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tcp: minor optimization around tcp_hdr() usage in receive path
[linux-2.6/btrfs-unstable.git] / net / llc / af_llc.c
blob1beeea9549fa6ec1f7b0e5f9af8ff3250a316f59
1 /*
2 * af_llc.c - LLC User Interface SAPs
3 * Description:
4 * Functions in this module are implementation of socket based llc
5 * communications for the Linux operating system. Support of llc class
6 * one and class two is provided via SOCK_DGRAM and SOCK_STREAM
7 * respectively.
8 *
9 * An llc2 connection is (mac + sap), only one llc2 sap connection
10 * is allowed per mac. Though one sap may have multiple mac + sap
11 * connections.
12 *
13 * Copyright (c) 2001 by Jay Schulist <jschlst@samba.org>
14 * 2002-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
15 *
16 * This program can be redistributed or modified under the terms of the
17 * GNU General Public License as published by the Free Software Foundation.
18 * This program is distributed without any warranty or implied warranty
19 * of merchantability or fitness for a particular purpose.
20 *
21 * See the GNU General Public License for more details.
22 */
23 #include <linux/compiler.h>
24 #include <linux/kernel.h>
25 #include <linux/module.h>
26 #include <linux/rtnetlink.h>
27 #include <linux/init.h>
28 #include <linux/slab.h>
29 #include <linux/sched/signal.h>
30
31 #include <net/llc.h>
32 #include <net/llc_sap.h>
33 #include <net/llc_pdu.h>
34 #include <net/llc_conn.h>
35 #include <net/tcp_states.h>
36
37 /* remember: uninitialized global data is zeroed because its in .bss */
38 static u16 llc_ui_sap_last_autoport = LLC_SAP_DYN_START;
39 static u16 llc_ui_sap_link_no_max[256];
40 static struct sockaddr_llc llc_ui_addrnull;
41 static const struct proto_ops llc_ui_ops;
42
43 static bool llc_ui_wait_for_conn(struct sock *sk, long timeout);
44 static int llc_ui_wait_for_disc(struct sock *sk, long timeout);
45 static int llc_ui_wait_for_busy_core(struct sock *sk, long timeout);
46
47 #if 0
48 #define dprintk(args...) printk(KERN_DEBUG args)
49 #else
50 #define dprintk(args...)
51 #endif
52
53 /* Maybe we'll add some more in the future. */
54 #define LLC_CMSG_PKTINFO 1
55
56
57 /**
58 * llc_ui_next_link_no - return the next unused link number for a sap
59 * @sap: Address of sap to get link number from.
60 *
61 * Return the next unused link number for a given sap.
62 */
63 static inline u16 llc_ui_next_link_no(int sap)
64 {
65 return llc_ui_sap_link_no_max[sap]++;
66 }
67
68 /**
69 * llc_proto_type - return eth protocol for ARP header type
70 * @arphrd: ARP header type.
71 *
72 * Given an ARP header type return the corresponding ethernet protocol.
73 */
74 static inline __be16 llc_proto_type(u16 arphrd)
75 {
76 return htons(ETH_P_802_2);
77 }
78
79 /**
80 * llc_ui_addr_null - determines if a address structure is null
81 * @addr: Address to test if null.
82 */
83 static inline u8 llc_ui_addr_null(struct sockaddr_llc *addr)
84 {
85 return !memcmp(addr, &llc_ui_addrnull, sizeof(*addr));
86 }
87
88 /**
89 * llc_ui_header_len - return length of llc header based on operation
90 * @sk: Socket which contains a valid llc socket type.
91 * @addr: Complete sockaddr_llc structure received from the user.
92 *
93 * Provide the length of the llc header depending on what kind of
94 * operation the user would like to perform and the type of socket.
95 * Returns the correct llc header length.
96 */
97 static inline u8 llc_ui_header_len(struct sock *sk, struct sockaddr_llc *addr)
98 {
99 u8 rc = LLC_PDU_LEN_U;
100
101 if (addr->sllc_test || addr->sllc_xid)
102 rc = LLC_PDU_LEN_U;
103 else if (sk->sk_type == SOCK_STREAM)
104 rc = LLC_PDU_LEN_I;
105 return rc;
106 }
107
108 /**
109 * llc_ui_send_data - send data via reliable llc2 connection
110 * @sk: Connection the socket is using.
111 * @skb: Data the user wishes to send.
112 * @noblock: can we block waiting for data?
113 *
114 * Send data via reliable llc2 connection.
115 * Returns 0 upon success, non-zero if action did not succeed.
116 */
117 static int llc_ui_send_data(struct sock* sk, struct sk_buff *skb, int noblock)
118 {
119 struct llc_sock* llc = llc_sk(sk);
120 int rc = 0;
121
122 if (unlikely(llc_data_accept_state(llc->state) ||
123 llc->remote_busy_flag ||
124 llc->p_flag)) {
125 long timeout = sock_sndtimeo(sk, noblock);
126
127 rc = llc_ui_wait_for_busy_core(sk, timeout);
128 }
129 if (unlikely(!rc))
130 rc = llc_build_and_send_pkt(sk, skb);
131 return rc;
132 }
133
134 static void llc_ui_sk_init(struct socket *sock, struct sock *sk)
135 {
136 sock_graft(sk, sock);
137 sk->sk_type = sock->type;
138 sock->ops = &llc_ui_ops;
139 }
140
141 static struct proto llc_proto = {
142 .name = "LLC",
143 .owner = THIS_MODULE,
144 .obj_size = sizeof(struct llc_sock),
145 .slab_flags = SLAB_TYPESAFE_BY_RCU,
146 };
147
148 /**
149 * llc_ui_create - alloc and init a new llc_ui socket
150 * @net: network namespace (must be default network)
151 * @sock: Socket to initialize and attach allocated sk to.
152 * @protocol: Unused.
153 * @kern: on behalf of kernel or userspace
154 *
155 * Allocate and initialize a new llc_ui socket, validate the user wants a
156 * socket type we have available.
157 * Returns 0 upon success, negative upon failure.
158 */
159 static int llc_ui_create(struct net *net, struct socket *sock, int protocol,
160 int kern)
161 {
162 struct sock *sk;
163 int rc = -ESOCKTNOSUPPORT;
164
165 if (!ns_capable(net->user_ns, CAP_NET_RAW))
166 return -EPERM;
167
168 if (!net_eq(net, &init_net))
169 return -EAFNOSUPPORT;
170
171 if (likely(sock->type == SOCK_DGRAM || sock->type == SOCK_STREAM)) {
172 rc = -ENOMEM;
173 sk = llc_sk_alloc(net, PF_LLC, GFP_KERNEL, &llc_proto, kern);
174 if (sk) {
175 rc = 0;
176 llc_ui_sk_init(sock, sk);
177 }
178 }
179 return rc;
180 }
181
182 /**
183 * llc_ui_release - shutdown socket
184 * @sock: Socket to release.
185 *
186 * Shutdown and deallocate an existing socket.
187 */
188 static int llc_ui_release(struct socket *sock)
189 {
190 struct sock *sk = sock->sk;
191 struct llc_sock *llc;
192
193 if (unlikely(sk == NULL))
194 goto out;
195 sock_hold(sk);
196 lock_sock(sk);
197 llc = llc_sk(sk);
198 dprintk("%s: closing local(%02X) remote(%02X)\n", __func__,
199 llc->laddr.lsap, llc->daddr.lsap);
200 if (!llc_send_disc(sk))
201 llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo);
202 if (!sock_flag(sk, SOCK_ZAPPED)) {
203 struct llc_sap *sap = llc->sap;
204
205 /* Hold this for release_sock(), so that llc_backlog_rcv()
206 * could still use it.
207 */
208 llc_sap_hold(sap);
209 llc_sap_remove_socket(llc->sap, sk);
210 release_sock(sk);
211 llc_sap_put(sap);
212 } else {
213 release_sock(sk);
214 }
215 if (llc->dev)
216 dev_put(llc->dev);
217 sock_put(sk);
218 llc_sk_free(sk);
219 out:
220 return 0;
221 }
222
223 /**
224 * llc_ui_autoport - provide dynamically allocate SAP number
225 *
226 * Provide the caller with a dynamically allocated SAP number according
227 * to the rules that are set in this function. Returns: 0, upon failure,
228 * SAP number otherwise.
229 */
230 static int llc_ui_autoport(void)
231 {
232 struct llc_sap *sap;
233 int i, tries = 0;
234
235 while (tries < LLC_SAP_DYN_TRIES) {
236 for (i = llc_ui_sap_last_autoport;
237 i < LLC_SAP_DYN_STOP; i += 2) {
238 sap = llc_sap_find(i);
239 if (!sap) {
240 llc_ui_sap_last_autoport = i + 2;
241 goto out;
242 }
243 llc_sap_put(sap);
244 }
245 llc_ui_sap_last_autoport = LLC_SAP_DYN_START;
246 tries++;
247 }
248 i = 0;
249 out:
250 return i;
251 }
252
253 /**
254 * llc_ui_autobind - automatically bind a socket to a sap
255 * @sock: socket to bind
256 * @addr: address to connect to
257 *
258 * Used by llc_ui_connect and llc_ui_sendmsg when the user hasn't
259 * specifically used llc_ui_bind to bind to an specific address/sap
260 *
261 * Returns: 0 upon success, negative otherwise.
262 */
263 static int llc_ui_autobind(struct socket *sock, struct sockaddr_llc *addr)
264 {
265 struct sock *sk = sock->sk;
266 struct llc_sock *llc = llc_sk(sk);
267 struct llc_sap *sap;
268 int rc = -EINVAL;
269
270 if (!sock_flag(sk, SOCK_ZAPPED))
271 goto out;
272 rc = -ENODEV;
273 if (sk->sk_bound_dev_if) {
274 llc->dev = dev_get_by_index(&init_net, sk->sk_bound_dev_if);
275 if (llc->dev && addr->sllc_arphrd != llc->dev->type) {
276 dev_put(llc->dev);
277 llc->dev = NULL;
278 }
279 } else
280 llc->dev = dev_getfirstbyhwtype(&init_net, addr->sllc_arphrd);
281 if (!llc->dev)
282 goto out;
283 rc = -EUSERS;
284 llc->laddr.lsap = llc_ui_autoport();
285 if (!llc->laddr.lsap)
286 goto out;
287 rc = -EBUSY; /* some other network layer is using the sap */
288 sap = llc_sap_open(llc->laddr.lsap, NULL);
289 if (!sap)
290 goto out;
291 memcpy(llc->laddr.mac, llc->dev->dev_addr, IFHWADDRLEN);
292 memcpy(&llc->addr, addr, sizeof(llc->addr));
293 /* assign new connection to its SAP */
294 llc_sap_add_socket(sap, sk);
295 sock_reset_flag(sk, SOCK_ZAPPED);
296 rc = 0;
297 out:
298 return rc;
299 }
300
301 /**
302 * llc_ui_bind - bind a socket to a specific address.
303 * @sock: Socket to bind an address to.
304 * @uaddr: Address the user wants the socket bound to.
305 * @addrlen: Length of the uaddr structure.
306 *
307 * Bind a socket to a specific address. For llc a user is able to bind to
308 * a specific sap only or mac + sap.
309 * If the user desires to bind to a specific mac + sap, it is possible to
310 * have multiple sap connections via multiple macs.
311 * Bind and autobind for that matter must enforce the correct sap usage
312 * otherwise all hell will break loose.
313 * Returns: 0 upon success, negative otherwise.
314 */
315 static int llc_ui_bind(struct socket *sock, struct sockaddr *uaddr, int addrlen)
316 {
317 struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr;
318 struct sock *sk = sock->sk;
319 struct llc_sock *llc = llc_sk(sk);
320 struct llc_sap *sap;
321 int rc = -EINVAL;
322
323 dprintk("%s: binding %02X\n", __func__, addr->sllc_sap);
324
325 lock_sock(sk);
326 if (unlikely(!sock_flag(sk, SOCK_ZAPPED) || addrlen != sizeof(*addr)))
327 goto out;
328 rc = -EAFNOSUPPORT;
329 if (unlikely(addr->sllc_family != AF_LLC))
330 goto out;
331 rc = -ENODEV;
332 rcu_read_lock();
333 if (sk->sk_bound_dev_if) {
334 llc->dev = dev_get_by_index_rcu(&init_net, sk->sk_bound_dev_if);
335 if (llc->dev) {
336 if (!addr->sllc_arphrd)
337 addr->sllc_arphrd = llc->dev->type;
338 if (is_zero_ether_addr(addr->sllc_mac))
339 memcpy(addr->sllc_mac, llc->dev->dev_addr,
340 IFHWADDRLEN);
341 if (addr->sllc_arphrd != llc->dev->type ||
342 !ether_addr_equal(addr->sllc_mac,
343 llc->dev->dev_addr)) {
344 rc = -EINVAL;
345 llc->dev = NULL;
346 }
347 }
348 } else
349 llc->dev = dev_getbyhwaddr_rcu(&init_net, addr->sllc_arphrd,
350 addr->sllc_mac);
351 if (llc->dev)
352 dev_hold(llc->dev);
353 rcu_read_unlock();
354 if (!llc->dev)
355 goto out;
356 if (!addr->sllc_sap) {
357 rc = -EUSERS;
358 addr->sllc_sap = llc_ui_autoport();
359 if (!addr->sllc_sap)
360 goto out;
361 }
362 sap = llc_sap_find(addr->sllc_sap);
363 if (!sap) {
364 sap = llc_sap_open(addr->sllc_sap, NULL);
365 rc = -EBUSY; /* some other network layer is using the sap */
366 if (!sap)
367 goto out;
368 } else {
369 struct llc_addr laddr, daddr;
370 struct sock *ask;
371
372 memset(&laddr, 0, sizeof(laddr));
373 memset(&daddr, 0, sizeof(daddr));
374 /*
375 * FIXME: check if the address is multicast,
376 * only SOCK_DGRAM can do this.
377 */
378 memcpy(laddr.mac, addr->sllc_mac, IFHWADDRLEN);
379 laddr.lsap = addr->sllc_sap;
380 rc = -EADDRINUSE; /* mac + sap clash. */
381 ask = llc_lookup_established(sap, &daddr, &laddr);
382 if (ask) {
383 sock_put(ask);
384 goto out_put;
385 }
386 }
387 llc->laddr.lsap = addr->sllc_sap;
388 memcpy(llc->laddr.mac, addr->sllc_mac, IFHWADDRLEN);
389 memcpy(&llc->addr, addr, sizeof(llc->addr));
390 /* assign new connection to its SAP */
391 llc_sap_add_socket(sap, sk);
392 sock_reset_flag(sk, SOCK_ZAPPED);
393 rc = 0;
394 out_put:
395 llc_sap_put(sap);
396 out:
397 release_sock(sk);
398 return rc;
399 }
400
401 /**
402 * llc_ui_shutdown - shutdown a connect llc2 socket.
403 * @sock: Socket to shutdown.
404 * @how: What part of the socket to shutdown.
405 *
406 * Shutdown a connected llc2 socket. Currently this function only supports
407 * shutting down both sends and receives (2), we could probably make this
408 * function such that a user can shutdown only half the connection but not
409 * right now.
410 * Returns: 0 upon success, negative otherwise.
411 */
412 static int llc_ui_shutdown(struct socket *sock, int how)
413 {
414 struct sock *sk = sock->sk;
415 int rc = -ENOTCONN;
416
417 lock_sock(sk);
418 if (unlikely(sk->sk_state != TCP_ESTABLISHED))
419 goto out;
420 rc = -EINVAL;
421 if (how != 2)
422 goto out;
423 rc = llc_send_disc(sk);
424 if (!rc)
425 rc = llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo);
426 /* Wake up anyone sleeping in poll */
427 sk->sk_state_change(sk);
428 out:
429 release_sock(sk);
430 return rc;
431 }
432
433 /**
434 * llc_ui_connect - Connect to a remote llc2 mac + sap.
435 * @sock: Socket which will be connected to the remote destination.
436 * @uaddr: Remote and possibly the local address of the new connection.
437 * @addrlen: Size of uaddr structure.
438 * @flags: Operational flags specified by the user.
439 *
440 * Connect to a remote llc2 mac + sap. The caller must specify the
441 * destination mac and address to connect to. If the user hasn't previously
442 * called bind(2) with a smac the address of the first interface of the
443 * specified arp type will be used.
444 * This function will autobind if user did not previously call bind.
445 * Returns: 0 upon success, negative otherwise.
446 */
447 static int llc_ui_connect(struct socket *sock, struct sockaddr *uaddr,
448 int addrlen, int flags)
449 {
450 struct sock *sk = sock->sk;
451 struct llc_sock *llc = llc_sk(sk);
452 struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr;
453 int rc = -EINVAL;
454
455 lock_sock(sk);
456 if (unlikely(addrlen != sizeof(*addr)))
457 goto out;
458 rc = -EAFNOSUPPORT;
459 if (unlikely(addr->sllc_family != AF_LLC))
460 goto out;
461 if (unlikely(sk->sk_type != SOCK_STREAM))
462 goto out;
463 rc = -EALREADY;
464 if (unlikely(sock->state == SS_CONNECTING))
465 goto out;
466 /* bind connection to sap if user hasn't done it. */
467 if (sock_flag(sk, SOCK_ZAPPED)) {
468 /* bind to sap with null dev, exclusive */
469 rc = llc_ui_autobind(sock, addr);
470 if (rc)
471 goto out;
472 }
473 llc->daddr.lsap = addr->sllc_sap;
474 memcpy(llc->daddr.mac, addr->sllc_mac, IFHWADDRLEN);
475 sock->state = SS_CONNECTING;
476 sk->sk_state = TCP_SYN_SENT;
477 llc->link = llc_ui_next_link_no(llc->sap->laddr.lsap);
478 rc = llc_establish_connection(sk, llc->dev->dev_addr,
479 addr->sllc_mac, addr->sllc_sap);
480 if (rc) {
481 dprintk("%s: llc_ui_send_conn failed :-(\n", __func__);
482 sock->state = SS_UNCONNECTED;
483 sk->sk_state = TCP_CLOSE;
484 goto out;
485 }
486
487 if (sk->sk_state == TCP_SYN_SENT) {
488 const long timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
489
490 if (!timeo || !llc_ui_wait_for_conn(sk, timeo))
491 goto out;
492
493 rc = sock_intr_errno(timeo);
494 if (signal_pending(current))
495 goto out;
496 }
497
498 if (sk->sk_state == TCP_CLOSE)
499 goto sock_error;
500
501 sock->state = SS_CONNECTED;
502 rc = 0;
503 out:
504 release_sock(sk);
505 return rc;
506 sock_error:
507 rc = sock_error(sk) ? : -ECONNABORTED;
508 sock->state = SS_UNCONNECTED;
509 goto out;
510 }
511
512 /**
513 * llc_ui_listen - allow a normal socket to accept incoming connections
514 * @sock: Socket to allow incoming connections on.
515 * @backlog: Number of connections to queue.
516 *
517 * Allow a normal socket to accept incoming connections.
518 * Returns 0 upon success, negative otherwise.
519 */
520 static int llc_ui_listen(struct socket *sock, int backlog)
521 {
522 struct sock *sk = sock->sk;
523 int rc = -EINVAL;
524
525 lock_sock(sk);
526 if (unlikely(sock->state != SS_UNCONNECTED))
527 goto out;
528 rc = -EOPNOTSUPP;
529 if (unlikely(sk->sk_type != SOCK_STREAM))
530 goto out;
531 rc = -EAGAIN;
532 if (sock_flag(sk, SOCK_ZAPPED))
533 goto out;
534 rc = 0;
535 if (!(unsigned int)backlog) /* BSDism */
536 backlog = 1;
537 sk->sk_max_ack_backlog = backlog;
538 if (sk->sk_state != TCP_LISTEN) {
539 sk->sk_ack_backlog = 0;
540 sk->sk_state = TCP_LISTEN;
541 }
542 sk->sk_socket->flags |= __SO_ACCEPTCON;
543 out:
544 release_sock(sk);
545 return rc;
546 }
547
548 static int llc_ui_wait_for_disc(struct sock *sk, long timeout)
549 {
550 DEFINE_WAIT_FUNC(wait, woken_wake_function);
551 int rc = 0;
552
553 add_wait_queue(sk_sleep(sk), &wait);
554 while (1) {
555 if (sk_wait_event(sk, &timeout, sk->sk_state == TCP_CLOSE, &wait))
556 break;
557 rc = -ERESTARTSYS;
558 if (signal_pending(current))
559 break;
560 rc = -EAGAIN;
561 if (!timeout)
562 break;
563 rc = 0;
564 }
565 remove_wait_queue(sk_sleep(sk), &wait);
566 return rc;
567 }
568
569 static bool llc_ui_wait_for_conn(struct sock *sk, long timeout)
570 {
571 DEFINE_WAIT_FUNC(wait, woken_wake_function);
572
573 add_wait_queue(sk_sleep(sk), &wait);
574 while (1) {
575 if (sk_wait_event(sk, &timeout, sk->sk_state != TCP_SYN_SENT, &wait))
576 break;
577 if (signal_pending(current) || !timeout)
578 break;
579 }
580 remove_wait_queue(sk_sleep(sk), &wait);
581 return timeout;
582 }
583
584 static int llc_ui_wait_for_busy_core(struct sock *sk, long timeout)
585 {
586 DEFINE_WAIT_FUNC(wait, woken_wake_function);
587 struct llc_sock *llc = llc_sk(sk);
588 int rc;
589
590 add_wait_queue(sk_sleep(sk), &wait);
591 while (1) {
592 rc = 0;
593 if (sk_wait_event(sk, &timeout,
594 (sk->sk_shutdown & RCV_SHUTDOWN) ||
595 (!llc_data_accept_state(llc->state) &&
596 !llc->remote_busy_flag &&
597 !llc->p_flag), &wait))
598 break;
599 rc = -ERESTARTSYS;
600 if (signal_pending(current))
601 break;
602 rc = -EAGAIN;
603 if (!timeout)
604 break;
605 }
606 remove_wait_queue(sk_sleep(sk), &wait);
607 return rc;
608 }
609
610 static int llc_wait_data(struct sock *sk, long timeo)
611 {
612 int rc;
613
614 while (1) {
615 /*
616 * POSIX 1003.1g mandates this order.
617 */
618 rc = sock_error(sk);
619 if (rc)
620 break;
621 rc = 0;
622 if (sk->sk_shutdown & RCV_SHUTDOWN)
623 break;
624 rc = -EAGAIN;
625 if (!timeo)
626 break;
627 rc = sock_intr_errno(timeo);
628 if (signal_pending(current))
629 break;
630 rc = 0;
631 if (sk_wait_data(sk, &timeo, NULL))
632 break;
633 }
634 return rc;
635 }
636
637 static void llc_cmsg_rcv(struct msghdr *msg, struct sk_buff *skb)
638 {
639 struct llc_sock *llc = llc_sk(skb->sk);
640
641 if (llc->cmsg_flags & LLC_CMSG_PKTINFO) {
642 struct llc_pktinfo info;
643
644 memset(&info, 0, sizeof(info));
645 info.lpi_ifindex = llc_sk(skb->sk)->dev->ifindex;
646 llc_pdu_decode_dsap(skb, &info.lpi_sap);
647 llc_pdu_decode_da(skb, info.lpi_mac);
648 put_cmsg(msg, SOL_LLC, LLC_OPT_PKTINFO, sizeof(info), &info);
649 }
650 }
651
652 /**
653 * llc_ui_accept - accept a new incoming connection.
654 * @sock: Socket which connections arrive on.
655 * @newsock: Socket to move incoming connection to.
656 * @flags: User specified operational flags.
657 * @kern: If the socket is kernel internal
658 *
659 * Accept a new incoming connection.
660 * Returns 0 upon success, negative otherwise.
661 */
662 static int llc_ui_accept(struct socket *sock, struct socket *newsock, int flags,
663 bool kern)
664 {
665 struct sock *sk = sock->sk, *newsk;
666 struct llc_sock *llc, *newllc;
667 struct sk_buff *skb;
668 int rc = -EOPNOTSUPP;
669
670 dprintk("%s: accepting on %02X\n", __func__,
671 llc_sk(sk)->laddr.lsap);
672 lock_sock(sk);
673 if (unlikely(sk->sk_type != SOCK_STREAM))
674 goto out;
675 rc = -EINVAL;
676 if (unlikely(sock->state != SS_UNCONNECTED ||
677 sk->sk_state != TCP_LISTEN))
678 goto out;
679 /* wait for a connection to arrive. */
680 if (skb_queue_empty(&sk->sk_receive_queue)) {
681 rc = llc_wait_data(sk, sk->sk_rcvtimeo);
682 if (rc)
683 goto out;
684 }
685 dprintk("%s: got a new connection on %02X\n", __func__,
686 llc_sk(sk)->laddr.lsap);
687 skb = skb_dequeue(&sk->sk_receive_queue);
688 rc = -EINVAL;
689 if (!skb->sk)
690 goto frees;
691 rc = 0;
692 newsk = skb->sk;
693 /* attach connection to a new socket. */
694 llc_ui_sk_init(newsock, newsk);
695 sock_reset_flag(newsk, SOCK_ZAPPED);
696 newsk->sk_state = TCP_ESTABLISHED;
697 newsock->state = SS_CONNECTED;
698 llc = llc_sk(sk);
699 newllc = llc_sk(newsk);
700 memcpy(&newllc->addr, &llc->addr, sizeof(newllc->addr));
701 newllc->link = llc_ui_next_link_no(newllc->laddr.lsap);
702
703 /* put original socket back into a clean listen state. */
704 sk->sk_state = TCP_LISTEN;
705 sk->sk_ack_backlog--;
706 dprintk("%s: ok success on %02X, client on %02X\n", __func__,
707 llc_sk(sk)->addr.sllc_sap, newllc->daddr.lsap);
708 frees:
709 kfree_skb(skb);
710 out:
711 release_sock(sk);
712 return rc;
713 }
714
715 /**
716 * llc_ui_recvmsg - copy received data to the socket user.
717 * @sock: Socket to copy data from.
718 * @msg: Various user space related information.
719 * @len: Size of user buffer.
720 * @flags: User specified flags.
721 *
722 * Copy received data to the socket user.
723 * Returns non-negative upon success, negative otherwise.
724 */
725 static int llc_ui_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
726 int flags)
727 {
728 DECLARE_SOCKADDR(struct sockaddr_llc *, uaddr, msg->msg_name);
729 const int nonblock = flags & MSG_DONTWAIT;
730 struct sk_buff *skb = NULL;
731 struct sock *sk = sock->sk;
732 struct llc_sock *llc = llc_sk(sk);
733 unsigned long cpu_flags;
734 size_t copied = 0;
735 u32 peek_seq = 0;
736 u32 *seq, skb_len;
737 unsigned long used;
738 int target; /* Read at least this many bytes */
739 long timeo;
740
741 lock_sock(sk);
742 copied = -ENOTCONN;
743 if (unlikely(sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_LISTEN))
744 goto out;
745
746 timeo = sock_rcvtimeo(sk, nonblock);
747
748 seq = &llc->copied_seq;
749 if (flags & MSG_PEEK) {
750 peek_seq = llc->copied_seq;
751 seq = &peek_seq;
752 }
753
754 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
755 copied = 0;
756
757 do {
758 u32 offset;
759
760 /*
761 * We need to check signals first, to get correct SIGURG
762 * handling. FIXME: Need to check this doesn't impact 1003.1g
763 * and move it down to the bottom of the loop
764 */
765 if (signal_pending(current)) {
766 if (copied)
767 break;
768 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN;
769 break;
770 }
771
772 /* Next get a buffer. */
773
774 skb = skb_peek(&sk->sk_receive_queue);
775 if (skb) {
776 offset = *seq;
777 goto found_ok_skb;
778 }
779 /* Well, if we have backlog, try to process it now yet. */
780
781 if (copied >= target && !sk->sk_backlog.tail)
782 break;
783
784 if (copied) {
785 if (sk->sk_err ||
786 sk->sk_state == TCP_CLOSE ||
787 (sk->sk_shutdown & RCV_SHUTDOWN) ||
788 !timeo ||
789 (flags & MSG_PEEK))
790 break;
791 } else {
792 if (sock_flag(sk, SOCK_DONE))
793 break;
794
795 if (sk->sk_err) {
796 copied = sock_error(sk);
797 break;
798 }
799 if (sk->sk_shutdown & RCV_SHUTDOWN)
800 break;
801
802 if (sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_CLOSE) {
803 if (!sock_flag(sk, SOCK_DONE)) {
804 /*
805 * This occurs when user tries to read
806 * from never connected socket.
807 */
808 copied = -ENOTCONN;
809 break;
810 }
811 break;
812 }
813 if (!timeo) {
814 copied = -EAGAIN;
815 break;
816 }
817 }
818
819 if (copied >= target) { /* Do not sleep, just process backlog. */
820 release_sock(sk);
821 lock_sock(sk);
822 } else
823 sk_wait_data(sk, &timeo, NULL);
824
825 if ((flags & MSG_PEEK) && peek_seq != llc->copied_seq) {
826 net_dbg_ratelimited("LLC(%s:%d): Application bug, race in MSG_PEEK\n",
827 current->comm,
828 task_pid_nr(current));
829 peek_seq = llc->copied_seq;
830 }
831 continue;
832 found_ok_skb:
833 skb_len = skb->len;
834 /* Ok so how much can we use? */
835 used = skb->len - offset;
836 if (len < used)
837 used = len;
838
839 if (!(flags & MSG_TRUNC)) {
840 int rc = skb_copy_datagram_msg(skb, offset, msg, used);
841 if (rc) {
842 /* Exception. Bailout! */
843 if (!copied)
844 copied = -EFAULT;
845 break;
846 }
847 }
848
849 *seq += used;
850 copied += used;
851 len -= used;
852
853 /* For non stream protcols we get one packet per recvmsg call */
854 if (sk->sk_type != SOCK_STREAM)
855 goto copy_uaddr;
856
857 if (!(flags & MSG_PEEK)) {
858 spin_lock_irqsave(&sk->sk_receive_queue.lock, cpu_flags);
859 sk_eat_skb(sk, skb);
860 spin_unlock_irqrestore(&sk->sk_receive_queue.lock, cpu_flags);
861 *seq = 0;
862 }
863
864 /* Partial read */
865 if (used + offset < skb_len)
866 continue;
867 } while (len > 0);
868
869 out:
870 release_sock(sk);
871 return copied;
872 copy_uaddr:
873 if (uaddr != NULL && skb != NULL) {
874 memcpy(uaddr, llc_ui_skb_cb(skb), sizeof(*uaddr));
875 msg->msg_namelen = sizeof(*uaddr);
876 }
877 if (llc_sk(sk)->cmsg_flags)
878 llc_cmsg_rcv(msg, skb);
879
880 if (!(flags & MSG_PEEK)) {
881 spin_lock_irqsave(&sk->sk_receive_queue.lock, cpu_flags);
882 sk_eat_skb(sk, skb);
883 spin_unlock_irqrestore(&sk->sk_receive_queue.lock, cpu_flags);
884 *seq = 0;
885 }
886
887 goto out;
888 }
889
890 /**
891 * llc_ui_sendmsg - Transmit data provided by the socket user.
892 * @sock: Socket to transmit data from.
893 * @msg: Various user related information.
894 * @len: Length of data to transmit.
895 *
896 * Transmit data provided by the socket user.
897 * Returns non-negative upon success, negative otherwise.
898 */
899 static int llc_ui_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
900 {
901 struct sock *sk = sock->sk;
902 struct llc_sock *llc = llc_sk(sk);
903 DECLARE_SOCKADDR(struct sockaddr_llc *, addr, msg->msg_name);
904 int flags = msg->msg_flags;
905 int noblock = flags & MSG_DONTWAIT;
906 struct sk_buff *skb;
907 size_t size = 0;
908 int rc = -EINVAL, copied = 0, hdrlen;
909
910 dprintk("%s: sending from %02X to %02X\n", __func__,
911 llc->laddr.lsap, llc->daddr.lsap);
912 lock_sock(sk);
913 if (addr) {
914 if (msg->msg_namelen < sizeof(*addr))
915 goto release;
916 } else {
917 if (llc_ui_addr_null(&llc->addr))
918 goto release;
919 addr = &llc->addr;
920 }
921 /* must bind connection to sap if user hasn't done it. */
922 if (sock_flag(sk, SOCK_ZAPPED)) {
923 /* bind to sap with null dev, exclusive. */
924 rc = llc_ui_autobind(sock, addr);
925 if (rc)
926 goto release;
927 }
928 hdrlen = llc->dev->hard_header_len + llc_ui_header_len(sk, addr);
929 size = hdrlen + len;
930 if (size > llc->dev->mtu)
931 size = llc->dev->mtu;
932 copied = size - hdrlen;
933 rc = -EINVAL;
934 if (copied < 0)
935 goto release;
936 release_sock(sk);
937 skb = sock_alloc_send_skb(sk, size, noblock, &rc);
938 lock_sock(sk);
939 if (!skb)
940 goto release;
941 skb->dev = llc->dev;
942 skb->protocol = llc_proto_type(addr->sllc_arphrd);
943 skb_reserve(skb, hdrlen);
944 rc = memcpy_from_msg(skb_put(skb, copied), msg, copied);
945 if (rc)
946 goto out;
947 if (sk->sk_type == SOCK_DGRAM || addr->sllc_ua) {
948 llc_build_and_send_ui_pkt(llc->sap, skb, addr->sllc_mac,
949 addr->sllc_sap);
950 goto out;
951 }
952 if (addr->sllc_test) {
953 llc_build_and_send_test_pkt(llc->sap, skb, addr->sllc_mac,
954 addr->sllc_sap);
955 goto out;
956 }
957 if (addr->sllc_xid) {
958 llc_build_and_send_xid_pkt(llc->sap, skb, addr->sllc_mac,
959 addr->sllc_sap);
960 goto out;
961 }
962 rc = -ENOPROTOOPT;
963 if (!(sk->sk_type == SOCK_STREAM && !addr->sllc_ua))
964 goto out;
965 rc = llc_ui_send_data(sk, skb, noblock);
966 out:
967 if (rc) {
968 kfree_skb(skb);
969 release:
970 dprintk("%s: failed sending from %02X to %02X: %d\n",
971 __func__, llc->laddr.lsap, llc->daddr.lsap, rc);
972 }
973 release_sock(sk);
974 return rc ? : copied;
975 }
976
977 /**
978 * llc_ui_getname - return the address info of a socket
979 * @sock: Socket to get address of.
980 * @uaddr: Address structure to return information.
981 * @uaddrlen: Length of address structure.
982 * @peer: Does user want local or remote address information.
983 *
984 * Return the address information of a socket.
985 */
986 static int llc_ui_getname(struct socket *sock, struct sockaddr *uaddr,
987 int peer)
988 {
989 struct sockaddr_llc sllc;
990 struct sock *sk = sock->sk;
991 struct llc_sock *llc = llc_sk(sk);
992 int rc = -EBADF;
993
994 memset(&sllc, 0, sizeof(sllc));
995 lock_sock(sk);
996 if (sock_flag(sk, SOCK_ZAPPED))
997 goto out;
998 if (peer) {
999 rc = -ENOTCONN;
1000 if (sk->sk_state != TCP_ESTABLISHED)
1001 goto out;
1002 if(llc->dev)
1003 sllc.sllc_arphrd = llc->dev->type;
1004 sllc.sllc_sap = llc->daddr.lsap;
1005 memcpy(&sllc.sllc_mac, &llc->daddr.mac, IFHWADDRLEN);
1006 } else {
1007 rc = -EINVAL;
1008 if (!llc->sap)
1009 goto out;
1010 sllc.sllc_sap = llc->sap->laddr.lsap;
1011
1012 if (llc->dev) {
1013 sllc.sllc_arphrd = llc->dev->type;
1014 memcpy(&sllc.sllc_mac, llc->dev->dev_addr,
1015 IFHWADDRLEN);
1016 }
1017 }
1018 sllc.sllc_family = AF_LLC;
1019 memcpy(uaddr, &sllc, sizeof(sllc));
1020 rc = sizeof(sllc);
1021 out:
1022 release_sock(sk);
1023 return rc;
1024 }
1025
1026 /**
1027 * llc_ui_ioctl - io controls for PF_LLC
1028 * @sock: Socket to get/set info
1029 * @cmd: command
1030 * @arg: optional argument for cmd
1031 *
1032 * get/set info on llc sockets
1033 */
1034 static int llc_ui_ioctl(struct socket *sock, unsigned int cmd,
1035 unsigned long arg)
1036 {
1037 return -ENOIOCTLCMD;
1038 }
1039
1040 /**
1041 * llc_ui_setsockopt - set various connection specific parameters.
1042 * @sock: Socket to set options on.
1043 * @level: Socket level user is requesting operations on.
1044 * @optname: Operation name.
1045 * @optval: User provided operation data.
1046 * @optlen: Length of optval.
1047 *
1048 * Set various connection specific parameters.
1049 */
1050 static int llc_ui_setsockopt(struct socket *sock, int level, int optname,
1051 char __user *optval, unsigned int optlen)
1052 {
1053 struct sock *sk = sock->sk;
1054 struct llc_sock *llc = llc_sk(sk);
1055 unsigned int opt;
1056 int rc = -EINVAL;
1057
1058 lock_sock(sk);
1059 if (unlikely(level != SOL_LLC || optlen != sizeof(int)))
1060 goto out;
1061 rc = get_user(opt, (int __user *)optval);
1062 if (rc)
1063 goto out;
1064 rc = -EINVAL;
1065 switch (optname) {
1066 case LLC_OPT_RETRY:
1067 if (opt > LLC_OPT_MAX_RETRY)
1068 goto out;
1069 llc->n2 = opt;
1070 break;
1071 case LLC_OPT_SIZE:
1072 if (opt > LLC_OPT_MAX_SIZE)
1073 goto out;
1074 llc->n1 = opt;
1075 break;
1076 case LLC_OPT_ACK_TMR_EXP:
1077 if (opt > LLC_OPT_MAX_ACK_TMR_EXP)
1078 goto out;
1079 llc->ack_timer.expire = opt * HZ;
1080 break;
1081 case LLC_OPT_P_TMR_EXP:
1082 if (opt > LLC_OPT_MAX_P_TMR_EXP)
1083 goto out;
1084 llc->pf_cycle_timer.expire = opt * HZ;
1085 break;
1086 case LLC_OPT_REJ_TMR_EXP:
1087 if (opt > LLC_OPT_MAX_REJ_TMR_EXP)
1088 goto out;
1089 llc->rej_sent_timer.expire = opt * HZ;
1090 break;
1091 case LLC_OPT_BUSY_TMR_EXP:
1092 if (opt > LLC_OPT_MAX_BUSY_TMR_EXP)
1093 goto out;
1094 llc->busy_state_timer.expire = opt * HZ;
1095 break;
1096 case LLC_OPT_TX_WIN:
1097 if (opt > LLC_OPT_MAX_WIN)
1098 goto out;
1099 llc->k = opt;
1100 break;
1101 case LLC_OPT_RX_WIN:
1102 if (opt > LLC_OPT_MAX_WIN)
1103 goto out;
1104 llc->rw = opt;
1105 break;
1106 case LLC_OPT_PKTINFO:
1107 if (opt)
1108 llc->cmsg_flags |= LLC_CMSG_PKTINFO;
1109 else
1110 llc->cmsg_flags &= ~LLC_CMSG_PKTINFO;
1111 break;
1112 default:
1113 rc = -ENOPROTOOPT;
1114 goto out;
1115 }
1116 rc = 0;
1117 out:
1118 release_sock(sk);
1119 return rc;
1120 }
1121
1122 /**
1123 * llc_ui_getsockopt - get connection specific socket info
1124 * @sock: Socket to get information from.
1125 * @level: Socket level user is requesting operations on.
1126 * @optname: Operation name.
1127 * @optval: Variable to return operation data in.
1128 * @optlen: Length of optval.
1129 *
1130 * Get connection specific socket information.
1131 */
1132 static int llc_ui_getsockopt(struct socket *sock, int level, int optname,
1133 char __user *optval, int __user *optlen)
1134 {
1135 struct sock *sk = sock->sk;
1136 struct llc_sock *llc = llc_sk(sk);
1137 int val = 0, len = 0, rc = -EINVAL;
1138
1139 lock_sock(sk);
1140 if (unlikely(level != SOL_LLC))
1141 goto out;
1142 rc = get_user(len, optlen);
1143 if (rc)
1144 goto out;
1145 rc = -EINVAL;
1146 if (len != sizeof(int))
1147 goto out;
1148 switch (optname) {
1149 case LLC_OPT_RETRY:
1150 val = llc->n2; break;
1151 case LLC_OPT_SIZE:
1152 val = llc->n1; break;
1153 case LLC_OPT_ACK_TMR_EXP:
1154 val = llc->ack_timer.expire / HZ; break;
1155 case LLC_OPT_P_TMR_EXP:
1156 val = llc->pf_cycle_timer.expire / HZ; break;
1157 case LLC_OPT_REJ_TMR_EXP:
1158 val = llc->rej_sent_timer.expire / HZ; break;
1159 case LLC_OPT_BUSY_TMR_EXP:
1160 val = llc->busy_state_timer.expire / HZ; break;
1161 case LLC_OPT_TX_WIN:
1162 val = llc->k; break;
1163 case LLC_OPT_RX_WIN:
1164 val = llc->rw; break;
1165 case LLC_OPT_PKTINFO:
1166 val = (llc->cmsg_flags & LLC_CMSG_PKTINFO) != 0;
1167 break;
1168 default:
1169 rc = -ENOPROTOOPT;
1170 goto out;
1171 }
1172 rc = 0;
1173 if (put_user(len, optlen) || copy_to_user(optval, &val, len))
1174 rc = -EFAULT;
1175 out:
1176 release_sock(sk);
1177 return rc;
1178 }
1179
1180 static const struct net_proto_family llc_ui_family_ops = {
1181 .family = PF_LLC,
1182 .create = llc_ui_create,
1183 .owner = THIS_MODULE,
1184 };
1185
1186 static const struct proto_ops llc_ui_ops = {
1187 .family = PF_LLC,
1188 .owner = THIS_MODULE,
1189 .release = llc_ui_release,
1190 .bind = llc_ui_bind,
1191 .connect = llc_ui_connect,
1192 .socketpair = sock_no_socketpair,
1193 .accept = llc_ui_accept,
1194 .getname = llc_ui_getname,
1195 .poll = datagram_poll,
1196 .ioctl = llc_ui_ioctl,
1197 .listen = llc_ui_listen,
1198 .shutdown = llc_ui_shutdown,
1199 .setsockopt = llc_ui_setsockopt,
1200 .getsockopt = llc_ui_getsockopt,
1201 .sendmsg = llc_ui_sendmsg,
1202 .recvmsg = llc_ui_recvmsg,
1203 .mmap = sock_no_mmap,
1204 .sendpage = sock_no_sendpage,
1205 };
1206
1207 static const char llc_proc_err_msg[] __initconst =
1208 KERN_CRIT "LLC: Unable to register the proc_fs entries\n";
1209 static const char llc_sysctl_err_msg[] __initconst =
1210 KERN_CRIT "LLC: Unable to register the sysctl entries\n";
1211 static const char llc_sock_err_msg[] __initconst =
1212 KERN_CRIT "LLC: Unable to register the network family\n";
1213
1214 static int __init llc2_init(void)
1215 {
1216 int rc = proto_register(&llc_proto, 0);
1217
1218 if (rc != 0)
1219 goto out;
1220
1221 llc_build_offset_table();
1222 llc_station_init();
1223 llc_ui_sap_last_autoport = LLC_SAP_DYN_START;
1224 rc = llc_proc_init();
1225 if (rc != 0) {
1226 printk(llc_proc_err_msg);
1227 goto out_station;
1228 }
1229 rc = llc_sysctl_init();
1230 if (rc) {
1231 printk(llc_sysctl_err_msg);
1232 goto out_proc;
1233 }
1234 rc = sock_register(&llc_ui_family_ops);
1235 if (rc) {
1236 printk(llc_sock_err_msg);
1237 goto out_sysctl;
1238 }
1239 llc_add_pack(LLC_DEST_SAP, llc_sap_handler);
1240 llc_add_pack(LLC_DEST_CONN, llc_conn_handler);
1241 out:
1242 return rc;
1243 out_sysctl:
1244 llc_sysctl_exit();
1245 out_proc:
1246 llc_proc_exit();
1247 out_station:
1248 llc_station_exit();
1249 proto_unregister(&llc_proto);
1250 goto out;
1251 }
1252
1253 static void __exit llc2_exit(void)
1254 {
1255 llc_station_exit();
1256 llc_remove_pack(LLC_DEST_SAP);
1257 llc_remove_pack(LLC_DEST_CONN);
1258 sock_unregister(PF_LLC);
1259 llc_proc_exit();
1260 llc_sysctl_exit();
1261 proto_unregister(&llc_proto);
1262 }
1263
1264 module_init(llc2_init);
1265 module_exit(llc2_exit);
1266
1267 MODULE_LICENSE("GPL");
1268 MODULE_AUTHOR("Procom 1997, Jay Schullist 2001, Arnaldo C. Melo 2001-2003");
1269 MODULE_DESCRIPTION("IEEE 802.2 PF_LLC support");
1270 MODULE_ALIAS_NETPROTO(PF_LLC);
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