[patch net-next v3 0/9] devlink: introduce notifications filtering

[patch net-next v3 0/9] devlink: introduce notifications filtering

[Jiri Pirko]

From: Jiri Pirko <jiri@nvidia.com>

Currently the user listening on a socket for devlink notifications
gets always all messages for all existing devlink instances and objects,
even if he is interested only in one of those. That may cause
unnecessary overhead on setups with thousands of instances present.

User is currently able to narrow down the devlink objects replies
to dump commands by specifying select attributes.

Allow similar approach for notifications providing user a new
notify-filter-set command to select attributes with values
the notification message has to match. In that case, it is delivered
to the socket.

Note that the filtering is done per-socket, so multiple users may
specify different selection of attributes with values.

This patchset initially introduces support for following attributes:
DEVLINK_ATTR_BUS_NAME
DEVLINK_ATTR_DEV_NAME
DEVLINK_ATTR_PORT_INDEX

Patches #1 - #4 are preparations in devlink code, patch #3 is
                an optimization done on the way.
Patches #5 - #7 are preparations in netlink and generic netlink code.
Patch #8 is the main one in this set implementing of
         the notify-filter-set command and the actual
         per-socket filtering.
Patch #0 extends the infrastructure allowing to filter according
         to a port index.

Example:
$ devlink mon port pci/0000:08:00.0/32768
[port,new] pci/0000:08:00.0/32768: type notset flavour pcisf controller 0 pfnum 0 sfnum 107 splittable false
  function:
    hw_addr 00:00:00:00:00:00 state inactive opstate detached roce enable
[port,new] pci/0000:08:00.0/32768: type eth flavour pcisf controller 0 pfnum 0 sfnum 107 splittable false
  function:
    hw_addr 00:00:00:00:00:00 state inactive opstate detached roce enable
[port,new] pci/0000:08:00.0/32768: type eth netdev eth3 flavour pcisf controller 0 pfnum 0 sfnum 107 splittable false
  function:
    hw_addr 00:00:00:00:00:00 state inactive opstate detached roce enable
[port,new] pci/0000:08:00.0/32768: type eth netdev eth3 flavour pcisf controller 0 pfnum 0 sfnum 107 splittable false
  function:
    hw_addr 00:00:00:00:00:00 state inactive opstate detached roce enable
[port,new] pci/0000:08:00.0/32768: type eth flavour pcisf controller 0 pfnum 0 sfnum 107 splittable false
  function:
    hw_addr 00:00:00:00:00:00 state inactive opstate detached roce enable
[port,new] pci/0000:08:00.0/32768: type notset flavour pcisf controller 0 pfnum 0 sfnum 107 splittable false
  function:
    hw_addr 00:00:00:00:00:00 state inactive opstate detached roce enable
[port,del] pci/0000:08:00.0/32768: type notset flavour pcisf controller 0 pfnum 0 sfnum 107 splittable false
  function:
    hw_addr 00:00:00:00:00:00 state inactive opstate detached roce enable

---
v2->v3:
- small cosmetical fixes in patch #6
v1->v2:
- added patch #6, fixed generated docs
- see individual patches for details

Jiri Pirko (9):
  devlink: use devl_is_registered() helper instead xa_get_mark()
  devlink: introduce __devl_is_registered() helper and use it instead of
    xa_get_mark()
  devlink: send notifications only if there are listeners
  devlink: introduce a helper for netlink multicast send
  genetlink: implement release callback and free sk_user_data there
  netlink: introduce typedef for filter function
  genetlink: introduce helpers to do filtered multicast
  devlink: add a command to set notification filter and use it for
    multicasts
  devlink: extend multicast filtering by port index

 Documentation/netlink/specs/devlink.yaml | 11 ++++
 drivers/connector/connector.c            |  5 +-
 include/linux/connector.h                |  3 +-
 include/linux/netlink.h                  |  6 +-
 include/net/genetlink.h                  | 35 +++++++++--
 include/net/netlink.h                    | 31 ++++++++--
 include/uapi/linux/devlink.h             |  2 +
 net/devlink/dev.c                        | 13 ++--
 net/devlink/devl_internal.h              | 58 +++++++++++++++++-
 net/devlink/health.c                     | 10 ++-
 net/devlink/linecard.c                   |  5 +-
 net/devlink/netlink.c                    | 77 ++++++++++++++++++++++++
 net/devlink/netlink_gen.c                | 16 ++++-
 net/devlink/netlink_gen.h                |  4 +-
 net/devlink/param.c                      |  5 +-
 net/devlink/port.c                       |  8 ++-
 net/devlink/rate.c                       |  5 +-
 net/devlink/region.c                     |  6 +-
 net/devlink/trap.c                       | 18 +++---
 net/netlink/af_netlink.c                 |  3 +-
 net/netlink/genetlink.c                  |  6 ++
 tools/net/ynl/generated/devlink-user.c   | 33 ++++++++++
 tools/net/ynl/generated/devlink-user.h   | 56 +++++++++++++++++
 23 files changed, 364 insertions(+), 52 deletions(-)

-- 
2.41.0

[patch net-next v3 1/9] devlink: use devl_is_registered() helper instead xa_get_mark()

[Jiri Pirko]

From: Jiri Pirko <jiri@nvidia.com>

Instead of checking the xarray mark directly using xa_get_mark() helper
use devl_is_registered() helper which wraps it up. Note that there are
couple more users of xa_get_mark() left which are going to be handled
by the next patch.

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
---
 net/devlink/dev.c  | 4 ++--
 net/devlink/rate.c | 2 +-
 net/devlink/trap.c | 9 ++++++---
 3 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/net/devlink/dev.c b/net/devlink/dev.c
index 4fc7adb32663..4667ab3e9ff1 100644
--- a/net/devlink/dev.c
+++ b/net/devlink/dev.c
@@ -201,7 +201,7 @@ static void devlink_notify(struct devlink *devlink, enum devlink_command cmd)
 	int err;
 
 	WARN_ON(cmd != DEVLINK_CMD_NEW && cmd != DEVLINK_CMD_DEL);
-	WARN_ON(!xa_get_mark(&devlinks, devlink->index, DEVLINK_REGISTERED));
+	WARN_ON(!devl_is_registered(devlink));
 
 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 	if (!msg)
@@ -977,7 +977,7 @@ static void __devlink_flash_update_notify(struct devlink *devlink,
 		cmd != DEVLINK_CMD_FLASH_UPDATE_END &&
 		cmd != DEVLINK_CMD_FLASH_UPDATE_STATUS);
 
-	if (!xa_get_mark(&devlinks, devlink->index, DEVLINK_REGISTERED))
+	if (!devl_is_registered(devlink))
 		return;
 
 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
diff --git a/net/devlink/rate.c b/net/devlink/rate.c
index 94b289b93ff2..e2190cf22beb 100644
--- a/net/devlink/rate.c
+++ b/net/devlink/rate.c
@@ -146,7 +146,7 @@ static void devlink_rate_notify(struct devlink_rate *devlink_rate,
 
 	WARN_ON(cmd != DEVLINK_CMD_RATE_NEW && cmd != DEVLINK_CMD_RATE_DEL);
 
-	if (!xa_get_mark(&devlinks, devlink->index, DEVLINK_REGISTERED))
+	if (!devl_is_registered(devlink))
 		return;
 
 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
diff --git a/net/devlink/trap.c b/net/devlink/trap.c
index c26313e7ca08..908085e2c990 100644
--- a/net/devlink/trap.c
+++ b/net/devlink/trap.c
@@ -1173,7 +1173,8 @@ devlink_trap_group_notify(struct devlink *devlink,
 
 	WARN_ON_ONCE(cmd != DEVLINK_CMD_TRAP_GROUP_NEW &&
 		     cmd != DEVLINK_CMD_TRAP_GROUP_DEL);
-	if (!xa_get_mark(&devlinks, devlink->index, DEVLINK_REGISTERED))
+
+	if (!devl_is_registered(devlink))
 		return;
 
 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
@@ -1234,7 +1235,8 @@ static void devlink_trap_notify(struct devlink *devlink,
 
 	WARN_ON_ONCE(cmd != DEVLINK_CMD_TRAP_NEW &&
 		     cmd != DEVLINK_CMD_TRAP_DEL);
-	if (!xa_get_mark(&devlinks, devlink->index, DEVLINK_REGISTERED))
+
+	if (!devl_is_registered(devlink))
 		return;
 
 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
@@ -1710,7 +1712,8 @@ devlink_trap_policer_notify(struct devlink *devlink,
 
 	WARN_ON_ONCE(cmd != DEVLINK_CMD_TRAP_POLICER_NEW &&
 		     cmd != DEVLINK_CMD_TRAP_POLICER_DEL);
-	if (!xa_get_mark(&devlinks, devlink->index, DEVLINK_REGISTERED))
+
+	if (!devl_is_registered(devlink))
 		return;
 
 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
-- 
2.41.0

[patch net-next v3 2/9] devlink: introduce __devl_is_registered() helper and use it instead of xa_get_mark()

[Jiri Pirko]

From: Jiri Pirko <jiri@nvidia.com>

Introduce __devl_is_registered() which does not assert on devlink
instance lock and use it in notifications which may be called
without devlink instance lock held.

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
---
 net/devlink/devl_internal.h | 7 ++++++-
 net/devlink/linecard.c      | 2 +-
 net/devlink/port.c          | 2 +-
 net/devlink/region.c        | 3 ++-
 4 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/net/devlink/devl_internal.h b/net/devlink/devl_internal.h
index 183dbe3807ab..381b8e62d906 100644
--- a/net/devlink/devl_internal.h
+++ b/net/devlink/devl_internal.h
@@ -90,10 +90,15 @@ extern struct genl_family devlink_nl_family;
 
 struct devlink *devlinks_xa_find_get(struct net *net, unsigned long *indexp);
 
+static inline bool __devl_is_registered(struct devlink *devlink)
+{
+	return xa_get_mark(&devlinks, devlink->index, DEVLINK_REGISTERED);
+}
+
 static inline bool devl_is_registered(struct devlink *devlink)
 {
 	devl_assert_locked(devlink);
-	return xa_get_mark(&devlinks, devlink->index, DEVLINK_REGISTERED);
+	return __devl_is_registered(devlink);
 }
 
 typedef void devlink_rel_notify_cb_t(struct devlink *devlink, u32 obj_index);
diff --git a/net/devlink/linecard.c b/net/devlink/linecard.c
index 2f1c317b64cd..9d080ac1734b 100644
--- a/net/devlink/linecard.c
+++ b/net/devlink/linecard.c
@@ -136,7 +136,7 @@ static void devlink_linecard_notify(struct devlink_linecard *linecard,
 	WARN_ON(cmd != DEVLINK_CMD_LINECARD_NEW &&
 		cmd != DEVLINK_CMD_LINECARD_DEL);
 
-	if (!xa_get_mark(&devlinks, devlink->index, DEVLINK_REGISTERED))
+	if (!__devl_is_registered(devlink))
 		return;
 
 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
diff --git a/net/devlink/port.c b/net/devlink/port.c
index 7634f187fa50..f229a8699214 100644
--- a/net/devlink/port.c
+++ b/net/devlink/port.c
@@ -512,7 +512,7 @@ static void devlink_port_notify(struct devlink_port *devlink_port,
 
 	WARN_ON(cmd != DEVLINK_CMD_PORT_NEW && cmd != DEVLINK_CMD_PORT_DEL);
 
-	if (!xa_get_mark(&devlinks, devlink->index, DEVLINK_REGISTERED))
+	if (!__devl_is_registered(devlink))
 		return;
 
 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
diff --git a/net/devlink/region.c b/net/devlink/region.c
index 0aab7b82d678..396930324da4 100644
--- a/net/devlink/region.c
+++ b/net/devlink/region.c
@@ -234,7 +234,8 @@ static void devlink_nl_region_notify(struct devlink_region *region,
 	struct sk_buff *msg;
 
 	WARN_ON(cmd != DEVLINK_CMD_REGION_NEW && cmd != DEVLINK_CMD_REGION_DEL);
-	if (!xa_get_mark(&devlinks, devlink->index, DEVLINK_REGISTERED))
+
+	if (!__devl_is_registered(devlink))
 		return;
 
 	msg = devlink_nl_region_notify_build(region, snapshot, cmd, 0, 0);
-- 
2.41.0

[patch net-next v3 3/9] devlink: send notifications only if there are listeners

[Jiri Pirko]

From: Jiri Pirko <jiri@nvidia.com>

Introduce devlink_nl_notify_need() helper and using it to check at the
beginning of notification functions to avoid overhead of composing
notification messages in case nobody listens.

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
---
 net/devlink/dev.c           | 5 ++++-
 net/devlink/devl_internal.h | 6 ++++++
 net/devlink/health.c        | 3 +++
 net/devlink/linecard.c      | 2 +-
 net/devlink/param.c         | 2 +-
 net/devlink/port.c          | 2 +-
 net/devlink/rate.c          | 2 +-
 net/devlink/region.c        | 2 +-
 net/devlink/trap.c          | 6 +++---
 9 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/net/devlink/dev.c b/net/devlink/dev.c
index 4667ab3e9ff1..582b5177f403 100644
--- a/net/devlink/dev.c
+++ b/net/devlink/dev.c
@@ -203,6 +203,9 @@ static void devlink_notify(struct devlink *devlink, enum devlink_command cmd)
 	WARN_ON(cmd != DEVLINK_CMD_NEW && cmd != DEVLINK_CMD_DEL);
 	WARN_ON(!devl_is_registered(devlink));
 
+	if (!devlink_nl_notify_need(devlink))
+		return;
+
 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 	if (!msg)
 		return;
@@ -977,7 +980,7 @@ static void __devlink_flash_update_notify(struct devlink *devlink,
 		cmd != DEVLINK_CMD_FLASH_UPDATE_END &&
 		cmd != DEVLINK_CMD_FLASH_UPDATE_STATUS);
 
-	if (!devl_is_registered(devlink))
+	if (!devl_is_registered(devlink) || !devlink_nl_notify_need(devlink))
 		return;
 
 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
diff --git a/net/devlink/devl_internal.h b/net/devlink/devl_internal.h
index 381b8e62d906..8b48a07eb7b7 100644
--- a/net/devlink/devl_internal.h
+++ b/net/devlink/devl_internal.h
@@ -172,6 +172,12 @@ int devlink_nl_put_nested_handle(struct sk_buff *msg, struct net *net,
 				 struct devlink *devlink, int attrtype);
 int devlink_nl_msg_reply_and_new(struct sk_buff **msg, struct genl_info *info);
 
+static inline bool devlink_nl_notify_need(struct devlink *devlink)
+{
+	return genl_has_listeners(&devlink_nl_family, devlink_net(devlink),
+				  DEVLINK_MCGRP_CONFIG);
+}
+
 /* Notify */
 void devlink_notify_register(struct devlink *devlink);
 void devlink_notify_unregister(struct devlink *devlink);
diff --git a/net/devlink/health.c b/net/devlink/health.c
index 695df61f8ac2..93eae8b5d2d3 100644
--- a/net/devlink/health.c
+++ b/net/devlink/health.c
@@ -496,6 +496,9 @@ static void devlink_recover_notify(struct devlink_health_reporter *reporter,
 	WARN_ON(cmd != DEVLINK_CMD_HEALTH_REPORTER_RECOVER);
 	ASSERT_DEVLINK_REGISTERED(devlink);
 
+	if (!devlink_nl_notify_need(devlink))
+		return;
+
 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
 	if (!msg)
 		return;
diff --git a/net/devlink/linecard.c b/net/devlink/linecard.c
index 9d080ac1734b..45b36975ee6f 100644
--- a/net/devlink/linecard.c
+++ b/net/devlink/linecard.c
@@ -136,7 +136,7 @@ static void devlink_linecard_notify(struct devlink_linecard *linecard,
 	WARN_ON(cmd != DEVLINK_CMD_LINECARD_NEW &&
 		cmd != DEVLINK_CMD_LINECARD_DEL);
 
-	if (!__devl_is_registered(devlink))
+	if (!__devl_is_registered(devlink) || !devlink_nl_notify_need(devlink))
 		return;
 
 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
diff --git a/net/devlink/param.c b/net/devlink/param.c
index d74df09311a9..6bb6aee5d937 100644
--- a/net/devlink/param.c
+++ b/net/devlink/param.c
@@ -343,7 +343,7 @@ static void devlink_param_notify(struct devlink *devlink,
 	 * will replay the notifications if the params are added/removed
 	 * outside of the lifetime of the instance.
 	 */
-	if (!devl_is_registered(devlink))
+	if (!devlink_nl_notify_need(devlink) || !devl_is_registered(devlink))
 		return;
 
 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
diff --git a/net/devlink/port.c b/net/devlink/port.c
index f229a8699214..32f4d0331e63 100644
--- a/net/devlink/port.c
+++ b/net/devlink/port.c
@@ -512,7 +512,7 @@ static void devlink_port_notify(struct devlink_port *devlink_port,
 
 	WARN_ON(cmd != DEVLINK_CMD_PORT_NEW && cmd != DEVLINK_CMD_PORT_DEL);
 
-	if (!__devl_is_registered(devlink))
+	if (!__devl_is_registered(devlink) || !devlink_nl_notify_need(devlink))
 		return;
 
 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
diff --git a/net/devlink/rate.c b/net/devlink/rate.c
index e2190cf22beb..0371a2dd3e0a 100644
--- a/net/devlink/rate.c
+++ b/net/devlink/rate.c
@@ -146,7 +146,7 @@ static void devlink_rate_notify(struct devlink_rate *devlink_rate,
 
 	WARN_ON(cmd != DEVLINK_CMD_RATE_NEW && cmd != DEVLINK_CMD_RATE_DEL);
 
-	if (!devl_is_registered(devlink))
+	if (!devl_is_registered(devlink) || !devlink_nl_notify_need(devlink))
 		return;
 
 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
diff --git a/net/devlink/region.c b/net/devlink/region.c
index 396930324da4..f1402da66277 100644
--- a/net/devlink/region.c
+++ b/net/devlink/region.c
@@ -235,7 +235,7 @@ static void devlink_nl_region_notify(struct devlink_region *region,
 
 	WARN_ON(cmd != DEVLINK_CMD_REGION_NEW && cmd != DEVLINK_CMD_REGION_DEL);
 
-	if (!__devl_is_registered(devlink))
+	if (!__devl_is_registered(devlink) || !devlink_nl_notify_need(devlink))
 		return;
 
 	msg = devlink_nl_region_notify_build(region, snapshot, cmd, 0, 0);
diff --git a/net/devlink/trap.c b/net/devlink/trap.c
index 908085e2c990..3ca1ca7e2e64 100644
--- a/net/devlink/trap.c
+++ b/net/devlink/trap.c
@@ -1174,7 +1174,7 @@ devlink_trap_group_notify(struct devlink *devlink,
 	WARN_ON_ONCE(cmd != DEVLINK_CMD_TRAP_GROUP_NEW &&
 		     cmd != DEVLINK_CMD_TRAP_GROUP_DEL);
 
-	if (!devl_is_registered(devlink))
+	if (!devl_is_registered(devlink) || !devlink_nl_notify_need(devlink))
 		return;
 
 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
@@ -1236,7 +1236,7 @@ static void devlink_trap_notify(struct devlink *devlink,
 	WARN_ON_ONCE(cmd != DEVLINK_CMD_TRAP_NEW &&
 		     cmd != DEVLINK_CMD_TRAP_DEL);
 
-	if (!devl_is_registered(devlink))
+	if (!devl_is_registered(devlink) || !devlink_nl_notify_need(devlink))
 		return;
 
 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
@@ -1713,7 +1713,7 @@ devlink_trap_policer_notify(struct devlink *devlink,
 	WARN_ON_ONCE(cmd != DEVLINK_CMD_TRAP_POLICER_NEW &&
 		     cmd != DEVLINK_CMD_TRAP_POLICER_DEL);
 
-	if (!devl_is_registered(devlink))
+	if (!devl_is_registered(devlink) || !devlink_nl_notify_need(devlink))
 		return;
 
 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
-- 
2.41.0

[patch net-next v3 4/9] devlink: introduce a helper for netlink multicast send

[Jiri Pirko]

From: Jiri Pirko <jiri@nvidia.com>

Introduce a helper devlink_nl_notify_send() so each object notification
function does not have to call genlmsg_multicast_netns() with the same
arguments.

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
---
 net/devlink/dev.c           | 6 ++----
 net/devlink/devl_internal.h | 7 +++++++
 net/devlink/health.c        | 3 +--
 net/devlink/linecard.c      | 3 +--
 net/devlink/param.c         | 3 +--
 net/devlink/port.c          | 3 +--
 net/devlink/rate.c          | 3 +--
 net/devlink/region.c        | 3 +--
 net/devlink/trap.c          | 9 +++------
 9 files changed, 18 insertions(+), 22 deletions(-)

diff --git a/net/devlink/dev.c b/net/devlink/dev.c
index 582b5177f403..ecbc6d51b624 100644
--- a/net/devlink/dev.c
+++ b/net/devlink/dev.c
@@ -216,8 +216,7 @@ static void devlink_notify(struct devlink *devlink, enum devlink_command cmd)
 		return;
 	}
 
-	genlmsg_multicast_netns(&devlink_nl_family, devlink_net(devlink),
-				msg, 0, DEVLINK_MCGRP_CONFIG, GFP_KERNEL);
+	devlink_nl_notify_send(devlink, msg);
 }
 
 int devlink_nl_get_doit(struct sk_buff *skb, struct genl_info *info)
@@ -991,8 +990,7 @@ static void __devlink_flash_update_notify(struct devlink *devlink,
 	if (err)
 		goto out_free_msg;
 
-	genlmsg_multicast_netns(&devlink_nl_family, devlink_net(devlink),
-				msg, 0, DEVLINK_MCGRP_CONFIG, GFP_KERNEL);
+	devlink_nl_notify_send(devlink, msg);
 	return;
 
 out_free_msg:
diff --git a/net/devlink/devl_internal.h b/net/devlink/devl_internal.h
index 8b48a07eb7b7..e19e8dd47092 100644
--- a/net/devlink/devl_internal.h
+++ b/net/devlink/devl_internal.h
@@ -178,6 +178,13 @@ static inline bool devlink_nl_notify_need(struct devlink *devlink)
 				  DEVLINK_MCGRP_CONFIG);
 }
 
+static inline void devlink_nl_notify_send(struct devlink *devlink,
+					  struct sk_buff *msg)
+{
+	genlmsg_multicast_netns(&devlink_nl_family, devlink_net(devlink),
+				msg, 0, DEVLINK_MCGRP_CONFIG, GFP_KERNEL);
+}
+
 /* Notify */
 void devlink_notify_register(struct devlink *devlink);
 void devlink_notify_unregister(struct devlink *devlink);
diff --git a/net/devlink/health.c b/net/devlink/health.c
index 93eae8b5d2d3..2f06e4ddbf3b 100644
--- a/net/devlink/health.c
+++ b/net/devlink/health.c
@@ -509,8 +509,7 @@ static void devlink_recover_notify(struct devlink_health_reporter *reporter,
 		return;
 	}
 
-	genlmsg_multicast_netns(&devlink_nl_family, devlink_net(devlink), msg,
-				0, DEVLINK_MCGRP_CONFIG, GFP_KERNEL);
+	devlink_nl_notify_send(devlink, msg);
 }
 
 void
diff --git a/net/devlink/linecard.c b/net/devlink/linecard.c
index 45b36975ee6f..67f70a621d27 100644
--- a/net/devlink/linecard.c
+++ b/net/devlink/linecard.c
@@ -150,8 +150,7 @@ static void devlink_linecard_notify(struct devlink_linecard *linecard,
 		return;
 	}
 
-	genlmsg_multicast_netns(&devlink_nl_family, devlink_net(devlink),
-				msg, 0, DEVLINK_MCGRP_CONFIG, GFP_KERNEL);
+	devlink_nl_notify_send(devlink, msg);
 }
 
 void devlink_linecards_notify_register(struct devlink *devlink)
diff --git a/net/devlink/param.c b/net/devlink/param.c
index 6bb6aee5d937..854a3af65db9 100644
--- a/net/devlink/param.c
+++ b/net/devlink/param.c
@@ -356,8 +356,7 @@ static void devlink_param_notify(struct devlink *devlink,
 		return;
 	}
 
-	genlmsg_multicast_netns(&devlink_nl_family, devlink_net(devlink),
-				msg, 0, DEVLINK_MCGRP_CONFIG, GFP_KERNEL);
+	devlink_nl_notify_send(devlink, msg);
 }
 
 static void devlink_params_notify(struct devlink *devlink,
diff --git a/net/devlink/port.c b/net/devlink/port.c
index 32f4d0331e63..758df3000a1b 100644
--- a/net/devlink/port.c
+++ b/net/devlink/port.c
@@ -525,8 +525,7 @@ static void devlink_port_notify(struct devlink_port *devlink_port,
 		return;
 	}
 
-	genlmsg_multicast_netns(&devlink_nl_family, devlink_net(devlink), msg,
-				0, DEVLINK_MCGRP_CONFIG, GFP_KERNEL);
+	devlink_nl_notify_send(devlink, msg);
 }
 
 static void devlink_ports_notify(struct devlink *devlink,
diff --git a/net/devlink/rate.c b/net/devlink/rate.c
index 0371a2dd3e0a..7139e67e93ae 100644
--- a/net/devlink/rate.c
+++ b/net/devlink/rate.c
@@ -159,8 +159,7 @@ static void devlink_rate_notify(struct devlink_rate *devlink_rate,
 		return;
 	}
 
-	genlmsg_multicast_netns(&devlink_nl_family, devlink_net(devlink), msg,
-				0, DEVLINK_MCGRP_CONFIG, GFP_KERNEL);
+	devlink_nl_notify_send(devlink, msg);
 }
 
 void devlink_rates_notify_register(struct devlink *devlink)
diff --git a/net/devlink/region.c b/net/devlink/region.c
index f1402da66277..fd6bfabc0c33 100644
--- a/net/devlink/region.c
+++ b/net/devlink/region.c
@@ -242,8 +242,7 @@ static void devlink_nl_region_notify(struct devlink_region *region,
 	if (IS_ERR(msg))
 		return;
 
-	genlmsg_multicast_netns(&devlink_nl_family, devlink_net(devlink), msg,
-				0, DEVLINK_MCGRP_CONFIG, GFP_KERNEL);
+	devlink_nl_notify_send(devlink, msg);
 }
 
 void devlink_regions_notify_register(struct devlink *devlink)
diff --git a/net/devlink/trap.c b/net/devlink/trap.c
index 3ca1ca7e2e64..5d18c7424df1 100644
--- a/net/devlink/trap.c
+++ b/net/devlink/trap.c
@@ -1188,8 +1188,7 @@ devlink_trap_group_notify(struct devlink *devlink,
 		return;
 	}
 
-	genlmsg_multicast_netns(&devlink_nl_family, devlink_net(devlink),
-				msg, 0, DEVLINK_MCGRP_CONFIG, GFP_KERNEL);
+	devlink_nl_notify_send(devlink, msg);
 }
 
 void devlink_trap_groups_notify_register(struct devlink *devlink)
@@ -1249,8 +1248,7 @@ static void devlink_trap_notify(struct devlink *devlink,
 		return;
 	}
 
-	genlmsg_multicast_netns(&devlink_nl_family, devlink_net(devlink),
-				msg, 0, DEVLINK_MCGRP_CONFIG, GFP_KERNEL);
+	devlink_nl_notify_send(devlink, msg);
 }
 
 void devlink_traps_notify_register(struct devlink *devlink)
@@ -1727,8 +1725,7 @@ devlink_trap_policer_notify(struct devlink *devlink,
 		return;
 	}
 
-	genlmsg_multicast_netns(&devlink_nl_family, devlink_net(devlink),
-				msg, 0, DEVLINK_MCGRP_CONFIG, GFP_KERNEL);
+	devlink_nl_notify_send(devlink, msg);
 }
 
 void devlink_trap_policers_notify_register(struct devlink *devlink)
-- 
2.41.0

[patch net-next v3 5/9] genetlink: implement release callback and free sk_user_data there

[Jiri Pirko]

From: Jiri Pirko <jiri@nvidia.com>

If any generic netlink family would like to allocate data store the
pointer to sk_user_data, there is no way to do cleanup in the family
code.

Assume that kfree() is good for now, as the only user introduced by the
follow-up patch (devlink) will use kzalloc() for the allocation of
the memory pointed by a pointer stored in sk_user_data. If later on
this needs to be implemented per-family, a callback is going
to be needed. Until then (if ever), do this in a simple way.

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
---
 net/netlink/genetlink.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c
index 92ef5ed2e7b0..905c5a167f53 100644
--- a/net/netlink/genetlink.c
+++ b/net/netlink/genetlink.c
@@ -1699,12 +1699,18 @@ static int genl_bind(struct net *net, int group)
 	return ret;
 }
 
+static void genl_release(struct sock *sk, unsigned long *groups)
+{
+	kfree(sk->sk_user_data);
+}
+
 static int __net_init genl_pernet_init(struct net *net)
 {
 	struct netlink_kernel_cfg cfg = {
 		.input		= genl_rcv,
 		.flags		= NL_CFG_F_NONROOT_RECV,
 		.bind		= genl_bind,
+		.release	= genl_release,
 	};
 
 	/* we'll bump the group number right afterwards */
-- 
2.41.0

[patch net-next v3 6/9] netlink: introduce typedef for filter function

[Jiri Pirko]

From: Jiri Pirko <jiri@nvidia.com>

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

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
---
v2->v3:
- left the original .c and .h arg names and types
  inconsistencies for cn_netlink_send_mult() and
  netlink_broadcast_filtered()
v1->v2:
- new patch
---
 drivers/connector/connector.c | 5 ++---
 include/linux/connector.h     | 3 +--
 include/linux/netlink.h       | 6 ++++--
 net/netlink/af_netlink.c      | 3 +--
 4 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/drivers/connector/connector.c b/drivers/connector/connector.c
index 7f7b94f616a6..4028e8eeba82 100644
--- a/drivers/connector/connector.c
+++ b/drivers/connector/connector.c
@@ -59,9 +59,8 @@ static int cn_already_initialized;
  * both, or if both are zero then the group is looked up and sent there.
  */
 int cn_netlink_send_mult(struct cn_msg *msg, u16 len, u32 portid, u32 __group,
-	gfp_t gfp_mask,
-	int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data),
-	void *filter_data)
+			 gfp_t gfp_mask, netlink_filter_fn filter,
+			 void *filter_data)
 {
 	struct cn_callback_entry *__cbq;
 	unsigned int size;
diff --git a/include/linux/connector.h b/include/linux/connector.h
index cec2d99ae902..70bc1160f3d8 100644
--- a/include/linux/connector.h
+++ b/include/linux/connector.h
@@ -100,8 +100,7 @@ void cn_del_callback(const struct cb_id *id);
  */
 int cn_netlink_send_mult(struct cn_msg *msg, u16 len, u32 portid,
 			 u32 group, gfp_t gfp_mask,
-			 int (*filter)(struct sock *dsk, struct sk_buff *skb,
-				       void *data),
+			 netlink_filter_fn filter,
 			 void *filter_data);
 
 /**
diff --git a/include/linux/netlink.h b/include/linux/netlink.h
index 75d7de34c908..d30f599a4c6b 100644
--- a/include/linux/netlink.h
+++ b/include/linux/netlink.h
@@ -228,10 +228,12 @@ bool netlink_strict_get_check(struct sk_buff *skb);
 int netlink_unicast(struct sock *ssk, struct sk_buff *skb, __u32 portid, int nonblock);
 int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, __u32 portid,
 		      __u32 group, gfp_t allocation);
+
+typedef int (*netlink_filter_fn)(struct sock *dsk, struct sk_buff *skb, void *data);
+
 int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb,
 			       __u32 portid, __u32 group, gfp_t allocation,
-			       int (*filter)(struct sock *dsk,
-					     struct sk_buff *skb, void *data),
+			       netlink_filter_fn filter,
 			       void *filter_data);
 int netlink_set_err(struct sock *ssk, __u32 portid, __u32 group, int code);
 int netlink_register_notifier(struct notifier_block *nb);
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index eb086b06d60d..c81dc7c60e02 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -1520,8 +1520,7 @@ static void do_one_broadcast(struct sock *sk,
 int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb,
 			       u32 portid,
 			       u32 group, gfp_t allocation,
-			       int (*filter)(struct sock *dsk,
-					     struct sk_buff *skb, void *data),
+			       netlink_filter_fn filter,
 			       void *filter_data)
 {
 	struct net *net = sock_net(ssk);
-- 
2.41.0

[patch net-next v3 7/9] genetlink: introduce helpers to do filtered multicast

[Jiri Pirko]

From: Jiri Pirko <jiri@nvidia.com>

Currently it is possible for netlink kernel user to pass custom
filter function to broadcast send function netlink_broadcast_filtered().
However, this is not exposed to multicast send and to generic
netlink users.

Extend the api and introduce a netlink helper nlmsg_multicast_filtered()
and a generic netlink helper genlmsg_multicast_netns_filtered()
to allow generic netlink families to specify filter function
while sending multicast messages.

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
---
v1->v2:
- used netlink_filter_fn introduce by the previous patch
- added return comments to silence scripts/kernel-doc warnings
---
 include/net/genetlink.h | 35 +++++++++++++++++++++++++++++++----
 include/net/netlink.h   | 31 +++++++++++++++++++++++++++----
 2 files changed, 58 insertions(+), 8 deletions(-)

diff --git a/include/net/genetlink.h b/include/net/genetlink.h
index e18a4c0d69ee..246912033e77 100644
--- a/include/net/genetlink.h
+++ b/include/net/genetlink.h
@@ -435,6 +435,35 @@ static inline void genlmsg_cancel(struct sk_buff *skb, void *hdr)
 		nlmsg_cancel(skb, hdr - GENL_HDRLEN - NLMSG_HDRLEN);
 }
 
+/**
+ * genlmsg_multicast_netns_filtered - multicast a netlink message
+ *				      to a specific netns with filter
+ *				      function
+ * @family: the generic netlink family
+ * @net: the net namespace
+ * @skb: netlink message as socket buffer
+ * @portid: own netlink portid to avoid sending to yourself
+ * @group: offset of multicast group in groups array
+ * @flags: allocation flags
+ * @filter: filter function
+ * @filter_data: filter function private data
+ *
+ * Return: 0 on success, negative error code for failure.
+ */
+static inline int
+genlmsg_multicast_netns_filtered(const struct genl_family *family,
+				 struct net *net, struct sk_buff *skb,
+				 u32 portid, unsigned int group, gfp_t flags,
+				 netlink_filter_fn filter,
+				 void *filter_data)
+{
+	if (WARN_ON_ONCE(group >= family->n_mcgrps))
+		return -EINVAL;
+	group = family->mcgrp_offset + group;
+	return nlmsg_multicast_filtered(net->genl_sock, skb, portid, group,
+					flags, filter, filter_data);
+}
+
 /**
  * genlmsg_multicast_netns - multicast a netlink message to a specific netns
  * @family: the generic netlink family
@@ -448,10 +477,8 @@ static inline int genlmsg_multicast_netns(const struct genl_family *family,
 					  struct net *net, struct sk_buff *skb,
 					  u32 portid, unsigned int group, gfp_t flags)
 {
-	if (WARN_ON_ONCE(group >= family->n_mcgrps))
-		return -EINVAL;
-	group = family->mcgrp_offset + group;
-	return nlmsg_multicast(net->genl_sock, skb, portid, group, flags);
+	return genlmsg_multicast_netns_filtered(family, net, skb, portid,
+						group, flags, NULL, NULL);
 }
 
 /**
diff --git a/include/net/netlink.h b/include/net/netlink.h
index 83bdf787aeee..f5423de36c21 100644
--- a/include/net/netlink.h
+++ b/include/net/netlink.h
@@ -1073,27 +1073,50 @@ static inline void nlmsg_free(struct sk_buff *skb)
 }
 
 /**
- * nlmsg_multicast - multicast a netlink message
+ * nlmsg_multicast_filtered - multicast a netlink message with filter function
  * @sk: netlink socket to spread messages to
  * @skb: netlink message as socket buffer
  * @portid: own netlink portid to avoid sending to yourself
  * @group: multicast group id
  * @flags: allocation flags
+ * @filter: filter function
+ * @filter_data: filter function private data
+ *
+ * Return: 0 on success, negative error code for failure.
  */
-static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb,
-				  u32 portid, unsigned int group, gfp_t flags)
+static inline int nlmsg_multicast_filtered(struct sock *sk, struct sk_buff *skb,
+					   u32 portid, unsigned int group,
+					   gfp_t flags,
+					   netlink_filter_fn filter,
+					   void *filter_data)
 {
 	int err;
 
 	NETLINK_CB(skb).dst_group = group;
 
-	err = netlink_broadcast(sk, skb, portid, group, flags);
+	err = netlink_broadcast_filtered(sk, skb, portid, group, flags,
+					 filter, filter_data);
 	if (err > 0)
 		err = 0;
 
 	return err;
 }
 
+/**
+ * nlmsg_multicast - multicast a netlink message
+ * @sk: netlink socket to spread messages to
+ * @skb: netlink message as socket buffer
+ * @portid: own netlink portid to avoid sending to yourself
+ * @group: multicast group id
+ * @flags: allocation flags
+ */
+static inline int nlmsg_multicast(struct sock *sk, struct sk_buff *skb,
+				  u32 portid, unsigned int group, gfp_t flags)
+{
+	return nlmsg_multicast_filtered(sk, skb, portid, group, flags,
+					NULL, NULL);
+}
+
 /**
  * nlmsg_unicast - unicast a netlink message
  * @sk: netlink socket to spread message to
-- 
2.41.0

[patch net-next v3 8/9] devlink: add a command to set notification filter and use it for multicasts

[Jiri Pirko]

From: Jiri Pirko <jiri@nvidia.com>

Currently the user listening on a socket for devlink notifications
gets always all messages for all existing instances, even if he is
interested only in one of those. That may cause unnecessary overhead
on setups with thousands of instances present.

User is currently able to narrow down the devlink objects replies
to dump commands by specifying select attributes.

Allow similar approach for notifications. Introduce a new devlink
NOTIFY_FILTER_SET which the user passes the select attributes. Store
these per-socket and use them for filtering messages
during multicast send.

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
---
 Documentation/netlink/specs/devlink.yaml | 10 ++++
 include/uapi/linux/devlink.h             |  2 +
 net/devlink/devl_internal.h              | 33 +++++++++++-
 net/devlink/netlink.c                    | 69 ++++++++++++++++++++++++
 net/devlink/netlink_gen.c                | 15 +++++-
 net/devlink/netlink_gen.h                |  4 +-
 tools/net/ynl/generated/devlink-user.c   | 31 +++++++++++
 tools/net/ynl/generated/devlink-user.h   | 47 ++++++++++++++++
 8 files changed, 207 insertions(+), 4 deletions(-)

diff --git a/Documentation/netlink/specs/devlink.yaml b/Documentation/netlink/specs/devlink.yaml
index 572d83a414d0..cc4991cbce83 100644
--- a/Documentation/netlink/specs/devlink.yaml
+++ b/Documentation/netlink/specs/devlink.yaml
@@ -2055,3 +2055,13 @@ operations:
             - bus-name
             - dev-name
             - selftests
+
+    -
+      name: notify-filter-set
+      doc: Set notification messages socket filter.
+      attribute-set: devlink
+      do:
+        request:
+          attributes:
+            - bus-name
+            - dev-name
diff --git a/include/uapi/linux/devlink.h b/include/uapi/linux/devlink.h
index b3c8383d342d..130cae0d3e20 100644
--- a/include/uapi/linux/devlink.h
+++ b/include/uapi/linux/devlink.h
@@ -139,6 +139,8 @@ enum devlink_command {
 	DEVLINK_CMD_SELFTESTS_GET,	/* can dump */
 	DEVLINK_CMD_SELFTESTS_RUN,
 
+	DEVLINK_CMD_NOTIFY_FILTER_SET,
+
 	/* add new commands above here */
 	__DEVLINK_CMD_MAX,
 	DEVLINK_CMD_MAX = __DEVLINK_CMD_MAX - 1
diff --git a/net/devlink/devl_internal.h b/net/devlink/devl_internal.h
index e19e8dd47092..0ee0bcdd4a7d 100644
--- a/net/devlink/devl_internal.h
+++ b/net/devlink/devl_internal.h
@@ -178,11 +178,40 @@ static inline bool devlink_nl_notify_need(struct devlink *devlink)
 				  DEVLINK_MCGRP_CONFIG);
 }
 
+struct devlink_obj_desc {
+	const char *bus_name;
+	const char *dev_name;
+	long data[];
+};
+
+static inline void devlink_nl_obj_desc_init(struct devlink_obj_desc *desc,
+					    struct devlink *devlink)
+{
+	memset(desc, 0, sizeof(*desc));
+	desc->bus_name = devlink->dev->bus->name;
+	desc->dev_name = dev_name(devlink->dev);
+}
+
+int devlink_nl_notify_filter(struct sock *dsk, struct sk_buff *skb, void *data);
+
+static inline void devlink_nl_notify_send_desc(struct devlink *devlink,
+					       struct sk_buff *msg,
+					       struct devlink_obj_desc *desc)
+{
+	genlmsg_multicast_netns_filtered(&devlink_nl_family,
+					 devlink_net(devlink),
+					 msg, 0, DEVLINK_MCGRP_CONFIG,
+					 GFP_KERNEL,
+					 devlink_nl_notify_filter, desc);
+}
+
 static inline void devlink_nl_notify_send(struct devlink *devlink,
 					  struct sk_buff *msg)
 {
-	genlmsg_multicast_netns(&devlink_nl_family, devlink_net(devlink),
-				msg, 0, DEVLINK_MCGRP_CONFIG, GFP_KERNEL);
+	struct devlink_obj_desc desc;
+
+	devlink_nl_obj_desc_init(&desc, devlink);
+	devlink_nl_notify_send_desc(devlink, msg, &desc);
 }
 
 /* Notify */
diff --git a/net/devlink/netlink.c b/net/devlink/netlink.c
index d0b90ebc8b15..738e2f340ab9 100644
--- a/net/devlink/netlink.c
+++ b/net/devlink/netlink.c
@@ -13,6 +13,75 @@ static const struct genl_multicast_group devlink_nl_mcgrps[] = {
 	[DEVLINK_MCGRP_CONFIG] = { .name = DEVLINK_GENL_MCGRP_CONFIG_NAME },
 };
 
+int devlink_nl_notify_filter_set_doit(struct sk_buff *skb,
+				      struct genl_info *info)
+{
+	struct sock *sk = NETLINK_CB(skb).sk;
+	struct nlattr **attrs = info->attrs;
+	struct devlink_obj_desc *flt;
+	size_t data_offset = 0;
+	size_t data_size = 0;
+	char *pos;
+
+	if (attrs[DEVLINK_ATTR_BUS_NAME])
+		data_size += nla_len(attrs[DEVLINK_ATTR_BUS_NAME]) + 1;
+	if (attrs[DEVLINK_ATTR_DEV_NAME])
+		data_size += nla_len(attrs[DEVLINK_ATTR_DEV_NAME]) + 1;
+
+	flt = kzalloc(sizeof(*flt) + data_size, GFP_KERNEL);
+	if (!flt)
+		return -ENOMEM;
+
+	pos = (char *) flt->data;
+	if (attrs[DEVLINK_ATTR_BUS_NAME]) {
+		data_offset += nla_strscpy(pos,
+					   attrs[DEVLINK_ATTR_BUS_NAME],
+					   data_size) + 1;
+		flt->bus_name = pos;
+		pos += data_offset;
+	}
+	if (attrs[DEVLINK_ATTR_DEV_NAME]) {
+		nla_strscpy(pos, attrs[DEVLINK_ATTR_DEV_NAME],
+			    data_size - data_offset);
+		flt->dev_name = pos;
+	}
+
+	/* Free the existing filter if any. */
+	kfree(sk->sk_user_data);
+
+	/* Don't attach empty filter. */
+	if (!flt->bus_name && !flt->dev_name) {
+		kfree(flt);
+		flt = NULL;
+	}
+
+	sk->sk_user_data = flt;
+	return 0;
+}
+
+static bool devlink_obj_desc_match(const struct devlink_obj_desc *desc,
+				   const struct devlink_obj_desc *flt)
+{
+	if (desc->bus_name && flt->bus_name &&
+	    strcmp(desc->bus_name, flt->bus_name))
+		return false;
+	if (desc->dev_name && flt->dev_name &&
+	    strcmp(desc->dev_name, flt->dev_name))
+		return false;
+	return true;
+}
+
+int devlink_nl_notify_filter(struct sock *dsk, struct sk_buff *skb, void *data)
+{
+	struct devlink_obj_desc *flt = dsk->sk_user_data;
+	struct devlink_obj_desc *desc = data;
+
+	if (!flt)
+		return 0;
+
+	return !devlink_obj_desc_match(desc, flt);
+}
+
 int devlink_nl_put_nested_handle(struct sk_buff *msg, struct net *net,
 				 struct devlink *devlink, int attrtype)
 {
diff --git a/net/devlink/netlink_gen.c b/net/devlink/netlink_gen.c
index 788dfdc498a9..f207f3fc7e20 100644
--- a/net/devlink/netlink_gen.c
+++ b/net/devlink/netlink_gen.c
@@ -560,8 +560,14 @@ static const struct nla_policy devlink_selftests_run_nl_policy[DEVLINK_ATTR_SELF
 	[DEVLINK_ATTR_SELFTESTS] = NLA_POLICY_NESTED(devlink_dl_selftest_id_nl_policy),
 };
 
+/* DEVLINK_CMD_NOTIFY_FILTER_SET - do */
+static const struct nla_policy devlink_notify_filter_set_nl_policy[DEVLINK_ATTR_DEV_NAME + 1] = {
+	[DEVLINK_ATTR_BUS_NAME] = { .type = NLA_NUL_STRING, },
+	[DEVLINK_ATTR_DEV_NAME] = { .type = NLA_NUL_STRING, },
+};
+
 /* Ops table for devlink */
-const struct genl_split_ops devlink_nl_ops[73] = {
+const struct genl_split_ops devlink_nl_ops[74] = {
 	{
 		.cmd		= DEVLINK_CMD_GET,
 		.validate	= GENL_DONT_VALIDATE_STRICT,
@@ -1233,4 +1239,11 @@ const struct genl_split_ops devlink_nl_ops[73] = {
 		.maxattr	= DEVLINK_ATTR_SELFTESTS,
 		.flags		= GENL_ADMIN_PERM | GENL_CMD_CAP_DO,
 	},
+	{
+		.cmd		= DEVLINK_CMD_NOTIFY_FILTER_SET,
+		.doit		= devlink_nl_notify_filter_set_doit,
+		.policy		= devlink_notify_filter_set_nl_policy,
+		.maxattr	= DEVLINK_ATTR_DEV_NAME,
+		.flags		= GENL_CMD_CAP_DO,
+	},
 };
diff --git a/net/devlink/netlink_gen.h b/net/devlink/netlink_gen.h
index 0e9e89c31c31..71693d834ad2 100644
--- a/net/devlink/netlink_gen.h
+++ b/net/devlink/netlink_gen.h
@@ -16,7 +16,7 @@ extern const struct nla_policy devlink_dl_port_function_nl_policy[DEVLINK_PORT_F
 extern const struct nla_policy devlink_dl_selftest_id_nl_policy[DEVLINK_ATTR_SELFTEST_ID_FLASH + 1];
 
 /* Ops table for devlink */
-extern const struct genl_split_ops devlink_nl_ops[73];
+extern const struct genl_split_ops devlink_nl_ops[74];
 
 int devlink_nl_pre_doit(const struct genl_split_ops *ops, struct sk_buff *skb,
 			struct genl_info *info);
@@ -137,5 +137,7 @@ int devlink_nl_selftests_get_doit(struct sk_buff *skb, struct genl_info *info);
 int devlink_nl_selftests_get_dumpit(struct sk_buff *skb,
 				    struct netlink_callback *cb);
 int devlink_nl_selftests_run_doit(struct sk_buff *skb, struct genl_info *info);
+int devlink_nl_notify_filter_set_doit(struct sk_buff *skb,
+				      struct genl_info *info);
 
 #endif /* _LINUX_DEVLINK_GEN_H */
diff --git a/tools/net/ynl/generated/devlink-user.c b/tools/net/ynl/generated/devlink-user.c
index bc5065bd99b2..cd5f70eadf5b 100644
--- a/tools/net/ynl/generated/devlink-user.c
+++ b/tools/net/ynl/generated/devlink-user.c
@@ -6830,6 +6830,37 @@ int devlink_selftests_run(struct ynl_sock *ys,
 	return 0;
 }
 
+/* ============== DEVLINK_CMD_NOTIFY_FILTER_SET ============== */
+/* DEVLINK_CMD_NOTIFY_FILTER_SET - do */
+void
+devlink_notify_filter_set_req_free(struct devlink_notify_filter_set_req *req)
+{
+	free(req->bus_name);
+	free(req->dev_name);
+	free(req);
+}
+
+int devlink_notify_filter_set(struct ynl_sock *ys,
+			      struct devlink_notify_filter_set_req *req)
+{
+	struct nlmsghdr *nlh;
+	int err;
+
+	nlh = ynl_gemsg_start_req(ys, ys->family_id, DEVLINK_CMD_NOTIFY_FILTER_SET, 1);
+	ys->req_policy = &devlink_nest;
+
+	if (req->_present.bus_name_len)
+		mnl_attr_put_strz(nlh, DEVLINK_ATTR_BUS_NAME, req->bus_name);
+	if (req->_present.dev_name_len)
+		mnl_attr_put_strz(nlh, DEVLINK_ATTR_DEV_NAME, req->dev_name);
+
+	err = ynl_exec(ys, nlh, NULL);
+	if (err < 0)
+		return -1;
+
+	return 0;
+}
+
 const struct ynl_family ynl_devlink_family =  {
 	.name		= "devlink",
 };
diff --git a/tools/net/ynl/generated/devlink-user.h b/tools/net/ynl/generated/devlink-user.h
index 1db4edc36eaa..e5d79b824a67 100644
--- a/tools/net/ynl/generated/devlink-user.h
+++ b/tools/net/ynl/generated/devlink-user.h
@@ -5252,4 +5252,51 @@ devlink_selftests_run_req_set_selftests_flash(struct devlink_selftests_run_req *
 int devlink_selftests_run(struct ynl_sock *ys,
 			  struct devlink_selftests_run_req *req);
 
+/* ============== DEVLINK_CMD_NOTIFY_FILTER_SET ============== */
+/* DEVLINK_CMD_NOTIFY_FILTER_SET - do */
+struct devlink_notify_filter_set_req {
+	struct {
+		__u32 bus_name_len;
+		__u32 dev_name_len;
+	} _present;
+
+	char *bus_name;
+	char *dev_name;
+};
+
+static inline struct devlink_notify_filter_set_req *
+devlink_notify_filter_set_req_alloc(void)
+{
+	return calloc(1, sizeof(struct devlink_notify_filter_set_req));
+}
+void
+devlink_notify_filter_set_req_free(struct devlink_notify_filter_set_req *req);
+
+static inline void
+devlink_notify_filter_set_req_set_bus_name(struct devlink_notify_filter_set_req *req,
+					   const char *bus_name)
+{
+	free(req->bus_name);
+	req->_present.bus_name_len = strlen(bus_name);
+	req->bus_name = malloc(req->_present.bus_name_len + 1);
+	memcpy(req->bus_name, bus_name, req->_present.bus_name_len);
+	req->bus_name[req->_present.bus_name_len] = 0;
+}
+static inline void
+devlink_notify_filter_set_req_set_dev_name(struct devlink_notify_filter_set_req *req,
+					   const char *dev_name)
+{
+	free(req->dev_name);
+	req->_present.dev_name_len = strlen(dev_name);
+	req->dev_name = malloc(req->_present.dev_name_len + 1);
+	memcpy(req->dev_name, dev_name, req->_present.dev_name_len);
+	req->dev_name[req->_present.dev_name_len] = 0;
+}
+
+/*
+ * Set notification messages socket filter.
+ */
+int devlink_notify_filter_set(struct ynl_sock *ys,
+			      struct devlink_notify_filter_set_req *req);
+
 #endif /* _LINUX_DEVLINK_GEN_H */
-- 
2.41.0

[patch net-next v3 9/9] devlink: extend multicast filtering by port index

[Jiri Pirko]

From: Jiri Pirko <jiri@nvidia.com>

Expose the previously introduced notification multicast messages
filtering infrastructure and allow the user to select messages using
port index.

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
---
 Documentation/netlink/specs/devlink.yaml |  1 +
 net/devlink/devl_internal.h              |  9 +++++++++
 net/devlink/health.c                     |  6 +++++-
 net/devlink/netlink.c                    | 10 +++++++++-
 net/devlink/netlink_gen.c                |  5 +++--
 net/devlink/port.c                       |  5 ++++-
 tools/net/ynl/generated/devlink-user.c   |  2 ++
 tools/net/ynl/generated/devlink-user.h   |  9 +++++++++
 8 files changed, 42 insertions(+), 5 deletions(-)

diff --git a/Documentation/netlink/specs/devlink.yaml b/Documentation/netlink/specs/devlink.yaml
index cc4991cbce83..49d4fbf3fe44 100644
--- a/Documentation/netlink/specs/devlink.yaml
+++ b/Documentation/netlink/specs/devlink.yaml
@@ -2065,3 +2065,4 @@ operations:
           attributes:
             - bus-name
             - dev-name
+            - port-index
diff --git a/net/devlink/devl_internal.h b/net/devlink/devl_internal.h
index 0ee0bcdd4a7d..3ed7808013f1 100644
--- a/net/devlink/devl_internal.h
+++ b/net/devlink/devl_internal.h
@@ -181,6 +181,8 @@ static inline bool devlink_nl_notify_need(struct devlink *devlink)
 struct devlink_obj_desc {
 	const char *bus_name;
 	const char *dev_name;
+	unsigned int port_index;
+	bool port_index_valid;
 	long data[];
 };
 
@@ -192,6 +194,13 @@ static inline void devlink_nl_obj_desc_init(struct devlink_obj_desc *desc,
 	desc->dev_name = dev_name(devlink->dev);
 }
 
+static inline void devlink_nl_obj_desc_port_set(struct devlink_obj_desc *desc,
+						struct devlink_port *devlink_port)
+{
+	desc->port_index = devlink_port->index;
+	desc->port_index_valid = true;
+}
+
 int devlink_nl_notify_filter(struct sock *dsk, struct sk_buff *skb, void *data);
 
 static inline void devlink_nl_notify_send_desc(struct devlink *devlink,
diff --git a/net/devlink/health.c b/net/devlink/health.c
index 2f06e4ddbf3b..0e96d26203f1 100644
--- a/net/devlink/health.c
+++ b/net/devlink/health.c
@@ -490,6 +490,7 @@ static void devlink_recover_notify(struct devlink_health_reporter *reporter,
 				   enum devlink_command cmd)
 {
 	struct devlink *devlink = reporter->devlink;
+	struct devlink_obj_desc desc;
 	struct sk_buff *msg;
 	int err;
 
@@ -509,7 +510,10 @@ static void devlink_recover_notify(struct devlink_health_reporter *reporter,
 		return;
 	}
 
-	devlink_nl_notify_send(devlink, msg);
+	devlink_nl_obj_desc_init(&desc, devlink);
+	if (reporter->devlink_port)
+		devlink_nl_obj_desc_port_set(&desc, reporter->devlink_port);
+	devlink_nl_notify_send_desc(devlink, msg, &desc);
 }
 
 void
diff --git a/net/devlink/netlink.c b/net/devlink/netlink.c
index 738e2f340ab9..6c033d1f7e64 100644
--- a/net/devlink/netlink.c
+++ b/net/devlink/netlink.c
@@ -46,11 +46,16 @@ int devlink_nl_notify_filter_set_doit(struct sk_buff *skb,
 		flt->dev_name = pos;
 	}
 
+	if (attrs[DEVLINK_ATTR_PORT_INDEX]) {
+		flt->port_index = nla_get_u32(attrs[DEVLINK_ATTR_PORT_INDEX]);
+		flt->port_index_valid = true;
+	}
+
 	/* Free the existing filter if any. */
 	kfree(sk->sk_user_data);
 
 	/* Don't attach empty filter. */
-	if (!flt->bus_name && !flt->dev_name) {
+	if (!flt->bus_name && !flt->dev_name && !flt->port_index_valid) {
 		kfree(flt);
 		flt = NULL;
 	}
@@ -68,6 +73,9 @@ static bool devlink_obj_desc_match(const struct devlink_obj_desc *desc,
 	if (desc->dev_name && flt->dev_name &&
 	    strcmp(desc->dev_name, flt->dev_name))
 		return false;
+	if (desc->port_index_valid && flt->port_index_valid &&
+	    desc->port_index != flt->port_index)
+		return false;
 	return true;
 }
 
diff --git a/net/devlink/netlink_gen.c b/net/devlink/netlink_gen.c
index f207f3fc7e20..b3f37e3c1b64 100644
--- a/net/devlink/netlink_gen.c
+++ b/net/devlink/netlink_gen.c
@@ -561,9 +561,10 @@ static const struct nla_policy devlink_selftests_run_nl_policy[DEVLINK_ATTR_SELF
 };
 
 /* DEVLINK_CMD_NOTIFY_FILTER_SET - do */
-static const struct nla_policy devlink_notify_filter_set_nl_policy[DEVLINK_ATTR_DEV_NAME + 1] = {
+static const struct nla_policy devlink_notify_filter_set_nl_policy[DEVLINK_ATTR_PORT_INDEX + 1] = {
 	[DEVLINK_ATTR_BUS_NAME] = { .type = NLA_NUL_STRING, },
 	[DEVLINK_ATTR_DEV_NAME] = { .type = NLA_NUL_STRING, },
+	[DEVLINK_ATTR_PORT_INDEX] = { .type = NLA_U32, },
 };
 
 /* Ops table for devlink */
@@ -1243,7 +1244,7 @@ const struct genl_split_ops devlink_nl_ops[74] = {
 		.cmd		= DEVLINK_CMD_NOTIFY_FILTER_SET,
 		.doit		= devlink_nl_notify_filter_set_doit,
 		.policy		= devlink_notify_filter_set_nl_policy,
-		.maxattr	= DEVLINK_ATTR_DEV_NAME,
+		.maxattr	= DEVLINK_ATTR_PORT_INDEX,
 		.flags		= GENL_CMD_CAP_DO,
 	},
 };
diff --git a/net/devlink/port.c b/net/devlink/port.c
index 758df3000a1b..62e54e152ecf 100644
--- a/net/devlink/port.c
+++ b/net/devlink/port.c
@@ -507,6 +507,7 @@ static void devlink_port_notify(struct devlink_port *devlink_port,
 				enum devlink_command cmd)
 {
 	struct devlink *devlink = devlink_port->devlink;
+	struct devlink_obj_desc desc;
 	struct sk_buff *msg;
 	int err;
 
@@ -525,7 +526,9 @@ static void devlink_port_notify(struct devlink_port *devlink_port,
 		return;
 	}
 
-	devlink_nl_notify_send(devlink, msg);
+	devlink_nl_obj_desc_init(&desc, devlink);
+	devlink_nl_obj_desc_port_set(&desc, devlink_port);
+	devlink_nl_notify_send_desc(devlink, msg, &desc);
 }
 
 static void devlink_ports_notify(struct devlink *devlink,
diff --git a/tools/net/ynl/generated/devlink-user.c b/tools/net/ynl/generated/devlink-user.c
index cd5f70eadf5b..86392da0b52c 100644
--- a/tools/net/ynl/generated/devlink-user.c
+++ b/tools/net/ynl/generated/devlink-user.c
@@ -6853,6 +6853,8 @@ int devlink_notify_filter_set(struct ynl_sock *ys,
 		mnl_attr_put_strz(nlh, DEVLINK_ATTR_BUS_NAME, req->bus_name);
 	if (req->_present.dev_name_len)
 		mnl_attr_put_strz(nlh, DEVLINK_ATTR_DEV_NAME, req->dev_name);
+	if (req->_present.port_index)
+		mnl_attr_put_u32(nlh, DEVLINK_ATTR_PORT_INDEX, req->port_index);
 
 	err = ynl_exec(ys, nlh, NULL);
 	if (err < 0)
diff --git a/tools/net/ynl/generated/devlink-user.h b/tools/net/ynl/generated/devlink-user.h
index e5d79b824a67..b96837663e6e 100644
--- a/tools/net/ynl/generated/devlink-user.h
+++ b/tools/net/ynl/generated/devlink-user.h
@@ -5258,10 +5258,12 @@ struct devlink_notify_filter_set_req {
 	struct {
 		__u32 bus_name_len;
 		__u32 dev_name_len;
+		__u32 port_index:1;
 	} _present;
 
 	char *bus_name;
 	char *dev_name;
+	__u32 port_index;
 };
 
 static inline struct devlink_notify_filter_set_req *
@@ -5292,6 +5294,13 @@ devlink_notify_filter_set_req_set_dev_name(struct devlink_notify_filter_set_req
 	memcpy(req->dev_name, dev_name, req->_present.dev_name_len);
 	req->dev_name[req->_present.dev_name_len] = 0;
 }
+static inline void
+devlink_notify_filter_set_req_set_port_index(struct devlink_notify_filter_set_req *req,
+					     __u32 port_index)
+{
+	req->_present.port_index = 1;
+	req->port_index = port_index;
+}
 
 /*
  * Set notification messages socket filter.
-- 
2.41.0

Re: [patch net-next v3 0/9] devlink: introduce notifications filtering

[Jakub Kicinski]

On Mon, 20 Nov 2023 09:46:48 +0100 Jiri Pirko wrote:
> Currently the user listening on a socket for devlink notifications
> gets always all messages for all existing devlink instances and objects,
> even if he is interested only in one of those. That may cause
> unnecessary overhead on setups with thousands of instances present.

There's a conflict, probably with mlxsw's reset changes.
Please respin.
-- 
pw-bot: cr

Re: [patch net-next v3 5/9] genetlink: implement release callback and free sk_user_data there

[Jakub Kicinski]

On Mon, 20 Nov 2023 09:46:53 +0100 Jiri Pirko wrote:
> If any generic netlink family would like to allocate data store the
> pointer to sk_user_data, there is no way to do cleanup in the family
> code.

How is this supposed to work?

genetlink sockets are not bound to a family. User can use a single
socket to subscribe to notifications from all families and presumably
each one of the would interpret sk->sk_user_data as their own state?

You need to store the state locally in the family, keyed
on pid, and free it using the NETLINK_URELEASE notifier...

Re: [patch net-next v3 8/9] devlink: add a command to set notification filter and use it for multicasts

[Jakub Kicinski]

On Mon, 20 Nov 2023 09:46:56 +0100 Jiri Pirko wrote:
> +	if (attrs[DEVLINK_ATTR_BUS_NAME])
> +		data_size += nla_len(attrs[DEVLINK_ATTR_BUS_NAME]) + 1;
> +	if (attrs[DEVLINK_ATTR_DEV_NAME])
> +		data_size += nla_len(attrs[DEVLINK_ATTR_DEV_NAME]) + 1;

> +	/* Don't attach empty filter. */
> +	if (!flt->bus_name && !flt->dev_name) {

Should the attrs be checked with GENL_REQ_ATTR_CHECK() then?

Re: [patch net-next v3 8/9] devlink: add a command to set notification filter and use it for multicasts

[Jiri Pirko]

Tue, Nov 21, 2023 at 03:51:23AM CET, kuba@kernel.org wrote:
>On Mon, 20 Nov 2023 09:46:56 +0100 Jiri Pirko wrote:
>> +	if (attrs[DEVLINK_ATTR_BUS_NAME])
>> +		data_size += nla_len(attrs[DEVLINK_ATTR_BUS_NAME]) + 1;
>> +	if (attrs[DEVLINK_ATTR_DEV_NAME])
>> +		data_size += nla_len(attrs[DEVLINK_ATTR_DEV_NAME]) + 1;
>
>> +	/* Don't attach empty filter. */
>> +	if (!flt->bus_name && !flt->dev_name) {
>
>Should the attrs be checked with GENL_REQ_ATTR_CHECK() then?

No, they are all optional. This is for the case the user passes empty
message, that clears the filter.

Re: [patch net-next v3 5/9] genetlink: implement release callback and free sk_user_data there

[Jiri Pirko]

Tue, Nov 21, 2023 at 03:50:22AM CET, kuba@kernel.org wrote:
>On Mon, 20 Nov 2023 09:46:53 +0100 Jiri Pirko wrote:
>> If any generic netlink family would like to allocate data store the
>> pointer to sk_user_data, there is no way to do cleanup in the family
>> code.
>
>How is this supposed to work?
>
>genetlink sockets are not bound to a family. User can use a single
>socket to subscribe to notifications from all families and presumably
>each one of the would interpret sk->sk_user_data as their own state?
>
>You need to store the state locally in the family, keyed
>on pid, and free it using the NETLINK_URELEASE notifier...

Ah, correct. Will fix.

Re: [patch net-next v3 5/9] genetlink: implement release callback and free sk_user_data there

[Jiri Pirko]

Tue, Nov 21, 2023 at 03:50:22AM CET, kuba@kernel.org wrote:
>On Mon, 20 Nov 2023 09:46:53 +0100 Jiri Pirko wrote:
>> If any generic netlink family would like to allocate data store the
>> pointer to sk_user_data, there is no way to do cleanup in the family
>> code.
>
>How is this supposed to work?
>
>genetlink sockets are not bound to a family. User can use a single
>socket to subscribe to notifications from all families and presumably
>each one of the would interpret sk->sk_user_data as their own state?
>
>You need to store the state locally in the family, keyed
>on pid, and free it using the NETLINK_URELEASE notifier...

Well, pin can have 2 sockets of different config. I think that sk/family
tuple is needed. I'm exploring a possibility to have genetlink
sk->sk_user_data used to store the hashlist keyed by the sk/family tuple.

Re: [patch net-next v3 5/9] genetlink: implement release callback and free sk_user_data there

[Jakub Kicinski]

On Tue, 21 Nov 2023 14:12:55 +0100 Jiri Pirko wrote:
> >How is this supposed to work?
> >
> >genetlink sockets are not bound to a family. User can use a single
> >socket to subscribe to notifications from all families and presumably
> >each one of the would interpret sk->sk_user_data as their own state?
> >
> >You need to store the state locally in the family, keyed
> >on pid, and free it using the NETLINK_URELEASE notifier...  
> 
> Well, pin can have 2 sockets of different config. I think that sk/family
> tuple is needed. I'm exploring a possibility to have genetlink
> sk->sk_user_data used to store the hashlist keyed by the sk/family tuple.

If you're doing it centrally, please put the state as a new field in
the netlink socket. sk_user_data is for the user.

Also let's start with a list, practically speaking using one socket 
in many families should be very rare.

Re: [patch net-next v3 5/9] genetlink: implement release callback and free sk_user_data there

[Jiri Pirko]

Tue, Nov 21, 2023 at 06:55:12PM CET, kuba@kernel.org wrote:
>On Tue, 21 Nov 2023 14:12:55 +0100 Jiri Pirko wrote:
>> >How is this supposed to work?
>> >
>> >genetlink sockets are not bound to a family. User can use a single
>> >socket to subscribe to notifications from all families and presumably
>> >each one of the would interpret sk->sk_user_data as their own state?
>> >
>> >You need to store the state locally in the family, keyed
>> >on pid, and free it using the NETLINK_URELEASE notifier...  
>> 
>> Well, pin can have 2 sockets of different config. I think that sk/family
>> tuple is needed. I'm exploring a possibility to have genetlink
>> sk->sk_user_data used to store the hashlist keyed by the sk/family tuple.
>
>If you're doing it centrally, please put the state as a new field in
>the netlink socket. sk_user_data is for the user.

I planned to use sk_user_data. What do you mean it is for the user?
I see it is already used for similar usecase by connector for example:

$ git grep sk_user_data drivers/connector/
drivers/connector/cn_proc.c:    if (!dsk || !dsk->sk_user_data || !data)
drivers/connector/cn_proc.c:    val = ((struct proc_input *)(dsk->sk_user_data))->event_type;
drivers/connector/cn_proc.c:    mc_op = ((struct proc_input *)(dsk->sk_user_data))->mcast_op;
drivers/connector/cn_proc.c:            if (sk->sk_user_data == NULL) {
drivers/connector/cn_proc.c:                    sk->sk_user_data = kzalloc(sizeof(struct proc_input),
drivers/connector/cn_proc.c:                    if (sk->sk_user_data == NULL) {
drivers/connector/cn_proc.c:                    ((struct proc_input *)(sk->sk_user_data))->mcast_op;
drivers/connector/cn_proc.c:            ((struct proc_input *)(sk->sk_user_data))->event_type =
drivers/connector/cn_proc.c:            ((struct proc_input *)(sk->sk_user_data))->mcast_op = mc_op;
drivers/connector/cn_proc.c:            ((struct proc_input *)(sk->sk_user_data))->event_type =
drivers/connector/connector.c:          kfree(sk->sk_user_data);
drivers/connector/connector.c:          sk->sk_user_data = NULL;


>
>Also let's start with a list, practically speaking using one socket 
>in many families should be very rare.

Okay.

Re: [patch net-next v3 5/9] genetlink: implement release callback and free sk_user_data there

[Jakub Kicinski]

On Wed, 22 Nov 2023 10:29:44 +0100 Jiri Pirko wrote:
> >If you're doing it centrally, please put the state as a new field in
> >the netlink socket. sk_user_data is for the user.  
> 
> I planned to use sk_user_data. What do you mean it is for the user?
> I see it is already used for similar usecase by connector for example:

I'm pretty sure I complained when it was being added. Long story.
AFAIU user as in if the socket is opened by a kernel module, the kernel
module is the user. There's no need to use this field for the
implementation since the implementation can simply extend its 
own structure to add a properly typed field.

Re: [patch net-next v3 5/9] genetlink: implement release callback and free sk_user_data there

[Jiri Pirko]

Wed, Nov 22, 2023 at 06:08:20PM CET, kuba@kernel.org wrote:
>On Wed, 22 Nov 2023 10:29:44 +0100 Jiri Pirko wrote:
>> >If you're doing it centrally, please put the state as a new field in
>> >the netlink socket. sk_user_data is for the user.  
>> 
>> I planned to use sk_user_data. What do you mean it is for the user?
>> I see it is already used for similar usecase by connector for example:
>
>I'm pretty sure I complained when it was being added. Long story.
>AFAIU user as in if the socket is opened by a kernel module, the kernel
>module is the user. There's no need to use this field for the
>implementation since the implementation can simply extend its 
>own structure to add a properly typed field.

Okay, excuse me, as always I'm slow here. What structure are
you refering to?

Thanks!

Re: [patch net-next v3 5/9] genetlink: implement release callback and free sk_user_data there

[Jakub Kicinski]

On Wed, 22 Nov 2023 19:20:58 +0100 Jiri Pirko wrote:
> >I'm pretty sure I complained when it was being added. Long story.
> >AFAIU user as in if the socket is opened by a kernel module, the kernel
> >module is the user. There's no need to use this field for the
> >implementation since the implementation can simply extend its 
> >own structure to add a properly typed field.  
> 
> Okay, excuse me, as always I'm slow here. What structure are
> you refering to?

struct netlink_sock. Technically it may be a little cleaner to wrap 
that in another struct that will be genetlink specific. But that's
a larger surgery for relatively little benefit at this stage.

Re: [patch net-next v3 5/9] genetlink: implement release callback and free sk_user_data there

[Jiri Pirko]

Wed, Nov 22, 2023 at 08:50:55PM CET, kuba@kernel.org wrote:
>On Wed, 22 Nov 2023 19:20:58 +0100 Jiri Pirko wrote:
>> >I'm pretty sure I complained when it was being added. Long story.
>> >AFAIU user as in if the socket is opened by a kernel module, the kernel
>> >module is the user. There's no need to use this field for the
>> >implementation since the implementation can simply extend its 
>> >own structure to add a properly typed field.  
>> 
>> Okay, excuse me, as always I'm slow here. What structure are
>> you refering to?
>
>struct netlink_sock. Technically it may be a little cleaner to wrap 
>that in another struct that will be genetlink specific. But that's
>a larger surgery for relatively little benefit at this stage.

Got it. Will explore that path. Thanks!

Re: [patch net-next v3 5/9] genetlink: implement release callback and free sk_user_data there

[Jiri Pirko]

Wed, Nov 22, 2023 at 06:08:20PM CET, kuba@kernel.org wrote:
>On Wed, 22 Nov 2023 10:29:44 +0100 Jiri Pirko wrote:
>> >If you're doing it centrally, please put the state as a new field in
>> >the netlink socket. sk_user_data is for the user.  
>> 
>> I planned to use sk_user_data. What do you mean it is for the user?
>> I see it is already used for similar usecase by connector for example:
>
>I'm pretty sure I complained when it was being added. Long story.
>AFAIU user as in if the socket is opened by a kernel module, the kernel
>module is the user. There's no need to use this field for the
>implementation since the implementation can simply extend its 
>own structure to add a properly typed field.

In this case, the socket is not opened by kernel, but it is opened by
the userspace app.

I basically need to have per-user-sk pointer somewhere I'm not clear why
to put it in struct netlink_sock when I can use sk_user_data which is
already there. From the usage of this pointer in kernel, I understand
this is exactly the reason to have it.

Are you afraid of a collision of sk_user_data use with somebody else
here? I don't see how that could happen for netlink socket.

Re: [patch net-next v3 5/9] genetlink: implement release callback and free sk_user_data there

[Jakub Kicinski]

On Thu, 23 Nov 2023 11:32:07 +0100 Jiri Pirko wrote:
> In this case, the socket is not opened by kernel, but it is opened by
> the userspace app.
> 
> I basically need to have per-user-sk pointer somewhere I'm not clear why
> to put it in struct netlink_sock when I can use sk_user_data which is
> already there. From the usage of this pointer in kernel, I understand
> this is exactly the reason to have it.

Various people stuck various things in that pointer just because,
it's a mess. IIUC the initial motivation for it is that someone
like NFS opens a kernel socket and needs to put private data
somewhere. A kernel user gets a callback for a socket, like data
ready, and needs to find their private state.

> Are you afraid of a collision of sk_user_data use with somebody else
> here? I don't see how that could happen for netlink socket.

Normally upper layer wraps the socket struct in its own struct. 
Look at the struct nesting for TCP or any other bona fide protocol. 
genetlink will benefit from having socket state, I bet it wasn't done
that way from the start because Jamal/Thomas were told to start small.

Please add a properly typed field to the netlink struct, unless you
have technical reasons not to.

Re: [patch net-next v3 5/9] genetlink: implement release callback and free sk_user_data there

[Jiri Pirko]

Thu, Nov 23, 2023 at 05:24:08PM CET, kuba@kernel.org wrote:
>On Thu, 23 Nov 2023 11:32:07 +0100 Jiri Pirko wrote:
>> In this case, the socket is not opened by kernel, but it is opened by
>> the userspace app.
>> 
>> I basically need to have per-user-sk pointer somewhere I'm not clear why
>> to put it in struct netlink_sock when I can use sk_user_data which is
>> already there. From the usage of this pointer in kernel, I understand
>> this is exactly the reason to have it.
>
>Various people stuck various things in that pointer just because,
>it's a mess. IIUC the initial motivation for it is that someone
>like NFS opens a kernel socket and needs to put private data
>somewhere. A kernel user gets a callback for a socket, like data
>ready, and needs to find their private state.
>
>> Are you afraid of a collision of sk_user_data use with somebody else
>> here? I don't see how that could happen for netlink socket.
>
>Normally upper layer wraps the socket struct in its own struct. 
>Look at the struct nesting for TCP or any other bona fide protocol. 
>genetlink will benefit from having socket state, I bet it wasn't done
>that way from the start because Jamal/Thomas were told to start small.
>
>Please add a properly typed field to the netlink struct, unless you
>have technical reasons not to.

Okay.