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(p: addr, q: &llc_ui_addrnull, size: 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, parent: 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(ns: net->user_ns, CAP_NET_RAW))
178 return -EPERM;
179
180 if (!net_eq(net1: net, net2: &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, prot: &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, timeout: sk->sk_rcvtimeo);
214 if (!sock_flag(sk, flag: 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(sap: llc->sap, sk);
222 release_sock(sk);
223 llc_sap_put(sap);
224 } else {
225 release_sock(sk);
226 }
227 netdev_put(dev: llc->dev, tracker: &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(sap_value: 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, flag: 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(net: &init_net, ifindex: 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(net: &init_net, type: 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(lsap: 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(dev: llc->dev, tracker: &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, flag: 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(net: &init_net, ifindex: sk->sk_bound_dev_if);
360 if (dev) {
361 if (is_zero_ether_addr(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(addr1: addr->sllc_mac,
366 addr2: dev->dev_addr)) {
367 rc = -EINVAL;
368 dev = NULL;
369 }
370 }
371 } else {
372 dev = dev_getbyhwaddr_rcu(net: &init_net, type: addr->sllc_arphrd,
373 hwaddr: 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(sap_value: addr->sllc_sap);
387 if (!sap) {
388 sap = llc_sap_open(lsap: 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: &daddr, laddr: &laddr, net: &init_net);
406 if (ask) {
407 sock_put(sk: 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(dev: llc->dev, tracker: &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, flag: 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, timeout: 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, flag: 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(sap: llc->sap->laddr.lsap);
509 rc = llc_establish_connection(sk, lmac: llc->dev->dev_addr,
510 dmac: addr->sllc_mac, dsap: 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, noblock: flags & O_NONBLOCK);
520
521 if (!timeo || !llc_ui_wait_for_conn(sk, timeout: 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, flag: 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(wq_head: sk_sleep(sk), wq_entry: &wait);
585 while (1) {
586 if (sk_wait_event(sk, &timeout,
587 READ_ONCE(sk->sk_state) == TCP_CLOSE, &wait))
588 break;
589 rc = -ERESTARTSYS;
590 if (signal_pending(current))
591 break;
592 rc = -EAGAIN;
593 if (!timeout)
594 break;
595 rc = 0;
596 }
597 remove_wait_queue(wq_head: sk_sleep(sk), wq_entry: &wait);
598 return rc;
599}
600
601static bool llc_ui_wait_for_conn(struct sock *sk, long timeout)
602{
603 DEFINE_WAIT_FUNC(wait, woken_wake_function);
604
605 add_wait_queue(wq_head: sk_sleep(sk), wq_entry: &wait);
606 while (1) {
607 if (sk_wait_event(sk, &timeout,
608 READ_ONCE(sk->sk_state) != TCP_SYN_SENT, &wait))
609 break;
610 if (signal_pending(current) || !timeout)
611 break;
612 }
613 remove_wait_queue(wq_head: sk_sleep(sk), wq_entry: &wait);
614 return timeout;
615}
616
617static int llc_ui_wait_for_busy_core(struct sock *sk, long timeout)
618{
619 DEFINE_WAIT_FUNC(wait, woken_wake_function);
620 struct llc_sock *llc = llc_sk(sk);
621 int rc;
622
623 add_wait_queue(wq_head: sk_sleep(sk), wq_entry: &wait);
624 while (1) {
625 rc = 0;
626 if (sk_wait_event(sk, &timeout,
627 (READ_ONCE(sk->sk_shutdown) & RCV_SHUTDOWN) ||
628 (!llc_data_accept_state(llc->state) &&
629 !llc->remote_busy_flag &&
630 !llc->p_flag), &wait))
631 break;
632 rc = -ERESTARTSYS;
633 if (signal_pending(current))
634 break;
635 rc = -EAGAIN;
636 if (!timeout)
637 break;
638 }
639 remove_wait_queue(wq_head: sk_sleep(sk), wq_entry: &wait);
640 return rc;
641}
642
643static int llc_wait_data(struct sock *sk, long timeo)
644{
645 int rc;
646
647 while (1) {
648 /*
649 * POSIX 1003.1g mandates this order.
650 */
651 rc = sock_error(sk);
652 if (rc)
653 break;
654 rc = 0;
655 if (sk->sk_shutdown & RCV_SHUTDOWN)
656 break;
657 rc = -EAGAIN;
658 if (!timeo)
659 break;
660 rc = sock_intr_errno(timeo);
661 if (signal_pending(current))
662 break;
663 rc = 0;
664 if (sk_wait_data(sk, timeo: &timeo, NULL))
665 break;
666 }
667 return rc;
668}
669
670static void llc_cmsg_rcv(struct msghdr *msg, struct sk_buff *skb)
671{
672 struct llc_sock *llc = llc_sk(sk: skb->sk);
673
674 if (llc->cmsg_flags & LLC_CMSG_PKTINFO) {
675 struct llc_pktinfo info;
676
677 memset(&info, 0, sizeof(info));
678 info.lpi_ifindex = llc_sk(sk: skb->sk)->dev->ifindex;
679 llc_pdu_decode_dsap(skb, dsap: &info.lpi_sap);
680 llc_pdu_decode_da(skb, da: info.lpi_mac);
681 put_cmsg(msg, SOL_LLC, type: LLC_OPT_PKTINFO, len: sizeof(info), data: &info);
682 }
683}
684
685/**
686 * llc_ui_accept - accept a new incoming connection.
687 * @sock: Socket which connections arrive on.
688 * @newsock: Socket to move incoming connection to.
689 * @flags: User specified operational flags.
690 * @kern: If the socket is kernel internal
691 *
692 * Accept a new incoming connection.
693 * Returns 0 upon success, negative otherwise.
694 */
695static int llc_ui_accept(struct socket *sock, struct socket *newsock, int flags,
696 bool kern)
697{
698 struct sock *sk = sock->sk, *newsk;
699 struct llc_sock *llc, *newllc;
700 struct sk_buff *skb;
701 int rc = -EOPNOTSUPP;
702
703 dprintk("%s: accepting on %02X\n", __func__,
704 llc_sk(sk)->laddr.lsap);
705 lock_sock(sk);
706 if (unlikely(sk->sk_type != SOCK_STREAM))
707 goto out;
708 rc = -EINVAL;
709 if (unlikely(sock->state != SS_UNCONNECTED ||
710 sk->sk_state != TCP_LISTEN))
711 goto out;
712 /* wait for a connection to arrive. */
713 if (skb_queue_empty(list: &sk->sk_receive_queue)) {
714 rc = llc_wait_data(sk, timeo: sk->sk_rcvtimeo);
715 if (rc)
716 goto out;
717 }
718 dprintk("%s: got a new connection on %02X\n", __func__,
719 llc_sk(sk)->laddr.lsap);
720 skb = skb_dequeue(list: &sk->sk_receive_queue);
721 rc = -EINVAL;
722 if (!skb->sk)
723 goto frees;
724 rc = 0;
725 newsk = skb->sk;
726 /* attach connection to a new socket. */
727 llc_ui_sk_init(sock: newsock, sk: newsk);
728 sock_reset_flag(sk: newsk, flag: SOCK_ZAPPED);
729 newsk->sk_state = TCP_ESTABLISHED;
730 newsock->state = SS_CONNECTED;
731 llc = llc_sk(sk);
732 newllc = llc_sk(sk: newsk);
733 memcpy(&newllc->addr, &llc->addr, sizeof(newllc->addr));
734 newllc->link = llc_ui_next_link_no(sap: newllc->laddr.lsap);
735
736 /* put original socket back into a clean listen state. */
737 sk->sk_state = TCP_LISTEN;
738 sk_acceptq_removed(sk);
739 dprintk("%s: ok success on %02X, client on %02X\n", __func__,
740 llc_sk(sk)->addr.sllc_sap, newllc->daddr.lsap);
741frees:
742 kfree_skb(skb);
743out:
744 release_sock(sk);
745 return rc;
746}
747
748/**
749 * llc_ui_recvmsg - copy received data to the socket user.
750 * @sock: Socket to copy data from.
751 * @msg: Various user space related information.
752 * @len: Size of user buffer.
753 * @flags: User specified flags.
754 *
755 * Copy received data to the socket user.
756 * Returns non-negative upon success, negative otherwise.
757 */
758static int llc_ui_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
759 int flags)
760{
761 DECLARE_SOCKADDR(struct sockaddr_llc *, uaddr, msg->msg_name);
762 const int nonblock = flags & MSG_DONTWAIT;
763 struct sk_buff *skb = NULL;
764 struct sock *sk = sock->sk;
765 struct llc_sock *llc = llc_sk(sk);
766 size_t copied = 0;
767 u32 peek_seq = 0;
768 u32 *seq, skb_len;
769 unsigned long used;
770 int target; /* Read at least this many bytes */
771 long timeo;
772
773 lock_sock(sk);
774 copied = -ENOTCONN;
775 if (unlikely(sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_LISTEN))
776 goto out;
777
778 timeo = sock_rcvtimeo(sk, noblock: nonblock);
779
780 seq = &llc->copied_seq;
781 if (flags & MSG_PEEK) {
782 peek_seq = llc->copied_seq;
783 seq = &peek_seq;
784 }
785
786 target = sock_rcvlowat(sk, waitall: flags & MSG_WAITALL, len);
787 copied = 0;
788
789 do {
790 u32 offset;
791
792 /*
793 * We need to check signals first, to get correct SIGURG
794 * handling. FIXME: Need to check this doesn't impact 1003.1g
795 * and move it down to the bottom of the loop
796 */
797 if (signal_pending(current)) {
798 if (copied)
799 break;
800 copied = timeo ? sock_intr_errno(timeo) : -EAGAIN;
801 break;
802 }
803
804 /* Next get a buffer. */
805
806 skb = skb_peek(list_: &sk->sk_receive_queue);
807 if (skb) {
808 offset = *seq;
809 goto found_ok_skb;
810 }
811 /* Well, if we have backlog, try to process it now yet. */
812
813 if (copied >= target && !READ_ONCE(sk->sk_backlog.tail))
814 break;
815
816 if (copied) {
817 if (sk->sk_err ||
818 sk->sk_state == TCP_CLOSE ||
819 (sk->sk_shutdown & RCV_SHUTDOWN) ||
820 !timeo ||
821 (flags & MSG_PEEK))
822 break;
823 } else {
824 if (sock_flag(sk, flag: SOCK_DONE))
825 break;
826
827 if (sk->sk_err) {
828 copied = sock_error(sk);
829 break;
830 }
831 if (sk->sk_shutdown & RCV_SHUTDOWN)
832 break;
833
834 if (sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_CLOSE) {
835 if (!sock_flag(sk, flag: SOCK_DONE)) {
836 /*
837 * This occurs when user tries to read
838 * from never connected socket.
839 */
840 copied = -ENOTCONN;
841 break;
842 }
843 break;
844 }
845 if (!timeo) {
846 copied = -EAGAIN;
847 break;
848 }
849 }
850
851 if (copied >= target) { /* Do not sleep, just process backlog. */
852 release_sock(sk);
853 lock_sock(sk);
854 } else
855 sk_wait_data(sk, timeo: &timeo, NULL);
856
857 if ((flags & MSG_PEEK) && peek_seq != llc->copied_seq) {
858 net_dbg_ratelimited("LLC(%s:%d): Application bug, race in MSG_PEEK\n",
859 current->comm,
860 task_pid_nr(current));
861 peek_seq = llc->copied_seq;
862 }
863 continue;
864 found_ok_skb:
865 skb_len = skb->len;
866 /* Ok so how much can we use? */
867 used = skb->len - offset;
868 if (len < used)
869 used = len;
870
871 if (!(flags & MSG_TRUNC)) {
872 int rc = skb_copy_datagram_msg(from: skb, offset, msg, size: used);
873 if (rc) {
874 /* Exception. Bailout! */
875 if (!copied)
876 copied = -EFAULT;
877 break;
878 }
879 }
880
881 *seq += used;
882 copied += used;
883 len -= used;
884
885 /* For non stream protcols we get one packet per recvmsg call */
886 if (sk->sk_type != SOCK_STREAM)
887 goto copy_uaddr;
888
889 if (!(flags & MSG_PEEK)) {
890 skb_unlink(skb, list: &sk->sk_receive_queue);
891 kfree_skb(skb);
892 *seq = 0;
893 }
894
895 /* Partial read */
896 if (used + offset < skb_len)
897 continue;
898 } while (len > 0);
899
900out:
901 release_sock(sk);
902 return copied;
903copy_uaddr:
904 if (uaddr != NULL && skb != NULL) {
905 memcpy(uaddr, llc_ui_skb_cb(skb), sizeof(*uaddr));
906 msg->msg_namelen = sizeof(*uaddr);
907 }
908 if (llc_sk(sk)->cmsg_flags)
909 llc_cmsg_rcv(msg, skb);
910
911 if (!(flags & MSG_PEEK)) {
912 skb_unlink(skb, list: &sk->sk_receive_queue);
913 kfree_skb(skb);
914 *seq = 0;
915 }
916
917 goto out;
918}
919
920/**
921 * llc_ui_sendmsg - Transmit data provided by the socket user.
922 * @sock: Socket to transmit data from.
923 * @msg: Various user related information.
924 * @len: Length of data to transmit.
925 *
926 * Transmit data provided by the socket user.
927 * Returns non-negative upon success, negative otherwise.
928 */
929static int llc_ui_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
930{
931 struct sock *sk = sock->sk;
932 struct llc_sock *llc = llc_sk(sk);
933 DECLARE_SOCKADDR(struct sockaddr_llc *, addr, msg->msg_name);
934 int flags = msg->msg_flags;
935 int noblock = flags & MSG_DONTWAIT;
936 struct sk_buff *skb = NULL;
937 size_t size = 0;
938 int rc = -EINVAL, copied = 0, hdrlen;
939
940 dprintk("%s: sending from %02X to %02X\n", __func__,
941 llc->laddr.lsap, llc->daddr.lsap);
942 lock_sock(sk);
943 if (addr) {
944 if (msg->msg_namelen < sizeof(*addr))
945 goto out;
946 } else {
947 if (llc_ui_addr_null(addr: &llc->addr))
948 goto out;
949 addr = &llc->addr;
950 }
951 /* must bind connection to sap if user hasn't done it. */
952 if (sock_flag(sk, flag: SOCK_ZAPPED)) {
953 /* bind to sap with null dev, exclusive. */
954 rc = llc_ui_autobind(sock, addr);
955 if (rc)
956 goto out;
957 }
958 hdrlen = llc->dev->hard_header_len + llc_ui_header_len(sk, addr);
959 size = hdrlen + len;
960 if (size > llc->dev->mtu)
961 size = llc->dev->mtu;
962 copied = size - hdrlen;
963 rc = -EINVAL;
964 if (copied < 0)
965 goto out;
966 release_sock(sk);
967 skb = sock_alloc_send_skb(sk, size, noblock, errcode: &rc);
968 lock_sock(sk);
969 if (!skb)
970 goto out;
971 skb->dev = llc->dev;
972 skb->protocol = llc_proto_type(arphrd: addr->sllc_arphrd);
973 skb_reserve(skb, len: hdrlen);
974 rc = memcpy_from_msg(data: skb_put(skb, len: copied), msg, len: copied);
975 if (rc)
976 goto out;
977 if (sk->sk_type == SOCK_DGRAM || addr->sllc_ua) {
978 llc_build_and_send_ui_pkt(sap: llc->sap, skb, dmac: addr->sllc_mac,
979 dsap: addr->sllc_sap);
980 skb = NULL;
981 goto out;
982 }
983 if (addr->sllc_test) {
984 llc_build_and_send_test_pkt(sap: llc->sap, skb, dmac: addr->sllc_mac,
985 dsap: addr->sllc_sap);
986 skb = NULL;
987 goto out;
988 }
989 if (addr->sllc_xid) {
990 llc_build_and_send_xid_pkt(sap: llc->sap, skb, dmac: addr->sllc_mac,
991 dsap: addr->sllc_sap);
992 skb = NULL;
993 goto out;
994 }
995 rc = -ENOPROTOOPT;
996 if (!(sk->sk_type == SOCK_STREAM && !addr->sllc_ua))
997 goto out;
998 rc = llc_ui_send_data(sk, skb, noblock);
999 skb = NULL;
1000out:
1001 kfree_skb(skb);
1002 if (rc)
1003 dprintk("%s: failed sending from %02X to %02X: %d\n",
1004 __func__, llc->laddr.lsap, llc->daddr.lsap, rc);
1005 release_sock(sk);
1006 return rc ? : copied;
1007}
1008
1009/**
1010 * llc_ui_getname - return the address info of a socket
1011 * @sock: Socket to get address of.
1012 * @uaddr: Address structure to return information.
1013 * @peer: Does user want local or remote address information.
1014 *
1015 * Return the address information of a socket.
1016 */
1017static int llc_ui_getname(struct socket *sock, struct sockaddr *uaddr,
1018 int peer)
1019{
1020 struct sockaddr_llc sllc;
1021 struct sock *sk = sock->sk;
1022 struct llc_sock *llc = llc_sk(sk);
1023 int rc = -EBADF;
1024
1025 memset(&sllc, 0, sizeof(sllc));
1026 lock_sock(sk);
1027 if (sock_flag(sk, flag: SOCK_ZAPPED))
1028 goto out;
1029 if (peer) {
1030 rc = -ENOTCONN;
1031 if (sk->sk_state != TCP_ESTABLISHED)
1032 goto out;
1033 if(llc->dev)
1034 sllc.sllc_arphrd = llc->dev->type;
1035 sllc.sllc_sap = llc->daddr.lsap;
1036 memcpy(&sllc.sllc_mac, &llc->daddr.mac, IFHWADDRLEN);
1037 } else {
1038 rc = -EINVAL;
1039 if (!llc->sap)
1040 goto out;
1041 sllc.sllc_sap = llc->sap->laddr.lsap;
1042
1043 if (llc->dev) {
1044 sllc.sllc_arphrd = llc->dev->type;
1045 memcpy(&sllc.sllc_mac, llc->dev->dev_addr,
1046 IFHWADDRLEN);
1047 }
1048 }
1049 sllc.sllc_family = AF_LLC;
1050 memcpy(uaddr, &sllc, sizeof(sllc));
1051 rc = sizeof(sllc);
1052out:
1053 release_sock(sk);
1054 return rc;
1055}
1056
1057/**
1058 * llc_ui_ioctl - io controls for PF_LLC
1059 * @sock: Socket to get/set info
1060 * @cmd: command
1061 * @arg: optional argument for cmd
1062 *
1063 * get/set info on llc sockets
1064 */
1065static int llc_ui_ioctl(struct socket *sock, unsigned int cmd,
1066 unsigned long arg)
1067{
1068 return -ENOIOCTLCMD;
1069}
1070
1071/**
1072 * llc_ui_setsockopt - set various connection specific parameters.
1073 * @sock: Socket to set options on.
1074 * @level: Socket level user is requesting operations on.
1075 * @optname: Operation name.
1076 * @optval: User provided operation data.
1077 * @optlen: Length of optval.
1078 *
1079 * Set various connection specific parameters.
1080 */
1081static int llc_ui_setsockopt(struct socket *sock, int level, int optname,
1082 sockptr_t optval, unsigned int optlen)
1083{
1084 struct sock *sk = sock->sk;
1085 struct llc_sock *llc = llc_sk(sk);
1086 unsigned int opt;
1087 int rc = -EINVAL;
1088
1089 lock_sock(sk);
1090 if (unlikely(level != SOL_LLC || optlen != sizeof(int)))
1091 goto out;
1092 rc = copy_from_sockptr(dst: &opt, src: optval, size: sizeof(opt));
1093 if (rc)
1094 goto out;
1095 rc = -EINVAL;
1096 switch (optname) {
1097 case LLC_OPT_RETRY:
1098 if (opt > LLC_OPT_MAX_RETRY)
1099 goto out;
1100 llc->n2 = opt;
1101 break;
1102 case LLC_OPT_SIZE:
1103 if (opt > LLC_OPT_MAX_SIZE)
1104 goto out;
1105 llc->n1 = opt;
1106 break;
1107 case LLC_OPT_ACK_TMR_EXP:
1108 if (opt > LLC_OPT_MAX_ACK_TMR_EXP)
1109 goto out;
1110 llc->ack_timer.expire = opt * HZ;
1111 break;
1112 case LLC_OPT_P_TMR_EXP:
1113 if (opt > LLC_OPT_MAX_P_TMR_EXP)
1114 goto out;
1115 llc->pf_cycle_timer.expire = opt * HZ;
1116 break;
1117 case LLC_OPT_REJ_TMR_EXP:
1118 if (opt > LLC_OPT_MAX_REJ_TMR_EXP)
1119 goto out;
1120 llc->rej_sent_timer.expire = opt * HZ;
1121 break;
1122 case LLC_OPT_BUSY_TMR_EXP:
1123 if (opt > LLC_OPT_MAX_BUSY_TMR_EXP)
1124 goto out;
1125 llc->busy_state_timer.expire = opt * HZ;
1126 break;
1127 case LLC_OPT_TX_WIN:
1128 if (opt > LLC_OPT_MAX_WIN)
1129 goto out;
1130 llc->k = opt;
1131 break;
1132 case LLC_OPT_RX_WIN:
1133 if (opt > LLC_OPT_MAX_WIN)
1134 goto out;
1135 llc->rw = opt;
1136 break;
1137 case LLC_OPT_PKTINFO:
1138 if (opt)
1139 llc->cmsg_flags |= LLC_CMSG_PKTINFO;
1140 else
1141 llc->cmsg_flags &= ~LLC_CMSG_PKTINFO;
1142 break;
1143 default:
1144 rc = -ENOPROTOOPT;
1145 goto out;
1146 }
1147 rc = 0;
1148out:
1149 release_sock(sk);
1150 return rc;
1151}
1152
1153/**
1154 * llc_ui_getsockopt - get connection specific socket info
1155 * @sock: Socket to get information from.
1156 * @level: Socket level user is requesting operations on.
1157 * @optname: Operation name.
1158 * @optval: Variable to return operation data in.
1159 * @optlen: Length of optval.
1160 *
1161 * Get connection specific socket information.
1162 */
1163static int llc_ui_getsockopt(struct socket *sock, int level, int optname,
1164 char __user *optval, int __user *optlen)
1165{
1166 struct sock *sk = sock->sk;
1167 struct llc_sock *llc = llc_sk(sk);
1168 int val = 0, len = 0, rc = -EINVAL;
1169
1170 lock_sock(sk);
1171 if (unlikely(level != SOL_LLC))
1172 goto out;
1173 rc = get_user(len, optlen);
1174 if (rc)
1175 goto out;
1176 rc = -EINVAL;
1177 if (len != sizeof(int))
1178 goto out;
1179 switch (optname) {
1180 case LLC_OPT_RETRY:
1181 val = llc->n2; break;
1182 case LLC_OPT_SIZE:
1183 val = llc->n1; break;
1184 case LLC_OPT_ACK_TMR_EXP:
1185 val = llc->ack_timer.expire / HZ; break;
1186 case LLC_OPT_P_TMR_EXP:
1187 val = llc->pf_cycle_timer.expire / HZ; break;
1188 case LLC_OPT_REJ_TMR_EXP:
1189 val = llc->rej_sent_timer.expire / HZ; break;
1190 case LLC_OPT_BUSY_TMR_EXP:
1191 val = llc->busy_state_timer.expire / HZ; break;
1192 case LLC_OPT_TX_WIN:
1193 val = llc->k; break;
1194 case LLC_OPT_RX_WIN:
1195 val = llc->rw; break;
1196 case LLC_OPT_PKTINFO:
1197 val = (llc->cmsg_flags & LLC_CMSG_PKTINFO) != 0;
1198 break;
1199 default:
1200 rc = -ENOPROTOOPT;
1201 goto out;
1202 }
1203 rc = 0;
1204 if (put_user(len, optlen) || copy_to_user(to: optval, from: &val, n: len))
1205 rc = -EFAULT;
1206out:
1207 release_sock(sk);
1208 return rc;
1209}
1210
1211static const struct net_proto_family llc_ui_family_ops = {
1212 .family = PF_LLC,
1213 .create = llc_ui_create,
1214 .owner = THIS_MODULE,
1215};
1216
1217static const struct proto_ops llc_ui_ops = {
1218 .family = PF_LLC,
1219 .owner = THIS_MODULE,
1220 .release = llc_ui_release,
1221 .bind = llc_ui_bind,
1222 .connect = llc_ui_connect,
1223 .socketpair = sock_no_socketpair,
1224 .accept = llc_ui_accept,
1225 .getname = llc_ui_getname,
1226 .poll = datagram_poll,
1227 .ioctl = llc_ui_ioctl,
1228 .listen = llc_ui_listen,
1229 .shutdown = llc_ui_shutdown,
1230 .setsockopt = llc_ui_setsockopt,
1231 .getsockopt = llc_ui_getsockopt,
1232 .sendmsg = llc_ui_sendmsg,
1233 .recvmsg = llc_ui_recvmsg,
1234 .mmap = sock_no_mmap,
1235};
1236
1237static const char llc_proc_err_msg[] __initconst =
1238 KERN_CRIT "LLC: Unable to register the proc_fs entries\n";
1239static const char llc_sysctl_err_msg[] __initconst =
1240 KERN_CRIT "LLC: Unable to register the sysctl entries\n";
1241static const char llc_sock_err_msg[] __initconst =
1242 KERN_CRIT "LLC: Unable to register the network family\n";
1243
1244static int __init llc2_init(void)
1245{
1246 int rc = proto_register(prot: &llc_proto, alloc_slab: 0);
1247
1248 if (rc != 0)
1249 goto out;
1250
1251 llc_build_offset_table();
1252 llc_station_init();
1253 llc_ui_sap_last_autoport = LLC_SAP_DYN_START;
1254 rc = llc_proc_init();
1255 if (rc != 0) {
1256 printk(llc_proc_err_msg);
1257 goto out_station;
1258 }
1259 rc = llc_sysctl_init();
1260 if (rc) {
1261 printk(llc_sysctl_err_msg);
1262 goto out_proc;
1263 }
1264 rc = sock_register(fam: &llc_ui_family_ops);
1265 if (rc) {
1266 printk(llc_sock_err_msg);
1267 goto out_sysctl;
1268 }
1269 llc_add_pack(LLC_DEST_SAP, handler: llc_sap_handler);
1270 llc_add_pack(LLC_DEST_CONN, handler: llc_conn_handler);
1271out:
1272 return rc;
1273out_sysctl:
1274 llc_sysctl_exit();
1275out_proc:
1276 llc_proc_exit();
1277out_station:
1278 llc_station_exit();
1279 proto_unregister(prot: &llc_proto);
1280 goto out;
1281}
1282
1283static void __exit llc2_exit(void)
1284{
1285 llc_station_exit();
1286 llc_remove_pack(LLC_DEST_SAP);
1287 llc_remove_pack(LLC_DEST_CONN);
1288 sock_unregister(PF_LLC);
1289 llc_proc_exit();
1290 llc_sysctl_exit();
1291 proto_unregister(prot: &llc_proto);
1292}
1293
1294module_init(llc2_init);
1295module_exit(llc2_exit);
1296
1297MODULE_LICENSE("GPL");
1298MODULE_AUTHOR("Procom 1997, Jay Schullist 2001, Arnaldo C. Melo 2001-2003");
1299MODULE_DESCRIPTION("IEEE 802.2 PF_LLC support");
1300MODULE_ALIAS_NETPROTO(PF_LLC);
1301

source code of linux/net/llc/af_llc.c