protocol.c 2.3 KB

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  1. /*
  2. * INET An implementation of the TCP/IP protocol suite for the LINUX
  3. * operating system. INET is implemented using the BSD Socket
  4. * interface as the means of communication with the user level.
  5. *
  6. * INET protocol dispatch tables.
  7. *
  8. * Version: $Id: protocol.c,v 1.1.1.1 2007/06/12 07:27:14 eyryu Exp $
  9. *
  10. * Authors: Ross Biro
  11. * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  12. *
  13. * Fixes:
  14. * Alan Cox : Ahah! udp icmp errors don't work because
  15. * udp_err is never called!
  16. * Alan Cox : Added new fields for init and ready for
  17. * proper fragmentation (_NO_ 4K limits!)
  18. * Richard Colella : Hang on hash collision
  19. * Vince Laviano : Modified inet_del_protocol() to correctly
  20. * maintain copy bit.
  21. *
  22. * This program is free software; you can redistribute it and/or
  23. * modify it under the terms of the GNU General Public License
  24. * as published by the Free Software Foundation; either version
  25. * 2 of the License, or (at your option) any later version.
  26. */
  27. #include <asm/uaccess.h>
  28. #include <asm/system.h>
  29. #include <linux/module.h>
  30. #include <linux/types.h>
  31. #include <linux/kernel.h>
  32. #include <linux/string.h>
  33. #include <linux/socket.h>
  34. #include <linux/in.h>
  35. #include <linux/inet.h>
  36. #include <linux/netdevice.h>
  37. #include <linux/timer.h>
  38. #include <net/ip.h>
  39. #include <net/protocol.h>
  40. #include <linux/skbuff.h>
  41. #include <net/sock.h>
  42. #include <net/icmp.h>
  43. #include <net/udp.h>
  44. #include <net/ipip.h>
  45. #include <linux/igmp.h>
  46. struct net_protocol *inet_protos[MAX_INET_PROTOS];
  47. static DEFINE_SPINLOCK(inet_proto_lock);
  48. /*
  49. * Add a protocol handler to the hash tables
  50. */
  51. int inet_add_protocol(struct net_protocol *prot, unsigned char protocol)
  52. {
  53. int hash, ret;
  54. hash = protocol & (MAX_INET_PROTOS - 1);
  55. spin_lock_bh(&inet_proto_lock);
  56. if (inet_protos[hash]) {
  57. ret = -1;
  58. } else {
  59. inet_protos[hash] = prot;
  60. ret = 0;
  61. }
  62. spin_unlock_bh(&inet_proto_lock);
  63. return ret;
  64. }
  65. /*
  66. * Remove a protocol from the hash tables.
  67. */
  68. int inet_del_protocol(struct net_protocol *prot, unsigned char protocol)
  69. {
  70. int hash, ret;
  71. hash = protocol & (MAX_INET_PROTOS - 1);
  72. spin_lock_bh(&inet_proto_lock);
  73. if (inet_protos[hash] == prot) {
  74. inet_protos[hash] = NULL;
  75. ret = 0;
  76. } else {
  77. ret = -1;
  78. }
  79. spin_unlock_bh(&inet_proto_lock);
  80. synchronize_net();
  81. return ret;
  82. }
  83. EXPORT_SYMBOL(inet_add_protocol);
  84. EXPORT_SYMBOL(inet_del_protocol);