ipv6: updates to privacy addresses per RFC 4941
[linux-2.6.git] / net / lapb / lapb_out.c
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
17 #include <linux/errno.h>
18 #include <linux/types.h>
19 #include <linux/socket.h>
20 #include <linux/in.h>
21 #include <linux/kernel.h>
22 #include <linux/timer.h>
23 #include <linux/string.h>
24 #include <linux/sockios.h>
25 #include <linux/net.h>
26 #include <linux/inet.h>
27 #include <linux/skbuff.h>
28 #include <linux/slab.h>
29 #include <net/sock.h>
30 #include <asm/uaccess.h>
31 #include <asm/system.h>
32 #include <linux/fcntl.h>
33 #include <linux/mm.h>
34 #include <linux/interrupt.h>
35 #include <net/lapb.h>
36
37 /*
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.
40  */
41 static void lapb_send_iframe(struct lapb_cb *lapb, struct sk_buff *skb, int poll_bit)
42 {
43         unsigned char *frame;
44
45         if (!skb)
46                 return;
47
48         if (lapb->mode & LAPB_EXTENDED) {
49                 frame = skb_push(skb, 2);
50
51                 frame[0] = LAPB_I;
52                 frame[0] |= lapb->vs << 1;
53                 frame[1] = poll_bit ? LAPB_EPF : 0;
54                 frame[1] |= lapb->vr << 1;
55         } else {
56                 frame = skb_push(skb, 1);
57
58                 *frame = LAPB_I;
59                 *frame |= poll_bit ? LAPB_SPF : 0;
60                 *frame |= lapb->vr << 5;
61                 *frame |= lapb->vs << 1;
62         }
63
64 #if LAPB_DEBUG > 1
65         printk(KERN_DEBUG "lapb: (%p) S%d TX I(%d) S%d R%d\n",
66                lapb->dev, lapb->state, poll_bit, lapb->vs, lapb->vr);
67 #endif
68
69         lapb_transmit_buffer(lapb, skb, LAPB_COMMAND);
70 }
71
72 void lapb_kick(struct lapb_cb *lapb)
73 {
74         struct sk_buff *skb, *skbn;
75         unsigned short modulus, start, end;
76
77         modulus = (lapb->mode & LAPB_EXTENDED) ? LAPB_EMODULUS : LAPB_SMODULUS;
78         start = !skb_peek(&lapb->ack_queue) ? lapb->va : lapb->vs;
79         end   = (lapb->va + lapb->window) % modulus;
80
81         if (!(lapb->condition & LAPB_PEER_RX_BUSY_CONDITION) &&
82             start != end && skb_peek(&lapb->write_queue)) {
83                 lapb->vs = start;
84
85                 /*
86                  * Dequeue the frame and copy it.
87                  */
88                 skb = skb_dequeue(&lapb->write_queue);
89
90                 do {
91                         if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) {
92                                 skb_queue_head(&lapb->write_queue, skb);
93                                 break;
94                         }
95
96                         if (skb->sk)
97                                 skb_set_owner_w(skbn, skb->sk);
98
99                         /*
100                          * Transmit the frame copy.
101                          */
102                         lapb_send_iframe(lapb, skbn, LAPB_POLLOFF);
103
104                         lapb->vs = (lapb->vs + 1) % modulus;
105
106                         /*
107                          * Requeue the original data frame.
108                          */
109                         skb_queue_tail(&lapb->ack_queue, skb);
110
111                 } while (lapb->vs != end && (skb = skb_dequeue(&lapb->write_queue)) != NULL);
112
113                 lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
114
115                 if (!lapb_t1timer_running(lapb))
116                         lapb_start_t1timer(lapb);
117         }
118 }
119
120 void lapb_transmit_buffer(struct lapb_cb *lapb, struct sk_buff *skb, int type)
121 {
122         unsigned char *ptr;
123
124         ptr = skb_push(skb, 1);
125
126         if (lapb->mode & LAPB_MLP) {
127                 if (lapb->mode & LAPB_DCE) {
128                         if (type == LAPB_COMMAND)
129                                 *ptr = LAPB_ADDR_C;
130                         if (type == LAPB_RESPONSE)
131                                 *ptr = LAPB_ADDR_D;
132                 } else {
133                         if (type == LAPB_COMMAND)
134                                 *ptr = LAPB_ADDR_D;
135                         if (type == LAPB_RESPONSE)
136                                 *ptr = LAPB_ADDR_C;
137                 }
138         } else {
139                 if (lapb->mode & LAPB_DCE) {
140                         if (type == LAPB_COMMAND)
141                                 *ptr = LAPB_ADDR_A;
142                         if (type == LAPB_RESPONSE)
143                                 *ptr = LAPB_ADDR_B;
144                 } else {
145                         if (type == LAPB_COMMAND)
146                                 *ptr = LAPB_ADDR_B;
147                         if (type == LAPB_RESPONSE)
148                                 *ptr = LAPB_ADDR_A;
149                 }
150         }
151
152 #if LAPB_DEBUG > 2
153         printk(KERN_DEBUG "lapb: (%p) S%d TX %02X %02X %02X\n",
154                lapb->dev, lapb->state,
155                skb->data[0], skb->data[1], skb->data[2]);
156 #endif
157
158         if (!lapb_data_transmit(lapb, skb))
159                 kfree_skb(skb);
160 }
161
162 void lapb_establish_data_link(struct lapb_cb *lapb)
163 {
164         lapb->condition = 0x00;
165         lapb->n2count   = 0;
166
167         if (lapb->mode & LAPB_EXTENDED) {
168 #if LAPB_DEBUG > 1
169                 printk(KERN_DEBUG "lapb: (%p) S%d TX SABME(1)\n",
170                        lapb->dev, lapb->state);
171 #endif
172                 lapb_send_control(lapb, LAPB_SABME, LAPB_POLLON, LAPB_COMMAND);
173         } else {
174 #if LAPB_DEBUG > 1
175                 printk(KERN_DEBUG "lapb: (%p) S%d TX SABM(1)\n",
176                        lapb->dev, lapb->state);
177 #endif
178                 lapb_send_control(lapb, LAPB_SABM, LAPB_POLLON, LAPB_COMMAND);
179         }
180
181         lapb_start_t1timer(lapb);
182         lapb_stop_t2timer(lapb);
183 }
184
185 void lapb_enquiry_response(struct lapb_cb *lapb)
186 {
187 #if LAPB_DEBUG > 1
188         printk(KERN_DEBUG "lapb: (%p) S%d TX RR(1) R%d\n",
189                lapb->dev, lapb->state, lapb->vr);
190 #endif
191
192         lapb_send_control(lapb, LAPB_RR, LAPB_POLLON, LAPB_RESPONSE);
193
194         lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
195 }
196
197 void lapb_timeout_response(struct lapb_cb *lapb)
198 {
199 #if LAPB_DEBUG > 1
200         printk(KERN_DEBUG "lapb: (%p) S%d TX RR(0) R%d\n",
201                lapb->dev, lapb->state, lapb->vr);
202 #endif
203         lapb_send_control(lapb, LAPB_RR, LAPB_POLLOFF, LAPB_RESPONSE);
204
205         lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
206 }
207
208 void lapb_check_iframes_acked(struct lapb_cb *lapb, unsigned short nr)
209 {
210         if (lapb->vs == nr) {
211                 lapb_frames_acked(lapb, nr);
212                 lapb_stop_t1timer(lapb);
213                 lapb->n2count = 0;
214         } else if (lapb->va != nr) {
215                 lapb_frames_acked(lapb, nr);
216                 lapb_start_t1timer(lapb);
217         }
218 }
219
220 void lapb_check_need_response(struct lapb_cb *lapb, int type, int pf)
221 {
222         if (type == LAPB_COMMAND && pf)
223                 lapb_enquiry_response(lapb);
224 }