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1da177e4 LT |
1 | /* |
2 | * DECnet An implementation of the DECnet protocol suite for the LINUX | |
3 | * operating system. DECnet is implemented using the BSD Socket | |
4 | * interface as the means of communication with the user level. | |
5 | * | |
6 | * DECnet Network Services Protocol (Input) | |
7 | * | |
8 | * Author: Eduardo Marcelo Serrat <emserrat@geocities.com> | |
9 | * | |
10 | * Changes: | |
11 | * | |
12 | * Steve Whitehouse: Split into dn_nsp_in.c and dn_nsp_out.c from | |
13 | * original dn_nsp.c. | |
14 | * Steve Whitehouse: Updated to work with my new routing architecture. | |
15 | * Steve Whitehouse: Add changes from Eduardo Serrat's patches. | |
16 | * Steve Whitehouse: Put all ack handling code in a common routine. | |
17 | * Steve Whitehouse: Put other common bits into dn_nsp_rx() | |
18 | * Steve Whitehouse: More checks on skb->len to catch bogus packets | |
19 | * Fixed various race conditions and possible nasties. | |
20 | * Steve Whitehouse: Now handles returned conninit frames. | |
21 | * David S. Miller: New socket locking | |
22 | * Steve Whitehouse: Fixed lockup when socket filtering was enabled. | |
23 | * Paul Koning: Fix to push CC sockets into RUN when acks are | |
24 | * received. | |
25 | * Steve Whitehouse: | |
26 | * Patrick Caulfield: Checking conninits for correctness & sending of error | |
27 | * responses. | |
28 | * Steve Whitehouse: Added backlog congestion level return codes. | |
29 | * Patrick Caulfield: | |
30 | * Steve Whitehouse: Added flow control support (outbound) | |
31 | * Steve Whitehouse: Prepare for nonlinear skbs | |
32 | */ | |
33 | ||
34 | /****************************************************************************** | |
35 | (c) 1995-1998 E.M. Serrat emserrat@geocities.com | |
429eb0fa | 36 | |
1da177e4 LT |
37 | This program is free software; you can redistribute it and/or modify |
38 | it under the terms of the GNU General Public License as published by | |
39 | the Free Software Foundation; either version 2 of the License, or | |
40 | any later version. | |
41 | ||
42 | This program is distributed in the hope that it will be useful, | |
43 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
44 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
45 | GNU General Public License for more details. | |
46 | *******************************************************************************/ | |
47 | ||
1da177e4 LT |
48 | #include <linux/errno.h> |
49 | #include <linux/types.h> | |
50 | #include <linux/socket.h> | |
51 | #include <linux/in.h> | |
52 | #include <linux/kernel.h> | |
1da177e4 LT |
53 | #include <linux/timer.h> |
54 | #include <linux/string.h> | |
55 | #include <linux/sockios.h> | |
56 | #include <linux/net.h> | |
57 | #include <linux/netdevice.h> | |
58 | #include <linux/inet.h> | |
59 | #include <linux/route.h> | |
60 | #include <net/sock.h> | |
c752f073 | 61 | #include <net/tcp_states.h> |
1da177e4 LT |
62 | #include <asm/system.h> |
63 | #include <linux/fcntl.h> | |
64 | #include <linux/mm.h> | |
429eb0fa | 65 | #include <linux/termios.h> |
1da177e4 LT |
66 | #include <linux/interrupt.h> |
67 | #include <linux/proc_fs.h> | |
68 | #include <linux/stat.h> | |
69 | #include <linux/init.h> | |
70 | #include <linux/poll.h> | |
71 | #include <linux/netfilter_decnet.h> | |
72 | #include <net/neighbour.h> | |
73 | #include <net/dst.h> | |
74 | #include <net/dn.h> | |
75 | #include <net/dn_nsp.h> | |
76 | #include <net/dn_dev.h> | |
77 | #include <net/dn_route.h> | |
78 | ||
79 | extern int decnet_log_martians; | |
80 | ||
81 | static void dn_log_martian(struct sk_buff *skb, const char *msg) | |
82 | { | |
83 | if (decnet_log_martians && net_ratelimit()) { | |
84 | char *devname = skb->dev ? skb->dev->name : "???"; | |
85 | struct dn_skb_cb *cb = DN_SKB_CB(skb); | |
c4106aa8 HH |
86 | printk(KERN_INFO "DECnet: Martian packet (%s) dev=%s src=0x%04hx dst=0x%04hx srcport=0x%04hx dstport=0x%04hx\n", |
87 | msg, devname, le16_to_cpu(cb->src), le16_to_cpu(cb->dst), | |
88 | le16_to_cpu(cb->src_port), le16_to_cpu(cb->dst_port)); | |
1da177e4 LT |
89 | } |
90 | } | |
91 | ||
92 | /* | |
93 | * For this function we've flipped the cross-subchannel bit | |
94 | * if the message is an otherdata or linkservice message. Thus | |
95 | * we can use it to work out what to update. | |
96 | */ | |
97 | static void dn_ack(struct sock *sk, struct sk_buff *skb, unsigned short ack) | |
98 | { | |
99 | struct dn_scp *scp = DN_SK(sk); | |
100 | unsigned short type = ((ack >> 12) & 0x0003); | |
101 | int wakeup = 0; | |
102 | ||
103 | switch(type) { | |
104 | case 0: /* ACK - Data */ | |
105 | if (dn_after(ack, scp->ackrcv_dat)) { | |
106 | scp->ackrcv_dat = ack & 0x0fff; | |
107 | wakeup |= dn_nsp_check_xmit_queue(sk, skb, &scp->data_xmit_queue, ack); | |
108 | } | |
109 | break; | |
110 | case 1: /* NAK - Data */ | |
111 | break; | |
112 | case 2: /* ACK - OtherData */ | |
113 | if (dn_after(ack, scp->ackrcv_oth)) { | |
114 | scp->ackrcv_oth = ack & 0x0fff; | |
115 | wakeup |= dn_nsp_check_xmit_queue(sk, skb, &scp->other_xmit_queue, ack); | |
116 | } | |
117 | break; | |
118 | case 3: /* NAK - OtherData */ | |
119 | break; | |
120 | } | |
121 | ||
122 | if (wakeup && !sock_flag(sk, SOCK_DEAD)) | |
123 | sk->sk_state_change(sk); | |
124 | } | |
125 | ||
126 | /* | |
127 | * This function is a universal ack processor. | |
128 | */ | |
129 | static int dn_process_ack(struct sock *sk, struct sk_buff *skb, int oth) | |
130 | { | |
c4ea94ab | 131 | __le16 *ptr = (__le16 *)skb->data; |
1da177e4 LT |
132 | int len = 0; |
133 | unsigned short ack; | |
134 | ||
135 | if (skb->len < 2) | |
136 | return len; | |
137 | ||
c4106aa8 | 138 | if ((ack = le16_to_cpu(*ptr)) & 0x8000) { |
1da177e4 LT |
139 | skb_pull(skb, 2); |
140 | ptr++; | |
141 | len += 2; | |
142 | if ((ack & 0x4000) == 0) { | |
429eb0fa | 143 | if (oth) |
1da177e4 LT |
144 | ack ^= 0x2000; |
145 | dn_ack(sk, skb, ack); | |
146 | } | |
147 | } | |
148 | ||
149 | if (skb->len < 2) | |
150 | return len; | |
151 | ||
c4106aa8 | 152 | if ((ack = le16_to_cpu(*ptr)) & 0x8000) { |
1da177e4 LT |
153 | skb_pull(skb, 2); |
154 | len += 2; | |
155 | if ((ack & 0x4000) == 0) { | |
429eb0fa | 156 | if (oth) |
1da177e4 LT |
157 | ack ^= 0x2000; |
158 | dn_ack(sk, skb, ack); | |
159 | } | |
160 | } | |
161 | ||
162 | return len; | |
163 | } | |
164 | ||
165 | ||
166 | /** | |
167 | * dn_check_idf - Check an image data field format is correct. | |
168 | * @pptr: Pointer to pointer to image data | |
169 | * @len: Pointer to length of image data | |
170 | * @max: The maximum allowed length of the data in the image data field | |
171 | * @follow_on: Check that this many bytes exist beyond the end of the image data | |
172 | * | |
173 | * Returns: 0 if ok, -1 on error | |
174 | */ | |
175 | static inline int dn_check_idf(unsigned char **pptr, int *len, unsigned char max, unsigned char follow_on) | |
176 | { | |
177 | unsigned char *ptr = *pptr; | |
178 | unsigned char flen = *ptr++; | |
179 | ||
180 | (*len)--; | |
181 | if (flen > max) | |
182 | return -1; | |
183 | if ((flen + follow_on) > *len) | |
184 | return -1; | |
185 | ||
186 | *len -= flen; | |
187 | *pptr = ptr + flen; | |
188 | return 0; | |
189 | } | |
190 | ||
191 | /* | |
192 | * Table of reason codes to pass back to node which sent us a badly | |
193 | * formed message, plus text messages for the log. A zero entry in | |
194 | * the reason field means "don't reply" otherwise a disc init is sent with | |
195 | * the specified reason code. | |
196 | */ | |
197 | static struct { | |
198 | unsigned short reason; | |
199 | const char *text; | |
200 | } ci_err_table[] = { | |
201 | { 0, "CI: Truncated message" }, | |
202 | { NSP_REASON_ID, "CI: Destination username error" }, | |
203 | { NSP_REASON_ID, "CI: Destination username type" }, | |
204 | { NSP_REASON_US, "CI: Source username error" }, | |
205 | { 0, "CI: Truncated at menuver" }, | |
206 | { 0, "CI: Truncated before access or user data" }, | |
207 | { NSP_REASON_IO, "CI: Access data format error" }, | |
208 | { NSP_REASON_IO, "CI: User data format error" } | |
209 | }; | |
210 | ||
211 | /* | |
212 | * This function uses a slightly different lookup method | |
213 | * to find its sockets, since it searches on object name/number | |
214 | * rather than port numbers. Various tests are done to ensure that | |
215 | * the incoming data is in the correct format before it is queued to | |
216 | * a socket. | |
217 | */ | |
218 | static struct sock *dn_find_listener(struct sk_buff *skb, unsigned short *reason) | |
219 | { | |
220 | struct dn_skb_cb *cb = DN_SKB_CB(skb); | |
221 | struct nsp_conn_init_msg *msg = (struct nsp_conn_init_msg *)skb->data; | |
222 | struct sockaddr_dn dstaddr; | |
223 | struct sockaddr_dn srcaddr; | |
224 | unsigned char type = 0; | |
225 | int dstlen; | |
226 | int srclen; | |
227 | unsigned char *ptr; | |
228 | int len; | |
229 | int err = 0; | |
230 | unsigned char menuver; | |
231 | ||
232 | memset(&dstaddr, 0, sizeof(struct sockaddr_dn)); | |
233 | memset(&srcaddr, 0, sizeof(struct sockaddr_dn)); | |
234 | ||
235 | /* | |
236 | * 1. Decode & remove message header | |
237 | */ | |
238 | cb->src_port = msg->srcaddr; | |
239 | cb->dst_port = msg->dstaddr; | |
240 | cb->services = msg->services; | |
241 | cb->info = msg->info; | |
c4106aa8 | 242 | cb->segsize = le16_to_cpu(msg->segsize); |
1da177e4 LT |
243 | |
244 | if (!pskb_may_pull(skb, sizeof(*msg))) | |
245 | goto err_out; | |
246 | ||
247 | skb_pull(skb, sizeof(*msg)); | |
248 | ||
249 | len = skb->len; | |
250 | ptr = skb->data; | |
251 | ||
252 | /* | |
253 | * 2. Check destination end username format | |
254 | */ | |
255 | dstlen = dn_username2sockaddr(ptr, len, &dstaddr, &type); | |
256 | err++; | |
257 | if (dstlen < 0) | |
258 | goto err_out; | |
259 | ||
260 | err++; | |
261 | if (type > 1) | |
262 | goto err_out; | |
263 | ||
264 | len -= dstlen; | |
265 | ptr += dstlen; | |
266 | ||
267 | /* | |
268 | * 3. Check source end username format | |
269 | */ | |
270 | srclen = dn_username2sockaddr(ptr, len, &srcaddr, &type); | |
271 | err++; | |
272 | if (srclen < 0) | |
273 | goto err_out; | |
274 | ||
275 | len -= srclen; | |
276 | ptr += srclen; | |
277 | err++; | |
278 | if (len < 1) | |
279 | goto err_out; | |
280 | ||
281 | menuver = *ptr; | |
282 | ptr++; | |
283 | len--; | |
284 | ||
285 | /* | |
286 | * 4. Check that optional data actually exists if menuver says it does | |
287 | */ | |
288 | err++; | |
289 | if ((menuver & (DN_MENUVER_ACC | DN_MENUVER_USR)) && (len < 1)) | |
290 | goto err_out; | |
291 | ||
292 | /* | |
293 | * 5. Check optional access data format | |
294 | */ | |
295 | err++; | |
296 | if (menuver & DN_MENUVER_ACC) { | |
297 | if (dn_check_idf(&ptr, &len, 39, 1)) | |
298 | goto err_out; | |
299 | if (dn_check_idf(&ptr, &len, 39, 1)) | |
300 | goto err_out; | |
301 | if (dn_check_idf(&ptr, &len, 39, (menuver & DN_MENUVER_USR) ? 1 : 0)) | |
302 | goto err_out; | |
303 | } | |
304 | ||
305 | /* | |
306 | * 6. Check optional user data format | |
307 | */ | |
308 | err++; | |
309 | if (menuver & DN_MENUVER_USR) { | |
310 | if (dn_check_idf(&ptr, &len, 16, 0)) | |
311 | goto err_out; | |
312 | } | |
313 | ||
314 | /* | |
315 | * 7. Look up socket based on destination end username | |
316 | */ | |
317 | return dn_sklist_find_listener(&dstaddr); | |
318 | err_out: | |
319 | dn_log_martian(skb, ci_err_table[err].text); | |
320 | *reason = ci_err_table[err].reason; | |
321 | return NULL; | |
322 | } | |
323 | ||
324 | ||
325 | static void dn_nsp_conn_init(struct sock *sk, struct sk_buff *skb) | |
326 | { | |
327 | if (sk_acceptq_is_full(sk)) { | |
328 | kfree_skb(skb); | |
329 | return; | |
330 | } | |
331 | ||
332 | sk->sk_ack_backlog++; | |
333 | skb_queue_tail(&sk->sk_receive_queue, skb); | |
334 | sk->sk_state_change(sk); | |
335 | } | |
336 | ||
337 | static void dn_nsp_conn_conf(struct sock *sk, struct sk_buff *skb) | |
338 | { | |
339 | struct dn_skb_cb *cb = DN_SKB_CB(skb); | |
340 | struct dn_scp *scp = DN_SK(sk); | |
341 | unsigned char *ptr; | |
342 | ||
343 | if (skb->len < 4) | |
344 | goto out; | |
345 | ||
346 | ptr = skb->data; | |
347 | cb->services = *ptr++; | |
348 | cb->info = *ptr++; | |
c4106aa8 | 349 | cb->segsize = le16_to_cpu(*(__le16 *)ptr); |
1da177e4 LT |
350 | |
351 | if ((scp->state == DN_CI) || (scp->state == DN_CD)) { | |
352 | scp->persist = 0; | |
429eb0fa YH |
353 | scp->addrrem = cb->src_port; |
354 | sk->sk_state = TCP_ESTABLISHED; | |
355 | scp->state = DN_RUN; | |
1da177e4 LT |
356 | scp->services_rem = cb->services; |
357 | scp->info_rem = cb->info; | |
358 | scp->segsize_rem = cb->segsize; | |
359 | ||
360 | if ((scp->services_rem & NSP_FC_MASK) == NSP_FC_NONE) | |
361 | scp->max_window = decnet_no_fc_max_cwnd; | |
362 | ||
363 | if (skb->len > 0) { | |
375d9d71 | 364 | u16 dlen = *skb->data; |
1da177e4 | 365 | if ((dlen <= 16) && (dlen <= skb->len)) { |
c4106aa8 | 366 | scp->conndata_in.opt_optl = cpu_to_le16(dlen); |
d626f62b ACM |
367 | skb_copy_from_linear_data_offset(skb, 1, |
368 | scp->conndata_in.opt_data, dlen); | |
1da177e4 LT |
369 | } |
370 | } | |
429eb0fa YH |
371 | dn_nsp_send_link(sk, DN_NOCHANGE, 0); |
372 | if (!sock_flag(sk, SOCK_DEAD)) | |
373 | sk->sk_state_change(sk); | |
374 | } | |
1da177e4 LT |
375 | |
376 | out: | |
429eb0fa | 377 | kfree_skb(skb); |
1da177e4 LT |
378 | } |
379 | ||
380 | static void dn_nsp_conn_ack(struct sock *sk, struct sk_buff *skb) | |
381 | { | |
382 | struct dn_scp *scp = DN_SK(sk); | |
383 | ||
384 | if (scp->state == DN_CI) { | |
385 | scp->state = DN_CD; | |
386 | scp->persist = 0; | |
387 | } | |
388 | ||
389 | kfree_skb(skb); | |
390 | } | |
391 | ||
392 | static void dn_nsp_disc_init(struct sock *sk, struct sk_buff *skb) | |
393 | { | |
394 | struct dn_scp *scp = DN_SK(sk); | |
395 | struct dn_skb_cb *cb = DN_SKB_CB(skb); | |
396 | unsigned short reason; | |
397 | ||
398 | if (skb->len < 2) | |
399 | goto out; | |
400 | ||
c4106aa8 | 401 | reason = le16_to_cpu(*(__le16 *)skb->data); |
1da177e4 LT |
402 | skb_pull(skb, 2); |
403 | ||
c4106aa8 | 404 | scp->discdata_in.opt_status = cpu_to_le16(reason); |
1da177e4 LT |
405 | scp->discdata_in.opt_optl = 0; |
406 | memset(scp->discdata_in.opt_data, 0, 16); | |
407 | ||
408 | if (skb->len > 0) { | |
375d9d71 | 409 | u16 dlen = *skb->data; |
1da177e4 | 410 | if ((dlen <= 16) && (dlen <= skb->len)) { |
c4106aa8 | 411 | scp->discdata_in.opt_optl = cpu_to_le16(dlen); |
d626f62b | 412 | skb_copy_from_linear_data_offset(skb, 1, scp->discdata_in.opt_data, dlen); |
1da177e4 LT |
413 | } |
414 | } | |
415 | ||
416 | scp->addrrem = cb->src_port; | |
417 | sk->sk_state = TCP_CLOSE; | |
418 | ||
419 | switch(scp->state) { | |
420 | case DN_CI: | |
421 | case DN_CD: | |
422 | scp->state = DN_RJ; | |
423 | sk->sk_err = ECONNREFUSED; | |
424 | break; | |
425 | case DN_RUN: | |
426 | sk->sk_shutdown |= SHUTDOWN_MASK; | |
427 | scp->state = DN_DN; | |
428 | break; | |
429 | case DN_DI: | |
430 | scp->state = DN_DIC; | |
431 | break; | |
432 | } | |
433 | ||
434 | if (!sock_flag(sk, SOCK_DEAD)) { | |
435 | if (sk->sk_socket->state != SS_UNCONNECTED) | |
436 | sk->sk_socket->state = SS_DISCONNECTING; | |
437 | sk->sk_state_change(sk); | |
438 | } | |
439 | ||
429eb0fa | 440 | /* |
1da177e4 LT |
441 | * It appears that its possible for remote machines to send disc |
442 | * init messages with no port identifier if we are in the CI and | |
443 | * possibly also the CD state. Obviously we shouldn't reply with | |
444 | * a message if we don't know what the end point is. | |
445 | */ | |
446 | if (scp->addrrem) { | |
447 | dn_nsp_send_disc(sk, NSP_DISCCONF, NSP_REASON_DC, GFP_ATOMIC); | |
448 | } | |
449 | scp->persist_fxn = dn_destroy_timer; | |
450 | scp->persist = dn_nsp_persist(sk); | |
451 | ||
452 | out: | |
453 | kfree_skb(skb); | |
454 | } | |
455 | ||
456 | /* | |
457 | * disc_conf messages are also called no_resources or no_link | |
458 | * messages depending upon the "reason" field. | |
459 | */ | |
460 | static void dn_nsp_disc_conf(struct sock *sk, struct sk_buff *skb) | |
461 | { | |
462 | struct dn_scp *scp = DN_SK(sk); | |
463 | unsigned short reason; | |
464 | ||
465 | if (skb->len != 2) | |
466 | goto out; | |
467 | ||
c4106aa8 | 468 | reason = le16_to_cpu(*(__le16 *)skb->data); |
1da177e4 LT |
469 | |
470 | sk->sk_state = TCP_CLOSE; | |
471 | ||
472 | switch(scp->state) { | |
473 | case DN_CI: | |
474 | scp->state = DN_NR; | |
475 | break; | |
476 | case DN_DR: | |
477 | if (reason == NSP_REASON_DC) | |
478 | scp->state = DN_DRC; | |
479 | if (reason == NSP_REASON_NL) | |
480 | scp->state = DN_CN; | |
481 | break; | |
482 | case DN_DI: | |
483 | scp->state = DN_DIC; | |
484 | break; | |
485 | case DN_RUN: | |
486 | sk->sk_shutdown |= SHUTDOWN_MASK; | |
487 | case DN_CC: | |
488 | scp->state = DN_CN; | |
489 | } | |
490 | ||
491 | if (!sock_flag(sk, SOCK_DEAD)) { | |
492 | if (sk->sk_socket->state != SS_UNCONNECTED) | |
493 | sk->sk_socket->state = SS_DISCONNECTING; | |
494 | sk->sk_state_change(sk); | |
495 | } | |
496 | ||
497 | scp->persist_fxn = dn_destroy_timer; | |
498 | scp->persist = dn_nsp_persist(sk); | |
499 | ||
500 | out: | |
501 | kfree_skb(skb); | |
502 | } | |
503 | ||
504 | static void dn_nsp_linkservice(struct sock *sk, struct sk_buff *skb) | |
505 | { | |
506 | struct dn_scp *scp = DN_SK(sk); | |
507 | unsigned short segnum; | |
508 | unsigned char lsflags; | |
509 | signed char fcval; | |
510 | int wake_up = 0; | |
511 | char *ptr = skb->data; | |
512 | unsigned char fctype = scp->services_rem & NSP_FC_MASK; | |
513 | ||
514 | if (skb->len != 4) | |
515 | goto out; | |
516 | ||
c4106aa8 | 517 | segnum = le16_to_cpu(*(__le16 *)ptr); |
1da177e4 LT |
518 | ptr += 2; |
519 | lsflags = *(unsigned char *)ptr++; | |
520 | fcval = *ptr; | |
521 | ||
522 | /* | |
523 | * Here we ignore erronous packets which should really | |
429eb0fa | 524 | * should cause a connection abort. It is not critical |
1da177e4 LT |
525 | * for now though. |
526 | */ | |
527 | if (lsflags & 0xf8) | |
528 | goto out; | |
529 | ||
530 | if (seq_next(scp->numoth_rcv, segnum)) { | |
531 | seq_add(&scp->numoth_rcv, 1); | |
532 | switch(lsflags & 0x04) { /* FCVAL INT */ | |
533 | case 0x00: /* Normal Request */ | |
534 | switch(lsflags & 0x03) { /* FCVAL MOD */ | |
429eb0fa | 535 | case 0x00: /* Request count */ |
1da177e4 LT |
536 | if (fcval < 0) { |
537 | unsigned char p_fcval = -fcval; | |
538 | if ((scp->flowrem_dat > p_fcval) && | |
539 | (fctype == NSP_FC_SCMC)) { | |
540 | scp->flowrem_dat -= p_fcval; | |
541 | } | |
542 | } else if (fcval > 0) { | |
543 | scp->flowrem_dat += fcval; | |
544 | wake_up = 1; | |
545 | } | |
429eb0fa | 546 | break; |
1da177e4 LT |
547 | case 0x01: /* Stop outgoing data */ |
548 | scp->flowrem_sw = DN_DONTSEND; | |
549 | break; | |
550 | case 0x02: /* Ok to start again */ | |
551 | scp->flowrem_sw = DN_SEND; | |
552 | dn_nsp_output(sk); | |
553 | wake_up = 1; | |
554 | } | |
555 | break; | |
556 | case 0x04: /* Interrupt Request */ | |
557 | if (fcval > 0) { | |
558 | scp->flowrem_oth += fcval; | |
559 | wake_up = 1; | |
560 | } | |
561 | break; | |
429eb0fa | 562 | } |
1da177e4 LT |
563 | if (wake_up && !sock_flag(sk, SOCK_DEAD)) |
564 | sk->sk_state_change(sk); | |
429eb0fa | 565 | } |
1da177e4 LT |
566 | |
567 | dn_nsp_send_oth_ack(sk); | |
568 | ||
569 | out: | |
570 | kfree_skb(skb); | |
571 | } | |
572 | ||
573 | /* | |
574 | * Copy of sock_queue_rcv_skb (from sock.h) without | |
575 | * bh_lock_sock() (its already held when this is called) which | |
576 | * also allows data and other data to be queued to a socket. | |
577 | */ | |
578 | static __inline__ int dn_queue_skb(struct sock *sk, struct sk_buff *skb, int sig, struct sk_buff_head *queue) | |
579 | { | |
580 | int err; | |
9948bb6a | 581 | int skb_len; |
429eb0fa YH |
582 | |
583 | /* Cast skb->rcvbuf to unsigned... It's pointless, but reduces | |
584 | number of warnings when compiling with -W --ANK | |
585 | */ | |
586 | if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >= | |
1da177e4 | 587 | (unsigned)sk->sk_rcvbuf) { |
429eb0fa YH |
588 | err = -ENOMEM; |
589 | goto out; | |
590 | } | |
1da177e4 | 591 | |
fda9ef5d | 592 | err = sk_filter(sk, skb); |
1da177e4 LT |
593 | if (err) |
594 | goto out; | |
595 | ||
9948bb6a | 596 | skb_len = skb->len; |
429eb0fa YH |
597 | skb_set_owner_r(skb, sk); |
598 | skb_queue_tail(queue, skb); | |
1da177e4 | 599 | |
9948bb6a SW |
600 | if (!sock_flag(sk, SOCK_DEAD)) |
601 | sk->sk_data_ready(sk, skb_len); | |
1da177e4 | 602 | out: |
429eb0fa | 603 | return err; |
1da177e4 LT |
604 | } |
605 | ||
606 | static void dn_nsp_otherdata(struct sock *sk, struct sk_buff *skb) | |
607 | { | |
608 | struct dn_scp *scp = DN_SK(sk); | |
609 | unsigned short segnum; | |
610 | struct dn_skb_cb *cb = DN_SKB_CB(skb); | |
611 | int queued = 0; | |
612 | ||
613 | if (skb->len < 2) | |
614 | goto out; | |
615 | ||
c4106aa8 | 616 | cb->segnum = segnum = le16_to_cpu(*(__le16 *)skb->data); |
1da177e4 LT |
617 | skb_pull(skb, 2); |
618 | ||
619 | if (seq_next(scp->numoth_rcv, segnum)) { | |
620 | ||
621 | if (dn_queue_skb(sk, skb, SIGURG, &scp->other_receive_queue) == 0) { | |
622 | seq_add(&scp->numoth_rcv, 1); | |
623 | scp->other_report = 0; | |
624 | queued = 1; | |
625 | } | |
626 | } | |
627 | ||
628 | dn_nsp_send_oth_ack(sk); | |
629 | out: | |
630 | if (!queued) | |
631 | kfree_skb(skb); | |
632 | } | |
633 | ||
634 | static void dn_nsp_data(struct sock *sk, struct sk_buff *skb) | |
635 | { | |
636 | int queued = 0; | |
637 | unsigned short segnum; | |
638 | struct dn_skb_cb *cb = DN_SKB_CB(skb); | |
639 | struct dn_scp *scp = DN_SK(sk); | |
640 | ||
641 | if (skb->len < 2) | |
642 | goto out; | |
643 | ||
c4106aa8 | 644 | cb->segnum = segnum = le16_to_cpu(*(__le16 *)skb->data); |
1da177e4 LT |
645 | skb_pull(skb, 2); |
646 | ||
647 | if (seq_next(scp->numdat_rcv, segnum)) { | |
429eb0fa | 648 | if (dn_queue_skb(sk, skb, SIGIO, &sk->sk_receive_queue) == 0) { |
1da177e4 | 649 | seq_add(&scp->numdat_rcv, 1); |
429eb0fa YH |
650 | queued = 1; |
651 | } | |
1da177e4 LT |
652 | |
653 | if ((scp->flowloc_sw == DN_SEND) && dn_congested(sk)) { | |
654 | scp->flowloc_sw = DN_DONTSEND; | |
655 | dn_nsp_send_link(sk, DN_DONTSEND, 0); | |
656 | } | |
429eb0fa | 657 | } |
1da177e4 LT |
658 | |
659 | dn_nsp_send_data_ack(sk); | |
660 | out: | |
661 | if (!queued) | |
662 | kfree_skb(skb); | |
663 | } | |
664 | ||
665 | /* | |
666 | * If one of our conninit messages is returned, this function | |
667 | * deals with it. It puts the socket into the NO_COMMUNICATION | |
668 | * state. | |
669 | */ | |
670 | static void dn_returned_conn_init(struct sock *sk, struct sk_buff *skb) | |
671 | { | |
672 | struct dn_scp *scp = DN_SK(sk); | |
673 | ||
674 | if (scp->state == DN_CI) { | |
675 | scp->state = DN_NC; | |
676 | sk->sk_state = TCP_CLOSE; | |
677 | if (!sock_flag(sk, SOCK_DEAD)) | |
678 | sk->sk_state_change(sk); | |
679 | } | |
680 | ||
681 | kfree_skb(skb); | |
682 | } | |
683 | ||
684 | static int dn_nsp_no_socket(struct sk_buff *skb, unsigned short reason) | |
685 | { | |
686 | struct dn_skb_cb *cb = DN_SKB_CB(skb); | |
687 | int ret = NET_RX_DROP; | |
688 | ||
689 | /* Must not reply to returned packets */ | |
690 | if (cb->rt_flags & DN_RT_F_RTS) | |
691 | goto out; | |
692 | ||
693 | if ((reason != NSP_REASON_OK) && ((cb->nsp_flags & 0x0c) == 0x08)) { | |
694 | switch(cb->nsp_flags & 0x70) { | |
695 | case 0x10: | |
696 | case 0x60: /* (Retransmitted) Connect Init */ | |
697 | dn_nsp_return_disc(skb, NSP_DISCINIT, reason); | |
698 | ret = NET_RX_SUCCESS; | |
699 | break; | |
700 | case 0x20: /* Connect Confirm */ | |
701 | dn_nsp_return_disc(skb, NSP_DISCCONF, reason); | |
702 | ret = NET_RX_SUCCESS; | |
703 | break; | |
704 | } | |
705 | } | |
706 | ||
707 | out: | |
708 | kfree_skb(skb); | |
709 | return ret; | |
710 | } | |
711 | ||
712 | static int dn_nsp_rx_packet(struct sk_buff *skb) | |
713 | { | |
714 | struct dn_skb_cb *cb = DN_SKB_CB(skb); | |
715 | struct sock *sk = NULL; | |
716 | unsigned char *ptr = (unsigned char *)skb->data; | |
717 | unsigned short reason = NSP_REASON_NL; | |
718 | ||
719 | if (!pskb_may_pull(skb, 2)) | |
720 | goto free_out; | |
721 | ||
badff6d0 | 722 | skb_reset_transport_header(skb); |
1da177e4 LT |
723 | cb->nsp_flags = *ptr++; |
724 | ||
725 | if (decnet_debug_level & 2) | |
726 | printk(KERN_DEBUG "dn_nsp_rx: Message type 0x%02x\n", (int)cb->nsp_flags); | |
727 | ||
429eb0fa | 728 | if (cb->nsp_flags & 0x83) |
1da177e4 LT |
729 | goto free_out; |
730 | ||
731 | /* | |
732 | * Filter out conninits and useless packet types | |
733 | */ | |
734 | if ((cb->nsp_flags & 0x0c) == 0x08) { | |
735 | switch(cb->nsp_flags & 0x70) { | |
736 | case 0x00: /* NOP */ | |
737 | case 0x70: /* Reserved */ | |
738 | case 0x50: /* Reserved, Phase II node init */ | |
739 | goto free_out; | |
740 | case 0x10: | |
741 | case 0x60: | |
742 | if (unlikely(cb->rt_flags & DN_RT_F_RTS)) | |
743 | goto free_out; | |
744 | sk = dn_find_listener(skb, &reason); | |
745 | goto got_it; | |
746 | } | |
747 | } | |
748 | ||
749 | if (!pskb_may_pull(skb, 3)) | |
750 | goto free_out; | |
751 | ||
752 | /* | |
753 | * Grab the destination address. | |
754 | */ | |
c4ea94ab | 755 | cb->dst_port = *(__le16 *)ptr; |
1da177e4 LT |
756 | cb->src_port = 0; |
757 | ptr += 2; | |
758 | ||
759 | /* | |
760 | * If not a connack, grab the source address too. | |
761 | */ | |
762 | if (pskb_may_pull(skb, 5)) { | |
c4ea94ab | 763 | cb->src_port = *(__le16 *)ptr; |
1da177e4 LT |
764 | ptr += 2; |
765 | skb_pull(skb, 5); | |
766 | } | |
767 | ||
768 | /* | |
769 | * Returned packets... | |
770 | * Swap src & dst and look up in the normal way. | |
771 | */ | |
772 | if (unlikely(cb->rt_flags & DN_RT_F_RTS)) { | |
c4ea94ab | 773 | __le16 tmp = cb->dst_port; |
1da177e4 LT |
774 | cb->dst_port = cb->src_port; |
775 | cb->src_port = tmp; | |
776 | tmp = cb->dst; | |
777 | cb->dst = cb->src; | |
778 | cb->src = tmp; | |
779 | } | |
780 | ||
781 | /* | |
782 | * Find the socket to which this skb is destined. | |
783 | */ | |
784 | sk = dn_find_by_skb(skb); | |
785 | got_it: | |
786 | if (sk != NULL) { | |
787 | struct dn_scp *scp = DN_SK(sk); | |
1da177e4 LT |
788 | |
789 | /* Reset backoff */ | |
790 | scp->nsp_rxtshift = 0; | |
791 | ||
792 | /* | |
793 | * We linearize everything except data segments here. | |
794 | */ | |
795 | if (cb->nsp_flags & ~0x60) { | |
364c6bad | 796 | if (unlikely(skb_linearize(skb))) |
1da177e4 LT |
797 | goto free_out; |
798 | } | |
799 | ||
58a5a7b9 | 800 | return sk_receive_skb(sk, skb, 0); |
1da177e4 LT |
801 | } |
802 | ||
803 | return dn_nsp_no_socket(skb, reason); | |
804 | ||
805 | free_out: | |
806 | kfree_skb(skb); | |
807 | return NET_RX_DROP; | |
808 | } | |
809 | ||
810 | int dn_nsp_rx(struct sk_buff *skb) | |
811 | { | |
812 | return NF_HOOK(PF_DECnet, NF_DN_LOCAL_IN, skb, skb->dev, NULL, dn_nsp_rx_packet); | |
813 | } | |
814 | ||
815 | /* | |
816 | * This is the main receive routine for sockets. It is called | |
817 | * from the above when the socket is not busy, and also from | |
818 | * sock_release() when there is a backlog queued up. | |
819 | */ | |
820 | int dn_nsp_backlog_rcv(struct sock *sk, struct sk_buff *skb) | |
821 | { | |
822 | struct dn_scp *scp = DN_SK(sk); | |
823 | struct dn_skb_cb *cb = DN_SKB_CB(skb); | |
824 | ||
825 | if (cb->rt_flags & DN_RT_F_RTS) { | |
826 | if (cb->nsp_flags == 0x18 || cb->nsp_flags == 0x68) | |
827 | dn_returned_conn_init(sk, skb); | |
828 | else | |
829 | kfree_skb(skb); | |
830 | return NET_RX_SUCCESS; | |
831 | } | |
832 | ||
833 | /* | |
834 | * Control packet. | |
835 | */ | |
836 | if ((cb->nsp_flags & 0x0c) == 0x08) { | |
837 | switch(cb->nsp_flags & 0x70) { | |
838 | case 0x10: | |
839 | case 0x60: | |
840 | dn_nsp_conn_init(sk, skb); | |
841 | break; | |
842 | case 0x20: | |
843 | dn_nsp_conn_conf(sk, skb); | |
844 | break; | |
845 | case 0x30: | |
846 | dn_nsp_disc_init(sk, skb); | |
847 | break; | |
429eb0fa | 848 | case 0x40: |
1da177e4 LT |
849 | dn_nsp_disc_conf(sk, skb); |
850 | break; | |
851 | } | |
852 | ||
853 | } else if (cb->nsp_flags == 0x24) { | |
854 | /* | |
855 | * Special for connacks, 'cos they don't have | |
856 | * ack data or ack otherdata info. | |
857 | */ | |
858 | dn_nsp_conn_ack(sk, skb); | |
859 | } else { | |
860 | int other = 1; | |
861 | ||
862 | /* both data and ack frames can kick a CC socket into RUN */ | |
863 | if ((scp->state == DN_CC) && !sock_flag(sk, SOCK_DEAD)) { | |
864 | scp->state = DN_RUN; | |
865 | sk->sk_state = TCP_ESTABLISHED; | |
866 | sk->sk_state_change(sk); | |
867 | } | |
868 | ||
869 | if ((cb->nsp_flags & 0x1c) == 0) | |
870 | other = 0; | |
871 | if (cb->nsp_flags == 0x04) | |
872 | other = 0; | |
873 | ||
874 | /* | |
875 | * Read out ack data here, this applies equally | |
876 | * to data, other data, link serivce and both | |
877 | * ack data and ack otherdata. | |
878 | */ | |
879 | dn_process_ack(sk, skb, other); | |
880 | ||
881 | /* | |
882 | * If we've some sort of data here then call a | |
883 | * suitable routine for dealing with it, otherwise | |
884 | * the packet is an ack and can be discarded. | |
885 | */ | |
886 | if ((cb->nsp_flags & 0x0c) == 0) { | |
887 | ||
888 | if (scp->state != DN_RUN) | |
889 | goto free_out; | |
890 | ||
891 | switch(cb->nsp_flags) { | |
892 | case 0x10: /* LS */ | |
893 | dn_nsp_linkservice(sk, skb); | |
894 | break; | |
895 | case 0x30: /* OD */ | |
896 | dn_nsp_otherdata(sk, skb); | |
897 | break; | |
898 | default: | |
899 | dn_nsp_data(sk, skb); | |
900 | } | |
901 | ||
902 | } else { /* Ack, chuck it out here */ | |
903 | free_out: | |
904 | kfree_skb(skb); | |
905 | } | |
906 | } | |
907 | ||
908 | return NET_RX_SUCCESS; | |
909 | } | |
910 |