linux.git/net/core/rtnetlink.c, branch v6.11

rtnetlink: Don't ignore IFLA_TARGET_NETNSID when ifname is specified in rtnl_dellink().

2024-07-29T10:36:48+00:00

The cited commit accidentally replaced tgt_net with net in rtnl_dellink().

As a result, IFLA_TARGET_NETNSID is ignored if the interface is specified
with IFLA_IFNAME or IFLA_ALT_IFNAME.

Let's pass tgt_net to rtnl_dev_get().

Fixes: cc6090e985d7 ("net: rtnetlink: introduce helper to get net_device instance by ifname")
Signed-off-by: Kuniyuki Iwashima 
Reviewed-by: Jakub Kicinski 
Signed-off-by: David S. Miller

net: reduce rtnetlink_rcv_msg() stack usage

2024-07-12T00:13:58+00:00

IFLA_MAX is increasing slowly but surely.

Some compilers use more than 512 bytes of stack in rtnetlink_rcv_msg()
because it calls rtnl_calcit() for RTM_GETLINK message.

Use noinline_for_stack attribute to not inline rtnl_calcit(),
and directly use nla_for_each_attr_type() (Jakub suggestion)
because we only care about IFLA_EXT_MASK at this stage.

Signed-off-by: Eric Dumazet 
Reviewed-by: Simon Horman 
Link: https://patch.msgid.link/20240710151653.3786604-1-edumazet@google.com
Signed-off-by: Jakub Kicinski

rtnetlink: move rtnl_lock handling out of af_netlink

2024-06-10T12:15:40+00:00

Now that we have an intermediate layer of code for handling
rtnl-level netlink dump quirks, we can move the rtnl_lock
taking there.

For dump handlers with RTNL_FLAG_DUMP_SPLIT_NLM_DONE we can
avoid taking rtnl_lock just to generate NLM_DONE, once again.

Signed-off-by: Jakub Kicinski 
Reviewed-by: Kuniyuki Iwashima 
Reviewed-by: Eric Dumazet 
Signed-off-by: David S. Miller

rtnetlink: make the "split" NLM_DONE handling generic

2024-06-05T11:34:54+00:00

Jaroslav reports Dell's OMSA Systems Management Data Engine
expects NLM_DONE in a separate recvmsg(), both for rtnl_dump_ifinfo()
and inet_dump_ifaddr(). We already added a similar fix previously in
commit 460b0d33cf10 ("inet: bring NLM_DONE out to a separate recv() again")

Instead of modifying all the dump handlers, and making them look
different than modern for_each_netdev_dump()-based dump handlers -
put the workaround in rtnetlink code. This will also help us move
the custom rtnl-locking from af_netlink in the future (in net-next).

Note that this change is not touching rtnl_dump_all(). rtnl_dump_all()
is different kettle of fish and a potential problem. We now mix families
in a single recvmsg(), but NLM_DONE is not coalesced.

Tested:

  ./cli.py --dbg-small-recv 4096 --spec netlink/specs/rt_addr.yaml \
           --dump getaddr --json '{"ifa-family": 2}'

  ./cli.py --dbg-small-recv 4096 --spec netlink/specs/rt_route.yaml \
           --dump getroute --json '{"rtm-family": 2}'

  ./cli.py --dbg-small-recv 4096 --spec netlink/specs/rt_link.yaml \
           --dump getlink

Fixes: 3e41af90767d ("rtnetlink: use xarray iterator to implement rtnl_dump_ifinfo()")
Fixes: cdb2f80f1c10 ("inet: use xa_array iterator to implement inet_dump_ifaddr()")
Reported-by: Jaroslav Pulchart 
Link: https://lore.kernel.org/all/CAK8fFZ7MKoFSEzMBDAOjoUt+vTZRRQgLDNXEOfdCCXSoXXKE0g@mail.gmail.com
Signed-off-by: Jakub Kicinski 
Reviewed-by: Eric Dumazet 
Signed-off-by: David S. Miller

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

2024-05-09T17:01:01+00:00

Cross-merge networking fixes after downstream PR.

No conflicts.

Adjacent changes:

drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c
  35d92abfbad8 ("net: hns3: fix kernel crash when devlink reload during initialization")
  2a1a1a7b5fd7 ("net: hns3: add command queue trace for hns3")

Signed-off-by: Jakub Kicinski

rtnetlink: allow rtnl_fill_link_netnsid() to run under RCU protection

2024-05-07T09:14:50+00:00

We want to be able to run rtnl_fill_ifinfo() under RCU protection
instead of RTNL in the future.

All rtnl_link_ops->get_link_net() methods already using dev_net()
are ready. I added READ_ONCE() annotations on others.

Signed-off-by: Eric Dumazet 
Reviewed-by: Simon Horman 
Signed-off-by: Paolo Abeni

rtnetlink: do not depend on RTNL in rtnl_xdp_prog_skb()

2024-05-07T09:14:50+00:00

dev->xdp_prog is protected by RCU, we can lift RTNL requirement
from rtnl_xdp_prog_skb().

Signed-off-by: Eric Dumazet 
Reviewed-by: Simon Horman 
Signed-off-by: Paolo Abeni

rtnetlink: do not depend on RTNL in rtnl_fill_proto_down()

2024-05-07T09:14:50+00:00

Change dev_change_proto_down() and dev_change_proto_down_reason()
to write once on dev->proto_down and dev->proto_down_reason.

Then rtnl_fill_proto_down() can use READ_ONCE() annotations
and run locklessly.

rtnl_proto_down_size() should assume worst case,
because readng dev->proto_down_reason multiple
times would be racy without RTNL in the future.

Signed-off-by: Eric Dumazet 
Reviewed-by: Simon Horman 
Signed-off-by: Paolo Abeni

rtnetlink: do not depend on RTNL for many attributes

2024-05-07T09:14:50+00:00

Following device fields can be read locklessly
in rtnl_fill_ifinfo() :

type, ifindex, operstate, link_mode, mtu, min_mtu, max_mtu, group,
promiscuity, allmulti, num_tx_queues, gso_max_segs, gso_max_size,
gro_max_size, gso_ipv4_max_size, gro_ipv4_max_size, tso_max_size,
tso_max_segs, num_rx_queues.

Signed-off-by: Eric Dumazet 
Signed-off-by: Paolo Abeni

rtnetlink: do not depend on RTNL for IFLA_TXQLEN output

2024-05-07T09:14:50+00:00

rtnl_fill_ifinfo() can read dev->tx_queue_len locklessly,
granted we add corresponding READ_ONCE()/WRITE_ONCE() annotations.

Add missing READ_ONCE(dev->tx_queue_len) in teql_enqueue()

Signed-off-by: Eric Dumazet 
Signed-off-by: Paolo Abeni