kernel/linux.git/net/ipv6/netfilter.c, branch v6.19.11

netfilter: Switch to skb_dstref_steal to clear dst_entry

2025-08-20T00:54:19+00:00

Going forward skb_dst_set will assert that skb dst_entry is empty during skb_dst_set. skb_dstref_steal is added to reset existing entry without doing refcnt. Switch to skb_dstref_steal in ip[6]_route_me_harder and add a comment on why it's safe to skip skb_dstref_restore. Acked-by: Florian Westphal Signed-off-by: Stanislav Fomichev Link: https://patch.msgid.link/20250818154032.3173645-4-sdf@fomichev.me Signed-off-by: Jakub Kicinski

ipv6: adopt skb_dst_dev() and skb_dst_dev_net[_rcu]() helpers

2025-07-02T21:32:30+00:00

Use the new helpers as a step to deal with potential dst->dev races. v2: fix typo in ipv6_rthdr_rcv() (kernel test robot ) Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250630121934.3399505-10-edumazet@google.com Signed-off-by: Jakub Kicinski

netfilter: bridge: Move specific fragmented packet to slow_path instead of dropping it

2025-05-05T11:13:08+00:00

The config NF_CONNTRACK_BRIDGE will change the bridge forwarding for fragmented packets. The original bridge does not know that it is a fragmented packet and forwards it directly, after NF_CONNTRACK_BRIDGE is enabled, function nf_br_ip_fragment and br_ip6_fragment will check the headroom. In original br_forward, insufficient headroom of skb may indeed exist, but there's still a way to save the skb in the device driver after dev_queue_xmit.So droping the skb will change the original bridge forwarding in some cases. Fixes: 3c171f496ef5 ("netfilter: bridge: add connection tracking system") Signed-off-by: Huajian Yang Reviewed-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2024-06-13T20:13:46+00:00

Cross-merge networking fixes after downstream PR. No conflicts, no adjacent changes. Signed-off-by: Jakub Kicinski

netfilter: Use flowlabel flow key when re-routing mangled packets

2024-06-11T16:46:04+00:00

'ip6 dscp set $v' in an nftables outpute route chain has no effect. While nftables does detect the dscp change and calls the reroute hook. But ip6_route_me_harder never sets the dscp/flowlabel: flowlabel/dsfield routing rules are ignored and no reroute takes place. Thanks to Yi Chen for an excellent reproducer script that I used to validate this change. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Yi Chen Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso

net: Rename mono_delivery_time to tstamp_type for scalabilty

2024-05-23T21:14:23+00:00

mono_delivery_time was added to check if skb->tstamp has delivery time in mono clock base (i.e. EDT) otherwise skb->tstamp has timestamp in ingress and delivery_time at egress. Renaming the bitfield from mono_delivery_time to tstamp_type is for extensibilty for other timestamps such as userspace timestamp (i.e. SO_TXTIME) set via sock opts. As we are renaming the mono_delivery_time to tstamp_type, it makes sense to start assigning tstamp_type based on enum defined in this commit. Earlier we used bool arg flag to check if the tstamp is mono in function skb_set_delivery_time, Now the signature of the functions accepts tstamp_type to distinguish between mono and real time. Also skb_set_delivery_type_by_clockid is a new function which accepts clockid to determine the tstamp_type. In future tstamp_type:1 can be extended to support userspace timestamp by increasing the bitfield. Signed-off-by: Abhishek Chauhan Reviewed-by: Willem de Bruijn Reviewed-by: Martin KaFai Lau Link: https://lore.kernel.org/r/20240509211834.3235191-2-quic_abchauha@quicinc.com Signed-off-by: Martin KaFai Lau

xfrm: pass struct net to xfrm_decode_session wrappers

2023-10-06T06:31:53+00:00

Preparation patch, extra arg is not used. No functional changes intended. This is needed to replace the xfrm session decode functions with the flow dissector. skb_flow_dissect() cannot be used as-is, because it attempts to deduce the 'struct net' to use for bpf program fetch from skb->sk or skb->dev, but xfrm code path can see skbs that have neither sk or dev filled in. So either flow dissector needs to try harder, e.g. by also trying skb->dst->dev, or we have to pass the struct net explicitly. Passing the struct net doesn't look too bad to me, most places already have it available or can derive it from the output device. Reported-by: kernel test robot Link: https://lore.kernel.org/netdev/202309271628.27fd2187-oliver.sang@intel.com/ Signed-off-by: Florian Westphal Reviewed-by: Simon Horman Signed-off-by: Steffen Klassert

netfilter: Use l3mdev flow key when re-routing mangled packets

2022-05-16T11:03:29+00:00

Commit 40867d74c374 ("net: Add l3mdev index to flow struct and avoid oif reset for port devices") introduces a flow key specific for layer 3 domains, such as a VRF master device. This allows for explicit VRF domain selection instead of abusing the oif flow key. Update ip[6]_route_me_harder() to make use of that new key when re-routing mangled packets within VRFs instead of setting the flow oif, making it consistent with other users. Signed-off-by: Martin Willi Reviewed-by: David Ahern Signed-off-by: Pablo Neira Ayuso

netfilter: Update ip6_route_me_harder to consider L3 domain

2022-04-25T09:09:20+00:00

The commit referenced below fixed packet re-routing if Netfilter mangles a routing key property of a packet and the packet is routed in a VRF L3 domain. The fix, however, addressed IPv4 re-routing, only. This commit applies the same behavior for IPv6. While at it, untangle the nested ternary operator to make the code more readable. Fixes: 6d8b49c3a3a3 ("netfilter: Update ip_route_me_harder to consider L3 domain") Cc: stable@vger.kernel.org Signed-off-by: Martin Willi Reviewed-by: David Ahern Signed-off-by: Pablo Neira Ayuso

net: Add skb->mono_delivery_time to distinguish mono delivery_time from (rcv) timestamp

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

skb->tstamp was first used as the (rcv) timestamp. The major usage is to report it to the user (e.g. SO_TIMESTAMP). Later, skb->tstamp is also set as the (future) delivery_time (e.g. EDT in TCP) during egress and used by the qdisc (e.g. sch_fq) to make decision on when the skb can be passed to the dev. Currently, there is no way to tell skb->tstamp having the (rcv) timestamp or the delivery_time, so it is always reset to 0 whenever forwarded between egress and ingress. While it makes sense to always clear the (rcv) timestamp in skb->tstamp to avoid confusing sch_fq that expects the delivery_time, it is a performance issue [0] to clear the delivery_time if the skb finally egress to a fq@phy-dev. For example, when forwarding from egress to ingress and then finally back to egress: tcp-sender => veth@netns => veth@hostns => fq@eth0@hostns ^ ^ reset rest This patch adds one bit skb->mono_delivery_time to flag the skb->tstamp is storing the mono delivery_time (EDT) instead of the (rcv) timestamp. The current use case is to keep the TCP mono delivery_time (EDT) and to be used with sch_fq. A latter patch will also allow tc-bpf@ingress to read and change the mono delivery_time. In the future, another bit (e.g. skb->user_delivery_time) can be added for the SCM_TXTIME where the clock base is tracked by sk->sk_clockid. [ This patch is a prep work. The following patches will get the other parts of the stack ready first. Then another patch after that will finally set the skb->mono_delivery_time. ] skb_set_delivery_time() function is added. It is used by the tcp_output.c and during ip[6] fragmentation to assign the delivery_time to the skb->tstamp and also set the skb->mono_delivery_time. A note on the change in ip_send_unicast_reply() in ip_output.c. It is only used by TCP to send reset/ack out of a ctl_sk. Like the new skb_set_delivery_time(), this patch sets the skb->mono_delivery_time to 0 for now as a place holder. It will be enabled in a latter patch. A similar case in tcp_ipv6 can be done with skb_set_delivery_time() in tcp_v6_send_response(). [0] (slide 22): https://linuxplumbersconf.org/event/11/contributions/953/attachments/867/1658/LPC_2021_BPF_Datapath_Extensions.pdf Signed-off-by: Martin KaFai Lau Signed-off-by: David S. Miller