ejabberd源码分析《三》客户端数据处理

参考 http://www.cnblogs.com/yjl49/archive/2011/09/02/2371964.html

1.客户端连接服务器后，发送消息给服务器的xml数据处理在ejabberd_c2s中。

?? ejabberd_c2s 是一个gen_fsm 状态机，在socket连接建立之后创建。

?? 初始状态为 wait_for_stream，接受形为 {xmlstreamstart,_Name,Attrs} 的消息，其他任何消息都会导致stop。

?? 接受到连接请求，发送feature 请求后状态改为wait_for_feature_request 。

?? 接受到feature 再发送challenge 后，状态改为 wait_for_sasl_response。

?? 经过sasl鉴权后，状态改为 wait_for_stream， 此时 StateData#state.authenticated 已经不为false。

?? 客户端重新发起<stream> 连接请求，服务器发送bind 消息，状态改为 wait_for_bind 。

?? 客户端发送bind 与资源绑定，服务器按照策略验证是否允许相同的用户用不同的资源连接，通过后状态改为 wait_for_session。

?? 客户端发送<iq> 消息创建session，服务器调用 ejabberd_sm:open_session 后将状态改为 session_established。

?? 客户端发送普通的通信消息<iq>，<presence>，<message> 等，都通过session_established2/2 函数处理。

1. %%?Process?packets?sent?by?user?(coming?from?user?on?c2s?XMPP??
2. %%?connection)??
3. session_established2(El,?StateData)?->??
4. ??
5. ????%%从变量El中取出Name,Attrs?两个参数,El必须是一个以xmlelement?为第一个元子的元组??
6. ????{xmlelement,?Name,?Attrs,?_Els}?=?El,??
7. ????%%从StateDate中取出user,server,jid???
8. ????User?=?StateData#state.user,??
9. ????Server?=?StateData#state.server,??
10. ????FromJID?=?StateData#state.jid,??
11. ??
12. ????%%从Attrs属性变量中获取to(也就是发送给谁)??
13. ????To?=?xml:get_attr_s("to",?Attrs),??
14. ???????
15. ????%%将To转换成一个标准的JID:??
16. ????%%#jid{user,resource,luser,lserver,lresource},具体参见jlib.erl中的定义??
17. ????ToJID?=?case?To?of??
18. ????????""?->??
19. ????????????jlib:make_jid(User,?Server,?"");??
20. ????????_?->??
21. ????????????jlib:string_to_jid(To)??
22. ????????end,??
23. ??
24. ????%%这里的El里的Attrs应该是一个元组组成的列表[{key1,value1},{key2,value2},{key3,value3},{key4,value4}.....]??
25. ????%%下面的语句会从Attrs中删除key?为xmlns的元组，并返回新的El存放到NewEl1中??
26. ????NewEl1?=?jlib:remove_attr("xmlns",?El),??
27. ????NewEl?=?case?xml:get_attr_s("xml:lang",?Attrs)?of??
28. ????????""?->??
29. ????????????case?StateData#state.lang?of??
30. ????????????""?->?NewEl1;??
31. ????????????Lang?->??
32. ????????????????xml:replace_tag_attr("xml:lang",?Lang,?NewEl1)??
33. ????????????end;??
34. ????????_?->??
35. ????????????NewEl1??
36. ????????end,??
37. ??
38. ????%%这里根据消息类型进行不同的处理??
39. ????NewState?=??
40. ????case?ToJID?of??
41. ????????error?->??
42. ????????case?xml:get_attr_s("type",?Attrs)?of??
43. ????????????"error"?->?StateData;??
44. ????????????"result"?->?StateData;??
45. ????????????_?->??
46. ????????????Err?=?jlib:make_error_reply(NewEl,??ERR_JID_MALFORMED),??
47. ????????????send_element(StateData,?Err),??
48. ????????????StateData??
49. ????????end;??
50. ????????_?->??
51. ????????case?Name?of??
52. ????????????"presence"?->??
53. ????????????????????????%%如果为一个presence?消息,使用函数回调c2s_updatepresence参见2??
54. ????????????????PresenceEl?=?ejabberd_hooks:run_fold(??
55. ???????????????????????c2s_update_presence,??
56. ???????????????????????Server,??
57. ???????????????????????NewEl,??
58. ???????????????????????[User,?Server]),??
59. ?????????????????
60. ??????????????????????????%%将调用结果发送回客户端??
61. ??????????????????????????ejabberd_hooks:run(??
62. ??????????????user_send_packet,??
63. ??????????????Server,??
64. ??????????????[FromJID,?ToJID,?PresenceEl]),??
65. ????????????case?ToJID?of??
66. ????????????????#jid{user?=?User,??
67. ?????????????????server?=?Server,??
68. ?????????????????resource?=?""}?->??
69. ?????????????????DEBUG("presence_update(~p,~nt~p,~nt~p)",??
70. ???????????????????????[FromJID,?PresenceEl,?StateData]),??
71. ????????????????presence_update(FromJID,??
72. ????????????????????????StateData);??
73. ????????????????_?->??
74. ????????????????presence_track(FromJID,??
75. ???????????????????????????StateData)??
76. ????????????end;??
77. ????????????"iq"?->??
78. ??????????????????????????%%iq?消息的处理.注册,添加好友等都是通过iq消息来发送的??
79. ??????????????????????????case?jlib:iq_query_info(NewEl)?of??
80. ????????????????#iq{xmlns?=?Xmlns}?=?IQ??
81. ????????????????when?Xmlns?==??NS_PRIVACY;??
82. ?????????????????Xmlns?==??NS_BLOCKING?->??
83. ????????????????process_privacy_iq(??
84. ??????????????????FromJID,?IQ,?StateData);??
85. ????????????????_?->??
86. ????????????????ejabberd_hooks:run(??
87. ??????????????????user_send_packet,??
88. ??????????????????Server,??
89. ??????????????????[FromJID,?NewEl]),??
90. ????????????????check_privacy_route(FromJID,?StateData,?FromJID,?NewEl),??
91. ????????????????StateData??
92. ????????????end;??
93. ????????????"message"?->??
94. ????????????????????????io:format("message?arrvied~n",[]),??
95. ????????????ejabberd_hooks:run(user_send_packet,??
96. ???????????????????????[FromJID,??
97. ????????????check_privacy_route(FromJID,??
98. ????????????????????????ToJID,??
99. ????????????StateData;??
100. ????????????_?->??
101. ????????????StateData??
102. ????????end??
103. ????end,??
104. ????ejabberd_hooks:run(c2s_loop_debug,?[{xmlstreamelement,?El}]),??
105. ????fsm_next_state(session_established,?NewState).??

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