__rtnl_newlink() is 250LoC, but has a few clear sections.
Move the part which creates a new netdev to a separate
function.
For ease of review code will be moved in the next change.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Commit a293974590 ("rtnetlink: avoid frame size warning in rtnl_newlink()")
moved to allocating the largest attribute array of rtnl_newlink()
on the heap. Kalle reports the stack has grown above 1k again:
net/core/rtnetlink.c:3557:1: error: the frame size of 1104 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]
Move more attrs to the heap, wrap them in a struct.
Don't bother with linkinfo, it's referenced a lot and we take
its size so it's awkward to move, plus it's small (6 elements).
Reported-by: Kalle Valo <kvalo@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Tested-by: Kalle Valo <kvalo@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
This reverts commit b6177d3240
ip-link command is testing kernel capability by sending a RTM_NEWLINK
request, without any argument. It accepts everything in reply, except
EOPNOTSUPP and EINVAL (functions iplink_have_newlink / accept_msg)
So we must keep compatiblity here, invalid empty message should not
return EINVAL
Signed-off-by: Florent Fourcot <florent.fourcot@wifirst.fr>
Tested-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
A request without interface name/interface index/interface group cannot
work. We should return EINVAL
Signed-off-by: Florent Fourcot <florent.fourcot@wifirst.fr>
Signed-off-by: Brian Baboch <brian.baboch@wifirst.fr>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
If IFLA_ALT_IFNAME is set and given interface is not found,
we should return ENODEV and be consistent with IFLA_IFNAME
behaviour
This commit extends feature of commit 76c9ac0ee8,
"net: rtnetlink: add possibility to use alternative names as message handle"
CC: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Florent Fourcot <florent.fourcot@wifirst.fr>
Signed-off-by: Brian Baboch <brian.baboch@wifirst.fr>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
buffer called "ifname" given in function rtnl_dev_get
is always valid when called by setlink/newlink,
but contains only empty string when IFLA_IFNAME is not given. So
IFLA_ALT_IFNAME is always ignored
This patch fixes rtnl_dev_get function with a remove of ifname argument,
and move ifname copy in do_setlink when required.
It extends feature of commit 76c9ac0ee8,
"net: rtnetlink: add possibility to use alternative names as message
handle""
CC: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Florent Fourcot <florent.fourcot@wifirst.fr>
Signed-off-by: Brian Baboch <brian.baboch@wifirst.fr>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
When the interface does not exist, and a group is given, the given
parameters are being set to all interfaces of the given group. The given
IFNAME/ALT_IF_NAME are being ignored in that case.
That can be dangerous since a typo (or a deleted interface) can produce
weird side effects for caller:
Case 1:
IFLA_IFNAME=valid_interface
IFLA_GROUP=1
MTU=1234
Case 1 will update MTU and group of the given interface "valid_interface".
Case 2:
IFLA_IFNAME=doesnotexist
IFLA_GROUP=1
MTU=1234
Case 2 will update MTU of all interfaces in group 1. IFLA_IFNAME is
ignored in this case
This behaviour is not consistent and dangerous. In order to fix this issue,
we now return ENODEV when the given IFNAME does not exist.
Signed-off-by: Florent Fourcot <florent.fourcot@wifirst.fr>
Signed-off-by: Brian Baboch <brian.baboch@wifirst.fr>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
When L3 stats are disabled, rtnl_offload_xstats_get_size_stats() returns
size of 0, which is supposed to be an indication that the corresponding
attribute should not be emitted. However, instead, the current code
reserves a 0-byte attribute.
The reason this does not show up as a citation on a kasan kernel is that
netdev_offload_xstats_get(), which is supposed to fill in the data, never
ends up getting called, because rtnl_offload_xstats_get_stats() notices
that the stats are not actually used and skips the call.
Thus a zero-length IFLA_OFFLOAD_XSTATS_L3_STATS attribute ends up in a
response, confusing the userspace.
Fix by skipping the L3-stats related block in rtnl_offload_xstats_fill().
Fixes: 0e7788fd76 ("net: rtnetlink: Add UAPI for obtaining L3 offload xstats")
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://lore.kernel.org/r/591b58e7623edc3eb66dd1fcfa8c8f133d090974.1649794741.git.petrm@nvidia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Add ndm flags/state masks which will be used for bulk delete filtering.
All of these are used by the bridge and vxlan drivers. Also minimal attr
policy validation is added, it is up to ndo_fdb_del_bulk implementers to
further validate them.
Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
When NLM_F_BULK is specified in a fdb del message we need to handle it
differently. First since this is a new call we can strictly validate the
passed attributes, at first only ifindex and vlan are allowed as these
will be the initially supported filter attributes, any other attribute
is rejected. The mac address is no longer mandatory, but we use it
to error out in older kernels because it cannot be specified with bulk
request (the attribute is not allowed) and then we have to dispatch
the call to ndo_fdb_del_bulk if the device supports it. The del bulk
callback can do further validation of the attributes if necessary.
Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a new rtnl flag (RTNL_FLAG_BULK_DEL_SUPPORTED) which is used to
verify that the delete operation allows bulk object deletion. Also emit
a warning if anyone tries to set it for non-delete kind.
Suggested-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a helper which extracts the msg type's kind using the kind mask (0x3).
Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add rtnl kind names instead of using raw values. We'll need to
check for DEL kind later to validate bulk flag support.
Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
There's a number of functions and static variables used
under net/core/ but not from the outside. We currently
dump most of them into netdevice.h. That bad for many
reasons:
- netdevice.h is very cluttered, hard to figure out
what the APIs are;
- netdevice.h is very long;
- we have to touch netdevice.h more which causes expensive
incremental builds.
Create a header under net/core/ and move some declarations.
The new header is also a bit of a catch-all but that's
fine, if we create more specific headers people will
likely over-think where their declaration fit best.
And end up putting them in netdevice.h, again.
More work should be done on splitting netdevice.h into more
targeted headers, but that'd be more time consuming so small
steps.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
In [1], Will raised a potential issue that the cfg80211 code,
which does (from a locking perspective)
rtnl_lock()
wiphy_lock()
rtnl_unlock()
might be suspectible to ABBA deadlocks, because rtnl_unlock()
calls netdev_run_todo(), which might end up calling rtnl_lock()
again, which could then deadlock (see the comment in the code
added here for the scenario).
Some back and forth and thinking ensued, but clearly this can't
happen if the net_todo_list is empty at the rtnl_unlock() here.
Clearly, the code here cannot actually put an entry on it, and
all other users of rtnl_unlock() will empty it since that will
always go through netdev_run_todo(), emptying the list.
So the only other way to get there would be to add to the list
and then unlock the RTNL without going through rtnl_unlock(),
which is only possible through __rtnl_unlock(). However, this
isn't exported and not used in many places, and none of them
seem to be able to unregister before using it.
Therefore, add a WARN_ON() in the code to ensure this invariant
won't be broken, so that the cfg80211 (or any similar) code
stays safe.
[1] https://lore.kernel.org/r/Yjzpo3TfZxtKPMAG@google.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Link: https://lore.kernel.org/r/20220404113847.0ee02e4a70da.Ic73d206e217db20fd22dcec14fe5442ca732804b@changeid
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Property list (altname is a link "property") is wrapped
in a nlattr. nlattrs length is 16bit so practically
speaking the list of properties can't be longer than
that, otherwise user space would have to interpret
broken netlink messages.
Prevent the problem from occurring by checking the length
of the property list before adding new entries.
Reported-by: George Shuklin <george.shuklin@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
George reports that altnames can eat up kernel memory.
We should charge that memory appropriately.
Reported-by: George Shuklin <george.shuklin@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The clang static analyzer reports this issue
rtnetlink.c:5481:2: warning: Undefined or garbage
value returned to caller
return err;
^~~~~~~~~~
There is a function level err variable, in the
list_for_each_entry_rcu block there is a shadow
err. Remove the shadow.
In the same block, the call to nla_nest_start_noflag()
can fail without setting an err. Set the err
to -EMSGSIZE.
Fixes: 216e690631 ("net: rtnetlink: rtnl_fill_statsinfo(): Permit non-EMSGSIZE error returns")
Signed-off-by: Tom Rix <trix@redhat.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The offloaded HW stats are designed to allow per-netdevice enablement and
disablement. Add an attribute, IFLA_STATS_SET_OFFLOAD_XSTATS_L3_STATS,
which should be carried by the RTM_SETSTATS message, and expresses a desire
to toggle L3 offload xstats on or off.
As part of the above, add an exported function rtnl_offload_xstats_notify()
that drivers can use when they have installed or deinstalled the counters
backing the HW stats.
At this point, it is possible to enable, disable and query L3 offload
xstats on netdevices. (However there is no driver actually implementing
these.)
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The offloaded HW stats are designed to allow per-netdevice enablement and
disablement. These stats are only accessible through RTM_GETSTATS, and
therefore should be toggled by a RTM_SETSTATS message. Add it, and the
necessary skeleton handler.
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a new IFLA_STATS_LINK_OFFLOAD_XSTATS child attribute,
IFLA_OFFLOAD_XSTATS_L3_STATS, to carry statistics for traffic that takes
place in a HW router.
The offloaded HW stats are designed to allow per-netdevice enablement and
disablement. Additionally, as a netdevice is configured, it may become or
cease being suitable for binding of a HW counter. Both of these aspects
need to be communicated to the userspace. To that end, add another child
attribute, IFLA_OFFLOAD_XSTATS_HW_S_INFO:
- attr nest IFLA_OFFLOAD_XSTATS_HW_S_INFO
- attr nest IFLA_OFFLOAD_XSTATS_L3_STATS
- attr IFLA_OFFLOAD_XSTATS_HW_S_INFO_REQUEST
- {0,1} as u8
- attr IFLA_OFFLOAD_XSTATS_HW_S_INFO_USED
- {0,1} as u8
Thus this one attribute is a nest that can be used to carry information
about various types of HW statistics, and indexing is very simply done by
wrapping the information for a given statistics suite into the attribute
that carries the suite is the RTM_GETSTATS query. At the same time, because
_HW_S_INFO is nested directly below IFLA_STATS_LINK_OFFLOAD_XSTATS, it is
possible through filtering to request only the metadata about individual
statistics suites, without having to hit the HW to get the actual counters.
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Obtaining stats for the IFLA_STATS_LINK_OFFLOAD_XSTATS nest involves a HW
access, and can fail for more reasons than just netlink message size
exhaustion. Therefore do not always return -EMSGSIZE on the failure path,
but respect the error code provided by the callee. Set the error explicitly
where it is reasonable to assume -EMSGSIZE as the failure reason.
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Later patches add handlers for more HW-backed statistics. An extack will be
useful when communicating HW / driver errors to the client. Add the
arguments as appropriate.
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The filter_mask field of RTM_GETSTATS header determines which top-level
attributes should be included in the netlink response. This saves
processing time by only including the bits that the user cares about
instead of always dumping everything. This is doubly important for
HW-backed statistics that would typically require a trip to the device to
fetch the stats.
So far there was only one HW-backed stat suite per attribute. However,
IFLA_STATS_LINK_OFFLOAD_XSTATS is a nest, and will gain a new stat suite in
the following patches. It would therefore be advantageous to be able to
filter within that nest, and select just one or the other HW-backed
statistics suite.
Extend rtnetlink so that RTM_GETSTATS permits attributes in the payload.
The scheme is as follows:
- RTM_GETSTATS
- struct if_stats_msg
- attr nest IFLA_STATS_GET_FILTERS
- attr IFLA_STATS_LINK_OFFLOAD_XSTATS
- u32 filter_mask
This scheme reuses the existing enumerators by nesting them in a dedicated
context attribute. This is covered by policies as usual, therefore a
gradual opt-in is possible. Currently only IFLA_STATS_LINK_OFFLOAD_XSTATS
nest has filtering enabled, because for the SW counters the issue does not
seem to be that important.
rtnl_offload_xstats_get_size() and _fill() are extended to observe the
requested filters.
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The IFLA_STATS_LINK_OFFLOAD_XSTATS attribute is a nest whose child
attributes carry various special hardware statistics. The code that handles
this nest was written with the idea that all these statistics would be
exposed by the device driver of a physical netdevice.
In the following patches, a new attribute is added to the abovementioned
nest, which however can be defined for some soft netdevices. The NDO-based
approach to querying these does not work, because it is not the soft
netdevice driver that exposes these statistics, but an offloading NIC
driver that does so.
The current code does not scale well to this usage. Simply rewrite it back
to the pattern seen in other fill-like and get_size-like functions
elsewhere.
Extract to helpers the code that is concerned with handling specifically
NDO-backed statistics so that it can be easily reused should more such
statistics be added.
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The currently used names rtnl_get_offload_stats() and
rtnl_get_offload_stats_size() do not clearly show the namespace. The former
function additionally seems to have been named this way in accordance with
the NDO name, as opposed to the naming used in the rtnetlink.c file (and
indeed elsewhere in the netlink handling code). As more and
differently-flavored attributes are introduced, a common clear prefix is
needed for all related functions.
Rename the functions to follow the rtnl_offload_xstats_* naming scheme.
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Both get and dump handlers for RTM_GETSTATS require that a filter_mask, a
mask of which attributes should be emitted in the netlink response, is
unset. rtnl_stats_dump() does include an extack in the bounce,
rtnl_stats_get() however does not. Fix the omission.
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/01feb1f4bbd22a19f6629503c4f366aed6424567.1645020876.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Having to acquire rtnl from netdev_run_todo() for every dismantled
device is not desirable when/if rtnl is under stress.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While looking at one unrelated syzbot bug, I found the replay logic
in __rtnl_newlink() to potentially trigger use-after-free.
It is better to clear master_dev and m_ops inside the loop,
in case we have to replay it.
Fixes: ba7d49b1f0 ("rtnetlink: provide api for getting and setting slave info")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20220201012106.216495-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Eric Dumazet suggested to allow users to modify max GRO packet size.
We have seen GRO being disabled by users of appliances (such as
wifi access points) because of claimed bufferbloat issues,
or some work arounds in sch_cake, to split GRO/GSO packets.
Instead of disabling GRO completely, one can chose to limit
the maximum packet size of GRO packets, depending on their
latency constraints.
This patch adds a per device gro_max_size attribute
that can be changed with ip link command.
ip link set dev eth0 gro_max_size 16000
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Coco Li <lixiaoyan@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The writer acquires dev_base_lock with disabled bottom halves.
The reader can acquire dev_base_lock without disabling bottom halves
because there is no writer in softirq context.
On PREEMPT_RT the softirqs are preemptible and local_bh_disable() acts
as a lock to ensure that resources, that are protected by disabling
bottom halves, remain protected.
This leads to a circular locking dependency if the lock acquired with
disabled bottom halves (as in write_lock_bh()) and somewhere else with
enabled bottom halves (as by read_lock() in netstat_show()) followed by
disabling bottom halves (cxgb_get_stats() -> t4_wr_mbox_meat_timeout()
-> spin_lock_bh()). This is the reverse locking order.
All read_lock() invocation are from sysfs callback which are not invoked
from softirq context. Therefore there is no need to disable bottom
halves while acquiring a write lock.
Acquire the write lock of dev_base_lock without disabling bottom halves.
Reported-by: Pei Zhang <pezhang@redhat.com>
Reported-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
.ndo_change_proto_down was added seemingly to enable out-of-tree
implementations. Over 2.5yrs later we still have no real users
upstream. Hardwire the generic implementation for now, we can
revert once real users materialize. (rocker is a test vehicle,
not a user.)
We need to drop the optimization on the sysfs side, because
unlike ndos priv_flags will be changed at runtime, so we'd
need READ_ONCE/WRITE_ONCE everywhere..
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
dev->gso_max_segs is written under RTNL protection, or when the device is
not yet visible, but is read locklessly.
Add netif_set_gso_max_segs() helper.
Add the READ_ONCE()/WRITE_ONCE() pairs, and use netif_set_gso_max_segs()
where we can to better document what is going on.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Although if_info_size is assigned, it has not been used. And the variable
should also be deleted.
The clang_analyzer complains as follows:
net/core/rtnetlink.c:3806: warning:
Although the value stored to 'if_info_size' is used in the enclosing
expression, the value is never actually read from 'if_info_size'.
Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: luo penghao <luo.penghao@zte.com.cn>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Make use of netdev helper functions to improve code readability.
Replace 'dev->priv_flags & IFF_EBRIDGE' with netif_is_bridge_master(dev).
Signed-off-by: Kyungrok Chung <acadx0@gmail.com>
Reviewed-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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: 10c9ead9f3 ("rtnetlink: add new RTM_GETSTATS message to dump link stats")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Roopa Prabhu <roopa@nvidia.com>
Acked-by: Roopa Prabhu <roopa@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
It no need barrier when assigning a NULL value to an RCU protected
pointer. So use RCU_INIT_POINTER() instead for more fast.
Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
Signed-off-by: David S. Miller <davem@davemloft.net>
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: <BROADCAST,NOARP> 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: <BROADCAST,NOARP> 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: <BROADCAST,NOARP> 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: <BROADCAST,NOARP> 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: d8a5ec6727 ("[NET]: netlink support for moving devices between network namespaces.")
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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 <lschlesinger@drivenets.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20210810090658.2778960-1-lschlesinger@drivenets.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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 <rocco.yue@mediatek.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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 <yajun.deng@linux.dev>
Signed-off-by: David S. Miller <davem@davemloft.net>
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 <yajun.deng@linux.dev>
Signed-off-by: David S. Miller <davem@davemloft.net>
"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 <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
