libosmo-tcap/src/csl_cha_ism.c

/* ITU-T Q.77x TCAP / ISM - Invocation State Machine,
 * part of CHA (ComponentHAndling), part of CSL (Component Sub-Layer) */

#include <osmocore/talloc.h>
#include <osmocore/msgb.h>

#include "tcap.h"

struct tcap_invocation *tcap_ism_lookup(struct tcap_dialogue *td, int8_t invoke_id)
{
	struct tcap_invocation *ti;
	llist_for_each_entry(ti, &td->ism_list, list) {
		if (ti->invoke_id == invoke_id)
			return ti;
	}
	return NULL:
}

struct tcap_invocation *tcap_ism_alloc(struct tcap_dialogue *td, int8_t invoke_id)
{
	struct tcap_invocation *ti = talloc_zero(td, struct tcap_invocation);
	if (!ti)
		return NULL;
	ti->invoke_id = invoke_id;
	ti->linked_id = -1234;
	ti->dialogue = td;
	ti->state = TCAP_IS_IDLE;

	llist_add(&ti->list, &td->ism_list);

	return ti;
}

void tcap_ism_free(struct tcap_invocation *ti)
{
	llist_del(&ti->list);
	talloc_free(ti);
}

/* Invocation timer expiry */
static int tcap_ism_inv_timer_exp(void *_ti)
{
	struct tcap_invocation *ti = _ti;

	switch (ti->state) {
	case TCAP_IS_OP_SENT_CL1:
	case TCAP_IS_OP_SENT_CL2:
	case TCAP_IS_OP_SENT_CL3:
	case TCAP_IS_OP_SENT_CL4:
		/* TC-L-CANCEL.ind (TCU <- CHA) */
		ti->state = TI_IS_INVALID;
		llist_del(&ti->list);
		talloc_free(ti);
		break;
	default:
		return -EINVAL;
	}

	return 0;
}

/* Reject timer expiry */
static int tcap_ism_rej_timer_exp(void *_ti)
{
	struct tcap_invocation *ti = _ti;

	if (state != TCAP_IS_WAIT_REJECT)
		return -EINVAL;

	ti->state = TI_IS_INVALID;
	llist_del(&ti->list);
	talloc_free(ti);

	return 0;
}

/* Operation sent (CCO -> ISM) */
int tcap_ism_op_sent(struct tcap_invocation *ti, uint8_t op_class)
{
	/* Start invocation timer */
	ti->inv_timer.cb = tcap_ism_inv_timer_exp;
	ti->inv_timer.data = ti;
	bsc_schedule_timer(&ti->inv_timer, sec, usec);

	switch (op_class) {
	case 1:
		ti->state = TCAP_IS_OP_SENT_CL1;
		break;
	case 2:
		ti->state = TCAP_IS_OP_SENT_CL2;
		break;
	case 3:
		ti->state = TCAP_IS_OP_SENT_CL3;
		break;
	case 4:
		ti->state = TCAP_IS_OP_SENT_CL4;
		break;
	default:
		return -EINVAL;
	}
}

/* RR-L received (CCO -> ISM) */
int tcap_ism_rr_l_recv(struct tcap_invocation *ti)
{
	int rc = 0;

	switch (ti->state) {
	case TCAP_IS_OP_SENT_CL1:
	case TCAP_IS_OP_SENT_CL3:
		/* TC-RESULT-L.ind (TCU <- CHA) */
		rc = tcap_tcu_result_l_ind();
		/* Stop invocation timer */
		bsc_del_timer(&ti->inv_timer);
		/* Start reject timer */
		ti->rej_timer.cb = tcap_ism_rej_timer_exp;
		ti->rej_timer.data = ti;
		bsc_schedule_timer(&ti->rej_timer, sec, usec);
		ti->state = TCAP_IS_WAIT_REJECT;
		break;
	case TCAP_IS_OP_SENT_CL2:
	case TCAP_IS_OP_SENT_CL4:
		/* Generate RJ component (CCO <- ISM) */
		rc = tcap_cco_gen_rej(ti);
		/* Stop invocation timer */
		bsc_del_timer(&ti->inv_timer);
		ti->state = TCAP_IS_INVALID;
		llist_del(&ti->list);
		talloc_free(ti);
		break;
	}
}

/* RE received (CCO -> ISM) */
int tcap_ism_re_recv(struct tcap_invocation *ti)
{
	switch (ti->state) {
	case TCAP_IS_OP_SENT_CL1:
	case TCAP_IS_OP_SENT_CL2:
		/* TC-U-ERROR.ind (TCU <- CHA) */
		/* Stop invocation timer */
		bsc_del_timer(&ti->inv_timer);
		/* Start reject timer */
		ti->rej_timer.cb = tcap_ism_rej_timer_exp;
		ti->rej_timer.data = ti;
		bsc_schedule_timer(&ti->rej_timer, sec, usec);
		ti->state = TCAP_IS_WAIT_REJECT;
		break;
	case TCAP_IS_OP_SENT_CL3:
	case TCAP_IS_OP_SENT_CL4:
		ti->state = TCAP_IS_INVALID;
		llist_del(&ti->list);
		talloc_free(ti);
		break;
	default:
		return -EINVAL;
	}

	return 0;
}

/* RR-NL received (CCO -> ISM) */
int tcap_ism_rr_nl_recv(struct tcap_invocation *ti)
{
	int rc = 0;

	switch (ti->state) {
	case TCAP_IS_OP_SENT_CL1:
	case TCAP_IS_OP_SENT_CL3:
		/* TC-RESULT-NL.ind (TCU <- CHA) */
		rc = tcap_tcu_result_nl_ind();
		/* stay in SENT_CL1 state */
		break;
	case TCAP_IS_OP_SENT_CL2:
	case TCAP_IS_OP_SENT_CL4:
		/* Generate RJ component (CCO <- ISM) */
		rc = tcap_cco_gen_rej(ti);
		/* Stop invocation timer */
		bsc_del_timer(&ti->inv_timer);
		ti->state = TCAP_IS_INVALID;
		llist_del(&ti->list);
		talloc_free(ti);
		break;
	default:	
		return -EINVAL;
	}

	return rc;
}

/* Terminate (CCO -> ISM) */
int tcap_ism_terminate(struct tcap_invocation *ti)
{
	switch (ti->state) {
	case TCAP_IS_OP_SENT_CL1:
	case TCAP_IS_OP_SENT_CL2:
	case TCAP_IS_OP_SENT_CL3:
	case TCAP_IS_OP_SENT_CL4:
	case TCAP_IS_WAIT_REJECT:
		break;
	default:
		return -EINVAL;
	}

	/* Stop invoation timer */
	bsc_del_timer(&ti->inv_timer);

	ti->state = TCAP_IS_INVALID;
	llist_del(&ti->list);
	talloc_free(ti);

	return 0;
}