remarkable-linux/include/linux/x25.h
Shaun Pereira ebc3f64b86 [X25]: Fast select with no restriction on response
This patch is a follow up to patch 1 regarding "Selective Sub Address
matching with call user data".  It allows use of the Fast-Select-Acceptance
optional user facility for X.25.

This patch just implements fast select with no restriction on response
(NRR).  What this means (according to ITU-T Recomendation 10/96 section
6.16) is that if in an incoming call packet, the relevant facility bits are
set for fast-select-NRR, then the called DTE can issue a direct response to
the incoming packet using a call-accepted packet that contains
call-user-data.  This patch allows such a response.  

The called DTE can also respond with a clear-request packet that contains
call-user-data.  However, this feature is currently not implemented by the
patch.

How is Fast Select Acceptance used?
By default, the system does not allow fast select acceptance (as before).
To enable a response to fast select acceptance,  
After a listen socket in created and bound as follows
	socket(AF_X25, SOCK_SEQPACKET, 0);
	bind(call_soc, (struct sockaddr *)&locl_addr, sizeof(locl_addr));
but before a listen system call is made, the following ioctl should be used.
	ioctl(call_soc,SIOCX25CALLACCPTAPPRV);
Now the listen system call can be made
	listen(call_soc, 4);
After this, an incoming-call packet will be accepted, but no call-accepted 
packet will be sent back until the following system call is made on the socket
that accepts the call
	ioctl(vc_soc,SIOCX25SENDCALLACCPT);
The network (or cisco xot router used for testing here) will allow the 
application server's call-user-data in the call-accepted packet, 
provided the call-request was made with Fast-select NRR.

Signed-off-by: Shaun Pereira <spereira@tusc.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-22 22:16:17 -07:00

125 lines
2.8 KiB
C

/*
* These are the public elements of the Linux kernel X.25 implementation.
*
* History
* mar/20/00 Daniela Squassoni Disabling/enabling of facilities
* negotiation.
* apr/02/05 Shaun Pereira Selective sub address matching with
* call user data
*/
#ifndef X25_KERNEL_H
#define X25_KERNEL_H
#define SIOCX25GSUBSCRIP (SIOCPROTOPRIVATE + 0)
#define SIOCX25SSUBSCRIP (SIOCPROTOPRIVATE + 1)
#define SIOCX25GFACILITIES (SIOCPROTOPRIVATE + 2)
#define SIOCX25SFACILITIES (SIOCPROTOPRIVATE + 3)
#define SIOCX25GCALLUSERDATA (SIOCPROTOPRIVATE + 4)
#define SIOCX25SCALLUSERDATA (SIOCPROTOPRIVATE + 5)
#define SIOCX25GCAUSEDIAG (SIOCPROTOPRIVATE + 6)
#define SIOCX25SCUDMATCHLEN (SIOCPROTOPRIVATE + 7)
#define SIOCX25CALLACCPTAPPRV (SIOCPROTOPRIVATE + 8)
#define SIOCX25SENDCALLACCPT (SIOCPROTOPRIVATE + 9)
/*
* Values for {get,set}sockopt.
*/
#define X25_QBITINCL 1
/*
* X.25 Packet Size values.
*/
#define X25_PS16 4
#define X25_PS32 5
#define X25_PS64 6
#define X25_PS128 7
#define X25_PS256 8
#define X25_PS512 9
#define X25_PS1024 10
#define X25_PS2048 11
#define X25_PS4096 12
/*
* An X.121 address, it is held as ASCII text, null terminated, up to 15
* digits and a null terminator.
*/
struct x25_address {
char x25_addr[16];
};
/*
* Linux X.25 Address structure, used for bind, and connect mostly.
*/
struct sockaddr_x25 {
sa_family_t sx25_family; /* Must be AF_X25 */
struct x25_address sx25_addr; /* X.121 Address */
};
/*
* DTE/DCE subscription options.
*
* As this is missing lots of options, user should expect major
* changes of this structure in 2.5.x which might break compatibilty.
* The somewhat ugly dimension 200-sizeof() is needed to maintain
* backward compatibility.
*/
struct x25_subscrip_struct {
char device[200-sizeof(unsigned long)];
unsigned long global_facil_mask; /* 0 to disable negotiation */
unsigned int extended;
};
/* values for above global_facil_mask */
#define X25_MASK_REVERSE 0x01
#define X25_MASK_THROUGHPUT 0x02
#define X25_MASK_PACKET_SIZE 0x04
#define X25_MASK_WINDOW_SIZE 0x08
/*
* Routing table control structure.
*/
struct x25_route_struct {
struct x25_address address;
unsigned int sigdigits;
char device[200];
};
/*
* Facilities structure.
*/
struct x25_facilities {
unsigned int winsize_in, winsize_out;
unsigned int pacsize_in, pacsize_out;
unsigned int throughput;
unsigned int reverse;
};
/*
* Call User Data structure.
*/
struct x25_calluserdata {
unsigned int cudlength;
unsigned char cuddata[128];
};
/*
* Call clearing Cause and Diagnostic structure.
*/
struct x25_causediag {
unsigned char cause;
unsigned char diagnostic;
};
/*
* Further optional call user data match length selection
*/
struct x25_subaddr {
unsigned int cudmatchlength;
};
#endif