linux-toradex.git/net/ipv4/ip_input.c, branch v5.19-rc1

net-core: rx_otherhost_dropped to core_stats

2022-04-08T03:32:49+00:00

Increment rx_otherhost_dropped counter when packet dropped due to
mismatched dest MAC addr.

An example when this drop can occur is when manually crafting raw
packets that will be consumed by a user space application via a tap
device. For testing purposes local traffic was generated using trafgen
for the client and netcat to start a server

Tested: Created 2 netns, sent 1 packet using trafgen from 1 to the other
with "{eth(daddr=$INCORRECT_MAC...}", verified that iproute2 showed the
counter was incremented. (Also had to modify iproute2 to show the stat,
additional patch for that coming next.)

Signed-off-by: Jeffrey Ji 
Reviewed-by: Brian Vazquez 
Reviewed-by: Eric Dumazet 
Link: https://lore.kernel.org/r/20220406172600.1141083-1-jeffreyjilinux@gmail.com
Signed-off-by: Jakub Kicinski

net: Postpone skb_clear_delivery_time() until knowing the skb is delivered locally

2022-03-03T14:38:48+00:00

The previous patches handled the delivery_time in the ingress path
before the routing decision is made.  This patch can postpone clearing
delivery_time in a skb until knowing it is delivered locally and also
set the (rcv) timestamp if needed.  This patch moves the
skb_clear_delivery_time() from dev.c to ip_local_deliver_finish()
and ip6_input_finish().

Signed-off-by: Martin KaFai Lau 
Signed-off-by: David S. Miller

net: ipv4: use kfree_skb_reason() in ip_protocol_deliver_rcu()

2022-02-07T11:18:49+00:00

Replace kfree_skb() with kfree_skb_reason() in ip_protocol_deliver_rcu().
Following new drop reasons are introduced:

SKB_DROP_REASON_XFRM_POLICY
SKB_DROP_REASON_IP_NOPROTO

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

net: ipv4: use kfree_skb_reason() in ip_rcv_finish_core()

2022-02-07T11:18:49+00:00

Replace kfree_skb() with kfree_skb_reason() in ip_rcv_finish_core(),
following drop reasons are introduced:

SKB_DROP_REASON_IP_RPFILTER
SKB_DROP_REASON_UNICAST_IN_L2_MULTICAST

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

net: ipv4: use kfree_skb_reason() in ip_rcv_core()

2022-02-07T11:18:49+00:00

Replace kfree_skb() with kfree_skb_reason() in ip_rcv_core(). Three new
drop reasons are introduced:

SKB_DROP_REASON_OTHERHOST
SKB_DROP_REASON_IP_CSUM
SKB_DROP_REASON_IP_INHDR

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

net: use indirect call helpers for dst_input

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

This patch avoids the indirect call for the common case:
ip_local_deliver and ip6_input

Signed-off-by: Brian Vazquez 
Signed-off-by: Jakub Kicinski

bpf: Add socket assign support

2020-03-30T20:45:04+00:00

Add support for TPROXY via a new bpf helper, bpf_sk_assign().

This helper requires the BPF program to discover the socket via a call
to bpf_sk*_lookup_*(), then pass this socket to the new helper. The
helper takes its own reference to the socket in addition to any existing
reference that may or may not currently be obtained for the duration of
BPF processing. For the destination socket to receive the traffic, the
traffic must be routed towards that socket via local route. The
simplest example route is below, but in practice you may want to route
traffic more narrowly (eg by CIDR):

  $ ip route add local default dev lo

This patch avoids trying to introduce an extra bit into the skb->sk, as
that would require more invasive changes to all code interacting with
the socket to ensure that the bit is handled correctly, such as all
error-handling cases along the path from the helper in BPF through to
the orphan path in the input. Instead, we opt to use the destructor
variable to switch on the prefetch of the socket.

Signed-off-by: Joe Stringer 
Signed-off-by: Alexei Starovoitov 
Acked-by: Martin KaFai Lau 
Link: https://lore.kernel.org/bpf/20200329225342.16317-2-joe@wand.net.nz

ipv4: use dst hint for ipv4 list receive

2019-11-21T22:45:55+00:00

This is alike the previous change, with some additional ipv4 specific
quirk. Even when using the route hint we still have to do perform
additional per packet checks about source address validity: a new
helper is added to wrap them.

Hints are explicitly disabled if the destination is a local broadcast,
that keeps the code simple and local broadcast are a slower path anyway.

UDP flood performances vs recvmmsg() receiver:

vanilla		patched		delta
Kpps		Kpps		%
1683		1871		+11

In the worst case scenario - each packet has a different
destination address - the performance delta is within noise
range.

v3 -> v4:
 - re-enable hints for forward

v2 -> v3:
 - really fix build (sic) and hint usage check
 - use fib4_has_custom_rules() helpers (David A.)
 - add ip_extract_route_hint() helper (Edward C.)
 - use prev skb as hint instead of copying data (Willem)

v1 -> v2:
 - fix build issue with !CONFIG_IP_MULTIPLE_TABLES

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

inet: do not call sublist_rcv on empty list

2019-10-30T00:54:29+00:00

syzbot triggered struct net NULL deref in NF_HOOK_LIST:
RIP: 0010:NF_HOOK_LIST include/linux/netfilter.h:331 [inline]
RIP: 0010:ip6_sublist_rcv+0x5c9/0x930 net/ipv6/ip6_input.c:292
 ipv6_list_rcv+0x373/0x4b0 net/ipv6/ip6_input.c:328
 __netif_receive_skb_list_ptype net/core/dev.c:5274 [inline]

Reason:
void ipv6_list_rcv(struct list_head *head, struct packet_type *pt,
                   struct net_device *orig_dev)
[..]
        list_for_each_entry_safe(skb, next, head, list) {
		/* iterates list */
                skb = ip6_rcv_core(skb, dev, net);
		/* ip6_rcv_core drops skb -> NULL is returned */
                if (skb == NULL)
                        continue;
	[..]
	}
	/* sublist is empty -> curr_net is NULL */
        ip6_sublist_rcv(&sublist, curr_dev, curr_net);

Before the recent change NF_HOOK_LIST did a list iteration before
struct net deref, i.e. it was a no-op in the empty list case.

List iteration now happens after *net deref, causing crash.

Follow the same pattern as the ip(v6)_list_rcv loop and add a list_empty
test for the final sublist dispatch too.

Cc: Edward Cree 
Reported-by: syzbot+c54f457cad330e57e967@syzkaller.appspotmail.com
Fixes: ca58fbe06c54 ("netfilter: add and use nf_hook_slow_list()")
Signed-off-by: Florian Westphal 
Tested-by: Leon Romanovsky 
Tested-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller

netfilter: drop bridge nf reset from nf_reset

2019-10-01T16:42:15+00:00

commit 174e23810cd31
("sk_buff: drop all skb extensions on free and skb scrubbing") made napi
recycle always drop skb extensions.  The additional skb_ext_del() that is
performed via nf_reset on napi skb recycle is not needed anymore.

Most nf_reset() calls in the stack are there so queued skb won't block
'rmmod nf_conntrack' indefinitely.

This removes the skb_ext_del from nf_reset, and renames it to a more
fitting nf_reset_ct().

In a few selected places, add a call to skb_ext_reset to make sure that
no active extensions remain.

I am submitting this for "net", because we're still early in the release
cycle.  The patch applies to net-next too, but I think the rename causes
needless divergence between those trees.

Suggested-by: Eric Dumazet 
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso