kernel/linux.git/include/net/route.h, branch v6.12.80

net: use dst_dev_rcu() in sk_setup_caps()

2026-01-08T09:15:01+00:00

[ Upstream commit 99a2ace61b211b0be861b07fbaa062fca4b58879 ] Use RCU to protect accesses to dst->dev from sk_setup_caps() and sk_dst_gso_max_size(). Also use dst_dev_rcu() in ip6_dst_mtu_maybe_forward(), and ip_dst_mtu_maybe_forward(). ip4_dst_hoplimit() can use dst_dev_net_rcu(). Fixes: 4a6ce2b6f2ec ("net: introduce a new function dst_dev_put()") Signed-off-by: Eric Dumazet Reviewed-by: David Ahern Link: https://patch.msgid.link/20250828195823.3958522-6-edumazet@google.com Signed-off-by: Jakub Kicinski [Harshit: Backport to 6.12.y, resolve conflict due to missing commit: 22d6c9eebf2e ("net: Unexport shared functions for DCCP.") in 6.12.y] Signed-off-by: Harshit Mogalapalli Signed-off-by: Greg Kroah-Hartman

ipv4: adopt dst_dev, skb_dst_dev and skb_dst_dev_net[_rcu]

2025-10-23T14:20:45+00:00

[ Upstream commit a74fc62eec155ca5a6da8ff3856f3dc87fe24558 ] Use the new helpers as a first step to deal with potential dst->dev races. Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250630121934.3399505-8-edumazet@google.com Signed-off-by: Jakub Kicinski Stable-dep-of: 833d4313bc1e ("mptcp: reset blackhole on success with non-loopback ifaces") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

ipv4: Convert ip_route_input() to dscp_t.

2025-03-07T17:25:29+00:00

[ Upstream commit 7e863e5db6185b1add0df4cb01b31a4ed1c4b738 ] 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 Stable-dep-of: 27843ce6ba3d ("ipvlan: ensure network headers are in skb linear part") Signed-off-by: Sasha Levin

ipv4: add RCU protection to ip4_dst_hoplimit()

2025-02-21T13:01:40+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

xfrm: Unmask upper DSCP bits in xfrm_get_tos()

2024-08-31T16:44:51+00:00

The function returns a value that is used to initialize 'flowi4_tos' before being passed to the FIB lookup API in the following call chain: xfrm_bundle_create() tos = xfrm_get_tos(fl, family) xfrm_dst_lookup(..., tos, ...) __xfrm_dst_lookup(..., tos, ...) xfrm4_dst_lookup(..., tos, ...) __xfrm4_dst_lookup(..., tos, ...) fl4->flowi4_tos = tos __ip_route_output_key(net, fl4) Unmask the upper DSCP bits so that in the future the output route lookup could be performed according to the full DSCP value. Remove IPTOS_RT_MASK since it is no longer used. Signed-off-by: Ido Schimmel Reviewed-by: Guillaume Nault Signed-off-by: David S. Miller

ipv4: Unmask upper DSCP bits in ip_sock_rt_tos()

2024-08-31T16:44:51+00:00

The function is used to read the DS field that was stored in IPv4 sockets via the IP_TOS socket option so that it could be used to initialize the flowi4_tos field before resolving an output route. Unmask the upper DSCP bits so that in the future the output route lookup could be performed according to the full DSCP value. Signed-off-by: Ido Schimmel Reviewed-by: Guillaume Nault Signed-off-by: David S. Miller

inet: introduce dst_rtable() helper

2024-05-01T01:32:38+00:00

I added dst_rt6_info() in commit e8dfd42c17fa ("ipv6: introduce dst_rt6_info() helper") This patch does a similar change for IPv4. Instead of (struct rtable *)dst casts, we can use : #define dst_rtable(_ptr) \ container_of_const(_ptr, struct rtable, dst) Patch is smaller than IPv6 one, because IPv4 has skb_rtable() helper. Signed-off-by: Eric Dumazet Reviewed-by: David Ahern Reviewed-by: Sabrina Dubroca Link: https://lore.kernel.org/r/20240429133009.1227754-1-edumazet@google.com Signed-off-by: Jakub Kicinski

ipv4: Remove RTO_ONLINK.

2024-04-12T02:52:11+00:00

RTO_ONLINK was a flag used in ->flowi4_tos that allowed to alter the scope of an IPv4 route lookup. Setting this flag was equivalent to specifying RT_SCOPE_LINK in ->flowi4_scope. With commit ec20b2830093 ("ipv4: Set scope explicitly in ip_route_output()."), the last users of RTO_ONLINK have been removed. Therefore, we can now drop the code that checked this bit and stop modifying ->flowi4_scope in ip_route_output_key_hash(). Signed-off-by: Guillaume Nault Reviewed-by: Przemek Kitszel Reviewed-by: David Ahern Link: https://lore.kernel.org/r/57de760565cab55df7b129f523530ac6475865b2.1712754146.git.gnault@redhat.com Signed-off-by: Jakub Kicinski

ipv4: Set scope explicitly in ip_route_output().

2024-04-08T12:20:51+00:00

Add a "scope" parameter to ip_route_output() so that callers don't have to override the tos parameter with the RTO_ONLINK flag if they want a local scope. This will allow converting flowi4_tos to dscp_t in the future, thus allowing static analysers to flag invalid interactions between "tos" (the DSCP bits) and ECN. Only three users ask for local scope (bonding, arp and atm). The others continue to use RT_SCOPE_UNIVERSE. While there, add a comment to warn users about the limitations of ip_route_output(). Signed-off-by: Guillaume Nault Acked-by: Leon Romanovsky # infiniband Signed-off-by: David S. Miller

ipv4: Set the routing scope properly in ip_route_output_ports().

2024-02-13T01:33:05+00:00

Set scope automatically in ip_route_output_ports() (using the socket SOCK_LOCALROUTE flag). This way, callers don't have to overload the tos with the RTO_ONLINK flag, like RT_CONN_FLAGS() does. For callers that don't pass a struct sock, this doesn't change anything as the scope is still set to RT_SCOPE_UNIVERSE when sk is NULL. Callers that passed a struct sock and used RT_CONN_FLAGS(sk) or RT_CONN_FLAGS_TOS(sk, tos) for the tos are modified to use ip_sock_tos(sk) and RT_TOS(tos) respectively, as overloading tos with the RTO_ONLINK flag now becomes unnecessary. In drivers/net/amt.c, all ip_route_output_ports() calls use a 0 tos parameter, ignoring the SOCK_LOCALROUTE flag of the socket. But the sk parameter is a kernel socket, which doesn't have any configuration path for setting SOCK_LOCALROUTE anyway. Therefore, ip_route_output_ports() will continue to initialise scope with RT_SCOPE_UNIVERSE and amt.c doesn't need to be modified. Also, remove RT_CONN_FLAGS() and RT_CONN_FLAGS_TOS() from route.h as these macros are now unused. The objective is to eventually remove RTO_ONLINK entirely to allow converting ->flowi4_tos to dscp_t. This will ensure proper isolation between the DSCP and ECN bits, thus minimising the risk of introducing bugs where TOS values interfere with ECN. Signed-off-by: Guillaume Nault Reviewed-by: David Ahern Link: https://lore.kernel.org/r/dacfd2ab40685e20959ab7b53c427595ba229e7d.1707496938.git.gnault@redhat.com Signed-off-by: Jakub Kicinski