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