[apple/xnu.git] / bsd / netat / atp_misc.c

/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*
 *	Copyright (c) 1996-1998 Apple Computer, Inc.
 *	All Rights Reserved.
 */

/*    Modified for MP, 1996 by Tuyen Nguyen
 *   Modified, March 17, 1997 by Tuyen Nguyen for MacOSX.
 */
#include <sys/errno.h>
#include <sys/types.h>
#include <sys/param.h>
#include <machine/spl.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/filedesc.h>
#include <sys/fcntl.h>
#include <sys/mbuf.h>
#include <sys/ioctl.h>
#include <sys/malloc.h>
#include <sys/socket.h>

#include <netat/sysglue.h>
#include <netat/appletalk.h>
#include <netat/ddp.h>
#include <netat/at_pcb.h>
#include <netat/atp.h>
#include <netat/debug.h>

extern atlock_t atpgen_lock;
void atp_free();
void atp_send(struct atp_trans *);

/*
 *	The request timer retries a request, if all retries are used up
 *		it returns a NAK
 */

void
atp_req_timeout(trp)
register struct atp_trans *trp;
{
	int s;
	register gbuf_t *m;
	gref_t *gref;
	struct atp_state *atp;
	struct atp_trans *ctrp;

	if ((atp = trp->tr_queue) == 0)
		return;
	ATDISABLE(s, atp->atp_lock);
	if (atp->atp_flags & ATP_CLOSING) {
		ATENABLE(s, atp->atp_lock);
		return;
	}
	for (ctrp = atp->atp_trans_wait.head; ctrp; ctrp = ctrp->tr_list.next) {
		if (ctrp == trp)
			break;
	}
	if (ctrp != trp) {
		ATENABLE(s, atp->atp_lock);
		return;
	}

	if ((m = gbuf_cont(trp->tr_xmt)) == NULL)
	        m = trp->tr_xmt;               /* issued via the new interface */

	if (trp->tr_retry == 0) {
		trp->tr_state = TRANS_FAILED;
		if (m == trp->tr_xmt) {
			trp->tr_xmt = NULL;
l_notify:
				gbuf_wset(m,1);
				*gbuf_rptr(m) = 99;
				gbuf_set_type(m, MSG_DATA);
				gref = trp->tr_queue->atp_gref;
				ATENABLE(s, atp->atp_lock);
				atalk_putnext(gref, m);

			return;
		}
		dPrintf(D_M_ATP_LOW,D_L_INFO, ("atp_req_timeout: skt=%d\n",
			trp->tr_local_socket));
		m = trp->tr_xmt;
		switch(((ioc_t *)(gbuf_rptr(trp->tr_xmt)))->ioc_cmd) {
		case AT_ATP_ISSUE_REQUEST:
			trp->tr_xmt = NULL;
			if (trp->tr_queue->dflag)
				((ioc_t *)gbuf_rptr(m))->ioc_cmd = AT_ATP_REQUEST_COMPLETE;
			else if (trp->tr_bdsp == NULL) {
				ATENABLE(s, atp->atp_lock);
				gbuf_freem(m);
				if (trp->tr_rsp_wait)
					wakeup(&trp->tr_event);
				break;
			}
			ATENABLE(s, atp->atp_lock);
			atp_iocnak(trp->tr_queue, m, ETIMEDOUT);
			atp_free(trp);
			return;

		case AT_ATP_ISSUE_REQUEST_NOTE:
		case AT_ATP_ISSUE_REQUEST_TICKLE:
			trp->tr_xmt = gbuf_cont(m);
			gbuf_cont(m) = NULL;
			goto l_notify;
		}
	} else {
		(AT_ATP_HDR(m))->bitmap = trp->tr_bitmap;

		if (trp->tr_retry != (unsigned int) ATP_INFINITE_RETRIES)
			trp->tr_retry--;
		ATENABLE(s, atp->atp_lock);
		atp_send(trp);
	}
}


/*
 *	atp_free frees up a request, cleaning up the queues and freeing
 *		the request packet
 *      always called at 'lock'
 */

void atp_free(trp)
register struct atp_trans *trp;
{	
	register struct atp_state *atp;
	register int i;
	int s;
	
	dPrintf(D_M_ATP_LOW, D_L_TRACE,
		("atp_free: freeing trp 0x%x\n", (u_int) trp));

	ATDISABLE(s, atpgen_lock);

	if (trp->tr_state == TRANS_ABORTING) {
		ATP_Q_REMOVE(atp_trans_abort, trp, tr_list);
		trp->tr_state = TRANS_DONE;
	}
	else {
		if (trp->tr_tmo_func)
	        atp_untimout(atp_req_timeout, trp);

		atp = trp->tr_queue;
		ATP_Q_REMOVE(atp->atp_trans_wait, trp, tr_list);
	
		if (trp->tr_xmt) {
		  	gbuf_freem(trp->tr_xmt);
			trp->tr_xmt = NULL;
		}
		for (i = 0; i < 8; i++) {
		        if (trp->tr_rcv[i]) {
			        gbuf_freem(trp->tr_rcv[i]);
				trp->tr_rcv[i] = NULL;
			}
		}
		if (trp->tr_bdsp) {
			gbuf_freem(trp->tr_bdsp);
			trp->tr_bdsp = NULL;
		}
		
		if (trp->tr_rsp_wait) {
			trp->tr_state = TRANS_ABORTING;
			ATP_Q_APPEND(atp_trans_abort, trp, tr_list);
			wakeup(&trp->tr_event);
			ATENABLE(s, atpgen_lock);
			return;
		}
	}
	
	ATENABLE(s, atpgen_lock);
	atp_trans_free(trp);
} /* atp_free */


/*
 *	atp_send transmits a request packet by queuing it (if it isn't already) and
 *		scheduling the queue
 */

void atp_send(trp)
register struct atp_trans *trp;
{
	gbuf_t *m;
	struct atp_state *atp;

	dPrintf(D_M_ATP_LOW, D_L_OUTPUT, ("atp_send: trp=0x%x, loc=%d\n",
		(u_int) trp->tr_queue, trp->tr_local_socket));

	if ((atp = trp->tr_queue) != 0) {
	  if (trp->tr_state == TRANS_TIMEOUT) {
	    if ((m = gbuf_cont(trp->tr_xmt)) == NULL)
	        m = trp->tr_xmt;

	    /*
	     *	Now either release the transaction or start the timer
	     */
	    if (!trp->tr_retry && !trp->tr_bitmap && !trp->tr_xo) {
		m = (gbuf_t *)gbuf_copym(m);
		atp_x_done(trp);
	    } else {
		m = (gbuf_t *)gbuf_dupm(m);

		atp_timout(atp_req_timeout, trp, trp->tr_timeout);
	    }

	    if (m) {	
	        trace_mbufs(D_M_ATP_LOW, "  m", m);
		DDP_OUTPUT(m);
	    }
	}
  }
}


/*
 *	atp_reply sends all the available messages in the bitmap again
 *		by queueing us to the write service routine
 */

void atp_reply(rcbp)
register struct atp_rcb *rcbp;
{
	register struct atp_state *atp;
	register int i;
	int s;

  if ((atp = rcbp->rc_queue) != 0) {
	ATDISABLE(s, atp->atp_lock);
	for (i = 0; i < rcbp->rc_pktcnt; i++) {
		if (rcbp->rc_bitmap&atp_mask[i])
			rcbp->rc_snd[i] = 1;
		else
			rcbp->rc_snd[i] = 0;
	}
        if (rcbp->rc_rep_waiting == 0) {
	        rcbp->rc_state = RCB_SENDING;
	        rcbp->rc_rep_waiting = 1;
	        ATENABLE(s, atp->atp_lock);
	        atp_send_replies(atp, rcbp);
	} else
	ATENABLE(s, atp->atp_lock);
  }
}


/*
 *	The rcb timer just frees the rcb, this happens when we missed a release for XO
 */

void atp_rcb_timer()
{  
	int s;
        register struct atp_rcb *rcbp;
	register struct atp_rcb *next_rcbp;
	extern   struct atp_rcb_qhead atp_need_rel;
	extern struct atp_trans *trp_tmo_rcb;

l_again:
	ATDISABLE(s, atpgen_lock);
	for (rcbp = atp_need_rel.head; rcbp; rcbp = next_rcbp) {
	        next_rcbp = rcbp->rc_tlist.next;

	        if (abs(time.tv_sec - rcbp->rc_timestamp) > 30) {
		        ATENABLE(s, atpgen_lock);
		        atp_rcb_free(rcbp);
		        goto l_again;
		}
	}
	ATENABLE(s, atpgen_lock);
	atp_timout(atp_rcb_timer, trp_tmo_rcb, 10 * HZ);
}

atp_iocack(atp, m)
struct   atp_state *atp;
register gbuf_t *m;
{
	if (gbuf_type(m) == MSG_IOCTL)
		gbuf_set_type(m, MSG_IOCACK);
	if (gbuf_cont(m))
		((ioc_t *)gbuf_rptr(m))->ioc_count = gbuf_msgsize(gbuf_cont(m));
	else
		((ioc_t *)gbuf_rptr(m))->ioc_count = 0;

	if (atp->dflag)
		asp_ack_reply(atp->atp_gref, m);
	else
		atalk_putnext(atp->atp_gref, m);
}

atp_iocnak(atp, m, err)
struct   atp_state *atp;
register gbuf_t *m;
register int err;
{
	if (gbuf_type(m) == MSG_IOCTL)
		gbuf_set_type(m, MSG_IOCNAK);
	((ioc_t *)gbuf_rptr(m))->ioc_count = 0;
	((ioc_t *)gbuf_rptr(m))->ioc_error = err ? err : ENXIO;
	((ioc_t *)gbuf_rptr(m))->ioc_rval = -1;
	if (gbuf_cont(m)) {
		gbuf_freem(gbuf_cont(m));
		gbuf_cont(m) = NULL;
	}

	if (atp->dflag)
		asp_nak_reply(atp->atp_gref, m);
	else
		atalk_putnext(atp->atp_gref, m);
}

/*
 *	Generate a transaction id for a socket
 */
static int lasttid;
atp_tid(atp)
register struct atp_state *atp;
{
	register int i;
	register struct atp_trans *trp;
	int s;

	ATDISABLE(s, atpgen_lock);
	for (i = lasttid;;) {
		i = (i+1)&0xffff;

		for (trp = atp->atp_trans_wait.head; trp; trp = trp->tr_list.next) {
		        if (trp->tr_tid == i)
			        break;
		}
		if (trp == NULL) {
			lasttid = i;
			ATENABLE(s, atpgen_lock);
			return(i);
		}
	}
}
Commit	Line	Data
1c79356b A	1	/*
	2	* Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
	3	*
	4	* @APPLE_LICENSE_HEADER_START@
	5	*
43866e37	6	* Copyright (c) 1999-2003 Apple Computer, Inc. All Rights Reserved.
1c79356b	7	*
43866e37 A	8	* This file contains Original Code and/or Modifications of Original Code
	9	* as defined in and that are subject to the Apple Public Source License
	10	* Version 2.0 (the 'License'). You may not use this file except in
	11	* compliance with the License. Please obtain a copy of the License at
	12	* http://www.opensource.apple.com/apsl/ and read it before using this
	13	* file.
	14	*
	15	* The Original Code and all software distributed under the License are
	16	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
1c79356b A	17	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
1c79356b A	18	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
43866e37 A	19	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	20	* Please see the License for the specific language governing rights and
	21	* limitations under the License.
1c79356b A	22	*
	23	* @APPLE_LICENSE_HEADER_END@
	24	*/
	25	/*
	26	* Copyright (c) 1996-1998 Apple Computer, Inc.
	27	* All Rights Reserved.
	28	*/
	29
	30	/* Modified for MP, 1996 by Tuyen Nguyen
	31	* Modified, March 17, 1997 by Tuyen Nguyen for MacOSX.
	32	*/
	33	#include <sys/errno.h>
	34	#include <sys/types.h>
	35	#include <sys/param.h>
	36	#include <machine/spl.h>
	37	#include <sys/systm.h>
	38	#include <sys/kernel.h>
	39	#include <sys/proc.h>
	40	#include <sys/filedesc.h>
	41	#include <sys/fcntl.h>
	42	#include <sys/mbuf.h>
	43	#include <sys/ioctl.h>
	44	#include <sys/malloc.h>
	45	#include <sys/socket.h>
	46
	47	#include <netat/sysglue.h>
	48	#include <netat/appletalk.h>
	49	#include <netat/ddp.h>
	50	#include <netat/at_pcb.h>
	51	#include <netat/atp.h>
	52	#include <netat/debug.h>
	53
	54	extern atlock_t atpgen_lock;
	55	void atp_free();
	56	void atp_send(struct atp_trans *);
	57
	58	/*
	59	* The request timer retries a request, if all retries are used up
	60	* it returns a NAK
	61	*/
	62
	63	void
	64	atp_req_timeout(trp)
	65	register struct atp_trans *trp;
	66	{
	67	int s;
	68	register gbuf_t *m;
	69	gref_t *gref;
	70	struct atp_state *atp;
	71	struct atp_trans *ctrp;
	72
	73	if ((atp = trp->tr_queue) == 0)
	74	return;
	75	ATDISABLE(s, atp->atp_lock);
	76	if (atp->atp_flags & ATP_CLOSING) {
	77	ATENABLE(s, atp->atp_lock);
	78	return;
	79	}
	80	for (ctrp = atp->atp_trans_wait.head; ctrp; ctrp = ctrp->tr_list.next) {
	81	if (ctrp == trp)
	82	break;
	83	}
	84	if (ctrp != trp) {
	85	ATENABLE(s, atp->atp_lock);
86	return;
87	}
88
89	if ((m = gbuf_cont(trp->tr_xmt)) == NULL)
90	m = trp->tr_xmt; /* issued via the new interface */
91
92	if (trp->tr_retry == 0) {
93	trp->tr_state = TRANS_FAILED;
94	if (m == trp->tr_xmt) {
95	trp->tr_xmt = NULL;
96	l_notify:
97	gbuf_wset(m,1);
98	*gbuf_rptr(m) = 99;
99	gbuf_set_type(m, MSG_DATA);
100	gref = trp->tr_queue->atp_gref;
101	ATENABLE(s, atp->atp_lock);
102	atalk_putnext(gref, m);
103
104	return;
105	}
106	dPrintf(D_M_ATP_LOW,D_L_INFO, ("atp_req_timeout: skt=%d\n",
107	trp->tr_local_socket));
108	m = trp->tr_xmt;
109	switch(((ioc_t *)(gbuf_rptr(trp->tr_xmt)))->ioc_cmd) {
110	case AT_ATP_ISSUE_REQUEST:
111	trp->tr_xmt = NULL;
112	if (trp->tr_queue->dflag)
113	((ioc_t *)gbuf_rptr(m))->ioc_cmd = AT_ATP_REQUEST_COMPLETE;
114	else if (trp->tr_bdsp == NULL) {
115	ATENABLE(s, atp->atp_lock);
116	gbuf_freem(m);
117	if (trp->tr_rsp_wait)
9bccf70c	118	wakeup(&trp->tr_event);
1c79356b A	119	break;
	120	}
	121	ATENABLE(s, atp->atp_lock);
	122	atp_iocnak(trp->tr_queue, m, ETIMEDOUT);
	123	atp_free(trp);
	124	return;
	125
	126	case AT_ATP_ISSUE_REQUEST_NOTE:
	127	case AT_ATP_ISSUE_REQUEST_TICKLE:
	128	trp->tr_xmt = gbuf_cont(m);
	129	gbuf_cont(m) = NULL;
	130	goto l_notify;
	131	}
	132	} else {
	133	(AT_ATP_HDR(m))->bitmap = trp->tr_bitmap;
	134
	135	if (trp->tr_retry != (unsigned int) ATP_INFINITE_RETRIES)
	136	trp->tr_retry--;
	137	ATENABLE(s, atp->atp_lock);
	138	atp_send(trp);
	139	}
	140	}
	141
	142
	143	/*
	144	* atp_free frees up a request, cleaning up the queues and freeing
	145	* the request packet
	146	* always called at 'lock'
	147	*/
	148
	149	void atp_free(trp)
	150	register struct atp_trans *trp;
0b4e3aa0	151	{
1c79356b A	152	register struct atp_state *atp;
	153	register int i;
	154	int s;
	155
	156	dPrintf(D_M_ATP_LOW, D_L_TRACE,
	157	("atp_free: freeing trp 0x%x\n", (u_int) trp));
1c79356b	158
0b4e3aa0	159	ATDISABLE(s, atpgen_lock);
1c79356b	160
0b4e3aa0 A	161	if (trp->tr_state == TRANS_ABORTING) {
	162	ATP_Q_REMOVE(atp_trans_abort, trp, tr_list);
	163	trp->tr_state = TRANS_DONE;
1c79356b	164	}
0b4e3aa0 A	165	else {
	166	if (trp->tr_tmo_func)
	167	atp_untimout(atp_req_timeout, trp);
	168
	169	atp = trp->tr_queue;
	170	ATP_Q_REMOVE(atp->atp_trans_wait, trp, tr_list);
	171
	172	if (trp->tr_xmt) {
	173	gbuf_freem(trp->tr_xmt);
	174	trp->tr_xmt = NULL;
	175	}
	176	for (i = 0; i < 8; i++) {
	177	if (trp->tr_rcv[i]) {
	178	gbuf_freem(trp->tr_rcv[i]);
	179	trp->tr_rcv[i] = NULL;
	180	}
	181	}
	182	if (trp->tr_bdsp) {
	183	gbuf_freem(trp->tr_bdsp);
	184	trp->tr_bdsp = NULL;
	185	}
	186
	187	if (trp->tr_rsp_wait) {
	188	trp->tr_state = TRANS_ABORTING;
	189	ATP_Q_APPEND(atp_trans_abort, trp, tr_list);
9bccf70c	190	wakeup(&trp->tr_event);
0b4e3aa0 A	191	ATENABLE(s, atpgen_lock);
0b4e3aa0 A	192	return;
1c79356b A	193	}
1c79356b A	194	}
0b4e3aa0	195
1c79356b A	196	ATENABLE(s, atpgen_lock);
1c79356b A	197	atp_trans_free(trp);
1c79356b A	198	} /* atp_free */
	199
	200
	201	/*
	202	* atp_send transmits a request packet by queuing it (if it isn't already) and
	203	* scheduling the queue
	204	*/
	205
	206	void atp_send(trp)
	207	register struct atp_trans *trp;
	208	{
	209	gbuf_t *m;
	210	struct atp_state *atp;
	211
	212	dPrintf(D_M_ATP_LOW, D_L_OUTPUT, ("atp_send: trp=0x%x, loc=%d\n",
	213	(u_int) trp->tr_queue, trp->tr_local_socket));
	214
	215	if ((atp = trp->tr_queue) != 0) {
	216	if (trp->tr_state == TRANS_TIMEOUT) {
	217	if ((m = gbuf_cont(trp->tr_xmt)) == NULL)
	218	m = trp->tr_xmt;
	219
	220	/*
	221	* Now either release the transaction or start the timer
	222	*/
	223	if (!trp->tr_retry && !trp->tr_bitmap && !trp->tr_xo) {
	224	m = (gbuf_t *)gbuf_copym(m);
	225	atp_x_done(trp);
	226	} else {
	227	m = (gbuf_t *)gbuf_dupm(m);
	228
	229	atp_timout(atp_req_timeout, trp, trp->tr_timeout);
	230	}
	231
	232	if (m) {
	233	trace_mbufs(D_M_ATP_LOW, " m", m);
	234	DDP_OUTPUT(m);
	235	}
	236	}
	237	}
	238	}
	239
	240
	241	/*
	242	* atp_reply sends all the available messages in the bitmap again
	243	* by queueing us to the write service routine
	244	*/
	245
	246	void atp_reply(rcbp)
	247	register struct atp_rcb *rcbp;
	248	{
	249	register struct atp_state *atp;
	250	register int i;
	251	int s;
	252
	253	if ((atp = rcbp->rc_queue) != 0) {
	254	ATDISABLE(s, atp->atp_lock);
	255	for (i = 0; i < rcbp->rc_pktcnt; i++) {
	256	if (rcbp->rc_bitmap&atp_mask[i])
	257	rcbp->rc_snd[i] = 1;
	258	else
	259	rcbp->rc_snd[i] = 0;
	260	}
	261	if (rcbp->rc_rep_waiting == 0) {
262	rcbp->rc_state = RCB_SENDING;
263	rcbp->rc_rep_waiting = 1;
264	ATENABLE(s, atp->atp_lock);
265	atp_send_replies(atp, rcbp);
266	} else
267	ATENABLE(s, atp->atp_lock);
268	}
269	}
270
271
272	/*
273	* The rcb timer just frees the rcb, this happens when we missed a release for XO
274	*/
275
276	void atp_rcb_timer()
277	{
278	int s;
279	register struct atp_rcb *rcbp;
280	register struct atp_rcb *next_rcbp;
281	extern struct atp_rcb_qhead atp_need_rel;
282	extern struct atp_trans *trp_tmo_rcb;
283
284	l_again:
285	ATDISABLE(s, atpgen_lock);
286	for (rcbp = atp_need_rel.head; rcbp; rcbp = next_rcbp) {
287	next_rcbp = rcbp->rc_tlist.next;
288
289	if (abs(time.tv_sec - rcbp->rc_timestamp) > 30) {
290	ATENABLE(s, atpgen_lock);
291	atp_rcb_free(rcbp);
292	goto l_again;
293	}
294	}
295	ATENABLE(s, atpgen_lock);
296	atp_timout(atp_rcb_timer, trp_tmo_rcb, 10 * HZ);
297	}
298
299	atp_iocack(atp, m)
300	struct atp_state *atp;
301	register gbuf_t *m;
302	{
303	if (gbuf_type(m) == MSG_IOCTL)
304	gbuf_set_type(m, MSG_IOCACK);
305	if (gbuf_cont(m))
306	((ioc_t *)gbuf_rptr(m))->ioc_count = gbuf_msgsize(gbuf_cont(m));
307	else
308	((ioc_t *)gbuf_rptr(m))->ioc_count = 0;
309
310	if (atp->dflag)
311	asp_ack_reply(atp->atp_gref, m);
312	else
313	atalk_putnext(atp->atp_gref, m);
314	}
315
316	atp_iocnak(atp, m, err)
317	struct atp_state *atp;
318	register gbuf_t *m;
319	register int err;
320	{
321	if (gbuf_type(m) == MSG_IOCTL)
322	gbuf_set_type(m, MSG_IOCNAK);
323	((ioc_t *)gbuf_rptr(m))->ioc_count = 0;
324	((ioc_t *)gbuf_rptr(m))->ioc_error = err ? err : ENXIO;
325	((ioc_t *)gbuf_rptr(m))->ioc_rval = -1;
326	if (gbuf_cont(m)) {
327	gbuf_freem(gbuf_cont(m));
328	gbuf_cont(m) = NULL;
329	}
330
331	if (atp->dflag)
332	asp_nak_reply(atp->atp_gref, m);
333	else
334	atalk_putnext(atp->atp_gref, m);
335	}
336
337	/*
338	* Generate a transaction id for a socket
339	*/
340	static int lasttid;
341	atp_tid(atp)
342	register struct atp_state *atp;
343	{
344	register int i;
345	register struct atp_trans *trp;
346	int s;
347
348	ATDISABLE(s, atpgen_lock);
349	for (i = lasttid;;) {
350	i = (i+1)&0xffff;
351
352	for (trp = atp->atp_trans_wait.head; trp; trp = trp->tr_list.next) {
353	if (trp->tr_tid == i)
354	break;
355	}
356	if (trp == NULL) {
357	lasttid = i;
358	ATENABLE(s, atpgen_lock);
359	return(i);
360	}
361	}
362	}