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1da177e4 LT |
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 | */ | |
9 | #include <linux/errno.h> | |
10 | #include <linux/types.h> | |
11 | #include <linux/socket.h> | |
12 | #include <linux/in.h> | |
13 | #include <linux/kernel.h> | |
14 | #include <linux/sched.h> | |
15 | #include <linux/timer.h> | |
16 | #include <linux/string.h> | |
17 | #include <linux/sockios.h> | |
18 | #include <linux/net.h> | |
19 | #include <net/ax25.h> | |
20 | #include <linux/inet.h> | |
21 | #include <linux/netdevice.h> | |
22 | #include <linux/skbuff.h> | |
23 | #include <net/sock.h> | |
24 | #include <net/tcp.h> | |
25 | #include <asm/uaccess.h> | |
26 | #include <asm/system.h> | |
27 | #include <linux/fcntl.h> | |
28 | #include <linux/mm.h> | |
29 | #include <linux/interrupt.h> | |
30 | #include <net/netrom.h> | |
31 | ||
32 | /* | |
33 | * This routine purges all of the queues of frames. | |
34 | */ | |
35 | void nr_clear_queues(struct sock *sk) | |
36 | { | |
37 | struct nr_sock *nr = nr_sk(sk); | |
38 | ||
39 | skb_queue_purge(&sk->sk_write_queue); | |
40 | skb_queue_purge(&nr->ack_queue); | |
41 | skb_queue_purge(&nr->reseq_queue); | |
42 | skb_queue_purge(&nr->frag_queue); | |
43 | } | |
44 | ||
45 | /* | |
46 | * This routine purges the input queue of those frames that have been | |
47 | * acknowledged. This replaces the boxes labelled "V(a) <- N(r)" on the | |
48 | * SDL diagram. | |
49 | */ | |
50 | void nr_frames_acked(struct sock *sk, unsigned short nr) | |
51 | { | |
52 | struct nr_sock *nrom = nr_sk(sk); | |
53 | struct sk_buff *skb; | |
54 | ||
55 | /* | |
56 | * Remove all the ack-ed frames from the ack queue. | |
57 | */ | |
58 | if (nrom->va != nr) { | |
59 | while (skb_peek(&nrom->ack_queue) != NULL && nrom->va != nr) { | |
60 | skb = skb_dequeue(&nrom->ack_queue); | |
61 | kfree_skb(skb); | |
62 | nrom->va = (nrom->va + 1) % NR_MODULUS; | |
63 | } | |
64 | } | |
65 | } | |
66 | ||
67 | /* | |
68 | * Requeue all the un-ack-ed frames on the output queue to be picked | |
69 | * up by nr_kick called from the timer. This arrangement handles the | |
70 | * possibility of an empty output queue. | |
71 | */ | |
72 | void nr_requeue_frames(struct sock *sk) | |
73 | { | |
74 | struct sk_buff *skb, *skb_prev = NULL; | |
75 | ||
76 | while ((skb = skb_dequeue(&nr_sk(sk)->ack_queue)) != NULL) { | |
77 | if (skb_prev == NULL) | |
78 | skb_queue_head(&sk->sk_write_queue, skb); | |
79 | else | |
8728b834 | 80 | skb_append(skb_prev, skb, &sk->sk_write_queue); |
1da177e4 LT |
81 | skb_prev = skb; |
82 | } | |
83 | } | |
84 | ||
85 | /* | |
86 | * Validate that the value of nr is between va and vs. Return true or | |
87 | * false for testing. | |
88 | */ | |
89 | int nr_validate_nr(struct sock *sk, unsigned short nr) | |
90 | { | |
91 | struct nr_sock *nrom = nr_sk(sk); | |
92 | unsigned short vc = nrom->va; | |
93 | ||
94 | while (vc != nrom->vs) { | |
95 | if (nr == vc) return 1; | |
96 | vc = (vc + 1) % NR_MODULUS; | |
97 | } | |
98 | ||
99 | return nr == nrom->vs; | |
100 | } | |
101 | ||
102 | /* | |
103 | * Check that ns is within the receive window. | |
104 | */ | |
105 | int nr_in_rx_window(struct sock *sk, unsigned short ns) | |
106 | { | |
107 | struct nr_sock *nr = nr_sk(sk); | |
108 | unsigned short vc = nr->vr; | |
109 | unsigned short vt = (nr->vl + nr->window) % NR_MODULUS; | |
110 | ||
111 | while (vc != vt) { | |
112 | if (ns == vc) return 1; | |
113 | vc = (vc + 1) % NR_MODULUS; | |
114 | } | |
115 | ||
116 | return 0; | |
117 | } | |
118 | ||
119 | /* | |
120 | * This routine is called when the HDLC layer internally generates a | |
121 | * control frame. | |
122 | */ | |
123 | void nr_write_internal(struct sock *sk, int frametype) | |
124 | { | |
125 | struct nr_sock *nr = nr_sk(sk); | |
126 | struct sk_buff *skb; | |
127 | unsigned char *dptr; | |
128 | int len, timeout; | |
129 | ||
130 | len = NR_NETWORK_LEN + NR_TRANSPORT_LEN; | |
131 | ||
132 | switch (frametype & 0x0F) { | |
133 | case NR_CONNREQ: | |
134 | len += 17; | |
135 | break; | |
136 | case NR_CONNACK: | |
137 | len += (nr->bpqext) ? 2 : 1; | |
138 | break; | |
139 | case NR_DISCREQ: | |
140 | case NR_DISCACK: | |
141 | case NR_INFOACK: | |
142 | break; | |
143 | default: | |
144 | printk(KERN_ERR "NET/ROM: nr_write_internal - invalid frame type %d\n", frametype); | |
145 | return; | |
146 | } | |
147 | ||
148 | if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL) | |
149 | return; | |
150 | ||
151 | /* | |
152 | * Space for AX.25 and NET/ROM network header | |
153 | */ | |
154 | skb_reserve(skb, NR_NETWORK_LEN); | |
155 | ||
156 | dptr = skb_put(skb, skb_tailroom(skb)); | |
157 | ||
158 | switch (frametype & 0x0F) { | |
159 | case NR_CONNREQ: | |
160 | timeout = nr->t1 / HZ; | |
161 | *dptr++ = nr->my_index; | |
162 | *dptr++ = nr->my_id; | |
163 | *dptr++ = 0; | |
164 | *dptr++ = 0; | |
165 | *dptr++ = frametype; | |
166 | *dptr++ = nr->window; | |
167 | memcpy(dptr, &nr->user_addr, AX25_ADDR_LEN); | |
168 | dptr[6] &= ~AX25_CBIT; | |
169 | dptr[6] &= ~AX25_EBIT; | |
170 | dptr[6] |= AX25_SSSID_SPARE; | |
171 | dptr += AX25_ADDR_LEN; | |
172 | memcpy(dptr, &nr->source_addr, AX25_ADDR_LEN); | |
173 | dptr[6] &= ~AX25_CBIT; | |
174 | dptr[6] &= ~AX25_EBIT; | |
175 | dptr[6] |= AX25_SSSID_SPARE; | |
176 | dptr += AX25_ADDR_LEN; | |
177 | *dptr++ = timeout % 256; | |
178 | *dptr++ = timeout / 256; | |
179 | break; | |
180 | ||
181 | case NR_CONNACK: | |
182 | *dptr++ = nr->your_index; | |
183 | *dptr++ = nr->your_id; | |
184 | *dptr++ = nr->my_index; | |
185 | *dptr++ = nr->my_id; | |
186 | *dptr++ = frametype; | |
187 | *dptr++ = nr->window; | |
188 | if (nr->bpqext) *dptr++ = sysctl_netrom_network_ttl_initialiser; | |
189 | break; | |
190 | ||
191 | case NR_DISCREQ: | |
192 | case NR_DISCACK: | |
193 | *dptr++ = nr->your_index; | |
194 | *dptr++ = nr->your_id; | |
195 | *dptr++ = 0; | |
196 | *dptr++ = 0; | |
197 | *dptr++ = frametype; | |
198 | break; | |
199 | ||
200 | case NR_INFOACK: | |
201 | *dptr++ = nr->your_index; | |
202 | *dptr++ = nr->your_id; | |
203 | *dptr++ = 0; | |
204 | *dptr++ = nr->vr; | |
205 | *dptr++ = frametype; | |
206 | break; | |
207 | } | |
208 | ||
209 | nr_transmit_buffer(sk, skb); | |
210 | } | |
211 | ||
212 | /* | |
213 | * This routine is called when a Connect Acknowledge with the Choke Flag | |
214 | * set is needed to refuse a connection. | |
215 | */ | |
216 | void nr_transmit_refusal(struct sk_buff *skb, int mine) | |
217 | { | |
218 | struct sk_buff *skbn; | |
219 | unsigned char *dptr; | |
220 | int len; | |
221 | ||
222 | len = NR_NETWORK_LEN + NR_TRANSPORT_LEN + 1; | |
223 | ||
224 | if ((skbn = alloc_skb(len, GFP_ATOMIC)) == NULL) | |
225 | return; | |
226 | ||
227 | skb_reserve(skbn, 0); | |
228 | ||
229 | dptr = skb_put(skbn, NR_NETWORK_LEN + NR_TRANSPORT_LEN); | |
230 | ||
231 | memcpy(dptr, skb->data + 7, AX25_ADDR_LEN); | |
232 | dptr[6] &= ~AX25_CBIT; | |
233 | dptr[6] &= ~AX25_EBIT; | |
234 | dptr[6] |= AX25_SSSID_SPARE; | |
235 | dptr += AX25_ADDR_LEN; | |
236 | ||
237 | memcpy(dptr, skb->data + 0, AX25_ADDR_LEN); | |
238 | dptr[6] &= ~AX25_CBIT; | |
239 | dptr[6] |= AX25_EBIT; | |
240 | dptr[6] |= AX25_SSSID_SPARE; | |
241 | dptr += AX25_ADDR_LEN; | |
242 | ||
243 | *dptr++ = sysctl_netrom_network_ttl_initialiser; | |
244 | ||
245 | if (mine) { | |
246 | *dptr++ = 0; | |
247 | *dptr++ = 0; | |
248 | *dptr++ = skb->data[15]; | |
249 | *dptr++ = skb->data[16]; | |
250 | } else { | |
251 | *dptr++ = skb->data[15]; | |
252 | *dptr++ = skb->data[16]; | |
253 | *dptr++ = 0; | |
254 | *dptr++ = 0; | |
255 | } | |
256 | ||
257 | *dptr++ = NR_CONNACK | NR_CHOKE_FLAG; | |
258 | *dptr++ = 0; | |
259 | ||
260 | if (!nr_route_frame(skbn, NULL)) | |
261 | kfree_skb(skbn); | |
262 | } | |
263 | ||
264 | void nr_disconnect(struct sock *sk, int reason) | |
265 | { | |
266 | nr_stop_t1timer(sk); | |
267 | nr_stop_t2timer(sk); | |
268 | nr_stop_t4timer(sk); | |
269 | nr_stop_idletimer(sk); | |
270 | ||
271 | nr_clear_queues(sk); | |
272 | ||
273 | nr_sk(sk)->state = NR_STATE_0; | |
274 | ||
275 | sk->sk_state = TCP_CLOSE; | |
276 | sk->sk_err = reason; | |
277 | sk->sk_shutdown |= SEND_SHUTDOWN; | |
278 | ||
279 | if (!sock_flag(sk, SOCK_DEAD)) { | |
280 | sk->sk_state_change(sk); | |
281 | sock_set_flag(sk, SOCK_DEAD); | |
282 | } | |
283 | } |