[linux.git] / net / lapb / lapb_out.c

/*
 *	LAPB release 002
 *
 *	This code REQUIRES 2.1.15 or higher/ NET3.038
 *
 *	This module:
 *		This module is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 *
 *	History
 *	LAPB 001	Jonathan Naylor	Started Coding
 *	LAPB 002	Jonathan Naylor	New timer architecture.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/inet.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <net/sock.h>
#include <linux/uaccess.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <net/lapb.h>

/*
 *  This procedure is passed a buffer descriptor for an iframe. It builds
 *  the rest of the control part of the frame and then writes it out.
 */
static void lapb_send_iframe(struct lapb_cb *lapb, struct sk_buff *skb, int poll_bit)
{
	unsigned char *frame;

	if (!skb)
		return;

	if (lapb->mode & LAPB_EXTENDED) {
		frame = skb_push(skb, 2);

		frame[0] = LAPB_I;
		frame[0] |= lapb->vs << 1;
		frame[1] = poll_bit ? LAPB_EPF : 0;
		frame[1] |= lapb->vr << 1;
	} else {
		frame = skb_push(skb, 1);

		*frame = LAPB_I;
		*frame |= poll_bit ? LAPB_SPF : 0;
		*frame |= lapb->vr << 5;
		*frame |= lapb->vs << 1;
	}

	lapb_dbg(1, "(%p) S%d TX I(%d) S%d R%d\n",
		 lapb->dev, lapb->state, poll_bit, lapb->vs, lapb->vr);

	lapb_transmit_buffer(lapb, skb, LAPB_COMMAND);
}

void lapb_kick(struct lapb_cb *lapb)
{
	struct sk_buff *skb, *skbn;
	unsigned short modulus, start, end;

	modulus = (lapb->mode & LAPB_EXTENDED) ? LAPB_EMODULUS : LAPB_SMODULUS;
	start = !skb_peek(&lapb->ack_queue) ? lapb->va : lapb->vs;
	end   = (lapb->va + lapb->window) % modulus;

	if (!(lapb->condition & LAPB_PEER_RX_BUSY_CONDITION) &&
	    start != end && skb_peek(&lapb->write_queue)) {
		lapb->vs = start;

		/*
		 * Dequeue the frame and copy it.
		 */
		skb = skb_dequeue(&lapb->write_queue);

		do {
			if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) {
				skb_queue_head(&lapb->write_queue, skb);
				break;
			}

			if (skb->sk)
				skb_set_owner_w(skbn, skb->sk);

			/*
			 * Transmit the frame copy.
			 */
			lapb_send_iframe(lapb, skbn, LAPB_POLLOFF);

			lapb->vs = (lapb->vs + 1) % modulus;

			/*
			 * Requeue the original data frame.
			 */
			skb_queue_tail(&lapb->ack_queue, skb);

		} while (lapb->vs != end && (skb = skb_dequeue(&lapb->write_queue)) != NULL);

		lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;

		if (!lapb_t1timer_running(lapb))
			lapb_start_t1timer(lapb);
	}
}

void lapb_transmit_buffer(struct lapb_cb *lapb, struct sk_buff *skb, int type)
{
	unsigned char *ptr;

	ptr = skb_push(skb, 1);

	if (lapb->mode & LAPB_MLP) {
		if (lapb->mode & LAPB_DCE) {
			if (type == LAPB_COMMAND)
				*ptr = LAPB_ADDR_C;
			if (type == LAPB_RESPONSE)
				*ptr = LAPB_ADDR_D;
		} else {
			if (type == LAPB_COMMAND)
				*ptr = LAPB_ADDR_D;
			if (type == LAPB_RESPONSE)
				*ptr = LAPB_ADDR_C;
		}
	} else {
		if (lapb->mode & LAPB_DCE) {
			if (type == LAPB_COMMAND)
				*ptr = LAPB_ADDR_A;
			if (type == LAPB_RESPONSE)
				*ptr = LAPB_ADDR_B;
		} else {
			if (type == LAPB_COMMAND)
				*ptr = LAPB_ADDR_B;
			if (type == LAPB_RESPONSE)
				*ptr = LAPB_ADDR_A;
		}
	}

	lapb_dbg(2, "(%p) S%d TX %3ph\n", lapb->dev, lapb->state, skb->data);

	if (!lapb_data_transmit(lapb, skb))
		kfree_skb(skb);
}

void lapb_establish_data_link(struct lapb_cb *lapb)
{
	lapb->condition = 0x00;
	lapb->n2count   = 0;

	if (lapb->mode & LAPB_EXTENDED) {
		lapb_dbg(1, "(%p) S%d TX SABME(1)\n", lapb->dev, lapb->state);
		lapb_send_control(lapb, LAPB_SABME, LAPB_POLLON, LAPB_COMMAND);
	} else {
		lapb_dbg(1, "(%p) S%d TX SABM(1)\n", lapb->dev, lapb->state);
		lapb_send_control(lapb, LAPB_SABM, LAPB_POLLON, LAPB_COMMAND);
	}

	lapb_start_t1timer(lapb);
	lapb_stop_t2timer(lapb);
}

void lapb_enquiry_response(struct lapb_cb *lapb)
{
	lapb_dbg(1, "(%p) S%d TX RR(1) R%d\n",
		 lapb->dev, lapb->state, lapb->vr);

	lapb_send_control(lapb, LAPB_RR, LAPB_POLLON, LAPB_RESPONSE);

	lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
}

void lapb_timeout_response(struct lapb_cb *lapb)
{
	lapb_dbg(1, "(%p) S%d TX RR(0) R%d\n",
		 lapb->dev, lapb->state, lapb->vr);
	lapb_send_control(lapb, LAPB_RR, LAPB_POLLOFF, LAPB_RESPONSE);

	lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
}

void lapb_check_iframes_acked(struct lapb_cb *lapb, unsigned short nr)
{
	if (lapb->vs == nr) {
		lapb_frames_acked(lapb, nr);
		lapb_stop_t1timer(lapb);
		lapb->n2count = 0;
	} else if (lapb->va != nr) {
		lapb_frames_acked(lapb, nr);
		lapb_start_t1timer(lapb);
	}
}

void lapb_check_need_response(struct lapb_cb *lapb, int type, int pf)
{
	if (type == LAPB_COMMAND && pf)
		lapb_enquiry_response(lapb);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* LAPB release 002
	3	*
	4	* This code REQUIRES 2.1.15 or higher/ NET3.038
	5	*
	6	* This module:
	7	* This module is free software; you can redistribute it and/or
	8	* modify it under the terms of the GNU General Public License
	9	* as published by the Free Software Foundation; either version
	10	* 2 of the License, or (at your option) any later version.
	11	*
	12	* History
	13	* LAPB 001 Jonathan Naylor Started Coding
	14	* LAPB 002 Jonathan Naylor New timer architecture.
	15	*/
	16
a508da6c JP	17	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
a508da6c JP	18
1da177e4 LT	19	#include <linux/errno.h>
	20	#include <linux/types.h>
	21	#include <linux/socket.h>
	22	#include <linux/in.h>
	23	#include <linux/kernel.h>
1da177e4 LT	24	#include <linux/timer.h>
	25	#include <linux/string.h>
	26	#include <linux/sockios.h>
	27	#include <linux/net.h>
	28	#include <linux/inet.h>
	29	#include <linux/skbuff.h>
5a0e3ad6	30	#include <linux/slab.h>
1da177e4	31	#include <net/sock.h>
7c0f6ba6	32	#include <linux/uaccess.h>
1da177e4 LT	33	#include <linux/fcntl.h>
	34	#include <linux/mm.h>
	35	#include <linux/interrupt.h>
	36	#include <net/lapb.h>
	37
56d6c3d7	38	/*
1da177e4 LT	39	* This procedure is passed a buffer descriptor for an iframe. It builds
	40	* the rest of the control part of the frame and then writes it out.
	41	*/
	42	static void lapb_send_iframe(struct lapb_cb lapb, struct sk_buff skb, int poll_bit)
	43	{
	44	unsigned char *frame;
	45
	46	if (!skb)
	47	return;
	48
	49	if (lapb->mode & LAPB_EXTENDED) {
	50	frame = skb_push(skb, 2);
	51
	52	frame[0] = LAPB_I;
	53	frame[0] \|= lapb->vs << 1;
	54	frame[1] = poll_bit ? LAPB_EPF : 0;
	55	frame[1] \|= lapb->vr << 1;
	56	} else {
	57	frame = skb_push(skb, 1);
	58
	59	*frame = LAPB_I;
	60	*frame \|= poll_bit ? LAPB_SPF : 0;
	61	*frame \|= lapb->vr << 5;
	62	*frame \|= lapb->vs << 1;
	63	}
	64
a508da6c JP	65	lapb_dbg(1, "(%p) S%d TX I(%d) S%d R%d\n",
a508da6c JP	66	lapb->dev, lapb->state, poll_bit, lapb->vs, lapb->vr);
1da177e4	67
56d6c3d7	68	lapb_transmit_buffer(lapb, skb, LAPB_COMMAND);
1da177e4 LT	69	}
	70
	71	void lapb_kick(struct lapb_cb *lapb)
	72	{
	73	struct sk_buff skb, skbn;
	74	unsigned short modulus, start, end;
	75
	76	modulus = (lapb->mode & LAPB_EXTENDED) ? LAPB_EMODULUS : LAPB_SMODULUS;
	77	start = !skb_peek(&lapb->ack_queue) ? lapb->va : lapb->vs;
	78	end = (lapb->va + lapb->window) % modulus;
	79
	80	if (!(lapb->condition & LAPB_PEER_RX_BUSY_CONDITION) &&
	81	start != end && skb_peek(&lapb->write_queue)) {
	82	lapb->vs = start;
	83
	84	/*
	85	* Dequeue the frame and copy it.
	86	*/
	87	skb = skb_dequeue(&lapb->write_queue);
	88
	89	do {
	90	if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) {
	91	skb_queue_head(&lapb->write_queue, skb);
	92	break;
	93	}
	94
	95	if (skb->sk)
	96	skb_set_owner_w(skbn, skb->sk);
	97
	98	/*
	99	* Transmit the frame copy.
	100	*/
	101	lapb_send_iframe(lapb, skbn, LAPB_POLLOFF);
	102
	103	lapb->vs = (lapb->vs + 1) % modulus;
	104
	105	/*
	106	* Requeue the original data frame.
	107	*/
	108	skb_queue_tail(&lapb->ack_queue, skb);
	109
	110	} while (lapb->vs != end && (skb = skb_dequeue(&lapb->write_queue)) != NULL);
	111
	112	lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
	113
	114	if (!lapb_t1timer_running(lapb))
	115	lapb_start_t1timer(lapb);
	116	}
	117	}
	118
	119	void lapb_transmit_buffer(struct lapb_cb lapb, struct sk_buff skb, int type)
	120	{
	121	unsigned char *ptr;
	122
	123	ptr = skb_push(skb, 1);
	124
	125	if (lapb->mode & LAPB_MLP) {
	126	if (lapb->mode & LAPB_DCE) {
	127	if (type == LAPB_COMMAND)
	128	*ptr = LAPB_ADDR_C;
	129	if (type == LAPB_RESPONSE)
	130	*ptr = LAPB_ADDR_D;
	131	} else {
	132	if (type == LAPB_COMMAND)
133	*ptr = LAPB_ADDR_D;
134	if (type == LAPB_RESPONSE)
135	*ptr = LAPB_ADDR_C;
136	}
137	} else {
138	if (lapb->mode & LAPB_DCE) {
139	if (type == LAPB_COMMAND)
140	*ptr = LAPB_ADDR_A;
141	if (type == LAPB_RESPONSE)
142	*ptr = LAPB_ADDR_B;
143	} else {
144	if (type == LAPB_COMMAND)
145	*ptr = LAPB_ADDR_B;
146	if (type == LAPB_RESPONSE)
147	*ptr = LAPB_ADDR_A;
148	}
149	}
150
0d08df6c	151	lapb_dbg(2, "(%p) S%d TX %3ph\n", lapb->dev, lapb->state, skb->data);
1da177e4 LT	152
	153	if (!lapb_data_transmit(lapb, skb))
	154	kfree_skb(skb);
	155	}
	156
	157	void lapb_establish_data_link(struct lapb_cb *lapb)
	158	{
	159	lapb->condition = 0x00;
	160	lapb->n2count = 0;
	161
	162	if (lapb->mode & LAPB_EXTENDED) {
a508da6c	163	lapb_dbg(1, "(%p) S%d TX SABME(1)\n", lapb->dev, lapb->state);
1da177e4 LT	164	lapb_send_control(lapb, LAPB_SABME, LAPB_POLLON, LAPB_COMMAND);
1da177e4 LT	165	} else {
a508da6c	166	lapb_dbg(1, "(%p) S%d TX SABM(1)\n", lapb->dev, lapb->state);
1da177e4 LT	167	lapb_send_control(lapb, LAPB_SABM, LAPB_POLLON, LAPB_COMMAND);
	168	}
	169
	170	lapb_start_t1timer(lapb);
	171	lapb_stop_t2timer(lapb);
	172	}
	173
	174	void lapb_enquiry_response(struct lapb_cb *lapb)
	175	{
a508da6c JP	176	lapb_dbg(1, "(%p) S%d TX RR(1) R%d\n",
a508da6c JP	177	lapb->dev, lapb->state, lapb->vr);
1da177e4 LT	178
	179	lapb_send_control(lapb, LAPB_RR, LAPB_POLLON, LAPB_RESPONSE);
	180
	181	lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
	182	}
	183
	184	void lapb_timeout_response(struct lapb_cb *lapb)
	185	{
a508da6c JP	186	lapb_dbg(1, "(%p) S%d TX RR(0) R%d\n",
a508da6c JP	187	lapb->dev, lapb->state, lapb->vr);
1da177e4 LT	188	lapb_send_control(lapb, LAPB_RR, LAPB_POLLOFF, LAPB_RESPONSE);
	189
	190	lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
	191	}
	192
	193	void lapb_check_iframes_acked(struct lapb_cb *lapb, unsigned short nr)
	194	{
	195	if (lapb->vs == nr) {
	196	lapb_frames_acked(lapb, nr);
	197	lapb_stop_t1timer(lapb);
	198	lapb->n2count = 0;
	199	} else if (lapb->va != nr) {
	200	lapb_frames_acked(lapb, nr);
	201	lapb_start_t1timer(lapb);
	202	}
	203	}
	204
	205	void lapb_check_need_response(struct lapb_cb *lapb, int type, int pf)
	206	{
	207	if (type == LAPB_COMMAND && pf)
	208	lapb_enquiry_response(lapb);
	209	}