net/mptcp/ctrl.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Multipath TCP
   3  *
   4  * Copyright (c) 2019, Tessares SA.
   5  */
   6
   7 #include <linux/sysctl.h>
   8
   9 #include <net/net_namespace.h>
  10 #include <net/netns/generic.h>
  11
  12 #include "protocol.h"
  13
  14 #define MPTCP_SYSCTL_PATH "net/mptcp"
  15
  16 static int mptcp_pernet_id;
  17 struct mptcp_pernet {
  18         struct ctl_table_header *ctl_table_hdr;
  19
  20         int mptcp_enabled;
  21         unsigned int add_addr_timeout;
  22 };
  23
  24 static struct mptcp_pernet *mptcp_get_pernet(struct net *net)
  25 {
  26         return net_generic(net, mptcp_pernet_id);
  27 }
  28
  29 int mptcp_is_enabled(struct net *net)
  30 {
  31         return mptcp_get_pernet(net)->mptcp_enabled;
  32 }
  33
  34 unsigned int mptcp_get_add_addr_timeout(struct net *net)
  35 {
  36         return mptcp_get_pernet(net)->add_addr_timeout;
  37 }
  38
  39 static struct ctl_table mptcp_sysctl_table[] = {
  40         {
  41                 .procname = "enabled",
  42                 .maxlen = sizeof(int),
  43                 .mode = 0644,
  44                 /* users with CAP_NET_ADMIN or root (not and) can change this
  45                  * value, same as other sysctl or the 'net' tree.
  46                  */
  47                 .proc_handler = proc_dointvec,
  48         },
  49         {
  50                 .procname = "add_addr_timeout",
  51                 .maxlen = sizeof(unsigned int),
  52                 .mode = 0644,
  53                 .proc_handler = proc_dointvec_jiffies,
  54         },
  55         {}
  56 };
  57
  58 static void mptcp_pernet_set_defaults(struct mptcp_pernet *pernet)
  59 {
  60         pernet->mptcp_enabled = 1;
  61         pernet->add_addr_timeout = TCP_RTO_MAX;
  62 }
  63
  64 static int mptcp_pernet_new_table(struct net *net, struct mptcp_pernet *pernet)
  65 {
  66         struct ctl_table_header *hdr;
  67         struct ctl_table *table;
  68
  69         table = mptcp_sysctl_table;
  70         if (!net_eq(net, &init_net)) {
  71                 table = kmemdup(table, sizeof(mptcp_sysctl_table), GFP_KERNEL);
  72                 if (!table)
  73                         goto err_alloc;
  74         }
  75
  76         table[0].data = &pernet->mptcp_enabled;
  77         table[1].data = &pernet->add_addr_timeout;
  78
  79         hdr = register_net_sysctl(net, MPTCP_SYSCTL_PATH, table);
  80         if (!hdr)
  81                 goto err_reg;
  82
  83         pernet->ctl_table_hdr = hdr;
  84
  85         return 0;
  86
  87 err_reg:
  88         if (!net_eq(net, &init_net))
  89                 kfree(table);
  90 err_alloc:
  91         return -ENOMEM;
  92 }
  93
  94 static void mptcp_pernet_del_table(struct mptcp_pernet *pernet)
  95 {
  96         struct ctl_table *table = pernet->ctl_table_hdr->ctl_table_arg;
  97
  98         unregister_net_sysctl_table(pernet->ctl_table_hdr);
  99
 100         kfree(table);
 101 }
 102
 103 static int __net_init mptcp_net_init(struct net *net)
 104 {
 105         struct mptcp_pernet *pernet = mptcp_get_pernet(net);
 106
 107         mptcp_pernet_set_defaults(pernet);
 108
 109         return mptcp_pernet_new_table(net, pernet);
 110 }
 111
 112 /* Note: the callback will only be called per extra netns */
 113 static void __net_exit mptcp_net_exit(struct net *net)
 114 {
 115         struct mptcp_pernet *pernet = mptcp_get_pernet(net);
 116
 117         mptcp_pernet_del_table(pernet);
 118 }
 119
 120 static struct pernet_operations mptcp_pernet_ops = {
 121         .init = mptcp_net_init,
 122         .exit = mptcp_net_exit,
 123         .id = &mptcp_pernet_id,
 124         .size = sizeof(struct mptcp_pernet),
 125 };
 126
 127 void __init mptcp_init(void)
 128 {
 129         mptcp_join_cookie_init();
 130         mptcp_proto_init();
 131
 132         if (register_pernet_subsys(&mptcp_pernet_ops) < 0)
 133                 panic("Failed to register MPTCP pernet subsystem.\n");
 134 }
 135
 136 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
 137 int __init mptcpv6_init(void)
 138 {
 139         int err;
 140
 141         err = mptcp_proto_v6_init();
 142
 143         return err;
 144 }
 145 #endif