net/core/sysctl_net_core.c

   1 /* -*- linux-c -*-
   2  * sysctl_net_core.c: sysctl interface to net core subsystem.
   3  *
   4  * Begun April 1, 1996, Mike Shaver.
   5  * Added /proc/sys/net/core directory entry (empty =) ). [MS]
   6  */
   7
   8 #include <linux/mm.h>
   9 #include <linux/sysctl.h>
  10 #include <linux/module.h>
  11 #include <linux/socket.h>
  12 #include <linux/netdevice.h>
  13 #include <linux/ratelimit.h>
  14 #include <linux/vmalloc.h>
  15 #include <linux/init.h>
  16 #include <linux/slab.h>
  17 #include <linux/kmemleak.h>
  18
  19 #include <net/ip.h>
  20 #include <net/sock.h>
  21 #include <net/net_ratelimit.h>
  22
  23 static int zero = 0;
  24 static int one = 1;
  25 static int ushort_max = USHRT_MAX;
  26
  27 #ifdef CONFIG_RPS
  28 static int rps_sock_flow_sysctl(ctl_table *table, int write,
  29                                 void __user *buffer, size_t *lenp, loff_t *ppos)
  30 {
  31         unsigned int orig_size, size;
  32         int ret, i;
  33         ctl_table tmp = {
  34                 .data = &size,
  35                 .maxlen = sizeof(size),
  36                 .mode = table->mode
  37         };
  38         struct rps_sock_flow_table *orig_sock_table, *sock_table;
  39         static DEFINE_MUTEX(sock_flow_mutex);
  40
  41         mutex_lock(&sock_flow_mutex);
  42
  43         orig_sock_table = rcu_dereference_protected(rps_sock_flow_table,
  44                                         lockdep_is_held(&sock_flow_mutex));
  45         size = orig_size = orig_sock_table ? orig_sock_table->mask + 1 : 0;
  46
  47         ret = proc_dointvec(&tmp, write, buffer, lenp, ppos);
  48
  49         if (write) {
  50                 if (size) {
  51                         if (size > 1<<30) {
  52                                 /* Enforce limit to prevent overflow */
  53                                 mutex_unlock(&sock_flow_mutex);
  54                                 return -EINVAL;
  55                         }
  56                         size = roundup_pow_of_two(size);
  57                         if (size != orig_size) {
  58                                 sock_table =
  59                                     vmalloc(RPS_SOCK_FLOW_TABLE_SIZE(size));
  60                                 if (!sock_table) {
  61                                         mutex_unlock(&sock_flow_mutex);
  62                                         return -ENOMEM;
  63                                 }
  64
  65                                 sock_table->mask = size - 1;
  66                         } else
  67                                 sock_table = orig_sock_table;
  68
  69                         for (i = 0; i < size; i++)
  70                                 sock_table->ents[i] = RPS_NO_CPU;
  71                 } else
  72                         sock_table = NULL;
  73
  74                 if (sock_table != orig_sock_table) {
  75                         rcu_assign_pointer(rps_sock_flow_table, sock_table);
  76                         if (sock_table)
  77                                 static_key_slow_inc(&rps_needed);
  78                         if (orig_sock_table) {
  79                                 static_key_slow_dec(&rps_needed);
  80                                 synchronize_rcu();
  81                                 vfree(orig_sock_table);
  82                         }
  83                 }
  84         }
  85
  86         mutex_unlock(&sock_flow_mutex);
  87
  88         return ret;
  89 }
  90 #endif /* CONFIG_RPS */
  91
  92 static struct ctl_table net_core_table[] = {
  93 #ifdef CONFIG_NET
  94         {
  95                 .procname       = "wmem_max",
  96                 .data           = &sysctl_wmem_max,
  97                 .maxlen         = sizeof(int),
  98                 .mode           = 0644,
  99                 .proc_handler   = proc_dointvec_minmax,
 100                 .extra1         = &one,
 101         },
 102         {
 103                 .procname       = "rmem_max",
 104                 .data           = &sysctl_rmem_max,
 105                 .maxlen         = sizeof(int),
 106                 .mode           = 0644,
 107                 .proc_handler   = proc_dointvec_minmax,
 108                 .extra1         = &one,
 109         },
 110         {
 111                 .procname       = "wmem_default",
 112                 .data           = &sysctl_wmem_default,
 113                 .maxlen         = sizeof(int),
 114                 .mode           = 0644,
 115                 .proc_handler   = proc_dointvec_minmax,
 116                 .extra1         = &one,
 117         },
 118         {
 119                 .procname       = "rmem_default",
 120                 .data           = &sysctl_rmem_default,
 121                 .maxlen         = sizeof(int),
 122                 .mode           = 0644,
 123                 .proc_handler   = proc_dointvec_minmax,
 124                 .extra1         = &one,
 125         },
 126         {
 127                 .procname       = "dev_weight",
 128                 .data           = &weight_p,
 129                 .maxlen         = sizeof(int),
 130                 .mode           = 0644,
 131                 .proc_handler   = proc_dointvec
 132         },
 133         {
 134                 .procname       = "netdev_max_backlog",
 135                 .data           = &netdev_max_backlog,
 136                 .maxlen         = sizeof(int),
 137                 .mode           = 0644,
 138                 .proc_handler   = proc_dointvec
 139         },
 140 #ifdef CONFIG_BPF_JIT
 141         {
 142                 .procname       = "bpf_jit_enable",
 143                 .data           = &bpf_jit_enable,
 144                 .maxlen         = sizeof(int),
 145                 .mode           = 0644,
 146                 .proc_handler   = proc_dointvec
 147         },
 148 #endif
 149         {
 150                 .procname       = "netdev_tstamp_prequeue",
 151                 .data           = &netdev_tstamp_prequeue,
 152                 .maxlen         = sizeof(int),
 153                 .mode           = 0644,
 154                 .proc_handler   = proc_dointvec
 155         },
 156         {
 157                 .procname       = "message_cost",
 158                 .data           = &net_ratelimit_state.interval,
 159                 .maxlen         = sizeof(int),
 160                 .mode           = 0644,
 161                 .proc_handler   = proc_dointvec_jiffies,
 162         },
 163         {
 164                 .procname       = "message_burst",
 165                 .data           = &net_ratelimit_state.burst,
 166                 .maxlen         = sizeof(int),
 167                 .mode           = 0644,
 168                 .proc_handler   = proc_dointvec,
 169         },
 170         {
 171                 .procname       = "optmem_max",
 172                 .data           = &sysctl_optmem_max,
 173                 .maxlen         = sizeof(int),
 174                 .mode           = 0644,
 175                 .proc_handler   = proc_dointvec
 176         },
 177 #ifdef CONFIG_RPS
 178         {
 179                 .procname       = "rps_sock_flow_entries",
 180                 .maxlen         = sizeof(int),
 181                 .mode           = 0644,
 182                 .proc_handler   = rps_sock_flow_sysctl
 183         },
 184 #endif
 185 #endif /* CONFIG_NET */
 186         {
 187                 .procname       = "netdev_budget",
 188                 .data           = &netdev_budget,
 189                 .maxlen         = sizeof(int),
 190                 .mode           = 0644,
 191                 .proc_handler   = proc_dointvec
 192         },
 193         {
 194                 .procname       = "warnings",
 195                 .data           = &net_msg_warn,
 196                 .maxlen         = sizeof(int),
 197                 .mode           = 0644,
 198                 .proc_handler   = proc_dointvec
 199         },
 200         { }
 201 };
 202
 203 static struct ctl_table netns_core_table[] = {
 204         {
 205                 .procname       = "somaxconn",
 206                 .data           = &init_net.core.sysctl_somaxconn,
 207                 .maxlen         = sizeof(int),
 208                 .mode           = 0644,
 209                 .extra1         = &zero,
 210                 .extra2         = &ushort_max,
 211                 .proc_handler   = proc_dointvec_minmax
 212         },
 213         { }
 214 };
 215
 216 static __net_init int sysctl_core_net_init(struct net *net)
 217 {
 218         struct ctl_table *tbl;
 219
 220         net->core.sysctl_somaxconn = SOMAXCONN;
 221
 222         tbl = netns_core_table;
 223         if (!net_eq(net, &init_net)) {
 224                 tbl = kmemdup(tbl, sizeof(netns_core_table), GFP_KERNEL);
 225                 if (tbl == NULL)
 226                         goto err_dup;
 227
 228                 tbl[0].data = &net->core.sysctl_somaxconn;
 229
 230                 /* Don't export any sysctls to unprivileged users */
 231                 if (net->user_ns != &init_user_ns) {
 232                         tbl[0].procname = NULL;
 233                 }
 234         }
 235
 236         net->core.sysctl_hdr = register_net_sysctl(net, "net/core", tbl);
 237         if (net->core.sysctl_hdr == NULL)
 238                 goto err_reg;
 239
 240         return 0;
 241
 242 err_reg:
 243         if (tbl != netns_core_table)
 244                 kfree(tbl);
 245 err_dup:
 246         return -ENOMEM;
 247 }
 248
 249 static __net_exit void sysctl_core_net_exit(struct net *net)
 250 {
 251         struct ctl_table *tbl;
 252
 253         tbl = net->core.sysctl_hdr->ctl_table_arg;
 254         unregister_net_sysctl_table(net->core.sysctl_hdr);
 255         BUG_ON(tbl == netns_core_table);
 256         kfree(tbl);
 257 }
 258
 259 static __net_initdata struct pernet_operations sysctl_core_ops = {
 260         .init = sysctl_core_net_init,
 261         .exit = sysctl_core_net_exit,
 262 };
 263
 264 static __init int sysctl_core_init(void)
 265 {
 266         register_net_sysctl(&init_net, "net/core", net_core_table);
 267         return register_pernet_subsys(&sysctl_core_ops);
 268 }
 269
 270 fs_initcall(sysctl_core_init);