switch netlink_getsockbyfilp() to taking descriptor

the only call site (in do_mq_notify()) obtains the argument
from an immediately preceding fdget() and it is immediately
followed by fdput(); might

switch netlink_getsockbyfilp() to taking descriptor

the only call site (in do_mq_notify()) obtains the argument
from an immediately preceding fdget() and it is immediately
followed by fdput(); might as well just replace it with
a variant that would take a descriptor instead of struct file *
and have file lookups handled inside that function.

Reviewed-by: Christian Brauner <[email protected]>
Signed-off-by: Al Viro <[email protected]>

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genetlink: extend info user-storage to match NL cb ctx

This allows a more uniform implementation of non-dump and dump
operations, and will be used later in the series to avoid some
per-operation all

genetlink: extend info user-storage to match NL cb ctx

This allows a more uniform implementation of non-dump and dump
operations, and will be used later in the series to avoid some
per-operation allocation.

Additionally rename the NL_ASSERT_DUMP_CTX_FITS macro, to
fit a more extended usage.

Suggested-by: Jakub Kicinski <[email protected]>
Reviewed-by: Jakub Kicinski <[email protected]>
Reviewed-by: Jiri Pirko <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>
Link: https://patch.msgid.link/1130cc2896626b84587a2a5f96a5c6829638f4da.1728460186.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <[email protected]>

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net: netlink: remove the cb_mutex "injection" from netlink core

Back in 2007, in commit af65bdfce98d ("[NETLINK]: Switch cb_lock spinlock
to mutex and allow to override it") netlink core was extende

net: netlink: remove the cb_mutex "injection" from netlink core

Back in 2007, in commit af65bdfce98d ("[NETLINK]: Switch cb_lock spinlock
to mutex and allow to override it") netlink core was extended to allow
subsystems to replace the dump mutex lock with its own lock.

The mechanism was used by rtnetlink to take rtnl_lock but it isn't
sufficiently flexible for other users. Over the 17 years since
it was added no other user appeared. Since rtnetlink needs conditional
locking now, and doesn't use it either, axe this feature complete.

Signed-off-by: Jakub Kicinski <[email protected]>
Reviewed-by: Kuniyuki Iwashima <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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rtnetlink: add RTNL_FLAG_DUMP_UNLOCKED flag

Similarly to RTNL_FLAG_DOIT_UNLOCKED, this new flag
allows dump operations registered via rtnl_register()
or rtnl_register_module() to opt-out from RTNL p

rtnetlink: add RTNL_FLAG_DUMP_UNLOCKED flag

Similarly to RTNL_FLAG_DOIT_UNLOCKED, this new flag
allows dump operations registered via rtnl_register()
or rtnl_register_module() to opt-out from RTNL protection.

Signed-off-by: Eric Dumazet <[email protected]>
Reviewed-by: Donald Hunter <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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netlink: introduce typedef for filter function

Make the code using filter function a bit nicer by consolidating the
filter function arguments using typedef.

Suggested-by: Andy Shevchenko <andriy.sh

netlink: introduce typedef for filter function

Make the code using filter function a bit nicer by consolidating the
filter function arguments using typedef.

Suggested-by: Andy Shevchenko <[email protected]>
Signed-off-by: Jiri Pirko <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>

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rtnetlink: introduce nlmsg_new_large and use it in rtnl_getlink

if a PF has 256 or more VFs, ip link command will allocate an order 3
memory or more, and maybe trigger OOM due to memory fragment,
th

rtnetlink: introduce nlmsg_new_large and use it in rtnl_getlink

if a PF has 256 or more VFs, ip link command will allocate an order 3
memory or more, and maybe trigger OOM due to memory fragment,
the VFs needed memory size is computed in rtnl_vfinfo_size.

so introduce nlmsg_new_large which calls netlink_alloc_large_skb in
which vmalloc is used for large memory, to avoid the failure of
allocating memory

ip invoked oom-killer: gfp_mask=0xc2cc0(GFP_KERNEL|__GFP_NOWARN|\
__GFP_COMP|__GFP_NOMEMALLOC), order=3, oom_score_adj=0
CPU: 74 PID: 204414 Comm: ip Kdump: loaded Tainted: P OE
Call Trace:
dump_stack+0x57/0x6a
dump_header+0x4a/0x210
oom_kill_process+0xe4/0x140
out_of_memory+0x3e8/0x790
__alloc_pages_slowpath.constprop.116+0x953/0xc50
__alloc_pages_nodemask+0x2af/0x310
kmalloc_large_node+0x38/0xf0
__kmalloc_node_track_caller+0x417/0x4d0
__kmalloc_reserve.isra.61+0x2e/0x80
__alloc_skb+0x82/0x1c0
rtnl_getlink+0x24f/0x370
rtnetlink_rcv_msg+0x12c/0x350
netlink_rcv_skb+0x50/0x100
netlink_unicast+0x1b2/0x280
netlink_sendmsg+0x355/0x4a0
sock_sendmsg+0x5b/0x60
____sys_sendmsg+0x1ea/0x250
___sys_sendmsg+0x88/0xd0
__sys_sendmsg+0x5e/0xa0
do_syscall_64+0x33/0x40
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f95a65a5b70

Cc: Yunsheng Lin <[email protected]>
Signed-off-by: Li RongQing <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

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netlink: Add new netlink_release function

A new function netlink_release is added in netlink_sock to store the
protocol's release function. This is called when the socket is deleted.
This can be sup

netlink: Add new netlink_release function

A new function netlink_release is added in netlink_sock to store the
protocol's release function. This is called when the socket is deleted.
This can be supplied by the protocol via the release function in
netlink_kernel_cfg. This is being added for the NETLINK_CONNECTOR
protocol, so it can free it's data when socket is deleted.

Signed-off-by: Anjali Kulkarni <[email protected]>
Reviewed-by: Liam R. Howlett <[email protected]>
Acked-by: Jakub Kicinski <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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netlink: Reverse the patch which removed filtering

To use filtering at the connector & cn_proc layers, we need to enable
filtering in the netlink layer. This reverses the patch which removed
netlink

netlink: Reverse the patch which removed filtering

To use filtering at the connector & cn_proc layers, we need to enable
filtering in the netlink layer. This reverses the patch which removed
netlink filtering - commit ID for that patch:
549017aa1bb7 (netlink: remove netlink_broadcast_filtered).

Signed-off-by: Anjali Kulkarni <[email protected]>
Reviewed-by: Liam R. Howlett <[email protected]>
Acked-by: Jakub Kicinski <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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netlink: support extack in dump ->start()

Commit 4a19edb60d02 ("netlink: Pass extack to dump handlers")
added extack support to netlink dumps. It was focused on rtnl
and since rtnl does not use ->st

netlink: support extack in dump ->start()

Commit 4a19edb60d02 ("netlink: Pass extack to dump handlers")
added extack support to netlink dumps. It was focused on rtnl
and since rtnl does not use ->start(), ->done() callbacks
it ignored those. Genetlink on the other hand uses ->start()
extensively, for parsing and input validation.

Pass the extact in via struct netlink_dump_control and link
it to cb for the time of ->start(). Both struct netlink_dump_control
and extack itself live on the stack so we can't keep the same
extack for the duration of the dump. This means that the extack
visible in ->start() and each ->dump() callbacks will be different.
Corner cases like reporting a warning message in DONE across dump
calls are still not supported.

We could put the extack (for dumps) in the socket struct,
but layering makes it slightly awkward (extack pointer is decided
before the DO / DUMP split).

The genetlink dump error extacks are now surfaced:

$ cli.py --spec netlink/specs/ethtool.yaml --dump channels-get
lib.ynl.NlError: Netlink error: Invalid argument
nl_len = 64 (48) nl_flags = 0x300 nl_type = 2
error: -22 extack: {'msg': 'request header missing'}

Previously extack was missing:

$ cli.py --spec netlink/specs/ethtool.yaml --dump channels-get
lib.ynl.NlError: Netlink error: Invalid argument
nl_len = 36 (20) nl_flags = 0x100 nl_type = 2
error: -22

Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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netlink: Add a macro to set policy message with format string

Similar to NL_SET_ERR_MSG_FMT, add a macro which sets netlink policy
error message with a format string.

Signed-off-by: Shay Agroskin <

netlink: Add a macro to set policy message with format string

Similar to NL_SET_ERR_MSG_FMT, add a macro which sets netlink policy
error message with a format string.

Signed-off-by: Shay Agroskin <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>

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netlink: remove unused 'compare' function

No users in the tree. Tested with allmodconfig build.

Signed-off-by: Florian Westphal <[email protected]>
Link: https://lore.kernel.org/r/20230308142006.20879-

netlink: remove unused 'compare' function

No users in the tree. Tested with allmodconfig build.

Signed-off-by: Florian Westphal <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

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netlink: provide an ability to set default extack message

In netdev common pattern, extack pointer is forwarded to the drivers
to be filled with error message. However, the caller can easily
overwri

netlink: provide an ability to set default extack message

In netdev common pattern, extack pointer is forwarded to the drivers
to be filled with error message. However, the caller can easily
overwrite the filled message.

Instead of adding multiple "if (!extack->_msg)" checks before any
NL_SET_ERR_MSG() call, which appears after call to the driver, let's
add new macro to common code.

[1] https://lore.kernel.org/all/Y9Irgrgf3uxOjwUm@unreal
Reviewed-by: Simon Horman <[email protected]>
Reviewed-by: Nikolay Aleksandrov <[email protected]>
Signed-off-by: Leon Romanovsky <[email protected]>
Link: https://lore.kernel.org/r/6993fac557a40a1973dfa0095107c3d03d40bec1.1675171790.git.leon@kernel.org
Signed-off-by: Jakub Kicinski <[email protected]>

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netlink: fix spelling mistake in dump size assert

Commit 2c7bc10d0f7b ("netlink: add macro for checking dump ctx size")
misspelled the name of the assert as asset, missing an R.

Reported-by: Ido Sc

netlink: fix spelling mistake in dump size assert

Commit 2c7bc10d0f7b ("netlink: add macro for checking dump ctx size")
misspelled the name of the assert as asset, missing an R.

Reported-by: Ido Schimmel <[email protected]>
Reviewed-by: Ido Schimmel <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

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netlink: add macro for checking dump ctx size

We encourage casting struct netlink_callback::ctx to a local
struct (in a comment above the field). Provide a convenience
macro for checking if the loca

netlink: add macro for checking dump ctx size

We encourage casting struct netlink_callback::ctx to a local
struct (in a comment above the field). Provide a convenience
macro for checking if the local struct fits into the ctx.

Reviewed-by: Jacob Keller <[email protected]>
Reviewed-by: Jiri Pirko <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>

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netlink: add support for formatted extack messages

Include an 80-byte buffer in struct netlink_ext_ack that can be used
for scnprintf()ed messages. This does mean that the resulting string
can't

netlink: add support for formatted extack messages

Include an 80-byte buffer in struct netlink_ext_ack that can be used
for scnprintf()ed messages. This does mean that the resulting string
can't be enumerated, translated etc. in the way NL_SET_ERR_MSG() was
designed to allow.

Signed-off-by: Edward Cree <[email protected]>
Reviewed-by: Jakub Kicinski <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>

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netlink: add helpers for extack attr presence checking

Being able to check attribute presence and set extack
if not on one line is handy, add helpers.

Reviewed-by: Johannes Berg <johannes@sipsoluti

netlink: add helpers for extack attr presence checking

Being able to check attribute presence and set extack
if not on one line is handy, add helpers.

Reviewed-by: Johannes Berg <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>

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netlink: add support for ext_ack missing attributes

There is currently no way to report via extack in a structured way
that an attribute is missing. This leads to families resorting to
string messag

netlink: add support for ext_ack missing attributes

There is currently no way to report via extack in a structured way
that an attribute is missing. This leads to families resorting to
string messages.

Add a pair of attributes - @offset and @type for machine-readable
way of reporting missing attributes. The @offset points to the
nest which should have contained the attribute, @type is the
expected nla_type. The offset will be skipped if the attribute
is missing at the message level rather than inside a nest.

User space should be able to figure out which attribute enum
(AKA attribute space AKA attribute set) the nest pointed to by
@offset is using.

Reviewed-by: Johannes Berg <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>

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netlink: remove nl_set_extack_cookie_u32()

Not used since v5.10.

Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

netlink: remove netlink_broadcast_filtered

No users in tree since commit a3498436b3a0 ("netns: restrict uevents"),
so remove this functionality.

Cc: Christian Brauner <[email protected]>

netlink: remove netlink_broadcast_filtered

No users in tree since commit a3498436b3a0 ("netns: restrict uevents"),
so remove this functionality.

Cc: Christian Brauner <[email protected]>
Signed-off-by: Florian Westphal <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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netlink: simplify nl_set_extack_cookie_u64(), nl_set_extack_cookie_u32()

Taking address of a function argument directly works just fine.

Signed-off-by: Alexey Dobriyan <[email protected]>
Signed-

netlink: simplify nl_set_extack_cookie_u64(), nl_set_extack_cookie_u32()

Taking address of a function argument directly works just fine.

Signed-off-by: Alexey Dobriyan <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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netlink: add tracepoint at NL_SET_ERR_MSG

Often userspace won't request the extack information, or they don't log it
because of log level or so, and even when they do, sometimes it's not
enough to k

netlink: add tracepoint at NL_SET_ERR_MSG

Often userspace won't request the extack information, or they don't log it
because of log level or so, and even when they do, sometimes it's not
enough to know exactly what caused the error.

Netlink extack is the standard way of reporting erros with descriptive
error messages. With a trace point on it, we then can know exactly where
the error happened, regardless of userspace app. Also, we can even see if
the err msg was overwritten.

The wrapper do_trace_netlink_extack() is because trace points shouldn't be
called from .h files, as trace points are not that small, and the function
call to do_trace_netlink_extack() on the macros is not protected by
tracepoint_enabled() because the macros are called from modules, and this
would require exporting some trace structs. As this is error path, it's
better to export just the wrapper instead.

v2: removed leftover tracepoint declaration

Signed-off-by: Marcelo Ricardo Leitner <[email protected]>
Reviewed-by: David Ahern <[email protected]>
Link: https://lore.kernel.org/r/4546b63e67b2989789d146498b13cc09e1fdc543.1612403190.git.marcelo.leitner@gmail.com
Signed-off-by: Jakub Kicinski <[email protected]>

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rtnetlink: fix data overflow in rtnl_calcit()

"ip addr show" command execute error when we have a physical
network card with a large number of VFs

The return value of if_nlmsg_size() in rtnl_calcit

rtnetlink: fix data overflow in rtnl_calcit()

"ip addr show" command execute error when we have a physical
network card with a large number of VFs

The return value of if_nlmsg_size() in rtnl_calcit() will exceed
range of u16 data type when any network cards has a larger number of
VFs. rtnl_vfinfo_size() will significant increase needed dump size when
the value of num_vfs is larger.

Eventually we get a wrong value of min_ifinfo_dump_size because of overflow
which decides the memory size needed by netlink dump and netlink_dump()
will return -EMSGSIZE because of not enough memory was allocated.

So fix it by promoting min_dump_alloc data type to u32 to
avoid whole netlink message size overflow and it's also align
with the data type of struct netlink_callback{}.min_dump_alloc
which is assigned by return value of rtnl_calcit()

Signed-off-by: Di Zhu <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

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netlink: export policy in extended ACK

Add a new attribute NLMSGERR_ATTR_POLICY to the extended ACK
to advertise the policy, e.g. if an attribute was out of range,
you'll know the range that's permi

netlink: export policy in extended ACK

Add a new attribute NLMSGERR_ATTR_POLICY to the extended ACK
to advertise the policy, e.g. if an attribute was out of range,
you'll know the range that's permissible.

Add new NL_SET_ERR_MSG_ATTR_POL() and NL_SET_ERR_MSG_ATTR_POL()
macros to set this, since realistically it's only useful to do
this when the bad attribute (offset) is also returned.

Use it in lib/nlattr.c which practically does all the policy
validation.

v2:
- add and use netlink_policy_dump_attr_size_estimate()
v3:
- remove redundant break
v4:
- really remove redundant break ... sorry

Reviewed-by: Jakub Kicinski <[email protected]>
Signed-off-by: Johannes Berg <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>

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netlink: check for null extack in cookie helpers

Unlike NL_SET_ERR_* macros, nl_set_extack_cookie_u64() and
nl_set_extack_cookie_u32() helpers do not check extack argument for null
and neither do th

netlink: check for null extack in cookie helpers

Unlike NL_SET_ERR_* macros, nl_set_extack_cookie_u64() and
nl_set_extack_cookie_u32() helpers do not check extack argument for null
and neither do their callers, as syzbot recently discovered for
ethnl_parse_header().

Instead of fixing the callers and leaving the trap in place, add check of
null extack to both helpers to make them consistent with NL_SET_ERR_*
macros.

v2: drop incorrect second Fixes tag

Fixes: 2363d73a2f3e ("ethtool: reject unrecognized request flags")
Reported-by: [email protected]
Signed-off-by: Michal Kubecek <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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netlink: add nl_set_extack_cookie_u32()

Similar to existing nl_set_extack_cookie_u64(), add new helper
nl_set_extack_cookie_u32() which sets extack cookie to a u32 value.

Signed-off-by: Michal Kube

netlink: add nl_set_extack_cookie_u32()

Similar to existing nl_set_extack_cookie_u64(), add new helper
nl_set_extack_cookie_u32() which sets extack cookie to a u32 value.

Signed-off-by: Michal Kubecek <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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