linux.git/net/core/rtnetlink.c, branch v5.15

rtnetlink: fix if_nlmsg_stats_size() under estimation

2021-10-06T14:09:46+00:00

rtnl_fill_statsinfo() is filling skb with one mandatory if_stats_msg structure.

nlmsg_put(skb, pid, seq, type, sizeof(struct if_stats_msg), flags);

But if_nlmsg_stats_size() never considered the needed storage.

This bug did not show up because alloc_skb(X) allocates skb with
extra tailroom, because of added alignments. This could very well
be changed in the future to have deterministic behavior.

Fixes: 10c9ead9f3c6 ("rtnetlink: add new RTM_GETSTATS message to dump link stats")
Signed-off-by: Eric Dumazet 
Cc: Roopa Prabhu 
Acked-by: Roopa Prabhu 
Signed-off-by: David S. Miller

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

2021-08-27T00:57:57+00:00

drivers/net/wwan/mhi_wwan_mbim.c - drop the extra arg.

Signed-off-by: Jakub Kicinski

rtnetlink: Return correct error on changing device netns

2021-08-26T11:08:08+00:00

Currently when device is moved between network namespaces using
RTM_NEWLINK message type and one of netns attributes (FLA_NET_NS_PID,
IFLA_NET_NS_FD, IFLA_TARGET_NETNSID) but w/o specifying IFLA_IFNAME, and
target namespace already has device with same name, userspace will get
EINVAL what is confusing and makes debugging harder.

Fix it so that userspace gets more appropriate EEXIST instead what makes
debugging much easier.

Before:

  # ./ifname.sh
  + ip netns add ns0
  + ip netns exec ns0 ip link add l0 type dummy
  + ip netns exec ns0 ip link show l0
  8: l0:  mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
      link/ether 66:90:b5:d5:78:69 brd ff:ff:ff:ff:ff:ff
  + ip link add l0 type dummy
  + ip link show l0
  10: l0:  mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
      link/ether 6e:c6:1f:15:20:8d brd ff:ff:ff:ff:ff:ff
  + ip link set l0 netns ns0
  RTNETLINK answers: Invalid argument

After:

  # ./ifname.sh
  + ip netns add ns0
  + ip netns exec ns0 ip link add l0 type dummy
  + ip netns exec ns0 ip link show l0
  8: l0:  mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
      link/ether 1e:4a:72:e3:e3:8f brd ff:ff:ff:ff:ff:ff
  + ip link add l0 type dummy
  + ip link show l0
  10: l0:  mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
      link/ether f2:fc:fe:2b:7d:a6 brd ff:ff:ff:ff:ff:ff
  + ip link set l0 netns ns0
  RTNETLINK answers: File exists

The problem is that do_setlink() passes its `char *ifname` argument,
that it gets from a caller, to __dev_change_net_namespace() as is (as
`const char *pat`), but semantics of ifname and pat can be different.

For example, __rtnl_newlink() does this:

net/core/rtnetlink.c
    3270	char ifname[IFNAMSIZ];
     ...
    3286	if (tb[IFLA_IFNAME])
    3287		nla_strscpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
    3288	else
    3289		ifname[0] = '\0';
     ...
    3364	if (dev) {
     ...
    3394		return do_setlink(skb, dev, ifm, extack, tb, ifname, status);
    3395	}

, i.e. do_setlink() gets ifname pointer that is always valid no matter
if user specified IFLA_IFNAME or not and then do_setlink() passes this
ifname pointer as is to __dev_change_net_namespace() as pat argument.

But the pat (pattern) in __dev_change_net_namespace() is used as:

net/core/dev.c
   11198	err = -EEXIST;
   11199	if (__dev_get_by_name(net, dev->name)) {
   11200		/* We get here if we can't use the current device name */
   11201		if (!pat)
   11202			goto out;
   11203		err = dev_get_valid_name(net, dev, pat);
   11204		if (err < 0)
   11205			goto out;
   11206	}

As the result the `goto out` path on line 11202 is neven taken and
instead of returning EEXIST defined on line 11198,
__dev_change_net_namespace() returns an error from dev_get_valid_name()
and this, in turn, will be EINVAL for ifname[0] = '\0' set earlier.

Fixes: d8a5ec672768 ("[NET]: netlink support for moving devices between network namespaces.")
Signed-off-by: Andrey Ignatov 
Signed-off-by: David S. Miller

net: Support filtering interfaces on no master

2021-08-10T23:03:34+00:00

Currently there's support for filtering neighbours/links for interfaces
which have a specific master device (using the IFLA_MASTER/NDA_MASTER
attributes).

This patch adds support for filtering interfaces/neighbours dump for
interfaces that *don't* have a master.

Signed-off-by: Lahav Schlesinger 
Reviewed-by: David Ahern 
Link: https://lore.kernel.org/r/20210810090658.2778960-1-lschlesinger@drivenets.com
Signed-off-by: Jakub Kicinski

net: add extack arg for link ops

2021-08-04T09:01:26+00:00

Pass extack arg to validate_linkmsg and validate_link_af callbacks.
If a netlink attribute has a reject_message, use the extended ack
mechanism to carry the message back to user space.

Signed-off-by: Rocco Yue 
Reviewed-by: David Ahern 
Signed-off-by: David S. Miller

net: netlink: add the case when nlh is NULL

2021-07-27T10:43:50+00:00

Add the case when nlh is NULL in nlmsg_report(),
so that the caller doesn't need to deal with this case.

Signed-off-by: Yajun Deng 
Signed-off-by: David S. Miller

rtnetlink: use nlmsg_notify() in rtnetlink_send()

2021-07-16T17:46:35+00:00

The netlink_{broadcast, unicast} don't deal with 'if (err > 0' statement
but nlmsg_{multicast, unicast} do. The nlmsg_notify() contains them.
so use nlmsg_notify() instead. so that the caller wouldn't deal with
'if (err > 0' statement.

v2: use nlmsg_notify() will do well.

Signed-off-by: Yajun Deng 
Signed-off-by: David S. Miller

net: say "local" instead of "static" addresses in ndo_dflt_fdb_{add,del}

2021-06-29T18:31:57+00:00

"Static" is a loaded word, and probably not what the author meant when
the code was written.

In particular, this looks weird:
$ bridge fdb add dev swp0 00:01:02:03:04:05 local        # totally fine, but
$ bridge fdb add dev swp0 00:01:02:03:04:05 static
[ 2020.708298] swp0: FDB only supports static addresses  # hmm what?

By looking at the implementation which uses dev_uc_add/dev_uc_del it is
absolutely clear that only local addresses are supported, and the proper
Network Unreachability Detection state is being used for this purpose
(user space indeed sets NUD_PERMANENT when local addresses are meant).
So it is just the message that is wrong, fix it.

Signed-off-by: Vladimir Oltean 
Signed-off-by: David S. Miller

net: use netdev_info in ndo_dflt_fdb_{add,del}

2021-06-29T18:31:57+00:00

Use the more modern printk helper for network interfaces, which also
contains information about the associated struct device, and results in
overall shorter line lengths compared to printing an open-coded
dev->name.

Signed-off-by: Vladimir Oltean 
Signed-off-by: David S. Miller

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

2021-06-19T02:47:02+00:00

Trivial conflicts in net/can/isotp.c and
tools/testing/selftests/net/mptcp/mptcp_connect.sh

scaled_ppm_to_ppb() was moved from drivers/ptp/ptp_clock.c
to include/linux/ptp_clock_kernel.h in -next so re-apply
the fix there.

Signed-off-by: Jakub Kicinski