From patchwork Thu Nov 2 19:04:38 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Flavio Leitner X-Patchwork-Id: 833505 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@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=) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3ySZKJ3V46z9sNc for ; Fri, 3 Nov 2017 06:05:08 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934221AbdKBTFH (ORCPT ); Thu, 2 Nov 2017 15:05:07 -0400 Received: from mail-qk0-f195.google.com ([209.85.220.195]:49129 "EHLO mail-qk0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932571AbdKBTFF (ORCPT ); Thu, 2 Nov 2017 15:05:05 -0400 Received: by mail-qk0-f195.google.com with SMTP id d67so631629qkg.5 for ; Thu, 02 Nov 2017 12:05:04 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=ieWspAoOvuKVbxxtxmYlnw4wxhFS0+50jCthiVdMbwU=; b=MzbyL/rZvLBRx/ZA1aVa/02XQOVUClfi3QinJhWNemv9Z6VI4EZZ5lWz1drxmyEGDm X2sX6E7lAKX1/9KyaFfSbcMGeDOVriq2bLOW7RaMKTzDlHO0gSLlc/gyqQtgSPRmjHxb SJ3jsZroGrjEyW8fkrM+wOBgrzlgRrVuMHdp+WzJRDTaJ1dsMA+QYa65Oh1unGLweJbq kAHMcZ1iD3cdX35GARLTIPZzIapNW3/96l3DG0vOasoLkV+Z45A1puRDrIp0HirtBxuJ /siGgDf5IMn6bNoI3bkHJ4kOeowkK9M4tlkBIAodb0kTaac668FjMJoAGrjHtQdjTLgh L4Dg== X-Gm-Message-State: AMCzsaXjF6lmZoaWfOErnc2yaENeDIxxvRHy2hmo1Pizng5h3GHpbAOy njtMqsNUQPHndS6rPS0RrpCBL2Lx96c= X-Google-Smtp-Source: ABhQp+Tv9cKZIocfVgsTFA0MSEONxKqbloV4hHgnAo6t7yYGYNNcLx3b8DJ5nujMdjZ1D/av0pQuAw== X-Received: by 10.55.120.131 with SMTP id t125mr6380350qkc.63.1509649502702; Thu, 02 Nov 2017 12:05:02 -0700 (PDT) Received: from localhost ([177.40.123.73]) by smtp.gmail.com with ESMTPSA id e62sm2459526qkb.11.2017.11.02.12.05.01 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 02 Nov 2017 12:05:02 -0700 (PDT) From: Flavio Leitner To: netdev@vger.kernel.org, dev@openvswitch.org Cc: Jiri Benc Subject: [PATCH net-next 3/3] rtnetlink: use netnsid to query interface Date: Thu, 2 Nov 2017 17:04:38 -0200 Message-Id: <20171102190438.2583-4-fbl@redhat.com> X-Mailer: git-send-email 2.13.6 In-Reply-To: <20171102190438.2583-1-fbl@redhat.com> References: <20171102190438.2583-1-fbl@redhat.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Jiri Benc Currently, when an application gets netnsid from the kernel (for example as the result of RTM_GETLINK call on one end of the veth pair), it's not much useful. There's no reliable way to get to the netns fd from the netnsid, nor does any kernel API accept netnsid. Extend the RTM_GETLINK call to also accept netnsid. It will operate on the netns with the given netnsid in such case. Of course, the calling process needs to have enough capabilities in the target name space; for now, require CAP_NET_ADMIN. This can be relaxed in the future. To signal to the calling process that the kernel understood the new IFLA_IF_NETNSID attribute in the query, it will include it in the response. This is needed to detect older kernels, as they will just ignore IFLA_IF_NETNSID and query in the current name space. This patch implemetns IFLA_IF_NETNSID only for get and dump. For set operations, this can be extended later. Signed-off-by: Jiri Benc --- include/uapi/linux/if_link.h | 1 + net/core/rtnetlink.c | 103 +++++++++++++++++++++++++++++++++++-------- 2 files changed, 86 insertions(+), 18 deletions(-) diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h index b037e0ab1975..ba705219df40 100644 --- a/include/uapi/linux/if_link.h +++ b/include/uapi/linux/if_link.h @@ -159,6 +159,7 @@ enum { IFLA_XDP, IFLA_EVENT, IFLA_NEW_NETNSID, + IFLA_IF_NETNSID, __IFLA_MAX }; diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index de24d394c69e..8a8c51937edf 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -921,7 +921,8 @@ static noinline size_t if_nlmsg_size(const struct net_device *dev, + nla_total_size(4) /* IFLA_EVENT */ + nla_total_size(4) /* IFLA_NEW_NETNSID */ + nla_total_size(1); /* IFLA_PROTO_DOWN */ - + + nla_total_size(4) /* IFLA_IF_NETNSID */ + + 0; } static int rtnl_vf_ports_fill(struct sk_buff *skb, struct net_device *dev) @@ -1370,13 +1371,14 @@ static noinline_for_stack int nla_put_ifalias(struct sk_buff *skb, } static int rtnl_fill_link_netnsid(struct sk_buff *skb, - const struct net_device *dev) + const struct net_device *dev, + struct net *src_net) { if (dev->rtnl_link_ops && dev->rtnl_link_ops->get_link_net) { struct net *link_net = dev->rtnl_link_ops->get_link_net(dev); if (!net_eq(dev_net(dev), link_net)) { - int id = peernet2id_alloc(dev_net(dev), link_net); + int id = peernet2id_alloc(src_net, link_net); if (nla_put_s32(skb, IFLA_LINK_NETNSID, id)) return -EMSGSIZE; @@ -1427,10 +1429,11 @@ static int rtnl_fill_link_af(struct sk_buff *skb, return 0; } -static int rtnl_fill_ifinfo(struct sk_buff *skb, struct net_device *dev, +static int rtnl_fill_ifinfo(struct sk_buff *skb, + struct net_device *dev, struct net *src_net, int type, u32 pid, u32 seq, u32 change, unsigned int flags, u32 ext_filter_mask, - u32 event, int *new_nsid) + u32 event, int *new_nsid, int tgt_netnsid) { struct ifinfomsg *ifm; struct nlmsghdr *nlh; @@ -1448,6 +1451,9 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb, struct net_device *dev, ifm->ifi_flags = dev_get_flags(dev); ifm->ifi_change = change; + if (tgt_netnsid >= 0 && nla_put_s32(skb, IFLA_IF_NETNSID, tgt_netnsid)) + goto nla_put_failure; + if (nla_put_string(skb, IFLA_IFNAME, dev->name) || nla_put_u32(skb, IFLA_TXQLEN, dev->tx_queue_len) || nla_put_u8(skb, IFLA_OPERSTATE, @@ -1513,7 +1519,7 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb, struct net_device *dev, goto nla_put_failure; } - if (rtnl_fill_link_netnsid(skb, dev)) + if (rtnl_fill_link_netnsid(skb, dev, src_net)) goto nla_put_failure; if (new_nsid && @@ -1571,6 +1577,7 @@ static const struct nla_policy ifla_policy[IFLA_MAX+1] = { [IFLA_XDP] = { .type = NLA_NESTED }, [IFLA_EVENT] = { .type = NLA_U32 }, [IFLA_GROUP] = { .type = NLA_U32 }, + [IFLA_IF_NETNSID] = { .type = NLA_S32 }, }; static const struct nla_policy ifla_info_policy[IFLA_INFO_MAX+1] = { @@ -1674,9 +1681,28 @@ static bool link_dump_filtered(struct net_device *dev, return false; } +static struct net *get_target_net(struct sk_buff *skb, int netnsid) +{ + struct net *net; + + net = get_net_ns_by_id(sock_net(skb->sk), netnsid); + if (!net) + return ERR_PTR(-EINVAL); + + /* For now, the caller is required to have CAP_NET_ADMIN in + * the user namespace owning the target net ns. + */ + if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN)) { + put_net(net); + return ERR_PTR(-EACCES); + } + return net; +} + static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb) { struct net *net = sock_net(skb->sk); + struct net *tgt_net = net; int h, s_h; int idx = 0, s_idx; struct net_device *dev; @@ -1686,6 +1712,7 @@ static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb) const struct rtnl_link_ops *kind_ops = NULL; unsigned int flags = NLM_F_MULTI; int master_idx = 0; + int netnsid = -1; int err; int hdrlen; @@ -1704,6 +1731,15 @@ static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb) if (nlmsg_parse(cb->nlh, hdrlen, tb, IFLA_MAX, ifla_policy, NULL) >= 0) { + if (tb[IFLA_IF_NETNSID]) { + netnsid = nla_get_s32(tb[IFLA_IF_NETNSID]); + tgt_net = get_target_net(skb, netnsid); + if (IS_ERR(tgt_net)) { + tgt_net = net; + netnsid = -1; + } + } + if (tb[IFLA_EXT_MASK]) ext_filter_mask = nla_get_u32(tb[IFLA_EXT_MASK]); @@ -1719,17 +1755,19 @@ static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb) for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) { idx = 0; - head = &net->dev_index_head[h]; + head = &tgt_net->dev_index_head[h]; hlist_for_each_entry(dev, head, index_hlist) { if (link_dump_filtered(dev, master_idx, kind_ops)) goto cont; if (idx < s_idx) goto cont; - err = rtnl_fill_ifinfo(skb, dev, RTM_NEWLINK, + err = rtnl_fill_ifinfo(skb, dev, net, + RTM_NEWLINK, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, 0, flags, - ext_filter_mask, 0, NULL); + ext_filter_mask, 0, NULL, + netnsid); if (err < 0) { if (likely(skb->len)) @@ -1748,6 +1786,8 @@ static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb) cb->args[0] = h; cb->seq = net->dev_base_seq; nl_dump_check_consistent(cb, nlmsg_hdr(skb)); + if (netnsid >= 0) + put_net(tgt_net); return err; } @@ -2360,6 +2400,9 @@ static int rtnl_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, if (err < 0) goto errout; + if (tb[IFLA_IF_NETNSID]) + return -EOPNOTSUPP; + if (tb[IFLA_IFNAME]) nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ); else @@ -2454,6 +2497,9 @@ static int rtnl_dellink(struct sk_buff *skb, struct nlmsghdr *nlh, if (err < 0) return err; + if (tb[IFLA_IF_NETNSID]) + return -EOPNOTSUPP; + if (tb[IFLA_IFNAME]) nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ); @@ -2585,6 +2631,9 @@ static int rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh, if (err < 0) return err; + if (tb[IFLA_IF_NETNSID]) + return -EOPNOTSUPP; + if (tb[IFLA_IFNAME]) nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ); else @@ -2818,11 +2867,13 @@ static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr *nlh, struct netlink_ext_ack *extack) { struct net *net = sock_net(skb->sk); + struct net *tgt_net = net; struct ifinfomsg *ifm; char ifname[IFNAMSIZ]; struct nlattr *tb[IFLA_MAX+1]; struct net_device *dev = NULL; struct sk_buff *nskb; + int netnsid = -1; int err; u32 ext_filter_mask = 0; @@ -2830,35 +2881,50 @@ static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr *nlh, if (err < 0) return err; + if (tb[IFLA_IF_NETNSID]) { + netnsid = nla_get_s32(tb[IFLA_IF_NETNSID]); + tgt_net = get_target_net(skb, netnsid); + if (IS_ERR(tgt_net)) + return PTR_ERR(tgt_net); + } + if (tb[IFLA_IFNAME]) nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ); if (tb[IFLA_EXT_MASK]) ext_filter_mask = nla_get_u32(tb[IFLA_EXT_MASK]); + err = -EINVAL; ifm = nlmsg_data(nlh); if (ifm->ifi_index > 0) - dev = __dev_get_by_index(net, ifm->ifi_index); + dev = __dev_get_by_index(tgt_net, ifm->ifi_index); else if (tb[IFLA_IFNAME]) - dev = __dev_get_by_name(net, ifname); + dev = __dev_get_by_name(tgt_net, ifname); else - return -EINVAL; + goto out; + err = -ENODEV; if (dev == NULL) - return -ENODEV; + goto out; + err = -ENOBUFS; nskb = nlmsg_new(if_nlmsg_size(dev, ext_filter_mask), GFP_KERNEL); if (nskb == NULL) - return -ENOBUFS; + goto out; - err = rtnl_fill_ifinfo(nskb, dev, RTM_NEWLINK, NETLINK_CB(skb).portid, - nlh->nlmsg_seq, 0, 0, ext_filter_mask, 0, NULL); + err = rtnl_fill_ifinfo(nskb, dev, net, + RTM_NEWLINK, NETLINK_CB(skb).portid, + nlh->nlmsg_seq, 0, 0, ext_filter_mask, + 0, NULL, netnsid); if (err < 0) { /* -EMSGSIZE implies BUG in if_nlmsg_size */ WARN_ON(err == -EMSGSIZE); kfree_skb(nskb); } else err = rtnl_unicast(nskb, net, NETLINK_CB(skb).portid); +out: + if (netnsid >= 0) + put_net(tgt_net); return err; } @@ -2948,8 +3014,9 @@ struct sk_buff *rtmsg_ifinfo_build_skb(int type, struct net_device *dev, if (skb == NULL) goto errout; - err = rtnl_fill_ifinfo(skb, dev, type, 0, 0, change, 0, 0, event, - new_nsid); + err = rtnl_fill_ifinfo(skb, dev, dev_net(dev), + type, 0, 0, change, 0, 0, event, + new_nsid, -1); if (err < 0) { /* -EMSGSIZE implies BUG in if_nlmsg_size() */ WARN_ON(err == -EMSGSIZE);