// SPDX-License-Identifier: GPL-2.0/* Multipath TCP * * Copyright (c) 2019, Tessares SA. */ #include <linux/sysctl.h> #include <net/net_namespace.h>#include <net/netns/generic.h> #include "protocol.h" #define MPTCP_SYSCTL_PATH "net/mptcp" static int mptcp_pernet_id;struct mptcp_pernet {	struct ctl_table_header *ctl_table_hdr; 	int mptcp_enabled;	unsigned int add_addr_timeout;}; static struct mptcp_pernet *mptcp_get_pernet(struct net *net){	return net_generic(net, mptcp_pernet_id);} int mptcp_is_enabled(struct net *net){	return mptcp_get_pernet(net)->mptcp_enabled;} unsigned int mptcp_get_add_addr_timeout(struct net *net){	return mptcp_get_pernet(net)->add_addr_timeout;} static struct ctl_table mptcp_sysctl_table[] = {	{		.procname = "enabled",		.maxlen = sizeof(int),		.mode = 0644,		/* users with CAP_NET_ADMIN or root (not and) can change this		 * value, same as other sysctl or the 'net' tree.		 */		.proc_handler = proc_dointvec,	},	{		.procname = "add_addr_timeout",		.maxlen = sizeof(unsigned int),		.mode = 0644,		.proc_handler = proc_dointvec_jiffies,	},	{}}; static void mptcp_pernet_set_defaults(struct mptcp_pernet *pernet){	pernet->mptcp_enabled = 1;	pernet->add_addr_timeout = TCP_RTO_MAX;} static int mptcp_pernet_new_table(struct net *net, struct mptcp_pernet *pernet){	struct ctl_table_header *hdr;	struct ctl_table *table; 	table = mptcp_sysctl_table;	if (!net_eq(net, &init_net)) {		table = kmemdup(table, sizeof(mptcp_sysctl_table), GFP_KERNEL);		if (!table)			goto err_alloc;	} 	table[0].data = &pernet->mptcp_enabled;	table[1].data = &pernet->add_addr_timeout; 	hdr = register_net_sysctl(net, MPTCP_SYSCTL_PATH, table);	if (!hdr)		goto err_reg; 	pernet->ctl_table_hdr = hdr; 	return 0; err_reg:	if (!net_eq(net, &init_net))		kfree(table);err_alloc:	return -ENOMEM;} static void mptcp_pernet_del_table(struct mptcp_pernet *pernet){	struct ctl_table *table = pernet->ctl_table_hdr->ctl_table_arg; 	unregister_net_sysctl_table(pernet->ctl_table_hdr); 	kfree(table);} static int __net_init mptcp_net_init(struct net *net){	struct mptcp_pernet *pernet = mptcp_get_pernet(net); 	mptcp_pernet_set_defaults(pernet); 	return mptcp_pernet_new_table(net, pernet);} /* Note: the callback will only be called per extra netns */static void __net_exit mptcp_net_exit(struct net *net){	struct mptcp_pernet *pernet = mptcp_get_pernet(net); 	mptcp_pernet_del_table(pernet);} static struct pernet_operations mptcp_pernet_ops = {	.init = mptcp_net_init,	.exit = mptcp_net_exit,	.id = &mptcp_pernet_id,	.size = sizeof(struct mptcp_pernet),}; void __init mptcp_init(void){	mptcp_join_cookie_init();	mptcp_proto_init(); 	if (register_pernet_subsys(&mptcp_pernet_ops) < 0)		panic("Failed to register MPTCP pernet subsystem.\n");} #if IS_ENABLED(CONFIG_MPTCP_IPV6)int __init mptcpv6_init(void){	int err; 	err = mptcp_proto_v6_init(); 	return err;}#endif