4 * This code REQUIRES 2.1.15 or higher/ NET3.038
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.
13 * LAPB 001 Jonathan Naylor Started Coding
14 * LAPB 002 Jonathan Naylor New timer architecture.
17 #include <linux/errno.h>
18 #include <linux/types.h>
19 #include <linux/socket.h>
21 #include <linux/kernel.h>
22 #include <linux/sched.h>
23 #include <linux/timer.h>
24 #include <linux/string.h>
25 #include <linux/sockios.h>
26 #include <linux/net.h>
27 #include <linux/inet.h>
28 #include <linux/skbuff.h>
30 #include <asm/uaccess.h>
31 #include <asm/system.h>
32 #include <linux/fcntl.h>
34 #include <linux/interrupt.h>
38 * This procedure is passed a buffer descriptor for an iframe. It builds
39 * the rest of the control part of the frame and then writes it out.
41 static void lapb_send_iframe(lapb_cb *lapb, struct sk_buff *skb, int poll_bit)
48 if (lapb->mode & LAPB_EXTENDED) {
49 frame = skb_push(skb, 2);
52 frame[0] |= (lapb->vs << 1);
53 frame[1] = (poll_bit) ? LAPB_EPF : 0;
54 frame[1] |= (lapb->vr << 1);
56 frame = skb_push(skb, 1);
59 *frame |= (poll_bit) ? LAPB_SPF : 0;
60 *frame |= (lapb->vr << 5);
61 *frame |= (lapb->vs << 1);
65 printk(KERN_DEBUG "lapb: (%p) S%d TX I(%d) S%d R%d\n", lapb->token, lapb->state, poll_bit, lapb->vs, lapb->vr);
68 lapb_transmit_buffer(lapb, skb, LAPB_COMMAND);
71 void lapb_kick(lapb_cb *lapb)
73 struct sk_buff *skb, *skbn;
74 unsigned short modulus, start, end;
76 modulus = (lapb->mode & LAPB_EXTENDED) ? LAPB_EMODULUS : LAPB_SMODULUS;
78 start = (skb_peek(&lapb->ack_queue) == NULL) ? lapb->va : lapb->vs;
79 end = (lapb->va + lapb->window) % modulus;
81 if (!(lapb->condition & LAPB_PEER_RX_BUSY_CONDITION) &&
83 skb_peek(&lapb->write_queue) != NULL) {
88 * Dequeue the frame and copy it.
90 skb = skb_dequeue(&lapb->write_queue);
93 if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) {
94 skb_queue_head(&lapb->write_queue, skb);
99 skb_set_owner_w(skbn, skb->sk);
102 * Transmit the frame copy.
104 lapb_send_iframe(lapb, skbn, LAPB_POLLOFF);
106 lapb->vs = (lapb->vs + 1) % modulus;
109 * Requeue the original data frame.
111 skb_queue_tail(&lapb->ack_queue, skb);
113 } while (lapb->vs != end && (skb = skb_dequeue(&lapb->write_queue)) != NULL);
115 lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
117 if (!lapb_t1timer_running(lapb))
118 lapb_start_t1timer(lapb);
122 void lapb_transmit_buffer(lapb_cb *lapb, struct sk_buff *skb, int type)
126 ptr = skb_push(skb, 1);
128 if (lapb->mode & LAPB_MLP) {
129 if (lapb->mode & LAPB_DCE) {
130 if (type == LAPB_COMMAND)
132 if (type == LAPB_RESPONSE)
135 if (type == LAPB_COMMAND)
137 if (type == LAPB_RESPONSE)
141 if (lapb->mode & LAPB_DCE) {
142 if (type == LAPB_COMMAND)
144 if (type == LAPB_RESPONSE)
147 if (type == LAPB_COMMAND)
149 if (type == LAPB_RESPONSE)
155 printk(KERN_DEBUG "lapb: (%p) S%d TX %02X %02X %02X\n", lapb->token, lapb->state, skb->data[0], skb->data[1], skb->data[2]);
158 if (!lapb_data_transmit(lapb, skb))
162 void lapb_establish_data_link(lapb_cb *lapb)
164 lapb->condition = 0x00;
167 if (lapb->mode & LAPB_EXTENDED) {
169 printk(KERN_DEBUG "lapb: (%p) S%d TX SABME(1)\n", lapb->token, lapb->state);
171 lapb_send_control(lapb, LAPB_SABME, LAPB_POLLON, LAPB_COMMAND);
174 printk(KERN_DEBUG "lapb: (%p) S%d TX SABM(1)\n", lapb->token, lapb->state);
176 lapb_send_control(lapb, LAPB_SABM, LAPB_POLLON, LAPB_COMMAND);
179 lapb_start_t1timer(lapb);
180 lapb_stop_t2timer(lapb);
183 void lapb_enquiry_response(lapb_cb *lapb)
186 printk(KERN_DEBUG "lapb: (%p) S%d TX RR(1) R%d\n", lapb->token, lapb->state, lapb->vr);
189 lapb_send_control(lapb, LAPB_RR, LAPB_POLLON, LAPB_RESPONSE);
191 lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
194 void lapb_timeout_response(lapb_cb *lapb)
197 printk(KERN_DEBUG "lapb: (%p) S%d TX RR(0) R%d\n", lapb->token, lapb->state, lapb->vr);
200 lapb_send_control(lapb, LAPB_RR, LAPB_POLLOFF, LAPB_RESPONSE);
202 lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
205 void lapb_check_iframes_acked(lapb_cb *lapb, unsigned short nr)
207 if (lapb->vs == nr) {
208 lapb_frames_acked(lapb, nr);
209 lapb_stop_t1timer(lapb);
212 if (lapb->va != nr) {
213 lapb_frames_acked(lapb, nr);
214 lapb_start_t1timer(lapb);
219 void lapb_check_need_response(lapb_cb *lapb, int type, int pf)
221 if (type == LAPB_COMMAND && pf)
222 lapb_enquiry_response(lapb);