sysctl_net.c 2.5 KB

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  1. /* -*- linux-c -*-
  2. * sysctl_net.c: sysctl interface to net subsystem.
  3. *
  4. * Begun April 1, 1996, Mike Shaver.
  5. * Added /proc/sys/net directories for each protocol family. [MS]
  6. *
  7. * Revision 1.2 1996/05/08 20:24:40 shaver
  8. * Added bits for NET_BRIDGE and the NET_IPV4_ARP stuff and
  9. * NET_IPV4_IP_FORWARD.
  10. *
  11. *
  12. */
  13. #include <linux/mm.h>
  14. #include <linux/export.h>
  15. #include <linux/sysctl.h>
  16. #include <linux/nsproxy.h>
  17. #include <net/sock.h>
  18. #ifdef CONFIG_INET
  19. #include <net/ip.h>
  20. #endif
  21. #ifdef CONFIG_NET
  22. #include <linux/if_ether.h>
  23. #endif
  24. #ifdef CONFIG_TR
  25. #include <linux/if_tr.h>
  26. #endif
  27. static struct ctl_table_set *
  28. net_ctl_header_lookup(struct ctl_table_root *root, struct nsproxy *namespaces)
  29. {
  30. return &namespaces->net_ns->sysctls;
  31. }
  32. static int is_seen(struct ctl_table_set *set)
  33. {
  34. return &current->nsproxy->net_ns->sysctls == set;
  35. }
  36. /* Return standard mode bits for table entry. */
  37. static int net_ctl_permissions(struct ctl_table_root *root,
  38. struct nsproxy *nsproxy,
  39. struct ctl_table *table)
  40. {
  41. /* Allow network administrator to have same access as root. */
  42. if (capable(CAP_NET_ADMIN)) {
  43. int mode = (table->mode >> 6) & 7;
  44. return (mode << 6) | (mode << 3) | mode;
  45. }
  46. return table->mode;
  47. }
  48. static struct ctl_table_root net_sysctl_root = {
  49. .lookup = net_ctl_header_lookup,
  50. .permissions = net_ctl_permissions,
  51. };
  52. static int __net_init sysctl_net_init(struct net *net)
  53. {
  54. setup_sysctl_set(&net->sysctls, &net_sysctl_root, is_seen);
  55. return 0;
  56. }
  57. static void __net_exit sysctl_net_exit(struct net *net)
  58. {
  59. retire_sysctl_set(&net->sysctls);
  60. }
  61. static struct pernet_operations sysctl_pernet_ops = {
  62. .init = sysctl_net_init,
  63. .exit = sysctl_net_exit,
  64. };
  65. static struct ctl_table_header *net_header;
  66. __init int net_sysctl_init(void)
  67. {
  68. static struct ctl_table empty[1];
  69. int ret = -ENOMEM;
  70. /* Avoid limitations in the sysctl implementation by
  71. * registering "/proc/sys/net" as an empty directory not in a
  72. * network namespace.
  73. */
  74. net_header = register_sysctl("net", empty);
  75. if (!net_header)
  76. goto out;
  77. ret = register_pernet_subsys(&sysctl_pernet_ops);
  78. if (ret)
  79. goto out;
  80. register_sysctl_root(&net_sysctl_root);
  81. out:
  82. return ret;
  83. }
  84. struct ctl_table_header *register_net_sysctl(struct net *net,
  85. const char *path, struct ctl_table *table)
  86. {
  87. return __register_sysctl_table(&net->sysctls, path, table);
  88. }
  89. EXPORT_SYMBOL_GPL(register_net_sysctl);
  90. void unregister_net_sysctl_table(struct ctl_table_header *header)
  91. {
  92. unregister_sysctl_table(header);
  93. }
  94. EXPORT_SYMBOL_GPL(unregister_net_sysctl_table);