Commit Graph

5 Commits

Author SHA1 Message Date
Menglong Dong 73d5fd5a9f net: ip: add skb drop reasons for ip egress path
[upstream commit 5e187189ec324f78035d33a4bc123a9c4ca6f3e3]

Replace kfree_skb() which is used in the packet egress path of IP layer
with kfree_skb_reason(). Functions that are involved include:

__ip_queue_xmit()
ip_finish_output()
ip_mc_finish_output()
ip6_output()
ip6_finish_output()
ip6_finish_output2()

Following new drop reasons are introduced:

SKB_DROP_REASON_IP_OUTNOROUTES
SKB_DROP_REASON_BPF_CGROUP_EGRESS
SKB_DROP_REASON_IPV6DISABLED
SKB_DROP_REASON_NEIGH_CREATEFAIL

Reviewed-by: Mengen Sun <mengensun@tencent.com>
Reviewed-by: Hao Peng <flyingpeng@tencent.com>
Signed-off-by: Menglong Dong <imagedong@tencent.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-06-17 10:08:50 +08:00
Florian Westphal 5a4166c594 net: ip: always refragment ip defragmented packets
[ Upstream commit bb4cc1a18856a73f0ff5137df0c2a31f4c50f6cf ]

Conntrack reassembly records the largest fragment size seen in IPCB.
However, when this gets forwarded/transmitted, fragmentation will only
be forced if one of the fragmented packets had the DF bit set.

In that case, a flag in IPCB will force fragmentation even if the
MTU is large enough.

This should work fine, but this breaks with ip tunnels.
Consider client that sends a UDP datagram of size X to another host.

The client fragments the datagram, so two packets, of size y and z, are
sent. DF bit is not set on any of these packets.

Middlebox netfilter reassembles those packets back to single size-X
packet, before routing decision.

packet-size-vs-mtu checks in ip_forward are irrelevant, because DF bit
isn't set.  At output time, ip refragmentation is skipped as well
because x is still smaller than the mtu of the output device.

If ttransmit device is an ip tunnel, the packet size increases to
x+overhead.

Also, tunnel might be configured to force DF bit on outer header.

In this case, packet will be dropped (exceeds MTU) and an ICMP error is
generated back to sender.

But sender already respects the announced MTU, all the packets that
it sent did fit the announced mtu.

Force refragmentation as per original sizes unconditionally so ip tunnel
will encapsulate the fragments instead.

The only other solution I see is to place ip refragmentation in
the ip_tunnel code to handle this case.

Fixes: d6b915e29f4ad ("ip_fragment: don't forward defragmented DF packet")
Reported-by: Christian Perle <christian.perle@secunet.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-12 12:51:16 +08:00
Wei Wang ab734990c6 ip: fix tos reflection in ack and reset packets
[ Upstream commit ba9e04a7ddf4f22a10e05bf9403db6b97743c7bf ]

Currently, in tcp_v4_reqsk_send_ack() and tcp_v4_send_reset(), we
echo the TOS value of the received packets in the response.
However, we do not want to echo the lower 2 ECN bits in accordance
with RFC 3168 6.1.5 robustness principles.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")

Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-16 16:36:25 +08:00
Willem de Bruijn f543d08241 ip: Fix SO_MARK in RST, ACK and ICMP packets
[ Upstream commit 0da7536fb47f51df89ccfcb1fa09f249d9accec5 ]

When no full socket is available, skbs are sent over a per-netns
control socket. Its sk_mark is temporarily adjusted to match that
of the real (request or timewait) socket or to reflect an incoming
skb, so that the outgoing skb inherits this in __ip_make_skb.

Introduction of the socket cookie mark field broke this. Now the
skb is set through the cookie and cork:

<caller>		# init sockc.mark from sk_mark or cmsg
ip_append_data
  ip_setup_cork		# convert sockc.mark to cork mark
ip_push_pending_frames
  ip_finish_skb
    __ip_make_skb	# set skb->mark to cork mark

But I missed these special control sockets. Update all callers of
__ip(6)_make_skb that were originally missed.

For IPv6, the same two icmp(v6) paths are affected. The third
case is not, as commit 92e55f412cff ("tcp: don't annotate
mark on control socket from tcp_v6_send_response()") replaced
the ctl_sk->sk_mark with passing the mark field directly as a
function argument. That commit predates the commit that
introduced the bug.

Fixes: c6af0c227a22 ("ip: support SO_MARK cmsg")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Reported-by: Martin KaFai Lau <kafai@fb.com>
Reviewed-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-16 16:31:46 +08:00
Kaixu Xia 590eaf1fec Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.
Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
2021-03-16 11:01:34 +08:00