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1/*
2 * af_llc.c - LLC User Interface SAPs
3 * Description:
4 * Functions in this module are implementation of socket based llc
5 * communications for the Linux operating system. Support of llc class
6 * one and class two is provided via SOCK_DGRAM and SOCK_STREAM
7 * respectively.
8 *
9 * An llc2 connection is (mac + sap), only one llc2 sap connection
10 * is allowed per mac. Though one sap may have multiple mac + sap
11 * connections.
12 *
13 * Copyright (c) 2001 by Jay Schulist <jschlst@samba.org>
14 * 2002-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
15 *
16 * This program can be redistributed or modified under the terms of the
17 * GNU General Public License as published by the Free Software Foundation.
18 * This program is distributed without any warranty or implied warranty
19 * of merchantability or fitness for a particular purpose.
20 *
21 * See the GNU General Public License for more details.
22 */
23#include <linux/compiler.h>
24#include <linux/kernel.h>
25#include <linux/module.h>
26#include <linux/rtnetlink.h>
27#include <linux/init.h>
28#include <linux/slab.h>
29#include <linux/sched/signal.h>
30
31#include <net/llc.h>
32#include <net/llc_sap.h>
33#include <net/llc_pdu.h>
34#include <net/llc_conn.h>
35#include <net/tcp_states.h>
36
37/* remember: uninitialized global data is zeroed because its in .bss */
38static u16 llc_ui_sap_last_autoport = LLC_SAP_DYN_START;
39static u16 llc_ui_sap_link_no_max[256];
40static struct sockaddr_llc llc_ui_addrnull;
41static const struct proto_ops llc_ui_ops;
42
43static bool llc_ui_wait_for_conn(struct sock *sk, long timeout);
44static int llc_ui_wait_for_disc(struct sock *sk, long timeout);
45static int llc_ui_wait_for_busy_core(struct sock *sk, long timeout);
46
47#if 0
48#define dprintk(args...) printk(KERN_DEBUG args)
49#else
50#define dprintk(args...) do {} while (0)
51#endif
52
53/* Maybe we'll add some more in the future. */
54#define LLC_CMSG_PKTINFO 1
55
56
57/**
58 * llc_ui_next_link_no - return the next unused link number for a sap
59 * @sap: Address of sap to get link number from.
60 *
61 * Return the next unused link number for a given sap.
62 */
63static inline u16 llc_ui_next_link_no(int sap)
64{
65 return llc_ui_sap_link_no_max[sap]++;
66}
67
68/**
69 * llc_proto_type - return eth protocol for ARP header type
70 * @arphrd: ARP header type.
71 *
72 * Given an ARP header type return the corresponding ethernet protocol.
73 */
74static inline __be16 llc_proto_type(u16 arphrd)
75{
76 return htons(ETH_P_802_2);
77}
78
79/**
80 * llc_ui_addr_null - determines if a address structure is null
81 * @addr: Address to test if null.
82 */
83static inline u8 llc_ui_addr_null(struct sockaddr_llc *addr)
84{
85 return !memcmp(addr, &llc_ui_addrnull, sizeof(*addr));
86}
87
88/**
89 * llc_ui_header_len - return length of llc header based on operation
90 * @sk: Socket which contains a valid llc socket type.
91 * @addr: Complete sockaddr_llc structure received from the user.
92 *
93 * Provide the length of the llc header depending on what kind of
94 * operation the user would like to perform and the type of socket.
95 * Returns the correct llc header length.
96 */
97static inline u8 llc_ui_header_len(struct sock *sk, struct sockaddr_llc *addr)
98{
99 u8 rc = LLC_PDU_LEN_U;
100
101 if (addr->sllc_test)
102 rc = LLC_PDU_LEN_U;
103 else if (addr->sllc_xid)
104 /* We need to expand header to sizeof(struct llc_xid_info)
105 * since llc_pdu_init_as_xid_cmd() sets 4,5,6 bytes of LLC header
106 * as XID PDU. In llc_ui_sendmsg() we reserved header size and then
107 * filled all other space with user data. If we won't reserve this
108 * bytes, llc_pdu_init_as_xid_cmd() will overwrite user data
109 */
110 rc = LLC_PDU_LEN_U_XID;
111 else if (sk->sk_type == SOCK_STREAM)
112 rc = LLC_PDU_LEN_I;
113 return rc;
114}
115
116/**
117 * llc_ui_send_data - send data via reliable llc2 connection
118 * @sk: Connection the socket is using.
119 * @skb: Data the user wishes to send.
120 * @noblock: can we block waiting for data?
121 *
122 * Send data via reliable llc2 connection.
123 * Returns 0 upon success, non-zero if action did not succeed.
124 *
125 * This function always consumes a reference to the skb.
126 */
127static int llc_ui_send_data(struct sock* sk, struct sk_buff *skb, int noblock)
128{
129 struct llc_sock* llc = llc_sk(sk);
130
131 if (unlikely(llc_data_accept_state(llc->state) ||
132 llc->remote_busy_flag ||
133 llc->p_flag)) {
134 long timeout = sock_sndtimeo(sk, noblock);
135 int rc;
136
137 rc = llc_ui_wait_for_busy_core(sk, timeout);
138 if (rc) {
139 kfree_skb(skb);
140 return rc;
141 }
142 }
143 return llc_build_and_send_pkt(sk, skb);
144}
145
146static void llc_ui_sk_init(struct socket *sock, struct sock *sk)
147{
148 sock_graft(sk, sock);
149 sk->sk_type = sock->type;
150 sock->ops = &llc_ui_ops;
151}
152
153static struct proto llc_proto = {
154 .name = "LLC",
155 .owner = THIS_MODULE,
156 .obj_size = sizeof(struct llc_sock),
157 .slab_flags = SLAB_TYPESAFE_BY_RCU,
158};
159
160/**
161 * llc_ui_create - alloc and init a new llc_ui socket
162 * @net: network namespace (must be default network)
163 * @sock: Socket to initialize and attach allocated sk to.
164 * @protocol: Unused.
165 * @kern: on behalf of kernel or userspace
166 *
167 * Allocate and initialize a new llc_ui socket, validate the user wants a
168 * socket type we have available.
169 * Returns 0 upon success, negative upon failure.
170 */
171static int llc_ui_create(struct net *net, struct socket *sock, int protocol,
172 int kern)
173{
174 struct sock *sk;
175 int rc = -ESOCKTNOSUPPORT;
176
177 if (!ns_capable(net->user_ns, CAP_NET_RAW))
178 return -EPERM;
179
180 if (!net_eq(net, &init_net))
181 return -EAFNOSUPPORT;
182
183 if (likely(sock->type == SOCK_DGRAM || sock->type == SOCK_STREAM)) {
184 rc = -ENOMEM;
185 sk = llc_sk_alloc(net, PF_LLC, GFP_KERNEL, &llc_proto, kern);
186 if (sk) {
187 rc = 0;
188 llc_ui_sk_init(sock, sk);
189 }
190 }
191 return rc;
192}
193
194/**
195 * llc_ui_release - shutdown socket
196 * @sock: Socket to release.
197 *
198 * Shutdown and deallocate an existing socket.
199 */
200static int llc_ui_release(struct socket *sock)
201{
202 struct sock *sk = sock->sk;
203 struct llc_sock *llc;
204
205 if (unlikely(sk == NULL))
206 goto out;
207 sock_hold(sk);
208 lock_sock(sk);
209 llc = llc_sk(sk);
210 dprintk("%s: closing local(%02X) remote(%02X)\n", __func__,
211 llc->laddr.lsap, llc->daddr.lsap);
212 if (!llc_send_disc(sk))
213 llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo);
214 if (!sock_flag(sk, SOCK_ZAPPED)) {
215 struct llc_sap *sap = llc->sap;
216
217 /* Hold this for release_sock(), so that llc_backlog_rcv()
218 * could still use it.
219 */
220 llc_sap_hold(sap);
221 llc_sap_remove_socket(llc->sap, sk);
222 release_sock(sk);
223 llc_sap_put(sap);
224 } else {
225 release_sock(sk);
226 }
227 netdev_put(llc->dev, &llc->dev_tracker);
228 sock_put(sk);
229 llc_sk_free(sk);
230out:
231 return 0;
232}
233
234/**
235 * llc_ui_autoport - provide dynamically allocate SAP number
236 *
237 * Provide the caller with a dynamically allocated SAP number according
238 * to the rules that are set in this function. Returns: 0, upon failure,
239 * SAP number otherwise.
240 */
241static int llc_ui_autoport(void)
242{
243 struct llc_sap *sap;
244 int i, tries = 0;
245
246 while (tries < LLC_SAP_DYN_TRIES) {
247 for (i = llc_ui_sap_last_autoport;
248 i < LLC_SAP_DYN_STOP; i += 2) {
249 sap = llc_sap_find(i);
250 if (!sap) {
251 llc_ui_sap_last_autoport = i + 2;
252 goto out;
253 }
254 llc_sap_put(sap);
255 }
256 llc_ui_sap_last_autoport = LLC_SAP_DYN_START;
257 tries++;
258 }
259 i = 0;
260out:
261 return i;
262}
263
264/**
265 * llc_ui_autobind - automatically bind a socket to a sap
266 * @sock: socket to bind
267 * @addr: address to connect to
268 *
269 * Used by llc_ui_connect and llc_ui_sendmsg when the user hasn't
270 * specifically used llc_ui_bind to bind to an specific address/sap
271 *
272 * Returns: 0 upon success, negative otherwise.
273 */
274static int llc_ui_autobind(struct socket *sock, struct sockaddr_llc *addr)
275{
276 struct sock *sk = sock->sk;
277 struct llc_sock *llc = llc_sk(sk);
278 struct net_device *dev = NULL;
279 struct llc_sap *sap;
280 int rc = -EINVAL;
281
282 if (!sock_flag(sk, SOCK_ZAPPED))
283 goto out;
284 if (!addr->sllc_arphrd)
285 addr->sllc_arphrd = ARPHRD_ETHER;
286 if (addr->sllc_arphrd != ARPHRD_ETHER)
287 goto out;
288 rc = -ENODEV;
289 if (sk->sk_bound_dev_if) {
290 dev = dev_get_by_index(&init_net, sk->sk_bound_dev_if);
291 if (dev && addr->sllc_arphrd != dev->type) {
292 dev_put(dev);
293 dev = NULL;
294 }
295 } else
296 dev = dev_getfirstbyhwtype(&init_net, addr->sllc_arphrd);
297 if (!dev)
298 goto out;
299 rc = -EUSERS;
300 llc->laddr.lsap = llc_ui_autoport();
301 if (!llc->laddr.lsap)
302 goto out;
303 rc = -EBUSY; /* some other network layer is using the sap */
304 sap = llc_sap_open(llc->laddr.lsap, NULL);
305 if (!sap)
306 goto out;
307
308 /* Note: We do not expect errors from this point. */
309 llc->dev = dev;
310 netdev_tracker_alloc(llc->dev, &llc->dev_tracker, GFP_KERNEL);
311 dev = NULL;
312
313 memcpy(llc->laddr.mac, llc->dev->dev_addr, IFHWADDRLEN);
314 memcpy(&llc->addr, addr, sizeof(llc->addr));
315 /* assign new connection to its SAP */
316 llc_sap_add_socket(sap, sk);
317 sock_reset_flag(sk, SOCK_ZAPPED);
318 rc = 0;
319out:
320 dev_put(dev);
321 return rc;
322}
323
324/**
325 * llc_ui_bind - bind a socket to a specific address.
326 * @sock: Socket to bind an address to.
327 * @uaddr: Address the user wants the socket bound to.
328 * @addrlen: Length of the uaddr structure.
329 *
330 * Bind a socket to a specific address. For llc a user is able to bind to
331 * a specific sap only or mac + sap.
332 * If the user desires to bind to a specific mac + sap, it is possible to
333 * have multiple sap connections via multiple macs.
334 * Bind and autobind for that matter must enforce the correct sap usage
335 * otherwise all hell will break loose.
336 * Returns: 0 upon success, negative otherwise.
337 */
338static int llc_ui_bind(struct socket *sock, struct sockaddr *uaddr, int addrlen)
339{
340 struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr;
341 struct sock *sk = sock->sk;
342 struct llc_sock *llc = llc_sk(sk);
343 struct net_device *dev = NULL;
344 struct llc_sap *sap;
345 int rc = -EINVAL;
346
347 lock_sock(sk);
348 if (unlikely(!sock_flag(sk, SOCK_ZAPPED) || addrlen != sizeof(*addr)))
349 goto out;
350 rc = -EAFNOSUPPORT;
351 if (!addr->sllc_arphrd)
352 addr->sllc_arphrd = ARPHRD_ETHER;
353 if (unlikely(addr->sllc_family != AF_LLC || addr->sllc_arphrd != ARPHRD_ETHER))
354 goto out;
355 dprintk("%s: binding %02X\n", __func__, addr->sllc_sap);
356 rc = -ENODEV;
357 rcu_read_lock();
358 if (sk->sk_bound_dev_if) {
359 dev = dev_get_by_index_rcu(&init_net, sk->sk_bound_dev_if);
360 if (dev) {
361 if (is_zero_ether_addr(addr->sllc_mac))
362 memcpy(addr->sllc_mac, dev->dev_addr,
363 IFHWADDRLEN);
364 if (addr->sllc_arphrd != dev->type ||
365 !ether_addr_equal(addr->sllc_mac,
366 dev->dev_addr)) {
367 rc = -EINVAL;
368 dev = NULL;
369 }
370 }
371 } else {
372 dev = dev_getbyhwaddr_rcu(&init_net, addr->sllc_arphrd,
373 addr->sllc_mac);
374 }
375 dev_hold(dev);
376 rcu_read_unlock();
377 if (!dev)
378 goto out;
379
380 if (!addr->sllc_sap) {
381 rc = -EUSERS;
382 addr->sllc_sap = llc_ui_autoport();
383 if (!addr->sllc_sap)
384 goto out;
385 }
386 sap = llc_sap_find(addr->sllc_sap);
387 if (!sap) {
388 sap = llc_sap_open(addr->sllc_sap, NULL);
389 rc = -EBUSY; /* some other network layer is using the sap */
390 if (!sap)
391 goto out;
392 } else {
393 struct llc_addr laddr, daddr;
394 struct sock *ask;
395
396 memset(&laddr, 0, sizeof(laddr));
397 memset(&daddr, 0, sizeof(daddr));
398 /*
399 * FIXME: check if the address is multicast,
400 * only SOCK_DGRAM can do this.
401 */
402 memcpy(laddr.mac, addr->sllc_mac, IFHWADDRLEN);
403 laddr.lsap = addr->sllc_sap;
404 rc = -EADDRINUSE; /* mac + sap clash. */
405 ask = llc_lookup_established(sap, &daddr, &laddr);
406 if (ask) {
407 sock_put(ask);
408 goto out_put;
409 }
410 }
411
412 /* Note: We do not expect errors from this point. */
413 llc->dev = dev;
414 netdev_tracker_alloc(llc->dev, &llc->dev_tracker, GFP_KERNEL);
415 dev = NULL;
416
417 llc->laddr.lsap = addr->sllc_sap;
418 memcpy(llc->laddr.mac, addr->sllc_mac, IFHWADDRLEN);
419 memcpy(&llc->addr, addr, sizeof(llc->addr));
420 /* assign new connection to its SAP */
421 llc_sap_add_socket(sap, sk);
422 sock_reset_flag(sk, SOCK_ZAPPED);
423 rc = 0;
424out_put:
425 llc_sap_put(sap);
426out:
427 dev_put(dev);
428 release_sock(sk);
429 return rc;
430}
431
432/**
433 * llc_ui_shutdown - shutdown a connect llc2 socket.
434 * @sock: Socket to shutdown.
435 * @how: What part of the socket to shutdown.
436 *
437 * Shutdown a connected llc2 socket. Currently this function only supports
438 * shutting down both sends and receives (2), we could probably make this
439 * function such that a user can shutdown only half the connection but not
440 * right now.
441 * Returns: 0 upon success, negative otherwise.
442 */
443static int llc_ui_shutdown(struct socket *sock, int how)
444{
445 struct sock *sk = sock->sk;
446 int rc = -ENOTCONN;
447
448 lock_sock(sk);
449 if (unlikely(sk->sk_state != TCP_ESTABLISHED))
450 goto out;
451 rc = -EINVAL;
452 if (how != 2)
453 goto out;
454 rc = llc_send_disc(sk);
455 if (!rc)
456 rc = llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo);
457 /* Wake up anyone sleeping in poll */
458 sk->sk_state_change(sk);
459out:
460 release_sock(sk);
461 return rc;
462}
463
464/**
465 * llc_ui_connect - Connect to a remote llc2 mac + sap.
466 * @sock: Socket which will be connected to the remote destination.
467 * @uaddr: Remote and possibly the local address of the new connection.
468 * @addrlen: Size of uaddr structure.
469 * @flags: Operational flags specified by the user.
470 *
471 * Connect to a remote llc2 mac + sap. The caller must specify the
472 * destination mac and address to connect to. If the user hasn't previously
473 * called bind(2) with a smac the address of the first interface of the
474 * specified arp type will be used.
475 * This function will autobind if user did not previously call bind.
476 * Returns: 0 upon success, negative otherwise.
477 */
478static int llc_ui_connect(struct socket *sock, struct sockaddr *uaddr,
479 int addrlen, int flags)
480{
481 struct sock *sk = sock->sk;
482 struct llc_sock *llc = llc_sk(sk);
483 struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr;
484 int rc = -EINVAL;
485
486 lock_sock(sk);
487 if (unlikely(addrlen != sizeof(*addr)))
488 goto out;
489 rc = -EAFNOSUPPORT;
490 if (unlikely(addr->sllc_family != AF_LLC))
491 goto out;
492 if (unlikely(sk->sk_type != SOCK_STREAM))
493 goto out;
494 rc = -EALREADY;
495 if (unlikely(sock->state == SS_CONNECTING))
496 goto out;
497 /* bind connection to sap if user hasn't done it. */
498 if (sock_flag(sk, SOCK_ZAPPED)) {
499 /* bind to sap with null dev, exclusive */
500 rc = llc_ui_autobind(sock, addr);
501 if (rc)
502 goto out;
503 }
504 llc->daddr.lsap = addr->sllc_sap;
505 memcpy(llc->daddr.mac, addr->sllc_mac, IFHWADDRLEN);
506 sock->state = SS_CONNECTING;
507 sk->sk_state = TCP_SYN_SENT;
508 llc->link = llc_ui_next_link_no(llc->sap->laddr.lsap);
509 rc = llc_establish_connection(sk, llc->dev->dev_addr,
510 addr->sllc_mac, addr->sllc_sap);
511 if (rc) {
512 dprintk("%s: llc_ui_send_conn failed :-(\n", __func__);
513 sock->state = SS_UNCONNECTED;
514 sk->sk_state = TCP_CLOSE;
515 goto out;
516 }
517
518 if (sk->sk_state == TCP_SYN_SENT) {
519 const long timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
520
521 if (!timeo || !llc_ui_wait_for_conn(sk, timeo))
522 goto out;
523
524 rc = sock_intr_errno(timeo);
525 if (signal_pending(current))
526 goto out;
527 }
528
529 if (sk->sk_state == TCP_CLOSE)
530 goto sock_error;
531
532 sock->state = SS_CONNECTED;
533 rc = 0;
534out:
535 release_sock(sk);
536 return rc;
537sock_error:
538 rc = sock_error(sk) ? : -ECONNABORTED;
539 sock->state = SS_UNCONNECTED;
540 goto out;
541}
542
543/**
544 * llc_ui_listen - allow a normal socket to accept incoming connections
545 * @sock: Socket to allow incoming connections on.
546 * @backlog: Number of connections to queue.
547 *
548 * Allow a normal socket to accept incoming connections.
549 * Returns 0 upon success, negative otherwise.
550 */
551static int llc_ui_listen(struct socket *sock, int backlog)
552{
553 struct sock *sk = sock->sk;
554 int rc = -EINVAL;
555
556 lock_sock(sk);
557 if (unlikely(sock->state != SS_UNCONNECTED))
558 goto out;
559 rc = -EOPNOTSUPP;
560 if (unlikely(sk->sk_type != SOCK_STREAM))
561 goto out;
562 rc = -EAGAIN;
563 if (sock_flag(sk, SOCK_ZAPPED))
564 goto out;
565 rc = 0;
566 if (!(unsigned int)backlog) /* BSDism */
567 backlog = 1;
568 sk->sk_max_ack_backlog = backlog;
569 if (sk->sk_state != TCP_LISTEN) {
570 sk->sk_ack_backlog = 0;
571 sk->sk_state = TCP_LISTEN;
572 }
573 sk->sk_socket->flags |= __SO_ACCEPTCON;
574out:
575 release_sock(sk);
576 return rc;
577}
578
579static int llc_ui_wait_for_disc(struct sock *sk, long timeout)
580{
581 DEFINE_WAIT_FUNC(wait, woken_wake_function);
582 int rc = 0;
583
584 add_wait_queue(sk_sleep(sk), &wait);
585 while (1) {
586 if (sk_wait_event(sk, &timeout, sk->sk_state == TCP_CLOSE, &wait))
587 break;
588 rc = -ERESTARTSYS;
589 if (signal_pending(current))
590 break;
591 rc = -EAGAIN;
592 if (!timeout)
593 break;
594 rc = 0;
595 }
596 remove_wait_queue(sk_sleep(sk), &wait);
597 return rc;
598}
599
600static bool llc_ui_wait_for_conn(struct sock *sk, long timeout)
601{
602 DEFINE_WAIT_FUNC(wait, woken_wake_function);
603
604 add_wait_queue(sk_sleep(sk), &wait);
605 while (1) {
606 if (sk_wait_event(sk, &timeout, sk->sk_state != TCP_SYN_SENT, &wait))
607 break;
608 if (signal_pending(current) || !timeout)
609 break;
610 }
611 remove_wait_queue(sk_sleep(sk), &wait);
612 return timeout;
613}
614
615static int llc_ui_wait_for_busy_core(struct sock *sk, long timeout)
616{
617 DEFINE_WAIT_FUNC(wait, woken_wake_function);
618 struct llc_sock *llc = llc_sk(sk);
619 int rc;
620
621 add_wait_queue(sk_sleep(sk), &wait);
622 while (1) {
623 rc = 0;
624 if (sk_wait_event(sk, &timeout,
625 (sk->sk_shutdown & RCV_SHUTDOWN) ||
626 (!llc_data_accept_state(llc->state) &&
627 !llc->remote_busy_flag &&
628 !llc->p_flag), &wait))
629 break;
630 rc = -ERESTARTSYS;
631 if (signal_pending(current))
632 break;
633 rc = -EAGAIN;
634 if (!timeout)
635 break;
636 }
637 remove_wait_queue(sk_sleep(sk), &wait);
638 return rc;
639}
640
641static int llc_wait_data(struct sock *sk, long timeo)
642{
643 int rc;
644
645 while (1) {
646 /*
647 * POSIX 1003.1g mandates this order.
648 */
649 rc = sock_error(sk);
650 if (rc)
651 break;
652 rc = 0;
653 if (sk->sk_shutdown & RCV_SHUTDOWN)
654 break;
655 rc = -EAGAIN;
656 if (!timeo)
657 break;
658 rc = sock_intr_errno(timeo);
659 if (signal_pending(current))
660 break;
661 rc = 0;
662 if (sk_wait_data(sk, &timeo, NULL))
663 break;
664 }
665 return rc;
666}
667
668static void llc_cmsg_rcv(struct msghdr *msg, struct sk_buff *skb)
669{
670 struct llc_sock *llc = llc_sk(skb->sk);
671
672 if (llc->cmsg_flags & LLC_CMSG_PKTINFO) {
673 struct llc_pktinfo info;
674
675 memset(&info, 0, sizeof(info));
676 info.lpi_ifindex = llc_sk(skb->sk)->dev->ifindex;
677 llc_pdu_decode_dsap(skb, &info.lpi_sap);
678 llc_pdu_decode_da(skb, info.lpi_mac);
679 put_cmsg(msg, SOL_LLC, LLC_OPT_PKTINFO, sizeof(info), &info);
680 }
681}
682
683/**
684 * llc_ui_accept - accept a new incoming connection.
685 * @sock: Socket which connections arrive on.
686 * @newsock: Socket to move incoming connection to.
687 * @flags: User specified operational flags.
688 * @kern: If the socket is kernel internal
689 *
690 * Accept a new incoming connection.
691 * Returns 0 upon success, negative otherwise.
692 */
693static int llc_ui_accept(struct socket *sock, struct socket *newsock, int flags,
694 bool kern)
695{
696 struct sock *sk = sock->sk, *newsk;
697 struct llc_sock *llc, *newllc;
698 struct sk_buff *skb;
699 int rc = -EOPNOTSUPP;
700
701 dprintk("%s: accepting on %02X\n", __func__,
702 llc_sk(sk)->laddr.lsap);
703 lock_sock(sk);
704 if (unlikely(sk->sk_type != SOCK_STREAM))
705 goto out;
706 rc = -EINVAL;
707 if (unlikely(sock->state != SS_UNCONNECTED ||
708 sk->sk_state != TCP_LISTEN))
709 goto out;
710 /* wait for a connection to arrive. */
711 if (skb_queue_empty(&sk->sk_receive_queue)) {
712 rc = llc_wait_data(sk, sk->sk_rcvtimeo);
713 if (rc)
714 goto out;
715 }
716 dprintk("%s: got a new connection on %02X\n", __func__,
717 llc_sk(sk)->laddr.lsap);
718 skb = skb_dequeue(&sk->sk_receive_queue);
719 rc = -EINVAL;
720 if (!skb->sk)
721 goto frees;
722 rc = 0;
723 newsk = skb->sk;
724 /* attach connection to a new socket. */
725 llc_ui_sk_init(newsock, newsk);
726 sock_reset_flag(newsk, SOCK_ZAPPED);
727 newsk->sk_state = TCP_ESTABLISHED;
728 newsock->state = SS_CONNECTED;
729 llc = llc_sk(sk);
730 newllc = llc_sk(newsk);
731 memcpy(&newllc->addr, &llc->addr, sizeof(newllc->addr));
732 newllc->link = llc_ui_next_link_no(newllc->laddr.lsap);
733
734 /* put original socket back into a clean listen state. */
735 sk->sk_state = TCP_LISTEN;
736 sk_acceptq_removed(sk);
737 dprintk("%s: ok success on %02X, client on %02X\n", __func__,
738 llc_sk(sk)->addr.sllc_sap, newllc->daddr.lsap);
739frees:
740 kfree_skb(skb);
741out:
742 release_sock(sk);
743 return rc;
744}
745
746/**
747 * llc_ui_recvmsg - copy received data to the socket user.
748 * @sock: Socket to copy data from.
749 * @msg: Various user space related information.
750 * @len: Size of user buffer.
751 * @flags: User specified flags.
752 *
753 * Copy received data to the socket user.
754 * Returns non-negative upon success, negative otherwise.
755 */
756static int llc_ui_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
757 int flags)
758{
759 DECLARE_SOCKADDR(struct sockaddr_llc *, uaddr, msg->msg_name);
760 const int nonblock = flags & MSG_DONTWAIT;
761 struct sk_buff *skb = NULL;
762 struct sock *sk = sock->sk;
763 struct llc_sock *llc = llc_sk(sk);
764 size_t copied = 0;
765 u32 peek_seq = 0;
766 u32 *seq, skb_len;
767 unsigned long used;
768 int target; /* Read at least this many bytes */
769 long timeo;
770
771 lock_sock(sk);
772 copied = -ENOTCONN;
773 if (unlikely(sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_LISTEN))
774 goto out;
775
776 timeo = sock_rcvtimeo(sk, nonblock);
777
778 seq = &llc->copied_seq;
779 if (flags & MSG_PEEK) {
780 peek_seq = llc->copied_seq;
781 seq = &peek_seq;
782 }
783
784 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
785 copied = 0;
786
787 do {
788 u32 offset;
789
790 /*
791 * We need to check signals first, to get correct SIGURG
792 * handling. FIXME: Need to check this doesn't impact 1003.1g
793 * and move it down to the bottom of the loop
794 */
795 if (signal_pending(current)) {
796 if (copied)
797 break;
798 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN;
799 break;
800 }
801
802 /* Next get a buffer. */
803
804 skb = skb_peek(&sk->sk_receive_queue);
805 if (skb) {
806 offset = *seq;
807 goto found_ok_skb;
808 }
809 /* Well, if we have backlog, try to process it now yet. */
810
811 if (copied >= target && !READ_ONCE(sk->sk_backlog.tail))
812 break;
813
814 if (copied) {
815 if (sk->sk_err ||
816 sk->sk_state == TCP_CLOSE ||
817 (sk->sk_shutdown & RCV_SHUTDOWN) ||
818 !timeo ||
819 (flags & MSG_PEEK))
820 break;
821 } else {
822 if (sock_flag(sk, SOCK_DONE))
823 break;
824
825 if (sk->sk_err) {
826 copied = sock_error(sk);
827 break;
828 }
829 if (sk->sk_shutdown & RCV_SHUTDOWN)
830 break;
831
832 if (sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_CLOSE) {
833 if (!sock_flag(sk, SOCK_DONE)) {
834 /*
835 * This occurs when user tries to read
836 * from never connected socket.
837 */
838 copied = -ENOTCONN;
839 break;
840 }
841 break;
842 }
843 if (!timeo) {
844 copied = -EAGAIN;
845 break;
846 }
847 }
848
849 if (copied >= target) { /* Do not sleep, just process backlog. */
850 release_sock(sk);
851 lock_sock(sk);
852 } else
853 sk_wait_data(sk, &timeo, NULL);
854
855 if ((flags & MSG_PEEK) && peek_seq != llc->copied_seq) {
856 net_dbg_ratelimited("LLC(%s:%d): Application bug, race in MSG_PEEK\n",
857 current->comm,
858 task_pid_nr(current));
859 peek_seq = llc->copied_seq;
860 }
861 continue;
862 found_ok_skb:
863 skb_len = skb->len;
864 /* Ok so how much can we use? */
865 used = skb->len - offset;
866 if (len < used)
867 used = len;
868
869 if (!(flags & MSG_TRUNC)) {
870 int rc = skb_copy_datagram_msg(skb, offset, msg, used);
871 if (rc) {
872 /* Exception. Bailout! */
873 if (!copied)
874 copied = -EFAULT;
875 break;
876 }
877 }
878
879 *seq += used;
880 copied += used;
881 len -= used;
882
883 /* For non stream protcols we get one packet per recvmsg call */
884 if (sk->sk_type != SOCK_STREAM)
885 goto copy_uaddr;
886
887 if (!(flags & MSG_PEEK)) {
888 skb_unlink(skb, &sk->sk_receive_queue);
889 kfree_skb(skb);
890 *seq = 0;
891 }
892
893 /* Partial read */
894 if (used + offset < skb_len)
895 continue;
896 } while (len > 0);
897
898out:
899 release_sock(sk);
900 return copied;
901copy_uaddr:
902 if (uaddr != NULL && skb != NULL) {
903 memcpy(uaddr, llc_ui_skb_cb(skb), sizeof(*uaddr));
904 msg->msg_namelen = sizeof(*uaddr);
905 }
906 if (llc_sk(sk)->cmsg_flags)
907 llc_cmsg_rcv(msg, skb);
908
909 if (!(flags & MSG_PEEK)) {
910 skb_unlink(skb, &sk->sk_receive_queue);
911 kfree_skb(skb);
912 *seq = 0;
913 }
914
915 goto out;
916}
917
918/**
919 * llc_ui_sendmsg - Transmit data provided by the socket user.
920 * @sock: Socket to transmit data from.
921 * @msg: Various user related information.
922 * @len: Length of data to transmit.
923 *
924 * Transmit data provided by the socket user.
925 * Returns non-negative upon success, negative otherwise.
926 */
927static int llc_ui_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
928{
929 struct sock *sk = sock->sk;
930 struct llc_sock *llc = llc_sk(sk);
931 DECLARE_SOCKADDR(struct sockaddr_llc *, addr, msg->msg_name);
932 int flags = msg->msg_flags;
933 int noblock = flags & MSG_DONTWAIT;
934 struct sk_buff *skb = NULL;
935 size_t size = 0;
936 int rc = -EINVAL, copied = 0, hdrlen;
937
938 dprintk("%s: sending from %02X to %02X\n", __func__,
939 llc->laddr.lsap, llc->daddr.lsap);
940 lock_sock(sk);
941 if (addr) {
942 if (msg->msg_namelen < sizeof(*addr))
943 goto out;
944 } else {
945 if (llc_ui_addr_null(&llc->addr))
946 goto out;
947 addr = &llc->addr;
948 }
949 /* must bind connection to sap if user hasn't done it. */
950 if (sock_flag(sk, SOCK_ZAPPED)) {
951 /* bind to sap with null dev, exclusive. */
952 rc = llc_ui_autobind(sock, addr);
953 if (rc)
954 goto out;
955 }
956 hdrlen = llc->dev->hard_header_len + llc_ui_header_len(sk, addr);
957 size = hdrlen + len;
958 if (size > llc->dev->mtu)
959 size = llc->dev->mtu;
960 copied = size - hdrlen;
961 rc = -EINVAL;
962 if (copied < 0)
963 goto out;
964 release_sock(sk);
965 skb = sock_alloc_send_skb(sk, size, noblock, &rc);
966 lock_sock(sk);
967 if (!skb)
968 goto out;
969 skb->dev = llc->dev;
970 skb->protocol = llc_proto_type(addr->sllc_arphrd);
971 skb_reserve(skb, hdrlen);
972 rc = memcpy_from_msg(skb_put(skb, copied), msg, copied);
973 if (rc)
974 goto out;
975 if (sk->sk_type == SOCK_DGRAM || addr->sllc_ua) {
976 llc_build_and_send_ui_pkt(llc->sap, skb, addr->sllc_mac,
977 addr->sllc_sap);
978 skb = NULL;
979 goto out;
980 }
981 if (addr->sllc_test) {
982 llc_build_and_send_test_pkt(llc->sap, skb, addr->sllc_mac,
983 addr->sllc_sap);
984 skb = NULL;
985 goto out;
986 }
987 if (addr->sllc_xid) {
988 llc_build_and_send_xid_pkt(llc->sap, skb, addr->sllc_mac,
989 addr->sllc_sap);
990 skb = NULL;
991 goto out;
992 }
993 rc = -ENOPROTOOPT;
994 if (!(sk->sk_type == SOCK_STREAM && !addr->sllc_ua))
995 goto out;
996 rc = llc_ui_send_data(sk, skb, noblock);
997 skb = NULL;
998out:
999 kfree_skb(skb);
1000 if (rc)
1001 dprintk("%s: failed sending from %02X to %02X: %d\n",
1002 __func__, llc->laddr.lsap, llc->daddr.lsap, rc);
1003 release_sock(sk);
1004 return rc ? : copied;
1005}
1006
1007/**
1008 * llc_ui_getname - return the address info of a socket
1009 * @sock: Socket to get address of.
1010 * @uaddr: Address structure to return information.
1011 * @peer: Does user want local or remote address information.
1012 *
1013 * Return the address information of a socket.
1014 */
1015static int llc_ui_getname(struct socket *sock, struct sockaddr *uaddr,
1016 int peer)
1017{
1018 struct sockaddr_llc sllc;
1019 struct sock *sk = sock->sk;
1020 struct llc_sock *llc = llc_sk(sk);
1021 int rc = -EBADF;
1022
1023 memset(&sllc, 0, sizeof(sllc));
1024 lock_sock(sk);
1025 if (sock_flag(sk, SOCK_ZAPPED))
1026 goto out;
1027 if (peer) {
1028 rc = -ENOTCONN;
1029 if (sk->sk_state != TCP_ESTABLISHED)
1030 goto out;
1031 if(llc->dev)
1032 sllc.sllc_arphrd = llc->dev->type;
1033 sllc.sllc_sap = llc->daddr.lsap;
1034 memcpy(&sllc.sllc_mac, &llc->daddr.mac, IFHWADDRLEN);
1035 } else {
1036 rc = -EINVAL;
1037 if (!llc->sap)
1038 goto out;
1039 sllc.sllc_sap = llc->sap->laddr.lsap;
1040
1041 if (llc->dev) {
1042 sllc.sllc_arphrd = llc->dev->type;
1043 memcpy(&sllc.sllc_mac, llc->dev->dev_addr,
1044 IFHWADDRLEN);
1045 }
1046 }
1047 sllc.sllc_family = AF_LLC;
1048 memcpy(uaddr, &sllc, sizeof(sllc));
1049 rc = sizeof(sllc);
1050out:
1051 release_sock(sk);
1052 return rc;
1053}
1054
1055/**
1056 * llc_ui_ioctl - io controls for PF_LLC
1057 * @sock: Socket to get/set info
1058 * @cmd: command
1059 * @arg: optional argument for cmd
1060 *
1061 * get/set info on llc sockets
1062 */
1063static int llc_ui_ioctl(struct socket *sock, unsigned int cmd,
1064 unsigned long arg)
1065{
1066 return -ENOIOCTLCMD;
1067}
1068
1069/**
1070 * llc_ui_setsockopt - set various connection specific parameters.
1071 * @sock: Socket to set options on.
1072 * @level: Socket level user is requesting operations on.
1073 * @optname: Operation name.
1074 * @optval: User provided operation data.
1075 * @optlen: Length of optval.
1076 *
1077 * Set various connection specific parameters.
1078 */
1079static int llc_ui_setsockopt(struct socket *sock, int level, int optname,
1080 sockptr_t optval, unsigned int optlen)
1081{
1082 struct sock *sk = sock->sk;
1083 struct llc_sock *llc = llc_sk(sk);
1084 unsigned int opt;
1085 int rc = -EINVAL;
1086
1087 lock_sock(sk);
1088 if (unlikely(level != SOL_LLC || optlen != sizeof(int)))
1089 goto out;
1090 rc = copy_from_sockptr(&opt, optval, sizeof(opt));
1091 if (rc)
1092 goto out;
1093 rc = -EINVAL;
1094 switch (optname) {
1095 case LLC_OPT_RETRY:
1096 if (opt > LLC_OPT_MAX_RETRY)
1097 goto out;
1098 llc->n2 = opt;
1099 break;
1100 case LLC_OPT_SIZE:
1101 if (opt > LLC_OPT_MAX_SIZE)
1102 goto out;
1103 llc->n1 = opt;
1104 break;
1105 case LLC_OPT_ACK_TMR_EXP:
1106 if (opt > LLC_OPT_MAX_ACK_TMR_EXP)
1107 goto out;
1108 llc->ack_timer.expire = opt * HZ;
1109 break;
1110 case LLC_OPT_P_TMR_EXP:
1111 if (opt > LLC_OPT_MAX_P_TMR_EXP)
1112 goto out;
1113 llc->pf_cycle_timer.expire = opt * HZ;
1114 break;
1115 case LLC_OPT_REJ_TMR_EXP:
1116 if (opt > LLC_OPT_MAX_REJ_TMR_EXP)
1117 goto out;
1118 llc->rej_sent_timer.expire = opt * HZ;
1119 break;
1120 case LLC_OPT_BUSY_TMR_EXP:
1121 if (opt > LLC_OPT_MAX_BUSY_TMR_EXP)
1122 goto out;
1123 llc->busy_state_timer.expire = opt * HZ;
1124 break;
1125 case LLC_OPT_TX_WIN:
1126 if (opt > LLC_OPT_MAX_WIN)
1127 goto out;
1128 llc->k = opt;
1129 break;
1130 case LLC_OPT_RX_WIN:
1131 if (opt > LLC_OPT_MAX_WIN)
1132 goto out;
1133 llc->rw = opt;
1134 break;
1135 case LLC_OPT_PKTINFO:
1136 if (opt)
1137 llc->cmsg_flags |= LLC_CMSG_PKTINFO;
1138 else
1139 llc->cmsg_flags &= ~LLC_CMSG_PKTINFO;
1140 break;
1141 default:
1142 rc = -ENOPROTOOPT;
1143 goto out;
1144 }
1145 rc = 0;
1146out:
1147 release_sock(sk);
1148 return rc;
1149}
1150
1151/**
1152 * llc_ui_getsockopt - get connection specific socket info
1153 * @sock: Socket to get information from.
1154 * @level: Socket level user is requesting operations on.
1155 * @optname: Operation name.
1156 * @optval: Variable to return operation data in.
1157 * @optlen: Length of optval.
1158 *
1159 * Get connection specific socket information.
1160 */
1161static int llc_ui_getsockopt(struct socket *sock, int level, int optname,
1162 char __user *optval, int __user *optlen)
1163{
1164 struct sock *sk = sock->sk;
1165 struct llc_sock *llc = llc_sk(sk);
1166 int val = 0, len = 0, rc = -EINVAL;
1167
1168 lock_sock(sk);
1169 if (unlikely(level != SOL_LLC))
1170 goto out;
1171 rc = get_user(len, optlen);
1172 if (rc)
1173 goto out;
1174 rc = -EINVAL;
1175 if (len != sizeof(int))
1176 goto out;
1177 switch (optname) {
1178 case LLC_OPT_RETRY:
1179 val = llc->n2; break;
1180 case LLC_OPT_SIZE:
1181 val = llc->n1; break;
1182 case LLC_OPT_ACK_TMR_EXP:
1183 val = llc->ack_timer.expire / HZ; break;
1184 case LLC_OPT_P_TMR_EXP:
1185 val = llc->pf_cycle_timer.expire / HZ; break;
1186 case LLC_OPT_REJ_TMR_EXP:
1187 val = llc->rej_sent_timer.expire / HZ; break;
1188 case LLC_OPT_BUSY_TMR_EXP:
1189 val = llc->busy_state_timer.expire / HZ; break;
1190 case LLC_OPT_TX_WIN:
1191 val = llc->k; break;
1192 case LLC_OPT_RX_WIN:
1193 val = llc->rw; break;
1194 case LLC_OPT_PKTINFO:
1195 val = (llc->cmsg_flags & LLC_CMSG_PKTINFO) != 0;
1196 break;
1197 default:
1198 rc = -ENOPROTOOPT;
1199 goto out;
1200 }
1201 rc = 0;
1202 if (put_user(len, optlen) || copy_to_user(optval, &val, len))
1203 rc = -EFAULT;
1204out:
1205 release_sock(sk);
1206 return rc;
1207}
1208
1209static const struct net_proto_family llc_ui_family_ops = {
1210 .family = PF_LLC,
1211 .create = llc_ui_create,
1212 .owner = THIS_MODULE,
1213};
1214
1215static const struct proto_ops llc_ui_ops = {
1216 .family = PF_LLC,
1217 .owner = THIS_MODULE,
1218 .release = llc_ui_release,
1219 .bind = llc_ui_bind,
1220 .connect = llc_ui_connect,
1221 .socketpair = sock_no_socketpair,
1222 .accept = llc_ui_accept,
1223 .getname = llc_ui_getname,
1224 .poll = datagram_poll,
1225 .ioctl = llc_ui_ioctl,
1226 .listen = llc_ui_listen,
1227 .shutdown = llc_ui_shutdown,
1228 .setsockopt = llc_ui_setsockopt,
1229 .getsockopt = llc_ui_getsockopt,
1230 .sendmsg = llc_ui_sendmsg,
1231 .recvmsg = llc_ui_recvmsg,
1232 .mmap = sock_no_mmap,
1233 .sendpage = sock_no_sendpage,
1234};
1235
1236static const char llc_proc_err_msg[] __initconst =
1237 KERN_CRIT "LLC: Unable to register the proc_fs entries\n";
1238static const char llc_sysctl_err_msg[] __initconst =
1239 KERN_CRIT "LLC: Unable to register the sysctl entries\n";
1240static const char llc_sock_err_msg[] __initconst =
1241 KERN_CRIT "LLC: Unable to register the network family\n";
1242
1243static int __init llc2_init(void)
1244{
1245 int rc = proto_register(&llc_proto, 0);
1246
1247 if (rc != 0)
1248 goto out;
1249
1250 llc_build_offset_table();
1251 llc_station_init();
1252 llc_ui_sap_last_autoport = LLC_SAP_DYN_START;
1253 rc = llc_proc_init();
1254 if (rc != 0) {
1255 printk(llc_proc_err_msg);
1256 goto out_station;
1257 }
1258 rc = llc_sysctl_init();
1259 if (rc) {
1260 printk(llc_sysctl_err_msg);
1261 goto out_proc;
1262 }
1263 rc = sock_register(&llc_ui_family_ops);
1264 if (rc) {
1265 printk(llc_sock_err_msg);
1266 goto out_sysctl;
1267 }
1268 llc_add_pack(LLC_DEST_SAP, llc_sap_handler);
1269 llc_add_pack(LLC_DEST_CONN, llc_conn_handler);
1270out:
1271 return rc;
1272out_sysctl:
1273 llc_sysctl_exit();
1274out_proc:
1275 llc_proc_exit();
1276out_station:
1277 llc_station_exit();
1278 proto_unregister(&llc_proto);
1279 goto out;
1280}
1281
1282static void __exit llc2_exit(void)
1283{
1284 llc_station_exit();
1285 llc_remove_pack(LLC_DEST_SAP);
1286 llc_remove_pack(LLC_DEST_CONN);
1287 sock_unregister(PF_LLC);
1288 llc_proc_exit();
1289 llc_sysctl_exit();
1290 proto_unregister(&llc_proto);
1291}
1292
1293module_init(llc2_init);
1294module_exit(llc2_exit);
1295
1296MODULE_LICENSE("GPL");
1297MODULE_AUTHOR("Procom 1997, Jay Schullist 2001, Arnaldo C. Melo 2001-2003");
1298MODULE_DESCRIPTION("IEEE 802.2 PF_LLC support");
1299MODULE_ALIAS_NETPROTO(PF_LLC);
1/*
2 * af_llc.c - LLC User Interface SAPs
3 * Description:
4 * Functions in this module are implementation of socket based llc
5 * communications for the Linux operating system. Support of llc class
6 * one and class two is provided via SOCK_DGRAM and SOCK_STREAM
7 * respectively.
8 *
9 * An llc2 connection is (mac + sap), only one llc2 sap connection
10 * is allowed per mac. Though one sap may have multiple mac + sap
11 * connections.
12 *
13 * Copyright (c) 2001 by Jay Schulist <jschlst@samba.org>
14 * 2002-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
15 *
16 * This program can be redistributed or modified under the terms of the
17 * GNU General Public License as published by the Free Software Foundation.
18 * This program is distributed without any warranty or implied warranty
19 * of merchantability or fitness for a particular purpose.
20 *
21 * See the GNU General Public License for more details.
22 */
23#include <linux/compiler.h>
24#include <linux/kernel.h>
25#include <linux/module.h>
26#include <linux/rtnetlink.h>
27#include <linux/init.h>
28#include <linux/slab.h>
29#include <linux/sched/signal.h>
30
31#include <net/llc.h>
32#include <net/llc_sap.h>
33#include <net/llc_pdu.h>
34#include <net/llc_conn.h>
35#include <net/tcp_states.h>
36
37/* remember: uninitialized global data is zeroed because its in .bss */
38static u16 llc_ui_sap_last_autoport = LLC_SAP_DYN_START;
39static u16 llc_ui_sap_link_no_max[256];
40static struct sockaddr_llc llc_ui_addrnull;
41static const struct proto_ops llc_ui_ops;
42
43static bool llc_ui_wait_for_conn(struct sock *sk, long timeout);
44static int llc_ui_wait_for_disc(struct sock *sk, long timeout);
45static int llc_ui_wait_for_busy_core(struct sock *sk, long timeout);
46
47#if 0
48#define dprintk(args...) printk(KERN_DEBUG args)
49#else
50#define dprintk(args...)
51#endif
52
53/* Maybe we'll add some more in the future. */
54#define LLC_CMSG_PKTINFO 1
55
56
57/**
58 * llc_ui_next_link_no - return the next unused link number for a sap
59 * @sap: Address of sap to get link number from.
60 *
61 * Return the next unused link number for a given sap.
62 */
63static inline u16 llc_ui_next_link_no(int sap)
64{
65 return llc_ui_sap_link_no_max[sap]++;
66}
67
68/**
69 * llc_proto_type - return eth protocol for ARP header type
70 * @arphrd: ARP header type.
71 *
72 * Given an ARP header type return the corresponding ethernet protocol.
73 */
74static inline __be16 llc_proto_type(u16 arphrd)
75{
76 return htons(ETH_P_802_2);
77}
78
79/**
80 * llc_ui_addr_null - determines if a address structure is null
81 * @addr: Address to test if null.
82 */
83static inline u8 llc_ui_addr_null(struct sockaddr_llc *addr)
84{
85 return !memcmp(addr, &llc_ui_addrnull, sizeof(*addr));
86}
87
88/**
89 * llc_ui_header_len - return length of llc header based on operation
90 * @sk: Socket which contains a valid llc socket type.
91 * @addr: Complete sockaddr_llc structure received from the user.
92 *
93 * Provide the length of the llc header depending on what kind of
94 * operation the user would like to perform and the type of socket.
95 * Returns the correct llc header length.
96 */
97static inline u8 llc_ui_header_len(struct sock *sk, struct sockaddr_llc *addr)
98{
99 u8 rc = LLC_PDU_LEN_U;
100
101 if (addr->sllc_test || addr->sllc_xid)
102 rc = LLC_PDU_LEN_U;
103 else if (sk->sk_type == SOCK_STREAM)
104 rc = LLC_PDU_LEN_I;
105 return rc;
106}
107
108/**
109 * llc_ui_send_data - send data via reliable llc2 connection
110 * @sk: Connection the socket is using.
111 * @skb: Data the user wishes to send.
112 * @noblock: can we block waiting for data?
113 *
114 * Send data via reliable llc2 connection.
115 * Returns 0 upon success, non-zero if action did not succeed.
116 */
117static int llc_ui_send_data(struct sock* sk, struct sk_buff *skb, int noblock)
118{
119 struct llc_sock* llc = llc_sk(sk);
120 int rc = 0;
121
122 if (unlikely(llc_data_accept_state(llc->state) ||
123 llc->remote_busy_flag ||
124 llc->p_flag)) {
125 long timeout = sock_sndtimeo(sk, noblock);
126
127 rc = llc_ui_wait_for_busy_core(sk, timeout);
128 }
129 if (unlikely(!rc))
130 rc = llc_build_and_send_pkt(sk, skb);
131 return rc;
132}
133
134static void llc_ui_sk_init(struct socket *sock, struct sock *sk)
135{
136 sock_graft(sk, sock);
137 sk->sk_type = sock->type;
138 sock->ops = &llc_ui_ops;
139}
140
141static struct proto llc_proto = {
142 .name = "LLC",
143 .owner = THIS_MODULE,
144 .obj_size = sizeof(struct llc_sock),
145 .slab_flags = SLAB_TYPESAFE_BY_RCU,
146};
147
148/**
149 * llc_ui_create - alloc and init a new llc_ui socket
150 * @net: network namespace (must be default network)
151 * @sock: Socket to initialize and attach allocated sk to.
152 * @protocol: Unused.
153 * @kern: on behalf of kernel or userspace
154 *
155 * Allocate and initialize a new llc_ui socket, validate the user wants a
156 * socket type we have available.
157 * Returns 0 upon success, negative upon failure.
158 */
159static int llc_ui_create(struct net *net, struct socket *sock, int protocol,
160 int kern)
161{
162 struct sock *sk;
163 int rc = -ESOCKTNOSUPPORT;
164
165 if (!ns_capable(net->user_ns, CAP_NET_RAW))
166 return -EPERM;
167
168 if (!net_eq(net, &init_net))
169 return -EAFNOSUPPORT;
170
171 if (likely(sock->type == SOCK_DGRAM || sock->type == SOCK_STREAM)) {
172 rc = -ENOMEM;
173 sk = llc_sk_alloc(net, PF_LLC, GFP_KERNEL, &llc_proto, kern);
174 if (sk) {
175 rc = 0;
176 llc_ui_sk_init(sock, sk);
177 }
178 }
179 return rc;
180}
181
182/**
183 * llc_ui_release - shutdown socket
184 * @sock: Socket to release.
185 *
186 * Shutdown and deallocate an existing socket.
187 */
188static int llc_ui_release(struct socket *sock)
189{
190 struct sock *sk = sock->sk;
191 struct llc_sock *llc;
192
193 if (unlikely(sk == NULL))
194 goto out;
195 sock_hold(sk);
196 lock_sock(sk);
197 llc = llc_sk(sk);
198 dprintk("%s: closing local(%02X) remote(%02X)\n", __func__,
199 llc->laddr.lsap, llc->daddr.lsap);
200 if (!llc_send_disc(sk))
201 llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo);
202 if (!sock_flag(sk, SOCK_ZAPPED)) {
203 struct llc_sap *sap = llc->sap;
204
205 /* Hold this for release_sock(), so that llc_backlog_rcv()
206 * could still use it.
207 */
208 llc_sap_hold(sap);
209 llc_sap_remove_socket(llc->sap, sk);
210 release_sock(sk);
211 llc_sap_put(sap);
212 } else {
213 release_sock(sk);
214 }
215 if (llc->dev)
216 dev_put(llc->dev);
217 sock_put(sk);
218 llc_sk_free(sk);
219out:
220 return 0;
221}
222
223/**
224 * llc_ui_autoport - provide dynamically allocate SAP number
225 *
226 * Provide the caller with a dynamically allocated SAP number according
227 * to the rules that are set in this function. Returns: 0, upon failure,
228 * SAP number otherwise.
229 */
230static int llc_ui_autoport(void)
231{
232 struct llc_sap *sap;
233 int i, tries = 0;
234
235 while (tries < LLC_SAP_DYN_TRIES) {
236 for (i = llc_ui_sap_last_autoport;
237 i < LLC_SAP_DYN_STOP; i += 2) {
238 sap = llc_sap_find(i);
239 if (!sap) {
240 llc_ui_sap_last_autoport = i + 2;
241 goto out;
242 }
243 llc_sap_put(sap);
244 }
245 llc_ui_sap_last_autoport = LLC_SAP_DYN_START;
246 tries++;
247 }
248 i = 0;
249out:
250 return i;
251}
252
253/**
254 * llc_ui_autobind - automatically bind a socket to a sap
255 * @sock: socket to bind
256 * @addr: address to connect to
257 *
258 * Used by llc_ui_connect and llc_ui_sendmsg when the user hasn't
259 * specifically used llc_ui_bind to bind to an specific address/sap
260 *
261 * Returns: 0 upon success, negative otherwise.
262 */
263static int llc_ui_autobind(struct socket *sock, struct sockaddr_llc *addr)
264{
265 struct sock *sk = sock->sk;
266 struct llc_sock *llc = llc_sk(sk);
267 struct llc_sap *sap;
268 int rc = -EINVAL;
269
270 if (!sock_flag(sk, SOCK_ZAPPED))
271 goto out;
272 rc = -ENODEV;
273 if (sk->sk_bound_dev_if) {
274 llc->dev = dev_get_by_index(&init_net, sk->sk_bound_dev_if);
275 if (llc->dev && addr->sllc_arphrd != llc->dev->type) {
276 dev_put(llc->dev);
277 llc->dev = NULL;
278 }
279 } else
280 llc->dev = dev_getfirstbyhwtype(&init_net, addr->sllc_arphrd);
281 if (!llc->dev)
282 goto out;
283 rc = -EUSERS;
284 llc->laddr.lsap = llc_ui_autoport();
285 if (!llc->laddr.lsap)
286 goto out;
287 rc = -EBUSY; /* some other network layer is using the sap */
288 sap = llc_sap_open(llc->laddr.lsap, NULL);
289 if (!sap)
290 goto out;
291 memcpy(llc->laddr.mac, llc->dev->dev_addr, IFHWADDRLEN);
292 memcpy(&llc->addr, addr, sizeof(llc->addr));
293 /* assign new connection to its SAP */
294 llc_sap_add_socket(sap, sk);
295 sock_reset_flag(sk, SOCK_ZAPPED);
296 rc = 0;
297out:
298 return rc;
299}
300
301/**
302 * llc_ui_bind - bind a socket to a specific address.
303 * @sock: Socket to bind an address to.
304 * @uaddr: Address the user wants the socket bound to.
305 * @addrlen: Length of the uaddr structure.
306 *
307 * Bind a socket to a specific address. For llc a user is able to bind to
308 * a specific sap only or mac + sap.
309 * If the user desires to bind to a specific mac + sap, it is possible to
310 * have multiple sap connections via multiple macs.
311 * Bind and autobind for that matter must enforce the correct sap usage
312 * otherwise all hell will break loose.
313 * Returns: 0 upon success, negative otherwise.
314 */
315static int llc_ui_bind(struct socket *sock, struct sockaddr *uaddr, int addrlen)
316{
317 struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr;
318 struct sock *sk = sock->sk;
319 struct llc_sock *llc = llc_sk(sk);
320 struct llc_sap *sap;
321 int rc = -EINVAL;
322
323 dprintk("%s: binding %02X\n", __func__, addr->sllc_sap);
324
325 lock_sock(sk);
326 if (unlikely(!sock_flag(sk, SOCK_ZAPPED) || addrlen != sizeof(*addr)))
327 goto out;
328 rc = -EAFNOSUPPORT;
329 if (unlikely(addr->sllc_family != AF_LLC))
330 goto out;
331 rc = -ENODEV;
332 rcu_read_lock();
333 if (sk->sk_bound_dev_if) {
334 llc->dev = dev_get_by_index_rcu(&init_net, sk->sk_bound_dev_if);
335 if (llc->dev) {
336 if (!addr->sllc_arphrd)
337 addr->sllc_arphrd = llc->dev->type;
338 if (is_zero_ether_addr(addr->sllc_mac))
339 memcpy(addr->sllc_mac, llc->dev->dev_addr,
340 IFHWADDRLEN);
341 if (addr->sllc_arphrd != llc->dev->type ||
342 !ether_addr_equal(addr->sllc_mac,
343 llc->dev->dev_addr)) {
344 rc = -EINVAL;
345 llc->dev = NULL;
346 }
347 }
348 } else
349 llc->dev = dev_getbyhwaddr_rcu(&init_net, addr->sllc_arphrd,
350 addr->sllc_mac);
351 if (llc->dev)
352 dev_hold(llc->dev);
353 rcu_read_unlock();
354 if (!llc->dev)
355 goto out;
356 if (!addr->sllc_sap) {
357 rc = -EUSERS;
358 addr->sllc_sap = llc_ui_autoport();
359 if (!addr->sllc_sap)
360 goto out;
361 }
362 sap = llc_sap_find(addr->sllc_sap);
363 if (!sap) {
364 sap = llc_sap_open(addr->sllc_sap, NULL);
365 rc = -EBUSY; /* some other network layer is using the sap */
366 if (!sap)
367 goto out;
368 } else {
369 struct llc_addr laddr, daddr;
370 struct sock *ask;
371
372 memset(&laddr, 0, sizeof(laddr));
373 memset(&daddr, 0, sizeof(daddr));
374 /*
375 * FIXME: check if the address is multicast,
376 * only SOCK_DGRAM can do this.
377 */
378 memcpy(laddr.mac, addr->sllc_mac, IFHWADDRLEN);
379 laddr.lsap = addr->sllc_sap;
380 rc = -EADDRINUSE; /* mac + sap clash. */
381 ask = llc_lookup_established(sap, &daddr, &laddr);
382 if (ask) {
383 sock_put(ask);
384 goto out_put;
385 }
386 }
387 llc->laddr.lsap = addr->sllc_sap;
388 memcpy(llc->laddr.mac, addr->sllc_mac, IFHWADDRLEN);
389 memcpy(&llc->addr, addr, sizeof(llc->addr));
390 /* assign new connection to its SAP */
391 llc_sap_add_socket(sap, sk);
392 sock_reset_flag(sk, SOCK_ZAPPED);
393 rc = 0;
394out_put:
395 llc_sap_put(sap);
396out:
397 release_sock(sk);
398 return rc;
399}
400
401/**
402 * llc_ui_shutdown - shutdown a connect llc2 socket.
403 * @sock: Socket to shutdown.
404 * @how: What part of the socket to shutdown.
405 *
406 * Shutdown a connected llc2 socket. Currently this function only supports
407 * shutting down both sends and receives (2), we could probably make this
408 * function such that a user can shutdown only half the connection but not
409 * right now.
410 * Returns: 0 upon success, negative otherwise.
411 */
412static int llc_ui_shutdown(struct socket *sock, int how)
413{
414 struct sock *sk = sock->sk;
415 int rc = -ENOTCONN;
416
417 lock_sock(sk);
418 if (unlikely(sk->sk_state != TCP_ESTABLISHED))
419 goto out;
420 rc = -EINVAL;
421 if (how != 2)
422 goto out;
423 rc = llc_send_disc(sk);
424 if (!rc)
425 rc = llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo);
426 /* Wake up anyone sleeping in poll */
427 sk->sk_state_change(sk);
428out:
429 release_sock(sk);
430 return rc;
431}
432
433/**
434 * llc_ui_connect - Connect to a remote llc2 mac + sap.
435 * @sock: Socket which will be connected to the remote destination.
436 * @uaddr: Remote and possibly the local address of the new connection.
437 * @addrlen: Size of uaddr structure.
438 * @flags: Operational flags specified by the user.
439 *
440 * Connect to a remote llc2 mac + sap. The caller must specify the
441 * destination mac and address to connect to. If the user hasn't previously
442 * called bind(2) with a smac the address of the first interface of the
443 * specified arp type will be used.
444 * This function will autobind if user did not previously call bind.
445 * Returns: 0 upon success, negative otherwise.
446 */
447static int llc_ui_connect(struct socket *sock, struct sockaddr *uaddr,
448 int addrlen, int flags)
449{
450 struct sock *sk = sock->sk;
451 struct llc_sock *llc = llc_sk(sk);
452 struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr;
453 int rc = -EINVAL;
454
455 lock_sock(sk);
456 if (unlikely(addrlen != sizeof(*addr)))
457 goto out;
458 rc = -EAFNOSUPPORT;
459 if (unlikely(addr->sllc_family != AF_LLC))
460 goto out;
461 if (unlikely(sk->sk_type != SOCK_STREAM))
462 goto out;
463 rc = -EALREADY;
464 if (unlikely(sock->state == SS_CONNECTING))
465 goto out;
466 /* bind connection to sap if user hasn't done it. */
467 if (sock_flag(sk, SOCK_ZAPPED)) {
468 /* bind to sap with null dev, exclusive */
469 rc = llc_ui_autobind(sock, addr);
470 if (rc)
471 goto out;
472 }
473 llc->daddr.lsap = addr->sllc_sap;
474 memcpy(llc->daddr.mac, addr->sllc_mac, IFHWADDRLEN);
475 sock->state = SS_CONNECTING;
476 sk->sk_state = TCP_SYN_SENT;
477 llc->link = llc_ui_next_link_no(llc->sap->laddr.lsap);
478 rc = llc_establish_connection(sk, llc->dev->dev_addr,
479 addr->sllc_mac, addr->sllc_sap);
480 if (rc) {
481 dprintk("%s: llc_ui_send_conn failed :-(\n", __func__);
482 sock->state = SS_UNCONNECTED;
483 sk->sk_state = TCP_CLOSE;
484 goto out;
485 }
486
487 if (sk->sk_state == TCP_SYN_SENT) {
488 const long timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
489
490 if (!timeo || !llc_ui_wait_for_conn(sk, timeo))
491 goto out;
492
493 rc = sock_intr_errno(timeo);
494 if (signal_pending(current))
495 goto out;
496 }
497
498 if (sk->sk_state == TCP_CLOSE)
499 goto sock_error;
500
501 sock->state = SS_CONNECTED;
502 rc = 0;
503out:
504 release_sock(sk);
505 return rc;
506sock_error:
507 rc = sock_error(sk) ? : -ECONNABORTED;
508 sock->state = SS_UNCONNECTED;
509 goto out;
510}
511
512/**
513 * llc_ui_listen - allow a normal socket to accept incoming connections
514 * @sock: Socket to allow incoming connections on.
515 * @backlog: Number of connections to queue.
516 *
517 * Allow a normal socket to accept incoming connections.
518 * Returns 0 upon success, negative otherwise.
519 */
520static int llc_ui_listen(struct socket *sock, int backlog)
521{
522 struct sock *sk = sock->sk;
523 int rc = -EINVAL;
524
525 lock_sock(sk);
526 if (unlikely(sock->state != SS_UNCONNECTED))
527 goto out;
528 rc = -EOPNOTSUPP;
529 if (unlikely(sk->sk_type != SOCK_STREAM))
530 goto out;
531 rc = -EAGAIN;
532 if (sock_flag(sk, SOCK_ZAPPED))
533 goto out;
534 rc = 0;
535 if (!(unsigned int)backlog) /* BSDism */
536 backlog = 1;
537 sk->sk_max_ack_backlog = backlog;
538 if (sk->sk_state != TCP_LISTEN) {
539 sk->sk_ack_backlog = 0;
540 sk->sk_state = TCP_LISTEN;
541 }
542 sk->sk_socket->flags |= __SO_ACCEPTCON;
543out:
544 release_sock(sk);
545 return rc;
546}
547
548static int llc_ui_wait_for_disc(struct sock *sk, long timeout)
549{
550 DEFINE_WAIT_FUNC(wait, woken_wake_function);
551 int rc = 0;
552
553 add_wait_queue(sk_sleep(sk), &wait);
554 while (1) {
555 if (sk_wait_event(sk, &timeout, sk->sk_state == TCP_CLOSE, &wait))
556 break;
557 rc = -ERESTARTSYS;
558 if (signal_pending(current))
559 break;
560 rc = -EAGAIN;
561 if (!timeout)
562 break;
563 rc = 0;
564 }
565 remove_wait_queue(sk_sleep(sk), &wait);
566 return rc;
567}
568
569static bool llc_ui_wait_for_conn(struct sock *sk, long timeout)
570{
571 DEFINE_WAIT_FUNC(wait, woken_wake_function);
572
573 add_wait_queue(sk_sleep(sk), &wait);
574 while (1) {
575 if (sk_wait_event(sk, &timeout, sk->sk_state != TCP_SYN_SENT, &wait))
576 break;
577 if (signal_pending(current) || !timeout)
578 break;
579 }
580 remove_wait_queue(sk_sleep(sk), &wait);
581 return timeout;
582}
583
584static int llc_ui_wait_for_busy_core(struct sock *sk, long timeout)
585{
586 DEFINE_WAIT_FUNC(wait, woken_wake_function);
587 struct llc_sock *llc = llc_sk(sk);
588 int rc;
589
590 add_wait_queue(sk_sleep(sk), &wait);
591 while (1) {
592 rc = 0;
593 if (sk_wait_event(sk, &timeout,
594 (sk->sk_shutdown & RCV_SHUTDOWN) ||
595 (!llc_data_accept_state(llc->state) &&
596 !llc->remote_busy_flag &&
597 !llc->p_flag), &wait))
598 break;
599 rc = -ERESTARTSYS;
600 if (signal_pending(current))
601 break;
602 rc = -EAGAIN;
603 if (!timeout)
604 break;
605 }
606 remove_wait_queue(sk_sleep(sk), &wait);
607 return rc;
608}
609
610static int llc_wait_data(struct sock *sk, long timeo)
611{
612 int rc;
613
614 while (1) {
615 /*
616 * POSIX 1003.1g mandates this order.
617 */
618 rc = sock_error(sk);
619 if (rc)
620 break;
621 rc = 0;
622 if (sk->sk_shutdown & RCV_SHUTDOWN)
623 break;
624 rc = -EAGAIN;
625 if (!timeo)
626 break;
627 rc = sock_intr_errno(timeo);
628 if (signal_pending(current))
629 break;
630 rc = 0;
631 if (sk_wait_data(sk, &timeo, NULL))
632 break;
633 }
634 return rc;
635}
636
637static void llc_cmsg_rcv(struct msghdr *msg, struct sk_buff *skb)
638{
639 struct llc_sock *llc = llc_sk(skb->sk);
640
641 if (llc->cmsg_flags & LLC_CMSG_PKTINFO) {
642 struct llc_pktinfo info;
643
644 memset(&info, 0, sizeof(info));
645 info.lpi_ifindex = llc_sk(skb->sk)->dev->ifindex;
646 llc_pdu_decode_dsap(skb, &info.lpi_sap);
647 llc_pdu_decode_da(skb, info.lpi_mac);
648 put_cmsg(msg, SOL_LLC, LLC_OPT_PKTINFO, sizeof(info), &info);
649 }
650}
651
652/**
653 * llc_ui_accept - accept a new incoming connection.
654 * @sock: Socket which connections arrive on.
655 * @newsock: Socket to move incoming connection to.
656 * @flags: User specified operational flags.
657 * @kern: If the socket is kernel internal
658 *
659 * Accept a new incoming connection.
660 * Returns 0 upon success, negative otherwise.
661 */
662static int llc_ui_accept(struct socket *sock, struct socket *newsock, int flags,
663 bool kern)
664{
665 struct sock *sk = sock->sk, *newsk;
666 struct llc_sock *llc, *newllc;
667 struct sk_buff *skb;
668 int rc = -EOPNOTSUPP;
669
670 dprintk("%s: accepting on %02X\n", __func__,
671 llc_sk(sk)->laddr.lsap);
672 lock_sock(sk);
673 if (unlikely(sk->sk_type != SOCK_STREAM))
674 goto out;
675 rc = -EINVAL;
676 if (unlikely(sock->state != SS_UNCONNECTED ||
677 sk->sk_state != TCP_LISTEN))
678 goto out;
679 /* wait for a connection to arrive. */
680 if (skb_queue_empty(&sk->sk_receive_queue)) {
681 rc = llc_wait_data(sk, sk->sk_rcvtimeo);
682 if (rc)
683 goto out;
684 }
685 dprintk("%s: got a new connection on %02X\n", __func__,
686 llc_sk(sk)->laddr.lsap);
687 skb = skb_dequeue(&sk->sk_receive_queue);
688 rc = -EINVAL;
689 if (!skb->sk)
690 goto frees;
691 rc = 0;
692 newsk = skb->sk;
693 /* attach connection to a new socket. */
694 llc_ui_sk_init(newsock, newsk);
695 sock_reset_flag(newsk, SOCK_ZAPPED);
696 newsk->sk_state = TCP_ESTABLISHED;
697 newsock->state = SS_CONNECTED;
698 llc = llc_sk(sk);
699 newllc = llc_sk(newsk);
700 memcpy(&newllc->addr, &llc->addr, sizeof(newllc->addr));
701 newllc->link = llc_ui_next_link_no(newllc->laddr.lsap);
702
703 /* put original socket back into a clean listen state. */
704 sk->sk_state = TCP_LISTEN;
705 sk->sk_ack_backlog--;
706 dprintk("%s: ok success on %02X, client on %02X\n", __func__,
707 llc_sk(sk)->addr.sllc_sap, newllc->daddr.lsap);
708frees:
709 kfree_skb(skb);
710out:
711 release_sock(sk);
712 return rc;
713}
714
715/**
716 * llc_ui_recvmsg - copy received data to the socket user.
717 * @sock: Socket to copy data from.
718 * @msg: Various user space related information.
719 * @len: Size of user buffer.
720 * @flags: User specified flags.
721 *
722 * Copy received data to the socket user.
723 * Returns non-negative upon success, negative otherwise.
724 */
725static int llc_ui_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
726 int flags)
727{
728 DECLARE_SOCKADDR(struct sockaddr_llc *, uaddr, msg->msg_name);
729 const int nonblock = flags & MSG_DONTWAIT;
730 struct sk_buff *skb = NULL;
731 struct sock *sk = sock->sk;
732 struct llc_sock *llc = llc_sk(sk);
733 unsigned long cpu_flags;
734 size_t copied = 0;
735 u32 peek_seq = 0;
736 u32 *seq, skb_len;
737 unsigned long used;
738 int target; /* Read at least this many bytes */
739 long timeo;
740
741 lock_sock(sk);
742 copied = -ENOTCONN;
743 if (unlikely(sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_LISTEN))
744 goto out;
745
746 timeo = sock_rcvtimeo(sk, nonblock);
747
748 seq = &llc->copied_seq;
749 if (flags & MSG_PEEK) {
750 peek_seq = llc->copied_seq;
751 seq = &peek_seq;
752 }
753
754 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
755 copied = 0;
756
757 do {
758 u32 offset;
759
760 /*
761 * We need to check signals first, to get correct SIGURG
762 * handling. FIXME: Need to check this doesn't impact 1003.1g
763 * and move it down to the bottom of the loop
764 */
765 if (signal_pending(current)) {
766 if (copied)
767 break;
768 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN;
769 break;
770 }
771
772 /* Next get a buffer. */
773
774 skb = skb_peek(&sk->sk_receive_queue);
775 if (skb) {
776 offset = *seq;
777 goto found_ok_skb;
778 }
779 /* Well, if we have backlog, try to process it now yet. */
780
781 if (copied >= target && !sk->sk_backlog.tail)
782 break;
783
784 if (copied) {
785 if (sk->sk_err ||
786 sk->sk_state == TCP_CLOSE ||
787 (sk->sk_shutdown & RCV_SHUTDOWN) ||
788 !timeo ||
789 (flags & MSG_PEEK))
790 break;
791 } else {
792 if (sock_flag(sk, SOCK_DONE))
793 break;
794
795 if (sk->sk_err) {
796 copied = sock_error(sk);
797 break;
798 }
799 if (sk->sk_shutdown & RCV_SHUTDOWN)
800 break;
801
802 if (sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_CLOSE) {
803 if (!sock_flag(sk, SOCK_DONE)) {
804 /*
805 * This occurs when user tries to read
806 * from never connected socket.
807 */
808 copied = -ENOTCONN;
809 break;
810 }
811 break;
812 }
813 if (!timeo) {
814 copied = -EAGAIN;
815 break;
816 }
817 }
818
819 if (copied >= target) { /* Do not sleep, just process backlog. */
820 release_sock(sk);
821 lock_sock(sk);
822 } else
823 sk_wait_data(sk, &timeo, NULL);
824
825 if ((flags & MSG_PEEK) && peek_seq != llc->copied_seq) {
826 net_dbg_ratelimited("LLC(%s:%d): Application bug, race in MSG_PEEK\n",
827 current->comm,
828 task_pid_nr(current));
829 peek_seq = llc->copied_seq;
830 }
831 continue;
832 found_ok_skb:
833 skb_len = skb->len;
834 /* Ok so how much can we use? */
835 used = skb->len - offset;
836 if (len < used)
837 used = len;
838
839 if (!(flags & MSG_TRUNC)) {
840 int rc = skb_copy_datagram_msg(skb, offset, msg, used);
841 if (rc) {
842 /* Exception. Bailout! */
843 if (!copied)
844 copied = -EFAULT;
845 break;
846 }
847 }
848
849 *seq += used;
850 copied += used;
851 len -= used;
852
853 /* For non stream protcols we get one packet per recvmsg call */
854 if (sk->sk_type != SOCK_STREAM)
855 goto copy_uaddr;
856
857 if (!(flags & MSG_PEEK)) {
858 spin_lock_irqsave(&sk->sk_receive_queue.lock, cpu_flags);
859 sk_eat_skb(sk, skb);
860 spin_unlock_irqrestore(&sk->sk_receive_queue.lock, cpu_flags);
861 *seq = 0;
862 }
863
864 /* Partial read */
865 if (used + offset < skb_len)
866 continue;
867 } while (len > 0);
868
869out:
870 release_sock(sk);
871 return copied;
872copy_uaddr:
873 if (uaddr != NULL && skb != NULL) {
874 memcpy(uaddr, llc_ui_skb_cb(skb), sizeof(*uaddr));
875 msg->msg_namelen = sizeof(*uaddr);
876 }
877 if (llc_sk(sk)->cmsg_flags)
878 llc_cmsg_rcv(msg, skb);
879
880 if (!(flags & MSG_PEEK)) {
881 spin_lock_irqsave(&sk->sk_receive_queue.lock, cpu_flags);
882 sk_eat_skb(sk, skb);
883 spin_unlock_irqrestore(&sk->sk_receive_queue.lock, cpu_flags);
884 *seq = 0;
885 }
886
887 goto out;
888}
889
890/**
891 * llc_ui_sendmsg - Transmit data provided by the socket user.
892 * @sock: Socket to transmit data from.
893 * @msg: Various user related information.
894 * @len: Length of data to transmit.
895 *
896 * Transmit data provided by the socket user.
897 * Returns non-negative upon success, negative otherwise.
898 */
899static int llc_ui_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
900{
901 struct sock *sk = sock->sk;
902 struct llc_sock *llc = llc_sk(sk);
903 DECLARE_SOCKADDR(struct sockaddr_llc *, addr, msg->msg_name);
904 int flags = msg->msg_flags;
905 int noblock = flags & MSG_DONTWAIT;
906 struct sk_buff *skb;
907 size_t size = 0;
908 int rc = -EINVAL, copied = 0, hdrlen;
909
910 dprintk("%s: sending from %02X to %02X\n", __func__,
911 llc->laddr.lsap, llc->daddr.lsap);
912 lock_sock(sk);
913 if (addr) {
914 if (msg->msg_namelen < sizeof(*addr))
915 goto release;
916 } else {
917 if (llc_ui_addr_null(&llc->addr))
918 goto release;
919 addr = &llc->addr;
920 }
921 /* must bind connection to sap if user hasn't done it. */
922 if (sock_flag(sk, SOCK_ZAPPED)) {
923 /* bind to sap with null dev, exclusive. */
924 rc = llc_ui_autobind(sock, addr);
925 if (rc)
926 goto release;
927 }
928 hdrlen = llc->dev->hard_header_len + llc_ui_header_len(sk, addr);
929 size = hdrlen + len;
930 if (size > llc->dev->mtu)
931 size = llc->dev->mtu;
932 copied = size - hdrlen;
933 rc = -EINVAL;
934 if (copied < 0)
935 goto release;
936 release_sock(sk);
937 skb = sock_alloc_send_skb(sk, size, noblock, &rc);
938 lock_sock(sk);
939 if (!skb)
940 goto release;
941 skb->dev = llc->dev;
942 skb->protocol = llc_proto_type(addr->sllc_arphrd);
943 skb_reserve(skb, hdrlen);
944 rc = memcpy_from_msg(skb_put(skb, copied), msg, copied);
945 if (rc)
946 goto out;
947 if (sk->sk_type == SOCK_DGRAM || addr->sllc_ua) {
948 llc_build_and_send_ui_pkt(llc->sap, skb, addr->sllc_mac,
949 addr->sllc_sap);
950 goto out;
951 }
952 if (addr->sllc_test) {
953 llc_build_and_send_test_pkt(llc->sap, skb, addr->sllc_mac,
954 addr->sllc_sap);
955 goto out;
956 }
957 if (addr->sllc_xid) {
958 llc_build_and_send_xid_pkt(llc->sap, skb, addr->sllc_mac,
959 addr->sllc_sap);
960 goto out;
961 }
962 rc = -ENOPROTOOPT;
963 if (!(sk->sk_type == SOCK_STREAM && !addr->sllc_ua))
964 goto out;
965 rc = llc_ui_send_data(sk, skb, noblock);
966out:
967 if (rc) {
968 kfree_skb(skb);
969release:
970 dprintk("%s: failed sending from %02X to %02X: %d\n",
971 __func__, llc->laddr.lsap, llc->daddr.lsap, rc);
972 }
973 release_sock(sk);
974 return rc ? : copied;
975}
976
977/**
978 * llc_ui_getname - return the address info of a socket
979 * @sock: Socket to get address of.
980 * @uaddr: Address structure to return information.
981 * @uaddrlen: Length of address structure.
982 * @peer: Does user want local or remote address information.
983 *
984 * Return the address information of a socket.
985 */
986static int llc_ui_getname(struct socket *sock, struct sockaddr *uaddr,
987 int peer)
988{
989 struct sockaddr_llc sllc;
990 struct sock *sk = sock->sk;
991 struct llc_sock *llc = llc_sk(sk);
992 int rc = -EBADF;
993
994 memset(&sllc, 0, sizeof(sllc));
995 lock_sock(sk);
996 if (sock_flag(sk, SOCK_ZAPPED))
997 goto out;
998 if (peer) {
999 rc = -ENOTCONN;
1000 if (sk->sk_state != TCP_ESTABLISHED)
1001 goto out;
1002 if(llc->dev)
1003 sllc.sllc_arphrd = llc->dev->type;
1004 sllc.sllc_sap = llc->daddr.lsap;
1005 memcpy(&sllc.sllc_mac, &llc->daddr.mac, IFHWADDRLEN);
1006 } else {
1007 rc = -EINVAL;
1008 if (!llc->sap)
1009 goto out;
1010 sllc.sllc_sap = llc->sap->laddr.lsap;
1011
1012 if (llc->dev) {
1013 sllc.sllc_arphrd = llc->dev->type;
1014 memcpy(&sllc.sllc_mac, llc->dev->dev_addr,
1015 IFHWADDRLEN);
1016 }
1017 }
1018 sllc.sllc_family = AF_LLC;
1019 memcpy(uaddr, &sllc, sizeof(sllc));
1020 rc = sizeof(sllc);
1021out:
1022 release_sock(sk);
1023 return rc;
1024}
1025
1026/**
1027 * llc_ui_ioctl - io controls for PF_LLC
1028 * @sock: Socket to get/set info
1029 * @cmd: command
1030 * @arg: optional argument for cmd
1031 *
1032 * get/set info on llc sockets
1033 */
1034static int llc_ui_ioctl(struct socket *sock, unsigned int cmd,
1035 unsigned long arg)
1036{
1037 return -ENOIOCTLCMD;
1038}
1039
1040/**
1041 * llc_ui_setsockopt - set various connection specific parameters.
1042 * @sock: Socket to set options on.
1043 * @level: Socket level user is requesting operations on.
1044 * @optname: Operation name.
1045 * @optval: User provided operation data.
1046 * @optlen: Length of optval.
1047 *
1048 * Set various connection specific parameters.
1049 */
1050static int llc_ui_setsockopt(struct socket *sock, int level, int optname,
1051 char __user *optval, unsigned int optlen)
1052{
1053 struct sock *sk = sock->sk;
1054 struct llc_sock *llc = llc_sk(sk);
1055 unsigned int opt;
1056 int rc = -EINVAL;
1057
1058 lock_sock(sk);
1059 if (unlikely(level != SOL_LLC || optlen != sizeof(int)))
1060 goto out;
1061 rc = get_user(opt, (int __user *)optval);
1062 if (rc)
1063 goto out;
1064 rc = -EINVAL;
1065 switch (optname) {
1066 case LLC_OPT_RETRY:
1067 if (opt > LLC_OPT_MAX_RETRY)
1068 goto out;
1069 llc->n2 = opt;
1070 break;
1071 case LLC_OPT_SIZE:
1072 if (opt > LLC_OPT_MAX_SIZE)
1073 goto out;
1074 llc->n1 = opt;
1075 break;
1076 case LLC_OPT_ACK_TMR_EXP:
1077 if (opt > LLC_OPT_MAX_ACK_TMR_EXP)
1078 goto out;
1079 llc->ack_timer.expire = opt * HZ;
1080 break;
1081 case LLC_OPT_P_TMR_EXP:
1082 if (opt > LLC_OPT_MAX_P_TMR_EXP)
1083 goto out;
1084 llc->pf_cycle_timer.expire = opt * HZ;
1085 break;
1086 case LLC_OPT_REJ_TMR_EXP:
1087 if (opt > LLC_OPT_MAX_REJ_TMR_EXP)
1088 goto out;
1089 llc->rej_sent_timer.expire = opt * HZ;
1090 break;
1091 case LLC_OPT_BUSY_TMR_EXP:
1092 if (opt > LLC_OPT_MAX_BUSY_TMR_EXP)
1093 goto out;
1094 llc->busy_state_timer.expire = opt * HZ;
1095 break;
1096 case LLC_OPT_TX_WIN:
1097 if (opt > LLC_OPT_MAX_WIN)
1098 goto out;
1099 llc->k = opt;
1100 break;
1101 case LLC_OPT_RX_WIN:
1102 if (opt > LLC_OPT_MAX_WIN)
1103 goto out;
1104 llc->rw = opt;
1105 break;
1106 case LLC_OPT_PKTINFO:
1107 if (opt)
1108 llc->cmsg_flags |= LLC_CMSG_PKTINFO;
1109 else
1110 llc->cmsg_flags &= ~LLC_CMSG_PKTINFO;
1111 break;
1112 default:
1113 rc = -ENOPROTOOPT;
1114 goto out;
1115 }
1116 rc = 0;
1117out:
1118 release_sock(sk);
1119 return rc;
1120}
1121
1122/**
1123 * llc_ui_getsockopt - get connection specific socket info
1124 * @sock: Socket to get information from.
1125 * @level: Socket level user is requesting operations on.
1126 * @optname: Operation name.
1127 * @optval: Variable to return operation data in.
1128 * @optlen: Length of optval.
1129 *
1130 * Get connection specific socket information.
1131 */
1132static int llc_ui_getsockopt(struct socket *sock, int level, int optname,
1133 char __user *optval, int __user *optlen)
1134{
1135 struct sock *sk = sock->sk;
1136 struct llc_sock *llc = llc_sk(sk);
1137 int val = 0, len = 0, rc = -EINVAL;
1138
1139 lock_sock(sk);
1140 if (unlikely(level != SOL_LLC))
1141 goto out;
1142 rc = get_user(len, optlen);
1143 if (rc)
1144 goto out;
1145 rc = -EINVAL;
1146 if (len != sizeof(int))
1147 goto out;
1148 switch (optname) {
1149 case LLC_OPT_RETRY:
1150 val = llc->n2; break;
1151 case LLC_OPT_SIZE:
1152 val = llc->n1; break;
1153 case LLC_OPT_ACK_TMR_EXP:
1154 val = llc->ack_timer.expire / HZ; break;
1155 case LLC_OPT_P_TMR_EXP:
1156 val = llc->pf_cycle_timer.expire / HZ; break;
1157 case LLC_OPT_REJ_TMR_EXP:
1158 val = llc->rej_sent_timer.expire / HZ; break;
1159 case LLC_OPT_BUSY_TMR_EXP:
1160 val = llc->busy_state_timer.expire / HZ; break;
1161 case LLC_OPT_TX_WIN:
1162 val = llc->k; break;
1163 case LLC_OPT_RX_WIN:
1164 val = llc->rw; break;
1165 case LLC_OPT_PKTINFO:
1166 val = (llc->cmsg_flags & LLC_CMSG_PKTINFO) != 0;
1167 break;
1168 default:
1169 rc = -ENOPROTOOPT;
1170 goto out;
1171 }
1172 rc = 0;
1173 if (put_user(len, optlen) || copy_to_user(optval, &val, len))
1174 rc = -EFAULT;
1175out:
1176 release_sock(sk);
1177 return rc;
1178}
1179
1180static const struct net_proto_family llc_ui_family_ops = {
1181 .family = PF_LLC,
1182 .create = llc_ui_create,
1183 .owner = THIS_MODULE,
1184};
1185
1186static const struct proto_ops llc_ui_ops = {
1187 .family = PF_LLC,
1188 .owner = THIS_MODULE,
1189 .release = llc_ui_release,
1190 .bind = llc_ui_bind,
1191 .connect = llc_ui_connect,
1192 .socketpair = sock_no_socketpair,
1193 .accept = llc_ui_accept,
1194 .getname = llc_ui_getname,
1195 .poll = datagram_poll,
1196 .ioctl = llc_ui_ioctl,
1197 .listen = llc_ui_listen,
1198 .shutdown = llc_ui_shutdown,
1199 .setsockopt = llc_ui_setsockopt,
1200 .getsockopt = llc_ui_getsockopt,
1201 .sendmsg = llc_ui_sendmsg,
1202 .recvmsg = llc_ui_recvmsg,
1203 .mmap = sock_no_mmap,
1204 .sendpage = sock_no_sendpage,
1205};
1206
1207static const char llc_proc_err_msg[] __initconst =
1208 KERN_CRIT "LLC: Unable to register the proc_fs entries\n";
1209static const char llc_sysctl_err_msg[] __initconst =
1210 KERN_CRIT "LLC: Unable to register the sysctl entries\n";
1211static const char llc_sock_err_msg[] __initconst =
1212 KERN_CRIT "LLC: Unable to register the network family\n";
1213
1214static int __init llc2_init(void)
1215{
1216 int rc = proto_register(&llc_proto, 0);
1217
1218 if (rc != 0)
1219 goto out;
1220
1221 llc_build_offset_table();
1222 llc_station_init();
1223 llc_ui_sap_last_autoport = LLC_SAP_DYN_START;
1224 rc = llc_proc_init();
1225 if (rc != 0) {
1226 printk(llc_proc_err_msg);
1227 goto out_station;
1228 }
1229 rc = llc_sysctl_init();
1230 if (rc) {
1231 printk(llc_sysctl_err_msg);
1232 goto out_proc;
1233 }
1234 rc = sock_register(&llc_ui_family_ops);
1235 if (rc) {
1236 printk(llc_sock_err_msg);
1237 goto out_sysctl;
1238 }
1239 llc_add_pack(LLC_DEST_SAP, llc_sap_handler);
1240 llc_add_pack(LLC_DEST_CONN, llc_conn_handler);
1241out:
1242 return rc;
1243out_sysctl:
1244 llc_sysctl_exit();
1245out_proc:
1246 llc_proc_exit();
1247out_station:
1248 llc_station_exit();
1249 proto_unregister(&llc_proto);
1250 goto out;
1251}
1252
1253static void __exit llc2_exit(void)
1254{
1255 llc_station_exit();
1256 llc_remove_pack(LLC_DEST_SAP);
1257 llc_remove_pack(LLC_DEST_CONN);
1258 sock_unregister(PF_LLC);
1259 llc_proc_exit();
1260 llc_sysctl_exit();
1261 proto_unregister(&llc_proto);
1262}
1263
1264module_init(llc2_init);
1265module_exit(llc2_exit);
1266
1267MODULE_LICENSE("GPL");
1268MODULE_AUTHOR("Procom 1997, Jay Schullist 2001, Arnaldo C. Melo 2001-2003");
1269MODULE_DESCRIPTION("IEEE 802.2 PF_LLC support");
1270MODULE_ALIAS_NETPROTO(PF_LLC);