[Devel] [PATCH RFC 9/31] net: Implement the per network namespace sysctl infrastructure
Eric W. Biederman
ebiederm at xmission.com
Thu Jan 25 11:00:11 PST 2007
From: Eric W. Biederman <ebiederm at xmission.com> - unquoted
The user interface is: register_net_sysctl_table and
unregister_net_sysctl_table. Very much like the current
interface except there is an network namespace parameter.
This this any sysctl in the net_root_table and it's
subdirectories are registered with register_net_sysctl
shows up only to tasks in the same network namespace.
All other sysctls continue to be globally visible.
Signed-off-by: Eric W. Biederman <ebiederm at xmission.com>
---
include/linux/sysctl.h | 7 ++++
include/net/sock.h | 1 +
kernel/sysctl.c | 71 ++++++++++++++++++++++++++++++++++++++++++-
net/core/sysctl_net_core.c | 5 +++
net/sysctl_net.c | 20 ++++++++++++
5 files changed, 102 insertions(+), 2 deletions(-)
diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 8eba2d2..286e723 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -1044,6 +1044,13 @@ struct ctl_table_header * register_sysctl_table(ctl_table * table);
void unregister_sysctl_table(struct ctl_table_header * table);
+#ifdef CONFIG_NET
+#include <linux/net_namespace_type.h>
+extern struct ctl_table_header *register_net_sysctl_table(net_t net, struct ctl_table *table);
+extern void unregister_net_sysctl_table(struct ctl_table_header *header);
+DECLARE_PER_NET(struct ctl_table, net_root_table[]);
+#endif
+
#else /* __KERNEL__ */
#endif /* __KERNEL__ */
diff --git a/include/net/sock.h b/include/net/sock.h
index 5bf6bb5..01a2781 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1414,6 +1414,7 @@ extern void sk_init(void);
#ifdef CONFIG_SYSCTL
extern struct ctl_table core_table[];
+DECLARE_PER_NET(struct ctl_table, multi_core_table[]);
#endif
extern int sysctl_optmem_max;
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 7da313e..ae6a424 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -45,6 +45,7 @@
#include <linux/syscalls.h>
#include <linux/nfs_fs.h>
#include <linux/acpi.h>
+#include <net/net_namespace.h>
#include <asm/uaccess.h>
#include <asm/processor.h>
@@ -135,6 +136,10 @@ static int proc_do_cad_pid(ctl_table *table, int write, struct file *filp,
void __user *buffer, size_t *lenp, loff_t *ppos);
#endif
+#ifdef CONFIG_NET
+static DEFINE_PER_NET(struct ctl_table_header, net_table_header);
+#endif
+
static ctl_table root_table[];
static struct ctl_table_header root_table_header =
{ root_table, LIST_HEAD_INIT(root_table_header.ctl_entry) };
@@ -1059,6 +1064,7 @@ struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
{
struct ctl_table_header *head;
struct list_head *tmp;
+ net_t net = current->nsproxy->net_ns;
spin_lock(&sysctl_lock);
if (prev) {
tmp = &prev->ctl_entry;
@@ -1076,6 +1082,10 @@ struct ctl_table_header *sysctl_head_next(struct ctl_table_header *prev)
next:
tmp = tmp->next;
if (tmp == &root_table_header.ctl_entry)
+#ifdef CONFIG_NET
+ tmp = &per_net(net_table_header, net).ctl_entry;
+ else if (tmp == &per_net(net_table_header, net).ctl_entry)
+#endif
break;
}
spin_unlock(&sysctl_lock);
@@ -1290,7 +1300,8 @@ int do_sysctl_strategy (ctl_table *table,
* This routine returns %NULL on a failure to register, and a pointer
* to the table header on success.
*/
-struct ctl_table_header *register_sysctl_table(ctl_table * table)
+static struct ctl_table_header *__register_sysctl_table(
+ struct ctl_table_header *root, ctl_table * table)
{
struct ctl_table_header *tmp;
tmp = kmalloc(sizeof(struct ctl_table_header), GFP_KERNEL);
@@ -1301,11 +1312,16 @@ struct ctl_table_header *register_sysctl_table(ctl_table * table)
tmp->used = 0;
tmp->unregistering = NULL;
spin_lock(&sysctl_lock);
- list_add_tail(&tmp->ctl_entry, &root_table_header.ctl_entry);
+ list_add_tail(&tmp->ctl_entry, &root->ctl_entry);
spin_unlock(&sysctl_lock);
return tmp;
}
+struct ctl_table_header *register_sysctl_table(ctl_table *table)
+{
+ return __register_sysctl_table(&root_table_header, table);
+}
+
/**
* unregister_sysctl_table - unregister a sysctl table hierarchy
* @header: the header returned from register_sysctl_table
@@ -1322,6 +1338,57 @@ void unregister_sysctl_table(struct ctl_table_header * header)
kfree(header);
}
+#ifdef CONFIG_NET
+
+static void *fixup_per_net_addr(net_t net, void *addr)
+{
+ char *ptr = addr;
+ if ((ptr >= __per_net_start) && (ptr < __per_net_end))
+ ptr += __per_net_offset(net);
+ return ptr;
+}
+
+static void sysctl_net_table_fixup(net_t net, struct ctl_table *table)
+{
+ for (; table->ctl_name || table->procname; table++) {
+ table->child = fixup_per_net_addr(net, table->child);
+ table->data = fixup_per_net_addr(net, table->data);
+ table->extra1 = fixup_per_net_addr(net, table->extra1);
+ table->extra2 = fixup_per_net_addr(net, table->extra2);
+
+ /* Whee recursive functions on the kernel stack */
+ if (table->child)
+ sysctl_net_table_fixup(net, table->child);
+ }
+}
+
+static void sysctl_net_init(net_t net)
+{
+ struct ctl_table *table = per_net(net_root_table, net);
+
+ sysctl_net_table_fixup(net, table);
+ per_net(net_table_header, net).ctl_table = table;
+
+ INIT_LIST_HEAD(&per_net(net_table_header, net).ctl_entry);
+}
+
+struct ctl_table_header *register_net_sysctl_table(net_t net, ctl_table *table)
+{
+ if (!per_net(net_table_header, net).ctl_table)
+ sysctl_net_init(net);
+ sysctl_net_table_fixup(net, table);
+ return __register_sysctl_table(&per_net(net_table_header, net), table);
+}
+EXPORT_SYMBOL_GPL(register_net_sysctl_table);
+
+void unregister_net_sysctl_table(struct ctl_table_header *header)
+{
+ return unregister_sysctl_table(header);
+}
+EXPORT_SYMBOL_GPL(unregister_net_sysctl_table);
+#endif
+
+
#else /* !CONFIG_SYSCTL */
struct ctl_table_header * register_sysctl_table(ctl_table * table,
int insert_at_head)
diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c
index 176ad08..76f7a29 100644
--- a/net/core/sysctl_net_core.c
+++ b/net/core/sysctl_net_core.c
@@ -125,3 +125,8 @@ ctl_table core_table[] = {
},
{ .ctl_name = 0 }
};
+
+DEFINE_PER_NET(struct ctl_table, multi_core_table[]) = {
+ /* Stub for holding per network namespace sysctls */
+ {}
+};
diff --git a/net/sysctl_net.c b/net/sysctl_net.c
index cd4eafb..359c163 100644
--- a/net/sysctl_net.c
+++ b/net/sysctl_net.c
@@ -54,3 +54,23 @@ struct ctl_table net_table[] = {
#endif
{ 0 },
};
+
+DEFINE_PER_NET(struct ctl_table, multi_net_table[]) = {
+ {
+ .ctl_name = NET_CORE,
+ .procname = "core",
+ .mode = 0555,
+ .child = __per_net_base(multi_core_table),
+ },
+ {},
+};
+
+DEFINE_PER_NET(struct ctl_table, net_root_table[]) = {
+ {
+ .ctl_name = CTL_NET,
+ .procname = "net",
+ .mode = 0555,
+ .child = __per_net_base(multi_net_table),
+ },
+ {},
+};
--
1.4.4.1.g278f
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