From patchwork Thu Mar 21 13:40:45 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michal Kubecek X-Patchwork-Id: 1060157 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=suse.cz Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 44Q7Jv5g8Fz9s6w for ; Fri, 22 Mar 2019 00:42:55 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728504AbfCUNku (ORCPT ); Thu, 21 Mar 2019 09:40:50 -0400 Received: from mx2.suse.de ([195.135.220.15]:36336 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728478AbfCUNkr (ORCPT ); Thu, 21 Mar 2019 09:40:47 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 97330AFA5; Thu, 21 Mar 2019 13:40:45 +0000 (UTC) Received: by unicorn.suse.cz (Postfix, from userid 1000) id 43C59E00BF; Thu, 21 Mar 2019 14:40:45 +0100 (CET) Message-Id: In-Reply-To: References: From: Michal Kubecek Subject: [PATCH net-next v4 09/22] ethtool: implement EVENT notifications To: David Miller , netdev@vger.kernel.org Cc: Jakub Kicinski , Jiri Pirko , Andrew Lunn , Florian Fainelli , John Linville , linux-kernel@vger.kernel.org Date: Thu, 21 Mar 2019 14:40:45 +0100 (CET) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Three types of netlink notifications are introduced: - ETHA_EVENT_NEWDEV to notify about newly registered network devices - ETHA_EVENT_DELDEV to notify about unregistered network devices - ETHA_EVENT_RENAMEDEV to notify about renamed network device The notifications are triggered by NETDEV_REGISTER, NETDEV_UNREGISTER and NETDEV_CHANGENAME notifiers. These notifications are intended for applications and daemons monitoring ethtool events to allow updating the list of existing devices without having to open another socket for rtnetlink. Signed-off-by: Michal Kubecek --- Documentation/networking/ethtool-netlink.txt | 27 ++++++++ include/uapi/linux/ethtool_netlink.h | 37 +++++++++++ net/ethtool/netlink.c | 65 ++++++++++++++++++++ 3 files changed, 129 insertions(+) diff --git a/Documentation/networking/ethtool-netlink.txt b/Documentation/networking/ethtool-netlink.txt index e97218d820c0..5e5d785fe215 100644 --- a/Documentation/networking/ethtool-netlink.txt +++ b/Documentation/networking/ethtool-netlink.txt @@ -126,6 +126,8 @@ which the request applies. List of message types --------------------- + ETHNL_CMD_EVENT notification only + All constants use ETHNL_CMD_ prefix, usually followed by "GET", "SET" or "ACT" to indicate the type. @@ -137,9 +139,34 @@ messages marked as "response only" in the table above. "Get" messages with NLM_F_DUMP flags and no device identification dump the information for all devices supporting the request. +Type ETHNL_CMD_EVENT is special, these messages are never used in userspace +requests or kernel replies. They are only sent by kernel to sockets listening +to "monitor" multicast group to inform userspace about certain events. + Later sections describe the format and semantics of these request messages. +EVENT +----- + +EVENT messages are only used in kernel multicast notifications. Atributes +correspond to specific event types, the same type can appear multiple times. + + ETHA_EVENT_NEWDEV (nested) new device was registered + ETHA_NEWDEV_DEV (nested) new device + ETHA_EVENT_DELDEV (nested) device was unregistered + ETHA_DELDEV_DEV (nested) removed device + ETHA_EVENT_RENAMEDEV (nested) device was renamed + ETHA_RENAMEDEV_DEV (nested) renamed device + +For ETHA_EVENT_RENAMEDEV, the name ETHA_RENAME_DEV/ETHA_DEV_NAME is the new +name after the rename. + +Userspace application must expect multiple events to be present in one message +and also multiple events of the same type (e.g. two or more newly registered +devices). + + Request translation ------------------- diff --git a/include/uapi/linux/ethtool_netlink.h b/include/uapi/linux/ethtool_netlink.h index 91e4d117957b..988519bc6e37 100644 --- a/include/uapi/linux/ethtool_netlink.h +++ b/include/uapi/linux/ethtool_netlink.h @@ -13,6 +13,7 @@ enum { ETHNL_CMD_NOOP, + ETHNL_CMD_EVENT, /* only for notifications */ __ETHNL_CMD_CNT, ETHNL_CMD_MAX = (__ETHNL_CMD_CNT - 1) @@ -61,6 +62,42 @@ enum { ETHA_BITSET_MAX = (__ETHA_BITSET_CNT - 1) }; +/* events */ + +enum { + ETHA_NEWDEV_UNSPEC, + ETHA_NEWDEV_DEV, /* nest - ETHA_DEV_* */ + + __ETHA_NEWDEV_CNT, + ETHA_NEWDEV_MAX = (__ETHA_NEWDEV_CNT - 1) +}; + +enum { + ETHA_DELDEV_UNSPEC, + ETHA_DELDEV_DEV, /* nest - ETHA_DEV_* */ + + __ETHA_DELDEV_CNT, + ETHA_DELDEV_MAX = (__ETHA_DELDEV_CNT - 1) +}; + +enum { + ETHA_RENAMEDEV_UNSPEC, + ETHA_RENAMEDEV_DEV, /* nest - ETHA_DEV_* */ + + __ETHA_RENAMEDEV_CNT, + ETHA_RENAMEDEV_MAX = (__ETHA_RENAMEDEV_CNT - 1) +}; + +enum { + ETHA_EVENT_UNSPEC, + ETHA_EVENT_NEWDEV, /* nest - ETHA_NEWDEV_* */ + ETHA_EVENT_DELDEV, /* nest - ETHA_DELDEV_* */ + ETHA_EVENT_RENAMEDEV, /* nest - ETHA_RENAMEDEV_* */ + + __ETHA_EVENT_CNT, + ETHA_EVENT_MAX = (__ETHA_EVENT_CNT - 1) +}; + /* generic netlink info */ #define ETHTOOL_GENL_NAME "ethtool" #define ETHTOOL_GENL_VERSION 1 diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c index 0a77de4f339a..9ab23eaea029 100644 --- a/net/ethtool/netlink.c +++ b/net/ethtool/netlink.c @@ -173,6 +173,67 @@ void ethtool_notify(struct net_device *dev, struct netlink_ext_ack *extack, } EXPORT_SYMBOL(ethtool_notify); +/* size of NEWDEV/DELDEV notification */ +static inline unsigned int dev_notify_size(void) +{ + return nla_total_size(dev_ident_size()); +} + +static void ethnl_notify_devlist(struct netdev_notifier_info *info, + u16 ev_type, u16 dev_attr) +{ + struct net_device *dev = netdev_notifier_info_to_dev(info); + struct sk_buff *skb; + struct nlattr *nest; + void *ehdr; + int ret; + + skb = genlmsg_new(dev_notify_size(), GFP_KERNEL); + if (!skb) + return; + ehdr = genlmsg_put(skb, 0, ++ethnl_bcast_seq, ðtool_genl_family, 0, + ETHNL_CMD_EVENT); + if (!ehdr) + goto out_skb; + nest = ethnl_nest_start(skb, ev_type); + if (!nest) + goto out_skb; + ret = ethnl_fill_dev(skb, dev, dev_attr); + if (ret < 0) + goto out_skb; + nla_nest_end(skb, nest); + genlmsg_end(skb, ehdr); + + genlmsg_multicast(ðtool_genl_family, skb, 0, ETHNL_MCGRP_MONITOR, + GFP_KERNEL); + return; +out_skb: + nlmsg_free(skb); +} + +static int ethnl_netdev_event(struct notifier_block *this, unsigned long event, + void *ptr) +{ + switch (event) { + case NETDEV_REGISTER: + ethnl_notify_devlist(ptr, ETHA_EVENT_NEWDEV, ETHA_NEWDEV_DEV); + break; + case NETDEV_UNREGISTER: + ethnl_notify_devlist(ptr, ETHA_EVENT_DELDEV, ETHA_DELDEV_DEV); + break; + case NETDEV_CHANGENAME: + ethnl_notify_devlist(ptr, ETHA_EVENT_RENAMEDEV, + ETHA_RENAMEDEV_DEV); + break; + } + + return NOTIFY_DONE; +} + +static struct notifier_block ethnl_netdev_notifier = { + .notifier_call = ethnl_netdev_event, +}; + /* genetlink setup */ static const struct genl_ops ethtool_genl_ops[] = { @@ -204,6 +265,10 @@ static int __init ethnl_init(void) if (ret < 0) panic("ethtool: could not register genetlink family\n"); + ret = register_netdevice_notifier(ðnl_netdev_notifier); + if (ret < 0) + panic("ethtool: could not register netdev notifier\n"); + return 0; }