diff options
| author | Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com> | 2024-02-12 17:16:13 +0100 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2024-02-15 17:49:16 -0800 |
| commit | 3de21a8990d3c2cc507e9cc4ed00f36358d5b93e (patch) | |
| tree | 163b82bef94b2e60ea478a8aeec4128c69cb2b1f | |
| parent | 841c35169323cd833294798e58b9bf63fa4fa1de (diff) | |
| download | linux-for-thermal-genetlink-family-bind-unbind-callbacks.tar.gz | |
genetlink: Add per family bind/unbind callbacksfor-thermal-genetlink-family-bind-unbind-callbacks
Add genetlink family bind()/unbind() callbacks when adding/removing
multicast group to/from netlink client socket via setsockopt() or
bind() syscall.
They can be used to track if consumers of netlink multicast messages
emerge or disappear. Thus, a client implementing callbacks, can now
send events only when there are active consumers, preventing unnecessary
work when none exist.
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20240212161615.161935-2-stanislaw.gruszka@linux.intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | include/net/genetlink.h | 4 | ||||
| -rw-r--r-- | net/netlink/genetlink.c | 30 |
2 files changed, 34 insertions, 0 deletions
diff --git a/include/net/genetlink.h b/include/net/genetlink.h index e61469129402b..ecadba836ae56 100644 --- a/include/net/genetlink.h +++ b/include/net/genetlink.h @@ -41,6 +41,8 @@ struct genl_info; * do additional, common, filtering and return an error * @post_doit: called after an operation's doit callback, it may * undo operations done by pre_doit, for example release locks + * @bind: called when family multicast group is added to a netlink socket + * @unbind: called when family multicast group is removed from a netlink socket * @module: pointer to the owning module (set to THIS_MODULE) * @mcgrps: multicast groups used by this family * @n_mcgrps: number of multicast groups @@ -84,6 +86,8 @@ struct genl_family { void (*post_doit)(const struct genl_split_ops *ops, struct sk_buff *skb, struct genl_info *info); + int (*bind)(int mcgrp); + void (*unbind)(int mcgrp); const struct genl_ops * ops; const struct genl_small_ops *small_ops; const struct genl_split_ops *split_ops; diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c index 8c7af02f84540..50ec599a5cff5 100644 --- a/net/netlink/genetlink.c +++ b/net/netlink/genetlink.c @@ -1836,6 +1836,9 @@ static int genl_bind(struct net *net, int group) !ns_capable(net->user_ns, CAP_SYS_ADMIN)) ret = -EPERM; + if (family->bind) + family->bind(i); + break; } @@ -1843,12 +1846,39 @@ static int genl_bind(struct net *net, int group) return ret; } +static void genl_unbind(struct net *net, int group) +{ + const struct genl_family *family; + unsigned int id; + + down_read(&cb_lock); + + idr_for_each_entry(&genl_fam_idr, family, id) { + int i; + + if (family->n_mcgrps == 0) + continue; + + i = group - family->mcgrp_offset; + if (i < 0 || i >= family->n_mcgrps) + continue; + + if (family->unbind) + family->unbind(i); + + break; + } + + up_read(&cb_lock); +} + 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, + .unbind = genl_unbind, .release = genl_release, }; |