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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...) do {} while (0)
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)
102 rc = LLC_PDU_LEN_U;
103 else if (addr->sllc_xid)
104 /* We need to expand header to sizeof(struct llc_xid_info)
105 * since llc_pdu_init_as_xid_cmd() sets 4,5,6 bytes of LLC header
106 * as XID PDU. In llc_ui_sendmsg() we reserved header size and then
107 * filled all other space with user data. If we won't reserve this
108 * bytes, llc_pdu_init_as_xid_cmd() will overwrite user data
109 */
110 rc = LLC_PDU_LEN_U_XID;
111 else if (sk->sk_type == SOCK_STREAM)
112 rc = LLC_PDU_LEN_I;
113 return rc;
114}
115
116/**
117 * llc_ui_send_data - send data via reliable llc2 connection
118 * @sk: Connection the socket is using.
119 * @skb: Data the user wishes to send.
120 * @noblock: can we block waiting for data?
121 *
122 * Send data via reliable llc2 connection.
123 * Returns 0 upon success, non-zero if action did not succeed.
124 *
125 * This function always consumes a reference to the skb.
126 */
127static int llc_ui_send_data(struct sock* sk, struct sk_buff *skb, int noblock)
128{
129 struct llc_sock* llc = llc_sk(sk);
130
131 if (unlikely(llc_data_accept_state(llc->state) ||
132 llc->remote_busy_flag ||
133 llc->p_flag)) {
134 long timeout = sock_sndtimeo(sk, noblock);
135 int rc;
136
137 rc = llc_ui_wait_for_busy_core(sk, timeout);
138 if (rc) {
139 kfree_skb(skb);
140 return rc;
141 }
142 }
143 return llc_build_and_send_pkt(sk, skb);
144}
145
146static void llc_ui_sk_init(struct socket *sock, struct sock *sk)
147{
148 sock_graft(sk, sock);
149 sk->sk_type = sock->type;
150 sock->ops = &llc_ui_ops;
151}
152
153static struct proto llc_proto = {
154 .name = "LLC",
155 .owner = THIS_MODULE,
156 .obj_size = sizeof(struct llc_sock),
157 .slab_flags = SLAB_TYPESAFE_BY_RCU,
158};
159
160/**
161 * llc_ui_create - alloc and init a new llc_ui socket
162 * @net: network namespace (must be default network)
163 * @sock: Socket to initialize and attach allocated sk to.
164 * @protocol: Unused.
165 * @kern: on behalf of kernel or userspace
166 *
167 * Allocate and initialize a new llc_ui socket, validate the user wants a
168 * socket type we have available.
169 * Returns 0 upon success, negative upon failure.
170 */
171static int llc_ui_create(struct net *net, struct socket *sock, int protocol,
172 int kern)
173{
174 struct sock *sk;
175 int rc = -ESOCKTNOSUPPORT;
176
177 if (!ns_capable(net->user_ns, CAP_NET_RAW))
178 return -EPERM;
179
180 if (!net_eq(net, &init_net))
181 return -EAFNOSUPPORT;
182
183 if (likely(sock->type == SOCK_DGRAM || sock->type == SOCK_STREAM)) {
184 rc = -ENOMEM;
185 sk = llc_sk_alloc(net, PF_LLC, GFP_KERNEL, &llc_proto, kern);
186 if (sk) {
187 rc = 0;
188 llc_ui_sk_init(sock, sk);
189 }
190 }
191 return rc;
192}
193
194/**
195 * llc_ui_release - shutdown socket
196 * @sock: Socket to release.
197 *
198 * Shutdown and deallocate an existing socket.
199 */
200static int llc_ui_release(struct socket *sock)
201{
202 struct sock *sk = sock->sk;
203 struct llc_sock *llc;
204
205 if (unlikely(sk == NULL))
206 goto out;
207 sock_hold(sk);
208 lock_sock(sk);
209 llc = llc_sk(sk);
210 dprintk("%s: closing local(%02X) remote(%02X)\n", __func__,
211 llc->laddr.lsap, llc->daddr.lsap);
212 if (!llc_send_disc(sk))
213 llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo);
214 if (!sock_flag(sk, SOCK_ZAPPED)) {
215 struct llc_sap *sap = llc->sap;
216
217 /* Hold this for release_sock(), so that llc_backlog_rcv()
218 * could still use it.
219 */
220 llc_sap_hold(sap);
221 llc_sap_remove_socket(llc->sap, sk);
222 release_sock(sk);
223 llc_sap_put(sap);
224 } else {
225 release_sock(sk);
226 }
227 netdev_put(llc->dev, &llc->dev_tracker);
228 sock_put(sk);
229 sock_orphan(sk);
230 sock->sk = NULL;
231 llc_sk_free(sk);
232out:
233 return 0;
234}
235
236/**
237 * llc_ui_autoport - provide dynamically allocate SAP number
238 *
239 * Provide the caller with a dynamically allocated SAP number according
240 * to the rules that are set in this function. Returns: 0, upon failure,
241 * SAP number otherwise.
242 */
243static int llc_ui_autoport(void)
244{
245 struct llc_sap *sap;
246 int i, tries = 0;
247
248 while (tries < LLC_SAP_DYN_TRIES) {
249 for (i = llc_ui_sap_last_autoport;
250 i < LLC_SAP_DYN_STOP; i += 2) {
251 sap = llc_sap_find(i);
252 if (!sap) {
253 llc_ui_sap_last_autoport = i + 2;
254 goto out;
255 }
256 llc_sap_put(sap);
257 }
258 llc_ui_sap_last_autoport = LLC_SAP_DYN_START;
259 tries++;
260 }
261 i = 0;
262out:
263 return i;
264}
265
266/**
267 * llc_ui_autobind - automatically bind a socket to a sap
268 * @sock: socket to bind
269 * @addr: address to connect to
270 *
271 * Used by llc_ui_connect and llc_ui_sendmsg when the user hasn't
272 * specifically used llc_ui_bind to bind to an specific address/sap
273 *
274 * Returns: 0 upon success, negative otherwise.
275 */
276static int llc_ui_autobind(struct socket *sock, struct sockaddr_llc *addr)
277{
278 struct sock *sk = sock->sk;
279 struct llc_sock *llc = llc_sk(sk);
280 struct net_device *dev = NULL;
281 struct llc_sap *sap;
282 int rc = -EINVAL;
283
284 if (!sock_flag(sk, SOCK_ZAPPED))
285 goto out;
286 if (!addr->sllc_arphrd)
287 addr->sllc_arphrd = ARPHRD_ETHER;
288 if (addr->sllc_arphrd != ARPHRD_ETHER)
289 goto out;
290 rc = -ENODEV;
291 if (sk->sk_bound_dev_if) {
292 dev = dev_get_by_index(&init_net, sk->sk_bound_dev_if);
293 if (dev && addr->sllc_arphrd != dev->type) {
294 dev_put(dev);
295 dev = NULL;
296 }
297 } else
298 dev = dev_getfirstbyhwtype(&init_net, addr->sllc_arphrd);
299 if (!dev)
300 goto out;
301 rc = -EUSERS;
302 llc->laddr.lsap = llc_ui_autoport();
303 if (!llc->laddr.lsap)
304 goto out;
305 rc = -EBUSY; /* some other network layer is using the sap */
306 sap = llc_sap_open(llc->laddr.lsap, NULL);
307 if (!sap)
308 goto out;
309
310 /* Note: We do not expect errors from this point. */
311 llc->dev = dev;
312 netdev_tracker_alloc(llc->dev, &llc->dev_tracker, GFP_KERNEL);
313 dev = NULL;
314
315 memcpy(llc->laddr.mac, llc->dev->dev_addr, IFHWADDRLEN);
316 memcpy(&llc->addr, addr, sizeof(llc->addr));
317 /* assign new connection to its SAP */
318 llc_sap_add_socket(sap, sk);
319 sock_reset_flag(sk, SOCK_ZAPPED);
320 rc = 0;
321out:
322 dev_put(dev);
323 return rc;
324}
325
326/**
327 * llc_ui_bind - bind a socket to a specific address.
328 * @sock: Socket to bind an address to.
329 * @uaddr: Address the user wants the socket bound to.
330 * @addrlen: Length of the uaddr structure.
331 *
332 * Bind a socket to a specific address. For llc a user is able to bind to
333 * a specific sap only or mac + sap.
334 * If the user desires to bind to a specific mac + sap, it is possible to
335 * have multiple sap connections via multiple macs.
336 * Bind and autobind for that matter must enforce the correct sap usage
337 * otherwise all hell will break loose.
338 * Returns: 0 upon success, negative otherwise.
339 */
340static int llc_ui_bind(struct socket *sock, struct sockaddr *uaddr, int addrlen)
341{
342 struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr;
343 struct sock *sk = sock->sk;
344 struct llc_sock *llc = llc_sk(sk);
345 struct net_device *dev = NULL;
346 struct llc_sap *sap;
347 int rc = -EINVAL;
348
349 lock_sock(sk);
350 if (unlikely(!sock_flag(sk, SOCK_ZAPPED) || addrlen != sizeof(*addr)))
351 goto out;
352 rc = -EAFNOSUPPORT;
353 if (!addr->sllc_arphrd)
354 addr->sllc_arphrd = ARPHRD_ETHER;
355 if (unlikely(addr->sllc_family != AF_LLC || addr->sllc_arphrd != ARPHRD_ETHER))
356 goto out;
357 dprintk("%s: binding %02X\n", __func__, addr->sllc_sap);
358 rc = -ENODEV;
359 rcu_read_lock();
360 if (sk->sk_bound_dev_if) {
361 dev = dev_get_by_index_rcu(&init_net, sk->sk_bound_dev_if);
362 if (dev) {
363 if (is_zero_ether_addr(addr->sllc_mac))
364 memcpy(addr->sllc_mac, dev->dev_addr,
365 IFHWADDRLEN);
366 if (addr->sllc_arphrd != dev->type ||
367 !ether_addr_equal(addr->sllc_mac,
368 dev->dev_addr)) {
369 rc = -EINVAL;
370 dev = NULL;
371 }
372 }
373 } else {
374 dev = dev_getbyhwaddr_rcu(&init_net, addr->sllc_arphrd,
375 addr->sllc_mac);
376 }
377 dev_hold(dev);
378 rcu_read_unlock();
379 if (!dev)
380 goto out;
381
382 if (!addr->sllc_sap) {
383 rc = -EUSERS;
384 addr->sllc_sap = llc_ui_autoport();
385 if (!addr->sllc_sap)
386 goto out;
387 }
388 sap = llc_sap_find(addr->sllc_sap);
389 if (!sap) {
390 sap = llc_sap_open(addr->sllc_sap, NULL);
391 rc = -EBUSY; /* some other network layer is using the sap */
392 if (!sap)
393 goto out;
394 } else {
395 struct llc_addr laddr, daddr;
396 struct sock *ask;
397
398 memset(&laddr, 0, sizeof(laddr));
399 memset(&daddr, 0, sizeof(daddr));
400 /*
401 * FIXME: check if the address is multicast,
402 * only SOCK_DGRAM can do this.
403 */
404 memcpy(laddr.mac, addr->sllc_mac, IFHWADDRLEN);
405 laddr.lsap = addr->sllc_sap;
406 rc = -EADDRINUSE; /* mac + sap clash. */
407 ask = llc_lookup_established(sap, &daddr, &laddr, &init_net);
408 if (ask) {
409 sock_put(ask);
410 goto out_put;
411 }
412 }
413
414 /* Note: We do not expect errors from this point. */
415 llc->dev = dev;
416 netdev_tracker_alloc(llc->dev, &llc->dev_tracker, GFP_KERNEL);
417 dev = NULL;
418
419 llc->laddr.lsap = addr->sllc_sap;
420 memcpy(llc->laddr.mac, addr->sllc_mac, IFHWADDRLEN);
421 memcpy(&llc->addr, addr, sizeof(llc->addr));
422 /* assign new connection to its SAP */
423 llc_sap_add_socket(sap, sk);
424 sock_reset_flag(sk, SOCK_ZAPPED);
425 rc = 0;
426out_put:
427 llc_sap_put(sap);
428out:
429 dev_put(dev);
430 release_sock(sk);
431 return rc;
432}
433
434/**
435 * llc_ui_shutdown - shutdown a connect llc2 socket.
436 * @sock: Socket to shutdown.
437 * @how: What part of the socket to shutdown.
438 *
439 * Shutdown a connected llc2 socket. Currently this function only supports
440 * shutting down both sends and receives (2), we could probably make this
441 * function such that a user can shutdown only half the connection but not
442 * right now.
443 * Returns: 0 upon success, negative otherwise.
444 */
445static int llc_ui_shutdown(struct socket *sock, int how)
446{
447 struct sock *sk = sock->sk;
448 int rc = -ENOTCONN;
449
450 lock_sock(sk);
451 if (unlikely(sk->sk_state != TCP_ESTABLISHED))
452 goto out;
453 rc = -EINVAL;
454 if (how != 2)
455 goto out;
456 rc = llc_send_disc(sk);
457 if (!rc)
458 rc = llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo);
459 /* Wake up anyone sleeping in poll */
460 sk->sk_state_change(sk);
461out:
462 release_sock(sk);
463 return rc;
464}
465
466/**
467 * llc_ui_connect - Connect to a remote llc2 mac + sap.
468 * @sock: Socket which will be connected to the remote destination.
469 * @uaddr: Remote and possibly the local address of the new connection.
470 * @addrlen: Size of uaddr structure.
471 * @flags: Operational flags specified by the user.
472 *
473 * Connect to a remote llc2 mac + sap. The caller must specify the
474 * destination mac and address to connect to. If the user hasn't previously
475 * called bind(2) with a smac the address of the first interface of the
476 * specified arp type will be used.
477 * This function will autobind if user did not previously call bind.
478 * Returns: 0 upon success, negative otherwise.
479 */
480static int llc_ui_connect(struct socket *sock, struct sockaddr *uaddr,
481 int addrlen, int flags)
482{
483 struct sock *sk = sock->sk;
484 struct llc_sock *llc = llc_sk(sk);
485 struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr;
486 int rc = -EINVAL;
487
488 lock_sock(sk);
489 if (unlikely(addrlen != sizeof(*addr)))
490 goto out;
491 rc = -EAFNOSUPPORT;
492 if (unlikely(addr->sllc_family != AF_LLC))
493 goto out;
494 if (unlikely(sk->sk_type != SOCK_STREAM))
495 goto out;
496 rc = -EALREADY;
497 if (unlikely(sock->state == SS_CONNECTING))
498 goto out;
499 /* bind connection to sap if user hasn't done it. */
500 if (sock_flag(sk, SOCK_ZAPPED)) {
501 /* bind to sap with null dev, exclusive */
502 rc = llc_ui_autobind(sock, addr);
503 if (rc)
504 goto out;
505 }
506 llc->daddr.lsap = addr->sllc_sap;
507 memcpy(llc->daddr.mac, addr->sllc_mac, IFHWADDRLEN);
508 sock->state = SS_CONNECTING;
509 sk->sk_state = TCP_SYN_SENT;
510 llc->link = llc_ui_next_link_no(llc->sap->laddr.lsap);
511 rc = llc_establish_connection(sk, llc->dev->dev_addr,
512 addr->sllc_mac, addr->sllc_sap);
513 if (rc) {
514 dprintk("%s: llc_ui_send_conn failed :-(\n", __func__);
515 sock->state = SS_UNCONNECTED;
516 sk->sk_state = TCP_CLOSE;
517 goto out;
518 }
519
520 if (sk->sk_state == TCP_SYN_SENT) {
521 const long timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
522
523 if (!timeo || !llc_ui_wait_for_conn(sk, timeo))
524 goto out;
525
526 rc = sock_intr_errno(timeo);
527 if (signal_pending(current))
528 goto out;
529 }
530
531 if (sk->sk_state == TCP_CLOSE)
532 goto sock_error;
533
534 sock->state = SS_CONNECTED;
535 rc = 0;
536out:
537 release_sock(sk);
538 return rc;
539sock_error:
540 rc = sock_error(sk) ? : -ECONNABORTED;
541 sock->state = SS_UNCONNECTED;
542 goto out;
543}
544
545/**
546 * llc_ui_listen - allow a normal socket to accept incoming connections
547 * @sock: Socket to allow incoming connections on.
548 * @backlog: Number of connections to queue.
549 *
550 * Allow a normal socket to accept incoming connections.
551 * Returns 0 upon success, negative otherwise.
552 */
553static int llc_ui_listen(struct socket *sock, int backlog)
554{
555 struct sock *sk = sock->sk;
556 int rc = -EINVAL;
557
558 lock_sock(sk);
559 if (unlikely(sock->state != SS_UNCONNECTED))
560 goto out;
561 rc = -EOPNOTSUPP;
562 if (unlikely(sk->sk_type != SOCK_STREAM))
563 goto out;
564 rc = -EAGAIN;
565 if (sock_flag(sk, SOCK_ZAPPED))
566 goto out;
567 rc = 0;
568 if (!(unsigned int)backlog) /* BSDism */
569 backlog = 1;
570 sk->sk_max_ack_backlog = backlog;
571 if (sk->sk_state != TCP_LISTEN) {
572 sk->sk_ack_backlog = 0;
573 sk->sk_state = TCP_LISTEN;
574 }
575 sk->sk_socket->flags |= __SO_ACCEPTCON;
576out:
577 release_sock(sk);
578 return rc;
579}
580
581static int llc_ui_wait_for_disc(struct sock *sk, long timeout)
582{
583 DEFINE_WAIT_FUNC(wait, woken_wake_function);
584 int rc = 0;
585
586 add_wait_queue(sk_sleep(sk), &wait);
587 while (1) {
588 if (sk_wait_event(sk, &timeout,
589 READ_ONCE(sk->sk_state) == TCP_CLOSE, &wait))
590 break;
591 rc = -ERESTARTSYS;
592 if (signal_pending(current))
593 break;
594 rc = -EAGAIN;
595 if (!timeout)
596 break;
597 rc = 0;
598 }
599 remove_wait_queue(sk_sleep(sk), &wait);
600 return rc;
601}
602
603static bool llc_ui_wait_for_conn(struct sock *sk, long timeout)
604{
605 DEFINE_WAIT_FUNC(wait, woken_wake_function);
606
607 add_wait_queue(sk_sleep(sk), &wait);
608 while (1) {
609 if (sk_wait_event(sk, &timeout,
610 READ_ONCE(sk->sk_state) != TCP_SYN_SENT, &wait))
611 break;
612 if (signal_pending(current) || !timeout)
613 break;
614 }
615 remove_wait_queue(sk_sleep(sk), &wait);
616 return timeout;
617}
618
619static int llc_ui_wait_for_busy_core(struct sock *sk, long timeout)
620{
621 DEFINE_WAIT_FUNC(wait, woken_wake_function);
622 struct llc_sock *llc = llc_sk(sk);
623 int rc;
624
625 add_wait_queue(sk_sleep(sk), &wait);
626 while (1) {
627 rc = 0;
628 if (sk_wait_event(sk, &timeout,
629 (READ_ONCE(sk->sk_shutdown) & RCV_SHUTDOWN) ||
630 (!llc_data_accept_state(llc->state) &&
631 !llc->remote_busy_flag &&
632 !llc->p_flag), &wait))
633 break;
634 rc = -ERESTARTSYS;
635 if (signal_pending(current))
636 break;
637 rc = -EAGAIN;
638 if (!timeout)
639 break;
640 }
641 remove_wait_queue(sk_sleep(sk), &wait);
642 return rc;
643}
644
645static int llc_wait_data(struct sock *sk, long timeo)
646{
647 int rc;
648
649 while (1) {
650 /*
651 * POSIX 1003.1g mandates this order.
652 */
653 rc = sock_error(sk);
654 if (rc)
655 break;
656 rc = 0;
657 if (sk->sk_shutdown & RCV_SHUTDOWN)
658 break;
659 rc = -EAGAIN;
660 if (!timeo)
661 break;
662 rc = sock_intr_errno(timeo);
663 if (signal_pending(current))
664 break;
665 rc = 0;
666 if (sk_wait_data(sk, &timeo, NULL))
667 break;
668 }
669 return rc;
670}
671
672static void llc_cmsg_rcv(struct msghdr *msg, struct sk_buff *skb)
673{
674 struct llc_sock *llc = llc_sk(skb->sk);
675
676 if (llc->cmsg_flags & LLC_CMSG_PKTINFO) {
677 struct llc_pktinfo info;
678
679 memset(&info, 0, sizeof(info));
680 info.lpi_ifindex = llc_sk(skb->sk)->dev->ifindex;
681 llc_pdu_decode_dsap(skb, &info.lpi_sap);
682 llc_pdu_decode_da(skb, info.lpi_mac);
683 put_cmsg(msg, SOL_LLC, LLC_OPT_PKTINFO, sizeof(info), &info);
684 }
685}
686
687/**
688 * llc_ui_accept - accept a new incoming connection.
689 * @sock: Socket which connections arrive on.
690 * @newsock: Socket to move incoming connection to.
691 * @flags: User specified operational flags.
692 * @kern: If the socket is kernel internal
693 *
694 * Accept a new incoming connection.
695 * Returns 0 upon success, negative otherwise.
696 */
697static int llc_ui_accept(struct socket *sock, struct socket *newsock, int flags,
698 bool kern)
699{
700 struct sock *sk = sock->sk, *newsk;
701 struct llc_sock *llc, *newllc;
702 struct sk_buff *skb;
703 int rc = -EOPNOTSUPP;
704
705 dprintk("%s: accepting on %02X\n", __func__,
706 llc_sk(sk)->laddr.lsap);
707 lock_sock(sk);
708 if (unlikely(sk->sk_type != SOCK_STREAM))
709 goto out;
710 rc = -EINVAL;
711 if (unlikely(sock->state != SS_UNCONNECTED ||
712 sk->sk_state != TCP_LISTEN))
713 goto out;
714 /* wait for a connection to arrive. */
715 if (skb_queue_empty(&sk->sk_receive_queue)) {
716 rc = llc_wait_data(sk, sk->sk_rcvtimeo);
717 if (rc)
718 goto out;
719 }
720 dprintk("%s: got a new connection on %02X\n", __func__,
721 llc_sk(sk)->laddr.lsap);
722 skb = skb_dequeue(&sk->sk_receive_queue);
723 rc = -EINVAL;
724 if (!skb->sk)
725 goto frees;
726 rc = 0;
727 newsk = skb->sk;
728 /* attach connection to a new socket. */
729 llc_ui_sk_init(newsock, newsk);
730 sock_reset_flag(newsk, SOCK_ZAPPED);
731 newsk->sk_state = TCP_ESTABLISHED;
732 newsock->state = SS_CONNECTED;
733 llc = llc_sk(sk);
734 newllc = llc_sk(newsk);
735 memcpy(&newllc->addr, &llc->addr, sizeof(newllc->addr));
736 newllc->link = llc_ui_next_link_no(newllc->laddr.lsap);
737
738 /* put original socket back into a clean listen state. */
739 sk->sk_state = TCP_LISTEN;
740 sk_acceptq_removed(sk);
741 dprintk("%s: ok success on %02X, client on %02X\n", __func__,
742 llc_sk(sk)->addr.sllc_sap, newllc->daddr.lsap);
743frees:
744 kfree_skb(skb);
745out:
746 release_sock(sk);
747 return rc;
748}
749
750/**
751 * llc_ui_recvmsg - copy received data to the socket user.
752 * @sock: Socket to copy data from.
753 * @msg: Various user space related information.
754 * @len: Size of user buffer.
755 * @flags: User specified flags.
756 *
757 * Copy received data to the socket user.
758 * Returns non-negative upon success, negative otherwise.
759 */
760static int llc_ui_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
761 int flags)
762{
763 DECLARE_SOCKADDR(struct sockaddr_llc *, uaddr, msg->msg_name);
764 const int nonblock = flags & MSG_DONTWAIT;
765 struct sk_buff *skb = NULL;
766 struct sock *sk = sock->sk;
767 struct llc_sock *llc = llc_sk(sk);
768 size_t copied = 0;
769 u32 peek_seq = 0;
770 u32 *seq, skb_len;
771 unsigned long used;
772 int target; /* Read at least this many bytes */
773 long timeo;
774
775 lock_sock(sk);
776 copied = -ENOTCONN;
777 if (unlikely(sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_LISTEN))
778 goto out;
779
780 timeo = sock_rcvtimeo(sk, nonblock);
781
782 seq = &llc->copied_seq;
783 if (flags & MSG_PEEK) {
784 peek_seq = llc->copied_seq;
785 seq = &peek_seq;
786 }
787
788 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
789 copied = 0;
790
791 do {
792 u32 offset;
793
794 /*
795 * We need to check signals first, to get correct SIGURG
796 * handling. FIXME: Need to check this doesn't impact 1003.1g
797 * and move it down to the bottom of the loop
798 */
799 if (signal_pending(current)) {
800 if (copied)
801 break;
802 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN;
803 break;
804 }
805
806 /* Next get a buffer. */
807
808 skb = skb_peek(&sk->sk_receive_queue);
809 if (skb) {
810 offset = *seq;
811 goto found_ok_skb;
812 }
813 /* Well, if we have backlog, try to process it now yet. */
814
815 if (copied >= target && !READ_ONCE(sk->sk_backlog.tail))
816 break;
817
818 if (copied) {
819 if (sk->sk_err ||
820 sk->sk_state == TCP_CLOSE ||
821 (sk->sk_shutdown & RCV_SHUTDOWN) ||
822 !timeo ||
823 (flags & MSG_PEEK))
824 break;
825 } else {
826 if (sock_flag(sk, SOCK_DONE))
827 break;
828
829 if (sk->sk_err) {
830 copied = sock_error(sk);
831 break;
832 }
833 if (sk->sk_shutdown & RCV_SHUTDOWN)
834 break;
835
836 if (sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_CLOSE) {
837 if (!sock_flag(sk, SOCK_DONE)) {
838 /*
839 * This occurs when user tries to read
840 * from never connected socket.
841 */
842 copied = -ENOTCONN;
843 break;
844 }
845 break;
846 }
847 if (!timeo) {
848 copied = -EAGAIN;
849 break;
850 }
851 }
852
853 if (copied >= target) { /* Do not sleep, just process backlog. */
854 release_sock(sk);
855 lock_sock(sk);
856 } else
857 sk_wait_data(sk, &timeo, NULL);
858
859 if ((flags & MSG_PEEK) && peek_seq != llc->copied_seq) {
860 net_dbg_ratelimited("LLC(%s:%d): Application bug, race in MSG_PEEK\n",
861 current->comm,
862 task_pid_nr(current));
863 peek_seq = llc->copied_seq;
864 }
865 continue;
866 found_ok_skb:
867 skb_len = skb->len;
868 /* Ok so how much can we use? */
869 used = skb->len - offset;
870 if (len < used)
871 used = len;
872
873 if (!(flags & MSG_TRUNC)) {
874 int rc = skb_copy_datagram_msg(skb, offset, msg, used);
875 if (rc) {
876 /* Exception. Bailout! */
877 if (!copied)
878 copied = -EFAULT;
879 break;
880 }
881 }
882
883 *seq += used;
884 copied += used;
885 len -= used;
886
887 /* For non stream protcols we get one packet per recvmsg call */
888 if (sk->sk_type != SOCK_STREAM)
889 goto copy_uaddr;
890
891 if (!(flags & MSG_PEEK)) {
892 skb_unlink(skb, &sk->sk_receive_queue);
893 kfree_skb(skb);
894 *seq = 0;
895 }
896
897 /* Partial read */
898 if (used + offset < skb_len)
899 continue;
900 } while (len > 0);
901
902out:
903 release_sock(sk);
904 return copied;
905copy_uaddr:
906 if (uaddr != NULL && skb != NULL) {
907 memcpy(uaddr, llc_ui_skb_cb(skb), sizeof(*uaddr));
908 msg->msg_namelen = sizeof(*uaddr);
909 }
910 if (llc_sk(sk)->cmsg_flags)
911 llc_cmsg_rcv(msg, skb);
912
913 if (!(flags & MSG_PEEK)) {
914 skb_unlink(skb, &sk->sk_receive_queue);
915 kfree_skb(skb);
916 *seq = 0;
917 }
918
919 goto out;
920}
921
922/**
923 * llc_ui_sendmsg - Transmit data provided by the socket user.
924 * @sock: Socket to transmit data from.
925 * @msg: Various user related information.
926 * @len: Length of data to transmit.
927 *
928 * Transmit data provided by the socket user.
929 * Returns non-negative upon success, negative otherwise.
930 */
931static int llc_ui_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
932{
933 DECLARE_SOCKADDR(struct sockaddr_llc *, addr, msg->msg_name);
934 struct sock *sk = sock->sk;
935 struct llc_sock *llc = llc_sk(sk);
936 int flags = msg->msg_flags;
937 int noblock = flags & MSG_DONTWAIT;
938 int rc = -EINVAL, copied = 0, hdrlen, hh_len;
939 struct sk_buff *skb = NULL;
940 struct net_device *dev;
941 size_t size = 0;
942
943 dprintk("%s: sending from %02X to %02X\n", __func__,
944 llc->laddr.lsap, llc->daddr.lsap);
945 lock_sock(sk);
946 if (addr) {
947 if (msg->msg_namelen < sizeof(*addr))
948 goto out;
949 } else {
950 if (llc_ui_addr_null(&llc->addr))
951 goto out;
952 addr = &llc->addr;
953 }
954 /* must bind connection to sap if user hasn't done it. */
955 if (sock_flag(sk, SOCK_ZAPPED)) {
956 /* bind to sap with null dev, exclusive. */
957 rc = llc_ui_autobind(sock, addr);
958 if (rc)
959 goto out;
960 }
961 dev = llc->dev;
962 hh_len = LL_RESERVED_SPACE(dev);
963 hdrlen = llc_ui_header_len(sk, addr);
964 size = hdrlen + len;
965 size = min_t(size_t, size, READ_ONCE(dev->mtu));
966 copied = size - hdrlen;
967 rc = -EINVAL;
968 if (copied < 0)
969 goto out;
970 release_sock(sk);
971 skb = sock_alloc_send_skb(sk, hh_len + size, noblock, &rc);
972 lock_sock(sk);
973 if (!skb)
974 goto out;
975 if (sock_flag(sk, SOCK_ZAPPED) ||
976 llc->dev != dev ||
977 hdrlen != llc_ui_header_len(sk, addr) ||
978 hh_len != LL_RESERVED_SPACE(dev) ||
979 size > READ_ONCE(dev->mtu))
980 goto out;
981 skb->dev = dev;
982 skb->protocol = llc_proto_type(addr->sllc_arphrd);
983 skb_reserve(skb, hh_len + hdrlen);
984 rc = memcpy_from_msg(skb_put(skb, copied), msg, copied);
985 if (rc)
986 goto out;
987 if (sk->sk_type == SOCK_DGRAM || addr->sllc_ua) {
988 llc_build_and_send_ui_pkt(llc->sap, skb, addr->sllc_mac,
989 addr->sllc_sap);
990 skb = NULL;
991 goto out;
992 }
993 if (addr->sllc_test) {
994 llc_build_and_send_test_pkt(llc->sap, skb, addr->sllc_mac,
995 addr->sllc_sap);
996 skb = NULL;
997 goto out;
998 }
999 if (addr->sllc_xid) {
1000 llc_build_and_send_xid_pkt(llc->sap, skb, addr->sllc_mac,
1001 addr->sllc_sap);
1002 skb = NULL;
1003 goto out;
1004 }
1005 rc = -ENOPROTOOPT;
1006 if (!(sk->sk_type == SOCK_STREAM && !addr->sllc_ua))
1007 goto out;
1008 rc = llc_ui_send_data(sk, skb, noblock);
1009 skb = NULL;
1010out:
1011 kfree_skb(skb);
1012 if (rc)
1013 dprintk("%s: failed sending from %02X to %02X: %d\n",
1014 __func__, llc->laddr.lsap, llc->daddr.lsap, rc);
1015 release_sock(sk);
1016 return rc ? : copied;
1017}
1018
1019/**
1020 * llc_ui_getname - return the address info of a socket
1021 * @sock: Socket to get address of.
1022 * @uaddr: Address structure to return information.
1023 * @peer: Does user want local or remote address information.
1024 *
1025 * Return the address information of a socket.
1026 */
1027static int llc_ui_getname(struct socket *sock, struct sockaddr *uaddr,
1028 int peer)
1029{
1030 struct sockaddr_llc sllc;
1031 struct sock *sk = sock->sk;
1032 struct llc_sock *llc = llc_sk(sk);
1033 int rc = -EBADF;
1034
1035 memset(&sllc, 0, sizeof(sllc));
1036 lock_sock(sk);
1037 if (sock_flag(sk, SOCK_ZAPPED))
1038 goto out;
1039 if (peer) {
1040 rc = -ENOTCONN;
1041 if (sk->sk_state != TCP_ESTABLISHED)
1042 goto out;
1043 if(llc->dev)
1044 sllc.sllc_arphrd = llc->dev->type;
1045 sllc.sllc_sap = llc->daddr.lsap;
1046 memcpy(&sllc.sllc_mac, &llc->daddr.mac, IFHWADDRLEN);
1047 } else {
1048 rc = -EINVAL;
1049 if (!llc->sap)
1050 goto out;
1051 sllc.sllc_sap = llc->sap->laddr.lsap;
1052
1053 if (llc->dev) {
1054 sllc.sllc_arphrd = llc->dev->type;
1055 memcpy(&sllc.sllc_mac, llc->dev->dev_addr,
1056 IFHWADDRLEN);
1057 }
1058 }
1059 sllc.sllc_family = AF_LLC;
1060 memcpy(uaddr, &sllc, sizeof(sllc));
1061 rc = sizeof(sllc);
1062out:
1063 release_sock(sk);
1064 return rc;
1065}
1066
1067/**
1068 * llc_ui_ioctl - io controls for PF_LLC
1069 * @sock: Socket to get/set info
1070 * @cmd: command
1071 * @arg: optional argument for cmd
1072 *
1073 * get/set info on llc sockets
1074 */
1075static int llc_ui_ioctl(struct socket *sock, unsigned int cmd,
1076 unsigned long arg)
1077{
1078 return -ENOIOCTLCMD;
1079}
1080
1081/**
1082 * llc_ui_setsockopt - set various connection specific parameters.
1083 * @sock: Socket to set options on.
1084 * @level: Socket level user is requesting operations on.
1085 * @optname: Operation name.
1086 * @optval: User provided operation data.
1087 * @optlen: Length of optval.
1088 *
1089 * Set various connection specific parameters.
1090 */
1091static int llc_ui_setsockopt(struct socket *sock, int level, int optname,
1092 sockptr_t optval, unsigned int optlen)
1093{
1094 struct sock *sk = sock->sk;
1095 struct llc_sock *llc = llc_sk(sk);
1096 unsigned int opt;
1097 int rc = -EINVAL;
1098
1099 lock_sock(sk);
1100 if (unlikely(level != SOL_LLC || optlen != sizeof(int)))
1101 goto out;
1102 rc = copy_from_sockptr(&opt, optval, sizeof(opt));
1103 if (rc)
1104 goto out;
1105 rc = -EINVAL;
1106 switch (optname) {
1107 case LLC_OPT_RETRY:
1108 if (opt > LLC_OPT_MAX_RETRY)
1109 goto out;
1110 llc->n2 = opt;
1111 break;
1112 case LLC_OPT_SIZE:
1113 if (opt > LLC_OPT_MAX_SIZE)
1114 goto out;
1115 llc->n1 = opt;
1116 break;
1117 case LLC_OPT_ACK_TMR_EXP:
1118 if (opt > LLC_OPT_MAX_ACK_TMR_EXP)
1119 goto out;
1120 llc->ack_timer.expire = opt * HZ;
1121 break;
1122 case LLC_OPT_P_TMR_EXP:
1123 if (opt > LLC_OPT_MAX_P_TMR_EXP)
1124 goto out;
1125 llc->pf_cycle_timer.expire = opt * HZ;
1126 break;
1127 case LLC_OPT_REJ_TMR_EXP:
1128 if (opt > LLC_OPT_MAX_REJ_TMR_EXP)
1129 goto out;
1130 llc->rej_sent_timer.expire = opt * HZ;
1131 break;
1132 case LLC_OPT_BUSY_TMR_EXP:
1133 if (opt > LLC_OPT_MAX_BUSY_TMR_EXP)
1134 goto out;
1135 llc->busy_state_timer.expire = opt * HZ;
1136 break;
1137 case LLC_OPT_TX_WIN:
1138 if (opt > LLC_OPT_MAX_WIN)
1139 goto out;
1140 llc->k = opt;
1141 break;
1142 case LLC_OPT_RX_WIN:
1143 if (opt > LLC_OPT_MAX_WIN)
1144 goto out;
1145 llc->rw = opt;
1146 break;
1147 case LLC_OPT_PKTINFO:
1148 if (opt)
1149 llc->cmsg_flags |= LLC_CMSG_PKTINFO;
1150 else
1151 llc->cmsg_flags &= ~LLC_CMSG_PKTINFO;
1152 break;
1153 default:
1154 rc = -ENOPROTOOPT;
1155 goto out;
1156 }
1157 rc = 0;
1158out:
1159 release_sock(sk);
1160 return rc;
1161}
1162
1163/**
1164 * llc_ui_getsockopt - get connection specific socket info
1165 * @sock: Socket to get information from.
1166 * @level: Socket level user is requesting operations on.
1167 * @optname: Operation name.
1168 * @optval: Variable to return operation data in.
1169 * @optlen: Length of optval.
1170 *
1171 * Get connection specific socket information.
1172 */
1173static int llc_ui_getsockopt(struct socket *sock, int level, int optname,
1174 char __user *optval, int __user *optlen)
1175{
1176 struct sock *sk = sock->sk;
1177 struct llc_sock *llc = llc_sk(sk);
1178 int val = 0, len = 0, rc = -EINVAL;
1179
1180 lock_sock(sk);
1181 if (unlikely(level != SOL_LLC))
1182 goto out;
1183 rc = get_user(len, optlen);
1184 if (rc)
1185 goto out;
1186 rc = -EINVAL;
1187 if (len != sizeof(int))
1188 goto out;
1189 switch (optname) {
1190 case LLC_OPT_RETRY:
1191 val = llc->n2; break;
1192 case LLC_OPT_SIZE:
1193 val = llc->n1; break;
1194 case LLC_OPT_ACK_TMR_EXP:
1195 val = llc->ack_timer.expire / HZ; break;
1196 case LLC_OPT_P_TMR_EXP:
1197 val = llc->pf_cycle_timer.expire / HZ; break;
1198 case LLC_OPT_REJ_TMR_EXP:
1199 val = llc->rej_sent_timer.expire / HZ; break;
1200 case LLC_OPT_BUSY_TMR_EXP:
1201 val = llc->busy_state_timer.expire / HZ; break;
1202 case LLC_OPT_TX_WIN:
1203 val = llc->k; break;
1204 case LLC_OPT_RX_WIN:
1205 val = llc->rw; break;
1206 case LLC_OPT_PKTINFO:
1207 val = (llc->cmsg_flags & LLC_CMSG_PKTINFO) != 0;
1208 break;
1209 default:
1210 rc = -ENOPROTOOPT;
1211 goto out;
1212 }
1213 rc = 0;
1214 if (put_user(len, optlen) || copy_to_user(optval, &val, len))
1215 rc = -EFAULT;
1216out:
1217 release_sock(sk);
1218 return rc;
1219}
1220
1221static const struct net_proto_family llc_ui_family_ops = {
1222 .family = PF_LLC,
1223 .create = llc_ui_create,
1224 .owner = THIS_MODULE,
1225};
1226
1227static const struct proto_ops llc_ui_ops = {
1228 .family = PF_LLC,
1229 .owner = THIS_MODULE,
1230 .release = llc_ui_release,
1231 .bind = llc_ui_bind,
1232 .connect = llc_ui_connect,
1233 .socketpair = sock_no_socketpair,
1234 .accept = llc_ui_accept,
1235 .getname = llc_ui_getname,
1236 .poll = datagram_poll,
1237 .ioctl = llc_ui_ioctl,
1238 .listen = llc_ui_listen,
1239 .shutdown = llc_ui_shutdown,
1240 .setsockopt = llc_ui_setsockopt,
1241 .getsockopt = llc_ui_getsockopt,
1242 .sendmsg = llc_ui_sendmsg,
1243 .recvmsg = llc_ui_recvmsg,
1244 .mmap = sock_no_mmap,
1245};
1246
1247static const char llc_proc_err_msg[] __initconst =
1248 KERN_CRIT "LLC: Unable to register the proc_fs entries\n";
1249static const char llc_sysctl_err_msg[] __initconst =
1250 KERN_CRIT "LLC: Unable to register the sysctl entries\n";
1251static const char llc_sock_err_msg[] __initconst =
1252 KERN_CRIT "LLC: Unable to register the network family\n";
1253
1254static int __init llc2_init(void)
1255{
1256 int rc = proto_register(&llc_proto, 0);
1257
1258 if (rc != 0)
1259 goto out;
1260
1261 llc_build_offset_table();
1262 llc_station_init();
1263 llc_ui_sap_last_autoport = LLC_SAP_DYN_START;
1264 rc = llc_proc_init();
1265 if (rc != 0) {
1266 printk(llc_proc_err_msg);
1267 goto out_station;
1268 }
1269 rc = llc_sysctl_init();
1270 if (rc) {
1271 printk(llc_sysctl_err_msg);
1272 goto out_proc;
1273 }
1274 rc = sock_register(&llc_ui_family_ops);
1275 if (rc) {
1276 printk(llc_sock_err_msg);
1277 goto out_sysctl;
1278 }
1279 llc_add_pack(LLC_DEST_SAP, llc_sap_handler);
1280 llc_add_pack(LLC_DEST_CONN, llc_conn_handler);
1281out:
1282 return rc;
1283out_sysctl:
1284 llc_sysctl_exit();
1285out_proc:
1286 llc_proc_exit();
1287out_station:
1288 llc_station_exit();
1289 proto_unregister(&llc_proto);
1290 goto out;
1291}
1292
1293static void __exit llc2_exit(void)
1294{
1295 llc_station_exit();
1296 llc_remove_pack(LLC_DEST_SAP);
1297 llc_remove_pack(LLC_DEST_CONN);
1298 sock_unregister(PF_LLC);
1299 llc_proc_exit();
1300 llc_sysctl_exit();
1301 proto_unregister(&llc_proto);
1302}
1303
1304module_init(llc2_init);
1305module_exit(llc2_exit);
1306
1307MODULE_LICENSE("GPL");
1308MODULE_AUTHOR("Procom 1997, Jay Schullist 2001, Arnaldo C. Melo 2001-2003");
1309MODULE_DESCRIPTION("IEEE 802.2 PF_LLC support");
1310MODULE_ALIAS_NETPROTO(PF_LLC);