From patchwork Sun Jan 11 20:52:49 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Richard Weinberger X-Patchwork-Id: 427522 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 8634D1401D0 for ; Mon, 12 Jan 2015 07:54:22 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752472AbbAKUyF (ORCPT ); Sun, 11 Jan 2015 15:54:05 -0500 Received: from mail.sigma-star.at ([95.130.255.111]:14386 "EHLO mail.sigma-star.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751712AbbAKUxC (ORCPT ); Sun, 11 Jan 2015 15:53:02 -0500 Received: from localhost (localhost.localdomain [127.0.0.1]) by mail.sigma-star.at (Postfix) with ESMTP id A60B024F8005; Sun, 11 Jan 2015 21:52:58 +0100 (CET) X-Virus-Scanned: amavisd-new at mail.sigma-star.at Received: from localhost.localdomain (chello213047235169.tirol.surfer.at [213.47.235.169]) by mail.sigma-star.at (Postfix) with ESMTPSA id B26AC24F8002; Sun, 11 Jan 2015 21:52:56 +0100 (CET) From: Richard Weinberger To: davem@davemloft.net Cc: coreteam@netfilter.org, netfilter-devel@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, bhutchings@solarflare.com, john.fastabend@gmail.com, herbert@gondor.apana.org.au, vyasevic@redhat.com, jiri@resnulli.us, vfalico@gmail.com, therbert@google.com, edumazet@google.com, yoshfuji@linux-ipv6.org, jmorris@namei.org, kuznet@ms2.inr.ac.ru, kadlec@blackhole.kfki.hu, kaber@trash.net, pablo@netfilter.org, kay@vrfy.org, stephen@networkplumber.org, Richard Weinberger Subject: [PATCH 1/3] net: Make interface aliases available for general usage Date: Sun, 11 Jan 2015 21:52:49 +0100 Message-Id: <1421009571-5279-2-git-send-email-richard@nod.at> X-Mailer: git-send-email 1.8.4.5 In-Reply-To: <1421009571-5279-1-git-send-email-richard@nod.at> References: <1421009571-5279-1-git-send-email-richard@nod.at> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Allow interface aliases to be used as regular interfaces. Such that a command sequence like this one works: $ ip l set eth0 alias internet $ ip a s internet $ tcpdump -n -i internet Signed-off-by: Richard Weinberger --- include/linux/netdevice.h | 1 + include/net/net_namespace.h | 1 + net/core/dev.c | 52 +++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 54 insertions(+) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 679e6e9..e00b4e2 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1493,6 +1493,7 @@ struct net_device { char name[IFNAMSIZ]; struct hlist_node name_hlist; char *ifalias; + struct hlist_node ifalias_hlist; /* * I/O specific fields * FIXME: Merge these and struct ifmap into one diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h index 2e8756b8..9fa0939 100644 --- a/include/net/net_namespace.h +++ b/include/net/net_namespace.h @@ -76,6 +76,7 @@ struct net { struct list_head dev_base_head; struct hlist_head *dev_name_head; struct hlist_head *dev_index_head; + struct hlist_head *dev_ifalias_head; unsigned int dev_base_seq; /* protected by rtnl_mutex */ int ifindex; unsigned int dev_unreg_count; diff --git a/net/core/dev.c b/net/core/dev.c index 683d493..2551b03 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -202,6 +202,14 @@ static inline struct hlist_head *dev_index_hash(struct net *net, int ifindex) return &net->dev_index_head[ifindex & (NETDEV_HASHENTRIES - 1)]; } +static inline struct hlist_head *dev_ifalias_hash(struct net *net, + const char *ifalias) +{ + unsigned int hash = full_name_hash(ifalias, strnlen(ifalias, IFALIASZ)); + + return &net->dev_ifalias_head[hash_32(hash, NETDEV_HASHBITS)]; +} + static inline void rps_lock(struct softnet_data *sd) { #ifdef CONFIG_RPS @@ -228,6 +236,9 @@ static void list_netdevice(struct net_device *dev) hlist_add_head_rcu(&dev->name_hlist, dev_name_hash(net, dev->name)); hlist_add_head_rcu(&dev->index_hlist, dev_index_hash(net, dev->ifindex)); + if (dev->ifalias) + hlist_add_head_rcu(&dev->ifalias_hlist, + dev_ifalias_hash(net, dev->ifalias)); write_unlock_bh(&dev_base_lock); dev_base_seq_inc(net); @@ -245,6 +256,8 @@ static void unlist_netdevice(struct net_device *dev) list_del_rcu(&dev->dev_list); hlist_del_rcu(&dev->name_hlist); hlist_del_rcu(&dev->index_hlist); + if (dev->ifalias) + hlist_del_rcu(&dev->ifalias_hlist); write_unlock_bh(&dev_base_lock); dev_base_seq_inc(dev_net(dev)); @@ -679,6 +692,11 @@ struct net_device *__dev_get_by_name(struct net *net, const char *name) if (!strncmp(dev->name, name, IFNAMSIZ)) return dev; + head = dev_ifalias_hash(net, name); + hlist_for_each_entry(dev, head, ifalias_hlist) + if (dev->ifalias && !strncmp(dev->ifalias, name, IFALIASZ)) + return dev; + return NULL; } EXPORT_SYMBOL(__dev_get_by_name); @@ -704,6 +722,11 @@ struct net_device *dev_get_by_name_rcu(struct net *net, const char *name) if (!strncmp(dev->name, name, IFNAMSIZ)) return dev; + head = dev_ifalias_hash(net, name); + hlist_for_each_entry_rcu(dev, head, ifalias_hlist) + if (dev->ifalias && !strncmp(dev->ifalias, name, IFALIASZ)) + return dev; + return NULL; } EXPORT_SYMBOL(dev_get_by_name_rcu); @@ -1169,6 +1192,20 @@ rollback: return err; } +static void __hlist_del_alias(struct net_device *dev) +{ + write_lock_bh(&dev_base_lock); + hlist_del_rcu(&dev->ifalias_hlist); + write_unlock_bh(&dev_base_lock); +} + +static void __hlist_add_alias(struct net_device *dev) +{ + write_lock_bh(&dev_base_lock); + hlist_add_head_rcu(&dev->ifalias_hlist, dev_ifalias_hash(dev_net(dev), dev->ifalias)); + write_unlock_bh(&dev_base_lock); +} + /** * dev_set_alias - change ifalias of a device * @dev: device @@ -1189,15 +1226,24 @@ int dev_set_alias(struct net_device *dev, const char *alias, size_t len) if (!len) { kfree(dev->ifalias); dev->ifalias = NULL; + __hlist_del_alias(dev); return 0; } new_ifalias = krealloc(dev->ifalias, len + 1, GFP_KERNEL); if (!new_ifalias) return -ENOMEM; + + if (dev->ifalias) { + __hlist_del_alias(dev); + synchronize_rcu(); + } + dev->ifalias = new_ifalias; strlcpy(dev->ifalias, alias, len+1); + __hlist_add_alias(dev); + return len; } @@ -7150,8 +7196,14 @@ static int __net_init netdev_init(struct net *net) if (net->dev_index_head == NULL) goto err_idx; + net->dev_ifalias_head = netdev_create_hash(); + if (net->dev_ifalias_head == NULL) + goto err_alias; + return 0; +err_alias: + kfree(net->dev_index_head); err_idx: kfree(net->dev_name_head); err_name: