From d8a5ec672768c3cf4d51d7a63fc071520afa1617 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Wed, 12 Sep 2007 13:57:04 +0200 Subject: [PATCH] [NET]: netlink support for moving devices between network namespaces. The simplest thing to implement is moving network devices between namespaces. However with the same attribute IFLA_NET_NS_PID we can easily implement creating devices in the destination network namespace as well. However that is a little bit trickier so this patch sticks to what is simple and easy. A pid is used to identify a process that happens to be a member of the network namespace we want to move the network device to. Signed-off-by: Eric W. Biederman Signed-off-by: David S. Miller --- include/linux/if_link.h | 1 + net/core/rtnetlink.c | 35 +++++++++++++++++++++++++++++++++++ 2 files changed, 36 insertions(+) diff --git a/include/linux/if_link.h b/include/linux/if_link.h index 422084d18ce1..84c3492ae5cb 100644 --- a/include/linux/if_link.h +++ b/include/linux/if_link.h @@ -78,6 +78,7 @@ enum IFLA_LINKMODE, IFLA_LINKINFO, #define IFLA_LINKINFO IFLA_LINKINFO + IFLA_NET_NS_PID, __IFLA_MAX }; diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 44f91bb1ae8d..1b9c32d79917 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -35,6 +35,7 @@ #include #include #include +#include #include #include @@ -727,6 +728,7 @@ const struct nla_policy ifla_policy[IFLA_MAX+1] = { [IFLA_WEIGHT] = { .type = NLA_U32 }, [IFLA_OPERSTATE] = { .type = NLA_U8 }, [IFLA_LINKMODE] = { .type = NLA_U8 }, + [IFLA_NET_NS_PID] = { .type = NLA_U32 }, }; static const struct nla_policy ifla_info_policy[IFLA_INFO_MAX+1] = { @@ -734,12 +736,45 @@ static const struct nla_policy ifla_info_policy[IFLA_INFO_MAX+1] = { [IFLA_INFO_DATA] = { .type = NLA_NESTED }, }; +static struct net *get_net_ns_by_pid(pid_t pid) +{ + struct task_struct *tsk; + struct net *net; + + /* Lookup the network namespace */ + net = ERR_PTR(-ESRCH); + rcu_read_lock(); + tsk = find_task_by_pid(pid); + if (tsk) { + task_lock(tsk); + if (tsk->nsproxy) + net = get_net(tsk->nsproxy->net_ns); + task_unlock(tsk); + } + rcu_read_unlock(); + return net; +} + static int do_setlink(struct net_device *dev, struct ifinfomsg *ifm, struct nlattr **tb, char *ifname, int modified) { int send_addr_notify = 0; int err; + if (tb[IFLA_NET_NS_PID]) { + struct net *net; + net = get_net_ns_by_pid(nla_get_u32(tb[IFLA_NET_NS_PID])); + if (IS_ERR(net)) { + err = PTR_ERR(net); + goto errout; + } + err = dev_change_net_namespace(dev, net, ifname); + put_net(net); + if (err) + goto errout; + modified = 1; + } + if (tb[IFLA_MAP]) { struct rtnl_link_ifmap *u_map; struct ifmap k_map; -- 2.20.1