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 */
38 static u16 llc_ui_sap_last_autoport = LLC_SAP_DYN_START;
39 static u16 llc_ui_sap_link_no_max[256];
40 static struct sockaddr_llc llc_ui_addrnull;
41 static const struct proto_ops llc_ui_ops;
42
43 static bool llc_ui_wait_for_conn(struct sock *sk, long timeout);
44 static int llc_ui_wait_for_disc(struct sock *sk, long timeout);
45 static 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 */
63 static 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 */
74 static 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 */
83 static 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 */
97 static 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 */
127 static 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
146 static 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
153 static 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 */
171 static 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 */
200 static 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);
232 out:
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 */
243 static 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;
262 out:
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 */
276 static 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;
321 out:
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 */
340 static 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;
426 out_put:
427 llc_sap_put(sap);
428 out:
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 */
445 static 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);
461 out:
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 */
480 static 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;
536 out:
537 release_sock(sk);
538 return rc;
539 sock_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 */
553 static 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;
576 out:
577 release_sock(sk);
578 return rc;
579 }
580
581 static 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
603 static 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
619 static 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
645 static 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
672 static 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 */
696 static 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);
742 frees:
743 kfree_skb(skb);
744 out:
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 */
759 static 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
901 out:
902 release_sock(sk);
903 return copied;
904 copy_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 */
930 static 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;
1009 out:
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 */
1026 static 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);
1061 out:
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 */
1074 static 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 */
1090 static 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_from_sockptr(&opt, optval, sizeof(opt));
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;
1157 out:
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 */
1172 static 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;
1215 out:
1216 release_sock(sk);
1217 return rc;
1218 }
1219
1220 static const struct net_proto_family llc_ui_family_ops = {
1221 .family = PF_LLC,
1222 .create = llc_ui_create,
1223 .owner = THIS_MODULE,
1224 };
1225
1226 static 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
1246 static const char llc_proc_err_msg[] __initconst =
1247 KERN_CRIT "LLC: Unable to register the proc_fs entries\n";
1248 static const char llc_sysctl_err_msg[] __initconst =
1249 KERN_CRIT "LLC: Unable to register the sysctl entries\n";
1250 static const char llc_sock_err_msg[] __initconst =
1251 KERN_CRIT "LLC: Unable to register the network family\n";
1252
1253 static 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);
1280 out:
1281 return rc;
1282 out_sysctl:
1283 llc_sysctl_exit();
1284 out_proc:
1285 llc_proc_exit();
1286 out_station:
1287 llc_station_exit();
1288 proto_unregister(&llc_proto);
1289 goto out;
1290 }
1291
1292 static 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
1303 module_init(llc2_init);
1304 module_exit(llc2_exit);
1305
1306 MODULE_LICENSE("GPL");
1307 MODULE_AUTHOR("Procom 1997, Jay Schullist 2001, Arnaldo C. Melo 2001-2003");
1308 MODULE_DESCRIPTION("IEEE 802.2 PF_LLC support");
1309 MODULE_ALIAS_NETPROTO(PF_LLC);
1310
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