Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * X.25 Packet Layer release 002 |
| 3 | * |
| 4 | * This is ALPHA test software. This code may break your machine, |
| 5 | * randomly fail to work with new releases, misbehave and/or generally |
YOSHIFUJI Hideaki | f8e1d201 | 2007-02-09 23:25:27 +0900 | [diff] [blame] | 6 | * screw up. It might even work. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 7 | * |
| 8 | * This code REQUIRES 2.1.15 or higher |
| 9 | * |
| 10 | * This module: |
| 11 | * This module is free software; you can redistribute it and/or |
| 12 | * modify it under the terms of the GNU General Public License |
| 13 | * as published by the Free Software Foundation; either version |
| 14 | * 2 of the License, or (at your option) any later version. |
| 15 | * |
| 16 | * History |
| 17 | * X.25 001 Jonathan Naylor Started coding. |
| 18 | * X.25 002 Jonathan Naylor Centralised disconnection code. |
| 19 | * New timer architecture. |
YOSHIFUJI Hideaki | f8e1d201 | 2007-02-09 23:25:27 +0900 | [diff] [blame] | 20 | * 2000-03-20 Daniela Squassoni Disabling/enabling of facilities |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 21 | * negotiation. |
| 22 | * 2000-11-10 Henner Eisen Check and reset for out-of-sequence |
| 23 | * i-frames. |
| 24 | */ |
| 25 | |
| 26 | #include <linux/errno.h> |
| 27 | #include <linux/kernel.h> |
| 28 | #include <linux/string.h> |
| 29 | #include <linux/skbuff.h> |
| 30 | #include <net/sock.h> |
Arnaldo Carvalho de Melo | c752f07 | 2005-08-09 20:08:28 -0700 | [diff] [blame] | 31 | #include <net/tcp_states.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | #include <net/x25.h> |
| 33 | |
| 34 | static int x25_queue_rx_frame(struct sock *sk, struct sk_buff *skb, int more) |
| 35 | { |
| 36 | struct sk_buff *skbo, *skbn = skb; |
| 37 | struct x25_sock *x25 = x25_sk(sk); |
| 38 | |
| 39 | if (more) { |
| 40 | x25->fraglen += skb->len; |
| 41 | skb_queue_tail(&x25->fragment_queue, skb); |
| 42 | skb_set_owner_r(skb, sk); |
| 43 | return 0; |
| 44 | } |
| 45 | |
| 46 | if (!more && x25->fraglen > 0) { /* End of fragment */ |
| 47 | int len = x25->fraglen + skb->len; |
| 48 | |
| 49 | if ((skbn = alloc_skb(len, GFP_ATOMIC)) == NULL){ |
| 50 | kfree_skb(skb); |
| 51 | return 1; |
| 52 | } |
| 53 | |
| 54 | skb_queue_tail(&x25->fragment_queue, skb); |
| 55 | |
Arnaldo Carvalho de Melo | badff6d | 2007-03-13 13:06:52 -0300 | [diff] [blame] | 56 | skb_reset_transport_header(skbn); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 57 | |
| 58 | skbo = skb_dequeue(&x25->fragment_queue); |
Arnaldo Carvalho de Melo | 1a4e2d0 | 2007-03-31 11:55:45 -0300 | [diff] [blame] | 59 | skb_copy_from_linear_data(skbo, skb_put(skbn, skbo->len), |
| 60 | skbo->len); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 61 | kfree_skb(skbo); |
| 62 | |
| 63 | while ((skbo = |
| 64 | skb_dequeue(&x25->fragment_queue)) != NULL) { |
| 65 | skb_pull(skbo, (x25->neighbour->extended) ? |
| 66 | X25_EXT_MIN_LEN : X25_STD_MIN_LEN); |
Arnaldo Carvalho de Melo | 1a4e2d0 | 2007-03-31 11:55:45 -0300 | [diff] [blame] | 67 | skb_copy_from_linear_data(skbo, |
| 68 | skb_put(skbn, skbo->len), |
| 69 | skbo->len); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 70 | kfree_skb(skbo); |
| 71 | } |
| 72 | |
YOSHIFUJI Hideaki | f8e1d201 | 2007-02-09 23:25:27 +0900 | [diff] [blame] | 73 | x25->fraglen = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 74 | } |
| 75 | |
| 76 | skb_set_owner_r(skbn, sk); |
| 77 | skb_queue_tail(&sk->sk_receive_queue, skbn); |
| 78 | if (!sock_flag(sk, SOCK_DEAD)) |
| 79 | sk->sk_data_ready(sk, skbn->len); |
| 80 | |
| 81 | return 0; |
| 82 | } |
| 83 | |
| 84 | /* |
| 85 | * State machine for state 1, Awaiting Call Accepted State. |
| 86 | * The handling of the timer(s) is in file x25_timer.c. |
| 87 | * Handling of state 0 and connection release is in af_x25.c. |
| 88 | */ |
| 89 | static int x25_state1_machine(struct sock *sk, struct sk_buff *skb, int frametype) |
| 90 | { |
| 91 | struct x25_address source_addr, dest_addr; |
John Hughes | f5eb917 | 2010-04-07 21:29:25 -0700 | [diff] [blame^] | 92 | int len; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 93 | |
| 94 | switch (frametype) { |
| 95 | case X25_CALL_ACCEPTED: { |
| 96 | struct x25_sock *x25 = x25_sk(sk); |
| 97 | |
| 98 | x25_stop_timer(sk); |
| 99 | x25->condition = 0x00; |
| 100 | x25->vs = 0; |
| 101 | x25->va = 0; |
| 102 | x25->vr = 0; |
| 103 | x25->vl = 0; |
| 104 | x25->state = X25_STATE_3; |
| 105 | sk->sk_state = TCP_ESTABLISHED; |
| 106 | /* |
| 107 | * Parse the data in the frame. |
| 108 | */ |
| 109 | skb_pull(skb, X25_STD_MIN_LEN); |
John Hughes | f5eb917 | 2010-04-07 21:29:25 -0700 | [diff] [blame^] | 110 | |
| 111 | len = x25_parse_address_block(skb, &source_addr, |
| 112 | &dest_addr); |
| 113 | if (len > 0) |
| 114 | skb_pull(skb, len); |
| 115 | |
| 116 | len = x25_parse_facilities(skb, &x25->facilities, |
Shaun Pereira | a64b7b9 | 2006-03-22 00:01:31 -0800 | [diff] [blame] | 117 | &x25->dte_facilities, |
John Hughes | f5eb917 | 2010-04-07 21:29:25 -0700 | [diff] [blame^] | 118 | &x25->vc_facil_mask); |
| 119 | if (len > 0) |
| 120 | skb_pull(skb, len); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 121 | /* |
| 122 | * Copy any Call User Data. |
| 123 | */ |
roel kluin | 091bb8a | 2009-10-23 05:21:56 +0000 | [diff] [blame] | 124 | if (skb->len > 0) { |
Arnaldo Carvalho de Melo | d626f62 | 2007-03-27 18:55:52 -0300 | [diff] [blame] | 125 | skb_copy_from_linear_data(skb, |
| 126 | x25->calluserdata.cuddata, |
| 127 | skb->len); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 128 | x25->calluserdata.cudlength = skb->len; |
| 129 | } |
| 130 | if (!sock_flag(sk, SOCK_DEAD)) |
| 131 | sk->sk_state_change(sk); |
| 132 | break; |
| 133 | } |
| 134 | case X25_CLEAR_REQUEST: |
| 135 | x25_write_internal(sk, X25_CLEAR_CONFIRMATION); |
| 136 | x25_disconnect(sk, ECONNREFUSED, skb->data[3], skb->data[4]); |
| 137 | break; |
| 138 | |
| 139 | default: |
| 140 | break; |
| 141 | } |
| 142 | |
| 143 | return 0; |
| 144 | } |
| 145 | |
| 146 | /* |
| 147 | * State machine for state 2, Awaiting Clear Confirmation State. |
| 148 | * The handling of the timer(s) is in file x25_timer.c |
| 149 | * Handling of state 0 and connection release is in af_x25.c. |
| 150 | */ |
| 151 | static int x25_state2_machine(struct sock *sk, struct sk_buff *skb, int frametype) |
| 152 | { |
| 153 | switch (frametype) { |
| 154 | |
| 155 | case X25_CLEAR_REQUEST: |
| 156 | x25_write_internal(sk, X25_CLEAR_CONFIRMATION); |
| 157 | x25_disconnect(sk, 0, skb->data[3], skb->data[4]); |
| 158 | break; |
| 159 | |
| 160 | case X25_CLEAR_CONFIRMATION: |
| 161 | x25_disconnect(sk, 0, 0, 0); |
| 162 | break; |
| 163 | |
| 164 | default: |
| 165 | break; |
| 166 | } |
| 167 | |
| 168 | return 0; |
| 169 | } |
| 170 | |
| 171 | /* |
| 172 | * State machine for state 3, Connected State. |
| 173 | * The handling of the timer(s) is in file x25_timer.c |
| 174 | * Handling of state 0 and connection release is in af_x25.c. |
| 175 | */ |
| 176 | static int x25_state3_machine(struct sock *sk, struct sk_buff *skb, int frametype, int ns, int nr, int q, int d, int m) |
| 177 | { |
| 178 | int queued = 0; |
| 179 | int modulus; |
| 180 | struct x25_sock *x25 = x25_sk(sk); |
YOSHIFUJI Hideaki | f8e1d201 | 2007-02-09 23:25:27 +0900 | [diff] [blame] | 181 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 182 | modulus = (x25->neighbour->extended) ? X25_EMODULUS : X25_SMODULUS; |
| 183 | |
| 184 | switch (frametype) { |
| 185 | |
| 186 | case X25_RESET_REQUEST: |
| 187 | x25_write_internal(sk, X25_RESET_CONFIRMATION); |
| 188 | x25_stop_timer(sk); |
| 189 | x25->condition = 0x00; |
| 190 | x25->vs = 0; |
| 191 | x25->vr = 0; |
| 192 | x25->va = 0; |
| 193 | x25->vl = 0; |
| 194 | x25_requeue_frames(sk); |
| 195 | break; |
| 196 | |
| 197 | case X25_CLEAR_REQUEST: |
| 198 | x25_write_internal(sk, X25_CLEAR_CONFIRMATION); |
| 199 | x25_disconnect(sk, 0, skb->data[3], skb->data[4]); |
| 200 | break; |
| 201 | |
| 202 | case X25_RR: |
| 203 | case X25_RNR: |
| 204 | if (!x25_validate_nr(sk, nr)) { |
| 205 | x25_clear_queues(sk); |
| 206 | x25_write_internal(sk, X25_RESET_REQUEST); |
| 207 | x25_start_t22timer(sk); |
| 208 | x25->condition = 0x00; |
| 209 | x25->vs = 0; |
| 210 | x25->vr = 0; |
| 211 | x25->va = 0; |
| 212 | x25->vl = 0; |
| 213 | x25->state = X25_STATE_4; |
| 214 | } else { |
| 215 | x25_frames_acked(sk, nr); |
| 216 | if (frametype == X25_RNR) { |
| 217 | x25->condition |= X25_COND_PEER_RX_BUSY; |
| 218 | } else { |
| 219 | x25->condition &= ~X25_COND_PEER_RX_BUSY; |
| 220 | } |
| 221 | } |
| 222 | break; |
| 223 | |
| 224 | case X25_DATA: /* XXX */ |
| 225 | x25->condition &= ~X25_COND_PEER_RX_BUSY; |
| 226 | if ((ns != x25->vr) || !x25_validate_nr(sk, nr)) { |
| 227 | x25_clear_queues(sk); |
| 228 | x25_write_internal(sk, X25_RESET_REQUEST); |
| 229 | x25_start_t22timer(sk); |
| 230 | x25->condition = 0x00; |
| 231 | x25->vs = 0; |
| 232 | x25->vr = 0; |
| 233 | x25->va = 0; |
| 234 | x25->vl = 0; |
| 235 | x25->state = X25_STATE_4; |
| 236 | break; |
| 237 | } |
| 238 | x25_frames_acked(sk, nr); |
| 239 | if (ns == x25->vr) { |
| 240 | if (x25_queue_rx_frame(sk, skb, m) == 0) { |
| 241 | x25->vr = (x25->vr + 1) % modulus; |
| 242 | queued = 1; |
| 243 | } else { |
| 244 | /* Should never happen */ |
| 245 | x25_clear_queues(sk); |
| 246 | x25_write_internal(sk, X25_RESET_REQUEST); |
| 247 | x25_start_t22timer(sk); |
| 248 | x25->condition = 0x00; |
| 249 | x25->vs = 0; |
| 250 | x25->vr = 0; |
| 251 | x25->va = 0; |
| 252 | x25->vl = 0; |
| 253 | x25->state = X25_STATE_4; |
| 254 | break; |
| 255 | } |
| 256 | if (atomic_read(&sk->sk_rmem_alloc) > |
Eric Dumazet | 6bf1574 | 2008-01-13 22:27:52 -0800 | [diff] [blame] | 257 | (sk->sk_rcvbuf >> 1)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 258 | x25->condition |= X25_COND_OWN_RX_BUSY; |
| 259 | } |
| 260 | /* |
| 261 | * If the window is full Ack it immediately, else |
| 262 | * start the holdback timer. |
| 263 | */ |
| 264 | if (((x25->vl + x25->facilities.winsize_in) % modulus) == x25->vr) { |
| 265 | x25->condition &= ~X25_COND_ACK_PENDING; |
| 266 | x25_stop_timer(sk); |
| 267 | x25_enquiry_response(sk); |
| 268 | } else { |
| 269 | x25->condition |= X25_COND_ACK_PENDING; |
| 270 | x25_start_t2timer(sk); |
| 271 | } |
| 272 | break; |
| 273 | |
| 274 | case X25_INTERRUPT_CONFIRMATION: |
| 275 | x25->intflag = 0; |
| 276 | break; |
| 277 | |
| 278 | case X25_INTERRUPT: |
| 279 | if (sock_flag(sk, SOCK_URGINLINE)) |
| 280 | queued = !sock_queue_rcv_skb(sk, skb); |
| 281 | else { |
| 282 | skb_set_owner_r(skb, sk); |
| 283 | skb_queue_tail(&x25->interrupt_in_queue, skb); |
| 284 | queued = 1; |
| 285 | } |
| 286 | sk_send_sigurg(sk); |
| 287 | x25_write_internal(sk, X25_INTERRUPT_CONFIRMATION); |
| 288 | break; |
| 289 | |
| 290 | default: |
| 291 | printk(KERN_WARNING "x25: unknown %02X in state 3\n", frametype); |
| 292 | break; |
| 293 | } |
| 294 | |
| 295 | return queued; |
| 296 | } |
| 297 | |
| 298 | /* |
| 299 | * State machine for state 4, Awaiting Reset Confirmation State. |
| 300 | * The handling of the timer(s) is in file x25_timer.c |
| 301 | * Handling of state 0 and connection release is in af_x25.c. |
| 302 | */ |
| 303 | static int x25_state4_machine(struct sock *sk, struct sk_buff *skb, int frametype) |
| 304 | { |
| 305 | switch (frametype) { |
| 306 | |
| 307 | case X25_RESET_REQUEST: |
| 308 | x25_write_internal(sk, X25_RESET_CONFIRMATION); |
| 309 | case X25_RESET_CONFIRMATION: { |
| 310 | struct x25_sock *x25 = x25_sk(sk); |
| 311 | |
| 312 | x25_stop_timer(sk); |
| 313 | x25->condition = 0x00; |
| 314 | x25->va = 0; |
| 315 | x25->vr = 0; |
| 316 | x25->vs = 0; |
| 317 | x25->vl = 0; |
| 318 | x25->state = X25_STATE_3; |
| 319 | x25_requeue_frames(sk); |
| 320 | break; |
| 321 | } |
| 322 | case X25_CLEAR_REQUEST: |
| 323 | x25_write_internal(sk, X25_CLEAR_CONFIRMATION); |
| 324 | x25_disconnect(sk, 0, skb->data[3], skb->data[4]); |
| 325 | break; |
| 326 | |
| 327 | default: |
| 328 | break; |
| 329 | } |
| 330 | |
| 331 | return 0; |
| 332 | } |
| 333 | |
| 334 | /* Higher level upcall for a LAPB frame */ |
| 335 | int x25_process_rx_frame(struct sock *sk, struct sk_buff *skb) |
| 336 | { |
| 337 | struct x25_sock *x25 = x25_sk(sk); |
| 338 | int queued = 0, frametype, ns, nr, q, d, m; |
| 339 | |
| 340 | if (x25->state == X25_STATE_0) |
| 341 | return 0; |
| 342 | |
| 343 | frametype = x25_decode(sk, skb, &ns, &nr, &q, &d, &m); |
| 344 | |
| 345 | switch (x25->state) { |
| 346 | case X25_STATE_1: |
| 347 | queued = x25_state1_machine(sk, skb, frametype); |
| 348 | break; |
| 349 | case X25_STATE_2: |
| 350 | queued = x25_state2_machine(sk, skb, frametype); |
| 351 | break; |
| 352 | case X25_STATE_3: |
| 353 | queued = x25_state3_machine(sk, skb, frametype, ns, nr, q, d, m); |
| 354 | break; |
| 355 | case X25_STATE_4: |
| 356 | queued = x25_state4_machine(sk, skb, frametype); |
| 357 | break; |
| 358 | } |
| 359 | |
| 360 | x25_kick(sk); |
| 361 | |
| 362 | return queued; |
| 363 | } |
| 364 | |
| 365 | int x25_backlog_rcv(struct sock *sk, struct sk_buff *skb) |
| 366 | { |
| 367 | int queued = x25_process_rx_frame(sk, skb); |
| 368 | |
| 369 | if (!queued) |
| 370 | kfree_skb(skb); |
| 371 | |
| 372 | return 0; |
| 373 | } |