linux/net/ipv4/ip_input.c, branch v6.17

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

2025-07-04T06:03:18Z

Cross-merge networking fixes after downstream PR (net-6.16-rc5). No conflicts. No adjacent changes. Signed-off-by: Paolo Abeni

net: preserve MSG_ZEROCOPY with forwarding

2025-07-02T22:07:16Z

MSG_ZEROCOPY data must be copied before data is queued to local sockets, to avoid indefinite timeout until memory release. This test is performed by skb_orphan_frags_rx, which is called when looping an egress skb to packet sockets, error queue or ingress path. To preserve zerocopy for skbs that are looped to ingress but are then forwarded to an egress device rather than delivered locally, defer this last check until an skb enters the local IP receive path. This is analogous to existing behavior of skb_clear_delivery_time. Signed-off-by: Willem de Bruijn Link: https://patch.msgid.link/20250630194312.1571410-2-willemdebruijn.kernel@gmail.com Signed-off-by: Jakub Kicinski

net: ipv4: fix stat increase when udp early demux drops the packet

2025-07-02T21:46:44Z

udp_v4_early_demux now returns drop reasons as it either returns 0 or ip_mc_validate_source, which returns itself a drop reason. However its use was not converted in ip_rcv_finish_core and the drop reason is ignored, leading to potentially skipping increasing LINUX_MIB_IPRPFILTER if the drop reason is SKB_DROP_REASON_IP_RPFILTER. This is a fix and we're not converting udp_v4_early_demux to explicitly return a drop reason to ease backports; this can be done as a follow-up. Fixes: d46f827016d8 ("net: ip: make ip_mc_validate_source() return drop reason") Cc: Menglong Dong Reported-by: Sabrina Dubroca Signed-off-by: Antoine Tenart Reviewed-by: Sabrina Dubroca Link: https://patch.msgid.link/20250701074935.144134-1-atenart@kernel.org Signed-off-by: Jakub Kicinski

ipv4: remove useless arg

2025-01-03T01:17:40Z

The "struct sock *sk" parameter in ip_rcv_finish_core is unused, which leads the compiler to optimize it out. As a result, the "struct sk_buff *skb" parameter is passed using x1. And this make kprobe hard to use. Signed-off-by: Yu Tian Link: https://patch.msgid.link/20241231023610.1657926-1-tianyu2@kernelsoft.com Signed-off-by: Jakub Kicinski

net: ip: make ip_route_use_hint() return drop reasons

2024-11-12T10:24:51Z

In this commit, we make ip_route_use_hint() return drop reasons. The drop reasons that we return are similar to what we do in ip_route_input_slow(), and no drop reasons are added in this commit. Signed-off-by: Menglong Dong Signed-off-by: Paolo Abeni

net: ip: make ip_route_input_noref() return drop reasons

2024-11-12T10:24:51Z

In this commit, we make ip_route_input_noref() return drop reasons, which come from ip_route_input_rcu(). We need adjust the callers of ip_route_input_noref() to make sure the return value of ip_route_input_noref() is used properly. The errno that ip_route_input_noref() returns comes from ip_route_input and bpf_lwt_input_reroute in the origin logic, and we make them return -EINVAL on error instead. In the following patch, we will make ip_route_input() returns drop reasons too. Signed-off-by: Menglong Dong Signed-off-by: Paolo Abeni

net: ip: make fib_validate_source() support drop reasons

2024-11-12T10:24:50Z

In this commit, we make fib_validate_source() and __fib_validate_source() return -reason instead of errno on error. The return value of fib_validate_source can be -errno, 0, and 1. It's hard to make fib_validate_source() return drop reasons directly. The fib_validate_source() will return 1 if the scope of the source(revert) route is HOST. And the __mkroute_input() will mark the skb with IPSKB_DOREDIRECT in this case (combine with some other conditions). And then, a REDIRECT ICMP will be sent in ip_forward() if this flag exists. We can't pass this information to __mkroute_input if we make fib_validate_source() return drop reasons. Therefore, we introduce the wrapper fib_validate_source_reason() for fib_validate_source(), which will return the drop reasons on error. In the origin logic, LINUX_MIB_IPRPFILTER will be counted if fib_validate_source() return -EXDEV. And now, we need to adjust it by checking "reason == SKB_DROP_REASON_IP_RPFILTER". However, this will take effect only after the patch "net: ip: make ip_route_input_noref() return drop reasons", as we can't pass the drop reasons from fib_validate_source() to ip_rcv_finish_core() in this patch. Following new drop reasons are added in this patch: SKB_DROP_REASON_IP_LOCAL_SOURCE SKB_DROP_REASON_IP_INVALID_SOURCE Signed-off-by: Menglong Dong Signed-off-by: Paolo Abeni

ipv4: Convert ip_route_use_hint() to dscp_t.

2024-10-10T00:31:40Z

Pass a dscp_t variable to ip_route_use_hint(), instead of a plain u8, to prevent accidental setting of ECN bits in ->flowi4_tos. Only ip_rcv_finish_core() actually calls ip_route_use_hint(). Use the ip4h_dscp() helper to get the DSCP from the IPv4 header. While there, modify the declaration of ip_route_use_hint() in include/net/route.h so that it matches the prototype of its implementation in net/ipv4/route.c. Signed-off-by: Guillaume Nault Reviewed-by: Ido Schimmel Tested-by: Ido Schimmel Reviewed-by: David Ahern Link: https://patch.msgid.link/c40994fdf804db7a363d04fdee01bf48dddda676.1728302212.git.gnault@redhat.com Signed-off-by: Jakub Kicinski

ipv4: Convert ip_route_input_noref() to dscp_t.

2024-10-03T23:21:21Z

Pass a dscp_t variable to ip_route_input_noref(), instead of a plain u8, to prevent accidental setting of ECN bits in ->flowi4_tos. Callers of ip_route_input_noref() to consider are: * arp_process() in net/ipv4/arp.c. This function sets the tos parameter to 0, which is already a valid dscp_t value, so it doesn't need to be adjusted for the new prototype. * ip_route_input(), which already has a dscp_t variable to pass as parameter. We just need to remove the inet_dscp_to_dsfield() conversion. * ipvlan_l3_rcv(), bpf_lwt_input_reroute(), ip_expire(), ip_rcv_finish_core(), xfrm4_rcv_encap_finish() and xfrm4_rcv_encap(), which get the DSCP directly from IPv4 headers and can simply use the ip4h_dscp() helper. While there, declare the IPv4 header pointers as const in ipvlan_l3_rcv() and bpf_lwt_input_reroute(). Also, modify the declaration of ip_route_input_noref() in include/net/route.h so that it matches the prototype of its implementation in net/ipv4/route.c. Signed-off-by: Guillaume Nault Reviewed-by: David Ahern Link: https://patch.msgid.link/a8a747bed452519c4d0cc06af32c7e7795d7b627.1727807926.git.gnault@redhat.com Signed-off-by: Jakub Kicinski

net/ipv4: make use of the helper macro LIST_HEAD()

2024-09-07T01:10:21Z

list_head can be initialized automatically with LIST_HEAD() instead of calling INIT_LIST_HEAD(). Here we can simplify the code. Signed-off-by: Hongbo Li Link: https://patch.msgid.link/20240904093243.3345012-2-lihongbo22@huawei.com Signed-off-by: Jakub Kicinski