/* -*- linux-c -*- * sysctl_net.c: sysctl interface to net subsystem. * * Begun April 1, 1996, Mike Shaver. * Added /proc/sys/net directories for each protocol family. [MS] * * Revision 1.2  1996/05/08  20:24:40  shaver * Added bits for NET_BRIDGE and the NET_IPV4_ARP stuff and * NET_IPV4_IP_FORWARD. * * */ #include <linux/mm.h>#include <linux/export.h>#include <linux/sysctl.h>#include <linux/nsproxy.h> #include <net/sock.h> #ifdef CONFIG_INET#include <net/ip.h>#endif #ifdef CONFIG_NET#include <linux/if_ether.h>#endif #ifdef CONFIG_TR#include <linux/if_tr.h>#endif static struct ctl_table_set *net_ctl_header_lookup(struct ctl_table_root *root, struct nsproxy *namespaces){	return &namespaces->net_ns->sysctls;} static int is_seen(struct ctl_table_set *set){	return &current->nsproxy->net_ns->sysctls == set;} /* Return standard mode bits for table entry. */static int net_ctl_permissions(struct ctl_table_root *root,			       struct nsproxy *nsproxy,			       struct ctl_table *table){	/* Allow network administrator to have same access as root. */	if (capable(CAP_NET_ADMIN)) {		int mode = (table->mode >> 6) & 7;		return (mode << 6) | (mode << 3) | mode;	}	return table->mode;} static struct ctl_table_root net_sysctl_root = {	.lookup = net_ctl_header_lookup,	.permissions = net_ctl_permissions,}; static int net_ctl_ro_header_perms(struct ctl_table_root *root,		struct nsproxy *namespaces, struct ctl_table *table){	if (net_eq(namespaces->net_ns, &init_net))		return table->mode;	else		return table->mode & ~0222;} static struct ctl_table_root net_sysctl_ro_root = {	.permissions = net_ctl_ro_header_perms,}; static int __net_init sysctl_net_init(struct net *net){	setup_sysctl_set(&net->sysctls,			 &net_sysctl_ro_root.default_set,			 is_seen);	return 0;} static void __net_exit sysctl_net_exit(struct net *net){	WARN_ON(!list_empty(&net->sysctls.list));} static struct pernet_operations sysctl_pernet_ops = {	.init = sysctl_net_init,	.exit = sysctl_net_exit,}; static __init int sysctl_init(void){	int ret;	ret = register_pernet_subsys(&sysctl_pernet_ops);	if (ret)		goto out;	register_sysctl_root(&net_sysctl_root);	setup_sysctl_set(&net_sysctl_ro_root.default_set, NULL, NULL);	register_sysctl_root(&net_sysctl_ro_root);out:	return ret;}subsys_initcall(sysctl_init); struct ctl_table_header *register_net_sysctl_table(struct net *net,	const struct ctl_path *path, struct ctl_table *table){	struct nsproxy namespaces;	namespaces = *current->nsproxy;	namespaces.net_ns = net;	return __register_sysctl_paths(&net_sysctl_root,					&namespaces, path, table);}EXPORT_SYMBOL_GPL(register_net_sysctl_table); struct ctl_table_header *register_net_sysctl_rotable(const		struct ctl_path *path, struct ctl_table *table){	return __register_sysctl_paths(&net_sysctl_ro_root,			&init_nsproxy, path, table);}EXPORT_SYMBOL_GPL(register_net_sysctl_rotable); void unregister_net_sysctl_table(struct ctl_table_header *header){	unregister_sysctl_table(header);}EXPORT_SYMBOL_GPL(unregister_net_sysctl_table);