tirdwr(M)


tirdwr -- Transport Interface read/write interface STREAMS module

Description

tirdwr is a STREAMS module that provides an alternate interface to a transport provider which supports the Transport Interface (TI) functions of the Network Services library (see Section 3N). This alternate interface allows a user to communicate with the transport protocol provider using the read(S) and write(S) system calls. The putmsg(S) and getmsg(S) system calls may also be used. However, putmsg and getmsg can only transfer data messages between user and stream.

The tirdwr module must only be pushed [see I_PUSH in streamio(HW)] onto a stream terminated by a transport protocol provider which supports the TI. After the tirdwr module has been pushed onto a stream, none of the Transport Interface functions can be used. Subsequent calls to TI functions will cause an error on the stream. Once the error is detected, subsequent system calls on the stream will return an error with errno set to EPROTO.

The following are the actions taken by the tirdwr module when pushed on the stream, popped, see I_POP in streamio(HW) off the stream, or when data passes through it.


push
When the module is pushed onto a stream, it will check any existing data destined for the user to ensure that only regular data messages are present. It will ignore any messages on the stream that relate to process management, such as messages that generate signals to the user processes associated with the stream. If any other messages are present, the I_PUSH will return an error with errno set to EPROTO.

write
The module will take the following actions on data that originated from a write system call:

read
The module will take the following actions on data that originated from the transport protocol provider:

pop
When the module is popped off the stream or the stream is closed, the module will take the following action:

References

getmsg(S), intro(S), intro(NET), putmsg(S), read(S), streamio(HW), timod(M), write(S)
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