Before commit 40867d74c3 ("net: Add l3mdev index to flow struct and
avoid oif reset for port devices") it was possible to use FIB rules to
match on a L3 domain. This was done by having a FIB rule match on iif /
oif being a L3 master device. It worked because prior to the FIB rule
lookup the iif / oif fields in the flow structure were reset to the
index of the L3 master device to which the input / output device was
enslaved to.
The above scheme made it impossible to match on the original input /
output device. Therefore, cited commit stopped overwriting the iif / oif
fields in the flow structure and instead stored the index of the
enslaving L3 master device in a new field ('flowi_l3mdev') in the flow
structure.
While the change enabled new use cases, it broke the original use case
of matching on a L3 domain. Fix this by interpreting the iif / oif
matching on a L3 master device as a match against the L3 domain. In
other words, if the iif / oif in the FIB rule points to a L3 master
device, compare the provided index against 'flowi_l3mdev' rather than
'flowi_{i,o}if'.
Before cited commit, a FIB rule that matched on 'iif vrf1' would only
match incoming traffic from devices enslaved to 'vrf1'. With the
proposed change (i.e., comparing against 'flowi_l3mdev'), the rule would
also match traffic originating from a socket bound to 'vrf1'. Avoid that
by adding a new flow flag ('FLOWI_FLAG_L3MDEV_OIF') that indicates if
the L3 domain was derived from the output interface or the input
interface (when not set) and take this flag into account when evaluating
the FIB rule against the flow structure.
Avoid unnecessary checks in the data path by detecting that a rule
matches on a L3 master device when the rule is installed and marking it
as such.
Tested using the following script [1].
Output before 40867d74c3 (v5.4.291):
default dev dummy1 table 100 scope link
default dev dummy1 table 200 scope link
Output after 40867d74c3:
default dev dummy1 table 300 scope link
default dev dummy1 table 300 scope link
Output with this patch:
default dev dummy1 table 100 scope link
default dev dummy1 table 200 scope link
[1]
#!/bin/bash
ip link add name vrf1 up type vrf table 10
ip link add name dummy1 up master vrf1 type dummy
sysctl -wq net.ipv4.conf.all.forwarding=1
sysctl -wq net.ipv4.conf.all.rp_filter=0
ip route add table 100 default dev dummy1
ip route add table 200 default dev dummy1
ip route add table 300 default dev dummy1
ip rule add prio 0 oif vrf1 table 100
ip rule add prio 1 iif vrf1 table 200
ip rule add prio 2 table 300
ip route get 192.0.2.1 oif dummy1 fibmatch
ip route get 192.0.2.1 iif dummy1 from 198.51.100.1 fibmatch
Fixes: 40867d74c3 ("net: Add l3mdev index to flow struct and avoid oif reset for port devices")
Reported-by: hanhuihui <hanhuihui5@huawei.com>
Closes: https://lore.kernel.org/netdev/ec671c4f821a4d63904d0da15d604b75@huawei.com/
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20250414172022.242991-2-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add an attribute that allows matching on DSCP with a mask. Matching on
DSCP with a mask is needed in deployments where users encode path
information into certain bits of the DSCP field.
Temporarily set the type of the attribute to 'NLA_REJECT' while support
is being added.
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Link: https://patch.msgid.link/20250220080525.831924-2-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add attributes that allow matching on source and destination ports with
a mask. Matching on the source port with a mask is needed in deployments
where users encode path information into certain bits of the UDP source
port.
Temporarily set the type of the attributes to 'NLA_REJECT' while support
is being added.
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20250217134109.311176-2-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
fib_nl_delrule() is the doit() handler for RTM_DELRULE but also called
from vrf_newlink() in case something fails in vrf_add_fib_rules().
In the latter case, RTNL is already held and the 4th arg is true.
Let's hold per-netns RTNL in fib_delrule() if rtnl_held is false.
Now we can place ASSERT_RTNL_NET() in call_fib_rule_notifiers().
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Tested-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20250207072502.87775-9-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
fib_nl_newrule() is the doit() handler for RTM_NEWRULE but also called
from vrf_newlink().
In the latter case, RTNL is already held and the 4th arg is true.
Let's hold per-netns RTNL in fib_newrule() if rtnl_held is false.
Note that we call fib_rule_get() before releasing per-netns RTNL to call
notify_rule_change() without RTNL and prevent freeing the new rule.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Tested-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20250207072502.87775-7-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
fib_nl_newrule() / fib_nl_delrule() is the doit() handler for
RTM_NEWRULE / RTM_DELRULE but also called from vrf_newlink().
Currently, we hold RTNL on both paths but will not on the former.
Also, we set dev_net(dev)->rtnl to skb->sk in vrf_fib_rule() because
fib_nl_newrule() / fib_nl_delrule() fetch net as sock_net(skb->sk).
Let's Factorise the two functions and pass net and rtnl_held flag.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Tested-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20250207072502.87775-6-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
fib_nl_newrule() / fib_nl_delrule() looks up struct fib_rules_ops
in sock_net(skb->sk) and calls rule_exists() / rule_find() respectively.
fib_nl_newrule() creates a new rule and links it to the found ops, so
struct fib_rule never belongs to a different netns's ops->rules_list.
Let's remove redundant netns check in rule_exists() and rule_find().
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Tested-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20250207072502.87775-2-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Now that both IPv4 and IPv6 correctly handle the new flow label
attributes, enable user space to configure FIB rules that make use of
the flow label by changing the policy to stop rejecting them and
accepting 32 bit values in big-endian byte order.
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Add new FIB rule attributes which will allow user space to match on the
IPv6 flow label with a mask. Temporarily set the type of the attributes
to 'NLA_REJECT' while support is being added in the IPv6 code.
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Most of the original conversion is from the spatch below,
but I edited some and left out other instances that were
either buggy after conversion (where default values don't
fit into the type) or just looked strange.
@@
expression attr, def;
expression val;
identifier fn =~ "^nla_get_.*";
fresh identifier dfn = fn ## "_default";
@@
(
-if (attr)
- val = fn(attr);
-else
- val = def;
+val = dfn(attr, def);
|
-if (!attr)
- val = def;
-else
- val = fn(attr);
+val = dfn(attr, def);
|
-if (!attr)
- return def;
-return fn(attr);
+return dfn(attr, def);
|
-attr ? fn(attr) : def
+dfn(attr, def)
|
-!attr ? def : fn(attr)
+dfn(attr, def)
)
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@kernel.org>
Link: https://patch.msgid.link/20241108114145.0580b8684e7f.I740beeaa2f70ebfc19bfca1045a24d6151992790@changeid
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We will remove rtnl_register() in favour of rtnl_register_many().
When it succeeds, rtnl_register_many() guarantees all rtnetlink types
in the passed array are supported, and there is no chance that a part
of message types is not supported.
Let's use rtnl_register_many() instead.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20241014201828.91221-7-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Now that both IPv4 and IPv6 support the new DSCP selector, enable user
space to configure FIB rules that make use of it by changing the policy
of the new DSCP attribute so that it accepts values in the range of [0,
63].
Use NLA_U8 rather than NLA_UINT as the field is of fixed size.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20240911093748.3662015-5-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The FIB rule TOS selector is implemented differently between IPv4 and
IPv6. In IPv4 it is used to match on the three "Type of Services" bits
specified in RFC 791, while in IPv6 is it is used to match on the six
DSCP bits specified in RFC 2474.
Add a new FIB rule attribute to allow matching on DSCP. The attribute
will be used to implement a 'dscp' selector in ip-rule with a consistent
behavior between IPv4 and IPv6.
For now, set the type of the attribute to 'NLA_REJECT' so that user
space will not be able to configure it. This restriction will be lifted
once both IPv4 and IPv6 support the new attribute.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20240911093748.3662015-2-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
