[Devel] [patch 20/20] [Network namespace] For debug purpose, used to unshare the network namespace.

[dlezcano at fr.ibm.com]

Signed-off-by: Daniel Lezcano <dlezcano at fr.ibm.com>

---

 fs/debugfs/net_ns.c |  131 ++++++++++++++++++++++++++++++++++++++++++++++++++--
 1 files changed, 127 insertions(+), 4 deletions(-)

Index: 2.6.19-rc6-mm2/fs/debugfs/net_ns.c
===================================================================
--- 2.6.19-rc6-mm2.orig/fs/debugfs/net_ns.c
+++ 2.6.19-rc6-mm2/fs/debugfs/net_ns.c
@@ -15,8 +15,10 @@
 #include <linux/debugfs.h>
 #include <linux/sched.h>
 #include <linux/netdevice.h>
+#include <linux/inetdevice.h>
 #include <linux/syscalls.h>
 #include <linux/net_namespace.h>
+#include <linux/rtnetlink.h>
 
 static struct dentry *net_ns_dentry;
 static struct dentry *net_ns_dentry_dev;
@@ -52,8 +54,6 @@ static ssize_t net_ns_start_read_file(st
 	return 0;
 }
 
-int net_ns_start(void);
-
 static ssize_t net_ns_start_write_file(struct file *file,
 				       const char __user *user_buf,
 				       size_t count, loff_t *ppos)
@@ -63,6 +63,8 @@ static ssize_t net_ns_start_write_file(s
 	const char __user *p;
 	char c;
 	unsigned long flags;
+	struct net_namespace *net, *new_net;
+ 	struct nsproxy *new_nsproxy = NULL, *old_nsproxy = NULL;
 
 	if (current_net_ns != &init_net_ns)
 		return -EBUSY;
@@ -87,10 +89,37 @@ static ssize_t net_ns_start_write_file(s
 		return -EINVAL;
 
 	flags = (c=='2'?NS_NET2:NS_NET3);
-	err = sys_unshare_ns(flags);
+
+	err = unshare_net_ns(flags, &new_net);
 	if (err)
 		return err;
 
+	old_nsproxy = current->nsproxy;
+	new_nsproxy = dup_namespaces(old_nsproxy);
+
+	if (!new_nsproxy) {
+		put_net_ns(new_net);
+		task_unlock(current);
+		return -ENOMEM;
+	}
+
+	task_lock(current);
+
+	if (new_nsproxy) {
+		current->nsproxy = new_nsproxy;
+		new_nsproxy = old_nsproxy;
+	}
+
+	new_net->ns = current->nsproxy;
+	net = current->nsproxy->net_ns;
+	current->nsproxy->net_ns = new_net;
+	new_net = net;
+
+	task_unlock(current);
+
+	put_nsproxy(new_nsproxy);
+	put_net_ns(new_net);
+
 	return count;
 }
 
@@ -152,8 +181,102 @@ static ssize_t net_ns_info_write_file(st
 				      const char __user *user_buf,
 				      size_t count, loff_t *ppos)
 {
+	struct net_namespace *net_ns = current_net_ns;
+	struct net_device *dev;
+	struct in_device *in_dev;
+	struct in_ifaddr **ifap = NULL;
+	struct in_ifaddr *ifa = NULL;
+	char *colon;
+	int err;
+
+	char buff[1024];
+	char *eth, *addr, *s;
+	__be32 address = 0;
+	__be32 p;
+
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
+	if (net_ns->level != NET_NS_LEVEL3)
+		return -EPERM;
+
+	if (count > sizeof(buff))
+		return -EINVAL;
+
+	if (copy_from_user(buff, user_buf, count))
+		return -EFAULT;
+
+	buff[count] = '\0';
+
+        eth = buff;
+        s = strchr(eth, ' ');
+        if (!s)
+                return -EINVAL;
+        *s = 0;
+
+        addr = s + 1;
+        s = strchr(addr, '.');
+        if (!s)
+                return -EINVAL;
+        *s = 0;
+        p = simple_strtoul(addr, NULL, 0);
+        ((char *)&address)[3] = p;
+        addr = s + 1;
+
+        s = strchr(addr, '.');
+        if (!s)
+                return -EINVAL;
+        *s = 0;
+        p = simple_strtoul(addr, NULL, 0);
+        ((char *)&address)[2] = p;
+        addr = s + 1;
+
+        s = strchr(addr, '.');
+        if (!s)
+                return -EINVAL;
+        *s = 0;
+        p = simple_strtoul(addr, NULL, 0);
+        ((char *)&address)[1] = p;
+        addr = s + 1;
+
+        p = simple_strtoul(addr, NULL, 0);
+        ((char *)&address)[0]  = p;
+
+	colon = strchr(eth, ':');
+	if (colon)
+		*colon = 0;
+
+        address = htonl(address);
+
+	rtnl_lock();
+
+	err = -ENODEV;
+	dev = __dev_get_by_name(eth);
+	if (!dev)
+		goto out;
+
+	if (colon)
+		*colon = ':';
+
+	err = -EADDRNOTAVAIL;
+	in_dev = __in_dev_get_rtnl(dev);
+	if (!in_dev)
+		goto out;
+
+	for (ifap = &in_dev->ifa_list; (ifa = *ifap) != NULL;
+	     ifap = &ifa->ifa_next)
+		if (!strcmp(eth, ifa->ifa_label) &&
+		    address == ifa->ifa_local)
+			break;
+	if (!ifa)
+		goto out;
+
+	ifa->ifa_net_ns = net_ns;
 
-	return -EPERM;
+	err = count;
+out:
+	rtnl_unlock();
+	return err;
 }
 
 

-- 
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