92 lines
3.1 KiB
Plaintext
92 lines
3.1 KiB
Plaintext
= Architecture of uHub =
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uHub is single-threaded and handles network and timer events using the
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libevent library.
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For each state there is a read event (and sometimes a write event) and timeout
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event in case an expected read (or write) event does not occur.
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== Protocol overview ==
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uHub "speaks" the ADC protocol, which works in short as follows:
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(C = client, S = server aka uHub).
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C: HSUP ADBASE
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Client connects to hub and supplies a list of supported features to the hub.
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S: ISUP ADBASE { }
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Server responds with a list of supported features.
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S: ISID xxxx
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Server assigns a session-ID to the client (4 bytes, BASE32 encoded).
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C: BINF xxxx (...)
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Client sends information about itself, such as nick name, etc.
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The hub will relay this information to all users, including the client.
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S: BINF xxx1 NInick1 (...)
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S: BINF xxx2 NInick2
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S: (...)
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S: BINF xxxx (client's own nick)
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Client gets list of other clients, which ends with the client's own user info.
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At this point the client is successfully logged into the hub.
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== The hub architecture ==
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Accepting new users
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--------------------- -----------------
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| Accept connection | <---------- | libevent loop |
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--------------------- -----------------
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V
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--------------------- ------------
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| Setup login timer | --+----> | Timeout? | <----+
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--------------------- | ------------ |
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V | V |
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--------------------- | --------------- |
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| Receive 'HSUP' | --+----> | DISCONNECT! | |
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--------------------- --------------- |
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| ^ |
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V | |
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--------------------- | |
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| Send 'ISUP', and | | |
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| assign Session ID | | |
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--------------------- | |
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--------------------- | |
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| Receive 'BINF' |-----------------+------------
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+--| Validate message | ^
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| --------------------- |
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| --------------------- ---------------------
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| | Send password | ------> | Receive and check |
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| | request, if needed| | password. |
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| --------------------- ---------------------
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| ------------------------ |
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+->| Send welcome message |<--------------+
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------------------------
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------------------------
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| Send user list to |
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| newly accepted user. |
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------------------------
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V
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------------------------
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| User is logged in. |
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| Announce to all. |
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------------------------
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