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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...) do {} while (0)
51#endif
52
53/* Maybe we'll add some more in the future. */
54#define LLC_CMSG_PKTINFO 1
55
56
57/**
58 * llc_ui_next_link_no - return the next unused link number for a sap
59 * @sap: Address of sap to get link number from.
60 *
61 * Return the next unused link number for a given sap.
62 */
63static inline u16 llc_ui_next_link_no(int sap)
64{
65 return llc_ui_sap_link_no_max[sap]++;
66}
67
68/**
69 * llc_proto_type - return eth protocol for ARP header type
70 * @arphrd: ARP header type.
71 *
72 * Given an ARP header type return the corresponding ethernet protocol.
73 */
74static inline __be16 llc_proto_type(u16 arphrd)
75{
76 return htons(ETH_P_802_2);
77}
78
79/**
80 * llc_ui_addr_null - determines if a address structure is null
81 * @addr: Address to test if null.
82 */
83static inline u8 llc_ui_addr_null(struct sockaddr_llc *addr)
84{
85 return !memcmp(addr, &llc_ui_addrnull, sizeof(*addr));
86}
87
88/**
89 * llc_ui_header_len - return length of llc header based on operation
90 * @sk: Socket which contains a valid llc socket type.
91 * @addr: Complete sockaddr_llc structure received from the user.
92 *
93 * Provide the length of the llc header depending on what kind of
94 * operation the user would like to perform and the type of socket.
95 * Returns the correct llc header length.
96 */
97static inline u8 llc_ui_header_len(struct sock *sk, struct sockaddr_llc *addr)
98{
99 u8 rc = LLC_PDU_LEN_U;
100
101 if (addr->sllc_test)
102 rc = LLC_PDU_LEN_U;
103 else if (addr->sllc_xid)
104 /* We need to expand header to sizeof(struct llc_xid_info)
105 * since llc_pdu_init_as_xid_cmd() sets 4,5,6 bytes of LLC header
106 * as XID PDU. In llc_ui_sendmsg() we reserved header size and then
107 * filled all other space with user data. If we won't reserve this
108 * bytes, llc_pdu_init_as_xid_cmd() will overwrite user data
109 */
110 rc = LLC_PDU_LEN_U_XID;
111 else if (sk->sk_type == SOCK_STREAM)
112 rc = LLC_PDU_LEN_I;
113 return rc;
114}
115
116/**
117 * llc_ui_send_data - send data via reliable llc2 connection
118 * @sk: Connection the socket is using.
119 * @skb: Data the user wishes to send.
120 * @noblock: can we block waiting for data?
121 *
122 * Send data via reliable llc2 connection.
123 * Returns 0 upon success, non-zero if action did not succeed.
124 *
125 * This function always consumes a reference to the skb.
126 */
127static int llc_ui_send_data(struct sock* sk, struct sk_buff *skb, int noblock)
128{
129 struct llc_sock* llc = llc_sk(sk);
130
131 if (unlikely(llc_data_accept_state(llc->state) ||
132 llc->remote_busy_flag ||
133 llc->p_flag)) {
134 long timeout = sock_sndtimeo(sk, noblock);
135 int rc;
136
137 rc = llc_ui_wait_for_busy_core(sk, timeout);
138 if (rc) {
139 kfree_skb(skb);
140 return rc;
141 }
142 }
143 return llc_build_and_send_pkt(sk, skb);
144}
145
146static void llc_ui_sk_init(struct socket *sock, struct sock *sk)
147{
148 sock_graft(sk, sock);
149 sk->sk_type = sock->type;
150 sock->ops = &llc_ui_ops;
151}
152
153static struct proto llc_proto = {
154 .name = "LLC",
155 .owner = THIS_MODULE,
156 .obj_size = sizeof(struct llc_sock),
157 .slab_flags = SLAB_TYPESAFE_BY_RCU,
158};
159
160/**
161 * llc_ui_create - alloc and init a new llc_ui socket
162 * @net: network namespace (must be default network)
163 * @sock: Socket to initialize and attach allocated sk to.
164 * @protocol: Unused.
165 * @kern: on behalf of kernel or userspace
166 *
167 * Allocate and initialize a new llc_ui socket, validate the user wants a
168 * socket type we have available.
169 * Returns 0 upon success, negative upon failure.
170 */
171static int llc_ui_create(struct net *net, struct socket *sock, int protocol,
172 int kern)
173{
174 struct sock *sk;
175 int rc = -ESOCKTNOSUPPORT;
176
177 if (!ns_capable(net->user_ns, CAP_NET_RAW))
178 return -EPERM;
179
180 if (!net_eq(net, &init_net))
181 return -EAFNOSUPPORT;
182
183 if (likely(sock->type == SOCK_DGRAM || sock->type == SOCK_STREAM)) {
184 rc = -ENOMEM;
185 sk = llc_sk_alloc(net, PF_LLC, GFP_KERNEL, &llc_proto, kern);
186 if (sk) {
187 rc = 0;
188 llc_ui_sk_init(sock, sk);
189 }
190 }
191 return rc;
192}
193
194/**
195 * llc_ui_release - shutdown socket
196 * @sock: Socket to release.
197 *
198 * Shutdown and deallocate an existing socket.
199 */
200static int llc_ui_release(struct socket *sock)
201{
202 struct sock *sk = sock->sk;
203 struct llc_sock *llc;
204
205 if (unlikely(sk == NULL))
206 goto out;
207 sock_hold(sk);
208 lock_sock(sk);
209 llc = llc_sk(sk);
210 dprintk("%s: closing local(%02X) remote(%02X)\n", __func__,
211 llc->laddr.lsap, llc->daddr.lsap);
212 if (!llc_send_disc(sk))
213 llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo);
214 if (!sock_flag(sk, SOCK_ZAPPED)) {
215 struct llc_sap *sap = llc->sap;
216
217 /* Hold this for release_sock(), so that llc_backlog_rcv()
218 * could still use it.
219 */
220 llc_sap_hold(sap);
221 llc_sap_remove_socket(llc->sap, sk);
222 release_sock(sk);
223 llc_sap_put(sap);
224 } else {
225 release_sock(sk);
226 }
227 netdev_put(llc->dev, &llc->dev_tracker);
228 sock_put(sk);
229 sock_orphan(sk);
230 sock->sk = NULL;
231 llc_sk_free(sk);
232out:
233 return 0;
234}
235
236/**
237 * llc_ui_autoport - provide dynamically allocate SAP number
238 *
239 * Provide the caller with a dynamically allocated SAP number according
240 * to the rules that are set in this function. Returns: 0, upon failure,
241 * SAP number otherwise.
242 */
243static int llc_ui_autoport(void)
244{
245 struct llc_sap *sap;
246 int i, tries = 0;
247
248 while (tries < LLC_SAP_DYN_TRIES) {
249 for (i = llc_ui_sap_last_autoport;
250 i < LLC_SAP_DYN_STOP; i += 2) {
251 sap = llc_sap_find(i);
252 if (!sap) {
253 llc_ui_sap_last_autoport = i + 2;
254 goto out;
255 }
256 llc_sap_put(sap);
257 }
258 llc_ui_sap_last_autoport = LLC_SAP_DYN_START;
259 tries++;
260 }
261 i = 0;
262out:
263 return i;
264}
265
266/**
267 * llc_ui_autobind - automatically bind a socket to a sap
268 * @sock: socket to bind
269 * @addr: address to connect to
270 *
271 * Used by llc_ui_connect and llc_ui_sendmsg when the user hasn't
272 * specifically used llc_ui_bind to bind to an specific address/sap
273 *
274 * Returns: 0 upon success, negative otherwise.
275 */
276static int llc_ui_autobind(struct socket *sock, struct sockaddr_llc *addr)
277{
278 struct sock *sk = sock->sk;
279 struct llc_sock *llc = llc_sk(sk);
280 struct net_device *dev = NULL;
281 struct llc_sap *sap;
282 int rc = -EINVAL;
283
284 if (!sock_flag(sk, SOCK_ZAPPED))
285 goto out;
286 if (!addr->sllc_arphrd)
287 addr->sllc_arphrd = ARPHRD_ETHER;
288 if (addr->sllc_arphrd != ARPHRD_ETHER)
289 goto out;
290 rc = -ENODEV;
291 if (sk->sk_bound_dev_if) {
292 dev = dev_get_by_index(&init_net, sk->sk_bound_dev_if);
293 if (dev && addr->sllc_arphrd != dev->type) {
294 dev_put(dev);
295 dev = NULL;
296 }
297 } else
298 dev = dev_getfirstbyhwtype(&init_net, addr->sllc_arphrd);
299 if (!dev)
300 goto out;
301 rc = -EUSERS;
302 llc->laddr.lsap = llc_ui_autoport();
303 if (!llc->laddr.lsap)
304 goto out;
305 rc = -EBUSY; /* some other network layer is using the sap */
306 sap = llc_sap_open(llc->laddr.lsap, NULL);
307 if (!sap)
308 goto out;
309
310 /* Note: We do not expect errors from this point. */
311 llc->dev = dev;
312 netdev_tracker_alloc(llc->dev, &llc->dev_tracker, GFP_KERNEL);
313 dev = NULL;
314
315 memcpy(llc->laddr.mac, llc->dev->dev_addr, IFHWADDRLEN);
316 memcpy(&llc->addr, addr, sizeof(llc->addr));
317 /* assign new connection to its SAP */
318 llc_sap_add_socket(sap, sk);
319 sock_reset_flag(sk, SOCK_ZAPPED);
320 rc = 0;
321out:
322 dev_put(dev);
323 return rc;
324}
325
326/**
327 * llc_ui_bind - bind a socket to a specific address.
328 * @sock: Socket to bind an address to.
329 * @uaddr: Address the user wants the socket bound to.
330 * @addrlen: Length of the uaddr structure.
331 *
332 * Bind a socket to a specific address. For llc a user is able to bind to
333 * a specific sap only or mac + sap.
334 * If the user desires to bind to a specific mac + sap, it is possible to
335 * have multiple sap connections via multiple macs.
336 * Bind and autobind for that matter must enforce the correct sap usage
337 * otherwise all hell will break loose.
338 * Returns: 0 upon success, negative otherwise.
339 */
340static int llc_ui_bind(struct socket *sock, struct sockaddr *uaddr, int addrlen)
341{
342 struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr;
343 struct sock *sk = sock->sk;
344 struct llc_sock *llc = llc_sk(sk);
345 struct net_device *dev = NULL;
346 struct llc_sap *sap;
347 int rc = -EINVAL;
348
349 lock_sock(sk);
350 if (unlikely(!sock_flag(sk, SOCK_ZAPPED) || addrlen != sizeof(*addr)))
351 goto out;
352 rc = -EAFNOSUPPORT;
353 if (!addr->sllc_arphrd)
354 addr->sllc_arphrd = ARPHRD_ETHER;
355 if (unlikely(addr->sllc_family != AF_LLC || addr->sllc_arphrd != ARPHRD_ETHER))
356 goto out;
357 dprintk("%s: binding %02X\n", __func__, addr->sllc_sap);
358 rc = -ENODEV;
359 rcu_read_lock();
360 if (sk->sk_bound_dev_if) {
361 dev = dev_get_by_index_rcu(&init_net, sk->sk_bound_dev_if);
362 if (dev) {
363 if (is_zero_ether_addr(addr->sllc_mac))
364 memcpy(addr->sllc_mac, dev->dev_addr,
365 IFHWADDRLEN);
366 if (addr->sllc_arphrd != dev->type ||
367 !ether_addr_equal(addr->sllc_mac,
368 dev->dev_addr)) {
369 rc = -EINVAL;
370 dev = NULL;
371 }
372 }
373 } else {
374 dev = dev_getbyhwaddr_rcu(&init_net, addr->sllc_arphrd,
375 addr->sllc_mac);
376 }
377 dev_hold(dev);
378 rcu_read_unlock();
379 if (!dev)
380 goto out;
381
382 if (!addr->sllc_sap) {
383 rc = -EUSERS;
384 addr->sllc_sap = llc_ui_autoport();
385 if (!addr->sllc_sap)
386 goto out;
387 }
388 sap = llc_sap_find(addr->sllc_sap);
389 if (!sap) {
390 sap = llc_sap_open(addr->sllc_sap, NULL);
391 rc = -EBUSY; /* some other network layer is using the sap */
392 if (!sap)
393 goto out;
394 } else {
395 struct llc_addr laddr, daddr;
396 struct sock *ask;
397
398 memset(&laddr, 0, sizeof(laddr));
399 memset(&daddr, 0, sizeof(daddr));
400 /*
401 * FIXME: check if the address is multicast,
402 * only SOCK_DGRAM can do this.
403 */
404 memcpy(laddr.mac, addr->sllc_mac, IFHWADDRLEN);
405 laddr.lsap = addr->sllc_sap;
406 rc = -EADDRINUSE; /* mac + sap clash. */
407 ask = llc_lookup_established(sap, &daddr, &laddr, &init_net);
408 if (ask) {
409 sock_put(ask);
410 goto out_put;
411 }
412 }
413
414 /* Note: We do not expect errors from this point. */
415 llc->dev = dev;
416 netdev_tracker_alloc(llc->dev, &llc->dev_tracker, GFP_KERNEL);
417 dev = NULL;
418
419 llc->laddr.lsap = addr->sllc_sap;
420 memcpy(llc->laddr.mac, addr->sllc_mac, IFHWADDRLEN);
421 memcpy(&llc->addr, addr, sizeof(llc->addr));
422 /* assign new connection to its SAP */
423 llc_sap_add_socket(sap, sk);
424 sock_reset_flag(sk, SOCK_ZAPPED);
425 rc = 0;
426out_put:
427 llc_sap_put(sap);
428out:
429 dev_put(dev);
430 release_sock(sk);
431 return rc;
432}
433
434/**
435 * llc_ui_shutdown - shutdown a connect llc2 socket.
436 * @sock: Socket to shutdown.
437 * @how: What part of the socket to shutdown.
438 *
439 * Shutdown a connected llc2 socket. Currently this function only supports
440 * shutting down both sends and receives (2), we could probably make this
441 * function such that a user can shutdown only half the connection but not
442 * right now.
443 * Returns: 0 upon success, negative otherwise.
444 */
445static int llc_ui_shutdown(struct socket *sock, int how)
446{
447 struct sock *sk = sock->sk;
448 int rc = -ENOTCONN;
449
450 lock_sock(sk);
451 if (unlikely(sk->sk_state != TCP_ESTABLISHED))
452 goto out;
453 rc = -EINVAL;
454 if (how != 2)
455 goto out;
456 rc = llc_send_disc(sk);
457 if (!rc)
458 rc = llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo);
459 /* Wake up anyone sleeping in poll */
460 sk->sk_state_change(sk);
461out:
462 release_sock(sk);
463 return rc;
464}
465
466/**
467 * llc_ui_connect - Connect to a remote llc2 mac + sap.
468 * @sock: Socket which will be connected to the remote destination.
469 * @uaddr: Remote and possibly the local address of the new connection.
470 * @addrlen: Size of uaddr structure.
471 * @flags: Operational flags specified by the user.
472 *
473 * Connect to a remote llc2 mac + sap. The caller must specify the
474 * destination mac and address to connect to. If the user hasn't previously
475 * called bind(2) with a smac the address of the first interface of the
476 * specified arp type will be used.
477 * This function will autobind if user did not previously call bind.
478 * Returns: 0 upon success, negative otherwise.
479 */
480static int llc_ui_connect(struct socket *sock, struct sockaddr *uaddr,
481 int addrlen, int flags)
482{
483 struct sock *sk = sock->sk;
484 struct llc_sock *llc = llc_sk(sk);
485 struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr;
486 int rc = -EINVAL;
487
488 lock_sock(sk);
489 if (unlikely(addrlen != sizeof(*addr)))
490 goto out;
491 rc = -EAFNOSUPPORT;
492 if (unlikely(addr->sllc_family != AF_LLC))
493 goto out;
494 if (unlikely(sk->sk_type != SOCK_STREAM))
495 goto out;
496 rc = -EALREADY;
497 if (unlikely(sock->state == SS_CONNECTING))
498 goto out;
499 /* bind connection to sap if user hasn't done it. */
500 if (sock_flag(sk, SOCK_ZAPPED)) {
501 /* bind to sap with null dev, exclusive */
502 rc = llc_ui_autobind(sock, addr);
503 if (rc)
504 goto out;
505 }
506 llc->daddr.lsap = addr->sllc_sap;
507 memcpy(llc->daddr.mac, addr->sllc_mac, IFHWADDRLEN);
508 sock->state = SS_CONNECTING;
509 sk->sk_state = TCP_SYN_SENT;
510 llc->link = llc_ui_next_link_no(llc->sap->laddr.lsap);
511 rc = llc_establish_connection(sk, llc->dev->dev_addr,
512 addr->sllc_mac, addr->sllc_sap);
513 if (rc) {
514 dprintk("%s: llc_ui_send_conn failed :-(\n", __func__);
515 sock->state = SS_UNCONNECTED;
516 sk->sk_state = TCP_CLOSE;
517 goto out;
518 }
519
520 if (sk->sk_state == TCP_SYN_SENT) {
521 const long timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
522
523 if (!timeo || !llc_ui_wait_for_conn(sk, timeo))
524 goto out;
525
526 rc = sock_intr_errno(timeo);
527 if (signal_pending(current))
528 goto out;
529 }
530
531 if (sk->sk_state == TCP_CLOSE)
532 goto sock_error;
533
534 sock->state = SS_CONNECTED;
535 rc = 0;
536out:
537 release_sock(sk);
538 return rc;
539sock_error:
540 rc = sock_error(sk) ? : -ECONNABORTED;
541 sock->state = SS_UNCONNECTED;
542 goto out;
543}
544
545/**
546 * llc_ui_listen - allow a normal socket to accept incoming connections
547 * @sock: Socket to allow incoming connections on.
548 * @backlog: Number of connections to queue.
549 *
550 * Allow a normal socket to accept incoming connections.
551 * Returns 0 upon success, negative otherwise.
552 */
553static int llc_ui_listen(struct socket *sock, int backlog)
554{
555 struct sock *sk = sock->sk;
556 int rc = -EINVAL;
557
558 lock_sock(sk);
559 if (unlikely(sock->state != SS_UNCONNECTED))
560 goto out;
561 rc = -EOPNOTSUPP;
562 if (unlikely(sk->sk_type != SOCK_STREAM))
563 goto out;
564 rc = -EAGAIN;
565 if (sock_flag(sk, SOCK_ZAPPED))
566 goto out;
567 rc = 0;
568 if (!(unsigned int)backlog) /* BSDism */
569 backlog = 1;
570 sk->sk_max_ack_backlog = backlog;
571 if (sk->sk_state != TCP_LISTEN) {
572 sk->sk_ack_backlog = 0;
573 sk->sk_state = TCP_LISTEN;
574 }
575 sk->sk_socket->flags |= __SO_ACCEPTCON;
576out:
577 release_sock(sk);
578 return rc;
579}
580
581static int llc_ui_wait_for_disc(struct sock *sk, long timeout)
582{
583 DEFINE_WAIT_FUNC(wait, woken_wake_function);
584 int rc = 0;
585
586 add_wait_queue(sk_sleep(sk), &wait);
587 while (1) {
588 if (sk_wait_event(sk, &timeout,
589 READ_ONCE(sk->sk_state) == TCP_CLOSE, &wait))
590 break;
591 rc = -ERESTARTSYS;
592 if (signal_pending(current))
593 break;
594 rc = -EAGAIN;
595 if (!timeout)
596 break;
597 rc = 0;
598 }
599 remove_wait_queue(sk_sleep(sk), &wait);
600 return rc;
601}
602
603static bool llc_ui_wait_for_conn(struct sock *sk, long timeout)
604{
605 DEFINE_WAIT_FUNC(wait, woken_wake_function);
606
607 add_wait_queue(sk_sleep(sk), &wait);
608 while (1) {
609 if (sk_wait_event(sk, &timeout,
610 READ_ONCE(sk->sk_state) != TCP_SYN_SENT, &wait))
611 break;
612 if (signal_pending(current) || !timeout)
613 break;
614 }
615 remove_wait_queue(sk_sleep(sk), &wait);
616 return timeout;
617}
618
619static int llc_ui_wait_for_busy_core(struct sock *sk, long timeout)
620{
621 DEFINE_WAIT_FUNC(wait, woken_wake_function);
622 struct llc_sock *llc = llc_sk(sk);
623 int rc;
624
625 add_wait_queue(sk_sleep(sk), &wait);
626 while (1) {
627 rc = 0;
628 if (sk_wait_event(sk, &timeout,
629 (READ_ONCE(sk->sk_shutdown) & RCV_SHUTDOWN) ||
630 (!llc_data_accept_state(llc->state) &&
631 !llc->remote_busy_flag &&
632 !llc->p_flag), &wait))
633 break;
634 rc = -ERESTARTSYS;
635 if (signal_pending(current))
636 break;
637 rc = -EAGAIN;
638 if (!timeout)
639 break;
640 }
641 remove_wait_queue(sk_sleep(sk), &wait);
642 return rc;
643}
644
645static int llc_wait_data(struct sock *sk, long timeo)
646{
647 int rc;
648
649 while (1) {
650 /*
651 * POSIX 1003.1g mandates this order.
652 */
653 rc = sock_error(sk);
654 if (rc)
655 break;
656 rc = 0;
657 if (sk->sk_shutdown & RCV_SHUTDOWN)
658 break;
659 rc = -EAGAIN;
660 if (!timeo)
661 break;
662 rc = sock_intr_errno(timeo);
663 if (signal_pending(current))
664 break;
665 rc = 0;
666 if (sk_wait_data(sk, &timeo, NULL))
667 break;
668 }
669 return rc;
670}
671
672static void llc_cmsg_rcv(struct msghdr *msg, struct sk_buff *skb)
673{
674 struct llc_sock *llc = llc_sk(skb->sk);
675
676 if (llc->cmsg_flags & LLC_CMSG_PKTINFO) {
677 struct llc_pktinfo info;
678
679 memset(&info, 0, sizeof(info));
680 info.lpi_ifindex = llc_sk(skb->sk)->dev->ifindex;
681 llc_pdu_decode_dsap(skb, &info.lpi_sap);
682 llc_pdu_decode_da(skb, info.lpi_mac);
683 put_cmsg(msg, SOL_LLC, LLC_OPT_PKTINFO, sizeof(info), &info);
684 }
685}
686
687/**
688 * llc_ui_accept - accept a new incoming connection.
689 * @sock: Socket which connections arrive on.
690 * @newsock: Socket to move incoming connection to.
691 * @arg: User specified arguments
692 *
693 * Accept a new incoming connection.
694 * Returns 0 upon success, negative otherwise.
695 */
696static int llc_ui_accept(struct socket *sock, struct socket *newsock,
697 struct proto_accept_arg *arg)
698{
699 struct sock *sk = sock->sk, *newsk;
700 struct llc_sock *llc, *newllc;
701 struct sk_buff *skb;
702 int rc = -EOPNOTSUPP;
703
704 dprintk("%s: accepting on %02X\n", __func__,
705 llc_sk(sk)->laddr.lsap);
706 lock_sock(sk);
707 if (unlikely(sk->sk_type != SOCK_STREAM))
708 goto out;
709 rc = -EINVAL;
710 if (unlikely(sock->state != SS_UNCONNECTED ||
711 sk->sk_state != TCP_LISTEN))
712 goto out;
713 /* wait for a connection to arrive. */
714 if (skb_queue_empty(&sk->sk_receive_queue)) {
715 rc = llc_wait_data(sk, sk->sk_rcvtimeo);
716 if (rc)
717 goto out;
718 }
719 dprintk("%s: got a new connection on %02X\n", __func__,
720 llc_sk(sk)->laddr.lsap);
721 skb = skb_dequeue(&sk->sk_receive_queue);
722 rc = -EINVAL;
723 if (!skb->sk)
724 goto frees;
725 rc = 0;
726 newsk = skb->sk;
727 /* attach connection to a new socket. */
728 llc_ui_sk_init(newsock, newsk);
729 sock_reset_flag(newsk, SOCK_ZAPPED);
730 newsk->sk_state = TCP_ESTABLISHED;
731 newsock->state = SS_CONNECTED;
732 llc = llc_sk(sk);
733 newllc = llc_sk(newsk);
734 memcpy(&newllc->addr, &llc->addr, sizeof(newllc->addr));
735 newllc->link = llc_ui_next_link_no(newllc->laddr.lsap);
736
737 /* put original socket back into a clean listen state. */
738 sk->sk_state = TCP_LISTEN;
739 sk_acceptq_removed(sk);
740 dprintk("%s: ok success on %02X, client on %02X\n", __func__,
741 llc_sk(sk)->addr.sllc_sap, newllc->daddr.lsap);
742frees:
743 kfree_skb(skb);
744out:
745 release_sock(sk);
746 return rc;
747}
748
749/**
750 * llc_ui_recvmsg - copy received data to the socket user.
751 * @sock: Socket to copy data from.
752 * @msg: Various user space related information.
753 * @len: Size of user buffer.
754 * @flags: User specified flags.
755 *
756 * Copy received data to the socket user.
757 * Returns non-negative upon success, negative otherwise.
758 */
759static int llc_ui_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
760 int flags)
761{
762 DECLARE_SOCKADDR(struct sockaddr_llc *, uaddr, msg->msg_name);
763 const int nonblock = flags & MSG_DONTWAIT;
764 struct sk_buff *skb = NULL;
765 struct sock *sk = sock->sk;
766 struct llc_sock *llc = llc_sk(sk);
767 size_t copied = 0;
768 u32 peek_seq = 0;
769 u32 *seq, skb_len;
770 unsigned long used;
771 int target; /* Read at least this many bytes */
772 long timeo;
773
774 lock_sock(sk);
775 copied = -ENOTCONN;
776 if (unlikely(sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_LISTEN))
777 goto out;
778
779 timeo = sock_rcvtimeo(sk, nonblock);
780
781 seq = &llc->copied_seq;
782 if (flags & MSG_PEEK) {
783 peek_seq = llc->copied_seq;
784 seq = &peek_seq;
785 }
786
787 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
788 copied = 0;
789
790 do {
791 u32 offset;
792
793 /*
794 * We need to check signals first, to get correct SIGURG
795 * handling. FIXME: Need to check this doesn't impact 1003.1g
796 * and move it down to the bottom of the loop
797 */
798 if (signal_pending(current)) {
799 if (copied)
800 break;
801 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN;
802 break;
803 }
804
805 /* Next get a buffer. */
806
807 skb = skb_peek(&sk->sk_receive_queue);
808 if (skb) {
809 offset = *seq;
810 goto found_ok_skb;
811 }
812 /* Well, if we have backlog, try to process it now yet. */
813
814 if (copied >= target && !READ_ONCE(sk->sk_backlog.tail))
815 break;
816
817 if (copied) {
818 if (sk->sk_err ||
819 sk->sk_state == TCP_CLOSE ||
820 (sk->sk_shutdown & RCV_SHUTDOWN) ||
821 !timeo ||
822 (flags & MSG_PEEK))
823 break;
824 } else {
825 if (sock_flag(sk, SOCK_DONE))
826 break;
827
828 if (sk->sk_err) {
829 copied = sock_error(sk);
830 break;
831 }
832 if (sk->sk_shutdown & RCV_SHUTDOWN)
833 break;
834
835 if (sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_CLOSE) {
836 if (!sock_flag(sk, SOCK_DONE)) {
837 /*
838 * This occurs when user tries to read
839 * from never connected socket.
840 */
841 copied = -ENOTCONN;
842 break;
843 }
844 break;
845 }
846 if (!timeo) {
847 copied = -EAGAIN;
848 break;
849 }
850 }
851
852 if (copied >= target) { /* Do not sleep, just process backlog. */
853 release_sock(sk);
854 lock_sock(sk);
855 } else
856 sk_wait_data(sk, &timeo, NULL);
857
858 if ((flags & MSG_PEEK) && peek_seq != llc->copied_seq) {
859 net_dbg_ratelimited("LLC(%s:%d): Application bug, race in MSG_PEEK\n",
860 current->comm,
861 task_pid_nr(current));
862 peek_seq = llc->copied_seq;
863 }
864 continue;
865 found_ok_skb:
866 skb_len = skb->len;
867 /* Ok so how much can we use? */
868 used = skb->len - offset;
869 if (len < used)
870 used = len;
871
872 if (!(flags & MSG_TRUNC)) {
873 int rc = skb_copy_datagram_msg(skb, offset, msg, used);
874 if (rc) {
875 /* Exception. Bailout! */
876 if (!copied)
877 copied = -EFAULT;
878 break;
879 }
880 }
881
882 *seq += used;
883 copied += used;
884 len -= used;
885
886 /* For non stream protcols we get one packet per recvmsg call */
887 if (sk->sk_type != SOCK_STREAM)
888 goto copy_uaddr;
889
890 if (!(flags & MSG_PEEK)) {
891 skb_unlink(skb, &sk->sk_receive_queue);
892 kfree_skb(skb);
893 *seq = 0;
894 }
895
896 /* Partial read */
897 if (used + offset < skb_len)
898 continue;
899 } while (len > 0);
900
901out:
902 release_sock(sk);
903 return copied;
904copy_uaddr:
905 if (uaddr != NULL && skb != NULL) {
906 memcpy(uaddr, llc_ui_skb_cb(skb), sizeof(*uaddr));
907 msg->msg_namelen = sizeof(*uaddr);
908 }
909 if (llc_sk(sk)->cmsg_flags)
910 llc_cmsg_rcv(msg, skb);
911
912 if (!(flags & MSG_PEEK)) {
913 skb_unlink(skb, &sk->sk_receive_queue);
914 kfree_skb(skb);
915 *seq = 0;
916 }
917
918 goto out;
919}
920
921/**
922 * llc_ui_sendmsg - Transmit data provided by the socket user.
923 * @sock: Socket to transmit data from.
924 * @msg: Various user related information.
925 * @len: Length of data to transmit.
926 *
927 * Transmit data provided by the socket user.
928 * Returns non-negative upon success, negative otherwise.
929 */
930static int llc_ui_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
931{
932 DECLARE_SOCKADDR(struct sockaddr_llc *, addr, msg->msg_name);
933 struct sock *sk = sock->sk;
934 struct llc_sock *llc = llc_sk(sk);
935 int flags = msg->msg_flags;
936 int noblock = flags & MSG_DONTWAIT;
937 int rc = -EINVAL, copied = 0, hdrlen, hh_len;
938 struct sk_buff *skb = NULL;
939 struct net_device *dev;
940 size_t size = 0;
941
942 dprintk("%s: sending from %02X to %02X\n", __func__,
943 llc->laddr.lsap, llc->daddr.lsap);
944 lock_sock(sk);
945 if (addr) {
946 if (msg->msg_namelen < sizeof(*addr))
947 goto out;
948 } else {
949 if (llc_ui_addr_null(&llc->addr))
950 goto out;
951 addr = &llc->addr;
952 }
953 /* must bind connection to sap if user hasn't done it. */
954 if (sock_flag(sk, SOCK_ZAPPED)) {
955 /* bind to sap with null dev, exclusive. */
956 rc = llc_ui_autobind(sock, addr);
957 if (rc)
958 goto out;
959 }
960 dev = llc->dev;
961 hh_len = LL_RESERVED_SPACE(dev);
962 hdrlen = llc_ui_header_len(sk, addr);
963 size = hdrlen + len;
964 size = min_t(size_t, size, READ_ONCE(dev->mtu));
965 copied = size - hdrlen;
966 rc = -EINVAL;
967 if (copied < 0)
968 goto out;
969 release_sock(sk);
970 skb = sock_alloc_send_skb(sk, hh_len + size, noblock, &rc);
971 lock_sock(sk);
972 if (!skb)
973 goto out;
974 if (sock_flag(sk, SOCK_ZAPPED) ||
975 llc->dev != dev ||
976 hdrlen != llc_ui_header_len(sk, addr) ||
977 hh_len != LL_RESERVED_SPACE(dev) ||
978 size > READ_ONCE(dev->mtu))
979 goto out;
980 skb->dev = dev;
981 skb->protocol = llc_proto_type(addr->sllc_arphrd);
982 skb_reserve(skb, hh_len + hdrlen);
983 rc = memcpy_from_msg(skb_put(skb, copied), msg, copied);
984 if (rc)
985 goto out;
986 if (sk->sk_type == SOCK_DGRAM || addr->sllc_ua) {
987 llc_build_and_send_ui_pkt(llc->sap, skb, addr->sllc_mac,
988 addr->sllc_sap);
989 skb = NULL;
990 goto out;
991 }
992 if (addr->sllc_test) {
993 llc_build_and_send_test_pkt(llc->sap, skb, addr->sllc_mac,
994 addr->sllc_sap);
995 skb = NULL;
996 goto out;
997 }
998 if (addr->sllc_xid) {
999 llc_build_and_send_xid_pkt(llc->sap, skb, addr->sllc_mac,
1000 addr->sllc_sap);
1001 skb = NULL;
1002 goto out;
1003 }
1004 rc = -ENOPROTOOPT;
1005 if (!(sk->sk_type == SOCK_STREAM && !addr->sllc_ua))
1006 goto out;
1007 rc = llc_ui_send_data(sk, skb, noblock);
1008 skb = NULL;
1009out:
1010 kfree_skb(skb);
1011 if (rc)
1012 dprintk("%s: failed sending from %02X to %02X: %d\n",
1013 __func__, llc->laddr.lsap, llc->daddr.lsap, rc);
1014 release_sock(sk);
1015 return rc ? : copied;
1016}
1017
1018/**
1019 * llc_ui_getname - return the address info of a socket
1020 * @sock: Socket to get address of.
1021 * @uaddr: Address structure to return information.
1022 * @peer: Does user want local or remote address information.
1023 *
1024 * Return the address information of a socket.
1025 */
1026static int llc_ui_getname(struct socket *sock, struct sockaddr *uaddr,
1027 int peer)
1028{
1029 struct sockaddr_llc sllc;
1030 struct sock *sk = sock->sk;
1031 struct llc_sock *llc = llc_sk(sk);
1032 int rc = -EBADF;
1033
1034 memset(&sllc, 0, sizeof(sllc));
1035 lock_sock(sk);
1036 if (sock_flag(sk, SOCK_ZAPPED))
1037 goto out;
1038 if (peer) {
1039 rc = -ENOTCONN;
1040 if (sk->sk_state != TCP_ESTABLISHED)
1041 goto out;
1042 if(llc->dev)
1043 sllc.sllc_arphrd = llc->dev->type;
1044 sllc.sllc_sap = llc->daddr.lsap;
1045 memcpy(&sllc.sllc_mac, &llc->daddr.mac, IFHWADDRLEN);
1046 } else {
1047 rc = -EINVAL;
1048 if (!llc->sap)
1049 goto out;
1050 sllc.sllc_sap = llc->sap->laddr.lsap;
1051
1052 if (llc->dev) {
1053 sllc.sllc_arphrd = llc->dev->type;
1054 memcpy(&sllc.sllc_mac, llc->dev->dev_addr,
1055 IFHWADDRLEN);
1056 }
1057 }
1058 sllc.sllc_family = AF_LLC;
1059 memcpy(uaddr, &sllc, sizeof(sllc));
1060 rc = sizeof(sllc);
1061out:
1062 release_sock(sk);
1063 return rc;
1064}
1065
1066/**
1067 * llc_ui_ioctl - io controls for PF_LLC
1068 * @sock: Socket to get/set info
1069 * @cmd: command
1070 * @arg: optional argument for cmd
1071 *
1072 * get/set info on llc sockets
1073 */
1074static int llc_ui_ioctl(struct socket *sock, unsigned int cmd,
1075 unsigned long arg)
1076{
1077 return -ENOIOCTLCMD;
1078}
1079
1080/**
1081 * llc_ui_setsockopt - set various connection specific parameters.
1082 * @sock: Socket to set options on.
1083 * @level: Socket level user is requesting operations on.
1084 * @optname: Operation name.
1085 * @optval: User provided operation data.
1086 * @optlen: Length of optval.
1087 *
1088 * Set various connection specific parameters.
1089 */
1090static int llc_ui_setsockopt(struct socket *sock, int level, int optname,
1091 sockptr_t optval, unsigned int optlen)
1092{
1093 struct sock *sk = sock->sk;
1094 struct llc_sock *llc = llc_sk(sk);
1095 unsigned int opt;
1096 int rc = -EINVAL;
1097
1098 lock_sock(sk);
1099 if (unlikely(level != SOL_LLC || optlen != sizeof(int)))
1100 goto out;
1101 rc = copy_safe_from_sockptr(&opt, sizeof(opt), optval, optlen);
1102 if (rc)
1103 goto out;
1104 rc = -EINVAL;
1105 switch (optname) {
1106 case LLC_OPT_RETRY:
1107 if (opt > LLC_OPT_MAX_RETRY)
1108 goto out;
1109 llc->n2 = opt;
1110 break;
1111 case LLC_OPT_SIZE:
1112 if (opt > LLC_OPT_MAX_SIZE)
1113 goto out;
1114 llc->n1 = opt;
1115 break;
1116 case LLC_OPT_ACK_TMR_EXP:
1117 if (opt > LLC_OPT_MAX_ACK_TMR_EXP)
1118 goto out;
1119 llc->ack_timer.expire = opt * HZ;
1120 break;
1121 case LLC_OPT_P_TMR_EXP:
1122 if (opt > LLC_OPT_MAX_P_TMR_EXP)
1123 goto out;
1124 llc->pf_cycle_timer.expire = opt * HZ;
1125 break;
1126 case LLC_OPT_REJ_TMR_EXP:
1127 if (opt > LLC_OPT_MAX_REJ_TMR_EXP)
1128 goto out;
1129 llc->rej_sent_timer.expire = opt * HZ;
1130 break;
1131 case LLC_OPT_BUSY_TMR_EXP:
1132 if (opt > LLC_OPT_MAX_BUSY_TMR_EXP)
1133 goto out;
1134 llc->busy_state_timer.expire = opt * HZ;
1135 break;
1136 case LLC_OPT_TX_WIN:
1137 if (opt > LLC_OPT_MAX_WIN)
1138 goto out;
1139 llc->k = opt;
1140 break;
1141 case LLC_OPT_RX_WIN:
1142 if (opt > LLC_OPT_MAX_WIN)
1143 goto out;
1144 llc->rw = opt;
1145 break;
1146 case LLC_OPT_PKTINFO:
1147 if (opt)
1148 llc->cmsg_flags |= LLC_CMSG_PKTINFO;
1149 else
1150 llc->cmsg_flags &= ~LLC_CMSG_PKTINFO;
1151 break;
1152 default:
1153 rc = -ENOPROTOOPT;
1154 goto out;
1155 }
1156 rc = 0;
1157out:
1158 release_sock(sk);
1159 return rc;
1160}
1161
1162/**
1163 * llc_ui_getsockopt - get connection specific socket info
1164 * @sock: Socket to get information from.
1165 * @level: Socket level user is requesting operations on.
1166 * @optname: Operation name.
1167 * @optval: Variable to return operation data in.
1168 * @optlen: Length of optval.
1169 *
1170 * Get connection specific socket information.
1171 */
1172static int llc_ui_getsockopt(struct socket *sock, int level, int optname,
1173 char __user *optval, int __user *optlen)
1174{
1175 struct sock *sk = sock->sk;
1176 struct llc_sock *llc = llc_sk(sk);
1177 int val = 0, len = 0, rc = -EINVAL;
1178
1179 lock_sock(sk);
1180 if (unlikely(level != SOL_LLC))
1181 goto out;
1182 rc = get_user(len, optlen);
1183 if (rc)
1184 goto out;
1185 rc = -EINVAL;
1186 if (len != sizeof(int))
1187 goto out;
1188 switch (optname) {
1189 case LLC_OPT_RETRY:
1190 val = llc->n2; break;
1191 case LLC_OPT_SIZE:
1192 val = llc->n1; break;
1193 case LLC_OPT_ACK_TMR_EXP:
1194 val = llc->ack_timer.expire / HZ; break;
1195 case LLC_OPT_P_TMR_EXP:
1196 val = llc->pf_cycle_timer.expire / HZ; break;
1197 case LLC_OPT_REJ_TMR_EXP:
1198 val = llc->rej_sent_timer.expire / HZ; break;
1199 case LLC_OPT_BUSY_TMR_EXP:
1200 val = llc->busy_state_timer.expire / HZ; break;
1201 case LLC_OPT_TX_WIN:
1202 val = llc->k; break;
1203 case LLC_OPT_RX_WIN:
1204 val = llc->rw; break;
1205 case LLC_OPT_PKTINFO:
1206 val = (llc->cmsg_flags & LLC_CMSG_PKTINFO) != 0;
1207 break;
1208 default:
1209 rc = -ENOPROTOOPT;
1210 goto out;
1211 }
1212 rc = 0;
1213 if (put_user(len, optlen) || copy_to_user(optval, &val, len))
1214 rc = -EFAULT;
1215out:
1216 release_sock(sk);
1217 return rc;
1218}
1219
1220static const struct net_proto_family llc_ui_family_ops = {
1221 .family = PF_LLC,
1222 .create = llc_ui_create,
1223 .owner = THIS_MODULE,
1224};
1225
1226static const struct proto_ops llc_ui_ops = {
1227 .family = PF_LLC,
1228 .owner = THIS_MODULE,
1229 .release = llc_ui_release,
1230 .bind = llc_ui_bind,
1231 .connect = llc_ui_connect,
1232 .socketpair = sock_no_socketpair,
1233 .accept = llc_ui_accept,
1234 .getname = llc_ui_getname,
1235 .poll = datagram_poll,
1236 .ioctl = llc_ui_ioctl,
1237 .listen = llc_ui_listen,
1238 .shutdown = llc_ui_shutdown,
1239 .setsockopt = llc_ui_setsockopt,
1240 .getsockopt = llc_ui_getsockopt,
1241 .sendmsg = llc_ui_sendmsg,
1242 .recvmsg = llc_ui_recvmsg,
1243 .mmap = sock_no_mmap,
1244};
1245
1246static const char llc_proc_err_msg[] __initconst =
1247 KERN_CRIT "LLC: Unable to register the proc_fs entries\n";
1248static const char llc_sysctl_err_msg[] __initconst =
1249 KERN_CRIT "LLC: Unable to register the sysctl entries\n";
1250static const char llc_sock_err_msg[] __initconst =
1251 KERN_CRIT "LLC: Unable to register the network family\n";
1252
1253static int __init llc2_init(void)
1254{
1255 int rc = proto_register(&llc_proto, 0);
1256
1257 if (rc != 0)
1258 goto out;
1259
1260 llc_build_offset_table();
1261 llc_station_init();
1262 llc_ui_sap_last_autoport = LLC_SAP_DYN_START;
1263 rc = llc_proc_init();
1264 if (rc != 0) {
1265 printk(llc_proc_err_msg);
1266 goto out_station;
1267 }
1268 rc = llc_sysctl_init();
1269 if (rc) {
1270 printk(llc_sysctl_err_msg);
1271 goto out_proc;
1272 }
1273 rc = sock_register(&llc_ui_family_ops);
1274 if (rc) {
1275 printk(llc_sock_err_msg);
1276 goto out_sysctl;
1277 }
1278 llc_add_pack(LLC_DEST_SAP, llc_sap_handler);
1279 llc_add_pack(LLC_DEST_CONN, llc_conn_handler);
1280out:
1281 return rc;
1282out_sysctl:
1283 llc_sysctl_exit();
1284out_proc:
1285 llc_proc_exit();
1286out_station:
1287 llc_station_exit();
1288 proto_unregister(&llc_proto);
1289 goto out;
1290}
1291
1292static void __exit llc2_exit(void)
1293{
1294 llc_station_exit();
1295 llc_remove_pack(LLC_DEST_SAP);
1296 llc_remove_pack(LLC_DEST_CONN);
1297 sock_unregister(PF_LLC);
1298 llc_proc_exit();
1299 llc_sysctl_exit();
1300 proto_unregister(&llc_proto);
1301}
1302
1303module_init(llc2_init);
1304module_exit(llc2_exit);
1305
1306MODULE_LICENSE("GPL");
1307MODULE_AUTHOR("Procom 1997, Jay Schullist 2001, Arnaldo C. Melo 2001-2003");
1308MODULE_DESCRIPTION("IEEE 802.2 PF_LLC support");
1309MODULE_ALIAS_NETPROTO(PF_LLC);