ncdevmem is a devmem TCP netcat. It works similarly to netcat, but it
sends and receives data using the devmem TCP APIs. It uses udmabuf as
the dmabuf provider. It is compatible with a regular netcat running on
a peer, or a ncdevmem running on a peer.
In addition to normal netcat support, ncdevmem has a validation mode,
where it sends a specific pattern and validates this pattern on the
receiver side to ensure data integrity.
Suggested-by: Stanislav Fomichev <sdf@fomichev.me>
Signed-off-by: Mina Almasry <almasrymina@google.com>
Link: https://patch.msgid.link/20240910171458.219195-13-almasrymina@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Execution of command:
./tools/net/ynl/cli.py --spec Documentation/netlink/specs/dpll.yaml /
--subscribe "monitor" --sleep 10
fails with:
File "/repo/./tools/net/ynl/cli.py", line 109, in main
ynl.check_ntf()
File "/repo/tools/net/ynl/lib/ynl.py", line 924, in check_ntf
op = self.rsp_by_value[nl_msg.cmd()]
KeyError: 19
Parsing Generic Netlink notification messages performs lookup for op in
the message. The message was not yet decoded, and is not yet considered
GenlMsg, thus msg.cmd() returns Generic Netlink family id (19) instead of
proper notification command id (i.e.: DPLL_CMD_PIN_CHANGE_NTF=13).
Allow the op to be obtained within NetlinkProtocol.decode(..) itself if the
op was not passed to the decode function, thus allow parsing of Generic
Netlink notifications without causing the failure.
Suggested-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://lore.kernel.org/netdev/m2le0n5xpn.fsf@gmail.com/
Fixes: 0a966d606c ("tools/net/ynl: Fix extack decoding for directional ops")
Signed-off-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://patch.msgid.link/20240904135034.316033-1-arkadiusz.kubalewski@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Someone reported on GitHub that the YNL NIPA test is failing
when run locally. The test builds the tools, and it hits:
netdev.c:82:9: warning: ignoring return value of ‘scanf’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
82 | scanf("%d", &ifindex);
I can't repro this on my setups but error seems clear enough.
Link: https://github.com/linux-netdev/nipa/discussions/37
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Link: https://patch.msgid.link/20240828173609.2951335-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Currently the parsing code generator assumes that the yaml
specification file name and the main 'name' attribute carried
inside correspond, that is the field is the c-name representation
of the file basename.
The above assumption held true within the current tree, but will be
hopefully broken soon by the upcoming net shaper specification.
Additionally, it makes the field 'name' itself useless.
Lift the assumption, always computing the generated include file
name from the generated c file name.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Link: https://patch.msgid.link/24da5a3596d814beeb12bd7139a6b4f89756cc19.1724165948.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
There are a couple of statements with two following semicolons,
replace these with just one semicolon.
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://patch.msgid.link/20240802113436.448939-1-colin.i.king@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Support building the C YNL userspace library into one big static file.
We can then link selftests against it for easy to use C netlink
interface.
Signed-off-by: Mina Almasry <almasrymina@google.com>
Link: https://patch.msgid.link/20240628003253.1694510-14-almasrymina@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add a protocol spec for tcp_metrics, so that it's accessible via YNL.
Useful at the very least for testing fixes.
In this episode of "10,000 ways to complicate netlink" the metric
nest has defines which are off by 1. iproute2 does:
struct rtattr *m[TCP_METRIC_MAX + 1 + 1];
parse_rtattr_nested(m, TCP_METRIC_MAX + 1, a);
for (i = 0; i < TCP_METRIC_MAX + 1; i++) {
// ...
attr = m[i + 1];
This is too weird to support in YNL, add a new set of defines
with _correct_ values to the official kernel header.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
CMIS compliant modules such as QSFP-DD might be running a firmware that
can be updated in a vendor-neutral way by exchanging messages between
the host and the module as described in section 7.3.1 of revision 5.2 of
the CMIS standard.
Add a pair of new ethtool messages that allow:
* User space to trigger firmware update of transceiver modules
* The kernel to notify user space about the progress of the process
The user interface is designed to be asynchronous in order to avoid
RTNL being held for too long and to allow several modules to be
updated simultaneously. The interface is designed with CMIS compliant
modules in mind, but kept generic enough to accommodate future use
cases, if these arise.
Signed-off-by: Danielle Ratson <danieller@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use display hints for formatting scalar attrs. This is specifically
useful for formatting IPv4 addresses carried typically as u32.
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://patch.msgid.link/20240626201234.2572964-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Dan, who's working on C++ YNL, pointed out that the C code
does not make policies const. Sprinkle some 'const's around.
Reported-by: Dan Melnic <dmm@meta.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Reviewed-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Folks working on a C++ codegen would like to reuse the attribute
helpers directly. Add the few necessary casts, it's not too ugly.
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Reviewed-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Link: https://lore.kernel.org/r/20240529192031.3785761-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
For type String and Binary we are currently usinig the exact-len
limit value as is without attempting any name resolution.
However, the spec may specify the name of a constant rather than an
actual value, which would result in using the constant name as is
and thus break the policy.
Ensure the limit value is passed to get_limit(), which will always
attempt resolving the name before printing the policy rule.
Signed-off-by: Antonio Quartulli <a@unstable.cc>
Link: https://lore.kernel.org/r/20240510232202.24051-1-a@unstable.cc
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
I often forget the exact naming of ops and have to look at
the spec to find it. Add support for listing the operations:
$ ./cli.py --spec .../netdev.yaml --list-ops
dev-get [ do, dump ]
page-pool-get [ do, dump ]
page-pool-stats-get [ do, dump ]
queue-get [ do, dump ]
napi-get [ do, dump ]
qstats-get [ dump ]
For completeness also support listing all ops (including
notifications:
# ./cli.py --spec .../netdev.yaml --list-msgs
dev-get [ dump, do ]
dev-add-ntf [ notify ]
dev-del-ntf [ notify ]
dev-change-ntf [ notify ]
page-pool-get [ dump, do ]
page-pool-add-ntf [ notify ]
page-pool-del-ntf [ notify ]
page-pool-change-ntf [ notify ]
page-pool-stats-get [ dump, do ]
queue-get [ dump, do ]
napi-get [ dump, do ]
qstats-get [ dump ]
Use double space after the name for slightly easier to read
output.
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://lore.kernel.org/r/20240502164043.2130184-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When using YNL in tests appending the doc string to the type
name makes it harder to check that we got the correct error.
Put the doc under a separate key.
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://lore.kernel.org/r/20240426003111.359285-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
NLMSG_DONE contains an error code, it has to be extracted.
Prior to this change all dumps will end in success,
and in case of failure the result is silently truncated.
Fixes: e4b48ed460 ("tools: ynl: add a completely generic client")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://lore.kernel.org/r/20240420020827.3288615-1-kuba@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Add a "--multi <do-op> <json>" command line to ynl that makes it
possible to add several operations to a single netlink request payload.
The --multi command line option is repeated for each operation.
This is used by the nftables family for transaction batches. For
example:
./tools/net/ynl/cli.py \
--spec Documentation/netlink/specs/nftables.yaml \
--multi batch-begin '{"res-id": 10}' \
--multi newtable '{"name": "test", "nfgen-family": 1}' \
--multi newchain '{"name": "chain", "table": "test", "nfgen-family": 1}' \
--multi batch-end '{"res-id": 10}'
[None, None, None, None]
It can also be used for bundling get requests:
./tools/net/ynl/cli.py \
--spec Documentation/netlink/specs/nftables.yaml \
--multi gettable '{"name": "test", "nfgen-family": 1}' \
--multi getchain '{"name": "chain", "table": "test", "nfgen-family": 1}' \
--output-json
[{"name": "test", "use": 1, "handle": 1, "flags": [],
"nfgen-family": 1, "version": 0, "res-id": 2},
{"table": "test", "name": "chain", "handle": 1, "use": 0,
"nfgen-family": 1, "version": 0, "res-id": 2}]
Signed-off-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://lore.kernel.org/r/20240418104737.77914-4-donald.hunter@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
NetlinkProtocol.decode() was looking up ops by response value which breaks
when it is used for extack decoding of directional ops. Instead, pass
the op to decode().
Signed-off-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://lore.kernel.org/r/20240418104737.77914-3-donald.hunter@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
YNL currently reports None for empty dump:
$ cli.py ...netdev.yaml --dump page-pool-get
None
This doesn't matter for the CLI but when writing YNL based tests
having to deal with either list or None is annoying. Limit the
None conversion to non-dump ops:
$ cli.py ...netdev.yaml --dump page-pool-get
[]
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://lore.kernel.org/r/20240412141436.828666-3-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add binary and integer sub-type support for indexed-array to display bond
arp and ns targets. Here is what the result looks like:
# ip link add bond0 type bond mode 1 \
arp_ip_target 192.168.1.1,192.168.1.2 ns_ip6_target 2001::1,2001::2
# ./tools/net/ynl/cli.py --spec Documentation/netlink/specs/rt_link.yaml \
--do getlink --json '{"ifname": "bond0"}' --output-json | jq '.linkinfo'
"arp-ip-target": [
"192.168.1.1",
"192.168.1.2"
],
[...]
"ns-ip6-target": [
"2001::1",
"2001::2"
],
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Link: https://lore.kernel.org/r/20240404063114.1221532-3-liuhangbin@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Typing e.nl_msg.error when processing exception is a bit tedious
and counter-intuitive. Set a local .error member to the positive
value of the netlink level error.
Reviewed-by: Petr Machata <petrm@nvidia.com>
Link: https://lore.kernel.org/r/20240403023426.1762996-3-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
ethtool.py depends on yml files in a specific location of the linux kernel
tree. Using relative lookup for those files means that ethtool.py would
need to be run under tools/net/ynl/. Lookup needed yml files without
depending on the current working directory that ethtool.py is invoked from.
Signed-off-by: Rahul Rameshbabu <rrameshbabu@nvidia.com>
Reviewed-by: Dragos Tatulea <dtatulea@nvidia.com>
Link: https://lore.kernel.org/r/20240402204000.115081-1-rrameshbabu@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Checking if dump is empty requires a couple of casts.
Add a convenient wrapper.
Add an example use in the netdev sample, loopback is always
present so an empty dump is an error.
Reviewed-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Link: https://lore.kernel.org/r/20240329181651.319326-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Update ynl-gen-rst to generate hyperlinks to definitions, attribute
sets and sub-messages from all the places that reference them.
Note that there is a single label namespace for all of the kernel docs.
Hyperlinks within a single netlink doc need to be qualified by the
family name to avoid collisions.
The label format is 'family-type-name' which gives, for example,
'rt-link-attribute-set-link-attrs' as the link id.
Signed-off-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://lore.kernel.org/r/20240329135021.52534-3-donald.hunter@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The tables of contents in the generated Netlink docs include individual
attribute definitions. This can make the contents exceedingly long and
repeats a lot of what is on the rest of the pages. See for example:
https://docs.kernel.org/networking/netlink_spec/tc.html
Add a depth limit to the contents directive in generated .rst files to
limit the contents depth to 3 levels. This reduces the contents to:
- Family
- Summary
- Operations
- op-one
- op-two
- ...
- Definitions
- struct-one
- struct-two
- enum-one
- ...
- Attribute sets
- attrs-one
- attrs-two
- ...
Signed-off-by: Donald Hunter <donald.hunter@gmail.com>
Reviewed-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20240329135021.52534-2-donald.hunter@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The NLMSGERR_ATTR_POLICY extack attribute has been ignored by ynl up to
now. Extend extack decoding to include _POLICY and the nested
NL_POLICY_TYPE_ATTR_* attributes.
For example:
./tools/net/ynl/cli.py \
--spec Documentation/netlink/specs/rt_link.yaml \
--create --do newlink --json '{
"ifname": "12345678901234567890",
"linkinfo": {"kind": "bridge"}
}'
Netlink error: Numerical result out of range
nl_len = 104 (88) nl_flags = 0x300 nl_type = 2
error: -34 extack: {'msg': 'Attribute failed policy validation',
'policy': {'max-length': 15, 'type': 'string'}, 'bad-attr': '.ifname'}
Signed-off-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://lore.kernel.org/r/20240328155636.64688-1-donald.hunter@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Some times it would be convenient to read the integer as hex, like
mask values.
Suggested-by: Donald Hunter <donald.hunter@gmail.com>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Link: https://lore.kernel.org/r/20240327123130.1322921-2-liuhangbin@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When we set members of simple nested structures in requests
we need to set "presence" bits for all the nesting layers
below. This has nothing to do with the presence type of
the last layer.
Fixes: be5bea1cc0 ("net: add basic C code generators for Netlink")
Reviewed-by: Breno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20240321020214.1250202-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
I "extracted" YNL C into a GitHub repo to make it easier
to use in other projects: https://github.com/linux-netdev/ynl-c
GitHub actions use Ubuntu by default, and the kernel headers
there are missing f329a0ebea ("genetlink: correct uAPI defines").
Add the direct include workaround for nlctrl.
Fixes: 768e044a5f ("doc/netlink/specs: Add spec for nlctrl netlink family")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://lore.kernel.org/r/20240315002108.523232-1-kuba@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The family struct is auto-generated for new families, support
use of the sock_priv_* mechanism added in commit a731132424
("genetlink: introduce per-sock family private storage").
For example if the family wants to use struct sk_buff as its
private struct (unrealistic but just for illustration), it would
add to its spec:
kernel-family:
headers: [ "linux/skbuff.h" ]
sock-priv: struct sk_buff
ynl-gen-c will declare the appropriate priv size and hook
in function prototypes to be implemented by the family.
Link: https://lore.kernel.org/r/20240308190319.2523704-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Support using pre-defined values in checks so we don't need to use hard
code number for the string, binary length. e.g. we have a definition like
#define TEAM_STRING_MAX_LEN 32
Which defined in yaml like:
definitions:
-
name: string-max-len
type: const
value: 32
It can be used in the attribute-sets like
attribute-sets:
-
name: attr-option
name-prefix: team-attr-option-
attributes:
-
name: name
type: string
checks:
len: string-max-len
With this patch it will be converted to
[TEAM_ATTR_OPTION_NAME] = { .type = NLA_STRING, .len = TEAM_STRING_MAX_LEN, }
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Link: https://lore.kernel.org/r/20240311140727.109562-1-liuhangbin@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Running the page-pool sample on production machines under moderate
networking load shows recycling rate higher than 100%:
$ page-pool
eth0[2] page pools: 14 (zombies: 0)
refs: 89088 bytes: 364904448 (refs: 0 bytes: 0)
recycling: 100.3% (alloc: 1392:2290247724 recycle: 469289484:1828235386)
Note that outstanding refs (89088) == slow alloc * cache size (1392 * 64)
which means this machine is recycling page pool pages perfectly, not
a single page has been released.
The extra 0.3% is because sample ignores allocations from the ptr_ring.
Treat those the same as alloc_fast, the ring vs cache alloc is
already captured accurately enough by recycling stats.
With the fix:
$ page-pool
eth0[2] page pools: 14 (zombies: 0)
refs: 89088 bytes: 364904448 (refs: 0 bytes: 0)
recycling: 100.0% (alloc: 1392:2331141604 recycle: 473625579:1857460661)
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The nlctrl genetlink-legacy family uses nest-type-value encoding as
described in Documentation/userspace-api/netlink/genetlink-legacy.rst
Add nest-type-value decoding to ynl.
Signed-off-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://lore.kernel.org/r/20240306231046.97158-5-donald.hunter@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
ynl-gen-c generates e.g. 'calloc(mcast_groups, sizeof(*dst->mcast_groups))'
for array-nest attrs when it should be 'n_mcast_groups'.
Add a 'n_' prefix in the generated code for array-nests.
Signed-off-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://lore.kernel.org/r/20240306231046.97158-4-donald.hunter@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
ynl does not handle NlError exceptions so they get reported like program
failures. Handle the NlError exceptions and report the netlink errors
more cleanly.
Example now:
Netlink error: No such file or directory
nl_len = 44 (28) nl_flags = 0x300 nl_type = 2
error: -2 extack: {'bad-attr': '.op'}
Example before:
Traceback (most recent call last):
File "/home/donaldh/net-next/./tools/net/ynl/cli.py", line 81, in <module>
main()
File "/home/donaldh/net-next/./tools/net/ynl/cli.py", line 69, in main
reply = ynl.dump(args.dump, attrs)
^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/donaldh/net-next/tools/net/ynl/lib/ynl.py", line 906, in dump
return self._op(method, vals, [], dump=True)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/donaldh/net-next/tools/net/ynl/lib/ynl.py", line 872, in _op
raise NlError(nl_msg)
lib.ynl.NlError: Netlink error: No such file or directory
nl_len = 44 (28) nl_flags = 0x300 nl_type = 2
error: -2 extack: {'bad-attr': '.op'}
Signed-off-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://lore.kernel.org/r/20240306231046.97158-3-donald.hunter@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Extack decoding was using a hard-coded msg header size of 20 but
netlink-raw has a header size of 16.
Use a protocol specific msghdr_size() when decoding the attr offssets.
Signed-off-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://lore.kernel.org/r/20240306231046.97158-2-donald.hunter@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Donald points out that we don't check for overflows.
Stash the length of the message on nlmsg_pid (nlmsg_seq would
do as well). This allows the attribute helpers to remain
self-contained (no extra arguments). Also let the put
helpers continue to return nothing. The error is checked
only in (newly introduced) ynl_msg_end().
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://lore.kernel.org/r/20240305185000.964773-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Most "production" netlink clients use large buffers to
make dump efficient, which means that handling of dump
continuation in the kernel is not very well tested.
Add an option for debugging / testing handling of dumps.
It enables printing of extra netlink-level debug and
lowers the recv() buffer size in one go. When used
without any argument (--dbg-small-recv) it picks
a very small default (4000), explicit size can be set,
too (--dbg-small-recv 5000).
Example:
$ ./cli.py [...] --dbg-small-recv
Recv: read 3712 bytes, 29 messages
nl_len = 128 (112) nl_flags = 0x0 nl_type = 19
[...]
nl_len = 128 (112) nl_flags = 0x0 nl_type = 19
Recv: read 3968 bytes, 31 messages
nl_len = 128 (112) nl_flags = 0x0 nl_type = 19
[...]
nl_len = 128 (112) nl_flags = 0x0 nl_type = 19
Recv: read 532 bytes, 5 messages
nl_len = 128 (112) nl_flags = 0x0 nl_type = 19
[...]
nl_len = 128 (112) nl_flags = 0x0 nl_type = 19
nl_len = 20 (4) nl_flags = 0x2 nl_type = 3
(the [...] are edits to shorten the commit message).
Note that the first message of the dump is sized conservatively
by the kernel.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
For manual debug, allow printing the netlink level messages
to stderr.
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Make the size of the buffer we use for recv() configurable.
The details of the buffer sizing in netlink are somewhat
arcane, we could spend a lot of time polishing this API.
Let's just leave some hopefully helpful comments for now.
This is a for-developers-only feature, anyway.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
