Loading...
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 <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 bool 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 (!ns_capable(net->user_ns, 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, kern);
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 (is_zero_ether_addr(addr->sllc_mac))
325 memcpy(addr->sllc_mac, llc->dev->dev_addr,
326 IFHWADDRLEN);
327 if (addr->sllc_arphrd != llc->dev->type ||
328 !ether_addr_equal(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_FUNC(wait, woken_wake_function);
536 int rc = 0;
537
538 add_wait_queue(sk_sleep(sk), &wait);
539 while (1) {
540 if (sk_wait_event(sk, &timeout, sk->sk_state == TCP_CLOSE, &wait))
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 remove_wait_queue(sk_sleep(sk), &wait);
551 return rc;
552}
553
554static bool llc_ui_wait_for_conn(struct sock *sk, long timeout)
555{
556 DEFINE_WAIT_FUNC(wait, woken_wake_function);
557
558 add_wait_queue(sk_sleep(sk), &wait);
559 while (1) {
560 if (sk_wait_event(sk, &timeout, sk->sk_state != TCP_SYN_SENT, &wait))
561 break;
562 if (signal_pending(current) || !timeout)
563 break;
564 }
565 remove_wait_queue(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_FUNC(wait, woken_wake_function);
572 struct llc_sock *llc = llc_sk(sk);
573 int rc;
574
575 add_wait_queue(sk_sleep(sk), &wait);
576 while (1) {
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), &wait))
583 break;
584 rc = -ERESTARTSYS;
585 if (signal_pending(current))
586 break;
587 rc = -EAGAIN;
588 if (!timeout)
589 break;
590 }
591 remove_wait_queue(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, NULL))
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 memset(&info, 0, sizeof(info));
630 info.lpi_ifindex = llc_sk(skb->sk)->dev->ifindex;
631 llc_pdu_decode_dsap(skb, &info.lpi_sap);
632 llc_pdu_decode_da(skb, info.lpi_mac);
633 put_cmsg(msg, SOL_LLC, LLC_OPT_PKTINFO, sizeof(info), &info);
634 }
635}
636
637/**
638 * llc_ui_accept - accept a new incoming connection.
639 * @sock: Socket which connections arrive on.
640 * @newsock: Socket to move incoming connection to.
641 * @flags: User specified operational flags.
642 *
643 * Accept a new incoming connection.
644 * Returns 0 upon success, negative otherwise.
645 */
646static int llc_ui_accept(struct socket *sock, struct socket *newsock, int flags)
647{
648 struct sock *sk = sock->sk, *newsk;
649 struct llc_sock *llc, *newllc;
650 struct sk_buff *skb;
651 int rc = -EOPNOTSUPP;
652
653 dprintk("%s: accepting on %02X\n", __func__,
654 llc_sk(sk)->laddr.lsap);
655 lock_sock(sk);
656 if (unlikely(sk->sk_type != SOCK_STREAM))
657 goto out;
658 rc = -EINVAL;
659 if (unlikely(sock->state != SS_UNCONNECTED ||
660 sk->sk_state != TCP_LISTEN))
661 goto out;
662 /* wait for a connection to arrive. */
663 if (skb_queue_empty(&sk->sk_receive_queue)) {
664 rc = llc_wait_data(sk, sk->sk_rcvtimeo);
665 if (rc)
666 goto out;
667 }
668 dprintk("%s: got a new connection on %02X\n", __func__,
669 llc_sk(sk)->laddr.lsap);
670 skb = skb_dequeue(&sk->sk_receive_queue);
671 rc = -EINVAL;
672 if (!skb->sk)
673 goto frees;
674 rc = 0;
675 newsk = skb->sk;
676 /* attach connection to a new socket. */
677 llc_ui_sk_init(newsock, newsk);
678 sock_reset_flag(newsk, SOCK_ZAPPED);
679 newsk->sk_state = TCP_ESTABLISHED;
680 newsock->state = SS_CONNECTED;
681 llc = llc_sk(sk);
682 newllc = llc_sk(newsk);
683 memcpy(&newllc->addr, &llc->addr, sizeof(newllc->addr));
684 newllc->link = llc_ui_next_link_no(newllc->laddr.lsap);
685
686 /* put original socket back into a clean listen state. */
687 sk->sk_state = TCP_LISTEN;
688 sk->sk_ack_backlog--;
689 dprintk("%s: ok success on %02X, client on %02X\n", __func__,
690 llc_sk(sk)->addr.sllc_sap, newllc->daddr.lsap);
691frees:
692 kfree_skb(skb);
693out:
694 release_sock(sk);
695 return rc;
696}
697
698/**
699 * llc_ui_recvmsg - copy received data to the socket user.
700 * @sock: Socket to copy data from.
701 * @msg: Various user space related information.
702 * @len: Size of user buffer.
703 * @flags: User specified flags.
704 *
705 * Copy received data to the socket user.
706 * Returns non-negative upon success, negative otherwise.
707 */
708static int llc_ui_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
709 int flags)
710{
711 DECLARE_SOCKADDR(struct sockaddr_llc *, uaddr, msg->msg_name);
712 const int nonblock = flags & MSG_DONTWAIT;
713 struct sk_buff *skb = NULL;
714 struct sock *sk = sock->sk;
715 struct llc_sock *llc = llc_sk(sk);
716 unsigned long cpu_flags;
717 size_t copied = 0;
718 u32 peek_seq = 0;
719 u32 *seq, skb_len;
720 unsigned long used;
721 int target; /* Read at least this many bytes */
722 long timeo;
723
724 lock_sock(sk);
725 copied = -ENOTCONN;
726 if (unlikely(sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_LISTEN))
727 goto out;
728
729 timeo = sock_rcvtimeo(sk, nonblock);
730
731 seq = &llc->copied_seq;
732 if (flags & MSG_PEEK) {
733 peek_seq = llc->copied_seq;
734 seq = &peek_seq;
735 }
736
737 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
738 copied = 0;
739
740 do {
741 u32 offset;
742
743 /*
744 * We need to check signals first, to get correct SIGURG
745 * handling. FIXME: Need to check this doesn't impact 1003.1g
746 * and move it down to the bottom of the loop
747 */
748 if (signal_pending(current)) {
749 if (copied)
750 break;
751 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN;
752 break;
753 }
754
755 /* Next get a buffer. */
756
757 skb = skb_peek(&sk->sk_receive_queue);
758 if (skb) {
759 offset = *seq;
760 goto found_ok_skb;
761 }
762 /* Well, if we have backlog, try to process it now yet. */
763
764 if (copied >= target && !sk->sk_backlog.tail)
765 break;
766
767 if (copied) {
768 if (sk->sk_err ||
769 sk->sk_state == TCP_CLOSE ||
770 (sk->sk_shutdown & RCV_SHUTDOWN) ||
771 !timeo ||
772 (flags & MSG_PEEK))
773 break;
774 } else {
775 if (sock_flag(sk, SOCK_DONE))
776 break;
777
778 if (sk->sk_err) {
779 copied = sock_error(sk);
780 break;
781 }
782 if (sk->sk_shutdown & RCV_SHUTDOWN)
783 break;
784
785 if (sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_CLOSE) {
786 if (!sock_flag(sk, SOCK_DONE)) {
787 /*
788 * This occurs when user tries to read
789 * from never connected socket.
790 */
791 copied = -ENOTCONN;
792 break;
793 }
794 break;
795 }
796 if (!timeo) {
797 copied = -EAGAIN;
798 break;
799 }
800 }
801
802 if (copied >= target) { /* Do not sleep, just process backlog. */
803 release_sock(sk);
804 lock_sock(sk);
805 } else
806 sk_wait_data(sk, &timeo, NULL);
807
808 if ((flags & MSG_PEEK) && peek_seq != llc->copied_seq) {
809 net_dbg_ratelimited("LLC(%s:%d): Application bug, race in MSG_PEEK\n",
810 current->comm,
811 task_pid_nr(current));
812 peek_seq = llc->copied_seq;
813 }
814 continue;
815 found_ok_skb:
816 skb_len = skb->len;
817 /* Ok so how much can we use? */
818 used = skb->len - offset;
819 if (len < used)
820 used = len;
821
822 if (!(flags & MSG_TRUNC)) {
823 int rc = skb_copy_datagram_msg(skb, offset, msg, used);
824 if (rc) {
825 /* Exception. Bailout! */
826 if (!copied)
827 copied = -EFAULT;
828 break;
829 }
830 }
831
832 *seq += used;
833 copied += used;
834 len -= used;
835
836 /* For non stream protcols we get one packet per recvmsg call */
837 if (sk->sk_type != SOCK_STREAM)
838 goto copy_uaddr;
839
840 if (!(flags & MSG_PEEK)) {
841 spin_lock_irqsave(&sk->sk_receive_queue.lock, cpu_flags);
842 sk_eat_skb(sk, skb);
843 spin_unlock_irqrestore(&sk->sk_receive_queue.lock, cpu_flags);
844 *seq = 0;
845 }
846
847 /* Partial read */
848 if (used + offset < skb_len)
849 continue;
850 } while (len > 0);
851
852out:
853 release_sock(sk);
854 return copied;
855copy_uaddr:
856 if (uaddr != NULL && skb != NULL) {
857 memcpy(uaddr, llc_ui_skb_cb(skb), sizeof(*uaddr));
858 msg->msg_namelen = sizeof(*uaddr);
859 }
860 if (llc_sk(sk)->cmsg_flags)
861 llc_cmsg_rcv(msg, skb);
862
863 if (!(flags & MSG_PEEK)) {
864 spin_lock_irqsave(&sk->sk_receive_queue.lock, cpu_flags);
865 sk_eat_skb(sk, skb);
866 spin_unlock_irqrestore(&sk->sk_receive_queue.lock, cpu_flags);
867 *seq = 0;
868 }
869
870 goto out;
871}
872
873/**
874 * llc_ui_sendmsg - Transmit data provided by the socket user.
875 * @sock: Socket to transmit data from.
876 * @msg: Various user related information.
877 * @len: Length of data to transmit.
878 *
879 * Transmit data provided by the socket user.
880 * Returns non-negative upon success, negative otherwise.
881 */
882static int llc_ui_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
883{
884 struct sock *sk = sock->sk;
885 struct llc_sock *llc = llc_sk(sk);
886 DECLARE_SOCKADDR(struct sockaddr_llc *, addr, 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_from_msg(skb_put(skb, copied), msg, 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_station;
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_station:
1229 llc_station_exit();
1230 proto_unregister(&llc_proto);
1231 goto out;
1232}
1233
1234static void __exit llc2_exit(void)
1235{
1236 llc_station_exit();
1237 llc_remove_pack(LLC_DEST_SAP);
1238 llc_remove_pack(LLC_DEST_CONN);
1239 sock_unregister(PF_LLC);
1240 llc_proc_exit();
1241 llc_sysctl_exit();
1242 proto_unregister(&llc_proto);
1243}
1244
1245module_init(llc2_init);
1246module_exit(llc2_exit);
1247
1248MODULE_LICENSE("GPL");
1249MODULE_AUTHOR("Procom 1997, Jay Schullist 2001, Arnaldo C. Melo 2001-2003");
1250MODULE_DESCRIPTION("IEEE 802.2 PF_LLC support");
1251MODULE_ALIAS_NETPROTO(PF_LLC);