ppp-comp.h 2.4 KB

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  1. /*
  2. * ppp-comp.h - Definitions for doing PPP packet compression.
  3. *
  4. * Copyright 1994-1998 Paul Mackerras.
  5. *
  6. * This program is free software; you can redistribute it and/or
  7. * modify it under the terms of the GNU General Public License
  8. * version 2 as published by the Free Software Foundation.
  9. */
  10. #ifndef _NET_PPP_COMP_H
  11. #define _NET_PPP_COMP_H
  12. /*
  13. * CCP codes.
  14. */
  15. #define CCP_CONFREQ 1
  16. #define CCP_CONFACK 2
  17. #define CCP_TERMREQ 5
  18. #define CCP_TERMACK 6
  19. #define CCP_RESETREQ 14
  20. #define CCP_RESETACK 15
  21. /*
  22. * Max # bytes for a CCP option
  23. */
  24. #define CCP_MAX_OPTION_LENGTH 32
  25. /*
  26. * Parts of a CCP packet.
  27. */
  28. #define CCP_CODE(dp) ((dp)[0])
  29. #define CCP_ID(dp) ((dp)[1])
  30. #define CCP_LENGTH(dp) (((dp)[2] << 8) + (dp)[3])
  31. #define CCP_HDRLEN 4
  32. #define CCP_OPT_CODE(dp) ((dp)[0])
  33. #define CCP_OPT_LENGTH(dp) ((dp)[1])
  34. #define CCP_OPT_MINLEN 2
  35. /*
  36. * Definitions for BSD-Compress.
  37. */
  38. #define CI_BSD_COMPRESS 21 /* config. option for BSD-Compress */
  39. #define CILEN_BSD_COMPRESS 3 /* length of config. option */
  40. /* Macros for handling the 3rd byte of the BSD-Compress config option. */
  41. #define BSD_NBITS(x) ((x) & 0x1F) /* number of bits requested */
  42. #define BSD_VERSION(x) ((x) >> 5) /* version of option format */
  43. #define BSD_CURRENT_VERSION 1 /* current version number */
  44. #define BSD_MAKE_OPT(v, n) (((v) << 5) | (n))
  45. #define BSD_MIN_BITS 9 /* smallest code size supported */
  46. #define BSD_MAX_BITS 15 /* largest code size supported */
  47. /*
  48. * Definitions for Deflate.
  49. */
  50. #define CI_DEFLATE 26 /* config option for Deflate */
  51. #define CI_DEFLATE_DRAFT 24 /* value used in original draft RFC */
  52. #define CILEN_DEFLATE 4 /* length of its config option */
  53. #define DEFLATE_MIN_SIZE 9
  54. #define DEFLATE_MAX_SIZE 15
  55. #define DEFLATE_METHOD_VAL 8
  56. #define DEFLATE_SIZE(x) (((x) >> 4) + 8)
  57. #define DEFLATE_METHOD(x) ((x) & 0x0F)
  58. #define DEFLATE_MAKE_OPT(w) ((((w) - 8) << 4) + DEFLATE_METHOD_VAL)
  59. #define DEFLATE_CHK_SEQUENCE 0
  60. /*
  61. * Definitions for MPPE.
  62. */
  63. #define CI_MPPE 18 /* config option for MPPE */
  64. #define CILEN_MPPE 6 /* length of config option */
  65. /*
  66. * Definitions for other, as yet unsupported, compression methods.
  67. */
  68. #define CI_PREDICTOR_1 1 /* config option for Predictor-1 */
  69. #define CILEN_PREDICTOR_1 2 /* length of its config option */
  70. #define CI_PREDICTOR_2 2 /* config option for Predictor-2 */
  71. #define CILEN_PREDICTOR_2 2 /* length of its config option */
  72. #endif /* _NET_PPP_COMP_H */