffic works as discussed 1) and 2)

Here a hex_dump of struct flow_keys for IPv4 and IPv6 traffic
10.100.1.100: 47302 > 30.0.0.2: 5001
00000000: 14 00 02 00 00 00 00 00 08 00 11 00 00 00 00 00
00000010: 00 00 00 00 00 00 00 00 13 89 b8 c6 1e 00 00 02
00000020: 0a 64 01 64

fc00:a1:a > b2::2
00000000: 28 00 03 00 00 00 00 00 86 dd 11 00 99 f9 02 00
00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 b2 00 00
00000020: 00 00 00 00 00 00 00 00 00 00 00 02 fc 00 00 a1
00000030: 00 00 00 00 00 00 00 00 00 00 00 0a

Signed-off-by: Ahmed Abdelsalam <amsalam20@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-30 12:13:43 -04:00
Ahmed Abdelsalam
b5facfdba1 ipv6: sr: Compute flowlabel for outer IPv6 header of seg6 encap mode
ECMP (equal-cost multipath) hashes are typically computed on the packets'
5-tuple(src IP, dst IP, src port, dst port, L4 proto).

For encapsulated packets, the L4 data is not readily available and ECMP
hashing will often revert to (src IP, dst IP). This will lead to traffic
polarization on a single ECMP path, causing congestion and waste of network
capacity.

In IPv6, the 20-bit flow label field is also used as part of the ECMP hash.
In the lack of L4 data, the hashing will be on (src IP, dst IP, flow
label). Having a non-zero flow label is thus important for proper traffic
load balancing when L4 data is unavailable (i.e., when packets are
encapsulated).

Currently, the seg6_do_srh_encap() function extracts the original packet's
flow label and set it as the outer IPv6 flow label. There are two issues
with this behaviour:

a) There is no guarantee that the inner flow label is set by the source.
b) If the original packet is not IPv6, the flow label will be set to
zero (e.g., IPv4 or L2 encap).

This patch adds a function, named seg6_make_flowlabel(), that computes a
flow label from a given skb. It supports IPv6, IPv4 and L2 payloads, and
leverages the per namespace 'seg6_flowlabel" sysctl value.

The currently support behaviours are as follows:
-1 set flowlabel to zero.
0 copy flowlabel from Inner paceket in case of Inner IPv6
(Set flowlabel to 0 in case IPv4/L2)
1 Compute the flowlabel using seg6_make_flowlabel()

This patch has been tested for IPv6, IPv4, and L2 traffic.

Signed-off-by: Ahmed Abdelsalam <amsalam20@gmail.com>
Acked-by: David Lebrun <dlebrun@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-25 13:02:15 -04:00
Ahmed Abdelsalam
a957fa190a ipv6: sr: fix NULL pointer dereference in seg6_do_srh_encap()- v4 pkts
In case of seg6 in encap mode, seg6_do_srh_encap() calls set_tun_src()
in order to set the src addr of outer IPv6 header.

The net_device is required for set_tun_src(). However calling ip6_dst_idev()
on dst_entry in case of IPv4 traffic results on the following bug.

Using just dst->dev should fix this BUG.

[  196.242461] BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
[  196.242975] PGD 800000010f076067 P4D 800000010f076067 PUD 10f060067 PMD 0
[  196.243329] Oops: 0000 [#1] SMP PTI
[  196.243468] Modules linked in: nfsd auth_rpcgss nfs_acl nfs lockd grace fscache sunrpc crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc aesni_intel aes_x86_64 crypto_simd cryptd input_leds glue_helper led_class pcspkr serio_raw mac_hid video autofs4 hid_generic usbhid hid e1000 i2c_piix4 ahci pata_acpi libahci
[  196.244362] CPU: 2 PID: 1089 Comm: ping Not tainted 4.16.0+ #1
[  196.244606] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[  196.244968] RIP: 0010:seg6_do_srh_encap+0x1ac/0x300
[  196.245236] RSP: 0018:ffffb2ce00b23a60 EFLAGS: 00010202
[  196.245464] RAX: 0000000000000000 RBX: ffff8c7f53eea300 RCX: 0000000000000000
[  196.245742] RDX: 0000f10000000000 RSI: ffff8c7f52085a6c RDI: ffff8c7f41166850
[  196.246018] RBP: ffffb2ce00b23aa8 R08: 00000000000261e0 R09: ffff8c7f41166800
[  196.246294] R10: ffffdce5040ac780 R11: ffff8c7f41166828 R12: ffff8c7f41166808
[  196.246570] R13: ffff8c7f52085a44 R14: ffffffffb73211c0 R15: ffff8c7e69e44200
[  196.246846] FS:  00007fc448789700(0000) GS:ffff8c7f59d00000(0000) knlGS:0000000000000000
[  196.247286] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  196.247526] CR2: 0000000000000000 CR3: 000000010f05a000 CR4: 00000000000406e0
[  196.247804] Call Trace:
[  196.247972]  seg6_do_srh+0x15b/0x1c0
[  196.248156]  seg6_output+0x3c/0x220
[  196.248341]  ? prandom_u32+0x14/0x20
[  196.248526]  ? ip_idents_reserve+0x6c/0x80
[  196.248723]  ? __ip_select_ident+0x90/0x100
[  196.248923]  ? ip_append_data.part.50+0x6c/0xd0
[  196.249133]  lwtunnel_output+0x44/0x70
[  196.249328]  ip_send_skb+0x15/0x40
[  196.249515]  raw_sendmsg+0x8c3/0xac0
[  196.249701]  ? _copy_from_user+0x2e/0x60
[  196.249897]  ? rw_copy_check_uvector+0x53/0x110
[  196.250106]  ? _copy_from_user+0x2e/0x60
[  196.250299]  ? copy_msghdr_from_user+0xce/0x140
[  196.250508]  sock_sendmsg+0x36/0x40
[  196.250690]  ___sys_sendmsg+0x292/0x2a0
[  196.250881]  ? _cond_resched+0x15/0x30
[  196.251074]  ? copy_termios+0x1e/0x70
[  196.251261]  ? _copy_to_user+0x22/0x30
[  196.251575]  ? tty_mode_ioctl+0x1c3/0x4e0
[  196.251782]  ? _cond_resched+0x15/0x30
[  196.251972]  ? mutex_lock+0xe/0x30
[  196.252152]  ? vvar_fault+0xd2/0x110
[  196.252337]  ? __do_fault+0x1f/0xc0
[  196.252521]  ? __handle_mm_fault+0xc1f/0x12d0
[  196.252727]  ? __sys_sendmsg+0x63/0xa0
[  196.252919]  __sys_sendmsg+0x63/0xa0
[  196.253107]  do_syscall_64+0x72/0x200
[  196.253305]  entry_SYSCALL_64_after_hwframe+0x3d/0xa2
[  196.253530] RIP: 0033:0x7fc4480b0690
[  196.253715] RSP: 002b:00007ffde9f252f8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[  196.254053] RAX: ffffffffffffffda RBX: 0000000000000040 RCX: 00007fc4480b0690
[  196.254331] RDX: 0000000000000000 RSI: 000000000060a360 RDI: 0000000000000003
[  196.254608] RBP: 00007ffde9f253f0 R08: 00000000002d1e81 R09: 0000000000000002
[  196.254884] R10: 00007ffde9f250c0 R11: 0000000000000246 R12: 0000000000b22070
[  196.255205] R13: 20c49ba5e353f7cf R14: 431bde82d7b634db R15: 00007ffde9f278fe
[  196.255484] Code: a5 0f b6 45 c0 41 88 41 28 41 0f b6 41 2c 48 c1 e0 04 49 8b 54 01 38 49 8b 44 01 30 49 89 51 20 49 89 41 18 48 8b 83 b0 00 00 00 <48> 8b 30 49 8b 86 08 0b 00 00 48 8b 40 20 48 8b 50 08 48 0b 10
[  196.256190] RIP: seg6_do_srh_encap+0x1ac/0x300 RSP: ffffb2ce00b23a60
[  196.256445] CR2: 0000000000000000
[  196.256676] ---[ end trace 71af7d093603885c ]---

Fixes: 8936ef7604 ("ipv6: sr: fix NULL pointer dereference when setting encap source address")
Signed-off-by: Ahmed Abdelsalam <amsalam20@gmail.com>
Acked-by: David Lebrun <dlebrun@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-22 21:04:17 -04:00
David Lebrun
5807b22c91 ipv6: sr: fix seg6 encap performances with TSO enabled
Enabling TSO can lead to abysmal performances when using seg6 in
encap mode, such as with the ixgbe driver. This patch adds a call to
iptunnel_handle_offloads() to remove the encapsulation bit if needed.

Before:
root@comp4-seg6bpf:~# iperf3 -c fc00::55
Connecting to host fc00::55, port 5201
[  4] local fc45::4 port 36592 connected to fc00::55 port 5201
[ ID] Interval           Transfer     Bandwidth       Retr  Cwnd
[  4]   0.00-1.00   sec   196 KBytes  1.60 Mbits/sec   47   6.66 KBytes
[  4]   1.00-2.00   sec   304 KBytes  2.49 Mbits/sec  100   5.33 KBytes
[  4]   2.00-3.00   sec   284 KBytes  2.32 Mbits/sec   92   5.33 KBytes

After:
root@comp4-seg6bpf:~# iperf3 -c fc00::55
Connecting to host fc00::55, port 5201
[  4] local fc45::4 port 43062 connected to fc00::55 port 5201
[ ID] Interval           Transfer     Bandwidth       Retr  Cwnd
[  4]   0.00-1.00   sec  1.03 GBytes  8.89 Gbits/sec    0    743 KBytes
[  4]   1.00-2.00   sec  1.03 GBytes  8.87 Gbits/sec    0    743 KBytes
[  4]   2.00-3.00   sec  1.03 GBytes  8.87 Gbits/sec    0    743 KBytes

Reported-by: Tom Herbert <tom@quantonium.net>
Fixes: 6c8702c60b ("ipv6: sr: add support for SRH encapsulation and injection with lwtunnels")
Signed-off-by: David Lebrun <dlebrun@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-30 14:14:33 -04:00
David Lebrun
8936ef7604 ipv6: sr: fix NULL pointer dereference when setting encap source address
When using seg6 in encap mode, we call ipv6_dev_get_saddr() to set the
source address of the outer IPv6 header, in case none was specified.
Using skb->dev can lead to BUG() when it is in an inconsistent state.
This patch uses the net_device attached to the skb's dst instead.

[940807.667429] BUG: unable to handle kernel NULL pointer dereference at 000000000000047c
[940807.762427] IP: ipv6_dev_get_saddr+0x8b/0x1d0
[940807.815725] PGD 0 P4D 0
[940807.847173] Oops: 0000 [#1] SMP PTI
[940807.890073] Modules linked in:
[940807.927765] CPU: 6 PID: 0 Comm: swapper/6 Tainted: G        W        4.16.0-rc1-seg6bpf+ #2
[940808.028988] Hardware name: HP ProLiant DL120 G6/ProLiant DL120 G6, BIOS O26    09/06/2010
[940808.128128] RIP: 0010:ipv6_dev_get_saddr+0x8b/0x1d0
[940808.187667] RSP: 0018:ffff88043fd836b0 EFLAGS: 00010206
[940808.251366] RAX: 0000000000000005 RBX: ffff88042cb1c860 RCX: 00000000000000fe
[940808.338025] RDX: 00000000000002c0 RSI: ffff88042cb1c860 RDI: 0000000000004500
[940808.424683] RBP: ffff88043fd83740 R08: 0000000000000000 R09: ffffffffffffffff
[940808.511342] R10: 0000000000000040 R11: 0000000000000000 R12: ffff88042cb1c850
[940808.598012] R13: ffffffff8208e380 R14: ffff88042ac8da00 R15: 0000000000000002
[940808.684675] FS:  0000000000000000(0000) GS:ffff88043fd80000(0000) knlGS:0000000000000000
[940808.783036] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[940808.852975] CR2: 000000000000047c CR3: 00000004255fe000 CR4: 00000000000006e0
[940808.939634] Call Trace:
[940808.970041]  <IRQ>
[940808.995250]  ? ip6t_do_table+0x265/0x640
[940809.043341]  seg6_do_srh_encap+0x28f/0x300
[940809.093516]  ? seg6_do_srh+0x1a0/0x210
[940809.139528]  seg6_do_srh+0x1a0/0x210
[940809.183462]  seg6_output+0x28/0x1e0
[940809.226358]  lwtunnel_output+0x3f/0x70
[940809.272370]  ip6_xmit+0x2b8/0x530
[940809.313185]  ? ac6_proc_exit+0x20/0x20
[940809.359197]  inet6_csk_xmit+0x7d/0xc0
[940809.404173]  tcp_transmit_skb+0x548/0x9a0
[940809.453304]  __tcp_retransmit_skb+0x1a8/0x7a0
[940809.506603]  ? ip6_default_advmss+0x40/0x40
[940809.557824]  ? tcp_current_mss+0x24/0x90
[940809.605925]  tcp_retransmit_skb+0xd/0x80
[940809.654016]  tcp_xmit_retransmit_queue.part.17+0xf9/0x210
[940809.719797]  tcp_ack+0xa47/0x1110
[940809.760612]  tcp_rcv_established+0x13c/0x570
[940809.812865]  tcp_v6_do_rcv+0x151/0x3d0
[940809.858879]  tcp_v6_rcv+0xa5c/0xb10
[940809.901770]  ? seg6_output+0xdd/0x1e0
[940809.946745]  ip6_input_finish+0xbb/0x460
[940809.994837]  ip6_input+0x74/0x80
[940810.034612]  ? ip6_rcv_finish+0xb0/0xb0
[940810.081663]  ipv6_rcv+0x31c/0x4c0
...

Fixes: 6c8702c60b ("ipv6: sr: add support for SRH encapsulation and injection with lwtunnels")
Reported-by: Tom Herbert <tom@quantonium.net>
Signed-off-by: David Lebrun <dlebrun@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-22 12:22:45 -04:00
David Lebrun
191f86ca8e ipv6: sr: fix scheduling in RCU when creating seg6 lwtunnel state
The seg6_build_state() function is called with RCU read lock held,
so we cannot use GFP_KERNEL. This patch uses GFP_ATOMIC instead.

[   92.770271] =============================
[   92.770628] WARNING: suspicious RCU usage
[   92.770921] 4.16.0-rc4+ #12 Not tainted
[   92.771277] -----------------------------
[   92.771585] ./include/linux/rcupdate.h:302 Illegal context switch in RCU read-side critical section!
[   92.772279]
[   92.772279] other info that might help us debug this:
[   92.772279]
[   92.773067]
[   92.773067] rcu_scheduler_active = 2, debug_locks = 1
[   92.773514] 2 locks held by ip/2413:
[   92.773765]  #0:  (rtnl_mutex){+.+.}, at: [<00000000e5461720>] rtnetlink_rcv_msg+0x441/0x4d0
[   92.774377]  #1:  (rcu_read_lock){....}, at: [<00000000df4f161e>] lwtunnel_build_state+0x59/0x210
[   92.775065]
[   92.775065] stack backtrace:
[   92.775371] CPU: 0 PID: 2413 Comm: ip Not tainted 4.16.0-rc4+ #12
[   92.775791] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1.fc27 04/01/2014
[   92.776608] Call Trace:
[   92.776852]  dump_stack+0x7d/0xbc
[   92.777130]  __schedule+0x133/0xf00
[   92.777393]  ? unwind_get_return_address_ptr+0x50/0x50
[   92.777783]  ? __sched_text_start+0x8/0x8
[   92.778073]  ? rcu_is_watching+0x19/0x30
[   92.778383]  ? kernel_text_address+0x49/0x60
[   92.778800]  ? __kernel_text_address+0x9/0x30
[   92.779241]  ? unwind_get_return_address+0x29/0x40
[   92.779727]  ? pcpu_alloc+0x102/0x8f0
[   92.780101]  _cond_resched+0x23/0x50
[   92.780459]  __mutex_lock+0xbd/0xad0
[   92.780818]  ? pcpu_alloc+0x102/0x8f0
[   92.781194]  ? seg6_build_state+0x11d/0x240
[   92.781611]  ? save_stack+0x9b/0xb0
[   92.781965]  ? __ww_mutex_wakeup_for_backoff+0xf0/0xf0
[   92.782480]  ? seg6_build_state+0x11d/0x240
[   92.782925]  ? lwtunnel_build_state+0x1bd/0x210
[   92.783393]  ? ip6_route_info_create+0x687/0x1640
[   92.783846]  ? ip6_route_add+0x74/0x110
[   92.784236]  ? inet6_rtm_newroute+0x8a/0xd0

Fixes: 6c8702c60b ("ipv6: sr: add support for SRH encapsulation and injection with lwtunnels")
Signed-off-by: David Lebrun <dlebrun@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-22 12:21:11 -04:00
David Lebrun
38ee7f2d47 ipv6: sr: add support for encapsulation of L2 frames
This patch implements the L2 frame encapsulation mechanism, referred to
as T.Encaps.L2 in the SRv6 specifications [1].

A new type of SRv6 tunnel mode is added (SEG6_IPTUN_MODE_L2ENCAP). It only
accepts packets with an existing MAC header (i.e., it will not work for
locally generated packets). The resulting packet looks like IPv6 -> SRH ->
Ethernet -> original L3 payload. The next header field of the SRH is set to
NEXTHDR_NONE.

[1] https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-01

Signed-off-by: David Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 17:10:23 -07:00
David Lebrun
32d99d0b67 ipv6: sr: add support for ip4ip6 encapsulation
This patch enables the SRv6 encapsulation mode to carry an IPv4 payload.
All the infrastructure was already present, I just had to add a parameter
to seg6_do_srh_encap() to specify the inner packet protocol, and perform
some additional checks.

Usage example:
ip route add 1.2.3.4 encap seg6 mode encap segs fc00::1,fc00::2 dev eth0

Signed-off-by: David Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-25 17:10:23 -07:00
David Lebrun
b04c80d3a7 ipv6: sr: export SRH insertion functions
This patch exports the seg6_do_srh_encap() and seg6_do_srh_inline()
functions. It also removes the CONFIG_IPV6_SEG6_INLINE knob
that enabled the compilation of seg6_do_srh_inline(). This function
is now built-in.

Signed-off-by: David Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-07 14:16:21 -07:00
David Ahern
9ae2872748 net: add extack arg to lwtunnel build state
Pass extack arg down to lwtunnel_build_state and the build_state callbacks.
Add messages for failures in lwtunnel_build_state, and add the extarg to
nla_parse where possible in the build_state callbacks.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-30 11:55:32 -04:00
David Lebrun
af3b5158b8 ipv6: sr: fix BUG due to headroom too small after SRH push
When a locally generated packet receives an SRH with two or more segments,
the remaining headroom is too small to push an ethernet header. This patch
ensures that the headroom is large enough after SRH push.

The BUG generated the following trace.

[  192.950285] skbuff: skb_under_panic: text:ffffffff81809675 len:198 put:14 head:ffff88006f306400 data:ffff88006f3063fa tail:0xc0 end:0x2c0 dev:A-1
[  192.952456] ------------[ cut here ]------------
[  192.953218] kernel BUG at net/core/skbuff.c:105!
[  192.953411] invalid opcode: 0000 [#1] PREEMPT SMP
[  192.953411] Modules linked in:
[  192.953411] CPU: 5 PID: 3433 Comm: ping6 Not tainted 4.11.0-rc3+ #237
[  192.953411] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.1-0-g8891697-prebuilt.qemu-project.org 04/01/2014
[  192.953411] task: ffff88007c2d42c0 task.stack: ffffc90000ef4000
[  192.953411] RIP: 0010:skb_panic+0x61/0x70
[  192.953411] RSP: 0018:ffffc90000ef7900 EFLAGS: 00010286
[  192.953411] RAX: 0000000000000085 RBX: 00000000000086dd RCX: 0000000000000201
[  192.953411] RDX: 0000000080000201 RSI: ffffffff81d104c5 RDI: 00000000ffffffff
[  192.953411] RBP: ffffc90000ef7920 R08: 0000000000000001 R09: 0000000000000000
[  192.953411] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[  192.953411] R13: ffff88007c5a4000 R14: ffff88007b363d80 R15: 00000000000000b8
[  192.953411] FS:  00007f94b558b700(0000) GS:ffff88007fd40000(0000) knlGS:0000000000000000
[  192.953411] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  192.953411] CR2: 00007fff5ecd5080 CR3: 0000000074141000 CR4: 00000000001406e0
[  192.953411] Call Trace:
[  192.953411]  skb_push+0x3b/0x40
[  192.953411]  eth_header+0x25/0xc0
[  192.953411]  neigh_resolve_output+0x168/0x230
[  192.953411]  ? ip6_finish_output2+0x242/0x8f0
[  192.953411]  ip6_finish_output2+0x242/0x8f0
[  192.953411]  ? ip6_finish_output2+0x76/0x8f0
[  192.953411]  ip6_finish_output+0xa8/0x1d0
[  192.953411]  ip6_output+0x64/0x2d0
[  192.953411]  ? ip6_output+0x73/0x2d0
[  192.953411]  ? ip6_dst_check+0xb5/0xc0
[  192.953411]  ? dst_cache_per_cpu_get.isra.2+0x40/0x80
[  192.953411]  seg6_output+0xb0/0x220
[  192.953411]  lwtunnel_output+0xcf/0x210
[  192.953411]  ? lwtunnel_output+0x59/0x210
[  192.953411]  ip6_local_out+0x38/0x70
[  192.953411]  ip6_send_skb+0x2a/0xb0
[  192.953411]  ip6_push_pending_frames+0x48/0x50
[  192.953411]  rawv6_sendmsg+0xa39/0xf10
[  192.953411]  ? __lock_acquire+0x489/0x890
[  192.953411]  ? __mutex_lock+0x1fc/0x970
[  192.953411]  ? __lock_acquire+0x489/0x890
[  192.953411]  ? __mutex_lock+0x1fc/0x970
[  192.953411]  ? tty_ioctl+0x283/0xec0
[  192.953411]  inet_sendmsg+0x45/0x1d0
[  192.953411]  ? _copy_from_user+0x54/0x80
[  192.953411]  sock_sendmsg+0x33/0x40
[  192.953411]  SYSC_sendto+0xef/0x170
[  192.953411]  ? entry_SYSCALL_64_fastpath+0x5/0xc2
[  192.953411]  ? trace_hardirqs_on_caller+0x12b/0x1b0
[  192.953411]  ? trace_hardirqs_on_thunk+0x1a/0x1c
[  192.953411]  SyS_sendto+0x9/0x10
[  192.953411]  entry_SYSCALL_64_fastpath+0x1f/0xc2
[  192.953411] RIP: 0033:0x7f94b453db33
[  192.953411] RSP: 002b:00007fff5ecd0578 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
[  192.953411] RAX: ffffffffffffffda RBX: 00007fff5ecd16e0 RCX: 00007f94b453db33
[  192.953411] RDX: 0000000000000040 RSI: 000055a78352e9c0 RDI: 0000000000000003
[  192.953411] RBP: 00007fff5ecd1690 R08: 000055a78352c940 R09: 000000000000001c
[  192.953411] R10: 0000000000000000 R11: 0000000000000246 R12: 000055a783321e10
[  192.953411] R13: 000055a7839890c0 R14: 0000000000000004 R15: 0000000000000000
[  192.953411] Code: 00 00 48 89 44 24 10 8b 87 c4 00 00 00 48 89 44 24 08 48 8b 87 d8 00 00 00 48 c7 c7 90 58 d2 81 48 89 04 24 31 c0 e8 4f 70 9a ff <0f> 0b 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 00 48 8b 97 d8 00 00
[  192.953411] RIP: skb_panic+0x61/0x70 RSP: ffffc90000ef7900
[  193.000186] ---[ end trace bd0b89fabdf2f92c ]---
[  193.000951] Kernel panic - not syncing: Fatal exception in interrupt
[  193.001137] Kernel Offset: disabled
[  193.001169] ---[ end Kernel panic - not syncing: Fatal exception in interrupt

Fixes: 19d5a26f5e ("ipv6: sr: expand skb head only if necessary")
Signed-off-by: David Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-17 15:33:53 -04:00
Johannes Berg
fceb6435e8 netlink: pass extended ACK struct to parsing functions
Pass the new extended ACK reporting struct to all of the generic
netlink parsing functions. For now, pass NULL in almost all callers
(except for some in the core.)

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-13 13:58:22 -04:00
David Lebrun
402a5bc462 ipv6: sr: select DST_CACHE by default
When CONFIG_IPV6_SEG6_LWTUNNEL is selected, automatically select DST_CACHE.
This allows to remove multiple ifdefs.

Signed-off-by: David Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-27 16:05:06 -07:00
David Lebrun
af4a2209b1 ipv6: sr: use dst_cache in seg6_input
We already use dst_cache in seg6_output, when handling locally generated
packets. We extend it in seg6_input, to also handle forwarded packets, and avoid
unnecessary fib lookups.

Performances for SRH encapsulation before the patch:
Result: OK: 5656067(c5655678+d388) usec, 5000000 (1000byte,0frags)
  884006pps 7072Mb/sec (7072048000bps) errors: 0

Performances after the patch:
Result: OK: 4774543(c4774084+d459) usec, 5000000 (1000byte,0frags)
  1047220pps 8377Mb/sec (8377760000bps) errors: 0

Signed-off-by: David Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-24 14:47:32 -07:00
David Lebrun
19d5a26f5e ipv6: sr: expand skb head only if necessary
To insert or encapsulate a packet with an SRH, we need a large enough skb
headroom. Currently, we are using pskb_expand_head to inconditionally increase
the size of the headroom by the amount needed by the SRH (and IPv6 header).
If this reallocation is performed by another CPU than the one that initially
allocated the skb, then when the initial CPU kfree the skb, it will enter the
__slab_free slowpath, impacting performances.

This patch replaces pskb_expand_head with skb_cow_head, that will reallocate the
skb head only if the headroom is not large enough.

Performances for SRH encapsulation before the patch:
Result: OK: 7348320(c7347271+d1048) usec, 5000000 (1000byte,0frags)
  680427pps 5443Mb/sec (5443416000bps) errors: 0

Performances after the patch:
Result: OK: 5656067(c5655678+d388) usec, 5000000 (1000byte,0frags)
  884006pps 7072Mb/sec (7072048000bps) errors: 0

Signed-off-by: David Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-24 14:47:32 -07:00
Wei Yongjun
bb4005bae3 ipv6: sr: fix non static symbol warnings
Fixes the following sparse warnings:

net/ipv6/seg6_iptunnel.c:58:5: warning:
 symbol 'nla_put_srh' was not declared. Should it be static?
net/ipv6/seg6_iptunnel.c:238:5: warning:
 symbol 'seg6_input' was not declared. Should it be static?
net/ipv6/seg6_iptunnel.c:254:5: warning:
 symbol 'seg6_output' was not declared. Should it be static?

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-07 11:42:35 -05:00
David Ahern
30357d7d8a lwtunnel: remove device arg to lwtunnel_build_state
Nothing about lwt state requires a device reference, so remove the
input argument.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-30 15:14:22 -05:00
Robert Shearman
88ff7334f2 net: Specify the owning module for lwtunnel ops
Modules implementing lwtunnel ops should not be allowed to unload
while there is state alive using those ops, so specify the owning
module for all lwtunnel ops.

Signed-off-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-24 16:21:36 -05:00
David Lebrun
fa79581ea6 ipv6: sr: fix several BUGs when preemption is enabled
When CONFIG_PREEMPT=y, CONFIG_IPV6=m and CONFIG_SEG6_HMAC=y,
seg6_hmac_init() is called during the initialization of the ipv6 module.
This causes a subsequent call to smp_processor_id() with preemption
enabled, resulting in the following trace.

[   20.451460] BUG: using smp_processor_id() in preemptible [00000000] code: systemd/1
[   20.452556] caller is debug_smp_processor_id+0x17/0x19
[   20.453304] CPU: 0 PID: 1 Comm: systemd Not tainted 4.9.0-rc5-00973-g46738b1 #1
[   20.454406]  ffffc9000062fc18 ffffffff813607b2 0000000000000000 ffffffff81a7f782
[   20.455528]  ffffc9000062fc48 ffffffff813778dc 0000000000000000 00000000001dcf98
[   20.456539]  ffffffffa003bd08 ffffffff81af93e0 ffffc9000062fc58 ffffffff81377905
[   20.456539] Call Trace:
[   20.456539]  [<ffffffff813607b2>] dump_stack+0x63/0x7f
[   20.456539]  [<ffffffff813778dc>] check_preemption_disabled+0xd1/0xe3
[   20.456539]  [<ffffffff81377905>] debug_smp_processor_id+0x17/0x19
[   20.460260]  [<ffffffffa0061f3b>] seg6_hmac_init+0xfa/0x192 [ipv6]
[   20.460260]  [<ffffffffa0061ccc>] seg6_init+0x39/0x6f [ipv6]
[   20.460260]  [<ffffffffa006121a>] inet6_init+0x21a/0x321 [ipv6]
[   20.460260]  [<ffffffffa0061000>] ? 0xffffffffa0061000
[   20.460260]  [<ffffffff81000457>] do_one_initcall+0x8b/0x115
[   20.460260]  [<ffffffff811328a3>] do_init_module+0x53/0x1c4
[   20.460260]  [<ffffffff8110650a>] load_module+0x1153/0x14ec
[   20.460260]  [<ffffffff81106a7b>] SYSC_finit_module+0x8c/0xb9
[   20.460260]  [<ffffffff81106a7b>] ? SYSC_finit_module+0x8c/0xb9
[   20.460260]  [<ffffffff81106abc>] SyS_finit_module+0x9/0xb
[   20.460260]  [<ffffffff810014d1>] do_syscall_64+0x62/0x75
[   20.460260]  [<ffffffff816834f0>] entry_SYSCALL64_slow_path+0x25/0x25

Moreover, dst_cache_* functions also call smp_processor_id(), generating
a similar trace.

This patch uses raw_cpu_ptr() in seg6_hmac_init() rather than this_cpu_ptr()
and disable preemption when using dst_cache_* functions.

Signed-off-by: David Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-13 12:29:55 -05:00
David Lebrun
9baee83406 ipv6: sr: add calls to verify and insert HMAC signatures
This patch enables the verification of the HMAC signature for transiting
SR-enabled packets, and its insertion on encapsulated/injected SRH.

Signed-off-by: David Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-09 20:40:06 -05:00
David Lebrun
6c8702c60b ipv6: sr: add support for SRH encapsulation and injection with lwtunnels
This patch creates a new type of interfaceless lightweight tunnel (SEG6),
enabling the encapsulation and injection of SRH within locally emitted
packets and forwarded packets.

>From a configuration viewpoint, a seg6 tunnel would be configured as follows:

  ip -6 ro ad fc00::1/128 encap seg6 mode encap segs fc42::1,fc42::2,fc42::3 dev eth0

Any packet whose destination address is fc00::1 would thus be encapsulated
within an outer IPv6 header containing the SRH with three segments, and would
actually be routed to the first segment of the list. If `mode inline' was
specified instead of `mode encap', then the SRH would be directly inserted
after the IPv6 header without outer encapsulation.

The inline mode is only available if CONFIG_IPV6_SEG6_INLINE is enabled. This
feature was made configurable because direct header insertion may break
several mechanisms such as PMTUD or IPSec AH.

Signed-off-by: David Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-09 20:40:06 -05:00