/net/plap/clone /net/plap/n/ctl /net/plap/n/data /net/plap/n/local /net/plap/n/remote /net/plap/n/status /net/plap/n/listen
The top level directory contains a single directory naming the protocol, plap. It contains a clone file and a set of conversation directories numbered from 0 to 127; only active conversation directories are present.
Opening the clone file allocates a new conversation directory n. The file descriptor will point to the control file, ctl, of that directory. Reading the file returns a text string giving the conversation number.
Each conversation directory contains six files. The connection is controlled by writing text strings to the ctl file. Once a connection has been established, data is exchanged with the remote peer by reading and writing the data file.
A plap address has the form:
where slot is a chassis slot number, chan is a logical channel (eg, a modem number), and sap is a number representing a `service access point'.
The following control messages are supported:
The remote and local files contain the remote and local addresses for the connection in the full address form slot.chan!sap. The status file returns a line giving the directory name, number of active opens, and the state of the connection.
A process listens for incoming calls by opening the listen file using sys-open(2). The open will block until a call arrives, when it will return a file descriptor open on the ctl file of the newly accepted connection, which can be read to find the directory number and thus the other files.
The device follows the conventions that allow dial, announce and listen of dial(2) to do the work needed to establish and manipulate network connections.
|PLAP(3 )||Rev: Tue Mar 31 02:42:38 GMT 2015|