[PATCH 10/12] L2 network namespace (v3): playing with pass-through
device
Dmitry Mishin
dim at openvz.org
Wed Jan 17 08:15:15 PST 2007
Temporary code to debug and play with pass-through device.
Create device pair by
modprobe veth
echo 'add veth1 0:1:2:3:4:1 eth0 0:1:2:3:4:2' >/proc/net/veth_ctl
and your shell will appear into a new namespace with `eth0' device.
Configure device in this namespace
ip l s eth0 up
ip a a 1.2.3.4/24 dev eth0
and in the root namespace
ip l s veth1 up
ip a a 1.2.3.1/24 dev veth1
to establish a communication channel between root namespace and the newly
created one.
Code is done by Andrey Savochkin and ported by me over Cedric'c patchset
Signed-off-by: Dmitry Mishin <dim at openvz.org>
---
drivers/net/veth.c | 121 +++++++++++++++++++++++++++++++++++++++++++++++
fs/proc/array.c | 8 +++
kernel/fork.c | 1
kernel/nsproxy.c | 1
net/core/net_namespace.c | 3 +
5 files changed, 134 insertions(+)
--- linux-2.6.20-rc4-mm1.net_ns.orig/drivers/net/veth.c
+++ linux-2.6.20-rc4-mm1.net_ns/drivers/net/veth.c
@@ -12,6 +12,7 @@
#include <linux/etherdevice.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
+#include <linux/syscalls.h>
#include <net/dst.h>
#include <net/xfrm.h>
@@ -245,6 +246,123 @@ void veth_entry_del_all(void)
/* ------------------------------------------------------------------- *
*
+ * Temporary interface to create veth devices
+ *
+ * ------------------------------------------------------------------- */
+
+#ifdef CONFIG_PROC_FS
+
+static int veth_debug_open(struct inode *inode, struct file *file)
+{
+ return 0;
+}
+
+static char *parse_addr(char *s, char *addr)
+{
+ int i, v;
+
+ for (i = 0; i < ETH_ALEN; i++) {
+ if (!isxdigit(*s))
+ return NULL;
+ *addr = 0;
+ v = isdigit(*s) ? *s - '0' : toupper(*s) - 'A' + 10;
+ s++;
+ if (isxdigit(*s)) {
+ *addr += v << 16;
+ v = isdigit(*s) ? *s - '0' : toupper(*s) - 'A' + 10;
+ s++;
+ }
+ *addr++ += v;
+ if (i < ETH_ALEN - 1 && ispunct(*s))
+ s++;
+ }
+ return s;
+}
+
+static ssize_t veth_debug_write(struct file *file, const char __user *user_buf,
+ size_t size, loff_t *ppos)
+{
+ char buf[128], *s, *parent_name, *child_name;
+ char parent_addr[ETH_ALEN], child_addr[ETH_ALEN];
+ struct net_namespace *parent_ns, *child_ns;
+ int err;
+
+ s = buf;
+ err = -EINVAL;
+ if (size >= sizeof(buf))
+ goto out;
+ err = -EFAULT;
+ if (copy_from_user(buf, user_buf, size))
+ goto out;
+ buf[size] = 0;
+
+ err = -EBADRQC;
+ if (!strncmp(buf, "add ", 4)) {
+ parent_name = buf + 4;
+ if ((s = strchr(parent_name, ' ')) == NULL)
+ goto out;
+ *s = 0;
+ if ((s = parse_addr(s + 1, parent_addr)) == NULL)
+ goto out;
+ if (!*s)
+ goto out;
+ child_name = s + 1;
+ if ((s = strchr(child_name, ' ')) == NULL)
+ goto out;
+ *s = 0;
+ if ((s = parse_addr(s + 1, child_addr)) == NULL)
+ goto out;
+
+ get_net_ns(current_net_ns);
+ parent_ns = current_net_ns;
+ if (*s == ' ') {
+ unsigned int id;
+ id = simple_strtoul(s + 1, &s, 0);
+ err = sys_bind_ns(id, NS_ALL);
+ } else
+ err = sys_unshare(CLONE_NEWNET2);
+ if (err)
+ goto out;
+ /* after bind_ns() or unshare_ns() namespace is changed */
+ get_net_ns(current_net_ns);
+ child_ns = current_net_ns;
+ err = veth_entry_add(parent_name, parent_addr, parent_ns,
+ child_name, child_addr, child_ns);
+ if (err) {
+ put_net_ns(child_ns);
+ put_net_ns(parent_ns);
+ } else
+ err = size;
+ }
+out:
+ return err;
+}
+
+static struct file_operations veth_debug_ops = {
+ .open = &veth_debug_open,
+ .write = &veth_debug_write,
+};
+
+static int veth_debug_create(void)
+{
+ proc_net_fops_create("veth_ctl", 0200, &veth_debug_ops);
+ return 0;
+}
+
+static void veth_debug_remove(void)
+{
+ proc_net_remove("veth_ctl");
+}
+
+#else
+
+static int veth_debug_create(void) { return -1; }
+static void veth_debug_remove(void) { }
+
+#endif
+
+/* ------------------------------------------------------------------- *
+ *
* Information in proc
*
* ------------------------------------------------------------------- */
@@ -304,12 +422,15 @@ static inline void veth_proc_remove(void
int __init veth_init(void)
{
+ if (veth_debug_create())
+ return -EINVAL;
veth_proc_create();
return 0;
}
void __exit veth_exit(void)
{
+ veth_debug_remove();
veth_proc_remove();
veth_entry_del_all();
}
--- linux-2.6.20-rc4-mm1.net_ns.orig/fs/proc/array.c
+++ linux-2.6.20-rc4-mm1.net_ns/fs/proc/array.c
@@ -72,6 +72,7 @@
#include <linux/highmem.h>
#include <linux/file.h>
#include <linux/times.h>
+#include <linux/net_namespace.h>
#include <linux/cpuset.h>
#include <linux/rcupdate.h>
#include <linux/delayacct.h>
@@ -198,6 +199,13 @@ static inline char * task_state(struct t
put_group_info(group_info);
buffer += sprintf(buffer, "\n");
+
+#ifdef CONFIG_NET_NS
+ if (p == current)
+ buffer += sprintf(buffer, "NetContext: %p\n",
+ p->nsproxy->net_ns);
+#endif
+
return buffer;
}
--- linux-2.6.20-rc4-mm1.net_ns.orig/kernel/fork.c
+++ linux-2.6.20-rc4-mm1.net_ns/kernel/fork.c
@@ -1770,3 +1770,4 @@ bad_unshare_cleanup_thread:
bad_unshare_out:
return err;
}
+EXPORT_SYMBOL_GPL(sys_unshare);
--- linux-2.6.20-rc4-mm1.net_ns.orig/kernel/nsproxy.c
+++ linux-2.6.20-rc4-mm1.net_ns/kernel/nsproxy.c
@@ -426,6 +426,7 @@ unlock:
put_nsproxy(ns);
return ret;
}
+EXPORT_SYMBOL(sys_bind_ns);
static int __init nshash_init(void)
{
--- linux-2.6.20-rc4-mm1.net_ns.orig/net/core/net_namespace.c
+++ linux-2.6.20-rc4-mm1.net_ns/net/core/net_namespace.c
@@ -56,6 +56,8 @@ static struct net_namespace *clone_net_n
if (loopback_init())
goto out_loopback;
pop_net_ns(old_ns);
+ printk(KERN_DEBUG "NET_NS: created new netcontext %p for %s "
+ "(pid=%d)\n", ns, current->comm, current->tgid);
return ns;
out_loopback:
@@ -109,6 +111,7 @@ void free_net_ns(struct kref *kref)
return;
}
ip_fib_struct_cleanup(ns);
+ printk(KERN_DEBUG "NET_NS: net namespace %p destroyed\n", ns);
kfree(ns);
}
EXPORT_SYMBOL(free_net_ns);
More information about the Containers
mailing list