linux.git/net/ipv4/devinet.c, branch v6.10

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

ipv4: correctly iterate over the target netns in inet_dump_ifaddr()

2024-05-30T01:43:42+00:00

A recent change to inet_dump_ifaddr had the function incorrectly iterate
over net rather than tgt_net, resulting in the data coming for the
incorrect network namespace.

Fixes: cdb2f80f1c10 ("inet: use xa_array iterator to implement inet_dump_ifaddr()")
Reported-by: Stéphane Graber 
Closes: https://github.com/lxc/incus/issues/892
Bisected-by: Stéphane Graber 
Signed-off-by: Alexander Mikhalitsyn 
Tested-by: Stéphane Graber 
Acked-by: Christian Brauner 
Reviewed-by: Eric Dumazet 
Link: https://lore.kernel.org/r/20240528203030.10839-1-aleksandr.mikhalitsyn@canonical.com
Signed-off-by: Jakub Kicinski

ipv4: Fix address dump when IPv4 is disabled on an interface

2024-05-27T23:46:05+00:00

Cited commit started returning an error when user space requests to dump
the interface's IPv4 addresses and IPv4 is disabled on the interface.
Restore the previous behavior and do not return an error.

Before cited commit:

 # ip address show dev dummy1
 10: dummy1:  mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000
     link/ether e2:40:68:98:d0:18 brd ff:ff:ff:ff:ff:ff
     inet6 fe80::e040:68ff:fe98:d018/64 scope link proto kernel_ll
        valid_lft forever preferred_lft forever
 # ip link set dev dummy1 mtu 67
 # ip address show dev dummy1
 10: dummy1:  mtu 67 qdisc noqueue state UNKNOWN group default qlen 1000
     link/ether e2:40:68:98:d0:18 brd ff:ff:ff:ff:ff:ff

After cited commit:

 # ip address show dev dummy1
 10: dummy1:  mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000
     link/ether 32:2d:69:f2:9c:99 brd ff:ff:ff:ff:ff:ff
     inet6 fe80::302d:69ff:fef2:9c99/64 scope link proto kernel_ll
        valid_lft forever preferred_lft forever
 # ip link set dev dummy1 mtu 67
 # ip address show dev dummy1
 RTNETLINK answers: No such device
 Dump terminated

With this patch:

 # ip address show dev dummy1
 10: dummy1:  mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000
     link/ether de:17:56:bb:57:c0 brd ff:ff:ff:ff:ff:ff
     inet6 fe80::dc17:56ff:febb:57c0/64 scope link proto kernel_ll
        valid_lft forever preferred_lft forever
 # ip link set dev dummy1 mtu 67
 # ip address show dev dummy1
 10: dummy1:  mtu 67 qdisc noqueue state UNKNOWN group default qlen 1000
     link/ether de:17:56:bb:57:c0 brd ff:ff:ff:ff:ff:ff

I fixed the exact same issue for IPv6 in commit c04f7dfe6ec2 ("ipv6: Fix
address dump when IPv6 is disabled on an interface"), but noted [1] that
I am not doing the change for IPv4 because I am not aware of a way to
disable IPv4 on an interface other than unregistering it. I clearly
missed the above case.

[1] https://lore.kernel.org/netdev/20240321173042.2151756-1-idosch@nvidia.com/

Fixes: cdb2f80f1c10 ("inet: use xa_array iterator to implement inet_dump_ifaddr()")
Reported-by: Carolina Jubran 
Reported-by: Yamen Safadi 
Tested-by: Carolina Jubran 
Reviewed-by: Petr Machata 
Signed-off-by: Ido Schimmel 
Reviewed-by: Eric Dumazet 
Reviewed-by: David Ahern 
Link: https://lore.kernel.org/r/20240523110257.334315-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski

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

2024-05-14T17:53:19+00:00

Merge in late fixes to prepare for the 6.10 net-next PR.

Signed-off-by: Jakub Kicinski

inet: fix inet_fill_ifaddr() flags truncation

2024-05-13T20:53:01+00:00

I missed that (struct ifaddrmsg)->ifa_flags was only 8bits,
while (struct in_ifaddr)->ifa_flags is 32bits.

Use a temporary 32bit variable as I did in set_ifa_lifetime()
and check_lifetime().

Fixes: 3ddc2231c810 ("inet: annotate data-races around ifa->ifa_flags")
Reported-by: Yu Watanabe 
Dianosed-by: Yu Watanabe 
Closes: https://github.com/systemd/systemd/pull/32666#issuecomment-2103977928
Signed-off-by: Eric Dumazet 
Reviewed-by: Larysa Zaremba 
Reviewed-by: David Ahern 
Link: https://lore.kernel.org/r/20240510072932.2678952-1-edumazet@google.com
Signed-off-by: Jakub Kicinski

net: ipv{6,4}: Remove the now superfluous sentinel elements from ctl_table array

2024-05-03T12:29:42+00:00

This commit comes at the tail end of a greater effort to remove the
empty elements at the end of the ctl_table arrays (sentinels) which
will reduce the overall build time size of the kernel and run time
memory bloat by ~64 bytes per sentinel (further information Link :
https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/)

* Remove sentinel element from ctl_table structs.
* Remove the zeroing out of an array element (to make it look like a
  sentinel) in sysctl_route_net_init And ipv6_route_sysctl_init.
  This is not longer needed and is safe after commit c899710fe7f9
  ("networking: Update to register_net_sysctl_sz") added the array size
  to the ctl_table registration.
* Remove extra sentinel element in the declaration of devinet_vars.
* Removed the "-1" in __devinet_sysctl_register, sysctl_route_net_init,
  ipv6_sysctl_net_init and ipv4_sysctl_init_net that adjusted for having
  an extra empty element when looping over ctl_table arrays
* Replace the for loop stop condition in __addrconf_sysctl_register that
  tests for procname == NULL with one that depends on array size
* Removing the unprivileged user check in ipv6_route_sysctl_init is
  safe as it is replaced by calling ipv6_route_sysctl_table_size;
  introduced in commit c899710fe7f9 ("networking: Update to
  register_net_sysctl_sz")
* Use a table_size variable to keep the value of ARRAY_SIZE

Signed-off-by: Joel Granados 
Signed-off-by: David S. Miller

inet: use call_rcu_hurry() in inet_free_ifa()

2024-04-29T08:58:58+00:00

This is a followup of commit c4e86b4363ac ("net: add two more
call_rcu_hurry()")

Our reference to ifa->ifa_dev must be freed ASAP
to release the reference to the netdev the same way.

inet_rcu_free_ifa()

	in_dev_put()
	 -> in_dev_finish_destroy()
	   -> netdev_put()

This should speedup device/netns dismantles when CONFIG_RCU_LAZY=y

Signed-off-by: Eric Dumazet 
Reviewed-by: David Ahern 
Signed-off-by: David S. Miller

sysctl: treewide: constify ctl_table_header::ctl_table_arg

2024-04-22T07:56:31+00:00

To be able to constify instances of struct ctl_tables it is necessary to
remove ways through which non-const versions are exposed from the
sysctl core.
One of these is the ctl_table_arg member of struct ctl_table_header.

Constify this reference as a prerequisite for the full constification of
struct ctl_table instances.
No functional change.

Signed-off-by: Thomas Weißschuh 
Reviewed-by: Kees Cook 
Signed-off-by: David S. Miller

netlink: let core handle error cases in dump operations

2024-03-08T04:48:22+00:00

After commit b5a899154aa9 ("netlink: handle EMSGSIZE errors
in the core"), we can remove some code that was not 100 % correct
anyway.

Signed-off-by: Eric Dumazet 
Reviewed-by: Simon Horman 
Reviewed-by: Ido Schimmel 
Reviewed-by: David Ahern 
Link: https://lore.kernel.org/r/20240306102426.245689-1-edumazet@google.com
Signed-off-by: Jakub Kicinski

inet: use xa_array iterator to implement inet_dump_ifaddr()

2024-03-01T11:09:39+00:00

1) inet_dump_ifaddr() can can run under RCU protection
   instead of RTNL.

2) properly return 0 at the end of a dump, avoiding an
   an extra recvmsg() system call.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller