net: ipv6: exthdrs: get rid of ipv6_skb_net()

Get rid of ipv6_skb_net() which is only used in ipv6_hop_ioam().

Signed-off-by: Justin Iurman <justin.iurman@uliege.be>
Link: https://lore.kernel.org/r

net: ipv6: exthdrs: get rid of ipv6_skb_net()

Get rid of ipv6_skb_net() which is only used in ipv6_hop_ioam().

Signed-off-by: Justin Iurman <justin.iurman@uliege.be>
Link: https://lore.kernel.org/r/20240308185343.39272-1-justin.iurman@uliege.be
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

show more ...

net: adopt skb_network_offset() and similar helpers

This is a cleanup patch, making code a bit more concise.

1) Use skb_network_offset(skb) in place of
(skb_network_header(skb) - skb->data)

net: adopt skb_network_offset() and similar helpers

This is a cleanup patch, making code a bit more concise.

1) Use skb_network_offset(skb) in place of
(skb_network_header(skb) - skb->data)

2) Use -skb_network_offset(skb) in place of
(skb->data - skb_network_header(skb))

3) Use skb_transport_offset(skb) in place of
(skb_transport_header(skb) - skb->data)

4) Use skb_inner_transport_offset(skb) in place of
(skb_inner_transport_header(skb) - skb->data)

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Edward Cree <ecree.xilinx@gmail.com> # for sfc
Signed-off-by: David S. Miller <davem@davemloft.net>

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ipv6/addrconf: annotate data-races around devconf fields (II)

Final (?) round of this series.

Annotate lockless reads on following devconf fields,
because they be changed concurrently from /proc/ne

ipv6/addrconf: annotate data-races around devconf fields (II)

Final (?) round of this series.

Annotate lockless reads on following devconf fields,
because they be changed concurrently from /proc/net/ipv6/conf.

- accept_dad
- optimistic_dad
- use_optimistic
- use_oif_addrs_only
- ra_honor_pio_life
- keep_addr_on_down
- ndisc_notify
- ndisc_evict_nocarrier
- suppress_frag_ndisc
- addr_gen_mode
- seg6_enabled
- ioam6_enabled
- ioam6_id
- ioam6_id_wide
- drop_unicast_in_l2_multicast
- mldv[12]_unsolicited_report_interval
- force_mld_version
- force_tllao
- accept_untracked_na
- drop_unsolicited_na
- accept_source_route

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net: exthdrs: ioam6: send trace event

If we're processing an IOAM Pre-allocated Trace Option-Type (the only
one supported currently), then send the trace as an ioam6 event to the
netlink multicast g

net: exthdrs: ioam6: send trace event

If we're processing an IOAM Pre-allocated Trace Option-Type (the only
one supported currently), then send the trace as an ioam6 event to the
netlink multicast group. This way, user space apps will be able to
collect IOAM data.

Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Justin Iurman <justin.iurman@uliege.be>
Signed-off-by: David S. Miller <davem@davemloft.net>

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Fix write to cloned skb in ipv6_hop_ioam()

ioam6_fill_trace_data() writes inside the skb payload without ensuring
it's writeable (e.g., not cloned). This function is called both from the
input and o

Fix write to cloned skb in ipv6_hop_ioam()

ioam6_fill_trace_data() writes inside the skb payload without ensuring
it's writeable (e.g., not cloned). This function is called both from the
input and output path. The output path (ioam6_iptunnel) already does the
check. This commit provides a fix for the input path, inside
ipv6_hop_ioam(). It also updates ip6_parse_tlv() to refresh the network
header pointer ("nh") when returning from ipv6_hop_ioam().

Fixes: 9ee11f0fff20 ("ipv6: ioam: Data plane support for Pre-allocated Trace")
Reported-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Justin Iurman <justin.iurman@uliege.be>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

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ipv6: exthdrs: Replace opencoded swap() implementation

Get a coccinelle warning as follows:
net/ipv6/exthdrs.c:800:29-30: WARNING opportunity for swap()

Use swap() to replace opencoded implementati

ipv6: exthdrs: Replace opencoded swap() implementation

Get a coccinelle warning as follows:
net/ipv6/exthdrs.c:800:29-30: WARNING opportunity for swap()

Use swap() to replace opencoded implementation.

Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Reviewed-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20230807020947.1991716-1-william.xuanziyang@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

show more ...

ipv6: rpl: Remove redundant skb_dst_drop().

RPL code has a pattern where skb_dst_drop() is called before
ip6_route_input().

However, ip6_route_input() calls skb_dst_drop() internally,
so we need no

ipv6: rpl: Remove redundant skb_dst_drop().

RPL code has a pattern where skb_dst_drop() is called before
ip6_route_input().

However, ip6_route_input() calls skb_dst_drop() internally,
so we need not call skb_dst_drop() before ip6_route_input().

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20230710213511.5364-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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ipv6: exthdrs: Remove redundant skb_headlen() check in ip6_parse_tlv().

ipv6_destopt_rcv() and ipv6_parse_hopopts() pulls these data

- Hop-by-Hop/Destination Options Header : 8
- Hdr Ext Len

ipv6: exthdrs: Remove redundant skb_headlen() check in ip6_parse_tlv().

ipv6_destopt_rcv() and ipv6_parse_hopopts() pulls these data

- Hop-by-Hop/Destination Options Header : 8
- Hdr Ext Len : skb_transport_header(skb)[1] << 3

and calls ip6_parse_tlv(), so it need not check if skb_headlen() is less
than skb_transport_offset(skb) + (skb_transport_header(skb)[1] << 3).

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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ipv6: exthdrs: Reload hdr only when needed in ipv6_srh_rcv().

We need not reload hdr in ipv6_srh_rcv() unless we call
pskb_expand_head().

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed

ipv6: exthdrs: Reload hdr only when needed in ipv6_srh_rcv().

We need not reload hdr in ipv6_srh_rcv() unless we call
pskb_expand_head().

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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ipv6: exthdrs: Replace pskb_pull() with skb_pull() in ipv6_srh_rcv().

ipv6_rthdr_rcv() pulls these data

- Segment Routing Header : 8
- Hdr Ext Len : skb_transport_header(skb)[1] << 3

ipv6: exthdrs: Replace pskb_pull() with skb_pull() in ipv6_srh_rcv().

ipv6_rthdr_rcv() pulls these data

- Segment Routing Header : 8
- Hdr Ext Len : skb_transport_header(skb)[1] << 3

needed by ipv6_srh_rcv(), so pskb_pull() in ipv6_srh_rcv() never
fails and can be replaced with skb_pull().

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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ipv6: rpl: Remove redundant multicast tests in ipv6_rpl_srh_rcv().

ipv6_rpl_srh_rcv() checks if ipv6_hdr(skb)->daddr or ohdr->rpl_segaddr[i]
is the multicast address with ipv6_addr_type().

We have

ipv6: rpl: Remove redundant multicast tests in ipv6_rpl_srh_rcv().

ipv6_rpl_srh_rcv() checks if ipv6_hdr(skb)->daddr or ohdr->rpl_segaddr[i]
is the multicast address with ipv6_addr_type().

We have the same check for ipv6_hdr(skb)->daddr in ipv6_rthdr_rcv(), so we
need not recheck it in ipv6_rpl_srh_rcv().

Also, we should use ipv6_addr_is_multicast() for ohdr->rpl_segaddr[i]
instead of ipv6_addr_type().

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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ipv6: rpl: Remove pskb(_may)?_pull() in ipv6_rpl_srh_rcv().

As Eric Dumazet pointed out [0], ipv6_rthdr_rcv() pulls these data

- Segment Routing Header : 8
- Hdr Ext Len : skb_transp

ipv6: rpl: Remove pskb(_may)?_pull() in ipv6_rpl_srh_rcv().

As Eric Dumazet pointed out [0], ipv6_rthdr_rcv() pulls these data

- Segment Routing Header : 8
- Hdr Ext Len : skb_transport_header(skb)[1] << 3

needed by ipv6_rpl_srh_rcv(). We can remove pskb_may_pull() and
replace pskb_pull() with skb_pull() in ipv6_rpl_srh_rcv().

Link: https://lore.kernel.org/netdev/CANn89iLboLwLrHXeHJucAqBkEL_S0rJFog68t7wwwXO-aNf5Mg@mail.gmail.com/ [0]
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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ipv6: rpl: Fix Route of Death.

A remote DoS vulnerability of RPL Source Routing is assigned CVE-2023-2156.

The Source Routing Header (SRH) has the following format:

0 1

ipv6: rpl: Fix Route of Death.

A remote DoS vulnerability of RPL Source Routing is assigned CVE-2023-2156.

The Source Routing Header (SRH) has the following format:

0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Next Header | Hdr Ext Len | Routing Type | Segments Left |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| CmprI | CmprE | Pad | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. .
. Addresses[1..n] .
. .
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

The originator of an SRH places the first hop's IPv6 address in the IPv6
header's IPv6 Destination Address and the second hop's IPv6 address as
the first address in Addresses[1..n].

The CmprI and CmprE fields indicate the number of prefix octets that are
shared with the IPv6 Destination Address. When CmprI or CmprE is not 0,
Addresses[1..n] are compressed as follows:

1..n-1 : (16 - CmprI) bytes
n : (16 - CmprE) bytes

Segments Left indicates the number of route segments remaining. When the
value is not zero, the SRH is forwarded to the next hop. Its address
is extracted from Addresses[n - Segment Left + 1] and swapped with IPv6
Destination Address.

When Segment Left is greater than or equal to 2, the size of SRH is not
changed because Addresses[1..n-1] are decompressed and recompressed with
CmprI.

OTOH, when Segment Left changes from 1 to 0, the new SRH could have a
different size because Addresses[1..n-1] are decompressed with CmprI and
recompressed with CmprE.

Let's say CmprI is 15 and CmprE is 0. When we receive SRH with Segment
Left >= 2, Addresses[1..n-1] have 1 byte for each, and Addresses[n] has
16 bytes. When Segment Left is 1, Addresses[1..n-1] is decompressed to
16 bytes and not recompressed. Finally, the new SRH will need more room
in the header, and the size is (16 - 1) * (n - 1) bytes.

Here the max value of n is 255 as Segment Left is u8, so in the worst case,
we have to allocate 3825 bytes in the skb headroom. However, now we only
allocate a small fixed buffer that is IPV6_RPL_SRH_WORST_SWAP_SIZE (16 + 7
bytes). If the decompressed size overflows the room, skb_push() hits BUG()
below [0].

Instead of allocating the fixed buffer for every packet, let's allocate
enough headroom only when we receive SRH with Segment Left 1.

[0]:
skbuff: skb_under_panic: text:ffffffff81c9f6e2 len:576 put:576 head:ffff8880070b5180 data:ffff8880070b4fb0 tail:0x70 end:0x140 dev:lo
kernel BUG at net/core/skbuff.c:200!
invalid opcode: 0000 [#1] PREEMPT SMP PTI
CPU: 0 PID: 154 Comm: python3 Not tainted 6.4.0-rc4-00190-gc308e9ec0047 #7
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
RIP: 0010:skb_panic (net/core/skbuff.c:200)
Code: 4f 70 50 8b 87 bc 00 00 00 50 8b 87 b8 00 00 00 50 ff b7 c8 00 00 00 4c 8b 8f c0 00 00 00 48 c7 c7 80 6e 77 82 e8 ad 8b 60 ff <0f> 0b 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000003da0 EFLAGS: 00000246
RAX: 0000000000000085 RBX: ffff8880058a6600 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff88807dc1c540 RDI: ffff88807dc1c540
RBP: ffffc90000003e48 R08: ffffffff82b392c8 R09: 00000000ffffdfff
R10: ffffffff82a592e0 R11: ffffffff82b092e0 R12: ffff888005b1c800
R13: ffff8880070b51b8 R14: ffff888005b1ca18 R15: ffff8880070b5190
FS: 00007f4539f0b740(0000) GS:ffff88807dc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055670baf3000 CR3: 0000000005b0e000 CR4: 00000000007506f0
PKRU: 55555554
Call Trace:
<IRQ>
skb_push (net/core/skbuff.c:210)
ipv6_rthdr_rcv (./include/linux/skbuff.h:2880 net/ipv6/exthdrs.c:634 net/ipv6/exthdrs.c:718)
ip6_protocol_deliver_rcu (net/ipv6/ip6_input.c:437 (discriminator 5))
ip6_input_finish (./include/linux/rcupdate.h:805 net/ipv6/ip6_input.c:483)
__netif_receive_skb_one_core (net/core/dev.c:5494)
process_backlog (./include/linux/rcupdate.h:805 net/core/dev.c:5934)
__napi_poll (net/core/dev.c:6496)
net_rx_action (net/core/dev.c:6565 net/core/dev.c:6696)
__do_softirq (./arch/x86/include/asm/jump_label.h:27 ./include/linux/jump_label.h:207 ./include/trace/events/irq.h:142 kernel/softirq.c:572)
do_softirq (kernel/softirq.c:472 kernel/softirq.c:459)
</IRQ>
<TASK>
__local_bh_enable_ip (kernel/softirq.c:396)
__dev_queue_xmit (net/core/dev.c:4272)
ip6_finish_output2 (./include/net/neighbour.h:544 net/ipv6/ip6_output.c:134)
rawv6_sendmsg (./include/net/dst.h:458 ./include/linux/netfilter.h:303 net/ipv6/raw.c:656 net/ipv6/raw.c:914)
sock_sendmsg (net/socket.c:724 net/socket.c:747)
__sys_sendto (net/socket.c:2144)
__x64_sys_sendto (net/socket.c:2156 net/socket.c:2152 net/socket.c:2152)
do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120)
RIP: 0033:0x7f453a138aea
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 f3 0f 1e fa 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 15 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 7e c3 0f 1f 44 00 00 41 54 48 83 ec 30 44 89
RSP: 002b:00007ffcc212a1c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007ffcc212a288 RCX: 00007f453a138aea
RDX: 0000000000000060 RSI: 00007f4539084c20 RDI: 0000000000000003
RBP: 00007f4538308e80 R08: 00007ffcc212a300 R09: 000000000000001c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: ffffffffc4653600 R14: 0000000000000001 R15: 00007f4539712d1b
</TASK>
Modules linked in:

Fixes: 8610c7c6e3bd ("net: ipv6: add support for rpl sr exthdr")
Reported-by: Max VA
Closes: https://www.interruptlabs.co.uk/articles/linux-ipv6-route-of-death
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20230605180617.67284-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

show more ...

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_dro

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>

show more ...

net: ipv6: add skb drop reasons to TLV parse

Replace kfree_skb() used in TLV encoded option header parsing with
kfree_skb_reason(). Following functions are involved:

ip6_parse_tlv()
ipv6_hop_ra()
i

net: ipv6: add skb drop reasons to TLV parse

Replace kfree_skb() used in TLV encoded option header parsing with
kfree_skb_reason(). Following functions are involved:

ip6_parse_tlv()
ipv6_hop_ra()
ipv6_hop_ioam()
ipv6_hop_jumbo()
ipv6_hop_calipso()
ipv6_dest_hao()

Most skb drops during this process are regarded as 'InHdrErrors',
as 'IPSTATS_MIB_INHDRERRORS' is used when ip6_parse_tlv() fails,
which make we use 'SKB_DROP_REASON_IP_INHDR' correspondingly.

However, 'IP_INHDR' is a relatively general reason. Therefore, we
can use other reasons with higher priority in some cases. For example,
'SKB_DROP_REASON_UNHANDLED_PROTO' is used for unknown TLV options.

Signed-off-by: Menglong Dong <imagedong@tencent.com>
Reviewed-by: Jiang Biao <benbjiang@tencent.com>
Reviewed-by: Hao Peng <flyingpeng@tencent.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net: ipv6: remove redundant statistics in ipv6_hop_jumbo()

There are two call chains for ipv6_hop_jumbo(). The first one is:

ipv6_destopt_rcv() -> ip6_parse_tlv() -> ipv6_hop_jumbo()

On this call

net: ipv6: remove redundant statistics in ipv6_hop_jumbo()

There are two call chains for ipv6_hop_jumbo(). The first one is:

ipv6_destopt_rcv() -> ip6_parse_tlv() -> ipv6_hop_jumbo()

On this call chain, the drop statistics will be done in
ipv6_destopt_rcv() with 'IPSTATS_MIB_INHDRERRORS' if ipv6_hop_jumbo()
returns false.

The second call chain is:

ip6_rcv_core() -> ipv6_parse_hopopts() -> ip6_parse_tlv()

And the drop statistics will also be done in ip6_rcv_core() with
'IPSTATS_MIB_INHDRERRORS' if ipv6_hop_jumbo() returns false.

Therefore, the statistics in ipv6_hop_jumbo() is redundant, which
means the drop is counted twice. The statistics in ipv6_hop_jumbo()
is almost the same as the outside, except the
'IPSTATS_MIB_INTRUNCATEDPKTS', which seems that we have to ignore it.

Signed-off-by: Menglong Dong <imagedong@tencent.com>
Reviewed-by: Jiang Biao <benbjiang@tencent.com>
Reviewed-by: Hao Peng <flyingpeng@tencent.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

ipv6: exthdrs: use swap() instead of open coding it

Address the following coccicheck warning:
net/ipv6/exthdrs.c:620:44-45: WARNING opportunity for swap()

by using swap() for the swapping of variab

ipv6: exthdrs: use swap() instead of open coding it

Address the following coccicheck warning:
net/ipv6/exthdrs.c:620:44-45: WARNING opportunity for swap()

by using swap() for the swapping of variable values and drop
the tmp (`addr`) variable that is not needed any more.

Signed-off-by: Guo Zhengkui <guozhengkui@vivo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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ipv6: partially inline ipv6_fixup_options

Inline a part of ipv6_fixup_options() to avoid extra overhead on
function call if opt is NULL.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Revie

ipv6: partially inline ipv6_fixup_options

Inline a part of ipv6_fixup_options() to avoid extra overhead on
function call if opt is NULL.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

show more ...

ipv6: Remove duplicate statements

This statement is repeated with the initialization statement

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: luo penghao <luo.penghao@zte.com.cn>
Signed

ipv6: Remove duplicate statements

This statement is repeated with the initialization statement

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: luo penghao <luo.penghao@zte.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

ipv6: ioam: Distinguish input and output for hop-limit

This patch anticipates the support for the IOAM insertion inside in-transit
packets, by making a difference between input and output in order t

ipv6: ioam: Distinguish input and output for hop-limit

This patch anticipates the support for the IOAM insertion inside in-transit
packets, by making a difference between input and output in order to determine
the right value for its hop-limit (inherited from the IPv6 hop-limit).

Input case: happens before ip6_forward, the IPv6 hop-limit is not decremented
yet -> decrement the IOAM hop-limit to reflect the new hop inside the trace.

Output case: happens after ip6_forward, the IPv6 hop-limit has already been
decremented -> keep the same value for the IOAM hop-limit.

Signed-off-by: Justin Iurman <justin.iurman@uliege.be>
Signed-off-by: David S. Miller <davem@davemloft.net>

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ipv6: exthdrs: get rid of indirect calls in ip6_parse_tlv()

As presented last month in our "BIG TCP" talk at netdev 0x15,
we plan using IPv6 jumbograms.

One of the minor problem we talked about is

ipv6: exthdrs: get rid of indirect calls in ip6_parse_tlv()

As presented last month in our "BIG TCP" talk at netdev 0x15,
we plan using IPv6 jumbograms.

One of the minor problem we talked about is the fact that
ip6_parse_tlv() is currently using tables to list known tlvs,
thus using potentially expensive indirect calls.

While we could mitigate this cost using macros from
indirect_call_wrapper.h, we also can get rid of the tables
and let the compiler emit optimized code.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Justin Iurman <justin.iurman@uliege.be>
Cc: Coco Li <lixiaoyan@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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ipv6: ioam: Data plane support for Pre-allocated Trace

Implement support for processing the IOAM Pre-allocated Trace with IPv6,
see [1] and [2]. Introduce a new IPv6 Hop-by-Hop TLV option, see IANA

ipv6: ioam: Data plane support for Pre-allocated Trace

Implement support for processing the IOAM Pre-allocated Trace with IPv6,
see [1] and [2]. Introduce a new IPv6 Hop-by-Hop TLV option, see IANA [3].

A new per-interface sysctl is introduced. The value is a boolean to accept (=1)
or ignore (=0, by default) IPv6 IOAM options on ingress for an interface:
- net.ipv6.conf.XXX.ioam6_enabled

Two other sysctls are introduced to define IOAM IDs, represented by an integer.
They are respectively per-namespace and per-interface:
- net.ipv6.ioam6_id
- net.ipv6.conf.XXX.ioam6_id

The value of the first one represents the IOAM ID of the node itself (u32; max
and default value = U32_MAX>>8, due to hop limit concatenation) while the other
represents the IOAM ID of an interface (u16; max and default value = U16_MAX).

Each "ioam6_id" sysctl has a "_wide" equivalent:
- net.ipv6.ioam6_id_wide
- net.ipv6.conf.XXX.ioam6_id_wide

The value of the first one represents the wide IOAM ID of the node itself (u64;
max and default value = U64_MAX>>8, due to hop limit concatenation) while the
other represents the wide IOAM ID of an interface (u32; max and default value
= U32_MAX).

The use of short and wide equivalents is not exclusive, a deployment could
choose to leverage both. For example, net.ipv6.conf.XXX.ioam6_id (short format)
could be an identifier for a physical interface, whereas
net.ipv6.conf.XXX.ioam6_id_wide (wide format) could be an identifier for a
logical sub-interface. Documentation about new sysctls is provided at the end
of this patchset.

Two relativistic hash tables are used: one for IOAM namespaces, the other for
IOAM schemas. A namespace can only have a single active schema and a schema
can only be attached to a single namespace (1:1 relationship).

[1] https://tools.ietf.org/html/draft-ietf-ippm-ioam-ipv6-options
[2] https://tools.ietf.org/html/draft-ietf-ippm-ioam-data
[3] https://www.iana.org/assignments/ipv6-parameters/ipv6-parameters.xhtml#ipv6-parameters-2

Signed-off-by: Justin Iurman <justin.iurman@uliege.be>
Signed-off-by: David S. Miller <davem@davemloft.net>

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ipv6: fix out-of-bound access in ip6_parse_tlv()

First problem is that optlen is fetched without checking
there is more than one byte to parse.

Fix this by taking care of IPV6_TLV_PAD1 before
fetch

ipv6: fix out-of-bound access in ip6_parse_tlv()

First problem is that optlen is fetched without checking
there is more than one byte to parse.

Fix this by taking care of IPV6_TLV_PAD1 before
fetching optlen (under appropriate sanity checks against len)

Second problem is that IPV6_TLV_PADN checks of zero
padding are performed before the check of remaining length.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Fixes: c1412fce7ecc ("net/ipv6/exthdrs.c: Strict PadN option checking")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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ipv6: exthdrs: do not blindly use init_net

I see no reason why max_dst_opts_cnt and max_hbh_opts_cnt
are fetched from the initial net namespace.

The other sysctls (max_dst_opts_len & max_hbh_opts_l

ipv6: exthdrs: do not blindly use init_net

I see no reason why max_dst_opts_cnt and max_hbh_opts_cnt
are fetched from the initial net namespace.

The other sysctls (max_dst_opts_len & max_hbh_opts_len)
are in fact already using the current ns.

Note: it is not clear why ipv6_destopt_rcv() use two ways to
get to the netns :

1) dev_net(dst->dev)
Originally used to increment IPSTATS_MIB_INHDRERRORS

2) dev_net(skb->dev)
Tom used this variant in his patch.

Maybe this calls to use ipv6_skb_net() instead ?

Fixes: 47d3d7ac656a ("ipv6: Implement limits on Hop-by-Hop and Destination options")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Tom Herbert <tom@quantonium.net>
Cc: Coco Li <lixiaoyan@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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seg6: add support for IPv4 decapsulation in ipv6_srh_rcv()

As specified in IETF RFC 8754, section 4.3.1.2, if the upper layer
header is IPv4 or IPv6, perform IPv6 decapsulation and resubmit the
deca

seg6: add support for IPv4 decapsulation in ipv6_srh_rcv()

As specified in IETF RFC 8754, section 4.3.1.2, if the upper layer
header is IPv4 or IPv6, perform IPv6 decapsulation and resubmit the
decapsulated packet to the IPv4 or IPv6 module.
Only IPv6 decapsulation was implemented. This patch adds support for IPv4
decapsulation.

Link: https://tools.ietf.org/html/rfc8754#section-4.3.1.2
Signed-off-by: Julien Massonneau <julien.massonneau@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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