forked from torvalds/linux
-
Notifications
You must be signed in to change notification settings - Fork 17
/
af_llc.c
1272 lines (1175 loc) · 31.3 KB
/
af_llc.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/*
* af_llc.c - LLC User Interface SAPs
* Description:
* Functions in this module are implementation of socket based llc
* communications for the Linux operating system. Support of llc class
* one and class two is provided via SOCK_DGRAM and SOCK_STREAM
* respectively.
*
* An llc2 connection is (mac + sap), only one llc2 sap connection
* is allowed per mac. Though one sap may have multiple mac + sap
* connections.
*
* Copyright (c) 2001 by Jay Schulist <[email protected]>
* 2002-2003 by Arnaldo Carvalho de Melo <[email protected]>
*
* This program can be redistributed or modified under the terms of the
* GNU General Public License as published by the Free Software Foundation.
* This program is distributed without any warranty or implied warranty
* of merchantability or fitness for a particular purpose.
*
* See the GNU General Public License for more details.
*/
#include <linux/compiler.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/rtnetlink.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/sched/signal.h>
#include <net/llc.h>
#include <net/llc_sap.h>
#include <net/llc_pdu.h>
#include <net/llc_conn.h>
#include <net/tcp_states.h>
/* remember: uninitialized global data is zeroed because its in .bss */
static u16 llc_ui_sap_last_autoport = LLC_SAP_DYN_START;
static u16 llc_ui_sap_link_no_max[256];
static struct sockaddr_llc llc_ui_addrnull;
static const struct proto_ops llc_ui_ops;
static bool llc_ui_wait_for_conn(struct sock *sk, long timeout);
static int llc_ui_wait_for_disc(struct sock *sk, long timeout);
static int llc_ui_wait_for_busy_core(struct sock *sk, long timeout);
#if 0
#define dprintk(args...) printk(KERN_DEBUG args)
#else
#define dprintk(args...)
#endif
/* Maybe we'll add some more in the future. */
#define LLC_CMSG_PKTINFO 1
/**
* llc_ui_next_link_no - return the next unused link number for a sap
* @sap: Address of sap to get link number from.
*
* Return the next unused link number for a given sap.
*/
static inline u16 llc_ui_next_link_no(int sap)
{
return llc_ui_sap_link_no_max[sap]++;
}
/**
* llc_proto_type - return eth protocol for ARP header type
* @arphrd: ARP header type.
*
* Given an ARP header type return the corresponding ethernet protocol.
*/
static inline __be16 llc_proto_type(u16 arphrd)
{
return htons(ETH_P_802_2);
}
/**
* llc_ui_addr_null - determines if a address structure is null
* @addr: Address to test if null.
*/
static inline u8 llc_ui_addr_null(struct sockaddr_llc *addr)
{
return !memcmp(addr, &llc_ui_addrnull, sizeof(*addr));
}
/**
* llc_ui_header_len - return length of llc header based on operation
* @sk: Socket which contains a valid llc socket type.
* @addr: Complete sockaddr_llc structure received from the user.
*
* Provide the length of the llc header depending on what kind of
* operation the user would like to perform and the type of socket.
* Returns the correct llc header length.
*/
static inline u8 llc_ui_header_len(struct sock *sk, struct sockaddr_llc *addr)
{
u8 rc = LLC_PDU_LEN_U;
if (addr->sllc_test || addr->sllc_xid)
rc = LLC_PDU_LEN_U;
else if (sk->sk_type == SOCK_STREAM)
rc = LLC_PDU_LEN_I;
return rc;
}
/**
* llc_ui_send_data - send data via reliable llc2 connection
* @sk: Connection the socket is using.
* @skb: Data the user wishes to send.
* @noblock: can we block waiting for data?
*
* Send data via reliable llc2 connection.
* Returns 0 upon success, non-zero if action did not succeed.
*
* This function always consumes a reference to the skb.
*/
static int llc_ui_send_data(struct sock* sk, struct sk_buff *skb, int noblock)
{
struct llc_sock* llc = llc_sk(sk);
if (unlikely(llc_data_accept_state(llc->state) ||
llc->remote_busy_flag ||
llc->p_flag)) {
long timeout = sock_sndtimeo(sk, noblock);
int rc;
rc = llc_ui_wait_for_busy_core(sk, timeout);
if (rc) {
kfree_skb(skb);
return rc;
}
}
return llc_build_and_send_pkt(sk, skb);
}
static void llc_ui_sk_init(struct socket *sock, struct sock *sk)
{
sock_graft(sk, sock);
sk->sk_type = sock->type;
sock->ops = &llc_ui_ops;
}
static struct proto llc_proto = {
.name = "LLC",
.owner = THIS_MODULE,
.obj_size = sizeof(struct llc_sock),
.slab_flags = SLAB_TYPESAFE_BY_RCU,
};
/**
* llc_ui_create - alloc and init a new llc_ui socket
* @net: network namespace (must be default network)
* @sock: Socket to initialize and attach allocated sk to.
* @protocol: Unused.
* @kern: on behalf of kernel or userspace
*
* Allocate and initialize a new llc_ui socket, validate the user wants a
* socket type we have available.
* Returns 0 upon success, negative upon failure.
*/
static int llc_ui_create(struct net *net, struct socket *sock, int protocol,
int kern)
{
struct sock *sk;
int rc = -ESOCKTNOSUPPORT;
if (!ns_capable(net->user_ns, CAP_NET_RAW))
return -EPERM;
if (!net_eq(net, &init_net))
return -EAFNOSUPPORT;
if (likely(sock->type == SOCK_DGRAM || sock->type == SOCK_STREAM)) {
rc = -ENOMEM;
sk = llc_sk_alloc(net, PF_LLC, GFP_KERNEL, &llc_proto, kern);
if (sk) {
rc = 0;
llc_ui_sk_init(sock, sk);
}
}
return rc;
}
/**
* llc_ui_release - shutdown socket
* @sock: Socket to release.
*
* Shutdown and deallocate an existing socket.
*/
static int llc_ui_release(struct socket *sock)
{
struct sock *sk = sock->sk;
struct llc_sock *llc;
if (unlikely(sk == NULL))
goto out;
sock_hold(sk);
lock_sock(sk);
llc = llc_sk(sk);
dprintk("%s: closing local(%02X) remote(%02X)\n", __func__,
llc->laddr.lsap, llc->daddr.lsap);
if (!llc_send_disc(sk))
llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo);
if (!sock_flag(sk, SOCK_ZAPPED)) {
struct llc_sap *sap = llc->sap;
/* Hold this for release_sock(), so that llc_backlog_rcv()
* could still use it.
*/
llc_sap_hold(sap);
llc_sap_remove_socket(llc->sap, sk);
release_sock(sk);
llc_sap_put(sap);
} else {
release_sock(sk);
}
if (llc->dev)
dev_put(llc->dev);
sock_put(sk);
llc_sk_free(sk);
out:
return 0;
}
/**
* llc_ui_autoport - provide dynamically allocate SAP number
*
* Provide the caller with a dynamically allocated SAP number according
* to the rules that are set in this function. Returns: 0, upon failure,
* SAP number otherwise.
*/
static int llc_ui_autoport(void)
{
struct llc_sap *sap;
int i, tries = 0;
while (tries < LLC_SAP_DYN_TRIES) {
for (i = llc_ui_sap_last_autoport;
i < LLC_SAP_DYN_STOP; i += 2) {
sap = llc_sap_find(i);
if (!sap) {
llc_ui_sap_last_autoport = i + 2;
goto out;
}
llc_sap_put(sap);
}
llc_ui_sap_last_autoport = LLC_SAP_DYN_START;
tries++;
}
i = 0;
out:
return i;
}
/**
* llc_ui_autobind - automatically bind a socket to a sap
* @sock: socket to bind
* @addr: address to connect to
*
* Used by llc_ui_connect and llc_ui_sendmsg when the user hasn't
* specifically used llc_ui_bind to bind to an specific address/sap
*
* Returns: 0 upon success, negative otherwise.
*/
static int llc_ui_autobind(struct socket *sock, struct sockaddr_llc *addr)
{
struct sock *sk = sock->sk;
struct llc_sock *llc = llc_sk(sk);
struct llc_sap *sap;
int rc = -EINVAL;
if (!sock_flag(sk, SOCK_ZAPPED))
goto out;
rc = -ENODEV;
if (sk->sk_bound_dev_if) {
llc->dev = dev_get_by_index(&init_net, sk->sk_bound_dev_if);
if (llc->dev && addr->sllc_arphrd != llc->dev->type) {
dev_put(llc->dev);
llc->dev = NULL;
}
} else
llc->dev = dev_getfirstbyhwtype(&init_net, addr->sllc_arphrd);
if (!llc->dev)
goto out;
rc = -EUSERS;
llc->laddr.lsap = llc_ui_autoport();
if (!llc->laddr.lsap)
goto out;
rc = -EBUSY; /* some other network layer is using the sap */
sap = llc_sap_open(llc->laddr.lsap, NULL);
if (!sap)
goto out;
memcpy(llc->laddr.mac, llc->dev->dev_addr, IFHWADDRLEN);
memcpy(&llc->addr, addr, sizeof(llc->addr));
/* assign new connection to its SAP */
llc_sap_add_socket(sap, sk);
sock_reset_flag(sk, SOCK_ZAPPED);
rc = 0;
out:
return rc;
}
/**
* llc_ui_bind - bind a socket to a specific address.
* @sock: Socket to bind an address to.
* @uaddr: Address the user wants the socket bound to.
* @addrlen: Length of the uaddr structure.
*
* Bind a socket to a specific address. For llc a user is able to bind to
* a specific sap only or mac + sap.
* If the user desires to bind to a specific mac + sap, it is possible to
* have multiple sap connections via multiple macs.
* Bind and autobind for that matter must enforce the correct sap usage
* otherwise all hell will break loose.
* Returns: 0 upon success, negative otherwise.
*/
static int llc_ui_bind(struct socket *sock, struct sockaddr *uaddr, int addrlen)
{
struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr;
struct sock *sk = sock->sk;
struct llc_sock *llc = llc_sk(sk);
struct llc_sap *sap;
int rc = -EINVAL;
lock_sock(sk);
if (unlikely(!sock_flag(sk, SOCK_ZAPPED) || addrlen != sizeof(*addr)))
goto out;
rc = -EAFNOSUPPORT;
if (unlikely(addr->sllc_family != AF_LLC))
goto out;
dprintk("%s: binding %02X\n", __func__, addr->sllc_sap);
rc = -ENODEV;
rcu_read_lock();
if (sk->sk_bound_dev_if) {
llc->dev = dev_get_by_index_rcu(&init_net, sk->sk_bound_dev_if);
if (llc->dev) {
if (!addr->sllc_arphrd)
addr->sllc_arphrd = llc->dev->type;
if (is_zero_ether_addr(addr->sllc_mac))
memcpy(addr->sllc_mac, llc->dev->dev_addr,
IFHWADDRLEN);
if (addr->sllc_arphrd != llc->dev->type ||
!ether_addr_equal(addr->sllc_mac,
llc->dev->dev_addr)) {
rc = -EINVAL;
llc->dev = NULL;
}
}
} else
llc->dev = dev_getbyhwaddr_rcu(&init_net, addr->sllc_arphrd,
addr->sllc_mac);
if (llc->dev)
dev_hold(llc->dev);
rcu_read_unlock();
if (!llc->dev)
goto out;
if (!addr->sllc_sap) {
rc = -EUSERS;
addr->sllc_sap = llc_ui_autoport();
if (!addr->sllc_sap)
goto out;
}
sap = llc_sap_find(addr->sllc_sap);
if (!sap) {
sap = llc_sap_open(addr->sllc_sap, NULL);
rc = -EBUSY; /* some other network layer is using the sap */
if (!sap)
goto out;
} else {
struct llc_addr laddr, daddr;
struct sock *ask;
memset(&laddr, 0, sizeof(laddr));
memset(&daddr, 0, sizeof(daddr));
/*
* FIXME: check if the address is multicast,
* only SOCK_DGRAM can do this.
*/
memcpy(laddr.mac, addr->sllc_mac, IFHWADDRLEN);
laddr.lsap = addr->sllc_sap;
rc = -EADDRINUSE; /* mac + sap clash. */
ask = llc_lookup_established(sap, &daddr, &laddr);
if (ask) {
sock_put(ask);
goto out_put;
}
}
llc->laddr.lsap = addr->sllc_sap;
memcpy(llc->laddr.mac, addr->sllc_mac, IFHWADDRLEN);
memcpy(&llc->addr, addr, sizeof(llc->addr));
/* assign new connection to its SAP */
llc_sap_add_socket(sap, sk);
sock_reset_flag(sk, SOCK_ZAPPED);
rc = 0;
out_put:
llc_sap_put(sap);
out:
release_sock(sk);
return rc;
}
/**
* llc_ui_shutdown - shutdown a connect llc2 socket.
* @sock: Socket to shutdown.
* @how: What part of the socket to shutdown.
*
* Shutdown a connected llc2 socket. Currently this function only supports
* shutting down both sends and receives (2), we could probably make this
* function such that a user can shutdown only half the connection but not
* right now.
* Returns: 0 upon success, negative otherwise.
*/
static int llc_ui_shutdown(struct socket *sock, int how)
{
struct sock *sk = sock->sk;
int rc = -ENOTCONN;
lock_sock(sk);
if (unlikely(sk->sk_state != TCP_ESTABLISHED))
goto out;
rc = -EINVAL;
if (how != 2)
goto out;
rc = llc_send_disc(sk);
if (!rc)
rc = llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo);
/* Wake up anyone sleeping in poll */
sk->sk_state_change(sk);
out:
release_sock(sk);
return rc;
}
/**
* llc_ui_connect - Connect to a remote llc2 mac + sap.
* @sock: Socket which will be connected to the remote destination.
* @uaddr: Remote and possibly the local address of the new connection.
* @addrlen: Size of uaddr structure.
* @flags: Operational flags specified by the user.
*
* Connect to a remote llc2 mac + sap. The caller must specify the
* destination mac and address to connect to. If the user hasn't previously
* called bind(2) with a smac the address of the first interface of the
* specified arp type will be used.
* This function will autobind if user did not previously call bind.
* Returns: 0 upon success, negative otherwise.
*/
static int llc_ui_connect(struct socket *sock, struct sockaddr *uaddr,
int addrlen, int flags)
{
struct sock *sk = sock->sk;
struct llc_sock *llc = llc_sk(sk);
struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr;
int rc = -EINVAL;
lock_sock(sk);
if (unlikely(addrlen != sizeof(*addr)))
goto out;
rc = -EAFNOSUPPORT;
if (unlikely(addr->sllc_family != AF_LLC))
goto out;
if (unlikely(sk->sk_type != SOCK_STREAM))
goto out;
rc = -EALREADY;
if (unlikely(sock->state == SS_CONNECTING))
goto out;
/* bind connection to sap if user hasn't done it. */
if (sock_flag(sk, SOCK_ZAPPED)) {
/* bind to sap with null dev, exclusive */
rc = llc_ui_autobind(sock, addr);
if (rc)
goto out;
}
llc->daddr.lsap = addr->sllc_sap;
memcpy(llc->daddr.mac, addr->sllc_mac, IFHWADDRLEN);
sock->state = SS_CONNECTING;
sk->sk_state = TCP_SYN_SENT;
llc->link = llc_ui_next_link_no(llc->sap->laddr.lsap);
rc = llc_establish_connection(sk, llc->dev->dev_addr,
addr->sllc_mac, addr->sllc_sap);
if (rc) {
dprintk("%s: llc_ui_send_conn failed :-(\n", __func__);
sock->state = SS_UNCONNECTED;
sk->sk_state = TCP_CLOSE;
goto out;
}
if (sk->sk_state == TCP_SYN_SENT) {
const long timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
if (!timeo || !llc_ui_wait_for_conn(sk, timeo))
goto out;
rc = sock_intr_errno(timeo);
if (signal_pending(current))
goto out;
}
if (sk->sk_state == TCP_CLOSE)
goto sock_error;
sock->state = SS_CONNECTED;
rc = 0;
out:
release_sock(sk);
return rc;
sock_error:
rc = sock_error(sk) ? : -ECONNABORTED;
sock->state = SS_UNCONNECTED;
goto out;
}
/**
* llc_ui_listen - allow a normal socket to accept incoming connections
* @sock: Socket to allow incoming connections on.
* @backlog: Number of connections to queue.
*
* Allow a normal socket to accept incoming connections.
* Returns 0 upon success, negative otherwise.
*/
static int llc_ui_listen(struct socket *sock, int backlog)
{
struct sock *sk = sock->sk;
int rc = -EINVAL;
lock_sock(sk);
if (unlikely(sock->state != SS_UNCONNECTED))
goto out;
rc = -EOPNOTSUPP;
if (unlikely(sk->sk_type != SOCK_STREAM))
goto out;
rc = -EAGAIN;
if (sock_flag(sk, SOCK_ZAPPED))
goto out;
rc = 0;
if (!(unsigned int)backlog) /* BSDism */
backlog = 1;
sk->sk_max_ack_backlog = backlog;
if (sk->sk_state != TCP_LISTEN) {
sk->sk_ack_backlog = 0;
sk->sk_state = TCP_LISTEN;
}
sk->sk_socket->flags |= __SO_ACCEPTCON;
out:
release_sock(sk);
return rc;
}
static int llc_ui_wait_for_disc(struct sock *sk, long timeout)
{
DEFINE_WAIT_FUNC(wait, woken_wake_function);
int rc = 0;
add_wait_queue(sk_sleep(sk), &wait);
while (1) {
if (sk_wait_event(sk, &timeout, sk->sk_state == TCP_CLOSE, &wait))
break;
rc = -ERESTARTSYS;
if (signal_pending(current))
break;
rc = -EAGAIN;
if (!timeout)
break;
rc = 0;
}
remove_wait_queue(sk_sleep(sk), &wait);
return rc;
}
static bool llc_ui_wait_for_conn(struct sock *sk, long timeout)
{
DEFINE_WAIT_FUNC(wait, woken_wake_function);
add_wait_queue(sk_sleep(sk), &wait);
while (1) {
if (sk_wait_event(sk, &timeout, sk->sk_state != TCP_SYN_SENT, &wait))
break;
if (signal_pending(current) || !timeout)
break;
}
remove_wait_queue(sk_sleep(sk), &wait);
return timeout;
}
static int llc_ui_wait_for_busy_core(struct sock *sk, long timeout)
{
DEFINE_WAIT_FUNC(wait, woken_wake_function);
struct llc_sock *llc = llc_sk(sk);
int rc;
add_wait_queue(sk_sleep(sk), &wait);
while (1) {
rc = 0;
if (sk_wait_event(sk, &timeout,
(sk->sk_shutdown & RCV_SHUTDOWN) ||
(!llc_data_accept_state(llc->state) &&
!llc->remote_busy_flag &&
!llc->p_flag), &wait))
break;
rc = -ERESTARTSYS;
if (signal_pending(current))
break;
rc = -EAGAIN;
if (!timeout)
break;
}
remove_wait_queue(sk_sleep(sk), &wait);
return rc;
}
static int llc_wait_data(struct sock *sk, long timeo)
{
int rc;
while (1) {
/*
* POSIX 1003.1g mandates this order.
*/
rc = sock_error(sk);
if (rc)
break;
rc = 0;
if (sk->sk_shutdown & RCV_SHUTDOWN)
break;
rc = -EAGAIN;
if (!timeo)
break;
rc = sock_intr_errno(timeo);
if (signal_pending(current))
break;
rc = 0;
if (sk_wait_data(sk, &timeo, NULL))
break;
}
return rc;
}
static void llc_cmsg_rcv(struct msghdr *msg, struct sk_buff *skb)
{
struct llc_sock *llc = llc_sk(skb->sk);
if (llc->cmsg_flags & LLC_CMSG_PKTINFO) {
struct llc_pktinfo info;
memset(&info, 0, sizeof(info));
info.lpi_ifindex = llc_sk(skb->sk)->dev->ifindex;
llc_pdu_decode_dsap(skb, &info.lpi_sap);
llc_pdu_decode_da(skb, info.lpi_mac);
put_cmsg(msg, SOL_LLC, LLC_OPT_PKTINFO, sizeof(info), &info);
}
}
/**
* llc_ui_accept - accept a new incoming connection.
* @sock: Socket which connections arrive on.
* @newsock: Socket to move incoming connection to.
* @flags: User specified operational flags.
* @kern: If the socket is kernel internal
*
* Accept a new incoming connection.
* Returns 0 upon success, negative otherwise.
*/
static int llc_ui_accept(struct socket *sock, struct socket *newsock, int flags,
bool kern)
{
struct sock *sk = sock->sk, *newsk;
struct llc_sock *llc, *newllc;
struct sk_buff *skb;
int rc = -EOPNOTSUPP;
dprintk("%s: accepting on %02X\n", __func__,
llc_sk(sk)->laddr.lsap);
lock_sock(sk);
if (unlikely(sk->sk_type != SOCK_STREAM))
goto out;
rc = -EINVAL;
if (unlikely(sock->state != SS_UNCONNECTED ||
sk->sk_state != TCP_LISTEN))
goto out;
/* wait for a connection to arrive. */
if (skb_queue_empty(&sk->sk_receive_queue)) {
rc = llc_wait_data(sk, sk->sk_rcvtimeo);
if (rc)
goto out;
}
dprintk("%s: got a new connection on %02X\n", __func__,
llc_sk(sk)->laddr.lsap);
skb = skb_dequeue(&sk->sk_receive_queue);
rc = -EINVAL;
if (!skb->sk)
goto frees;
rc = 0;
newsk = skb->sk;
/* attach connection to a new socket. */
llc_ui_sk_init(newsock, newsk);
sock_reset_flag(newsk, SOCK_ZAPPED);
newsk->sk_state = TCP_ESTABLISHED;
newsock->state = SS_CONNECTED;
llc = llc_sk(sk);
newllc = llc_sk(newsk);
memcpy(&newllc->addr, &llc->addr, sizeof(newllc->addr));
newllc->link = llc_ui_next_link_no(newllc->laddr.lsap);
/* put original socket back into a clean listen state. */
sk->sk_state = TCP_LISTEN;
sk_acceptq_removed(sk);
dprintk("%s: ok success on %02X, client on %02X\n", __func__,
llc_sk(sk)->addr.sllc_sap, newllc->daddr.lsap);
frees:
kfree_skb(skb);
out:
release_sock(sk);
return rc;
}
/**
* llc_ui_recvmsg - copy received data to the socket user.
* @sock: Socket to copy data from.
* @msg: Various user space related information.
* @len: Size of user buffer.
* @flags: User specified flags.
*
* Copy received data to the socket user.
* Returns non-negative upon success, negative otherwise.
*/
static int llc_ui_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
int flags)
{
DECLARE_SOCKADDR(struct sockaddr_llc *, uaddr, msg->msg_name);
const int nonblock = flags & MSG_DONTWAIT;
struct sk_buff *skb = NULL;
struct sock *sk = sock->sk;
struct llc_sock *llc = llc_sk(sk);
size_t copied = 0;
u32 peek_seq = 0;
u32 *seq, skb_len;
unsigned long used;
int target; /* Read at least this many bytes */
long timeo;
lock_sock(sk);
copied = -ENOTCONN;
if (unlikely(sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_LISTEN))
goto out;
timeo = sock_rcvtimeo(sk, nonblock);
seq = &llc->copied_seq;
if (flags & MSG_PEEK) {
peek_seq = llc->copied_seq;
seq = &peek_seq;
}
target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
copied = 0;
do {
u32 offset;
/*
* We need to check signals first, to get correct SIGURG
* handling. FIXME: Need to check this doesn't impact 1003.1g
* and move it down to the bottom of the loop
*/
if (signal_pending(current)) {
if (copied)
break;
copied = timeo ? sock_intr_errno(timeo) : -EAGAIN;
break;
}
/* Next get a buffer. */
skb = skb_peek(&sk->sk_receive_queue);
if (skb) {
offset = *seq;
goto found_ok_skb;
}
/* Well, if we have backlog, try to process it now yet. */
if (copied >= target && !READ_ONCE(sk->sk_backlog.tail))
break;
if (copied) {
if (sk->sk_err ||
sk->sk_state == TCP_CLOSE ||
(sk->sk_shutdown & RCV_SHUTDOWN) ||
!timeo ||
(flags & MSG_PEEK))
break;
} else {
if (sock_flag(sk, SOCK_DONE))
break;
if (sk->sk_err) {
copied = sock_error(sk);
break;
}
if (sk->sk_shutdown & RCV_SHUTDOWN)
break;
if (sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_CLOSE) {
if (!sock_flag(sk, SOCK_DONE)) {
/*
* This occurs when user tries to read
* from never connected socket.
*/
copied = -ENOTCONN;
break;
}
break;
}
if (!timeo) {
copied = -EAGAIN;
break;
}
}
if (copied >= target) { /* Do not sleep, just process backlog. */
release_sock(sk);
lock_sock(sk);
} else
sk_wait_data(sk, &timeo, NULL);
if ((flags & MSG_PEEK) && peek_seq != llc->copied_seq) {
net_dbg_ratelimited("LLC(%s:%d): Application bug, race in MSG_PEEK\n",
current->comm,
task_pid_nr(current));
peek_seq = llc->copied_seq;
}
continue;
found_ok_skb:
skb_len = skb->len;
/* Ok so how much can we use? */
used = skb->len - offset;
if (len < used)
used = len;
if (!(flags & MSG_TRUNC)) {
int rc = skb_copy_datagram_msg(skb, offset, msg, used);
if (rc) {
/* Exception. Bailout! */
if (!copied)
copied = -EFAULT;
break;
}
}
*seq += used;
copied += used;
len -= used;
/* For non stream protcols we get one packet per recvmsg call */
if (sk->sk_type != SOCK_STREAM)
goto copy_uaddr;
if (!(flags & MSG_PEEK)) {
skb_unlink(skb, &sk->sk_receive_queue);
kfree_skb(skb);
*seq = 0;
}
/* Partial read */
if (used + offset < skb_len)
continue;
} while (len > 0);
out:
release_sock(sk);
return copied;
copy_uaddr:
if (uaddr != NULL && skb != NULL) {
memcpy(uaddr, llc_ui_skb_cb(skb), sizeof(*uaddr));
msg->msg_namelen = sizeof(*uaddr);
}
if (llc_sk(sk)->cmsg_flags)
llc_cmsg_rcv(msg, skb);
if (!(flags & MSG_PEEK)) {
skb_unlink(skb, &sk->sk_receive_queue);
kfree_skb(skb);
*seq = 0;
}
goto out;
}
/**
* llc_ui_sendmsg - Transmit data provided by the socket user.
* @sock: Socket to transmit data from.
* @msg: Various user related information.
* @len: Length of data to transmit.
*
* Transmit data provided by the socket user.
* Returns non-negative upon success, negative otherwise.
*/
static int llc_ui_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
{
struct sock *sk = sock->sk;
struct llc_sock *llc = llc_sk(sk);
DECLARE_SOCKADDR(struct sockaddr_llc *, addr, msg->msg_name);
int flags = msg->msg_flags;
int noblock = flags & MSG_DONTWAIT;
struct sk_buff *skb = NULL;
size_t size = 0;
int rc = -EINVAL, copied = 0, hdrlen;
dprintk("%s: sending from %02X to %02X\n", __func__,
llc->laddr.lsap, llc->daddr.lsap);
lock_sock(sk);
if (addr) {
if (msg->msg_namelen < sizeof(*addr))
goto out;
} else {
if (llc_ui_addr_null(&llc->addr))
goto out;
addr = &llc->addr;
}
/* must bind connection to sap if user hasn't done it. */
if (sock_flag(sk, SOCK_ZAPPED)) {
/* bind to sap with null dev, exclusive. */
rc = llc_ui_autobind(sock, addr);
if (rc)
goto out;
}
hdrlen = llc->dev->hard_header_len + llc_ui_header_len(sk, addr);
size = hdrlen + len;
if (size > llc->dev->mtu)
size = llc->dev->mtu;
copied = size - hdrlen;
rc = -EINVAL;
if (copied < 0)
goto out;
release_sock(sk);
skb = sock_alloc_send_skb(sk, size, noblock, &rc);
lock_sock(sk);
if (!skb)
goto out;
skb->dev = llc->dev;
skb->protocol = llc_proto_type(addr->sllc_arphrd);
skb_reserve(skb, hdrlen);
rc = memcpy_from_msg(skb_put(skb, copied), msg, copied);
if (rc)
goto out;
if (sk->sk_type == SOCK_DGRAM || addr->sllc_ua) {
llc_build_and_send_ui_pkt(llc->sap, skb, addr->sllc_mac,
addr->sllc_sap);
skb = NULL;
goto out;
}
if (addr->sllc_test) {
llc_build_and_send_test_pkt(llc->sap, skb, addr->sllc_mac,
addr->sllc_sap);
skb = NULL;
goto out;
}
if (addr->sllc_xid) {
llc_build_and_send_xid_pkt(llc->sap, skb, addr->sllc_mac,
addr->sllc_sap);
skb = NULL;
goto out;
}
rc = -ENOPROTOOPT;
if (!(sk->sk_type == SOCK_STREAM && !addr->sllc_ua))
goto out;
rc = llc_ui_send_data(sk, skb, noblock);
skb = NULL;
out:
kfree_skb(skb);
if (rc)
dprintk("%s: failed sending from %02X to %02X: %d\n",
__func__, llc->laddr.lsap, llc->daddr.lsap, rc);
release_sock(sk);
return rc ? : copied;
}
/**
* llc_ui_getname - return the address info of a socket
* @sock: Socket to get address of.
* @uaddr: Address structure to return information.
* @uaddrlen: Length of address structure.
* @peer: Does user want local or remote address information.
*
* Return the address information of a socket.
*/
static int llc_ui_getname(struct socket *sock, struct sockaddr *uaddr,
int peer)
{
struct sockaddr_llc sllc;
struct sock *sk = sock->sk;
struct llc_sock *llc = llc_sk(sk);
int rc = -EBADF;
memset(&sllc, 0, sizeof(sllc));
lock_sock(sk);
if (sock_flag(sk, SOCK_ZAPPED))
goto out;
if (peer) {