ZX25CALLACC (3X) — ACC X.25

NAME

zx25callacc - Confirm (accept) an inbound call

SYNOPSIS

#include  <zcom/zcomsys.h>
#include  <zcom/zcomx25.h>    
 
int zx25callacc (zxip, vzap, fbuf, flen,
                          ubuf, ulen, dbit, clngaddr, caldaddr)
zx25info_type     *zxip;
zaddr_type        *vzap;
char              *fbuf;
int               flen;
char              *ubuf;
int               ulen;
int               dbit;
char              *clngaddr;
char              *caldaddr;

DESCRIPTION

Routine zx25callacc is used to confirm (accept) an inbound X.25 call. The caller of this routine is responsible for performing any required facilities and D-bit negotiation.

The libraries libzx25.a, libzcom_c.a and libpthread.a must be linked into the calling program by giving the "-lzx25 -lzcom_c -lpthread" options to cc(1) or ld(1).

Threads Considerations

This routine may be called from a multi-threaded application using the POSIX (1003.1c) kernel threads API package. It has the following characteristics when called by multi-threaded applications:

cancellation point: Thread cancellation can occur when a thread calls this routine.
async-cancel unsafe: The calling thread's cancelability type must be PTHREAD_CANCEL_DEFERRED if cancellation is enabled.
async-signal unsafe: It cannot be called from a signal handler.
fork unsafe: It cannot be called by a child process after fork(2) but before exec(2).

See the following NOTES section for more information on using this routine in a multi-threaded application.

PARAMETERS:

zxip: ZCOM X.25 access data structure (from zx25info call).
vzap: ZCOM address of the Virtual Circuit (terminal ZLU).
fbuf: Facilities data buffer.
flen: Facilities data length (in bytes).
ubuf: Call user data buffer.
ulen: Call user data length (in bytes).
dbit: D-bit (Only used for 1988 D-bit negotiation)
0 - no D-bit (set to 0)
non-zero - D-bit set to 1
clngaddr: User-supplied calling address buffer (if NULL, calling address not supplied). See Notes below for its format.
caldaddr: User-supplied called address buffer (if NULL, called address not supplied). See Notes below for its format.

RETURN VALUE

Routine zx25callacc returns a 0 when successful. If there was a ZCOM error, it returns a negative value. See /opt/acc/include/zcom/zcomsys.h for the list of ZCOM error codes and their meanings. If zx25callacc itself failed, one of the following positive error codes is returned:

ZxeUNKNOWN_L2_ZLU (02)

Unable to find the X.25 link ZLU for this SVC ZLU.

ZxeREQ_TIMEOUT (04)

The remote ZCOM system did not respond within 30 seconds.

ZxeNOT_A_SVC (05)

The ZLU specified is a PVC ZLU. You must specify an SVC ZLU with this routine.

ZxeNO_INBOUND_CALL (06)

This virtual circuit ZLU does not have a pending inbound call to accept.

ZxeLINK_IS_DOWN (11)

The X.25 link is down. Unable to accept call.

ZxeUNKNOWN_VC_ZLU (13)

The ZLU specified is not an X.25 Virtual Circuit ZLU.

ZxeINVALID_CUD_LEN (14)

The length specified for the Call User data is longer than the maximum permissible value (usually 128 bytes).

ZxeINVALID_FAC_LEN (15)

The length specified for the Facilities data is longer than the maximum permissible value (usually 109 bytes).

ZxeRESTRICT_FAS_SEL (16)

Restricted fast-select facility was specified in the inbound call.

You may only send a clear request. That is, it is illegal to accept the inbound call.

ZxeMUST_CALL_ZX25INFO (17)

The zx25info() routine has not been called. You must call zx25info before issuing any other zx25...() calls.

ZxeBAD_ZX25INFO_ADDR (18)

The pointer to the zx25info_type structure does not contain the same address that was passed to the zx25info() routine.

ZxeX25_NOT_INITIALIZED (98)

The ACC X.25 subsystem has not been initialized. You must run zx25d_init before issuing any zx25...() calls.

ZxeX25_TBL_FULL (99)

The X.25 routines maintain an internal table for accessing remote ZCOM nodes. This table has room to access up to 20 different ZCOM nodes (including the local node). This request attempted to access the 21st ZCOM remote node and the internal table used had insufficient space to save the routing data.

NOTES

The X.121 call address consists of 8 bytes, and it is used a a 15-digit BCD number plus a length digit in the last position. For example, in hex:
DD DD DD DD DD DD DD DL
where D is a 4-bit BCD digit, whose range is from 0 to 9
L is a 4-bit length digit, whose range is from 1 to 15
The 15 address digits should be left-justified and without leading zero. The length digit indicates the number of address digits. For example, to specify addresses "1773648" and "123456789012", the hex values of the address buffer should be:
17 73 64 8X XX XX XX X7 for 1773648
12 34 56 78 90 12 XX XC for 123456789012
where X is unused digit (normally should be set to zero).
The calling program (or thread) must call zx25info before calling this routine. In a multi-threaded application, each thread must make a separate call to zx25info using a per-thread ZCOM X.25 access data buffer zxip. The per-thread data buffer can then be used to call this routine.

EXAMPLE

#include<zcom/zcomsys.h>
#include<zcom/zcomx25.h>
 
int                 ierr;
zx25info_type       zxi;
zaddr_type          vzaddr;
char                fbuf[size];     /* user-defined size */
int                 flen;
char                ubuf[size];     /* user-defined size */
int                 ulen;
int                 dbit;
unsigned char       clngaddr[8];    /* user-defined size */
unsigned char       caldaddr[8];    /* user-defined size */
 
if (ierr = zx25callacc  (&zxi, &vzaddr, fbuf, flen, ubuf, 
     ulen, dbit, clngaddr, caldaddr)) {
/* error return code */
}
else {
/* good return code */
}

FILES

/opt/acc/include/zcom/zcomsys.h: ZCOM subsystem general include file, containing data types, data structures, constants, error codes, masks, etc. Note that this must be the first include file before any other ZCOM include files.
/opt/acc/include/zcom/zcomx25.h: ZCOM X.25 access data structures.