linux-stable.git/include/net/route.h, branch linux-6.13.y

ipv4: add RCU protection to ip4_dst_hoplimit()

2025-02-21T13:11:14+00:00

[ Upstream commit 469308552ca4560176cfc100e7ca84add1bebd7c ]

ip4_dst_hoplimit() must use RCU protection to make
sure the net structure it reads does not disappear.

Fixes: fa50d974d104 ("ipv4: Namespaceify ip_default_ttl sysctl knob")
Signed-off-by: Eric Dumazet 
Reviewed-by: Kuniyuki Iwashima 
Link: https://patch.msgid.link/20250205155120.1676781-3-edumazet@google.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

net: ip: make ip_route_use_hint() return drop reasons

2024-11-12T10:24:51+00:00

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() return drop reasons

2024-11-12T10:24:51+00:00

In this commit, we make ip_route_input() return skb drop reasons that come
from ip_route_input_noref().

Meanwhile, adjust all the call to it.

Signed-off-by: Menglong Dong 
Signed-off-by: Paolo Abeni

net: ip: make ip_route_input_noref() return drop reasons

2024-11-12T10:24:51+00:00

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 ip_mc_validate_source() return drop reason

2024-11-12T10:24:50+00:00

Make ip_mc_validate_source() return drop reason, and adjust the call of
it in ip_route_input_mc().

Another caller of it is ip_rcv_finish_core->udp_v4_early_demux, and the
errno is not checked in detail, so we don't do more adjustment for it.

The drop reason "SKB_DROP_REASON_IP_LOCALNET" is added in this commit.

Signed-off-by: Menglong Dong 
Signed-off-by: Paolo Abeni

ipv4: Prepare ip_route_output() to future .flowi4_tos conversion.

2024-11-08T04:33:19+00:00

Convert the "tos" parameter of ip_route_output() to dscp_t. This way
we'll have a dscp_t value directly available when .flowi4_tos will
eventually be converted to dscp_t.

All ip_route_output() callers but one set this "tos" parameter to 0 and
therefore don't need to be adapted to the new prototype.

Only br_nf_pre_routing_finish() needs conversion. It can just use
ip4h_dscp() to get the DSCP field from the IPv4 header.

Signed-off-by: Guillaume Nault 
Reviewed-by: Ido Schimmel 
Link: https://patch.msgid.link/0f10d031dd44c70aae9bc6e19391cb30d5c2fe71.1730928699.git.gnault@redhat.com
Signed-off-by: Jakub Kicinski

ipv4: Convert ip_mc_validate_source() to dscp_t.

2024-10-10T00:31:40+00:00

Pass a dscp_t variable to ip_mc_validate_source(), instead of a plain
u8, to prevent accidental setting of ECN bits in ->flowi4_tos.

Callers of ip_mc_validate_source() to consider are:

  * ip_route_input_mc() which already has a dscp_t variable to pass as
    parameter. We just need to remove the inet_dscp_to_dsfield()
    conversion.

  * udp_v4_early_demux() which gets the DSCP directly from the IPv4
    header and can simply use the ip4h_dscp() helper.

Also, stop including net/inet_dscp.h in udp.c as we don't use any of
its declarations anymore.

Signed-off-by: Guillaume Nault 
Reviewed-by: Ido Schimmel 
Tested-by: Ido Schimmel 
Reviewed-by: David Ahern 
Link: https://patch.msgid.link/c91b2cca04718b7ee6cf5b9c1d5b40507d65a8d4.1728302212.git.gnault@redhat.com
Signed-off-by: Jakub Kicinski

ipv4: Convert ip_route_use_hint() to dscp_t.

2024-10-10T00:31:40+00:00

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.

2024-10-03T23:21:21+00:00

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

ipv4: Convert ip_route_input() to dscp_t.

2024-10-03T23:21:21+00:00

Pass a dscp_t variable to ip_route_input(), instead of a plain u8, to
prevent accidental setting of ECN bits in ->flowi4_tos.

Callers of ip_route_input() to consider are:

  * input_action_end_dx4_finish() and input_action_end_dt4() in
    net/ipv6/seg6_local.c. These functions set the tos parameter to 0,
    which is already a valid dscp_t value, so they don't need to be
    adjusted for the new prototype.

  * icmp_route_lookup(), which already has a dscp_t variable to pass as
    parameter. We just need to remove the inet_dscp_to_dsfield()
    conversion.

  * br_nf_pre_routing_finish(), ip_options_rcv_srr() and ip4ip6_err(),
    which get the DSCP directly from IPv4 headers. Define a helper to
    read the .tos field of struct iphdr as dscp_t, so that these
    function don't have to do the conversion manually.

While there, declare *iph as const in br_nf_pre_routing_finish(),
declare its local variables in reverse-christmas-tree order and move
the "err = ip_route_input()" assignment out of the conditional to avoid
checkpatch warning.

Signed-off-by: Guillaume Nault 
Reviewed-by: David Ahern 
Link: https://patch.msgid.link/e9d40781d64d3d69f4c79ac8a008b8d67a033e8d.1727807926.git.gnault@redhat.com
Signed-off-by: Jakub Kicinski