Provides access to the X.25 Interface Co-Processor/2 adapters by way of the X.25 Interface Co-Processor/2 device handler.
The x25sn character special file provides access to the X.25 Interface Co-Processor/2 device handler, which provides access to a X.25 packet switching network. The device handler supports up to four X.25 Interface Co-Processor/2 adapters.
When accessing the X.25 Interface Co-Processor/2 device handler, the following should be taken into account:
The X.25 Interface Co-Processor/2 device handler provides specific support for the open, close, read, write, and ioctl subroutines.
The device handler supports the /dev/x25sn special file as a character-multiplex special file. The special file must be opened for both reading and writing (O_RDWR). There are no particular considerations for closing the special file. The special file name used in an open call differs depending upon how the device is to be opened. For each of the following types of special files, the value n is 0 <= n <= 7:
Can take the form of a read, readx, readv, or readvx subroutine. For this call, the device handler copies the data into the buffer specified by the caller.
Can take the form of a write, writex, writev, or writevx subroutine. For this call, the device handler copies the user data into a kernel buffer and transmits the data on the network.
The device handler supports the following ioctl operations:
| CIO_DNLD | Downloads a task. | ||||||||
| CIO_GET_STAT | Gets device statistics. | ||||||||
| CIO_HALT | Halts a session. | ||||||||
| CIO_QUERY | Queries a device. | ||||||||
| CIO_START | Starts a session. | ||||||||
| IOCINFO | Identifies a device. | ||||||||
| X25_ADD_ROUTER_ID | Adds a router ID. | ||||||||
| X25_COUNTER_GET | Gets a counter. | ||||||||
| X25_COUNTER_READ | Reads the contents of a counter. | ||||||||
| X25_COUNTER_REMOVE | Removes a counter from the system. | ||||||||
| X25_COUNTER_WAIT | Waits for the contents of counters to change. | ||||||||
| X25_DELETE_ROUTER_ID | Deletes a router ID. | ||||||||
| X25_DIAG_IO_READ | Reads to an I/O register on the X.25 Interface Co-Processor/2. | ||||||||
| X25_DIAG_IO_WRITE | Writes to an I/O register on the X.25 Interface Co-Processor/2. | ||||||||
| X25_DIAG_MEM_READ | Reads memory from the X.25 Interface Co-Processor/2 into a user's buffer. | ||||||||
| X25_DIAG_MEM_WRITE | Writes memory to the X.25 Interface Co-Processor/2 from a user's buffer. | ||||||||
| X25_DIAG_TASK | Provides the means to download the diagnostics task on to the card. | ||||||||
| X25_LINK_CONNECT | Connects a link. | ||||||||
| X25_LINK_DISCONNECT | Disconnects a link. | ||||||||
| X25_LINK_STATUS | Returns the status of the link.
|
The following error conditions may be returned when accessing the device handler through the /dev/x25sn special file:
The close subroutine, open subroutine, read or readx subroutine, write or writex subroutine.