venti-server 2.1 KB

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  1. .TH VENTI-SERVER 2
  2. .SH NAME
  3. vtsrvhello, vtlisten, vtgetreq, vtrespond \- Venti server
  4. .SH SYNOPSIS
  5. .PP
  6. .ft L
  7. #include <u.h>
  8. .br
  9. #include <libc.h>
  10. .br
  11. #include <venti.h>
  12. .ta +\w'\fLVtReq* 'u
  13. .PP
  14. .ft L
  15. .nf
  16. typedef struct VtReq
  17. {
  18. VtFcall tx;
  19. VtFcall rx;
  20. ...
  21. } VtReq;
  22. .PP
  23. .B
  24. int vtsrvhello(VtConn *z)
  25. .PP
  26. .B
  27. VtSrv* vtlisten(char *addr)
  28. .PP
  29. .B
  30. VtReq* vtgetreq(VtSrv *srv)
  31. .PP
  32. .B
  33. void vtrespond(VtReq *req)
  34. .SH DESCRIPTION
  35. These routines execute the server side of the
  36. .IR venti (6)
  37. protocol.
  38. .PP
  39. .I Vtsrvhello
  40. executes the server side of the initial
  41. .B hello
  42. transaction.
  43. It sets
  44. .IB z -> uid
  45. with the user name claimed by the other side.
  46. Each new connection must be initialized by running
  47. .I vtversion
  48. and then
  49. .IR vtsrvhello .
  50. The framework below takes care of this detail automatically;
  51. .I vtsrvhello
  52. is provided for programs that do not use the functions below.
  53. .PP
  54. .IR Vtlisten ,
  55. .IR vtgetreq ,
  56. and
  57. .I vtrespond
  58. provide a simple framework for writing Venti servers.
  59. .PP
  60. .I Vtlisten
  61. announces at the network address
  62. .IR addr ,
  63. returning a fresh
  64. .B VtSrv
  65. structure representing the service.
  66. .PP
  67. .I Vtgetreq
  68. waits for and returns
  69. the next
  70. .BR read ,
  71. .BR write ,
  72. .BR sync ,
  73. or
  74. .B ping
  75. request from any client connected to
  76. the service
  77. .IR srv .
  78. .B Hello
  79. and
  80. .B goodbye
  81. messages are handled internally and not returned to the client.
  82. The interface does not distinguish between the
  83. different clients that may be connected at any given time.
  84. The request can be found in the
  85. .I tx
  86. field of the returned
  87. .BR VtReq .
  88. .PP
  89. Once a request has been served and a response stored in
  90. .IB r ->rx \fR,
  91. the server should call
  92. .IR vtrespond
  93. to send the response to the client.
  94. .I Vtrespond
  95. frees the structure
  96. .I r
  97. as well as the packets
  98. .IB r ->tx.data
  99. and
  100. .IB r ->rx.data \fR.
  101. .SH EXAMPLE
  102. .B /sys/src/venti/cmd
  103. contains two simple Venti servers
  104. .B ro.c
  105. and
  106. .B devnull.c
  107. written using these routines.
  108. .I Ro
  109. is a read-only Venti proxy (it rejects
  110. .B write
  111. requests).
  112. .I Devnull
  113. is a dangerous write-only Venti server: it discards all
  114. blocks written to it and returns error on all reads.
  115. .SH SOURCE
  116. .B /sys/src/libventi
  117. .SH SEE ALSO
  118. .IR venti (2),
  119. .IR venti-conn (2),
  120. .IR venti-packet (2),
  121. .IR venti (6),
  122. .IR venti (8)