[PATCH wireguard v4 00/10] wireguard: netlink: ynl conversion

[PATCH wireguard v4 00/10] wireguard: netlink: ynl conversion

[Asbjørn Sloth Tønnesen]

This series completes the implementation of YNL for WireGuard,
as previously announced[1].

This series consist of 5 parts:
1) Patch 01-04 - Misc. changes
2) Patch    05 - Add YNL specification for wireguard
3) Patch 06-08 - Transition to a generated UAPI header
4) Patch    09 - Adds a sample program for the generated C library
5) Patch    10 - Transition to generated netlink policy code

The main benefit of having a YNL specification is unlocked after the
first 2 parts, the RFC version seems to already have spawned a new
Rust netlink binding[2] using wireguard as it's main example.

Part 3 and 5 validates that the specification is complete and aligned,
the generated code might have a few warts, but they don't matter too
much, and are mostly a transitional problem[3].

Part 4 is possible after part 2, but is ordered after part 3,
as it would otherwise have to update the header guard in Makefile.deps.

For the UAPI and non-generated kernel C code the diff stat looks like this:

$ git diff --stat wg-devel..wg-ynl include/ drivers/ \
	':(exclude)*generated/*'
 drivers/net/wireguard/Makefile  |   2 +-
 drivers/net/wireguard/netlink.c |  67 +++---------
 include/uapi/linux/wireguard.h  | 191 ++++++--------------------------
 3 files changed, 46 insertions(+), 214 deletions(-)

[1] [PATCH net 0/4] tools: ynl-gen: misc fixes + wireguard ynl plan
    https://lore.kernel.org/r/20250901145034.525518-1-ast@fiberby.net/
[2] https://github.com/one-d-wide/netlink-bindings/
[3] https://lore.kernel.org/r/20251014123201.6ecfd146@kernel.org/

---
v4:
- Thanks Jason and Jakub for all the feedback.
- Old patch 03 has been accepted into Jason's tree.
- Old patch 09 split_ops conversion has been moved to new 03.
- Old patch 10 function renaming was merged into old patch 11 (new 10).
- Patch 04 has been added to adjust .maxattr for GET_DEVICE.
- The old patches 04-08 and 11 was renumbered to patch 05-10.
- Changes to the spec:
  - Re-wrap the documentation lines in the spec.
  - Reword the index/type documentation.
  - get-device now have a more strict request attribute list.
  - The pre/post functions now avoids renaming.
- Changes to patch 10 (was 10+11):
  - The generated kernel code now uses YNL-ARG --function-prefix,
    to reduce the function renaming.
  - The generated files have been moved to their own sub-directory.
- The commit messages have in general been tweaked a bit.

v3: https://lore.kernel.org/r/20251105183223.89913-1-ast@fiberby.net/
- Spec: Make flags-mask checks implicit (thanks Jakub).
- Sample: Add header to Makefile.deps, and avoid copy (thanks Jakub).

v2: https://lore.kernel.org/r/20251031160539.1701943-1-ast@fiberby.net/
- Add missing forward declaration

v1: https://lore.kernel.org/r/20251029205123.286115-1-ast@fiberby.net/
- Policy arguement to nla_parse_nested() changed to NULL (thanks Johannes).
- Added attr-cnt-name to the spec, to reduce the diff a bit.
- Refined the doc in the spec a bit.
- Reword commit messages a bit.
- Reordered the patches, and reduced the series from 14 to 11 patches.

RFC: https://lore.kernel.org/r/20250904-wg-ynl-rfc@fiberby.net/

Asbjørn Sloth Tønnesen (10):
  wireguard: netlink: validate nested arrays in policy
  wireguard: netlink: use WG_KEY_LEN in policies
  wireguard: netlink: convert to split ops
  wireguard: netlink: lower .maxattr for WG_CMD_GET_DEVICE
  netlink: specs: add specification for wireguard
  wireguard: uapi: move enum wg_cmd
  wireguard: uapi: move flag enums
  wireguard: uapi: generate header with ynl-gen
  tools: ynl: add sample for wireguard
  wireguard: netlink: generate netlink code

 Documentation/netlink/specs/wireguard.yaml | 298 +++++++++++++++++++++
 MAINTAINERS                                |   2 +
 drivers/net/wireguard/Makefile             |   2 +-
 drivers/net/wireguard/generated/netlink.c  |  73 +++++
 drivers/net/wireguard/generated/netlink.h  |  30 +++
 drivers/net/wireguard/netlink.c            |  67 +----
 include/uapi/linux/wireguard.h             | 191 +++----------
 tools/net/ynl/Makefile.deps                |   2 +
 tools/net/ynl/samples/.gitignore           |   1 +
 tools/net/ynl/samples/wireguard.c          | 104 +++++++
 10 files changed, 556 insertions(+), 214 deletions(-)
 create mode 100644 Documentation/netlink/specs/wireguard.yaml
 create mode 100644 drivers/net/wireguard/generated/netlink.c
 create mode 100644 drivers/net/wireguard/generated/netlink.h
 create mode 100644 tools/net/ynl/samples/wireguard.c

-- 
2.51.0

[PATCH wireguard v4 01/10] wireguard: netlink: validate nested arrays in policy

[Asbjørn Sloth Tønnesen]

Use NLA_POLICY_NESTED_ARRAY() to perform nested array validation
in the policy validation step.

The nested policy was already enforced through nla_parse_nested(),
however extack wasn't passed previously, so no fancy error messages.

With the nested attributes being validated directly in the policy, the
policy argument can be set to NULL in the calls to nla_parse_nested().

Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
---
 drivers/net/wireguard/netlink.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireguard/netlink.c b/drivers/net/wireguard/netlink.c
index 8adeec6f94404..97723f9c7998f 100644
--- a/drivers/net/wireguard/netlink.c
+++ b/drivers/net/wireguard/netlink.c
@@ -18,6 +18,8 @@
 #include <crypto/utils.h>
 
 static struct genl_family genl_family;
+static const struct nla_policy peer_policy[WGPEER_A_MAX + 1];
+static const struct nla_policy allowedip_policy[WGALLOWEDIP_A_MAX + 1];
 
 static const struct nla_policy device_policy[WGDEVICE_A_MAX + 1] = {
 	[WGDEVICE_A_IFINDEX]		= { .type = NLA_U32 },
@@ -27,7 +29,7 @@ static const struct nla_policy device_policy[WGDEVICE_A_MAX + 1] = {
 	[WGDEVICE_A_FLAGS]		= NLA_POLICY_MASK(NLA_U32, __WGDEVICE_F_ALL),
 	[WGDEVICE_A_LISTEN_PORT]	= { .type = NLA_U16 },
 	[WGDEVICE_A_FWMARK]		= { .type = NLA_U32 },
-	[WGDEVICE_A_PEERS]		= { .type = NLA_NESTED }
+	[WGDEVICE_A_PEERS]		= NLA_POLICY_NESTED_ARRAY(peer_policy),
 };
 
 static const struct nla_policy peer_policy[WGPEER_A_MAX + 1] = {
@@ -39,7 +41,7 @@ static const struct nla_policy peer_policy[WGPEER_A_MAX + 1] = {
 	[WGPEER_A_LAST_HANDSHAKE_TIME]			= NLA_POLICY_EXACT_LEN(sizeof(struct __kernel_timespec)),
 	[WGPEER_A_RX_BYTES]				= { .type = NLA_U64 },
 	[WGPEER_A_TX_BYTES]				= { .type = NLA_U64 },
-	[WGPEER_A_ALLOWEDIPS]				= { .type = NLA_NESTED },
+	[WGPEER_A_ALLOWEDIPS]				= NLA_POLICY_NESTED_ARRAY(allowedip_policy),
 	[WGPEER_A_PROTOCOL_VERSION]			= { .type = NLA_U32 }
 };
 
@@ -467,7 +469,7 @@ static int set_peer(struct wg_device *wg, struct nlattr **attrs)
 
 		nla_for_each_nested(attr, attrs[WGPEER_A_ALLOWEDIPS], rem) {
 			ret = nla_parse_nested(allowedip, WGALLOWEDIP_A_MAX,
-					       attr, allowedip_policy, NULL);
+					       attr, NULL, NULL);
 			if (ret < 0)
 				goto out;
 			ret = set_allowedip(peer, allowedip);
@@ -593,7 +595,7 @@ static int wg_set_device(struct sk_buff *skb, struct genl_info *info)
 
 		nla_for_each_nested(attr, info->attrs[WGDEVICE_A_PEERS], rem) {
 			ret = nla_parse_nested(peer, WGPEER_A_MAX, attr,
-					       peer_policy, NULL);
+					       NULL, NULL);
 			if (ret < 0)
 				goto out;
 			ret = set_peer(wg, peer);
-- 
2.51.0

[PATCH wireguard v4 02/10] wireguard: netlink: use WG_KEY_LEN in policies

[Asbjørn Sloth Tønnesen]

When converting the netlink policies to YNL, the constants used
in the policy have to be visible to userspace.

As NOISE_*_KEY_LEN isn't visible to userspace, change the policy
to use WG_KEY_LEN, as also documented in the UAPI header:

$ grep WG_KEY_LEN include/uapi/linux/wireguard.h
 *    WGDEVICE_A_PRIVATE_KEY: NLA_EXACT_LEN, len WG_KEY_LEN
 *    WGDEVICE_A_PUBLIC_KEY: NLA_EXACT_LEN, len WG_KEY_LEN
 *            WGPEER_A_PUBLIC_KEY: NLA_EXACT_LEN, len WG_KEY_LEN
 *            WGPEER_A_PRESHARED_KEY: NLA_EXACT_LEN, len WG_KEY_LEN
 [...]

Add a couple of BUILD_BUG_ON() to ensure that they stay in sync.

No behavioural changes intended.

Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
---
 drivers/net/wireguard/netlink.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireguard/netlink.c b/drivers/net/wireguard/netlink.c
index 97723f9c7998f..682678d24a9f6 100644
--- a/drivers/net/wireguard/netlink.c
+++ b/drivers/net/wireguard/netlink.c
@@ -24,8 +24,8 @@ static const struct nla_policy allowedip_policy[WGALLOWEDIP_A_MAX + 1];
 static const struct nla_policy device_policy[WGDEVICE_A_MAX + 1] = {
 	[WGDEVICE_A_IFINDEX]		= { .type = NLA_U32 },
 	[WGDEVICE_A_IFNAME]		= { .type = NLA_NUL_STRING, .len = IFNAMSIZ - 1 },
-	[WGDEVICE_A_PRIVATE_KEY]	= NLA_POLICY_EXACT_LEN(NOISE_PUBLIC_KEY_LEN),
-	[WGDEVICE_A_PUBLIC_KEY]		= NLA_POLICY_EXACT_LEN(NOISE_PUBLIC_KEY_LEN),
+	[WGDEVICE_A_PRIVATE_KEY]	= NLA_POLICY_EXACT_LEN(WG_KEY_LEN),
+	[WGDEVICE_A_PUBLIC_KEY]		= NLA_POLICY_EXACT_LEN(WG_KEY_LEN),
 	[WGDEVICE_A_FLAGS]		= NLA_POLICY_MASK(NLA_U32, __WGDEVICE_F_ALL),
 	[WGDEVICE_A_LISTEN_PORT]	= { .type = NLA_U16 },
 	[WGDEVICE_A_FWMARK]		= { .type = NLA_U32 },
@@ -33,8 +33,8 @@ static const struct nla_policy device_policy[WGDEVICE_A_MAX + 1] = {
 };
 
 static const struct nla_policy peer_policy[WGPEER_A_MAX + 1] = {
-	[WGPEER_A_PUBLIC_KEY]				= NLA_POLICY_EXACT_LEN(NOISE_PUBLIC_KEY_LEN),
-	[WGPEER_A_PRESHARED_KEY]			= NLA_POLICY_EXACT_LEN(NOISE_SYMMETRIC_KEY_LEN),
+	[WGPEER_A_PUBLIC_KEY]				= NLA_POLICY_EXACT_LEN(WG_KEY_LEN),
+	[WGPEER_A_PRESHARED_KEY]			= NLA_POLICY_EXACT_LEN(WG_KEY_LEN),
 	[WGPEER_A_FLAGS]				= NLA_POLICY_MASK(NLA_U32, __WGPEER_F_ALL),
 	[WGPEER_A_ENDPOINT]				= NLA_POLICY_MIN_LEN(sizeof(struct sockaddr)),
 	[WGPEER_A_PERSISTENT_KEEPALIVE_INTERVAL]	= { .type = NLA_U16 },
@@ -643,6 +643,9 @@ static struct genl_family genl_family __ro_after_init = {
 
 int __init wg_genetlink_init(void)
 {
+	BUILD_BUG_ON(WG_KEY_LEN != NOISE_PUBLIC_KEY_LEN);
+	BUILD_BUG_ON(WG_KEY_LEN != NOISE_SYMMETRIC_KEY_LEN);
+
 	return genl_register_family(&genl_family);
 }
 
-- 
2.51.0

[PATCH wireguard v4 03/10] wireguard: netlink: convert to split ops

[Asbjørn Sloth Tønnesen]

This patch converts WireGuard from using the legacy struct genl_ops
to struct genl_split_ops, by applying the same transformation as
genl_cmd_full_to_split() would otherwise do at runtime.

WGDEVICE_A_MAX is swapped for WGDEVICE_A_PEERS, while they are
currently equivalent, then .maxattr should be the maximum attribute
that a given command supports, and not change along with WGDEVICE_A_MAX.

This is an incremental step towards adopting netlink policy code
generated by ynl-gen, ensuring that the code and spec is aligned.

This is a trivial patch with no behavioural changes intended.

Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
---
 drivers/net/wireguard/netlink.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/drivers/net/wireguard/netlink.c b/drivers/net/wireguard/netlink.c
index 682678d24a9f6..e7efe5f8465dc 100644
--- a/drivers/net/wireguard/netlink.c
+++ b/drivers/net/wireguard/netlink.c
@@ -616,28 +616,30 @@ static int wg_set_device(struct sk_buff *skb, struct genl_info *info)
 	return ret;
 }
 
-static const struct genl_ops genl_ops[] = {
+static const struct genl_split_ops wireguard_nl_ops[] = {
 	{
 		.cmd = WG_CMD_GET_DEVICE,
 		.start = wg_get_device_start,
 		.dumpit = wg_get_device_dump,
 		.done = wg_get_device_done,
-		.flags = GENL_UNS_ADMIN_PERM
+		.policy = device_policy,
+		.maxattr = WGDEVICE_A_PEERS,
+		.flags = GENL_UNS_ADMIN_PERM | GENL_CMD_CAP_DUMP,
 	}, {
 		.cmd = WG_CMD_SET_DEVICE,
 		.doit = wg_set_device,
-		.flags = GENL_UNS_ADMIN_PERM
+		.policy = device_policy,
+		.maxattr = WGDEVICE_A_PEERS,
+		.flags = GENL_UNS_ADMIN_PERM | GENL_CMD_CAP_DO,
 	}
 };
 
 static struct genl_family genl_family __ro_after_init = {
-	.ops = genl_ops,
-	.n_ops = ARRAY_SIZE(genl_ops),
+	.split_ops = wireguard_nl_ops,
+	.n_split_ops = ARRAY_SIZE(wireguard_nl_ops),
 	.name = WG_GENL_NAME,
 	.version = WG_GENL_VERSION,
-	.maxattr = WGDEVICE_A_MAX,
 	.module = THIS_MODULE,
-	.policy = device_policy,
 	.netnsok = true
 };
 
-- 
2.51.0

[PATCH wireguard v4 04/10] wireguard: netlink: lower .maxattr for WG_CMD_GET_DEVICE

[Asbjørn Sloth Tønnesen]

Previously .maxattr was shared for both WG_CMD_GET_DEVICE and
WG_CMD_SET_DEVICE. Now that it is split, then we can lower it
for WG_CMD_GET_DEVICE to follow the documentation which defines
.maxattr as WGDEVICE_A_IFNAME for WG_CMD_GET_DEVICE.

$ grep -hC5 'one but not both of:' include/uapi/linux/wireguard.h
 * WG_CMD_GET_DEVICE
 * -----------------
 *
 * May only be called via NLM_F_REQUEST | NLM_F_DUMP. The command
 * should contain one but not both of:
 *
 *    WGDEVICE_A_IFINDEX: NLA_U32
 *    WGDEVICE_A_IFNAME: NLA_NUL_STRING, maxlen IFNAMSIZ - 1
 *
 * The kernel will then return several messages [...]

While other attributes weren't rejected previously, the consensus
is that nobody sends those attributes, so nothing should break.

Link: https://lore.kernel.org/r/aRyLoy2iqbkUipZW@zx2c4.com/
Suggested-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
---
 drivers/net/wireguard/netlink.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireguard/netlink.c b/drivers/net/wireguard/netlink.c
index e7efe5f8465dc..c2d0576e96f5f 100644
--- a/drivers/net/wireguard/netlink.c
+++ b/drivers/net/wireguard/netlink.c
@@ -623,7 +623,7 @@ static const struct genl_split_ops wireguard_nl_ops[] = {
 		.dumpit = wg_get_device_dump,
 		.done = wg_get_device_done,
 		.policy = device_policy,
-		.maxattr = WGDEVICE_A_PEERS,
+		.maxattr = WGDEVICE_A_IFNAME,
 		.flags = GENL_UNS_ADMIN_PERM | GENL_CMD_CAP_DUMP,
 	}, {
 		.cmd = WG_CMD_SET_DEVICE,
-- 
2.51.0

[PATCH wireguard v4 05/10] netlink: specs: add specification for wireguard

[Asbjørn Sloth Tønnesen]

This patch adds a near[1] complete YNL specification for WireGuard,
documenting the protocol in a machine-readable format, rather than
comments in wireguard.h, and eases usage from C and non-C programming
languages alike.

The generated C library will be featured in a later patch, so in
this patch I will use the in-kernel python client for examples.

This makes the documentation in the UAPI header redundant, it is
therefore removed. The in-line documentation in the spec is based
on the existing comment in wireguard.h, and once released it will
be available in the kernel documentation at:
  https://docs.kernel.org/netlink/specs/wireguard.html
  (until then run: make htmldocs)

Generate wireguard.rst from this spec:
$ make -C tools/net/ynl/generated/ wireguard.rst

Query wireguard interface through pyynl:
$ sudo ./tools/net/ynl/pyynl/cli.py --family wireguard \
                                    --dump get-device \
                                    --json '{"ifindex":3}'
[{'fwmark': 0,
  'ifindex': 3,
  'ifname': 'wg-test',
  'listen-port': 54318,
  'peers': [{0: {'allowedips': [{0: {'cidr-mask': 0,
                                     'family': 2,
                                     'ipaddr': '0.0.0.0'}},
                                {0: {'cidr-mask': 0,
                                     'family': 10,
                                     'ipaddr': '::'}}],
                 'endpoint': b'[...]',
                 'last-handshake-time': {'nsec': 42, 'sec': 42},
                 'persistent-keepalive-interval': 42,
                 'preshared-key': '[...]',
                 'protocol-version': 1,
                 'public-key': '[...]',
                 'rx-bytes': 42,
                 'tx-bytes': 42}}],
  'private-key': '[...]',
  'public-key': '[...]'}]

Add another allowed IP prefix:
$ sudo ./tools/net/ynl/pyynl/cli.py --family wireguard \
  --do set-device --json '{"ifindex":3,"peers":[
    {"public-key":"6a df b1 83 a4 ..","allowedips":[
      {"cidr-mask":0,"family":10,"ipaddr":"::"}]}]}'

[1] As can be seen above, the "endpoint" is only dumped as binary data,
    as it can't be fully described in YNL. It's either a struct
    sockaddr_in or struct sockaddr_in6 depending on the attribute length.

Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
---
 Documentation/netlink/specs/wireguard.yaml | 298 +++++++++++++++++++++
 MAINTAINERS                                |   1 +
 include/uapi/linux/wireguard.h             | 129 ---------
 3 files changed, 299 insertions(+), 129 deletions(-)
 create mode 100644 Documentation/netlink/specs/wireguard.yaml

diff --git a/Documentation/netlink/specs/wireguard.yaml b/Documentation/netlink/specs/wireguard.yaml
new file mode 100644
index 0000000000000..30479fc6bb697
--- /dev/null
+++ b/Documentation/netlink/specs/wireguard.yaml
@@ -0,0 +1,298 @@
+# SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)
+---
+name: wireguard
+protocol: genetlink-legacy
+
+doc: |
+  **Netlink protocol to control WireGuard network devices.**
+
+  The below enums and macros are for interfacing with WireGuard, using generic
+  netlink, with family ``WG_GENL_NAME`` and version ``WG_GENL_VERSION``. It
+  defines two commands: get and set. Note that while they share many common
+  attributes, these two commands actually accept a slightly different set of
+  inputs and outputs. These differences are noted under the individual
+  attributes.
+c-family-name: wg-genl-name
+c-version-name: wg-genl-version
+max-by-define: true
+
+definitions:
+  -
+    name-prefix: wg-
+    name: key-len
+    type: const
+    value: 32
+  -
+    name: --kernel-timespec
+    type: struct
+    header: linux/time_types.h
+    members:
+      -
+        name: sec
+        type: u64
+        doc: Number of seconds, since UNIX epoch.
+      -
+        name: nsec
+        type: u64
+        doc: Number of nanoseconds, after the second began.
+  -
+    name: wgdevice-flags
+    name-prefix: wgdevice-f-
+    enum-name: wgdevice-flag
+    type: flags
+    entries:
+      - replace-peers
+  -
+    name: wgpeer-flags
+    name-prefix: wgpeer-f-
+    enum-name: wgpeer-flag
+    type: flags
+    entries:
+      - remove-me
+      - replace-allowedips
+      - update-only
+  -
+    name: wgallowedip-flags
+    name-prefix: wgallowedip-f-
+    enum-name: wgallowedip-flag
+    type: flags
+    entries:
+      - remove-me
+
+attribute-sets:
+  -
+    name: wgdevice
+    enum-name: wgdevice-attribute
+    name-prefix: wgdevice-a-
+    attr-cnt-name: --wgdevice-a-last
+    attributes:
+      -
+        name: unspec
+        type: unused
+        value: 0
+      -
+        name: ifindex
+        type: u32
+      -
+        name: ifname
+        type: string
+        checks:
+          max-len: 15
+      -
+        name: private-key
+        type: binary
+        doc: Set to all zeros to remove.
+        display-hint: hex
+        checks:
+          exact-len: wg-key-len
+      -
+        name: public-key
+        type: binary
+        display-hint: hex
+        checks:
+          exact-len: wg-key-len
+      -
+        name: flags
+        type: u32
+        doc: |
+          ``0`` or ``WGDEVICE_F_REPLACE_PEERS`` if all current peers should be
+          removed prior to adding the list below.
+        enum: wgdevice-flags
+      -
+        name: listen-port
+        type: u16
+        doc: Set as ``0`` to choose randomly.
+      -
+        name: fwmark
+        type: u32
+        doc: Set as ``0`` to disable.
+      -
+        name: peers
+        type: indexed-array
+        sub-type: nest
+        nested-attributes: wgpeer
+        doc: |
+          The index/type parameter is unused on ``SET_DEVICE`` operations and is
+          zero on ``GET_DEVICE`` operations.
+  -
+    name: wgpeer
+    enum-name: wgpeer-attribute
+    name-prefix: wgpeer-a-
+    attr-cnt-name: --wgpeer-a-last
+    attributes:
+      -
+        name: unspec
+        type: unused
+        value: 0
+      -
+        name: public-key
+        type: binary
+        display-hint: hex
+        checks:
+          exact-len: wg-key-len
+      -
+        name: preshared-key
+        type: binary
+        doc: Set as all zeros to remove.
+        display-hint: hex
+        checks:
+          exact-len: wg-key-len
+      -
+        name: flags
+        type: u32
+        doc: |
+          ``0`` and/or ``WGPEER_F_REMOVE_ME`` if the specified peer should not
+          exist at the end of the operation, rather than added/updated and/or
+          ``WGPEER_F_REPLACE_ALLOWEDIPS`` if all current allowed IPs of this
+          peer should be removed prior to adding the list below and/or
+          ``WGPEER_F_UPDATE_ONLY`` if the peer should only be set if it already
+          exists.
+        enum: wgpeer-flags
+      -
+        name: endpoint
+        type: binary
+        doc: struct sockaddr_in or struct sockaddr_in6
+        checks:
+          min-len: 16
+      -
+        name: persistent-keepalive-interval
+        type: u16
+        doc: Set as ``0`` to disable.
+      -
+        name: last-handshake-time
+        type: binary
+        struct: --kernel-timespec
+        checks:
+          exact-len: 16
+      -
+        name: rx-bytes
+        type: u64
+      -
+        name: tx-bytes
+        type: u64
+      -
+        name: allowedips
+        type: indexed-array
+        sub-type: nest
+        nested-attributes: wgallowedip
+        doc: |
+          The index/type parameter is unused on ``SET_DEVICE`` operations and is
+          zero on ``GET_DEVICE`` operations.
+      -
+        name: protocol-version
+        type: u32
+        doc: |
+          Should not be set or used at all by most users of this API, as the
+          most recent protocol will be used when this is unset. Otherwise,
+          must be set to ``1``.
+  -
+    name: wgallowedip
+    enum-name: wgallowedip-attribute
+    name-prefix: wgallowedip-a-
+    attr-cnt-name: --wgallowedip-a-last
+    attributes:
+      -
+        name: unspec
+        type: unused
+        value: 0
+      -
+        name: family
+        type: u16
+        doc: IP family, either ``AF_INET`` or ``AF_INET6``.
+      -
+        name: ipaddr
+        type: binary
+        doc: Either ``struct in_addr`` or ``struct in6_addr``.
+        display-hint: ipv4-or-v6
+        checks:
+          min-len: 4
+      -
+        name: cidr-mask
+        type: u8
+      -
+        name: flags
+        type: u32
+        doc: |
+          ``WGALLOWEDIP_F_REMOVE_ME`` if the specified IP should be removed;
+          otherwise, this IP will be added if it is not already present.
+        enum: wgallowedip-flags
+
+operations:
+  enum-name: wg-cmd
+  name-prefix: wg-cmd-
+  list:
+    -
+      name: get-device
+      value: 0
+      doc: |
+        Retrieve WireGuard device
+        ~~~~~~~~~~~~~~~~~~~~~~~~~
+
+        The command should be called with one but not both of:
+
+        - ``WGDEVICE_A_IFINDEX``
+        - ``WGDEVICE_A_IFNAME``
+
+        The kernel will then return several messages (``NLM_F_MULTI``). It is
+        possible that all of the allowed IPs of a single peer will not fit
+        within a single netlink message. In that case, the same peer will be
+        written in the following message, except it will only contain
+        ``WGPEER_A_PUBLIC_KEY`` and ``WGPEER_A_ALLOWEDIPS``. This may occur
+        several times in a row for the same peer. It is then up to the receiver
+        to coalesce adjacent peers. Likewise, it is possible that all peers will
+        not fit within a single message. So, subsequent peers will be sent in
+        following messages, except those will only contain ``WGDEVICE_A_IFNAME``
+        and ``WGDEVICE_A_PEERS``. It is then up to the receiver to coalesce
+        these messages to form the complete list of peers.
+
+        Since this is an ``NLA_F_DUMP`` command, the final message will always
+        be ``NLMSG_DONE``, even if an error occurs. However, this ``NLMSG_DONE``
+        message contains an integer error code. It is either zero or a negative
+        error code corresponding to the errno.
+      attribute-set: wgdevice
+      flags: [uns-admin-perm]
+
+      dump:
+        pre: wg-get-device-start
+        post: wg-get-device-done
+        request:
+          attributes:
+            - ifindex
+            - ifname
+        reply: &all-attrs
+          attributes:
+            - ifindex
+            - ifname
+            - private-key
+            - public-key
+            - flags
+            - listen-port
+            - fwmark
+            - peers
+    -
+      name: set-device
+      value: 1
+      doc: |
+        Set WireGuard device
+        ~~~~~~~~~~~~~~~~~~~~
+
+        This command should be called with a wgdevice set, containing one but
+        not both of ``WGDEVICE_A_IFINDEX`` and ``WGDEVICE_A_IFNAME``.
+
+        It is possible that the amount of configuration data exceeds that of the
+        maximum message length accepted by the kernel. In that case, several
+        messages should be sent one after another, with each successive one
+        filling in information not contained in the prior. Note that if
+        ``WGDEVICE_F_REPLACE_PEERS`` is specified in the first message, it
+        probably should not be specified in fragments that come after, so that
+        the list of peers is only cleared the first time but appended after.
+        Likewise for peers, if ``WGPEER_F_REPLACE_ALLOWEDIPS`` is specified in
+        the first message of a peer, it likely should not be specified in
+        subsequent fragments.
+
+        If an error occurs, ``NLMSG_ERROR`` will reply containing an errno.
+      attribute-set: wgdevice
+      flags: [uns-admin-perm]
+
+      do:
+        request: *all-attrs
diff --git a/MAINTAINERS b/MAINTAINERS
index e9a8d945632bf..a72fe5ce334b6 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -27663,6 +27663,7 @@ M:	Jason A. Donenfeld <Jason@zx2c4.com>
 L:	wireguard@lists.zx2c4.com
 L:	netdev@vger.kernel.org
 S:	Maintained
+F:	Documentation/netlink/specs/wireguard.yaml
 F:	drivers/net/wireguard/
 F:	tools/testing/selftests/wireguard/
 
diff --git a/include/uapi/linux/wireguard.h b/include/uapi/linux/wireguard.h
index 8c26391196d50..dee4401e0b5df 100644
--- a/include/uapi/linux/wireguard.h
+++ b/include/uapi/linux/wireguard.h
@@ -1,135 +1,6 @@
 /* SPDX-License-Identifier: (GPL-2.0 WITH Linux-syscall-note) OR MIT */
 /*
  * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
- *
- * Documentation
- * =============
- *
- * The below enums and macros are for interfacing with WireGuard, using generic
- * netlink, with family WG_GENL_NAME and version WG_GENL_VERSION. It defines two
- * methods: get and set. Note that while they share many common attributes,
- * these two functions actually accept a slightly different set of inputs and
- * outputs.
- *
- * WG_CMD_GET_DEVICE
- * -----------------
- *
- * May only be called via NLM_F_REQUEST | NLM_F_DUMP. The command should contain
- * one but not both of:
- *
- *    WGDEVICE_A_IFINDEX: NLA_U32
- *    WGDEVICE_A_IFNAME: NLA_NUL_STRING, maxlen IFNAMSIZ - 1
- *
- * The kernel will then return several messages (NLM_F_MULTI) containing the
- * following tree of nested items:
- *
- *    WGDEVICE_A_IFINDEX: NLA_U32
- *    WGDEVICE_A_IFNAME: NLA_NUL_STRING, maxlen IFNAMSIZ - 1
- *    WGDEVICE_A_PRIVATE_KEY: NLA_EXACT_LEN, len WG_KEY_LEN
- *    WGDEVICE_A_PUBLIC_KEY: NLA_EXACT_LEN, len WG_KEY_LEN
- *    WGDEVICE_A_LISTEN_PORT: NLA_U16
- *    WGDEVICE_A_FWMARK: NLA_U32
- *    WGDEVICE_A_PEERS: NLA_NESTED
- *        0: NLA_NESTED
- *            WGPEER_A_PUBLIC_KEY: NLA_EXACT_LEN, len WG_KEY_LEN
- *            WGPEER_A_PRESHARED_KEY: NLA_EXACT_LEN, len WG_KEY_LEN
- *            WGPEER_A_ENDPOINT: NLA_MIN_LEN(struct sockaddr), struct sockaddr_in or struct sockaddr_in6
- *            WGPEER_A_PERSISTENT_KEEPALIVE_INTERVAL: NLA_U16
- *            WGPEER_A_LAST_HANDSHAKE_TIME: NLA_EXACT_LEN, struct __kernel_timespec
- *            WGPEER_A_RX_BYTES: NLA_U64
- *            WGPEER_A_TX_BYTES: NLA_U64
- *            WGPEER_A_ALLOWEDIPS: NLA_NESTED
- *                0: NLA_NESTED
- *                    WGALLOWEDIP_A_FAMILY: NLA_U16
- *                    WGALLOWEDIP_A_IPADDR: NLA_MIN_LEN(struct in_addr), struct in_addr or struct in6_addr
- *                    WGALLOWEDIP_A_CIDR_MASK: NLA_U8
- *                0: NLA_NESTED
- *                    ...
- *                0: NLA_NESTED
- *                    ...
- *                ...
- *            WGPEER_A_PROTOCOL_VERSION: NLA_U32
- *        0: NLA_NESTED
- *            ...
- *        ...
- *
- * It is possible that all of the allowed IPs of a single peer will not
- * fit within a single netlink message. In that case, the same peer will
- * be written in the following message, except it will only contain
- * WGPEER_A_PUBLIC_KEY and WGPEER_A_ALLOWEDIPS. This may occur several
- * times in a row for the same peer. It is then up to the receiver to
- * coalesce adjacent peers. Likewise, it is possible that all peers will
- * not fit within a single message. So, subsequent peers will be sent
- * in following messages, except those will only contain WGDEVICE_A_IFNAME
- * and WGDEVICE_A_PEERS. It is then up to the receiver to coalesce these
- * messages to form the complete list of peers.
- *
- * Since this is an NLA_F_DUMP command, the final message will always be
- * NLMSG_DONE, even if an error occurs. However, this NLMSG_DONE message
- * contains an integer error code. It is either zero or a negative error
- * code corresponding to the errno.
- *
- * WG_CMD_SET_DEVICE
- * -----------------
- *
- * May only be called via NLM_F_REQUEST. The command should contain the
- * following tree of nested items, containing one but not both of
- * WGDEVICE_A_IFINDEX and WGDEVICE_A_IFNAME:
- *
- *    WGDEVICE_A_IFINDEX: NLA_U32
- *    WGDEVICE_A_IFNAME: NLA_NUL_STRING, maxlen IFNAMSIZ - 1
- *    WGDEVICE_A_FLAGS: NLA_U32, 0 or WGDEVICE_F_REPLACE_PEERS if all current
- *                      peers should be removed prior to adding the list below.
- *    WGDEVICE_A_PRIVATE_KEY: len WG_KEY_LEN, all zeros to remove
- *    WGDEVICE_A_LISTEN_PORT: NLA_U16, 0 to choose randomly
- *    WGDEVICE_A_FWMARK: NLA_U32, 0 to disable
- *    WGDEVICE_A_PEERS: NLA_NESTED
- *        0: NLA_NESTED
- *            WGPEER_A_PUBLIC_KEY: len WG_KEY_LEN
- *            WGPEER_A_FLAGS: NLA_U32, 0 and/or WGPEER_F_REMOVE_ME if the
- *                            specified peer should not exist at the end of the
- *                            operation, rather than added/updated and/or
- *                            WGPEER_F_REPLACE_ALLOWEDIPS if all current allowed
- *                            IPs of this peer should be removed prior to adding
- *                            the list below and/or WGPEER_F_UPDATE_ONLY if the
- *                            peer should only be set if it already exists.
- *            WGPEER_A_PRESHARED_KEY: len WG_KEY_LEN, all zeros to remove
- *            WGPEER_A_ENDPOINT: struct sockaddr_in or struct sockaddr_in6
- *            WGPEER_A_PERSISTENT_KEEPALIVE_INTERVAL: NLA_U16, 0 to disable
- *            WGPEER_A_ALLOWEDIPS: NLA_NESTED
- *                0: NLA_NESTED
- *                    WGALLOWEDIP_A_FAMILY: NLA_U16
- *                    WGALLOWEDIP_A_IPADDR: struct in_addr or struct in6_addr
- *                    WGALLOWEDIP_A_CIDR_MASK: NLA_U8
- *                    WGALLOWEDIP_A_FLAGS: NLA_U32, WGALLOWEDIP_F_REMOVE_ME if
- *                                         the specified IP should be removed;
- *                                         otherwise, this IP will be added if
- *                                         it is not already present.
- *                0: NLA_NESTED
- *                    ...
- *                0: NLA_NESTED
- *                    ...
- *                ...
- *            WGPEER_A_PROTOCOL_VERSION: NLA_U32, should not be set or used at
- *                                       all by most users of this API, as the
- *                                       most recent protocol will be used when
- *                                       this is unset. Otherwise, must be set
- *                                       to 1.
- *        0: NLA_NESTED
- *            ...
- *        ...
- *
- * It is possible that the amount of configuration data exceeds that of
- * the maximum message length accepted by the kernel. In that case, several
- * messages should be sent one after another, with each successive one
- * filling in information not contained in the prior. Note that if
- * WGDEVICE_F_REPLACE_PEERS is specified in the first message, it probably
- * should not be specified in fragments that come after, so that the list
- * of peers is only cleared the first time but appended after. Likewise for
- * peers, if WGPEER_F_REPLACE_ALLOWEDIPS is specified in the first message
- * of a peer, it likely should not be specified in subsequent fragments.
- *
- * If an error occurs, NLMSG_ERROR will reply containing an errno.
  */
 
 #ifndef _WG_UAPI_WIREGUARD_H
-- 
2.51.0

[PATCH wireguard v4 06/10] wireguard: uapi: move enum wg_cmd

[Asbjørn Sloth Tønnesen]

This patch moves enum wg_cmd to the end of the file, where ynl-gen
would generate it.

This is an incremental step towards adopting an UAPI header generated
by ynl-gen. This is split out to keep the patches readable.

This is a trivial patch with no behavioural changes intended.

Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
---
 include/uapi/linux/wireguard.h | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/include/uapi/linux/wireguard.h b/include/uapi/linux/wireguard.h
index dee4401e0b5df..3ebfffd61269a 100644
--- a/include/uapi/linux/wireguard.h
+++ b/include/uapi/linux/wireguard.h
@@ -11,13 +11,6 @@
 
 #define WG_KEY_LEN 32
 
-enum wg_cmd {
-	WG_CMD_GET_DEVICE,
-	WG_CMD_SET_DEVICE,
-	__WG_CMD_MAX
-};
-#define WG_CMD_MAX (__WG_CMD_MAX - 1)
-
 enum wgdevice_flag {
 	WGDEVICE_F_REPLACE_PEERS = 1U << 0,
 	__WGDEVICE_F_ALL = WGDEVICE_F_REPLACE_PEERS
@@ -73,4 +66,12 @@ enum wgallowedip_attribute {
 };
 #define WGALLOWEDIP_A_MAX (__WGALLOWEDIP_A_LAST - 1)
 
+enum wg_cmd {
+	WG_CMD_GET_DEVICE,
+	WG_CMD_SET_DEVICE,
+
+	__WG_CMD_MAX
+};
+#define WG_CMD_MAX (__WG_CMD_MAX - 1)
+
 #endif /* _WG_UAPI_WIREGUARD_H */
-- 
2.51.0

[PATCH wireguard v4 07/10] wireguard: uapi: move flag enums

[Asbjørn Sloth Tønnesen]

Move the wg*_flag enums, so they are defined above the attribute set
enums, where ynl-gen would place them.

This is an incremental step towards adopting an UAPI header generated
by ynl-gen. This is split out to keep the patches readable.

This is a trivial patch with no behavioural changes intended.

Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
---
 include/uapi/linux/wireguard.h | 25 ++++++++++++++-----------
 1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/include/uapi/linux/wireguard.h b/include/uapi/linux/wireguard.h
index 3ebfffd61269a..a2815f4f29104 100644
--- a/include/uapi/linux/wireguard.h
+++ b/include/uapi/linux/wireguard.h
@@ -15,6 +15,20 @@ enum wgdevice_flag {
 	WGDEVICE_F_REPLACE_PEERS = 1U << 0,
 	__WGDEVICE_F_ALL = WGDEVICE_F_REPLACE_PEERS
 };
+
+enum wgpeer_flag {
+	WGPEER_F_REMOVE_ME = 1U << 0,
+	WGPEER_F_REPLACE_ALLOWEDIPS = 1U << 1,
+	WGPEER_F_UPDATE_ONLY = 1U << 2,
+	__WGPEER_F_ALL = WGPEER_F_REMOVE_ME | WGPEER_F_REPLACE_ALLOWEDIPS |
+			 WGPEER_F_UPDATE_ONLY
+};
+
+enum wgallowedip_flag {
+	WGALLOWEDIP_F_REMOVE_ME = 1U << 0,
+	__WGALLOWEDIP_F_ALL = WGALLOWEDIP_F_REMOVE_ME
+};
+
 enum wgdevice_attribute {
 	WGDEVICE_A_UNSPEC,
 	WGDEVICE_A_IFINDEX,
@@ -29,13 +43,6 @@ enum wgdevice_attribute {
 };
 #define WGDEVICE_A_MAX (__WGDEVICE_A_LAST - 1)
 
-enum wgpeer_flag {
-	WGPEER_F_REMOVE_ME = 1U << 0,
-	WGPEER_F_REPLACE_ALLOWEDIPS = 1U << 1,
-	WGPEER_F_UPDATE_ONLY = 1U << 2,
-	__WGPEER_F_ALL = WGPEER_F_REMOVE_ME | WGPEER_F_REPLACE_ALLOWEDIPS |
-			 WGPEER_F_UPDATE_ONLY
-};
 enum wgpeer_attribute {
 	WGPEER_A_UNSPEC,
 	WGPEER_A_PUBLIC_KEY,
@@ -52,10 +59,6 @@ enum wgpeer_attribute {
 };
 #define WGPEER_A_MAX (__WGPEER_A_LAST - 1)
 
-enum wgallowedip_flag {
-	WGALLOWEDIP_F_REMOVE_ME = 1U << 0,
-	__WGALLOWEDIP_F_ALL = WGALLOWEDIP_F_REMOVE_ME
-};
 enum wgallowedip_attribute {
 	WGALLOWEDIP_A_UNSPEC,
 	WGALLOWEDIP_A_FAMILY,
-- 
2.51.0

[PATCH wireguard v4 08/10] wireguard: uapi: generate header with ynl-gen

[Asbjørn Sloth Tønnesen]

Use ynl-gen to generate the UAPI header for WireGuard.

The cosmetic changes in this patch confirms that the spec is aligned
with the implementation. By using the generated version, it ensures
that they stay in sync.

Changes in the generated header:
* Trivial header guard rename.
* Trivial white space changes.
* Trivial comment changes.
* Precompute bitflags in ynl-gen (see [1]).
* Drop __*_F_ALL constants (see [1]).

[1] https://lore.kernel.org/r/20251014123201.6ecfd146@kernel.org/

No behavioural changes intended.

Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
---
 drivers/net/wireguard/netlink.c |  6 +++---
 include/uapi/linux/wireguard.h  | 38 ++++++++++++++++-----------------
 2 files changed, 22 insertions(+), 22 deletions(-)

diff --git a/drivers/net/wireguard/netlink.c b/drivers/net/wireguard/netlink.c
index c2d0576e96f5f..0ce0bda8c1ce8 100644
--- a/drivers/net/wireguard/netlink.c
+++ b/drivers/net/wireguard/netlink.c
@@ -26,7 +26,7 @@ static const struct nla_policy device_policy[WGDEVICE_A_MAX + 1] = {
 	[WGDEVICE_A_IFNAME]		= { .type = NLA_NUL_STRING, .len = IFNAMSIZ - 1 },
 	[WGDEVICE_A_PRIVATE_KEY]	= NLA_POLICY_EXACT_LEN(WG_KEY_LEN),
 	[WGDEVICE_A_PUBLIC_KEY]		= NLA_POLICY_EXACT_LEN(WG_KEY_LEN),
-	[WGDEVICE_A_FLAGS]		= NLA_POLICY_MASK(NLA_U32, __WGDEVICE_F_ALL),
+	[WGDEVICE_A_FLAGS]		= NLA_POLICY_MASK(NLA_U32, 0x1),
 	[WGDEVICE_A_LISTEN_PORT]	= { .type = NLA_U16 },
 	[WGDEVICE_A_FWMARK]		= { .type = NLA_U32 },
 	[WGDEVICE_A_PEERS]		= NLA_POLICY_NESTED_ARRAY(peer_policy),
@@ -35,7 +35,7 @@ static const struct nla_policy device_policy[WGDEVICE_A_MAX + 1] = {
 static const struct nla_policy peer_policy[WGPEER_A_MAX + 1] = {
 	[WGPEER_A_PUBLIC_KEY]				= NLA_POLICY_EXACT_LEN(WG_KEY_LEN),
 	[WGPEER_A_PRESHARED_KEY]			= NLA_POLICY_EXACT_LEN(WG_KEY_LEN),
-	[WGPEER_A_FLAGS]				= NLA_POLICY_MASK(NLA_U32, __WGPEER_F_ALL),
+	[WGPEER_A_FLAGS]				= NLA_POLICY_MASK(NLA_U32, 0x7),
 	[WGPEER_A_ENDPOINT]				= NLA_POLICY_MIN_LEN(sizeof(struct sockaddr)),
 	[WGPEER_A_PERSISTENT_KEEPALIVE_INTERVAL]	= { .type = NLA_U16 },
 	[WGPEER_A_LAST_HANDSHAKE_TIME]			= NLA_POLICY_EXACT_LEN(sizeof(struct __kernel_timespec)),
@@ -49,7 +49,7 @@ static const struct nla_policy allowedip_policy[WGALLOWEDIP_A_MAX + 1] = {
 	[WGALLOWEDIP_A_FAMILY]		= { .type = NLA_U16 },
 	[WGALLOWEDIP_A_IPADDR]		= NLA_POLICY_MIN_LEN(sizeof(struct in_addr)),
 	[WGALLOWEDIP_A_CIDR_MASK]	= { .type = NLA_U8 },
-	[WGALLOWEDIP_A_FLAGS]		= NLA_POLICY_MASK(NLA_U32, __WGALLOWEDIP_F_ALL),
+	[WGALLOWEDIP_A_FLAGS]		= NLA_POLICY_MASK(NLA_U32, 0x1),
 };
 
 static struct wg_device *lookup_interface(struct nlattr **attrs,
diff --git a/include/uapi/linux/wireguard.h b/include/uapi/linux/wireguard.h
index a2815f4f29104..a100b9715b083 100644
--- a/include/uapi/linux/wireguard.h
+++ b/include/uapi/linux/wireguard.h
@@ -1,32 +1,29 @@
-/* SPDX-License-Identifier: (GPL-2.0 WITH Linux-syscall-note) OR MIT */
-/*
- * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
- */
+/* SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) */
+/* Do not edit directly, auto-generated from: */
+/*	Documentation/netlink/specs/wireguard.yaml */
+/* YNL-GEN uapi header */
+/* To regenerate run: tools/net/ynl/ynl-regen.sh */
 
-#ifndef _WG_UAPI_WIREGUARD_H
-#define _WG_UAPI_WIREGUARD_H
+#ifndef _UAPI_LINUX_WIREGUARD_H
+#define _UAPI_LINUX_WIREGUARD_H
 
-#define WG_GENL_NAME "wireguard"
-#define WG_GENL_VERSION 1
+#define WG_GENL_NAME	"wireguard"
+#define WG_GENL_VERSION	1
 
-#define WG_KEY_LEN 32
+#define WG_KEY_LEN	32
 
 enum wgdevice_flag {
-	WGDEVICE_F_REPLACE_PEERS = 1U << 0,
-	__WGDEVICE_F_ALL = WGDEVICE_F_REPLACE_PEERS
+	WGDEVICE_F_REPLACE_PEERS = 1,
 };
 
 enum wgpeer_flag {
-	WGPEER_F_REMOVE_ME = 1U << 0,
-	WGPEER_F_REPLACE_ALLOWEDIPS = 1U << 1,
-	WGPEER_F_UPDATE_ONLY = 1U << 2,
-	__WGPEER_F_ALL = WGPEER_F_REMOVE_ME | WGPEER_F_REPLACE_ALLOWEDIPS |
-			 WGPEER_F_UPDATE_ONLY
+	WGPEER_F_REMOVE_ME = 1,
+	WGPEER_F_REPLACE_ALLOWEDIPS = 2,
+	WGPEER_F_UPDATE_ONLY = 4,
 };
 
 enum wgallowedip_flag {
-	WGALLOWEDIP_F_REMOVE_ME = 1U << 0,
-	__WGALLOWEDIP_F_ALL = WGALLOWEDIP_F_REMOVE_ME
+	WGALLOWEDIP_F_REMOVE_ME = 1,
 };
 
 enum wgdevice_attribute {
@@ -39,6 +36,7 @@ enum wgdevice_attribute {
 	WGDEVICE_A_LISTEN_PORT,
 	WGDEVICE_A_FWMARK,
 	WGDEVICE_A_PEERS,
+
 	__WGDEVICE_A_LAST
 };
 #define WGDEVICE_A_MAX (__WGDEVICE_A_LAST - 1)
@@ -55,6 +53,7 @@ enum wgpeer_attribute {
 	WGPEER_A_TX_BYTES,
 	WGPEER_A_ALLOWEDIPS,
 	WGPEER_A_PROTOCOL_VERSION,
+
 	__WGPEER_A_LAST
 };
 #define WGPEER_A_MAX (__WGPEER_A_LAST - 1)
@@ -65,6 +64,7 @@ enum wgallowedip_attribute {
 	WGALLOWEDIP_A_IPADDR,
 	WGALLOWEDIP_A_CIDR_MASK,
 	WGALLOWEDIP_A_FLAGS,
+
 	__WGALLOWEDIP_A_LAST
 };
 #define WGALLOWEDIP_A_MAX (__WGALLOWEDIP_A_LAST - 1)
@@ -77,4 +77,4 @@ enum wg_cmd {
 };
 #define WG_CMD_MAX (__WG_CMD_MAX - 1)
 
-#endif /* _WG_UAPI_WIREGUARD_H */
+#endif /* _UAPI_LINUX_WIREGUARD_H */
-- 
2.51.0

[PATCH wireguard v4 09/10] tools: ynl: add sample for wireguard

[Asbjørn Sloth Tønnesen]

Add a sample application for WireGuard, using the generated C library.

The main benefit of this is to exercise the generated library,
which might be useful for future selftests.

In order to support usage with a pre-YNL wireguard.h in /usr/include,
the former header guard is added to Makefile.deps as well.

Example:
  $ make -C tools/net/ynl/lib
  $ make -C tools/net/ynl/generated
  $ make -C tools/net/ynl/samples wireguard
  $ ./tools/net/ynl/samples/wireguard
  usage: ./tools/net/ynl/samples/wireguard <ifindex|ifname>
  $ sudo ./tools/net/ynl/samples/wireguard wg-test
  Interface 3: wg-test
      Peer 6adfb183a4a2c94a2f92dab5ade762a4788[...]:
          Data: rx: 42 / tx: 42 bytes
          Allowed IPs:
              0.0.0.0/0
              ::/0

Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
---
 MAINTAINERS                       |   1 +
 tools/net/ynl/Makefile.deps       |   2 +
 tools/net/ynl/samples/.gitignore  |   1 +
 tools/net/ynl/samples/wireguard.c | 104 ++++++++++++++++++++++++++++++
 4 files changed, 108 insertions(+)
 create mode 100644 tools/net/ynl/samples/wireguard.c

diff --git a/MAINTAINERS b/MAINTAINERS
index a72fe5ce334b6..dfc7b7a017561 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -27665,6 +27665,7 @@ L:	netdev@vger.kernel.org
 S:	Maintained
 F:	Documentation/netlink/specs/wireguard.yaml
 F:	drivers/net/wireguard/
+F:	tools/net/ynl/samples/wireguard.c
 F:	tools/testing/selftests/wireguard/
 
 WISTRON LAPTOP BUTTON DRIVER
diff --git a/tools/net/ynl/Makefile.deps b/tools/net/ynl/Makefile.deps
index 865fd2e8519ed..a9a5348b31a3b 100644
--- a/tools/net/ynl/Makefile.deps
+++ b/tools/net/ynl/Makefile.deps
@@ -48,3 +48,5 @@ CFLAGS_tc:= $(call get_hdr_inc,__LINUX_RTNETLINK_H,rtnetlink.h) \
 	$(call get_hdr_inc,_TC_SKBEDIT_H,tc_act/tc_skbedit.h) \
 	$(call get_hdr_inc,_TC_TUNNEL_KEY_H,tc_act/tc_tunnel_key.h)
 CFLAGS_tcp_metrics:=$(call get_hdr_inc,_LINUX_TCP_METRICS_H,tcp_metrics.h)
+CFLAGS_wireguard:=$(call get_hdr_inc,_LINUX_WIREGUARD_H,wireguard.h) \
+	-D _WG_UAPI_WIREGUARD_H # alternate pre-YNL guard
diff --git a/tools/net/ynl/samples/.gitignore b/tools/net/ynl/samples/.gitignore
index 05087ee323ba2..6fbed294feac0 100644
--- a/tools/net/ynl/samples/.gitignore
+++ b/tools/net/ynl/samples/.gitignore
@@ -8,3 +8,4 @@ rt-link
 rt-route
 tc
 tc-filter-add
+wireguard
diff --git a/tools/net/ynl/samples/wireguard.c b/tools/net/ynl/samples/wireguard.c
new file mode 100644
index 0000000000000..43f3551eb101a
--- /dev/null
+++ b/tools/net/ynl/samples/wireguard.c
@@ -0,0 +1,104 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <arpa/inet.h>
+#include <string.h>
+#include <stdio.h>
+#include <errno.h>
+#include <ynl.h>
+
+#include "wireguard-user.h"
+
+static void print_allowed_ip(const struct wireguard_wgallowedip *aip)
+{
+	char addr_out[INET6_ADDRSTRLEN];
+
+	if (!inet_ntop(aip->family, aip->ipaddr, addr_out, sizeof(addr_out))) {
+		addr_out[0] = '?';
+		addr_out[1] = '\0';
+	}
+	printf("\t\t\t%s/%u\n", addr_out, aip->cidr_mask);
+}
+
+/* Only printing public key in this demo. For better key formatting,
+ * use the constant-time implementation as found in wireguard-tools.
+ */
+static void print_peer_header(const struct wireguard_wgpeer *peer)
+{
+	unsigned int i;
+	uint8_t *key = peer->public_key;
+	unsigned int len = peer->_len.public_key;
+
+	if (len != 32)
+		return;
+	printf("\tPeer ");
+	for (i = 0; i < len; i++)
+		printf("%02x", key[i]);
+	printf(":\n");
+}
+
+static void print_peer(const struct wireguard_wgpeer *peer)
+{
+	unsigned int i;
+
+	print_peer_header(peer);
+	printf("\t\tData: rx: %llu / tx: %llu bytes\n",
+	       peer->rx_bytes, peer->tx_bytes);
+	printf("\t\tAllowed IPs:\n");
+	for (i = 0; i < peer->_count.allowedips; i++)
+		print_allowed_ip(&peer->allowedips[i]);
+}
+
+static void build_request(struct wireguard_get_device_req *req, char *arg)
+{
+	char *endptr;
+	int ifindex;
+
+	ifindex = strtol(arg, &endptr, 0);
+	if (endptr != arg + strlen(arg) || errno != 0)
+		ifindex = 0;
+	if (ifindex > 0)
+		wireguard_get_device_req_set_ifindex(req, ifindex);
+	else
+		wireguard_get_device_req_set_ifname(req, arg);
+}
+
+int main(int argc, char **argv)
+{
+	struct wireguard_get_device_list *devs;
+	struct wireguard_get_device_req *req;
+	struct ynl_sock *ys;
+
+	if (argc < 2) {
+		fprintf(stderr, "usage: %s <ifindex|ifname>\n", argv[0]);
+		return 1;
+	}
+
+	req = wireguard_get_device_req_alloc();
+	build_request(req, argv[1]);
+
+	ys = ynl_sock_create(&ynl_wireguard_family, NULL);
+	if (!ys)
+		return 2;
+
+	devs = wireguard_get_device_dump(ys, req);
+	if (!devs)
+		goto err_close;
+
+	ynl_dump_foreach(devs, d) {
+		unsigned int i;
+
+		printf("Interface %d: %s\n", d->ifindex, d->ifname);
+		for (i = 0; i < d->_count.peers; i++)
+			print_peer(&d->peers[i]);
+	}
+	wireguard_get_device_list_free(devs);
+	wireguard_get_device_req_free(req);
+	ynl_sock_destroy(ys);
+
+	return 0;
+
+err_close:
+	fprintf(stderr, "YNL (%d): %s\n", ys->err.code, ys->err.msg);
+	wireguard_get_device_req_free(req);
+	ynl_sock_destroy(ys);
+	return 3;
+}
-- 
2.51.0

[PATCH wireguard v4 10/10] wireguard: netlink: generate netlink code

[Asbjørn Sloth Tønnesen]

This patch adopts netlink policies and command definitions
generated by ynl-gen, thus completing the conversion to YNL.

Given that the old and new policies are functionally identical
and have just been moved to a new file, it serves to verify
that the policies generated from the spec are identical to the
previous policy code.

The following functions are renamed:
  wg_get_device_dump() -> wg_get_device_dumpit()
  wg_set_device()      -> wg_set_device_doit()

The new files are covered by the existing drivers/net/wireguard/
pattern in MAINTAINERS.

No behavioural changes intended.

Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
---
 drivers/net/wireguard/Makefile            |  2 +-
 drivers/net/wireguard/generated/netlink.c | 73 +++++++++++++++++++++++
 drivers/net/wireguard/generated/netlink.h | 30 ++++++++++
 drivers/net/wireguard/netlink.c           | 60 ++-----------------
 4 files changed, 109 insertions(+), 56 deletions(-)
 create mode 100644 drivers/net/wireguard/generated/netlink.c
 create mode 100644 drivers/net/wireguard/generated/netlink.h

diff --git a/drivers/net/wireguard/Makefile b/drivers/net/wireguard/Makefile
index dbe1f8514efc3..00cbcc9ab69da 100644
--- a/drivers/net/wireguard/Makefile
+++ b/drivers/net/wireguard/Makefile
@@ -13,5 +13,5 @@ wireguard-y += peerlookup.o
 wireguard-y += allowedips.o
 wireguard-y += ratelimiter.o
 wireguard-y += cookie.o
-wireguard-y += netlink.o
+wireguard-y += netlink.o generated/netlink.o
 obj-$(CONFIG_WIREGUARD) := wireguard.o
diff --git a/drivers/net/wireguard/generated/netlink.c b/drivers/net/wireguard/generated/netlink.c
new file mode 100644
index 0000000000000..3ef8c29908c28
--- /dev/null
+++ b/drivers/net/wireguard/generated/netlink.c
@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)
+/* Do not edit directly, auto-generated from: */
+/*	Documentation/netlink/specs/wireguard.yaml */
+/* YNL-GEN kernel source */
+/* YNL-ARG --function-prefix wg */
+/* To regenerate run: tools/net/ynl/ynl-regen.sh */
+
+#include <net/netlink.h>
+#include <net/genetlink.h>
+
+#include "netlink.h"
+
+#include <uapi/linux/wireguard.h>
+#include <linux/time_types.h>
+
+/* Common nested types */
+const struct nla_policy wireguard_wgallowedip_nl_policy[WGALLOWEDIP_A_FLAGS + 1] = {
+	[WGALLOWEDIP_A_FAMILY] = { .type = NLA_U16, },
+	[WGALLOWEDIP_A_IPADDR] = NLA_POLICY_MIN_LEN(4),
+	[WGALLOWEDIP_A_CIDR_MASK] = { .type = NLA_U8, },
+	[WGALLOWEDIP_A_FLAGS] = NLA_POLICY_MASK(NLA_U32, 0x1),
+};
+
+const struct nla_policy wireguard_wgpeer_nl_policy[WGPEER_A_PROTOCOL_VERSION + 1] = {
+	[WGPEER_A_PUBLIC_KEY] = NLA_POLICY_EXACT_LEN(WG_KEY_LEN),
+	[WGPEER_A_PRESHARED_KEY] = NLA_POLICY_EXACT_LEN(WG_KEY_LEN),
+	[WGPEER_A_FLAGS] = NLA_POLICY_MASK(NLA_U32, 0x7),
+	[WGPEER_A_ENDPOINT] = NLA_POLICY_MIN_LEN(16),
+	[WGPEER_A_PERSISTENT_KEEPALIVE_INTERVAL] = { .type = NLA_U16, },
+	[WGPEER_A_LAST_HANDSHAKE_TIME] = NLA_POLICY_EXACT_LEN(16),
+	[WGPEER_A_RX_BYTES] = { .type = NLA_U64, },
+	[WGPEER_A_TX_BYTES] = { .type = NLA_U64, },
+	[WGPEER_A_ALLOWEDIPS] = NLA_POLICY_NESTED_ARRAY(wireguard_wgallowedip_nl_policy),
+	[WGPEER_A_PROTOCOL_VERSION] = { .type = NLA_U32, },
+};
+
+/* WG_CMD_GET_DEVICE - dump */
+static const struct nla_policy wireguard_get_device_nl_policy[WGDEVICE_A_IFNAME + 1] = {
+	[WGDEVICE_A_IFINDEX] = { .type = NLA_U32, },
+	[WGDEVICE_A_IFNAME] = { .type = NLA_NUL_STRING, .len = 15, },
+};
+
+/* WG_CMD_SET_DEVICE - do */
+static const struct nla_policy wireguard_set_device_nl_policy[WGDEVICE_A_PEERS + 1] = {
+	[WGDEVICE_A_IFINDEX] = { .type = NLA_U32, },
+	[WGDEVICE_A_IFNAME] = { .type = NLA_NUL_STRING, .len = 15, },
+	[WGDEVICE_A_PRIVATE_KEY] = NLA_POLICY_EXACT_LEN(WG_KEY_LEN),
+	[WGDEVICE_A_PUBLIC_KEY] = NLA_POLICY_EXACT_LEN(WG_KEY_LEN),
+	[WGDEVICE_A_FLAGS] = NLA_POLICY_MASK(NLA_U32, 0x1),
+	[WGDEVICE_A_LISTEN_PORT] = { .type = NLA_U16, },
+	[WGDEVICE_A_FWMARK] = { .type = NLA_U32, },
+	[WGDEVICE_A_PEERS] = NLA_POLICY_NESTED_ARRAY(wireguard_wgpeer_nl_policy),
+};
+
+/* Ops table for wireguard */
+const struct genl_split_ops wireguard_nl_ops[2] = {
+	{
+		.cmd		= WG_CMD_GET_DEVICE,
+		.start		= wg_get_device_start,
+		.dumpit		= wg_get_device_dumpit,
+		.done		= wg_get_device_done,
+		.policy		= wireguard_get_device_nl_policy,
+		.maxattr	= WGDEVICE_A_IFNAME,
+		.flags		= GENL_UNS_ADMIN_PERM | GENL_CMD_CAP_DUMP,
+	},
+	{
+		.cmd		= WG_CMD_SET_DEVICE,
+		.doit		= wg_set_device_doit,
+		.policy		= wireguard_set_device_nl_policy,
+		.maxattr	= WGDEVICE_A_PEERS,
+		.flags		= GENL_UNS_ADMIN_PERM | GENL_CMD_CAP_DO,
+	},
+};
diff --git a/drivers/net/wireguard/generated/netlink.h b/drivers/net/wireguard/generated/netlink.h
new file mode 100644
index 0000000000000..5dc977ee9e7c9
--- /dev/null
+++ b/drivers/net/wireguard/generated/netlink.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) */
+/* Do not edit directly, auto-generated from: */
+/*	Documentation/netlink/specs/wireguard.yaml */
+/* YNL-GEN kernel header */
+/* YNL-ARG --function-prefix wg */
+/* To regenerate run: tools/net/ynl/ynl-regen.sh */
+
+#ifndef _LINUX_WIREGUARD_GEN_H
+#define _LINUX_WIREGUARD_GEN_H
+
+#include <net/netlink.h>
+#include <net/genetlink.h>
+
+#include <uapi/linux/wireguard.h>
+#include <linux/time_types.h>
+
+/* Common nested types */
+extern const struct nla_policy wireguard_wgallowedip_nl_policy[WGALLOWEDIP_A_FLAGS + 1];
+extern const struct nla_policy wireguard_wgpeer_nl_policy[WGPEER_A_PROTOCOL_VERSION + 1];
+
+/* Ops table for wireguard */
+extern const struct genl_split_ops wireguard_nl_ops[2];
+
+int wg_get_device_start(struct netlink_callback *cb);
+int wg_get_device_done(struct netlink_callback *cb);
+
+int wg_get_device_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
+int wg_set_device_doit(struct sk_buff *skb, struct genl_info *info);
+
+#endif /* _LINUX_WIREGUARD_GEN_H */
diff --git a/drivers/net/wireguard/netlink.c b/drivers/net/wireguard/netlink.c
index 0ce0bda8c1ce8..1da7e98d0d509 100644
--- a/drivers/net/wireguard/netlink.c
+++ b/drivers/net/wireguard/netlink.c
@@ -9,6 +9,7 @@
 #include "socket.h"
 #include "queueing.h"
 #include "messages.h"
+#include "generated/netlink.h"
 
 #include <uapi/linux/wireguard.h>
 
@@ -18,39 +19,6 @@
 #include <crypto/utils.h>
 
 static struct genl_family genl_family;
-static const struct nla_policy peer_policy[WGPEER_A_MAX + 1];
-static const struct nla_policy allowedip_policy[WGALLOWEDIP_A_MAX + 1];
-
-static const struct nla_policy device_policy[WGDEVICE_A_MAX + 1] = {
-	[WGDEVICE_A_IFINDEX]		= { .type = NLA_U32 },
-	[WGDEVICE_A_IFNAME]		= { .type = NLA_NUL_STRING, .len = IFNAMSIZ - 1 },
-	[WGDEVICE_A_PRIVATE_KEY]	= NLA_POLICY_EXACT_LEN(WG_KEY_LEN),
-	[WGDEVICE_A_PUBLIC_KEY]		= NLA_POLICY_EXACT_LEN(WG_KEY_LEN),
-	[WGDEVICE_A_FLAGS]		= NLA_POLICY_MASK(NLA_U32, 0x1),
-	[WGDEVICE_A_LISTEN_PORT]	= { .type = NLA_U16 },
-	[WGDEVICE_A_FWMARK]		= { .type = NLA_U32 },
-	[WGDEVICE_A_PEERS]		= NLA_POLICY_NESTED_ARRAY(peer_policy),
-};
-
-static const struct nla_policy peer_policy[WGPEER_A_MAX + 1] = {
-	[WGPEER_A_PUBLIC_KEY]				= NLA_POLICY_EXACT_LEN(WG_KEY_LEN),
-	[WGPEER_A_PRESHARED_KEY]			= NLA_POLICY_EXACT_LEN(WG_KEY_LEN),
-	[WGPEER_A_FLAGS]				= NLA_POLICY_MASK(NLA_U32, 0x7),
-	[WGPEER_A_ENDPOINT]				= NLA_POLICY_MIN_LEN(sizeof(struct sockaddr)),
-	[WGPEER_A_PERSISTENT_KEEPALIVE_INTERVAL]	= { .type = NLA_U16 },
-	[WGPEER_A_LAST_HANDSHAKE_TIME]			= NLA_POLICY_EXACT_LEN(sizeof(struct __kernel_timespec)),
-	[WGPEER_A_RX_BYTES]				= { .type = NLA_U64 },
-	[WGPEER_A_TX_BYTES]				= { .type = NLA_U64 },
-	[WGPEER_A_ALLOWEDIPS]				= NLA_POLICY_NESTED_ARRAY(allowedip_policy),
-	[WGPEER_A_PROTOCOL_VERSION]			= { .type = NLA_U32 }
-};
-
-static const struct nla_policy allowedip_policy[WGALLOWEDIP_A_MAX + 1] = {
-	[WGALLOWEDIP_A_FAMILY]		= { .type = NLA_U16 },
-	[WGALLOWEDIP_A_IPADDR]		= NLA_POLICY_MIN_LEN(sizeof(struct in_addr)),
-	[WGALLOWEDIP_A_CIDR_MASK]	= { .type = NLA_U8 },
-	[WGALLOWEDIP_A_FLAGS]		= NLA_POLICY_MASK(NLA_U32, 0x1),
-};
 
 static struct wg_device *lookup_interface(struct nlattr **attrs,
 					  struct sk_buff *skb)
@@ -199,7 +167,7 @@ get_peer(struct wg_peer *peer, struct sk_buff *skb, struct dump_ctx *ctx)
 	return -EMSGSIZE;
 }
 
-static int wg_get_device_start(struct netlink_callback *cb)
+int wg_get_device_start(struct netlink_callback *cb)
 {
 	struct wg_device *wg;
 
@@ -210,7 +178,7 @@ static int wg_get_device_start(struct netlink_callback *cb)
 	return 0;
 }
 
-static int wg_get_device_dump(struct sk_buff *skb, struct netlink_callback *cb)
+int wg_get_device_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
 {
 	struct wg_peer *peer, *next_peer_cursor;
 	struct dump_ctx *ctx = DUMP_CTX(cb);
@@ -304,7 +272,7 @@ static int wg_get_device_dump(struct sk_buff *skb, struct netlink_callback *cb)
 	 */
 }
 
-static int wg_get_device_done(struct netlink_callback *cb)
+int wg_get_device_done(struct netlink_callback *cb)
 {
 	struct dump_ctx *ctx = DUMP_CTX(cb);
 
@@ -502,7 +470,7 @@ static int set_peer(struct wg_device *wg, struct nlattr **attrs)
 	return ret;
 }
 
-static int wg_set_device(struct sk_buff *skb, struct genl_info *info)
+int wg_set_device_doit(struct sk_buff *skb, struct genl_info *info)
 {
 	struct wg_device *wg = lookup_interface(info->attrs, skb);
 	u32 flags = 0;
@@ -616,24 +584,6 @@ static int wg_set_device(struct sk_buff *skb, struct genl_info *info)
 	return ret;
 }
 
-static const struct genl_split_ops wireguard_nl_ops[] = {
-	{
-		.cmd = WG_CMD_GET_DEVICE,
-		.start = wg_get_device_start,
-		.dumpit = wg_get_device_dump,
-		.done = wg_get_device_done,
-		.policy = device_policy,
-		.maxattr = WGDEVICE_A_IFNAME,
-		.flags = GENL_UNS_ADMIN_PERM | GENL_CMD_CAP_DUMP,
-	}, {
-		.cmd = WG_CMD_SET_DEVICE,
-		.doit = wg_set_device,
-		.policy = device_policy,
-		.maxattr = WGDEVICE_A_PEERS,
-		.flags = GENL_UNS_ADMIN_PERM | GENL_CMD_CAP_DO,
-	}
-};
-
 static struct genl_family genl_family __ro_after_init = {
 	.split_ops = wireguard_nl_ops,
 	.n_split_ops = ARRAY_SIZE(wireguard_nl_ops),
-- 
2.51.0

Re: [PATCH wireguard v4 00/10] wireguard: netlink: ynl conversion

[Jason A. Donenfeld]

Hi Asbjorn,

Thank you for this! I've merged this to the wireguard devel tree, and
I'll send this up to net-next after letting it cook there for a little
while.

I really appreciate all the work you've put into this and the large
amounts of feedback you've incorporated.

Jason