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
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
|
/* $OpenBSD: bpf.c,v 1.30 2001/10/02 18:04:35 deraadt Exp $ */
/* $NetBSD: bpf.c,v 1.33 1997/02/21 23:59:35 thorpej Exp $ */
/*
* Copyright (c) 1990, 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from the Stanford/CMU enet packet filter,
* (net/enet.c) distributed as part of 4.3BSD, and code contributed
* to Berkeley by Steven McCanne and Van Jacobson both of Lawrence
* Berkeley Laboratory.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)bpf.c 8.2 (Berkeley) 3/28/94
*/
#include "bpfilter.h"
#include <sys/param.h>
#include <sys/mbuf.h>
#include <sys/proc.h>
#include <sys/signalvar.h>
#include <sys/ioctl.h>
#include <sys/conf.h>
#include <sys/vnode.h>
#include <sys/file.h>
#include <sys/socket.h>
#include <sys/kernel.h>
#include <net/if.h>
#include <net/bpf.h>
#include <net/bpfdesc.h>
#include <netinet/in.h>
#include <netinet/if_arc.h>
#include <netinet/if_ether.h>
#define BPF_BUFSIZE 8192 /* 4096 too small for FDDI frames */
#define PRINET 26 /* interruptible */
/*
* The default read buffer size is patchable.
*/
int bpf_bufsize = BPF_BUFSIZE;
/*
* bpf_iflist is the list of interfaces; each corresponds to an ifnet
* bpf_dtab holds the descriptors, indexed by minor device #
*/
struct bpf_if *bpf_iflist;
struct bpf_d *bpf_dtab;
int nbpfilter;
int bpf_allocbufs __P((struct bpf_d *));
void bpf_freed __P((struct bpf_d *));
void bpf_ifname __P((struct ifnet *, struct ifreq *));
void bpf_mcopy __P((const void *, void *, size_t));
int bpf_movein __P((struct uio *, int, struct mbuf **, struct sockaddr *));
void bpf_attachd __P((struct bpf_d *, struct bpf_if *));
void bpf_detachd __P((struct bpf_d *));
int bpf_setif __P((struct bpf_d *, struct ifreq *));
int bpfselect __P((dev_t, int, struct proc *));
static __inline void bpf_wakeup __P((struct bpf_d *));
void bpf_catchpacket __P((struct bpf_d *, u_char *, size_t, size_t,
void (*)(const void *, void *, size_t)));
void bpf_reset_d __P((struct bpf_d *));
int
bpf_movein(uio, linktype, mp, sockp)
register struct uio *uio;
int linktype;
register struct mbuf **mp;
register struct sockaddr *sockp;
{
struct mbuf *m;
int error;
int len;
int hlen;
/*
* Build a sockaddr based on the data link layer type.
* We do this at this level because the ethernet header
* is copied directly into the data field of the sockaddr.
* In the case of SLIP, there is no header and the packet
* is forwarded as is.
* Also, we are careful to leave room at the front of the mbuf
* for the link level header.
*/
switch (linktype) {
case DLT_SLIP:
sockp->sa_family = AF_INET;
hlen = 0;
break;
case DLT_PPP:
sockp->sa_family = AF_UNSPEC;
hlen = 0;
break;
case DLT_EN10MB:
sockp->sa_family = AF_UNSPEC;
/* XXX Would MAXLINKHDR be better? */
hlen = sizeof(struct ether_header);
break;
case DLT_ARCNET:
sockp->sa_family = AF_UNSPEC;
hlen = ARC_HDRLEN;
break;
case DLT_FDDI:
sockp->sa_family = AF_UNSPEC;
/* XXX 4(FORMAC)+6(dst)+6(src)+3(LLC)+5(SNAP) */
hlen = 24;
break;
case DLT_RAW:
case DLT_NULL:
sockp->sa_family = AF_UNSPEC;
hlen = 0;
break;
default:
return (EIO);
}
len = uio->uio_resid;
if ((unsigned)len > MCLBYTES)
return (EIO);
MGETHDR(m, M_WAIT, MT_DATA);
m->m_pkthdr.rcvif = 0;
m->m_pkthdr.len = len - hlen;
if (len > MHLEN) {
MCLGET(m, M_WAIT);
if ((m->m_flags & M_EXT) == 0) {
error = ENOBUFS;
goto bad;
}
}
m->m_len = len;
*mp = m;
/*
* Make room for link header.
*/
if (hlen != 0) {
m->m_len -= hlen;
m->m_data += hlen; /* XXX */
error = uiomove((caddr_t)sockp->sa_data, hlen, uio);
if (error)
goto bad;
}
error = uiomove(mtod(m, caddr_t), len - hlen, uio);
if (!error)
return (0);
bad:
m_freem(m);
return (error);
}
/*
* Attach file to the bpf interface, i.e. make d listen on bp.
* Must be called at splimp.
*/
void
bpf_attachd(d, bp)
struct bpf_d *d;
struct bpf_if *bp;
{
/*
* Point d at bp, and add d to the interface's list of listeners.
* Finally, point the driver's bpf cookie at the interface so
* it will divert packets to bpf.
*/
d->bd_bif = bp;
d->bd_next = bp->bif_dlist;
bp->bif_dlist = d;
*bp->bif_driverp = bp;
}
/*
* Detach a file from its interface.
*/
void
bpf_detachd(d)
struct bpf_d *d;
{
struct bpf_d **p;
struct bpf_if *bp;
bp = d->bd_bif;
/*
* Check if this descriptor had requested promiscuous mode.
* If so, turn it off.
*/
if (d->bd_promisc) {
int error;
d->bd_promisc = 0;
error = ifpromisc(bp->bif_ifp, 0);
if (error && !(error == EINVAL || error == ENODEV))
/*
* Something is really wrong if we were able to put
* the driver into promiscuous mode, but can't
* take it out.
*/
panic("bpf: ifpromisc failed");
}
/* Remove d from the interface's descriptor list. */
p = &bp->bif_dlist;
while (*p != d) {
p = &(*p)->bd_next;
if (*p == 0)
panic("bpf_detachd: descriptor not in list");
}
*p = (*p)->bd_next;
if (bp->bif_dlist == 0)
/*
* Let the driver know that there are no more listeners.
*/
*d->bd_bif->bif_driverp = 0;
d->bd_bif = 0;
}
/*
* Mark a descriptor free by making it point to itself.
* This is probably cheaper than marking with a constant since
* the address should be in a register anyway.
*/
#define D_ISFREE(d) ((d) == (d)->bd_next)
#define D_MARKFREE(d) ((d)->bd_next = (d))
#define D_MARKUSED(d) ((d)->bd_next = 0)
/*
* bpfilterattach() is called at boot time in new systems. We do
* nothing here since old systems will not call this.
*/
/* ARGSUSED */
void
bpfilterattach(n)
int n;
{
int i;
bpf_dtab = malloc(n * sizeof(*bpf_dtab), M_DEVBUF, M_NOWAIT);
if (!bpf_dtab)
return;
nbpfilter = n;
bzero(bpf_dtab, n * sizeof(*bpf_dtab));
/*
* Mark all the descriptors free if this hasn't been done.
*/
if (!D_ISFREE(&bpf_dtab[0]))
for (i = 0; i < nbpfilter; ++i)
D_MARKFREE(&bpf_dtab[i]);
}
/*
* Open ethernet device. Returns ENXIO for illegal minor device number,
* EBUSY if file is open by another process.
*/
/* ARGSUSED */
int
bpfopen(dev, flag, mode, p)
dev_t dev;
int flag;
int mode;
struct proc *p;
{
register struct bpf_d *d;
if (minor(dev) >= nbpfilter)
return (ENXIO);
/*
* Each minor can be opened by only one process. If the requested
* minor is in use, return EBUSY.
*/
d = &bpf_dtab[minor(dev)];
if (!D_ISFREE(d))
return (EBUSY);
/* Mark "free" and do most initialization. */
bzero((char *)d, sizeof(*d));
d->bd_bufsize = bpf_bufsize;
d->bd_sig = SIGIO;
return (0);
}
/*
* Close the descriptor by detaching it from its interface,
* deallocating its buffers, and marking it free.
*/
/* ARGSUSED */
int
bpfclose(dev, flag, mode, p)
dev_t dev;
int flag;
int mode;
struct proc *p;
{
register struct bpf_d *d = &bpf_dtab[minor(dev)];
register int s;
s = splimp();
if (d->bd_bif)
bpf_detachd(d);
splx(s);
bpf_freed(d);
return (0);
}
/*
* Rotate the packet buffers in descriptor d. Move the store buffer
* into the hold slot, and the free buffer into the store slot.
* Zero the length of the new store buffer.
*/
#define ROTATE_BUFFERS(d) \
(d)->bd_hbuf = (d)->bd_sbuf; \
(d)->bd_hlen = (d)->bd_slen; \
(d)->bd_sbuf = (d)->bd_fbuf; \
(d)->bd_slen = 0; \
(d)->bd_fbuf = 0;
/*
* bpfread - read next chunk of packets from buffers
*/
int
bpfread(dev, uio, ioflag)
dev_t dev;
register struct uio *uio;
int ioflag;
{
register struct bpf_d *d = &bpf_dtab[minor(dev)];
int error;
int s;
if (d->bd_bif == 0)
return (ENXIO);
/*
* Restrict application to use a buffer the same size as
* as kernel buffers.
*/
if (uio->uio_resid != d->bd_bufsize)
return (EINVAL);
s = splimp();
/*
* bd_rdStart is tagged when we start the read, iff there's a timeout.
* we can then figure out when we're done reading.
*/
if (d->bd_rtout != -1 && d->bd_rdStart == 0)
d->bd_rdStart = ticks;
else
d->bd_rdStart = 0;
/*
* If the hold buffer is empty, then do a timed sleep, which
* ends when the timeout expires or when enough packets
* have arrived to fill the store buffer.
*/
while (d->bd_hbuf == 0) {
if (d->bd_immediate && d->bd_slen != 0) {
/*
* A packet(s) either arrived since the previous
* read or arrived while we were asleep.
* Rotate the buffers and return what's here.
*/
ROTATE_BUFFERS(d);
break;
}
if ((d->bd_rtout != -1) || (d->bd_rdStart + d->bd_rtout) < ticks) {
error = tsleep((caddr_t)d, PRINET|PCATCH, "bpf",
d->bd_rtout);
} else {
if (d->bd_rtout == -1) {
/* User requested non-blocking I/O */
error = EWOULDBLOCK;
} else
error = 0;
}
if (error == EINTR || error == ERESTART) {
splx(s);
return (error);
}
if (error == EWOULDBLOCK) {
/*
* On a timeout, return what's in the buffer,
* which may be nothing. If there is something
* in the store buffer, we can rotate the buffers.
*/
if (d->bd_hbuf)
/*
* We filled up the buffer in between
* getting the timeout and arriving
* here, so we don't need to rotate.
*/
break;
if (d->bd_slen == 0) {
splx(s);
return (0);
}
ROTATE_BUFFERS(d);
break;
}
}
/*
* At this point, we know we have something in the hold slot.
*/
splx(s);
/*
* Move data from hold buffer into user space.
* We know the entire buffer is transferred since
* we checked above that the read buffer is bpf_bufsize bytes.
*/
error = uiomove(d->bd_hbuf, d->bd_hlen, uio);
s = splimp();
d->bd_fbuf = d->bd_hbuf;
d->bd_hbuf = 0;
d->bd_hlen = 0;
splx(s);
return (error);
}
/*
* If there are processes sleeping on this descriptor, wake them up.
*/
static __inline void
bpf_wakeup(d)
register struct bpf_d *d;
{
wakeup((caddr_t)d);
if (d->bd_async && d->bd_sig)
csignal(d->bd_pgid, d->bd_sig,
d->bd_siguid, d->bd_sigeuid);
selwakeup(&d->bd_sel);
/* XXX */
d->bd_sel.si_selpid = 0;
}
int
bpfwrite(dev, uio, ioflag)
dev_t dev;
struct uio *uio;
int ioflag;
{
register struct bpf_d *d = &bpf_dtab[minor(dev)];
struct ifnet *ifp;
struct mbuf *m;
int error, s;
struct sockaddr dst;
if (d->bd_bif == 0)
return (ENXIO);
ifp = d->bd_bif->bif_ifp;
if (uio->uio_resid == 0)
return (0);
error = bpf_movein(uio, (int)d->bd_bif->bif_dlt, &m, &dst);
if (error)
return (error);
if (m->m_pkthdr.len > ifp->if_mtu) {
m_freem(m);
return (EMSGSIZE);
}
if (d->bd_hdrcmplt)
dst.sa_family = pseudo_AF_HDRCMPLT;
s = splsoftnet();
error = (*ifp->if_output)(ifp, m, &dst, (struct rtentry *)0);
splx(s);
/*
* The driver frees the mbuf.
*/
return (error);
}
/*
* Reset a descriptor by flushing its packet buffer and clearing the
* receive and drop counts. Should be called at splimp.
*/
void
bpf_reset_d(d)
struct bpf_d *d;
{
if (d->bd_hbuf) {
/* Free the hold buffer. */
d->bd_fbuf = d->bd_hbuf;
d->bd_hbuf = 0;
}
d->bd_slen = 0;
d->bd_hlen = 0;
d->bd_rcount = 0;
d->bd_dcount = 0;
}
/*
* FIONREAD Check for read packet available.
* BIOCGBLEN Get buffer len [for read()].
* BIOCSETF Set ethernet read filter.
* BIOCFLUSH Flush read packet buffer.
* BIOCPROMISC Put interface into promiscuous mode.
* BIOCGDLT Get link layer type.
* BIOCGETIF Get interface name.
* BIOCSETIF Set interface.
* BIOCSRTIMEOUT Set read timeout.
* BIOCGRTIMEOUT Get read timeout.
* BIOCGSTATS Get packet stats.
* BIOCIMMEDIATE Set immediate mode.
* BIOCVERSION Get filter language version.
* BIOCGHDRCMPLT Get "header already complete" flag
* BIOCSHDRCMPLT Set "header already complete" flag
*/
/* ARGSUSED */
int
bpfioctl(dev, cmd, addr, flag, p)
dev_t dev;
u_long cmd;
caddr_t addr;
int flag;
struct proc *p;
{
register struct bpf_d *d = &bpf_dtab[minor(dev)];
int s, error = 0;
switch (cmd) {
default:
error = EINVAL;
break;
/*
* Check for read packet available.
*/
case FIONREAD:
{
int n;
s = splimp();
n = d->bd_slen;
if (d->bd_hbuf)
n += d->bd_hlen;
splx(s);
*(int *)addr = n;
break;
}
/*
* Get buffer len [for read()].
*/
case BIOCGBLEN:
*(u_int *)addr = d->bd_bufsize;
break;
/*
* Set buffer length.
*/
case BIOCSBLEN:
if (d->bd_bif != 0)
error = EINVAL;
else {
register u_int size = *(u_int *)addr;
if (size > BPF_MAXBUFSIZE)
*(u_int *)addr = size = BPF_MAXBUFSIZE;
else if (size < BPF_MINBUFSIZE)
*(u_int *)addr = size = BPF_MINBUFSIZE;
d->bd_bufsize = size;
}
break;
/*
* Set link layer read filter.
*/
case BIOCSETF:
error = bpf_setf(d, (struct bpf_program *)addr);
break;
/*
* Flush read packet buffer.
*/
case BIOCFLUSH:
s = splimp();
bpf_reset_d(d);
splx(s);
break;
/*
* Put interface into promiscuous mode.
*/
case BIOCPROMISC:
if (d->bd_bif == 0) {
/*
* No interface attached yet.
*/
error = EINVAL;
break;
}
s = splimp();
if (d->bd_promisc == 0) {
error = ifpromisc(d->bd_bif->bif_ifp, 1);
if (error == 0)
d->bd_promisc = 1;
}
splx(s);
break;
/*
* Get device parameters.
*/
case BIOCGDLT:
if (d->bd_bif == 0)
error = EINVAL;
else
*(u_int *)addr = d->bd_bif->bif_dlt;
break;
/*
* Set interface name.
*/
case BIOCGETIF:
if (d->bd_bif == 0)
error = EINVAL;
else
bpf_ifname(d->bd_bif->bif_ifp, (struct ifreq *)addr);
break;
/*
* Set interface.
*/
case BIOCSETIF:
error = bpf_setif(d, (struct ifreq *)addr);
break;
/*
* Set read timeout.
*/
case BIOCSRTIMEOUT:
{
struct timeval *tv = (struct timeval *)addr;
/* Compute number of ticks. */
d->bd_rtout = tv->tv_sec * hz + tv->tv_usec / tick;
if (d->bd_rtout == 0 && tv->tv_usec != 0)
d->bd_rtout = 1;
break;
}
/*
* Get read timeout.
*/
case BIOCGRTIMEOUT:
{
struct timeval *tv = (struct timeval *)addr;
tv->tv_sec = d->bd_rtout / hz;
tv->tv_usec = (d->bd_rtout % hz) * tick;
break;
}
/*
* Get packet stats.
*/
case BIOCGSTATS:
{
struct bpf_stat *bs = (struct bpf_stat *)addr;
bs->bs_recv = d->bd_rcount;
bs->bs_drop = d->bd_dcount;
break;
}
/*
* Set immediate mode.
*/
case BIOCIMMEDIATE:
d->bd_immediate = *(u_int *)addr;
break;
case BIOCVERSION:
{
struct bpf_version *bv = (struct bpf_version *)addr;
bv->bv_major = BPF_MAJOR_VERSION;
bv->bv_minor = BPF_MINOR_VERSION;
break;
}
case BIOCGHDRCMPLT: /* get "header already complete" flag */
*(u_int *)addr = d->bd_hdrcmplt;
break;
case BIOCSHDRCMPLT: /* set "header already complete" flag */
d->bd_hdrcmplt = *(u_int *)addr ? 1 : 0;
break;
case FIONBIO: /* Non-blocking I/O */
if (*(int *)addr)
d->bd_rtout = -1;
else
d->bd_rtout = 0;
break;
case FIOASYNC: /* Send signal on receive packets */
d->bd_async = *(int *)addr;
break;
/*
* N.B. ioctl (FIOSETOWN) and fcntl (F_SETOWN) both end up doing
* the equivalent of a TIOCSPGRP and hence end up here. *However*
* TIOCSPGRP's arg is a process group if it's positive and a process
* id if it's negative. This is exactly the opposite of what the
* other two functions want! Therefore there is code in ioctl and
* fcntl to negate the arg before calling here.
*/
case TIOCSPGRP: /* Process or group to send signals to */
d->bd_pgid = *(int *)addr;
d->bd_siguid = p->p_cred->p_ruid;
d->bd_sigeuid = p->p_ucred->cr_uid;
break;
case TIOCGPGRP:
*(int *)addr = d->bd_pgid;
break;
case BIOCSRSIG: /* Set receive signal */
{
u_int sig;
sig = *(u_int *)addr;
if (sig >= NSIG)
error = EINVAL;
else
d->bd_sig = sig;
break;
}
case BIOCGRSIG:
*(u_int *)addr = d->bd_sig;
break;
}
return (error);
}
/*
* Set d's packet filter program to fp. If this file already has a filter,
* free it and replace it. Returns EINVAL for bogus requests.
*/
int
bpf_setf(d, fp)
struct bpf_d *d;
struct bpf_program *fp;
{
struct bpf_insn *fcode, *old;
u_int flen, size;
int s;
old = d->bd_filter;
if (fp->bf_insns == 0) {
if (fp->bf_len != 0)
return (EINVAL);
s = splimp();
d->bd_filter = 0;
bpf_reset_d(d);
splx(s);
if (old != 0)
free((caddr_t)old, M_DEVBUF);
return (0);
}
flen = fp->bf_len;
if (flen > BPF_MAXINSNS)
return (EINVAL);
size = flen * sizeof(*fp->bf_insns);
fcode = (struct bpf_insn *)malloc(size, M_DEVBUF, M_WAITOK);
if (copyin((caddr_t)fp->bf_insns, (caddr_t)fcode, size) == 0 &&
bpf_validate(fcode, (int)flen)) {
s = splimp();
d->bd_filter = fcode;
bpf_reset_d(d);
splx(s);
if (old != 0)
free((caddr_t)old, M_DEVBUF);
return (0);
}
free((caddr_t)fcode, M_DEVBUF);
return (EINVAL);
}
/*
* Detach a file from its current interface (if attached at all) and attach
* to the interface indicated by the name stored in ifr.
* Return an errno or 0.
*/
int
bpf_setif(d, ifr)
struct bpf_d *d;
struct ifreq *ifr;
{
struct bpf_if *bp;
char *cp;
int unit_seen, i, s, error;
/*
* Make sure the provided name has a unit number, and default
* it to '0' if not specified.
* XXX This is ugly ... do this differently?
*/
unit_seen = 0;
cp = ifr->ifr_name;
cp[sizeof(ifr->ifr_name) - 1] = '\0'; /* sanity */
while (*cp++)
if (*cp >= '0' && *cp <= '9')
unit_seen = 1;
if (!unit_seen) {
/* Make sure to leave room for the '\0'. */
for (i = 0; i < (IFNAMSIZ - 1); ++i) {
if ((ifr->ifr_name[i] >= 'a' &&
ifr->ifr_name[i] <= 'z') ||
(ifr->ifr_name[i] >= 'A' &&
ifr->ifr_name[i] <= 'Z'))
continue;
ifr->ifr_name[i] = '0';
}
}
/*
* Look through attached interfaces for the named one.
*/
for (bp = bpf_iflist; bp != 0; bp = bp->bif_next) {
struct ifnet *ifp = bp->bif_ifp;
if (ifp == 0 ||
strcmp(ifp->if_xname, ifr->ifr_name) != 0)
continue;
/*
* We found the requested interface.
* If it's not up, return an error.
* Allocate the packet buffers if we need to.
* If we're already attached to requested interface,
* just flush the buffer.
*/
if ((ifp->if_flags & IFF_UP) == 0)
return (ENETDOWN);
if (d->bd_sbuf == 0) {
error = bpf_allocbufs(d);
if (error != 0)
return (error);
}
s = splimp();
if (bp != d->bd_bif) {
if (d->bd_bif)
/*
* Detach if attached to something else.
*/
bpf_detachd(d);
bpf_attachd(d, bp);
}
bpf_reset_d(d);
splx(s);
return (0);
}
/* Not found. */
return (ENXIO);
}
/*
* Copy the interface name to the ifreq.
*/
void
bpf_ifname(ifp, ifr)
struct ifnet *ifp;
struct ifreq *ifr;
{
bcopy(ifp->if_xname, ifr->ifr_name, IFNAMSIZ);
}
/*
* Support for select() system call
*
* Return true iff the specific operation will not block indefinitely.
* Otherwise, return false but make a note that a selwakeup() must be done.
*/
int
bpfselect(dev, rw, p)
register dev_t dev;
int rw;
struct proc *p;
{
register struct bpf_d *d;
register int s;
if (rw != FREAD)
return (0);
/*
* An imitation of the FIONREAD ioctl code.
*/
d = &bpf_dtab[minor(dev)];
s = splimp();
if (d->bd_hlen != 0 || (d->bd_immediate && d->bd_slen != 0)) {
/*
* There is data waiting.
*/
splx(s);
return (1);
}
/*
* if there isn't data waiting, and there's a timeout,
* mark the time we started waiting.
*/
if (d->bd_rtout != -1 && d->bd_rdStart == 0)
d->bd_rdStart = ticks;
selrecord(p, &d->bd_sel);
splx(s);
return (0);
}
/*
* Incoming linkage from device drivers. Process the packet pkt, of length
* pktlen, which is stored in a contiguous buffer. The packet is parsed
* by each process' filter, and if accepted, stashed into the corresponding
* buffer.
*/
void
bpf_tap(arg, pkt, pktlen)
caddr_t arg;
register u_char *pkt;
register u_int pktlen;
{
struct bpf_if *bp;
register struct bpf_d *d;
register size_t slen;
/*
* Note that the ipl does not have to be raised at this point.
* The only problem that could arise here is that if two different
* interfaces shared any data. This is not the case.
*/
bp = (struct bpf_if *)arg;
for (d = bp->bif_dlist; d != 0; d = d->bd_next) {
++d->bd_rcount;
slen = bpf_filter(d->bd_filter, pkt, pktlen, pktlen);
if (slen != 0)
bpf_catchpacket(d, pkt, pktlen, slen, bcopy);
}
}
/*
* Copy data from an mbuf chain into a buffer. This code is derived
* from m_copydata in sys/uipc_mbuf.c.
*/
void
bpf_mcopy(src_arg, dst_arg, len)
const void *src_arg;
void *dst_arg;
register size_t len;
{
register const struct mbuf *m;
register u_int count;
u_char *dst;
m = src_arg;
dst = dst_arg;
while (len > 0) {
if (m == 0)
panic("bpf_mcopy");
count = min(m->m_len, len);
bcopy(mtod(m, caddr_t), (caddr_t)dst, count);
m = m->m_next;
dst += count;
len -= count;
}
}
/*
* Incoming linkage from device drivers, when packet is in an mbuf chain.
*/
void
bpf_mtap(arg, m)
caddr_t arg;
struct mbuf *m;
{
struct bpf_if *bp = (struct bpf_if *)arg;
struct bpf_d *d;
size_t pktlen, slen;
struct mbuf *m0;
if (m == NULL)
return;
pktlen = 0;
for (m0 = m; m0 != 0; m0 = m0->m_next)
pktlen += m0->m_len;
for (d = bp->bif_dlist; d != 0; d = d->bd_next) {
++d->bd_rcount;
slen = bpf_filter(d->bd_filter, (u_char *)m, pktlen, 0);
if (slen != 0)
bpf_catchpacket(d, (u_char *)m, pktlen, slen, bpf_mcopy);
}
}
/*
* Move the packet data from interface memory (pkt) into the
* store buffer. Return 1 if it's time to wakeup a listener (buffer full),
* otherwise 0. "copy" is the routine called to do the actual data
* transfer. bcopy is passed in to copy contiguous chunks, while
* bpf_mcopy is passed in to copy mbuf chains. In the latter case,
* pkt is really an mbuf.
*/
void
bpf_catchpacket(d, pkt, pktlen, snaplen, cpfn)
register struct bpf_d *d;
register u_char *pkt;
register size_t pktlen, snaplen;
register void (*cpfn) __P((const void *, void *, size_t));
{
register struct bpf_hdr *hp;
register int totlen, curlen;
register int hdrlen = d->bd_bif->bif_hdrlen;
struct timeval tv;
/*
* Figure out how many bytes to move. If the packet is
* greater or equal to the snapshot length, transfer that
* much. Otherwise, transfer the whole packet (unless
* we hit the buffer size limit).
*/
totlen = hdrlen + min(snaplen, pktlen);
if (totlen > d->bd_bufsize)
totlen = d->bd_bufsize;
/*
* Round up the end of the previous packet to the next longword.
*/
curlen = BPF_WORDALIGN(d->bd_slen);
if (curlen + totlen > d->bd_bufsize) {
/*
* This packet will overflow the storage buffer.
* Rotate the buffers if we can, then wakeup any
* pending reads.
*/
if (d->bd_fbuf == 0) {
/*
* We haven't completed the previous read yet,
* so drop the packet.
*/
++d->bd_dcount;
return;
}
ROTATE_BUFFERS(d);
bpf_wakeup(d);
curlen = 0;
}
else if (d->bd_immediate) {
/*
* Immediate mode is set. A packet arrived so any
* reads should be woken up.
*/
bpf_wakeup(d);
}
/*
* Append the bpf header.
*/
hp = (struct bpf_hdr *)(d->bd_sbuf + curlen);
microtime(&tv);
hp->bh_tstamp.tv_sec = tv.tv_sec;
hp->bh_tstamp.tv_usec = tv.tv_usec;
hp->bh_datalen = pktlen;
hp->bh_hdrlen = hdrlen;
/*
* Copy the packet data into the store buffer and update its length.
*/
(*cpfn)(pkt, (u_char *)hp + hdrlen, (hp->bh_caplen = totlen - hdrlen));
d->bd_slen = curlen + totlen;
if (d->bd_rdStart && (d->bd_rtout + d->bd_rdStart < ticks)) {
/*
* we could be selecting on the bpf, and we
* may have timeouts set. We got here by getting
* a packet, so wake up the reader.
*/
if (d->bd_fbuf) {
d->bd_rdStart = 0;
ROTATE_BUFFERS(d);
bpf_wakeup(d);
curlen = 0;
}
}
}
/*
* Initialize all nonzero fields of a descriptor.
*/
int
bpf_allocbufs(d)
register struct bpf_d *d;
{
d->bd_fbuf = (caddr_t)malloc(d->bd_bufsize, M_DEVBUF, M_WAITOK);
d->bd_sbuf = (caddr_t)malloc(d->bd_bufsize, M_DEVBUF, M_WAITOK);
d->bd_slen = 0;
d->bd_hlen = 0;
return (0);
}
/*
* Free buffers currently in use by a descriptor.
* Called on close.
*/
void
bpf_freed(d)
register struct bpf_d *d;
{
/*
* We don't need to lock out interrupts since this descriptor has
* been detached from its interface and it yet hasn't been marked
* free.
*/
if (d->bd_sbuf != 0) {
free(d->bd_sbuf, M_DEVBUF);
if (d->bd_hbuf != 0)
free(d->bd_hbuf, M_DEVBUF);
if (d->bd_fbuf != 0)
free(d->bd_fbuf, M_DEVBUF);
}
if (d->bd_filter)
free((caddr_t)d->bd_filter, M_DEVBUF);
D_MARKFREE(d);
}
/*
* Attach an interface to bpf. driverp is a pointer to a (struct bpf_if *)
* in the driver's softc; dlt is the link layer type; hdrlen is the fixed
* size of the link header (variable length headers not yet supported).
*/
void
bpfattach(driverp, ifp, dlt, hdrlen)
caddr_t *driverp;
struct ifnet *ifp;
u_int dlt, hdrlen;
{
struct bpf_if *bp;
bp = (struct bpf_if *)malloc(sizeof(*bp), M_DEVBUF, M_DONTWAIT);
if (bp == 0)
panic("bpfattach");
bp->bif_dlist = 0;
bp->bif_driverp = (struct bpf_if **)driverp;
bp->bif_ifp = ifp;
bp->bif_dlt = dlt;
bp->bif_next = bpf_iflist;
bpf_iflist = bp;
*bp->bif_driverp = 0;
/*
* Compute the length of the bpf header. This is not necessarily
* equal to SIZEOF_BPF_HDR because we want to insert spacing such
* that the network layer header begins on a longword boundary (for
* performance reasons and to alleviate alignment restrictions).
*/
bp->bif_hdrlen = BPF_WORDALIGN(hdrlen + SIZEOF_BPF_HDR) - hdrlen;
}
/* Detach an interface from its attached bpf device. */
void
bpfdetach(ifp)
struct ifnet *ifp;
{
struct bpf_if *bp, *nbp, **pbp = &bpf_iflist;
struct bpf_d *bd;
int maj, mn;
for (bp = bpf_iflist; bp; bp = nbp) {
nbp= bp->bif_next;
if (bp->bif_ifp == ifp) {
*pbp = nbp;
/* Locate the major number. */
for (maj = 0; maj < nchrdev; maj++)
if (cdevsw[maj].d_open == bpfopen)
break;
for (bd = bp->bif_dlist; bd; bd = bp->bif_dlist)
/*
* Locate the minor number and nuke the vnode
* for any open instance.
*/
for (mn = 0; mn < nbpfilter; mn++)
if (&bpf_dtab[mn] == bd) {
vdevgone(maj, mn, mn, VCHR);
break;
}
free(bp, M_DEVBUF);
} else
pbp = &bp->bif_next;
}
ifp->if_bpf = NULL;
}
|