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1/*
2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License as published by
4 * the Free Software Foundation; either version 2 of the License, or
5 * (at your option) any later version.
6 *
7 * Copyright Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
8 * Copyright Darryl Miles G7LED (dlm@g7led.demon.co.uk)
9 */
10#include <linux/errno.h>
11#include <linux/types.h>
12#include <linux/socket.h>
13#include <linux/in.h>
14#include <linux/kernel.h>
15#include <linux/timer.h>
16#include <linux/string.h>
17#include <linux/sockios.h>
18#include <linux/net.h>
19#include <linux/slab.h>
20#include <net/ax25.h>
21#include <linux/inet.h>
22#include <linux/netdevice.h>
23#include <linux/skbuff.h>
24#include <net/sock.h>
25#include <net/tcp_states.h>
26#include <linux/uaccess.h>
27#include <linux/fcntl.h>
28#include <linux/mm.h>
29#include <linux/interrupt.h>
30#include <net/netrom.h>
31
32static int nr_queue_rx_frame(struct sock *sk, struct sk_buff *skb, int more)
33{
34 struct sk_buff *skbo, *skbn = skb;
35 struct nr_sock *nr = nr_sk(sk);
36
37 skb_pull(skb, NR_NETWORK_LEN + NR_TRANSPORT_LEN);
38
39 nr_start_idletimer(sk);
40
41 if (more) {
42 nr->fraglen += skb->len;
43 skb_queue_tail(&nr->frag_queue, skb);
44 return 0;
45 }
46
47 if (!more && nr->fraglen > 0) { /* End of fragment */
48 nr->fraglen += skb->len;
49 skb_queue_tail(&nr->frag_queue, skb);
50
51 if ((skbn = alloc_skb(nr->fraglen, GFP_ATOMIC)) == NULL)
52 return 1;
53
54 skb_reset_transport_header(skbn);
55
56 while ((skbo = skb_dequeue(&nr->frag_queue)) != NULL) {
57 skb_copy_from_linear_data(skbo,
58 skb_put(skbn, skbo->len),
59 skbo->len);
60 kfree_skb(skbo);
61 }
62
63 nr->fraglen = 0;
64 }
65
66 return sock_queue_rcv_skb(sk, skbn);
67}
68
69/*
70 * State machine for state 1, Awaiting Connection State.
71 * The handling of the timer(s) is in file nr_timer.c.
72 * Handling of state 0 and connection release is in netrom.c.
73 */
74static int nr_state1_machine(struct sock *sk, struct sk_buff *skb,
75 int frametype)
76{
77 switch (frametype) {
78 case NR_CONNACK: {
79 struct nr_sock *nr = nr_sk(sk);
80
81 nr_stop_t1timer(sk);
82 nr_start_idletimer(sk);
83 nr->your_index = skb->data[17];
84 nr->your_id = skb->data[18];
85 nr->vs = 0;
86 nr->va = 0;
87 nr->vr = 0;
88 nr->vl = 0;
89 nr->state = NR_STATE_3;
90 nr->n2count = 0;
91 nr->window = skb->data[20];
92 sk->sk_state = TCP_ESTABLISHED;
93 if (!sock_flag(sk, SOCK_DEAD))
94 sk->sk_state_change(sk);
95 break;
96 }
97
98 case NR_CONNACK | NR_CHOKE_FLAG:
99 nr_disconnect(sk, ECONNREFUSED);
100 break;
101
102 case NR_RESET:
103 if (sysctl_netrom_reset_circuit)
104 nr_disconnect(sk, ECONNRESET);
105 break;
106
107 default:
108 break;
109 }
110 return 0;
111}
112
113/*
114 * State machine for state 2, Awaiting Release State.
115 * The handling of the timer(s) is in file nr_timer.c
116 * Handling of state 0 and connection release is in netrom.c.
117 */
118static int nr_state2_machine(struct sock *sk, struct sk_buff *skb,
119 int frametype)
120{
121 switch (frametype) {
122 case NR_CONNACK | NR_CHOKE_FLAG:
123 nr_disconnect(sk, ECONNRESET);
124 break;
125
126 case NR_DISCREQ:
127 nr_write_internal(sk, NR_DISCACK);
128
129 case NR_DISCACK:
130 nr_disconnect(sk, 0);
131 break;
132
133 case NR_RESET:
134 if (sysctl_netrom_reset_circuit)
135 nr_disconnect(sk, ECONNRESET);
136 break;
137
138 default:
139 break;
140 }
141 return 0;
142}
143
144/*
145 * State machine for state 3, Connected State.
146 * The handling of the timer(s) is in file nr_timer.c
147 * Handling of state 0 and connection release is in netrom.c.
148 */
149static int nr_state3_machine(struct sock *sk, struct sk_buff *skb, int frametype)
150{
151 struct nr_sock *nrom = nr_sk(sk);
152 struct sk_buff_head temp_queue;
153 struct sk_buff *skbn;
154 unsigned short save_vr;
155 unsigned short nr, ns;
156 int queued = 0;
157
158 nr = skb->data[18];
159 ns = skb->data[17];
160
161 switch (frametype) {
162 case NR_CONNREQ:
163 nr_write_internal(sk, NR_CONNACK);
164 break;
165
166 case NR_DISCREQ:
167 nr_write_internal(sk, NR_DISCACK);
168 nr_disconnect(sk, 0);
169 break;
170
171 case NR_CONNACK | NR_CHOKE_FLAG:
172 case NR_DISCACK:
173 nr_disconnect(sk, ECONNRESET);
174 break;
175
176 case NR_INFOACK:
177 case NR_INFOACK | NR_CHOKE_FLAG:
178 case NR_INFOACK | NR_NAK_FLAG:
179 case NR_INFOACK | NR_NAK_FLAG | NR_CHOKE_FLAG:
180 if (frametype & NR_CHOKE_FLAG) {
181 nrom->condition |= NR_COND_PEER_RX_BUSY;
182 nr_start_t4timer(sk);
183 } else {
184 nrom->condition &= ~NR_COND_PEER_RX_BUSY;
185 nr_stop_t4timer(sk);
186 }
187 if (!nr_validate_nr(sk, nr)) {
188 break;
189 }
190 if (frametype & NR_NAK_FLAG) {
191 nr_frames_acked(sk, nr);
192 nr_send_nak_frame(sk);
193 } else {
194 if (nrom->condition & NR_COND_PEER_RX_BUSY) {
195 nr_frames_acked(sk, nr);
196 } else {
197 nr_check_iframes_acked(sk, nr);
198 }
199 }
200 break;
201
202 case NR_INFO:
203 case NR_INFO | NR_NAK_FLAG:
204 case NR_INFO | NR_CHOKE_FLAG:
205 case NR_INFO | NR_MORE_FLAG:
206 case NR_INFO | NR_NAK_FLAG | NR_CHOKE_FLAG:
207 case NR_INFO | NR_CHOKE_FLAG | NR_MORE_FLAG:
208 case NR_INFO | NR_NAK_FLAG | NR_MORE_FLAG:
209 case NR_INFO | NR_NAK_FLAG | NR_CHOKE_FLAG | NR_MORE_FLAG:
210 if (frametype & NR_CHOKE_FLAG) {
211 nrom->condition |= NR_COND_PEER_RX_BUSY;
212 nr_start_t4timer(sk);
213 } else {
214 nrom->condition &= ~NR_COND_PEER_RX_BUSY;
215 nr_stop_t4timer(sk);
216 }
217 if (nr_validate_nr(sk, nr)) {
218 if (frametype & NR_NAK_FLAG) {
219 nr_frames_acked(sk, nr);
220 nr_send_nak_frame(sk);
221 } else {
222 if (nrom->condition & NR_COND_PEER_RX_BUSY) {
223 nr_frames_acked(sk, nr);
224 } else {
225 nr_check_iframes_acked(sk, nr);
226 }
227 }
228 }
229 queued = 1;
230 skb_queue_head(&nrom->reseq_queue, skb);
231 if (nrom->condition & NR_COND_OWN_RX_BUSY)
232 break;
233 skb_queue_head_init(&temp_queue);
234 do {
235 save_vr = nrom->vr;
236 while ((skbn = skb_dequeue(&nrom->reseq_queue)) != NULL) {
237 ns = skbn->data[17];
238 if (ns == nrom->vr) {
239 if (nr_queue_rx_frame(sk, skbn, frametype & NR_MORE_FLAG) == 0) {
240 nrom->vr = (nrom->vr + 1) % NR_MODULUS;
241 } else {
242 nrom->condition |= NR_COND_OWN_RX_BUSY;
243 skb_queue_tail(&temp_queue, skbn);
244 }
245 } else if (nr_in_rx_window(sk, ns)) {
246 skb_queue_tail(&temp_queue, skbn);
247 } else {
248 kfree_skb(skbn);
249 }
250 }
251 while ((skbn = skb_dequeue(&temp_queue)) != NULL) {
252 skb_queue_tail(&nrom->reseq_queue, skbn);
253 }
254 } while (save_vr != nrom->vr);
255 /*
256 * Window is full, ack it immediately.
257 */
258 if (((nrom->vl + nrom->window) % NR_MODULUS) == nrom->vr) {
259 nr_enquiry_response(sk);
260 } else {
261 if (!(nrom->condition & NR_COND_ACK_PENDING)) {
262 nrom->condition |= NR_COND_ACK_PENDING;
263 nr_start_t2timer(sk);
264 }
265 }
266 break;
267
268 case NR_RESET:
269 if (sysctl_netrom_reset_circuit)
270 nr_disconnect(sk, ECONNRESET);
271 break;
272
273 default:
274 break;
275 }
276 return queued;
277}
278
279/* Higher level upcall for a LAPB frame - called with sk locked */
280int nr_process_rx_frame(struct sock *sk, struct sk_buff *skb)
281{
282 struct nr_sock *nr = nr_sk(sk);
283 int queued = 0, frametype;
284
285 if (nr->state == NR_STATE_0)
286 return 0;
287
288 frametype = skb->data[19];
289
290 switch (nr->state) {
291 case NR_STATE_1:
292 queued = nr_state1_machine(sk, skb, frametype);
293 break;
294 case NR_STATE_2:
295 queued = nr_state2_machine(sk, skb, frametype);
296 break;
297 case NR_STATE_3:
298 queued = nr_state3_machine(sk, skb, frametype);
299 break;
300 }
301
302 nr_kick(sk);
303
304 return queued;
305}
1/*
2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License as published by
4 * the Free Software Foundation; either version 2 of the License, or
5 * (at your option) any later version.
6 *
7 * Copyright Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
8 * Copyright Darryl Miles G7LED (dlm@g7led.demon.co.uk)
9 */
10#include <linux/errno.h>
11#include <linux/types.h>
12#include <linux/socket.h>
13#include <linux/in.h>
14#include <linux/kernel.h>
15#include <linux/timer.h>
16#include <linux/string.h>
17#include <linux/sockios.h>
18#include <linux/net.h>
19#include <linux/slab.h>
20#include <net/ax25.h>
21#include <linux/inet.h>
22#include <linux/netdevice.h>
23#include <linux/skbuff.h>
24#include <net/sock.h>
25#include <net/tcp_states.h>
26#include <asm/uaccess.h>
27#include <asm/system.h>
28#include <linux/fcntl.h>
29#include <linux/mm.h>
30#include <linux/interrupt.h>
31#include <net/netrom.h>
32
33static int nr_queue_rx_frame(struct sock *sk, struct sk_buff *skb, int more)
34{
35 struct sk_buff *skbo, *skbn = skb;
36 struct nr_sock *nr = nr_sk(sk);
37
38 skb_pull(skb, NR_NETWORK_LEN + NR_TRANSPORT_LEN);
39
40 nr_start_idletimer(sk);
41
42 if (more) {
43 nr->fraglen += skb->len;
44 skb_queue_tail(&nr->frag_queue, skb);
45 return 0;
46 }
47
48 if (!more && nr->fraglen > 0) { /* End of fragment */
49 nr->fraglen += skb->len;
50 skb_queue_tail(&nr->frag_queue, skb);
51
52 if ((skbn = alloc_skb(nr->fraglen, GFP_ATOMIC)) == NULL)
53 return 1;
54
55 skb_reset_transport_header(skbn);
56
57 while ((skbo = skb_dequeue(&nr->frag_queue)) != NULL) {
58 skb_copy_from_linear_data(skbo,
59 skb_put(skbn, skbo->len),
60 skbo->len);
61 kfree_skb(skbo);
62 }
63
64 nr->fraglen = 0;
65 }
66
67 return sock_queue_rcv_skb(sk, skbn);
68}
69
70/*
71 * State machine for state 1, Awaiting Connection State.
72 * The handling of the timer(s) is in file nr_timer.c.
73 * Handling of state 0 and connection release is in netrom.c.
74 */
75static int nr_state1_machine(struct sock *sk, struct sk_buff *skb,
76 int frametype)
77{
78 switch (frametype) {
79 case NR_CONNACK: {
80 struct nr_sock *nr = nr_sk(sk);
81
82 nr_stop_t1timer(sk);
83 nr_start_idletimer(sk);
84 nr->your_index = skb->data[17];
85 nr->your_id = skb->data[18];
86 nr->vs = 0;
87 nr->va = 0;
88 nr->vr = 0;
89 nr->vl = 0;
90 nr->state = NR_STATE_3;
91 nr->n2count = 0;
92 nr->window = skb->data[20];
93 sk->sk_state = TCP_ESTABLISHED;
94 if (!sock_flag(sk, SOCK_DEAD))
95 sk->sk_state_change(sk);
96 break;
97 }
98
99 case NR_CONNACK | NR_CHOKE_FLAG:
100 nr_disconnect(sk, ECONNREFUSED);
101 break;
102
103 case NR_RESET:
104 if (sysctl_netrom_reset_circuit)
105 nr_disconnect(sk, ECONNRESET);
106 break;
107
108 default:
109 break;
110 }
111 return 0;
112}
113
114/*
115 * State machine for state 2, Awaiting Release State.
116 * The handling of the timer(s) is in file nr_timer.c
117 * Handling of state 0 and connection release is in netrom.c.
118 */
119static int nr_state2_machine(struct sock *sk, struct sk_buff *skb,
120 int frametype)
121{
122 switch (frametype) {
123 case NR_CONNACK | NR_CHOKE_FLAG:
124 nr_disconnect(sk, ECONNRESET);
125 break;
126
127 case NR_DISCREQ:
128 nr_write_internal(sk, NR_DISCACK);
129
130 case NR_DISCACK:
131 nr_disconnect(sk, 0);
132 break;
133
134 case NR_RESET:
135 if (sysctl_netrom_reset_circuit)
136 nr_disconnect(sk, ECONNRESET);
137 break;
138
139 default:
140 break;
141 }
142 return 0;
143}
144
145/*
146 * State machine for state 3, Connected State.
147 * The handling of the timer(s) is in file nr_timer.c
148 * Handling of state 0 and connection release is in netrom.c.
149 */
150static int nr_state3_machine(struct sock *sk, struct sk_buff *skb, int frametype)
151{
152 struct nr_sock *nrom = nr_sk(sk);
153 struct sk_buff_head temp_queue;
154 struct sk_buff *skbn;
155 unsigned short save_vr;
156 unsigned short nr, ns;
157 int queued = 0;
158
159 nr = skb->data[18];
160 ns = skb->data[17];
161
162 switch (frametype) {
163 case NR_CONNREQ:
164 nr_write_internal(sk, NR_CONNACK);
165 break;
166
167 case NR_DISCREQ:
168 nr_write_internal(sk, NR_DISCACK);
169 nr_disconnect(sk, 0);
170 break;
171
172 case NR_CONNACK | NR_CHOKE_FLAG:
173 case NR_DISCACK:
174 nr_disconnect(sk, ECONNRESET);
175 break;
176
177 case NR_INFOACK:
178 case NR_INFOACK | NR_CHOKE_FLAG:
179 case NR_INFOACK | NR_NAK_FLAG:
180 case NR_INFOACK | NR_NAK_FLAG | NR_CHOKE_FLAG:
181 if (frametype & NR_CHOKE_FLAG) {
182 nrom->condition |= NR_COND_PEER_RX_BUSY;
183 nr_start_t4timer(sk);
184 } else {
185 nrom->condition &= ~NR_COND_PEER_RX_BUSY;
186 nr_stop_t4timer(sk);
187 }
188 if (!nr_validate_nr(sk, nr)) {
189 break;
190 }
191 if (frametype & NR_NAK_FLAG) {
192 nr_frames_acked(sk, nr);
193 nr_send_nak_frame(sk);
194 } else {
195 if (nrom->condition & NR_COND_PEER_RX_BUSY) {
196 nr_frames_acked(sk, nr);
197 } else {
198 nr_check_iframes_acked(sk, nr);
199 }
200 }
201 break;
202
203 case NR_INFO:
204 case NR_INFO | NR_NAK_FLAG:
205 case NR_INFO | NR_CHOKE_FLAG:
206 case NR_INFO | NR_MORE_FLAG:
207 case NR_INFO | NR_NAK_FLAG | NR_CHOKE_FLAG:
208 case NR_INFO | NR_CHOKE_FLAG | NR_MORE_FLAG:
209 case NR_INFO | NR_NAK_FLAG | NR_MORE_FLAG:
210 case NR_INFO | NR_NAK_FLAG | NR_CHOKE_FLAG | NR_MORE_FLAG:
211 if (frametype & NR_CHOKE_FLAG) {
212 nrom->condition |= NR_COND_PEER_RX_BUSY;
213 nr_start_t4timer(sk);
214 } else {
215 nrom->condition &= ~NR_COND_PEER_RX_BUSY;
216 nr_stop_t4timer(sk);
217 }
218 if (nr_validate_nr(sk, nr)) {
219 if (frametype & NR_NAK_FLAG) {
220 nr_frames_acked(sk, nr);
221 nr_send_nak_frame(sk);
222 } else {
223 if (nrom->condition & NR_COND_PEER_RX_BUSY) {
224 nr_frames_acked(sk, nr);
225 } else {
226 nr_check_iframes_acked(sk, nr);
227 }
228 }
229 }
230 queued = 1;
231 skb_queue_head(&nrom->reseq_queue, skb);
232 if (nrom->condition & NR_COND_OWN_RX_BUSY)
233 break;
234 skb_queue_head_init(&temp_queue);
235 do {
236 save_vr = nrom->vr;
237 while ((skbn = skb_dequeue(&nrom->reseq_queue)) != NULL) {
238 ns = skbn->data[17];
239 if (ns == nrom->vr) {
240 if (nr_queue_rx_frame(sk, skbn, frametype & NR_MORE_FLAG) == 0) {
241 nrom->vr = (nrom->vr + 1) % NR_MODULUS;
242 } else {
243 nrom->condition |= NR_COND_OWN_RX_BUSY;
244 skb_queue_tail(&temp_queue, skbn);
245 }
246 } else if (nr_in_rx_window(sk, ns)) {
247 skb_queue_tail(&temp_queue, skbn);
248 } else {
249 kfree_skb(skbn);
250 }
251 }
252 while ((skbn = skb_dequeue(&temp_queue)) != NULL) {
253 skb_queue_tail(&nrom->reseq_queue, skbn);
254 }
255 } while (save_vr != nrom->vr);
256 /*
257 * Window is full, ack it immediately.
258 */
259 if (((nrom->vl + nrom->window) % NR_MODULUS) == nrom->vr) {
260 nr_enquiry_response(sk);
261 } else {
262 if (!(nrom->condition & NR_COND_ACK_PENDING)) {
263 nrom->condition |= NR_COND_ACK_PENDING;
264 nr_start_t2timer(sk);
265 }
266 }
267 break;
268
269 case NR_RESET:
270 if (sysctl_netrom_reset_circuit)
271 nr_disconnect(sk, ECONNRESET);
272 break;
273
274 default:
275 break;
276 }
277 return queued;
278}
279
280/* Higher level upcall for a LAPB frame - called with sk locked */
281int nr_process_rx_frame(struct sock *sk, struct sk_buff *skb)
282{
283 struct nr_sock *nr = nr_sk(sk);
284 int queued = 0, frametype;
285
286 if (nr->state == NR_STATE_0)
287 return 0;
288
289 frametype = skb->data[19];
290
291 switch (nr->state) {
292 case NR_STATE_1:
293 queued = nr_state1_machine(sk, skb, frametype);
294 break;
295 case NR_STATE_2:
296 queued = nr_state2_machine(sk, skb, frametype);
297 break;
298 case NR_STATE_3:
299 queued = nr_state3_machine(sk, skb, frametype);
300 break;
301 }
302
303 nr_kick(sk);
304
305 return queued;
306}