Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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> |
Arnaldo Carvalho de Melo | c752f07 | 2005-08-09 20:08:28 -0700 | [diff] [blame] | 24 | #include <net/tcp_states.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | static 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 | skbn->h.raw = skbn->data; |
| 55 | |
| 56 | while ((skbo = skb_dequeue(&nr->frag_queue)) != NULL) { |
| 57 | memcpy(skb_put(skbn, skbo->len), skbo->data, skbo->len); |
| 58 | kfree_skb(skbo); |
| 59 | } |
| 60 | |
| 61 | nr->fraglen = 0; |
| 62 | } |
| 63 | |
| 64 | return sock_queue_rcv_skb(sk, skbn); |
| 65 | } |
| 66 | |
| 67 | /* |
| 68 | * State machine for state 1, Awaiting Connection State. |
| 69 | * The handling of the timer(s) is in file nr_timer.c. |
| 70 | * Handling of state 0 and connection release is in netrom.c. |
| 71 | */ |
| 72 | static int nr_state1_machine(struct sock *sk, struct sk_buff *skb, |
| 73 | int frametype) |
| 74 | { |
| 75 | switch (frametype) { |
| 76 | case NR_CONNACK: { |
| 77 | struct nr_sock *nr = nr_sk(sk); |
| 78 | |
| 79 | nr_stop_t1timer(sk); |
| 80 | nr_start_idletimer(sk); |
| 81 | nr->your_index = skb->data[17]; |
| 82 | nr->your_id = skb->data[18]; |
| 83 | nr->vs = 0; |
| 84 | nr->va = 0; |
| 85 | nr->vr = 0; |
| 86 | nr->vl = 0; |
| 87 | nr->state = NR_STATE_3; |
| 88 | nr->n2count = 0; |
| 89 | nr->window = skb->data[20]; |
| 90 | sk->sk_state = TCP_ESTABLISHED; |
| 91 | if (!sock_flag(sk, SOCK_DEAD)) |
| 92 | sk->sk_state_change(sk); |
| 93 | break; |
| 94 | } |
| 95 | |
| 96 | case NR_CONNACK | NR_CHOKE_FLAG: |
| 97 | nr_disconnect(sk, ECONNREFUSED); |
| 98 | break; |
| 99 | |
Ralf Baechle | e21ce8c | 2005-09-12 14:27:37 -0700 | [diff] [blame] | 100 | case NR_RESET: |
Mika Kukkonen | 0d77d59 | 2005-12-21 18:38:26 -0800 | [diff] [blame] | 101 | if (sysctl_netrom_reset_circuit) |
Ralf Baechle | e21ce8c | 2005-09-12 14:27:37 -0700 | [diff] [blame] | 102 | nr_disconnect(sk, ECONNRESET); |
| 103 | break; |
| 104 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 105 | default: |
| 106 | break; |
| 107 | } |
| 108 | return 0; |
| 109 | } |
| 110 | |
| 111 | /* |
| 112 | * State machine for state 2, Awaiting Release State. |
| 113 | * The handling of the timer(s) is in file nr_timer.c |
| 114 | * Handling of state 0 and connection release is in netrom.c. |
| 115 | */ |
| 116 | static int nr_state2_machine(struct sock *sk, struct sk_buff *skb, |
| 117 | int frametype) |
| 118 | { |
| 119 | switch (frametype) { |
| 120 | case NR_CONNACK | NR_CHOKE_FLAG: |
| 121 | nr_disconnect(sk, ECONNRESET); |
| 122 | break; |
| 123 | |
| 124 | case NR_DISCREQ: |
| 125 | nr_write_internal(sk, NR_DISCACK); |
| 126 | |
| 127 | case NR_DISCACK: |
| 128 | nr_disconnect(sk, 0); |
| 129 | break; |
| 130 | |
Ralf Baechle | e21ce8c | 2005-09-12 14:27:37 -0700 | [diff] [blame] | 131 | case NR_RESET: |
Mika Kukkonen | 0d77d59 | 2005-12-21 18:38:26 -0800 | [diff] [blame] | 132 | if (sysctl_netrom_reset_circuit) |
Ralf Baechle | e21ce8c | 2005-09-12 14:27:37 -0700 | [diff] [blame] | 133 | nr_disconnect(sk, ECONNRESET); |
| 134 | break; |
| 135 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 136 | default: |
| 137 | break; |
| 138 | } |
| 139 | return 0; |
| 140 | } |
| 141 | |
| 142 | /* |
| 143 | * State machine for state 3, Connected State. |
| 144 | * The handling of the timer(s) is in file nr_timer.c |
| 145 | * Handling of state 0 and connection release is in netrom.c. |
| 146 | */ |
| 147 | static int nr_state3_machine(struct sock *sk, struct sk_buff *skb, int frametype) |
| 148 | { |
| 149 | struct nr_sock *nrom = nr_sk(sk); |
| 150 | struct sk_buff_head temp_queue; |
| 151 | struct sk_buff *skbn; |
| 152 | unsigned short save_vr; |
| 153 | unsigned short nr, ns; |
| 154 | int queued = 0; |
| 155 | |
| 156 | nr = skb->data[18]; |
| 157 | ns = skb->data[17]; |
| 158 | |
| 159 | switch (frametype) { |
| 160 | case NR_CONNREQ: |
| 161 | nr_write_internal(sk, NR_CONNACK); |
| 162 | break; |
| 163 | |
| 164 | case NR_DISCREQ: |
| 165 | nr_write_internal(sk, NR_DISCACK); |
| 166 | nr_disconnect(sk, 0); |
| 167 | break; |
| 168 | |
| 169 | case NR_CONNACK | NR_CHOKE_FLAG: |
| 170 | case NR_DISCACK: |
| 171 | nr_disconnect(sk, ECONNRESET); |
| 172 | break; |
| 173 | |
| 174 | case NR_INFOACK: |
| 175 | case NR_INFOACK | NR_CHOKE_FLAG: |
| 176 | case NR_INFOACK | NR_NAK_FLAG: |
| 177 | case NR_INFOACK | NR_NAK_FLAG | NR_CHOKE_FLAG: |
| 178 | if (frametype & NR_CHOKE_FLAG) { |
| 179 | nrom->condition |= NR_COND_PEER_RX_BUSY; |
| 180 | nr_start_t4timer(sk); |
| 181 | } else { |
| 182 | nrom->condition &= ~NR_COND_PEER_RX_BUSY; |
| 183 | nr_stop_t4timer(sk); |
| 184 | } |
| 185 | if (!nr_validate_nr(sk, nr)) { |
| 186 | break; |
| 187 | } |
| 188 | if (frametype & NR_NAK_FLAG) { |
| 189 | nr_frames_acked(sk, nr); |
| 190 | nr_send_nak_frame(sk); |
| 191 | } else { |
| 192 | if (nrom->condition & NR_COND_PEER_RX_BUSY) { |
| 193 | nr_frames_acked(sk, nr); |
| 194 | } else { |
| 195 | nr_check_iframes_acked(sk, nr); |
| 196 | } |
| 197 | } |
| 198 | break; |
| 199 | |
| 200 | case NR_INFO: |
| 201 | case NR_INFO | NR_NAK_FLAG: |
| 202 | case NR_INFO | NR_CHOKE_FLAG: |
| 203 | case NR_INFO | NR_MORE_FLAG: |
| 204 | case NR_INFO | NR_NAK_FLAG | NR_CHOKE_FLAG: |
| 205 | case NR_INFO | NR_CHOKE_FLAG | NR_MORE_FLAG: |
| 206 | case NR_INFO | NR_NAK_FLAG | NR_MORE_FLAG: |
| 207 | case NR_INFO | NR_NAK_FLAG | NR_CHOKE_FLAG | NR_MORE_FLAG: |
| 208 | if (frametype & NR_CHOKE_FLAG) { |
| 209 | nrom->condition |= NR_COND_PEER_RX_BUSY; |
| 210 | nr_start_t4timer(sk); |
| 211 | } else { |
| 212 | nrom->condition &= ~NR_COND_PEER_RX_BUSY; |
| 213 | nr_stop_t4timer(sk); |
| 214 | } |
| 215 | if (nr_validate_nr(sk, nr)) { |
| 216 | if (frametype & NR_NAK_FLAG) { |
| 217 | nr_frames_acked(sk, nr); |
| 218 | nr_send_nak_frame(sk); |
| 219 | } else { |
| 220 | if (nrom->condition & NR_COND_PEER_RX_BUSY) { |
| 221 | nr_frames_acked(sk, nr); |
| 222 | } else { |
| 223 | nr_check_iframes_acked(sk, nr); |
| 224 | } |
| 225 | } |
| 226 | } |
| 227 | queued = 1; |
| 228 | skb_queue_head(&nrom->reseq_queue, skb); |
| 229 | if (nrom->condition & NR_COND_OWN_RX_BUSY) |
| 230 | break; |
| 231 | skb_queue_head_init(&temp_queue); |
| 232 | do { |
| 233 | save_vr = nrom->vr; |
| 234 | while ((skbn = skb_dequeue(&nrom->reseq_queue)) != NULL) { |
| 235 | ns = skbn->data[17]; |
| 236 | if (ns == nrom->vr) { |
| 237 | if (nr_queue_rx_frame(sk, skbn, frametype & NR_MORE_FLAG) == 0) { |
| 238 | nrom->vr = (nrom->vr + 1) % NR_MODULUS; |
| 239 | } else { |
| 240 | nrom->condition |= NR_COND_OWN_RX_BUSY; |
| 241 | skb_queue_tail(&temp_queue, skbn); |
| 242 | } |
| 243 | } else if (nr_in_rx_window(sk, ns)) { |
| 244 | skb_queue_tail(&temp_queue, skbn); |
| 245 | } else { |
| 246 | kfree_skb(skbn); |
| 247 | } |
| 248 | } |
| 249 | while ((skbn = skb_dequeue(&temp_queue)) != NULL) { |
| 250 | skb_queue_tail(&nrom->reseq_queue, skbn); |
| 251 | } |
| 252 | } while (save_vr != nrom->vr); |
| 253 | /* |
| 254 | * Window is full, ack it immediately. |
| 255 | */ |
| 256 | if (((nrom->vl + nrom->window) % NR_MODULUS) == nrom->vr) { |
| 257 | nr_enquiry_response(sk); |
| 258 | } else { |
| 259 | if (!(nrom->condition & NR_COND_ACK_PENDING)) { |
| 260 | nrom->condition |= NR_COND_ACK_PENDING; |
| 261 | nr_start_t2timer(sk); |
| 262 | } |
| 263 | } |
| 264 | break; |
| 265 | |
Ralf Baechle | e21ce8c | 2005-09-12 14:27:37 -0700 | [diff] [blame] | 266 | case NR_RESET: |
Mika Kukkonen | 0d77d59 | 2005-12-21 18:38:26 -0800 | [diff] [blame] | 267 | if (sysctl_netrom_reset_circuit) |
Ralf Baechle | e21ce8c | 2005-09-12 14:27:37 -0700 | [diff] [blame] | 268 | nr_disconnect(sk, ECONNRESET); |
| 269 | break; |
| 270 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 271 | default: |
| 272 | break; |
| 273 | } |
| 274 | return queued; |
| 275 | } |
| 276 | |
| 277 | /* Higher level upcall for a LAPB frame - called with sk locked */ |
| 278 | int nr_process_rx_frame(struct sock *sk, struct sk_buff *skb) |
| 279 | { |
| 280 | struct nr_sock *nr = nr_sk(sk); |
| 281 | int queued = 0, frametype; |
| 282 | |
| 283 | if (nr->state == NR_STATE_0) |
| 284 | return 0; |
| 285 | |
| 286 | frametype = skb->data[19]; |
| 287 | |
| 288 | switch (nr->state) { |
| 289 | case NR_STATE_1: |
| 290 | queued = nr_state1_machine(sk, skb, frametype); |
| 291 | break; |
| 292 | case NR_STATE_2: |
| 293 | queued = nr_state2_machine(sk, skb, frametype); |
| 294 | break; |
| 295 | case NR_STATE_3: |
| 296 | queued = nr_state3_machine(sk, skb, frametype); |
| 297 | break; |
| 298 | } |
| 299 | |
| 300 | nr_kick(sk); |
| 301 | |
| 302 | return queued; |
| 303 | } |