-
Notifications
You must be signed in to change notification settings - Fork 854
/
pcap-dag.c
1745 lines (1544 loc) · 48.4 KB
/
pcap-dag.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
/*
* pcap-dag.c: Packet capture interface for Endace DAG cards.
*
* Authors: Richard Littin, Sean Irvine ({richard,sean}@reeltwo.com)
* Modifications: Jesper Peterson
* Koryn Grant
* Stephen Donnelly <[email protected]>
*/
#include <config.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <endian.h>
#include <limits.h>
#include <unistd.h>
#include "pcap-int.h"
#include "dagapi.h"
#include "dagpci.h"
#include "dag_config_api.h"
#include "pcap-dag.h"
/*
* DAG devices have names beginning with "dag", followed by a number
* from 0 to DAG_MAX_BOARDS, then optionally a colon and a stream number
* from 0 to DAG_STREAM_MAX.
*/
#ifndef DAG_MAX_BOARDS
#define DAG_MAX_BOARDS 32
#endif
#define ATM_CELL_SIZE 52
#define ATM_HDR_SIZE 4
/*
* A header containing additional MTP information.
*/
#define MTP2_SENT_OFFSET 0 /* 1 byte */
#define MTP2_ANNEX_A_USED_OFFSET 1 /* 1 byte */
#define MTP2_LINK_NUMBER_OFFSET 2 /* 2 bytes */
#define MTP2_HDR_LEN 4 /* length of the header */
#define MTP2_ANNEX_A_NOT_USED 0
#define MTP2_ANNEX_A_USED 1
#define MTP2_ANNEX_A_USED_UNKNOWN 2
/* SunATM pseudo header */
struct sunatm_hdr {
unsigned char flags; /* destination and traffic type */
unsigned char vpi; /* VPI */
unsigned short vci; /* VCI */
};
/*
* Private data for capturing on DAG devices.
*/
struct pcap_dag {
struct pcap_stat stat;
u_char *dag_mem_bottom; /* DAG card current memory bottom pointer */
u_char *dag_mem_top; /* DAG card current memory top pointer */
int dag_fcs_bits; /* Number of checksum bits from link layer */
int dag_flags; /* Flags */
int dag_devnum; /* This is the N in "dagN" or "dagN:M". */
int dag_stream; /* And this is the M. */
int dag_timeout; /* timeout specified to pcap_open_live.
* Same as in linux above, introduce
* generally? */
dag_card_ref_t dag_ref; /* DAG Configuration/Status API card reference */
dag_component_t dag_root; /* DAG CSAPI Root component */
attr_uuid_t drop_attr; /* DAG Stream Drop Attribute handle, if available */
uint64_t drop_base; // Rx stream drop counter initial value.
struct timeval required_select_timeout;
/* Timeout caller must use in event loops */
uint8_t tx_iface; // Tx interface number
uint8_t tx_align_bytes; /* If necessary, add trailing padding to an
* ERF record to make it a multiple of this
* many bytes long. DAG API calls this "ERF
* record alignment". */
uint8_t terf_fcs_bytes; // How many FCS bytes TERF is expecting.
};
#define ALIGN_BYTES_DEFAULT 8
#define ALIGN_BYTES_9_2 16
#define ALIGN_BYTES_MAX ALIGN_BYTES_9_2
typedef struct pcap_dag_node {
struct pcap_dag_node *next;
pcap_t *p;
pid_t pid;
} pcap_dag_node_t;
static pcap_dag_node_t *pcap_dags = NULL;
static int atexit_handler_installed = 0;
#define MAX_DAG_PACKET 65536
static unsigned char TempPkt[MAX_DAG_PACKET];
#define TX_ONLY(stream) ((stream) % 2)
#define RX_ONLY(stream) (! TX_ONLY(stream))
#define RXTX_STR(stream) (TX_ONLY(stream) ? "Tx" : "Rx")
static int dag_stats(pcap_t *p, struct pcap_stat *ps);
static int dag_set_datalink(pcap_t *p, int dlt);
static int dag_get_datalink(pcap_t *p);
static int dag_setnonblock(pcap_t *p, int nonblock);
// Environment variables that can control behaviour of this libpcap module.
#define ENV_RX_FCS_BITS "ERF_FCS_BITS"
#define ENV_RX_FCS_NOSTRIP "ERF_DONT_STRIP_FCS"
#define ENV_TX_IFACE "ERF_TX_INTERFACE"
/*
* Convert the return value of getenv() to an integer using matching stricter
* than atoi(). If the environment variable is not set, return the default
* value. Otherwise return an integer in the interval [0, INT32_MAX] or -1 on
* error.
*/
static int32_t
strtouint31(const char *str, const int32_t defaultval) {
if (! str)
return defaultval;
if (! str[0])
return -1;
char * endp;
unsigned long val = strtoul(str, &endp, 10);
if (*endp || val > INT32_MAX)
return -1;
return (int32_t)val;
}
static void
delete_pcap_dag(const pcap_t *p)
{
pcap_dag_node_t *curr = NULL, *prev = NULL;
for (prev = NULL, curr = pcap_dags; curr != NULL && curr->p != p; prev = curr, curr = curr->next) {
/* empty */
}
if (curr != NULL && curr->p == p) {
if (prev != NULL) {
prev->next = curr->next;
} else {
pcap_dags = curr->next;
}
}
}
/*
* Performs a graceful shutdown of the DAG card, frees dynamic memory held
* in the pcap_t structure, and closes the file descriptor for the DAG card.
*/
static void
dag_platform_cleanup(pcap_t *p)
{
struct pcap_dag *pd = p->priv;
/*
* Before stopping a Tx stream wait until the stream buffer has been
* drained, otherwise packets that have been buffered but have not yet
* been transmitted will be lost.
*/
if (TX_ONLY(pd->dag_stream))
while (dag_get_stream_buffer_level64(p->fd, pd->dag_stream) > 0)
usleep (10000);
if(dag_stop_stream(p->fd, pd->dag_stream) < 0)
fprintf(stderr,"dag_stop_stream: %s\n", strerror(errno));
if(dag_detach_stream(p->fd, pd->dag_stream) < 0)
fprintf(stderr,"dag_detach_stream: %s\n", strerror(errno));
if(pd->dag_ref != NULL) {
dag_config_dispose(pd->dag_ref);
/*
* Note: we don't need to call close(p->fd) or
* dag_close(p->fd), as dag_config_dispose(pd->dag_ref)
* does this.
*
* Set p->fd to -1 to make sure that's not done.
*/
p->fd = -1;
pd->dag_ref = NULL;
}
delete_pcap_dag(p);
pcapint_cleanup_live_common(p);
}
static void
atexit_handler(void)
{
while (pcap_dags != NULL) {
if (pcap_dags->pid == getpid()) {
if (pcap_dags->p != NULL)
dag_platform_cleanup(pcap_dags->p);
} else {
delete_pcap_dag(pcap_dags->p);
}
}
}
static int
new_pcap_dag(pcap_t *p)
{
pcap_dag_node_t *node = NULL;
if ((node = malloc(sizeof(pcap_dag_node_t))) == NULL) {
return -1;
}
if (!atexit_handler_installed) {
atexit(atexit_handler);
atexit_handler_installed = 1;
}
node->next = pcap_dags;
node->p = p;
node->pid = getpid();
pcap_dags = node;
return 0;
}
static unsigned int
dag_erf_ext_header_count(const uint8_t *erf, size_t len)
{
uint32_t hdr_num = 0;
uint8_t hdr_type;
/* basic sanity checks */
if ( erf == NULL )
return 0;
if ( len < 16 )
return 0;
/* check if we have any extension headers */
if (! (erf[8] & ERF_TYPE_MORE_EXT))
return 0;
/* loop over the extension headers */
do {
/* sanity check we have enough bytes */
if ( len < (24 + (hdr_num * 8)) )
return hdr_num;
/* get the header type */
hdr_type = erf[(16 + (hdr_num * 8))];
hdr_num++;
} while (hdr_type & ERF_TYPE_MORE_EXT);
return hdr_num;
}
static int
dag_rxtx_mismatch(pcap_t *p)
{
const struct pcap_dag *pd = p->priv;
snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "device %s is %s-only",
p->opt.device,
RXTX_STR(pd->dag_stream));
return PCAP_ERROR;
}
static int
dag_read_notimpl(pcap_t *p, int cnt _U_, pcap_handler callback _U_, u_char *user _U_)
{
return dag_rxtx_mismatch(p);
}
static int
dag_getnonblock_fd_notimpl(pcap_t *p)
{
return dag_rxtx_mismatch(p);
}
static int
dag_stats_notimpl(pcap_t *p, struct pcap_stat *ps _U_)
{
return dag_rxtx_mismatch(p);
}
static int
dag_setnonblock_notimpl(pcap_t *p, int nonblock _U_)
{
return dag_rxtx_mismatch(p);
}
static int
dag_inject_notimpl(pcap_t *p, const void *buf _U_, int size _U_)
{
return dag_rxtx_mismatch(p);
}
static int
dag_install_bpf_program_notimpl(pcap_t *p, struct bpf_program *fp _U_)
{
return dag_rxtx_mismatch(p);
}
/*
* Read at most max_packets from the capture stream and call the callback
* for each of them. Returns the number of packets handled, PCAP_ERROR if an
* error occurred, or PCAP_ERROR_BREAK if we were told to break out of the loop.
*/
static int
dag_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
{
struct pcap_dag *pd = p->priv;
int processed = 0;
unsigned int nonblocking = pd->dag_flags & DAGF_NONBLOCK;
unsigned int num_ext_hdr = 0;
unsigned int ticks_per_second;
/* Get the next bufferful of packets (if necessary). */
while (pd->dag_mem_top - pd->dag_mem_bottom < dag_record_size) {
/*
* Has "pcap_breakloop()" been called?
*/
if (p->break_loop) {
/*
* Yes - clear the flag that indicates that
* it has, and return PCAP_ERROR_BREAK to indicate that
* we were told to break out of the loop.
*/
p->break_loop = 0;
return PCAP_ERROR_BREAK;
}
/* dag_advance_stream() will block (unless nonblock is called)
* until 64kB of data has accumulated.
* If to_ms is set, it will timeout before 64kB has accumulated.
* We wait for 64kB because processing a few packets at a time
* can cause problems at high packet rates (>200kpps) due
* to inefficiencies.
* This does mean if to_ms is not specified the capture may 'hang'
* for long periods if the data rate is extremely slow (<64kB/sec)
* If non-block is specified it will return immediately. The user
* is then responsible for efficiency.
*/
if ( NULL == (pd->dag_mem_top = dag_advance_stream(p->fd, pd->dag_stream, &(pd->dag_mem_bottom))) ) {
return PCAP_ERROR;
}
if (nonblocking && (pd->dag_mem_top - pd->dag_mem_bottom < dag_record_size))
{
/* Pcap is configured to process only available packets, and there aren't any, return immediately. */
return 0;
}
if(!nonblocking &&
pd->dag_timeout &&
(pd->dag_mem_top - pd->dag_mem_bottom < dag_record_size))
{
/* Blocking mode, but timeout set and no data has arrived, return anyway.*/
return 0;
}
}
/*
* Process the packets.
*
* This assumes that a single buffer of packets will have
* <= INT_MAX packets, so the packet count doesn't overflow.
*/
while (pd->dag_mem_top - pd->dag_mem_bottom >= dag_record_size) {
unsigned short packet_len = 0;
int caplen = 0;
struct pcap_pkthdr pcap_header;
dag_record_t *header = (dag_record_t *)(pd->dag_mem_bottom);
u_char *dp = ((u_char *)header); /* + dag_record_size; */
unsigned short rlen;
/*
* Has "pcap_breakloop()" been called?
*/
if (p->break_loop) {
/*
* Yes - clear the flag that indicates that
* it has, and return PCAP_ERROR_BREAK to indicate that
* we were told to break out of the loop.
*/
p->break_loop = 0;
return PCAP_ERROR_BREAK;
}
rlen = ntohs(header->rlen);
if (rlen < dag_record_size)
{
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
"%s: record too small", __func__);
return PCAP_ERROR;
}
pd->dag_mem_bottom += rlen;
uint8_t erf_type = header->type & ERF_TYPE_MASK;
/* Count lost packets. */
switch(erf_type) {
/* in these types the color value overwrites the lctr */
case ERF_TYPE_COLOR_HDLC_POS:
case ERF_TYPE_COLOR_ETH:
case ERF_TYPE_DSM_COLOR_HDLC_POS:
case ERF_TYPE_DSM_COLOR_ETH:
case ERF_TYPE_COLOR_MC_HDLC_POS:
case ERF_TYPE_COLOR_HASH_ETH:
case ERF_TYPE_COLOR_HASH_POS:
break;
default:
if ( (pd->drop_attr == kNullAttributeUuid) && (header->lctr) ) {
pd->stat.ps_drop += ntohs(header->lctr);
}
}
if (erf_type == ERF_TYPE_PAD) {
continue;
}
num_ext_hdr = dag_erf_ext_header_count(dp, rlen);
/* ERF encapsulation */
/* The Extensible Record Format is not dropped for this kind of encapsulation,
* and will be handled as a pseudo header by the decoding application.
* The information carried in the ERF header and in the optional subheader (if present)
* could be merged with the libpcap information, to offer a better decoding.
* The packet length is
* o the length of the packet on the link (header->wlen),
* o plus the length of the ERF header (dag_record_size), as the length of the
* pseudo header will be adjusted during the decoding,
* o plus the length of the optional subheader (if present).
*
* The capture length is header.rlen and the byte stuffing for alignment will be dropped
* if the capture length is greater than the packet length.
*/
if (p->linktype == DLT_ERF) {
packet_len = ntohs(header->wlen) + dag_record_size;
caplen = rlen;
switch (erf_type) {
case ERF_TYPE_MC_AAL5:
case ERF_TYPE_MC_ATM:
case ERF_TYPE_MC_HDLC:
case ERF_TYPE_MC_RAW_CHANNEL:
case ERF_TYPE_MC_RAW:
case ERF_TYPE_MC_AAL2:
case ERF_TYPE_COLOR_MC_HDLC_POS:
packet_len += 4; /* MC header */
break;
case ERF_TYPE_COLOR_HASH_ETH:
case ERF_TYPE_DSM_COLOR_ETH:
case ERF_TYPE_COLOR_ETH:
case ERF_TYPE_ETH:
packet_len += 2; /* ETH header */
break;
} /* switch type */
/* Include ERF extension headers */
packet_len += (8 * num_ext_hdr);
if (caplen > packet_len) {
caplen = packet_len;
}
} else {
/* Other kind of encapsulation according to the header Type */
/* Skip over generic ERF header */
dp += dag_record_size;
/* Skip over extension headers */
dp += 8 * num_ext_hdr;
switch(erf_type) {
case ERF_TYPE_ATM:
case ERF_TYPE_AAL5:
if (erf_type == ERF_TYPE_AAL5) {
packet_len = ntohs(header->wlen);
caplen = rlen - dag_record_size;
}
/* FALLTHROUGH */
case ERF_TYPE_MC_ATM:
if (erf_type == ERF_TYPE_MC_ATM) {
caplen = packet_len = ATM_CELL_SIZE;
dp+=4;
}
/* FALLTHROUGH */
case ERF_TYPE_MC_AAL5:
if (erf_type == ERF_TYPE_MC_AAL5) {
packet_len = ntohs(header->wlen);
caplen = rlen - dag_record_size - 4;
dp+=4;
}
/* Skip over extension headers */
caplen -= (8 * num_ext_hdr);
if (erf_type == ERF_TYPE_ATM) {
caplen = packet_len = ATM_CELL_SIZE;
}
if (p->linktype == DLT_SUNATM) {
struct sunatm_hdr *sunatm = (struct sunatm_hdr *)dp;
unsigned long rawatm;
rawatm = ntohl(*((uint32_t *)dp));
sunatm->vci = htons((rawatm >> 4) & 0xffff);
sunatm->vpi = (rawatm >> 20) & 0x00ff;
sunatm->flags = ((header->flags.iface & 1) ? 0x80 : 0x00) |
((sunatm->vpi == 0 && sunatm->vci == htons(5)) ? 6 :
((sunatm->vpi == 0 && sunatm->vci == htons(16)) ? 5 :
((dp[ATM_HDR_SIZE] == 0xaa &&
dp[ATM_HDR_SIZE+1] == 0xaa &&
dp[ATM_HDR_SIZE+2] == 0x03) ? 2 : 1)));
} else if (p->linktype == DLT_ATM_RFC1483) {
packet_len -= ATM_HDR_SIZE;
caplen -= ATM_HDR_SIZE;
dp += ATM_HDR_SIZE;
} else
continue;
break;
case ERF_TYPE_COLOR_HASH_ETH:
case ERF_TYPE_DSM_COLOR_ETH:
case ERF_TYPE_COLOR_ETH:
case ERF_TYPE_ETH:
if ((p->linktype != DLT_EN10MB) &&
(p->linktype != DLT_DOCSIS))
continue;
packet_len = ntohs(header->wlen);
packet_len -= (pd->dag_fcs_bits >> 3);
caplen = rlen - dag_record_size - 2;
/* Skip over extension headers */
caplen -= (8 * num_ext_hdr);
if (caplen > packet_len) {
caplen = packet_len;
}
dp += 2;
break;
case ERF_TYPE_COLOR_HASH_POS:
case ERF_TYPE_DSM_COLOR_HDLC_POS:
case ERF_TYPE_COLOR_HDLC_POS:
case ERF_TYPE_HDLC_POS:
if ((p->linktype != DLT_CHDLC) &&
(p->linktype != DLT_PPP_SERIAL) &&
(p->linktype != DLT_FRELAY))
continue;
packet_len = ntohs(header->wlen);
packet_len -= (pd->dag_fcs_bits >> 3);
caplen = rlen - dag_record_size;
/* Skip over extension headers */
caplen -= (8 * num_ext_hdr);
if (caplen > packet_len) {
caplen = packet_len;
}
break;
case ERF_TYPE_COLOR_MC_HDLC_POS:
case ERF_TYPE_MC_HDLC:
if ((p->linktype != DLT_CHDLC) &&
(p->linktype != DLT_PPP_SERIAL) &&
(p->linktype != DLT_FRELAY) &&
(p->linktype != DLT_MTP2) &&
(p->linktype != DLT_MTP2_WITH_PHDR) &&
(p->linktype != DLT_LAPD))
continue;
packet_len = ntohs(header->wlen);
packet_len -= (pd->dag_fcs_bits >> 3);
caplen = rlen - dag_record_size - 4;
/* Skip over extension headers */
caplen -= (8 * num_ext_hdr);
if (caplen > packet_len) {
caplen = packet_len;
}
/* jump the MC_HDLC_HEADER */
dp += 4;
if (p->linktype == DLT_MTP2_WITH_PHDR) {
/* Add the MTP2 Pseudo Header */
caplen += MTP2_HDR_LEN;
packet_len += MTP2_HDR_LEN;
TempPkt[MTP2_SENT_OFFSET] = 0;
TempPkt[MTP2_ANNEX_A_USED_OFFSET] = MTP2_ANNEX_A_USED_UNKNOWN;
*(TempPkt+MTP2_LINK_NUMBER_OFFSET) = ((header->rec.mc_hdlc.mc_header>>16)&0x01);
*(TempPkt+MTP2_LINK_NUMBER_OFFSET+1) = ((header->rec.mc_hdlc.mc_header>>24)&0xff);
memcpy(TempPkt+MTP2_HDR_LEN, dp, caplen);
dp = TempPkt;
}
break;
case ERF_TYPE_IPV4:
if ((p->linktype != DLT_RAW) &&
(p->linktype != DLT_IPV4))
continue;
packet_len = ntohs(header->wlen);
caplen = rlen - dag_record_size;
/* Skip over extension headers */
caplen -= (8 * num_ext_hdr);
if (caplen > packet_len) {
caplen = packet_len;
}
break;
case ERF_TYPE_IPV6:
if ((p->linktype != DLT_RAW) &&
(p->linktype != DLT_IPV6))
continue;
packet_len = ntohs(header->wlen);
caplen = rlen - dag_record_size;
/* Skip over extension headers */
caplen -= (8 * num_ext_hdr);
if (caplen > packet_len) {
caplen = packet_len;
}
break;
/* These types have no matching 'native' DLT, but can be used with DLT_ERF above */
case ERF_TYPE_MC_RAW:
case ERF_TYPE_MC_RAW_CHANNEL:
case ERF_TYPE_IP_COUNTER:
case ERF_TYPE_TCP_FLOW_COUNTER:
case ERF_TYPE_INFINIBAND:
case ERF_TYPE_RAW_LINK:
case ERF_TYPE_INFINIBAND_LINK:
default:
/* Unhandled ERF type.
* Ignore rather than generating error
*/
continue;
} /* switch type */
} /* ERF encapsulation */
/*
* In this libpcap module the two length arguments of
* pcapint_filter() (the wire length and the captured length)
* can have different values.
*
* The wire length of this packet is packet_len, which is
* derived from ERF wlen; the captured length of this packet
* is caplen, which is derived from ERF rlen, which in turn
* depends on the card/stream slen; the snapshot length
* configured for this pcap handle is p->snapshot.
*/
if ((p->fcode.bf_insns == NULL) || pcapint_filter(p->fcode.bf_insns, dp, packet_len, caplen)) {
/* convert between timestamp formats */
register unsigned long long ts;
#if __BYTE_ORDER == __BIG_ENDIAN
ts = SWAPLL(header->ts);
#else
ts = header->ts;
#endif // __BYTE_ORDER
switch (p->opt.tstamp_precision) {
case PCAP_TSTAMP_PRECISION_NANO:
ticks_per_second = 1000000000;
break;
case PCAP_TSTAMP_PRECISION_MICRO:
default:
ticks_per_second = 1000000;
break;
}
pcap_header.ts.tv_sec = ts >> 32;
ts = (ts & 0xffffffffULL) * ticks_per_second;
ts += 0x80000000; /* rounding */
pcap_header.ts.tv_usec = ts >> 32;
if (pcap_header.ts.tv_usec >= ticks_per_second) {
pcap_header.ts.tv_usec -= ticks_per_second;
pcap_header.ts.tv_sec++;
}
/* Fill in our own header data */
pcap_header.caplen = min(caplen, p->snapshot);
pcap_header.len = packet_len;
/* Count the packet. */
pd->stat.ps_recv++;
/* Call the user supplied callback function */
callback(user, &pcap_header, dp);
/* Only count packets that pass the filter, for consistency with standard Linux behaviour. */
processed++;
if (processed == cnt && !PACKET_COUNT_IS_UNLIMITED(cnt))
{
/* Reached the user-specified limit. */
return cnt;
}
}
}
return processed;
}
/*
* The minimum number of bytes in a valid Ethernet packet from the beginning
* of the destination MAC address to the end of the payload, as far as DAG
* TERF and IEEE 802.3 are concerned.
*/
#define ETH_MINLEN_NOFCS 60
// ...and the maximum, as far as DAG TERF is concerned.
#define ETH_MAXLEN_NOFCS 9596
/*
* The minimum number of bytes in a valid Ethernet header: the destination and
* the source MAC addresses, the EtherType. (This does not take 802.1Q or
* Q-in-Q into account.)
*/
#define ETH_MINLEN_HDRONLY 14
// Zero padding source (a bit oversized for ERF_TYPE_ETH purposes).
static const uint8_t tx_pad[ETH_MINLEN_NOFCS + 4 + ALIGN_BYTES_MAX];
/*
* Take an Ethernet frame, build an ERF record around it and feed the record
* into the [Tx-only] DAG stream. The frame must not include FCS, which is
* usually the case for DLT_EN10MB in libpcap.
*/
static int
dag_inject(pcap_t *p, const void *packet, const int plen)
{
struct pcap_dag *pd = p->priv;
if (plen <= ETH_MINLEN_HDRONLY || plen > ETH_MAXLEN_NOFCS) {
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
"invalid packet size %d", plen);
return PCAP_ERROR;
}
/*
* sizeof(struct dag_record_t) cannot be used because it is much
* greater than the specific ERF header in this buffer.
*/
const dag_size_t hlen = dag_record_size + 2;
/*
* Some DAG hardware (e.g. 7.5G2) automatically pads outgoing Ethernet
* frames that are shorter than the minimum length to make them long
* enough. Other DAG hardware (e.g. 9.2X2) rejects such frames. Pad
* the frame here if necessary and remove this difference from the
* problem space.
*
* If the TERF is expecting Ethernet frames to have a non-zero number
* of FCS bytes (typically in order to strip the FCS correctly before
* further processing), append a dummy zero FCS of the expected size.
*/
const unsigned eth_pad_len = ETH_MINLEN_NOFCS
- min(plen, ETH_MINLEN_NOFCS) + pd->terf_fcs_bytes;
const unsigned rlen = hlen + plen + eth_pad_len;
const unsigned erf_pad_len = rlen % pd->tx_align_bytes ?
pd->tx_align_bytes - rlen % pd->tx_align_bytes :
0;
dag_record_t header = {
.type = ERF_TYPE_ETH,
.flags.vlen = 1,
.rlen = htons(rlen + erf_pad_len),
.wlen = htons(plen + eth_pad_len),
// Silence a -Wmissing-field-initializers from old GCC.
.rec.eth = {0},
};
DAG_ERF_SET_IFACE(&header, pd->tx_iface);
/*
* It is fine to feed less data than a complete ERF record at a time so
* long as a complete and well-formed ERF record eventually makes it
* into the buffer. This simplifies the process when different parts
* of the ERF record come from different memory locations.
*/
if (dag_tx_stream_copy_bytes64(p->fd, pd->dag_stream, (uint8_t *)&header, hlen) < 0 ||
dag_tx_stream_copy_bytes64(p->fd, pd->dag_stream, (uint8_t *)packet, plen) < 0)
goto fail;
/*
* Possibly pad to the minimum packet length and/or append a dummy FCS
* and/or pad to the next multiple of the detected alignment unit.
*/
const unsigned pad_len = eth_pad_len + erf_pad_len;
if (pad_len &&
dag_tx_stream_copy_bytes64(p->fd, pd->dag_stream, (uint8_t *)tx_pad, pad_len) < 0)
goto fail;
return plen;
fail:
pcapint_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
errno, "dag_tx_stream_copy_bytes64 %s", p->opt.device);
return PCAP_ERROR;
}
static int
dag_activate_tx(pcap_t *p)
{
struct pcap_dag *pd = p->priv;
const char * env = getenv(ENV_TX_IFACE);
int32_t iface = strtouint31(env, 0);
if (iface < 0) {
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
"%s: failed parsing %s value \"%s\"",
__func__, ENV_TX_IFACE, env);
return PCAP_ERROR;
}
uint32_t ifcount = dag_config_get_interface_count(pd->dag_ref);
if ((uint32_t)iface >= ifcount) {
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
"%s: invalid %s value %u: this card has %u interface(s)",
__func__, ENV_TX_IFACE, iface, ifcount);
return PCAP_ERROR;
}
pd->tx_iface = (uint8_t)iface;
// Read the TERF FCS size for later use by dag_inject().
dag_component_t cfg_comp = dag_component_get_subcomponent(
pd->dag_root, kComponentTerf, 0);
if (! cfg_comp) {
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
"%s: dag_component_get_subcomponent",
__func__);
return PCAP_ERROR;
}
attr_uuid_t cfg_uuid = dag_component_get_config_attribute_uuid(
cfg_comp, kUint32AttributeTerfStripCrc);
if (cfg_uuid == kNullAttributeUuid) {
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
"%s: dag_component_get_config_attribute_uuid",
__func__);
return PCAP_ERROR;
}
uint32_t cfg_uint32;
dag_err_t cfg_err = dag_config_get_uint32_attribute_ex(pd->dag_ref,
cfg_uuid, &cfg_uint32);
if (cfg_err != kDagErrNone) {
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
"%s: dag_config_get_uint32_attribute_ex",
__func__);
return PCAP_ERROR;
}
switch (cfg_uint32) {
case kTerfNoStrip:
pd->terf_fcs_bytes = 0;
break;
case kTerfStrip16:
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
"TERF FCS is configured to 16 bits, is this Ethernet?");
return PCAP_ERROR;
case kTerfStrip32:
pd->terf_fcs_bytes = 4;
break;
default:
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
"failed reading TERF FCS configuration");
return PCAP_ERROR;
}
/*
* TODO: It would be nice to verify that the Tx port is
* configured for 32-bit Tx FCS, but it is not trivial to
* tell the exact subcomponent that has the attribute.
*/
// Determine the correct alignment/padding size for the card.
const dag_card_inf_t *inf = dag_pciinfo(p->fd);
if (! inf) {
pcapint_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
errno, "dag_pciinfo");
return PCAP_ERROR;
}
switch(inf->device_code) {
case PCI_DEVICE_ID_DAG9_2X2:
case PCI_DEVICE_ID_DAG9_2SX2:
pd->tx_align_bytes = ALIGN_BYTES_9_2;
break;
default:
pd->tx_align_bytes = ALIGN_BYTES_DEFAULT;
}
return 0;
}
/*
* Get a handle for a live capture from the given DAG device. The promisc
* flag is ignored because DAG cards are always promiscuous. The to_ms
* parameter is used in setting the API polling parameters.
*
* See also pcap(3).
*/
static int dag_activate(pcap_t* p)
{
struct pcap_dag *pd = p->priv;
char *s;
int n;
char * device = p->opt.device;
int ret;
dag_size_t mindata;
struct timeval maxwait;
struct timeval poll;
/*
* dag_create() has validated the device name syntax and stored the
* parsed device and stream numbers to p->priv. Validate these values
* semantically.
*/
if (pd->dag_devnum >= DAG_MAX_BOARDS) {
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
"DAG device number %d is too large", pd->dag_devnum);
ret = PCAP_ERROR_NO_SUCH_DEVICE;
goto fail;
}
if (pd->dag_stream >= DAG_STREAM_MAX) {
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
"DAG stream number %d is too large", pd->dag_stream);
ret = PCAP_ERROR_NO_SUCH_DEVICE;
goto fail;
}
#ifndef ENABLE_DAG_TX
if (TX_ONLY(pd->dag_stream)) {
/*
* dag_findalldevs() does not return any Tx streams, so
* PCAP_ERROR_NO_SUCH_DEVICE is more consistent than
* PCAP_ERROR_CAPTURE_NOTSUP.
*/
ret = PCAP_ERROR_NO_SUCH_DEVICE;
snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "%s: tx (odd numbered) streams not supported for capture", __func__);
goto fail;
}
#endif // ENABLE_DAG_TX
/* setup device parameters */
if((pd->dag_ref = dag_config_init(device)) == NULL) {
/*
* XXX - does this reliably set errno?
*/
if (errno == ENOENT) {
/*
* There's nothing more to say, so clear
* the error message.
*/
ret = PCAP_ERROR_NO_SUCH_DEVICE;
p->errbuf[0] = '\0';
} else if (errno == EPERM || errno == EACCES) {
ret = PCAP_ERROR_PERM_DENIED;
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
"Attempt to open %s failed with %s - additional privileges may be required",
device, (errno == EPERM) ? "EPERM" : "EACCES");
} else {
ret = PCAP_ERROR;
pcapint_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
errno, "dag_config_init %s", device);
}
goto fail;
}
if((p->fd = dag_config_get_card_fd(pd->dag_ref)) < 0) {
/*
* XXX - does this reliably set errno?
*/
ret = PCAP_ERROR;
pcapint_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
errno, "dag_config_get_card_fd %s", device);
goto failclose;
}
/* Open requested stream. Can fail if already locked or on error */
if (dag_attach_stream64(p->fd, pd->dag_stream, 0, 0) < 0) {
if (errno == ENOMEM) {
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
"dag%u has no memory allocated to %s stream %u",
pd->dag_devnum, RXTX_STR(pd->dag_stream), pd->dag_stream);
/*
* dag_findalldevs() does not return streams that do
* not have buffer memory, so PCAP_ERROR_NO_SUCH_DEVICE
* is more consistent than PCAP_ERROR_CAPTURE_NOTSUP.
*/
ret = PCAP_ERROR_NO_SUCH_DEVICE;
goto failclose;
} else if (errno == EINVAL) {
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
"dag%u has no %s stream %u",
pd->dag_devnum, RXTX_STR(pd->dag_stream), pd->dag_stream);
ret = PCAP_ERROR_NO_SUCH_DEVICE;
goto failclose;
}
ret = PCAP_ERROR;