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