diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /net/netrom/nr_out.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'net/netrom/nr_out.c')
-rw-r--r-- | net/netrom/nr_out.c | 274 |
1 files changed, 274 insertions, 0 deletions
diff --git a/net/netrom/nr_out.c b/net/netrom/nr_out.c new file mode 100644 index 000000000000..7939ded9c98c --- /dev/null +++ b/net/netrom/nr_out.c | |||
@@ -0,0 +1,274 @@ | |||
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/sched.h> | ||
16 | #include <linux/timer.h> | ||
17 | #include <linux/string.h> | ||
18 | #include <linux/sockios.h> | ||
19 | #include <linux/net.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 <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 is where all NET/ROM frames pass, except for IP-over-NET/ROM which | ||
34 | * cannot be fragmented in this manner. | ||
35 | */ | ||
36 | void nr_output(struct sock *sk, struct sk_buff *skb) | ||
37 | { | ||
38 | struct sk_buff *skbn; | ||
39 | unsigned char transport[NR_TRANSPORT_LEN]; | ||
40 | int err, frontlen, len; | ||
41 | |||
42 | if (skb->len - NR_TRANSPORT_LEN > NR_MAX_PACKET_SIZE) { | ||
43 | /* Save a copy of the Transport Header */ | ||
44 | memcpy(transport, skb->data, NR_TRANSPORT_LEN); | ||
45 | skb_pull(skb, NR_TRANSPORT_LEN); | ||
46 | |||
47 | frontlen = skb_headroom(skb); | ||
48 | |||
49 | while (skb->len > 0) { | ||
50 | if ((skbn = sock_alloc_send_skb(sk, frontlen + NR_MAX_PACKET_SIZE, 0, &err)) == NULL) | ||
51 | return; | ||
52 | |||
53 | skb_reserve(skbn, frontlen); | ||
54 | |||
55 | len = (NR_MAX_PACKET_SIZE > skb->len) ? skb->len : NR_MAX_PACKET_SIZE; | ||
56 | |||
57 | /* Copy the user data */ | ||
58 | memcpy(skb_put(skbn, len), skb->data, len); | ||
59 | skb_pull(skb, len); | ||
60 | |||
61 | /* Duplicate the Transport Header */ | ||
62 | skb_push(skbn, NR_TRANSPORT_LEN); | ||
63 | memcpy(skbn->data, transport, NR_TRANSPORT_LEN); | ||
64 | |||
65 | if (skb->len > 0) | ||
66 | skbn->data[4] |= NR_MORE_FLAG; | ||
67 | |||
68 | skb_queue_tail(&sk->sk_write_queue, skbn); /* Throw it on the queue */ | ||
69 | } | ||
70 | |||
71 | kfree_skb(skb); | ||
72 | } else { | ||
73 | skb_queue_tail(&sk->sk_write_queue, skb); /* Throw it on the queue */ | ||
74 | } | ||
75 | |||
76 | nr_kick(sk); | ||
77 | } | ||
78 | |||
79 | /* | ||
80 | * This procedure is passed a buffer descriptor for an iframe. It builds | ||
81 | * the rest of the control part of the frame and then writes it out. | ||
82 | */ | ||
83 | static void nr_send_iframe(struct sock *sk, struct sk_buff *skb) | ||
84 | { | ||
85 | struct nr_sock *nr = nr_sk(sk); | ||
86 | |||
87 | if (skb == NULL) | ||
88 | return; | ||
89 | |||
90 | skb->data[2] = nr->vs; | ||
91 | skb->data[3] = nr->vr; | ||
92 | |||
93 | if (nr->condition & NR_COND_OWN_RX_BUSY) | ||
94 | skb->data[4] |= NR_CHOKE_FLAG; | ||
95 | |||
96 | nr_start_idletimer(sk); | ||
97 | |||
98 | nr_transmit_buffer(sk, skb); | ||
99 | } | ||
100 | |||
101 | void nr_send_nak_frame(struct sock *sk) | ||
102 | { | ||
103 | struct sk_buff *skb, *skbn; | ||
104 | struct nr_sock *nr = nr_sk(sk); | ||
105 | |||
106 | if ((skb = skb_peek(&nr->ack_queue)) == NULL) | ||
107 | return; | ||
108 | |||
109 | if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) | ||
110 | return; | ||
111 | |||
112 | skbn->data[2] = nr->va; | ||
113 | skbn->data[3] = nr->vr; | ||
114 | |||
115 | if (nr->condition & NR_COND_OWN_RX_BUSY) | ||
116 | skbn->data[4] |= NR_CHOKE_FLAG; | ||
117 | |||
118 | nr_transmit_buffer(sk, skbn); | ||
119 | |||
120 | nr->condition &= ~NR_COND_ACK_PENDING; | ||
121 | nr->vl = nr->vr; | ||
122 | |||
123 | nr_stop_t1timer(sk); | ||
124 | } | ||
125 | |||
126 | void nr_kick(struct sock *sk) | ||
127 | { | ||
128 | struct nr_sock *nr = nr_sk(sk); | ||
129 | struct sk_buff *skb, *skbn; | ||
130 | unsigned short start, end; | ||
131 | |||
132 | if (nr->state != NR_STATE_3) | ||
133 | return; | ||
134 | |||
135 | if (nr->condition & NR_COND_PEER_RX_BUSY) | ||
136 | return; | ||
137 | |||
138 | if (!skb_peek(&sk->sk_write_queue)) | ||
139 | return; | ||
140 | |||
141 | start = (skb_peek(&nr->ack_queue) == NULL) ? nr->va : nr->vs; | ||
142 | end = (nr->va + nr->window) % NR_MODULUS; | ||
143 | |||
144 | if (start == end) | ||
145 | return; | ||
146 | |||
147 | nr->vs = start; | ||
148 | |||
149 | /* | ||
150 | * Transmit data until either we're out of data to send or | ||
151 | * the window is full. | ||
152 | */ | ||
153 | |||
154 | /* | ||
155 | * Dequeue the frame and copy it. | ||
156 | */ | ||
157 | skb = skb_dequeue(&sk->sk_write_queue); | ||
158 | |||
159 | do { | ||
160 | if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) { | ||
161 | skb_queue_head(&sk->sk_write_queue, skb); | ||
162 | break; | ||
163 | } | ||
164 | |||
165 | skb_set_owner_w(skbn, sk); | ||
166 | |||
167 | /* | ||
168 | * Transmit the frame copy. | ||
169 | */ | ||
170 | nr_send_iframe(sk, skbn); | ||
171 | |||
172 | nr->vs = (nr->vs + 1) % NR_MODULUS; | ||
173 | |||
174 | /* | ||
175 | * Requeue the original data frame. | ||
176 | */ | ||
177 | skb_queue_tail(&nr->ack_queue, skb); | ||
178 | |||
179 | } while (nr->vs != end && | ||
180 | (skb = skb_dequeue(&sk->sk_write_queue)) != NULL); | ||
181 | |||
182 | nr->vl = nr->vr; | ||
183 | nr->condition &= ~NR_COND_ACK_PENDING; | ||
184 | |||
185 | if (!nr_t1timer_running(sk)) | ||
186 | nr_start_t1timer(sk); | ||
187 | } | ||
188 | |||
189 | void nr_transmit_buffer(struct sock *sk, struct sk_buff *skb) | ||
190 | { | ||
191 | struct nr_sock *nr = nr_sk(sk); | ||
192 | unsigned char *dptr; | ||
193 | |||
194 | /* | ||
195 | * Add the protocol byte and network header. | ||
196 | */ | ||
197 | dptr = skb_push(skb, NR_NETWORK_LEN); | ||
198 | |||
199 | memcpy(dptr, &nr->source_addr, AX25_ADDR_LEN); | ||
200 | dptr[6] &= ~AX25_CBIT; | ||
201 | dptr[6] &= ~AX25_EBIT; | ||
202 | dptr[6] |= AX25_SSSID_SPARE; | ||
203 | dptr += AX25_ADDR_LEN; | ||
204 | |||
205 | memcpy(dptr, &nr->dest_addr, AX25_ADDR_LEN); | ||
206 | dptr[6] &= ~AX25_CBIT; | ||
207 | dptr[6] |= AX25_EBIT; | ||
208 | dptr[6] |= AX25_SSSID_SPARE; | ||
209 | dptr += AX25_ADDR_LEN; | ||
210 | |||
211 | *dptr++ = sysctl_netrom_network_ttl_initialiser; | ||
212 | |||
213 | if (!nr_route_frame(skb, NULL)) { | ||
214 | kfree_skb(skb); | ||
215 | nr_disconnect(sk, ENETUNREACH); | ||
216 | } | ||
217 | } | ||
218 | |||
219 | /* | ||
220 | * The following routines are taken from page 170 of the 7th ARRL Computer | ||
221 | * Networking Conference paper, as is the whole state machine. | ||
222 | */ | ||
223 | |||
224 | void nr_establish_data_link(struct sock *sk) | ||
225 | { | ||
226 | struct nr_sock *nr = nr_sk(sk); | ||
227 | |||
228 | nr->condition = 0x00; | ||
229 | nr->n2count = 0; | ||
230 | |||
231 | nr_write_internal(sk, NR_CONNREQ); | ||
232 | |||
233 | nr_stop_t2timer(sk); | ||
234 | nr_stop_t4timer(sk); | ||
235 | nr_stop_idletimer(sk); | ||
236 | nr_start_t1timer(sk); | ||
237 | } | ||
238 | |||
239 | /* | ||
240 | * Never send a NAK when we are CHOKEd. | ||
241 | */ | ||
242 | void nr_enquiry_response(struct sock *sk) | ||
243 | { | ||
244 | struct nr_sock *nr = nr_sk(sk); | ||
245 | int frametype = NR_INFOACK; | ||
246 | |||
247 | if (nr->condition & NR_COND_OWN_RX_BUSY) { | ||
248 | frametype |= NR_CHOKE_FLAG; | ||
249 | } else { | ||
250 | if (skb_peek(&nr->reseq_queue) != NULL) | ||
251 | frametype |= NR_NAK_FLAG; | ||
252 | } | ||
253 | |||
254 | nr_write_internal(sk, frametype); | ||
255 | |||
256 | nr->vl = nr->vr; | ||
257 | nr->condition &= ~NR_COND_ACK_PENDING; | ||
258 | } | ||
259 | |||
260 | void nr_check_iframes_acked(struct sock *sk, unsigned short nr) | ||
261 | { | ||
262 | struct nr_sock *nrom = nr_sk(sk); | ||
263 | |||
264 | if (nrom->vs == nr) { | ||
265 | nr_frames_acked(sk, nr); | ||
266 | nr_stop_t1timer(sk); | ||
267 | nrom->n2count = 0; | ||
268 | } else { | ||
269 | if (nrom->va != nr) { | ||
270 | nr_frames_acked(sk, nr); | ||
271 | nr_start_t1timer(sk); | ||
272 | } | ||
273 | } | ||
274 | } | ||