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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); | |
c4ea94ab | 86 | printk(KERN_INFO "DECnet: Martian packet (%s) dev=%s src=0x%04hx dst=0x%04hx srcport=0x%04hx dstport=0x%04hx\n", msg, devname, dn_ntohs(cb->src), dn_ntohs(cb->dst), dn_ntohs(cb->src_port), dn_ntohs(cb->dst_port)); |
1da177e4 LT |
87 | } |
88 | } | |
89 | ||
90 | /* | |
91 | * For this function we've flipped the cross-subchannel bit | |
92 | * if the message is an otherdata or linkservice message. Thus | |
93 | * we can use it to work out what to update. | |
94 | */ | |
95 | static void dn_ack(struct sock *sk, struct sk_buff *skb, unsigned short ack) | |
96 | { | |
97 | struct dn_scp *scp = DN_SK(sk); | |
98 | unsigned short type = ((ack >> 12) & 0x0003); | |
99 | int wakeup = 0; | |
100 | ||
101 | switch(type) { | |
102 | case 0: /* ACK - Data */ | |
103 | if (dn_after(ack, scp->ackrcv_dat)) { | |
104 | scp->ackrcv_dat = ack & 0x0fff; | |
105 | wakeup |= dn_nsp_check_xmit_queue(sk, skb, &scp->data_xmit_queue, ack); | |
106 | } | |
107 | break; | |
108 | case 1: /* NAK - Data */ | |
109 | break; | |
110 | case 2: /* ACK - OtherData */ | |
111 | if (dn_after(ack, scp->ackrcv_oth)) { | |
112 | scp->ackrcv_oth = ack & 0x0fff; | |
113 | wakeup |= dn_nsp_check_xmit_queue(sk, skb, &scp->other_xmit_queue, ack); | |
114 | } | |
115 | break; | |
116 | case 3: /* NAK - OtherData */ | |
117 | break; | |
118 | } | |
119 | ||
120 | if (wakeup && !sock_flag(sk, SOCK_DEAD)) | |
121 | sk->sk_state_change(sk); | |
122 | } | |
123 | ||
124 | /* | |
125 | * This function is a universal ack processor. | |
126 | */ | |
127 | static int dn_process_ack(struct sock *sk, struct sk_buff *skb, int oth) | |
128 | { | |
c4ea94ab | 129 | __le16 *ptr = (__le16 *)skb->data; |
1da177e4 LT |
130 | int len = 0; |
131 | unsigned short ack; | |
132 | ||
133 | if (skb->len < 2) | |
134 | return len; | |
135 | ||
136 | if ((ack = dn_ntohs(*ptr)) & 0x8000) { | |
137 | skb_pull(skb, 2); | |
138 | ptr++; | |
139 | len += 2; | |
140 | if ((ack & 0x4000) == 0) { | |
429eb0fa | 141 | if (oth) |
1da177e4 LT |
142 | ack ^= 0x2000; |
143 | dn_ack(sk, skb, ack); | |
144 | } | |
145 | } | |
146 | ||
147 | if (skb->len < 2) | |
148 | return len; | |
149 | ||
150 | if ((ack = dn_ntohs(*ptr)) & 0x8000) { | |
151 | skb_pull(skb, 2); | |
152 | len += 2; | |
153 | if ((ack & 0x4000) == 0) { | |
429eb0fa | 154 | if (oth) |
1da177e4 LT |
155 | ack ^= 0x2000; |
156 | dn_ack(sk, skb, ack); | |
157 | } | |
158 | } | |
159 | ||
160 | return len; | |
161 | } | |
162 | ||
163 | ||
164 | /** | |
165 | * dn_check_idf - Check an image data field format is correct. | |
166 | * @pptr: Pointer to pointer to image data | |
167 | * @len: Pointer to length of image data | |
168 | * @max: The maximum allowed length of the data in the image data field | |
169 | * @follow_on: Check that this many bytes exist beyond the end of the image data | |
170 | * | |
171 | * Returns: 0 if ok, -1 on error | |
172 | */ | |
173 | static inline int dn_check_idf(unsigned char **pptr, int *len, unsigned char max, unsigned char follow_on) | |
174 | { | |
175 | unsigned char *ptr = *pptr; | |
176 | unsigned char flen = *ptr++; | |
177 | ||
178 | (*len)--; | |
179 | if (flen > max) | |
180 | return -1; | |
181 | if ((flen + follow_on) > *len) | |
182 | return -1; | |
183 | ||
184 | *len -= flen; | |
185 | *pptr = ptr + flen; | |
186 | return 0; | |
187 | } | |
188 | ||
189 | /* | |
190 | * Table of reason codes to pass back to node which sent us a badly | |
191 | * formed message, plus text messages for the log. A zero entry in | |
192 | * the reason field means "don't reply" otherwise a disc init is sent with | |
193 | * the specified reason code. | |
194 | */ | |
195 | static struct { | |
196 | unsigned short reason; | |
197 | const char *text; | |
198 | } ci_err_table[] = { | |
199 | { 0, "CI: Truncated message" }, | |
200 | { NSP_REASON_ID, "CI: Destination username error" }, | |
201 | { NSP_REASON_ID, "CI: Destination username type" }, | |
202 | { NSP_REASON_US, "CI: Source username error" }, | |
203 | { 0, "CI: Truncated at menuver" }, | |
204 | { 0, "CI: Truncated before access or user data" }, | |
205 | { NSP_REASON_IO, "CI: Access data format error" }, | |
206 | { NSP_REASON_IO, "CI: User data format error" } | |
207 | }; | |
208 | ||
209 | /* | |
210 | * This function uses a slightly different lookup method | |
211 | * to find its sockets, since it searches on object name/number | |
212 | * rather than port numbers. Various tests are done to ensure that | |
213 | * the incoming data is in the correct format before it is queued to | |
214 | * a socket. | |
215 | */ | |
216 | static struct sock *dn_find_listener(struct sk_buff *skb, unsigned short *reason) | |
217 | { | |
218 | struct dn_skb_cb *cb = DN_SKB_CB(skb); | |
219 | struct nsp_conn_init_msg *msg = (struct nsp_conn_init_msg *)skb->data; | |
220 | struct sockaddr_dn dstaddr; | |
221 | struct sockaddr_dn srcaddr; | |
222 | unsigned char type = 0; | |
223 | int dstlen; | |
224 | int srclen; | |
225 | unsigned char *ptr; | |
226 | int len; | |
227 | int err = 0; | |
228 | unsigned char menuver; | |
229 | ||
230 | memset(&dstaddr, 0, sizeof(struct sockaddr_dn)); | |
231 | memset(&srcaddr, 0, sizeof(struct sockaddr_dn)); | |
232 | ||
233 | /* | |
234 | * 1. Decode & remove message header | |
235 | */ | |
236 | cb->src_port = msg->srcaddr; | |
237 | cb->dst_port = msg->dstaddr; | |
238 | cb->services = msg->services; | |
239 | cb->info = msg->info; | |
240 | cb->segsize = dn_ntohs(msg->segsize); | |
241 | ||
242 | if (!pskb_may_pull(skb, sizeof(*msg))) | |
243 | goto err_out; | |
244 | ||
245 | skb_pull(skb, sizeof(*msg)); | |
246 | ||
247 | len = skb->len; | |
248 | ptr = skb->data; | |
249 | ||
250 | /* | |
251 | * 2. Check destination end username format | |
252 | */ | |
253 | dstlen = dn_username2sockaddr(ptr, len, &dstaddr, &type); | |
254 | err++; | |
255 | if (dstlen < 0) | |
256 | goto err_out; | |
257 | ||
258 | err++; | |
259 | if (type > 1) | |
260 | goto err_out; | |
261 | ||
262 | len -= dstlen; | |
263 | ptr += dstlen; | |
264 | ||
265 | /* | |
266 | * 3. Check source end username format | |
267 | */ | |
268 | srclen = dn_username2sockaddr(ptr, len, &srcaddr, &type); | |
269 | err++; | |
270 | if (srclen < 0) | |
271 | goto err_out; | |
272 | ||
273 | len -= srclen; | |
274 | ptr += srclen; | |
275 | err++; | |
276 | if (len < 1) | |
277 | goto err_out; | |
278 | ||
279 | menuver = *ptr; | |
280 | ptr++; | |
281 | len--; | |
282 | ||
283 | /* | |
284 | * 4. Check that optional data actually exists if menuver says it does | |
285 | */ | |
286 | err++; | |
287 | if ((menuver & (DN_MENUVER_ACC | DN_MENUVER_USR)) && (len < 1)) | |
288 | goto err_out; | |
289 | ||
290 | /* | |
291 | * 5. Check optional access data format | |
292 | */ | |
293 | err++; | |
294 | if (menuver & DN_MENUVER_ACC) { | |
295 | if (dn_check_idf(&ptr, &len, 39, 1)) | |
296 | goto err_out; | |
297 | if (dn_check_idf(&ptr, &len, 39, 1)) | |
298 | goto err_out; | |
299 | if (dn_check_idf(&ptr, &len, 39, (menuver & DN_MENUVER_USR) ? 1 : 0)) | |
300 | goto err_out; | |
301 | } | |
302 | ||
303 | /* | |
304 | * 6. Check optional user data format | |
305 | */ | |
306 | err++; | |
307 | if (menuver & DN_MENUVER_USR) { | |
308 | if (dn_check_idf(&ptr, &len, 16, 0)) | |
309 | goto err_out; | |
310 | } | |
311 | ||
312 | /* | |
313 | * 7. Look up socket based on destination end username | |
314 | */ | |
315 | return dn_sklist_find_listener(&dstaddr); | |
316 | err_out: | |
317 | dn_log_martian(skb, ci_err_table[err].text); | |
318 | *reason = ci_err_table[err].reason; | |
319 | return NULL; | |
320 | } | |
321 | ||
322 | ||
323 | static void dn_nsp_conn_init(struct sock *sk, struct sk_buff *skb) | |
324 | { | |
325 | if (sk_acceptq_is_full(sk)) { | |
326 | kfree_skb(skb); | |
327 | return; | |
328 | } | |
329 | ||
330 | sk->sk_ack_backlog++; | |
331 | skb_queue_tail(&sk->sk_receive_queue, skb); | |
332 | sk->sk_state_change(sk); | |
333 | } | |
334 | ||
335 | static void dn_nsp_conn_conf(struct sock *sk, struct sk_buff *skb) | |
336 | { | |
337 | struct dn_skb_cb *cb = DN_SKB_CB(skb); | |
338 | struct dn_scp *scp = DN_SK(sk); | |
339 | unsigned char *ptr; | |
340 | ||
341 | if (skb->len < 4) | |
342 | goto out; | |
343 | ||
344 | ptr = skb->data; | |
345 | cb->services = *ptr++; | |
346 | cb->info = *ptr++; | |
c4ea94ab | 347 | cb->segsize = dn_ntohs(*(__le16 *)ptr); |
1da177e4 LT |
348 | |
349 | if ((scp->state == DN_CI) || (scp->state == DN_CD)) { | |
350 | scp->persist = 0; | |
429eb0fa YH |
351 | scp->addrrem = cb->src_port; |
352 | sk->sk_state = TCP_ESTABLISHED; | |
353 | scp->state = DN_RUN; | |
1da177e4 LT |
354 | scp->services_rem = cb->services; |
355 | scp->info_rem = cb->info; | |
356 | scp->segsize_rem = cb->segsize; | |
357 | ||
358 | if ((scp->services_rem & NSP_FC_MASK) == NSP_FC_NONE) | |
359 | scp->max_window = decnet_no_fc_max_cwnd; | |
360 | ||
361 | if (skb->len > 0) { | |
375d9d71 | 362 | u16 dlen = *skb->data; |
1da177e4 | 363 | if ((dlen <= 16) && (dlen <= skb->len)) { |
375d9d71 | 364 | scp->conndata_in.opt_optl = dn_htons(dlen); |
1da177e4 LT |
365 | memcpy(scp->conndata_in.opt_data, skb->data + 1, dlen); |
366 | } | |
367 | } | |
429eb0fa YH |
368 | dn_nsp_send_link(sk, DN_NOCHANGE, 0); |
369 | if (!sock_flag(sk, SOCK_DEAD)) | |
370 | sk->sk_state_change(sk); | |
371 | } | |
1da177e4 LT |
372 | |
373 | out: | |
429eb0fa | 374 | kfree_skb(skb); |
1da177e4 LT |
375 | } |
376 | ||
377 | static void dn_nsp_conn_ack(struct sock *sk, struct sk_buff *skb) | |
378 | { | |
379 | struct dn_scp *scp = DN_SK(sk); | |
380 | ||
381 | if (scp->state == DN_CI) { | |
382 | scp->state = DN_CD; | |
383 | scp->persist = 0; | |
384 | } | |
385 | ||
386 | kfree_skb(skb); | |
387 | } | |
388 | ||
389 | static void dn_nsp_disc_init(struct sock *sk, struct sk_buff *skb) | |
390 | { | |
391 | struct dn_scp *scp = DN_SK(sk); | |
392 | struct dn_skb_cb *cb = DN_SKB_CB(skb); | |
393 | unsigned short reason; | |
394 | ||
395 | if (skb->len < 2) | |
396 | goto out; | |
397 | ||
c4ea94ab | 398 | reason = dn_ntohs(*(__le16 *)skb->data); |
1da177e4 LT |
399 | skb_pull(skb, 2); |
400 | ||
c4ea94ab | 401 | scp->discdata_in.opt_status = dn_htons(reason); |
1da177e4 LT |
402 | scp->discdata_in.opt_optl = 0; |
403 | memset(scp->discdata_in.opt_data, 0, 16); | |
404 | ||
405 | if (skb->len > 0) { | |
375d9d71 | 406 | u16 dlen = *skb->data; |
1da177e4 | 407 | if ((dlen <= 16) && (dlen <= skb->len)) { |
375d9d71 | 408 | scp->discdata_in.opt_optl = dn_htons(dlen); |
1da177e4 LT |
409 | memcpy(scp->discdata_in.opt_data, skb->data + 1, dlen); |
410 | } | |
411 | } | |
412 | ||
413 | scp->addrrem = cb->src_port; | |
414 | sk->sk_state = TCP_CLOSE; | |
415 | ||
416 | switch(scp->state) { | |
417 | case DN_CI: | |
418 | case DN_CD: | |
419 | scp->state = DN_RJ; | |
420 | sk->sk_err = ECONNREFUSED; | |
421 | break; | |
422 | case DN_RUN: | |
423 | sk->sk_shutdown |= SHUTDOWN_MASK; | |
424 | scp->state = DN_DN; | |
425 | break; | |
426 | case DN_DI: | |
427 | scp->state = DN_DIC; | |
428 | break; | |
429 | } | |
430 | ||
431 | if (!sock_flag(sk, SOCK_DEAD)) { | |
432 | if (sk->sk_socket->state != SS_UNCONNECTED) | |
433 | sk->sk_socket->state = SS_DISCONNECTING; | |
434 | sk->sk_state_change(sk); | |
435 | } | |
436 | ||
429eb0fa | 437 | /* |
1da177e4 LT |
438 | * It appears that its possible for remote machines to send disc |
439 | * init messages with no port identifier if we are in the CI and | |
440 | * possibly also the CD state. Obviously we shouldn't reply with | |
441 | * a message if we don't know what the end point is. | |
442 | */ | |
443 | if (scp->addrrem) { | |
444 | dn_nsp_send_disc(sk, NSP_DISCCONF, NSP_REASON_DC, GFP_ATOMIC); | |
445 | } | |
446 | scp->persist_fxn = dn_destroy_timer; | |
447 | scp->persist = dn_nsp_persist(sk); | |
448 | ||
449 | out: | |
450 | kfree_skb(skb); | |
451 | } | |
452 | ||
453 | /* | |
454 | * disc_conf messages are also called no_resources or no_link | |
455 | * messages depending upon the "reason" field. | |
456 | */ | |
457 | static void dn_nsp_disc_conf(struct sock *sk, struct sk_buff *skb) | |
458 | { | |
459 | struct dn_scp *scp = DN_SK(sk); | |
460 | unsigned short reason; | |
461 | ||
462 | if (skb->len != 2) | |
463 | goto out; | |
464 | ||
c4ea94ab | 465 | reason = dn_ntohs(*(__le16 *)skb->data); |
1da177e4 LT |
466 | |
467 | sk->sk_state = TCP_CLOSE; | |
468 | ||
469 | switch(scp->state) { | |
470 | case DN_CI: | |
471 | scp->state = DN_NR; | |
472 | break; | |
473 | case DN_DR: | |
474 | if (reason == NSP_REASON_DC) | |
475 | scp->state = DN_DRC; | |
476 | if (reason == NSP_REASON_NL) | |
477 | scp->state = DN_CN; | |
478 | break; | |
479 | case DN_DI: | |
480 | scp->state = DN_DIC; | |
481 | break; | |
482 | case DN_RUN: | |
483 | sk->sk_shutdown |= SHUTDOWN_MASK; | |
484 | case DN_CC: | |
485 | scp->state = DN_CN; | |
486 | } | |
487 | ||
488 | if (!sock_flag(sk, SOCK_DEAD)) { | |
489 | if (sk->sk_socket->state != SS_UNCONNECTED) | |
490 | sk->sk_socket->state = SS_DISCONNECTING; | |
491 | sk->sk_state_change(sk); | |
492 | } | |
493 | ||
494 | scp->persist_fxn = dn_destroy_timer; | |
495 | scp->persist = dn_nsp_persist(sk); | |
496 | ||
497 | out: | |
498 | kfree_skb(skb); | |
499 | } | |
500 | ||
501 | static void dn_nsp_linkservice(struct sock *sk, struct sk_buff *skb) | |
502 | { | |
503 | struct dn_scp *scp = DN_SK(sk); | |
504 | unsigned short segnum; | |
505 | unsigned char lsflags; | |
506 | signed char fcval; | |
507 | int wake_up = 0; | |
508 | char *ptr = skb->data; | |
509 | unsigned char fctype = scp->services_rem & NSP_FC_MASK; | |
510 | ||
511 | if (skb->len != 4) | |
512 | goto out; | |
513 | ||
c4ea94ab | 514 | segnum = dn_ntohs(*(__le16 *)ptr); |
1da177e4 LT |
515 | ptr += 2; |
516 | lsflags = *(unsigned char *)ptr++; | |
517 | fcval = *ptr; | |
518 | ||
519 | /* | |
520 | * Here we ignore erronous packets which should really | |
429eb0fa | 521 | * should cause a connection abort. It is not critical |
1da177e4 LT |
522 | * for now though. |
523 | */ | |
524 | if (lsflags & 0xf8) | |
525 | goto out; | |
526 | ||
527 | if (seq_next(scp->numoth_rcv, segnum)) { | |
528 | seq_add(&scp->numoth_rcv, 1); | |
529 | switch(lsflags & 0x04) { /* FCVAL INT */ | |
530 | case 0x00: /* Normal Request */ | |
531 | switch(lsflags & 0x03) { /* FCVAL MOD */ | |
429eb0fa | 532 | case 0x00: /* Request count */ |
1da177e4 LT |
533 | if (fcval < 0) { |
534 | unsigned char p_fcval = -fcval; | |
535 | if ((scp->flowrem_dat > p_fcval) && | |
536 | (fctype == NSP_FC_SCMC)) { | |
537 | scp->flowrem_dat -= p_fcval; | |
538 | } | |
539 | } else if (fcval > 0) { | |
540 | scp->flowrem_dat += fcval; | |
541 | wake_up = 1; | |
542 | } | |
429eb0fa | 543 | break; |
1da177e4 LT |
544 | case 0x01: /* Stop outgoing data */ |
545 | scp->flowrem_sw = DN_DONTSEND; | |
546 | break; | |
547 | case 0x02: /* Ok to start again */ | |
548 | scp->flowrem_sw = DN_SEND; | |
549 | dn_nsp_output(sk); | |
550 | wake_up = 1; | |
551 | } | |
552 | break; | |
553 | case 0x04: /* Interrupt Request */ | |
554 | if (fcval > 0) { | |
555 | scp->flowrem_oth += fcval; | |
556 | wake_up = 1; | |
557 | } | |
558 | break; | |
429eb0fa | 559 | } |
1da177e4 LT |
560 | if (wake_up && !sock_flag(sk, SOCK_DEAD)) |
561 | sk->sk_state_change(sk); | |
429eb0fa | 562 | } |
1da177e4 LT |
563 | |
564 | dn_nsp_send_oth_ack(sk); | |
565 | ||
566 | out: | |
567 | kfree_skb(skb); | |
568 | } | |
569 | ||
570 | /* | |
571 | * Copy of sock_queue_rcv_skb (from sock.h) without | |
572 | * bh_lock_sock() (its already held when this is called) which | |
573 | * also allows data and other data to be queued to a socket. | |
574 | */ | |
575 | static __inline__ int dn_queue_skb(struct sock *sk, struct sk_buff *skb, int sig, struct sk_buff_head *queue) | |
576 | { | |
577 | int err; | |
429eb0fa YH |
578 | |
579 | /* Cast skb->rcvbuf to unsigned... It's pointless, but reduces | |
580 | number of warnings when compiling with -W --ANK | |
581 | */ | |
582 | if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >= | |
1da177e4 | 583 | (unsigned)sk->sk_rcvbuf) { |
429eb0fa YH |
584 | err = -ENOMEM; |
585 | goto out; | |
586 | } | |
1da177e4 | 587 | |
fda9ef5d | 588 | err = sk_filter(sk, skb); |
1da177e4 LT |
589 | if (err) |
590 | goto out; | |
591 | ||
429eb0fa YH |
592 | skb_set_owner_r(skb, sk); |
593 | skb_queue_tail(queue, skb); | |
1da177e4 LT |
594 | |
595 | /* This code only runs from BH or BH protected context. | |
596 | * Therefore the plain read_lock is ok here. -DaveM | |
597 | */ | |
598 | read_lock(&sk->sk_callback_lock); | |
429eb0fa | 599 | if (!sock_flag(sk, SOCK_DEAD)) { |
1da177e4 LT |
600 | struct socket *sock = sk->sk_socket; |
601 | wake_up_interruptible(sk->sk_sleep); | |
602 | if (sock && sock->fasync_list && | |
603 | !test_bit(SOCK_ASYNC_WAITDATA, &sock->flags)) | |
429eb0fa | 604 | __kill_fasync(sock->fasync_list, sig, |
1da177e4 LT |
605 | (sig == SIGURG) ? POLL_PRI : POLL_IN); |
606 | } | |
607 | read_unlock(&sk->sk_callback_lock); | |
608 | out: | |
429eb0fa | 609 | return err; |
1da177e4 LT |
610 | } |
611 | ||
612 | static void dn_nsp_otherdata(struct sock *sk, struct sk_buff *skb) | |
613 | { | |
614 | struct dn_scp *scp = DN_SK(sk); | |
615 | unsigned short segnum; | |
616 | struct dn_skb_cb *cb = DN_SKB_CB(skb); | |
617 | int queued = 0; | |
618 | ||
619 | if (skb->len < 2) | |
620 | goto out; | |
621 | ||
c4ea94ab | 622 | cb->segnum = segnum = dn_ntohs(*(__le16 *)skb->data); |
1da177e4 LT |
623 | skb_pull(skb, 2); |
624 | ||
625 | if (seq_next(scp->numoth_rcv, segnum)) { | |
626 | ||
627 | if (dn_queue_skb(sk, skb, SIGURG, &scp->other_receive_queue) == 0) { | |
628 | seq_add(&scp->numoth_rcv, 1); | |
629 | scp->other_report = 0; | |
630 | queued = 1; | |
631 | } | |
632 | } | |
633 | ||
634 | dn_nsp_send_oth_ack(sk); | |
635 | out: | |
636 | if (!queued) | |
637 | kfree_skb(skb); | |
638 | } | |
639 | ||
640 | static void dn_nsp_data(struct sock *sk, struct sk_buff *skb) | |
641 | { | |
642 | int queued = 0; | |
643 | unsigned short segnum; | |
644 | struct dn_skb_cb *cb = DN_SKB_CB(skb); | |
645 | struct dn_scp *scp = DN_SK(sk); | |
646 | ||
647 | if (skb->len < 2) | |
648 | goto out; | |
649 | ||
c4ea94ab | 650 | cb->segnum = segnum = dn_ntohs(*(__le16 *)skb->data); |
1da177e4 LT |
651 | skb_pull(skb, 2); |
652 | ||
653 | if (seq_next(scp->numdat_rcv, segnum)) { | |
429eb0fa | 654 | if (dn_queue_skb(sk, skb, SIGIO, &sk->sk_receive_queue) == 0) { |
1da177e4 | 655 | seq_add(&scp->numdat_rcv, 1); |
429eb0fa YH |
656 | queued = 1; |
657 | } | |
1da177e4 LT |
658 | |
659 | if ((scp->flowloc_sw == DN_SEND) && dn_congested(sk)) { | |
660 | scp->flowloc_sw = DN_DONTSEND; | |
661 | dn_nsp_send_link(sk, DN_DONTSEND, 0); | |
662 | } | |
429eb0fa | 663 | } |
1da177e4 LT |
664 | |
665 | dn_nsp_send_data_ack(sk); | |
666 | out: | |
667 | if (!queued) | |
668 | kfree_skb(skb); | |
669 | } | |
670 | ||
671 | /* | |
672 | * If one of our conninit messages is returned, this function | |
673 | * deals with it. It puts the socket into the NO_COMMUNICATION | |
674 | * state. | |
675 | */ | |
676 | static void dn_returned_conn_init(struct sock *sk, struct sk_buff *skb) | |
677 | { | |
678 | struct dn_scp *scp = DN_SK(sk); | |
679 | ||
680 | if (scp->state == DN_CI) { | |
681 | scp->state = DN_NC; | |
682 | sk->sk_state = TCP_CLOSE; | |
683 | if (!sock_flag(sk, SOCK_DEAD)) | |
684 | sk->sk_state_change(sk); | |
685 | } | |
686 | ||
687 | kfree_skb(skb); | |
688 | } | |
689 | ||
690 | static int dn_nsp_no_socket(struct sk_buff *skb, unsigned short reason) | |
691 | { | |
692 | struct dn_skb_cb *cb = DN_SKB_CB(skb); | |
693 | int ret = NET_RX_DROP; | |
694 | ||
695 | /* Must not reply to returned packets */ | |
696 | if (cb->rt_flags & DN_RT_F_RTS) | |
697 | goto out; | |
698 | ||
699 | if ((reason != NSP_REASON_OK) && ((cb->nsp_flags & 0x0c) == 0x08)) { | |
700 | switch(cb->nsp_flags & 0x70) { | |
701 | case 0x10: | |
702 | case 0x60: /* (Retransmitted) Connect Init */ | |
703 | dn_nsp_return_disc(skb, NSP_DISCINIT, reason); | |
704 | ret = NET_RX_SUCCESS; | |
705 | break; | |
706 | case 0x20: /* Connect Confirm */ | |
707 | dn_nsp_return_disc(skb, NSP_DISCCONF, reason); | |
708 | ret = NET_RX_SUCCESS; | |
709 | break; | |
710 | } | |
711 | } | |
712 | ||
713 | out: | |
714 | kfree_skb(skb); | |
715 | return ret; | |
716 | } | |
717 | ||
718 | static int dn_nsp_rx_packet(struct sk_buff *skb) | |
719 | { | |
720 | struct dn_skb_cb *cb = DN_SKB_CB(skb); | |
721 | struct sock *sk = NULL; | |
722 | unsigned char *ptr = (unsigned char *)skb->data; | |
723 | unsigned short reason = NSP_REASON_NL; | |
724 | ||
725 | if (!pskb_may_pull(skb, 2)) | |
726 | goto free_out; | |
727 | ||
badff6d0 | 728 | skb_reset_transport_header(skb); |
1da177e4 LT |
729 | cb->nsp_flags = *ptr++; |
730 | ||
731 | if (decnet_debug_level & 2) | |
732 | printk(KERN_DEBUG "dn_nsp_rx: Message type 0x%02x\n", (int)cb->nsp_flags); | |
733 | ||
429eb0fa | 734 | if (cb->nsp_flags & 0x83) |
1da177e4 LT |
735 | goto free_out; |
736 | ||
737 | /* | |
738 | * Filter out conninits and useless packet types | |
739 | */ | |
740 | if ((cb->nsp_flags & 0x0c) == 0x08) { | |
741 | switch(cb->nsp_flags & 0x70) { | |
742 | case 0x00: /* NOP */ | |
743 | case 0x70: /* Reserved */ | |
744 | case 0x50: /* Reserved, Phase II node init */ | |
745 | goto free_out; | |
746 | case 0x10: | |
747 | case 0x60: | |
748 | if (unlikely(cb->rt_flags & DN_RT_F_RTS)) | |
749 | goto free_out; | |
750 | sk = dn_find_listener(skb, &reason); | |
751 | goto got_it; | |
752 | } | |
753 | } | |
754 | ||
755 | if (!pskb_may_pull(skb, 3)) | |
756 | goto free_out; | |
757 | ||
758 | /* | |
759 | * Grab the destination address. | |
760 | */ | |
c4ea94ab | 761 | cb->dst_port = *(__le16 *)ptr; |
1da177e4 LT |
762 | cb->src_port = 0; |
763 | ptr += 2; | |
764 | ||
765 | /* | |
766 | * If not a connack, grab the source address too. | |
767 | */ | |
768 | if (pskb_may_pull(skb, 5)) { | |
c4ea94ab | 769 | cb->src_port = *(__le16 *)ptr; |
1da177e4 LT |
770 | ptr += 2; |
771 | skb_pull(skb, 5); | |
772 | } | |
773 | ||
774 | /* | |
775 | * Returned packets... | |
776 | * Swap src & dst and look up in the normal way. | |
777 | */ | |
778 | if (unlikely(cb->rt_flags & DN_RT_F_RTS)) { | |
c4ea94ab | 779 | __le16 tmp = cb->dst_port; |
1da177e4 LT |
780 | cb->dst_port = cb->src_port; |
781 | cb->src_port = tmp; | |
782 | tmp = cb->dst; | |
783 | cb->dst = cb->src; | |
784 | cb->src = tmp; | |
785 | } | |
786 | ||
787 | /* | |
788 | * Find the socket to which this skb is destined. | |
789 | */ | |
790 | sk = dn_find_by_skb(skb); | |
791 | got_it: | |
792 | if (sk != NULL) { | |
793 | struct dn_scp *scp = DN_SK(sk); | |
1da177e4 LT |
794 | |
795 | /* Reset backoff */ | |
796 | scp->nsp_rxtshift = 0; | |
797 | ||
798 | /* | |
799 | * We linearize everything except data segments here. | |
800 | */ | |
801 | if (cb->nsp_flags & ~0x60) { | |
364c6bad | 802 | if (unlikely(skb_linearize(skb))) |
1da177e4 LT |
803 | goto free_out; |
804 | } | |
805 | ||
58a5a7b9 | 806 | return sk_receive_skb(sk, skb, 0); |
1da177e4 LT |
807 | } |
808 | ||
809 | return dn_nsp_no_socket(skb, reason); | |
810 | ||
811 | free_out: | |
812 | kfree_skb(skb); | |
813 | return NET_RX_DROP; | |
814 | } | |
815 | ||
816 | int dn_nsp_rx(struct sk_buff *skb) | |
817 | { | |
818 | return NF_HOOK(PF_DECnet, NF_DN_LOCAL_IN, skb, skb->dev, NULL, dn_nsp_rx_packet); | |
819 | } | |
820 | ||
821 | /* | |
822 | * This is the main receive routine for sockets. It is called | |
823 | * from the above when the socket is not busy, and also from | |
824 | * sock_release() when there is a backlog queued up. | |
825 | */ | |
826 | int dn_nsp_backlog_rcv(struct sock *sk, struct sk_buff *skb) | |
827 | { | |
828 | struct dn_scp *scp = DN_SK(sk); | |
829 | struct dn_skb_cb *cb = DN_SKB_CB(skb); | |
830 | ||
831 | if (cb->rt_flags & DN_RT_F_RTS) { | |
832 | if (cb->nsp_flags == 0x18 || cb->nsp_flags == 0x68) | |
833 | dn_returned_conn_init(sk, skb); | |
834 | else | |
835 | kfree_skb(skb); | |
836 | return NET_RX_SUCCESS; | |
837 | } | |
838 | ||
839 | /* | |
840 | * Control packet. | |
841 | */ | |
842 | if ((cb->nsp_flags & 0x0c) == 0x08) { | |
843 | switch(cb->nsp_flags & 0x70) { | |
844 | case 0x10: | |
845 | case 0x60: | |
846 | dn_nsp_conn_init(sk, skb); | |
847 | break; | |
848 | case 0x20: | |
849 | dn_nsp_conn_conf(sk, skb); | |
850 | break; | |
851 | case 0x30: | |
852 | dn_nsp_disc_init(sk, skb); | |
853 | break; | |
429eb0fa | 854 | case 0x40: |
1da177e4 LT |
855 | dn_nsp_disc_conf(sk, skb); |
856 | break; | |
857 | } | |
858 | ||
859 | } else if (cb->nsp_flags == 0x24) { | |
860 | /* | |
861 | * Special for connacks, 'cos they don't have | |
862 | * ack data or ack otherdata info. | |
863 | */ | |
864 | dn_nsp_conn_ack(sk, skb); | |
865 | } else { | |
866 | int other = 1; | |
867 | ||
868 | /* both data and ack frames can kick a CC socket into RUN */ | |
869 | if ((scp->state == DN_CC) && !sock_flag(sk, SOCK_DEAD)) { | |
870 | scp->state = DN_RUN; | |
871 | sk->sk_state = TCP_ESTABLISHED; | |
872 | sk->sk_state_change(sk); | |
873 | } | |
874 | ||
875 | if ((cb->nsp_flags & 0x1c) == 0) | |
876 | other = 0; | |
877 | if (cb->nsp_flags == 0x04) | |
878 | other = 0; | |
879 | ||
880 | /* | |
881 | * Read out ack data here, this applies equally | |
882 | * to data, other data, link serivce and both | |
883 | * ack data and ack otherdata. | |
884 | */ | |
885 | dn_process_ack(sk, skb, other); | |
886 | ||
887 | /* | |
888 | * If we've some sort of data here then call a | |
889 | * suitable routine for dealing with it, otherwise | |
890 | * the packet is an ack and can be discarded. | |
891 | */ | |
892 | if ((cb->nsp_flags & 0x0c) == 0) { | |
893 | ||
894 | if (scp->state != DN_RUN) | |
895 | goto free_out; | |
896 | ||
897 | switch(cb->nsp_flags) { | |
898 | case 0x10: /* LS */ | |
899 | dn_nsp_linkservice(sk, skb); | |
900 | break; | |
901 | case 0x30: /* OD */ | |
902 | dn_nsp_otherdata(sk, skb); | |
903 | break; | |
904 | default: | |
905 | dn_nsp_data(sk, skb); | |
906 | } | |
907 | ||
908 | } else { /* Ack, chuck it out here */ | |
909 | free_out: | |
910 | kfree_skb(skb); | |
911 | } | |
912 | } | |
913 | ||
914 | return NET_RX_SUCCESS; | |
915 | } | |
916 |