From patchwork Mon Feb 12 16:16:13 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stanislaw Gruszka X-Patchwork-Id: 772587 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 25C123D0B6; Mon, 12 Feb 2024 16:16:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.17 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707754596; cv=none; b=Qzaksj99MLxyIx5rucTQDy8wdfig4uRuqydWBpWJeyFpg9LLn5OjkbR/rKwxzoLqTi3Ja9bKVwcG5DGNxdRNMxLGPPQhKL4159aMZ/39EHy9VakRjrMKkMxsBBP3bbfXzudbkH45kO6BUykY7GhVwRFyU7c+SkVmbcip+lo3XV0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707754596; c=relaxed/simple; bh=TJ8XPREa5fooi39Kbtq0nhln3uQjJqP9rhCqY3fIHHI=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=NV6Rz9n4EAONzQJ7aa7Mjyt+HTvXJl3pSoifjMrM1ThlrqT9DBI7DeemYFVFA3dVwwvAw16kU1qm2bW01fP+9zFhsjitRrzlJ21MLCR+BsnnvaPGDLZCVb5gpNyYOdoSYTX5wKgKecQtcFZm1XoWhp1nHJWZcPDLiBcVmqhm/z8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=eM6K60/P; arc=none smtp.client-ip=198.175.65.17 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="eM6K60/P" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1707754595; x=1739290595; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=TJ8XPREa5fooi39Kbtq0nhln3uQjJqP9rhCqY3fIHHI=; b=eM6K60/PG1sAlv71wNDZ6Q6jogtnxgXK0cU0lUUIvajH5Sk+IzmNmI+T siDxkXW0XvkqLS3gPk7L1zkm4zgkfeBnkeahVGUPCr02hFwihv9qqgGfA RAg7g4wwLX4D0swUAkYLSd7zcI34mkNZ0AxUlZiWT5xUSOcxy/ujrLcsL jRrwDvEYBkuxkwEciaaGb2K7RT1bqKydStMIxNbC4B5exAhFi7bFvN3Z6 ljPBNvfJtSDCVdhwVF8+cJrVWNeZLyw9gxxdSdkxPSveADoj0SwLoTpZc j0bnHYZAwkhjpjVPSEdWltdufaeG6y4zS9hrvXOhK4UB3lCIsY2mJbk5V g==; X-IronPort-AV: E=McAfee;i="6600,9927,10982"; a="1873151" X-IronPort-AV: E=Sophos;i="6.06,264,1705392000"; d="scan'208";a="1873151" Received: from fmviesa005.fm.intel.com ([10.60.135.145]) by orvoesa109.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Feb 2024 08:16:34 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.06,264,1705392000"; d="scan'208";a="7258733" Received: from sgruszka-mobl.ger.corp.intel.com (HELO localhost) ([10.252.44.2]) by fmviesa005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Feb 2024 08:16:31 -0800 From: Stanislaw Gruszka To: linux-pm@vger.kernel.org Cc: "Rafael J. Wysocki" , Srinivas Pandruvada , Ricardo Neri , Daniel Lezcano , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Jiri Pirko , Johannes Berg , Florian Westphal , netdev@vger.kernel.org Subject: [PATCH v4 1/3] genetlink: Add per family bind/unbind callbacks Date: Mon, 12 Feb 2024 17:16:13 +0100 Message-Id: <20240212161615.161935-2-stanislaw.gruszka@linux.intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240212161615.161935-1-stanislaw.gruszka@linux.intel.com> References: <20240212161615.161935-1-stanislaw.gruszka@linux.intel.com> Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 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 Signed-off-by: Stanislaw Gruszka --- include/net/genetlink.h | 4 ++++ net/netlink/genetlink.c | 30 ++++++++++++++++++++++++++++++ 2 files changed, 34 insertions(+) diff --git a/include/net/genetlink.h b/include/net/genetlink.h index e61469129402..ecadba836ae5 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 8c7af02f8454..50ec599a5cff 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, };