xref: /freebsd/contrib/libpcap/pcap-dag.c (revision 42249ef2)
1 /*
2  * pcap-dag.c: Packet capture interface for Emulex EndaceDAG cards.
3  *
4  * The functionality of this code attempts to mimic that of pcap-linux as much
5  * as possible.  This code is compiled in several different ways depending on
6  * whether DAG_ONLY and HAVE_DAG_API are defined.  If HAVE_DAG_API is not
7  * defined it should not get compiled in, otherwise if DAG_ONLY is defined then
8  * the 'dag_' function calls are renamed to 'pcap_' equivalents.  If DAG_ONLY
9  * is not defined then nothing is altered - the dag_ functions will be
10  * called as required from their pcap-linux/bpf equivalents.
11  *
12  * Authors: Richard Littin, Sean Irvine ({richard,sean}@reeltwo.com)
13  * Modifications: Jesper Peterson
14  *                Koryn Grant
15  *                Stephen Donnelly <stephen.donnelly@emulex.com>
16  */
17 
18 #ifdef HAVE_CONFIG_H
19 #include <config.h>
20 #endif
21 
22 #include <sys/param.h>			/* optionally get BSD define */
23 
24 #include <stdlib.h>
25 #include <string.h>
26 #include <errno.h>
27 
28 #include "pcap-int.h"
29 
30 #include <ctype.h>
31 #include <netinet/in.h>
32 #include <sys/mman.h>
33 #include <sys/socket.h>
34 #include <sys/types.h>
35 #include <unistd.h>
36 
37 struct mbuf;		/* Squelch compiler warnings on some platforms for */
38 struct rtentry;		/* declarations in <net/if.h> */
39 #include <net/if.h>
40 
41 #include "dagnew.h"
42 #include "dagapi.h"
43 #include "dagpci.h"
44 #include "dag_config_api.h"
45 
46 #include "pcap-dag.h"
47 
48 /*
49  * DAG devices have names beginning with "dag", followed by a number
50  * from 0 to DAG_MAX_BOARDS, then optionally a colon and a stream number
51  * from 0 to DAG_STREAM_MAX.
52  */
53 #ifndef DAG_MAX_BOARDS
54 #define DAG_MAX_BOARDS 32
55 #endif
56 
57 
58 #ifndef ERF_TYPE_AAL5
59 #define ERF_TYPE_AAL5               4
60 #endif
61 
62 #ifndef ERF_TYPE_MC_HDLC
63 #define ERF_TYPE_MC_HDLC            5
64 #endif
65 
66 #ifndef ERF_TYPE_MC_RAW
67 #define ERF_TYPE_MC_RAW             6
68 #endif
69 
70 #ifndef ERF_TYPE_MC_ATM
71 #define ERF_TYPE_MC_ATM             7
72 #endif
73 
74 #ifndef ERF_TYPE_MC_RAW_CHANNEL
75 #define ERF_TYPE_MC_RAW_CHANNEL     8
76 #endif
77 
78 #ifndef ERF_TYPE_MC_AAL5
79 #define ERF_TYPE_MC_AAL5            9
80 #endif
81 
82 #ifndef ERF_TYPE_COLOR_HDLC_POS
83 #define ERF_TYPE_COLOR_HDLC_POS     10
84 #endif
85 
86 #ifndef ERF_TYPE_COLOR_ETH
87 #define ERF_TYPE_COLOR_ETH          11
88 #endif
89 
90 #ifndef ERF_TYPE_MC_AAL2
91 #define ERF_TYPE_MC_AAL2            12
92 #endif
93 
94 #ifndef ERF_TYPE_IP_COUNTER
95 #define ERF_TYPE_IP_COUNTER         13
96 #endif
97 
98 #ifndef ERF_TYPE_TCP_FLOW_COUNTER
99 #define ERF_TYPE_TCP_FLOW_COUNTER   14
100 #endif
101 
102 #ifndef ERF_TYPE_DSM_COLOR_HDLC_POS
103 #define ERF_TYPE_DSM_COLOR_HDLC_POS 15
104 #endif
105 
106 #ifndef ERF_TYPE_DSM_COLOR_ETH
107 #define ERF_TYPE_DSM_COLOR_ETH      16
108 #endif
109 
110 #ifndef ERF_TYPE_COLOR_MC_HDLC_POS
111 #define ERF_TYPE_COLOR_MC_HDLC_POS  17
112 #endif
113 
114 #ifndef ERF_TYPE_AAL2
115 #define ERF_TYPE_AAL2               18
116 #endif
117 
118 #ifndef ERF_TYPE_COLOR_HASH_POS
119 #define ERF_TYPE_COLOR_HASH_POS     19
120 #endif
121 
122 #ifndef ERF_TYPE_COLOR_HASH_ETH
123 #define ERF_TYPE_COLOR_HASH_ETH     20
124 #endif
125 
126 #ifndef ERF_TYPE_INFINIBAND
127 #define ERF_TYPE_INFINIBAND         21
128 #endif
129 
130 #ifndef ERF_TYPE_IPV4
131 #define ERF_TYPE_IPV4               22
132 #endif
133 
134 #ifndef ERF_TYPE_IPV6
135 #define ERF_TYPE_IPV6               23
136 #endif
137 
138 #ifndef ERF_TYPE_RAW_LINK
139 #define ERF_TYPE_RAW_LINK           24
140 #endif
141 
142 #ifndef ERF_TYPE_INFINIBAND_LINK
143 #define ERF_TYPE_INFINIBAND_LINK    25
144 #endif
145 
146 #ifndef ERF_TYPE_META
147 #define ERF_TYPE_META               27
148 #endif
149 
150 #ifndef ERF_TYPE_PAD
151 #define ERF_TYPE_PAD                48
152 #endif
153 
154 #define ATM_CELL_SIZE		52
155 #define ATM_HDR_SIZE		4
156 
157 /*
158  * A header containing additional MTP information.
159  */
160 #define MTP2_SENT_OFFSET		0	/* 1 byte */
161 #define MTP2_ANNEX_A_USED_OFFSET	1	/* 1 byte */
162 #define MTP2_LINK_NUMBER_OFFSET		2	/* 2 bytes */
163 #define MTP2_HDR_LEN			4	/* length of the header */
164 
165 #define MTP2_ANNEX_A_NOT_USED      0
166 #define MTP2_ANNEX_A_USED          1
167 #define MTP2_ANNEX_A_USED_UNKNOWN  2
168 
169 /* SunATM pseudo header */
170 struct sunatm_hdr {
171 	unsigned char	flags;		/* destination and traffic type */
172 	unsigned char	vpi;		/* VPI */
173 	unsigned short	vci;		/* VCI */
174 };
175 
176 /*
177  * Private data for capturing on DAG devices.
178  */
179 struct pcap_dag {
180 	struct pcap_stat stat;
181 	u_char	*dag_mem_bottom;	/* DAG card current memory bottom pointer */
182 	u_char	*dag_mem_top;	/* DAG card current memory top pointer */
183 	int	dag_fcs_bits;	/* Number of checksum bits from link layer */
184 	int	dag_flags;	/* Flags */
185 	int	dag_stream;	/* DAG stream number */
186 	int	dag_timeout;	/* timeout specified to pcap_open_live.
187 				 * Same as in linux above, introduce
188 				 * generally? */
189 	dag_card_ref_t dag_ref; /* DAG Configuration/Status API card reference */
190 	dag_component_t dag_root;	/* DAG CSAPI Root component */
191 	attr_uuid_t drop_attr;  /* DAG Stream Drop Attribute handle, if available */
192 	struct timeval required_select_timeout;
193 				/* Timeout caller must use in event loops */
194 };
195 
196 typedef struct pcap_dag_node {
197 	struct pcap_dag_node *next;
198 	pcap_t *p;
199 	pid_t pid;
200 } pcap_dag_node_t;
201 
202 static pcap_dag_node_t *pcap_dags = NULL;
203 static int atexit_handler_installed = 0;
204 static const unsigned short endian_test_word = 0x0100;
205 
206 #define IS_BIGENDIAN() (*((unsigned char *)&endian_test_word))
207 
208 #define MAX_DAG_PACKET 65536
209 
210 static unsigned char TempPkt[MAX_DAG_PACKET];
211 
212 #ifndef HAVE_DAG_LARGE_STREAMS_API
213 #define dag_attach_stream64(a, b, c, d) dag_attach_stream(a, b, c, d)
214 #define dag_get_stream_poll64(a, b, c, d, e) dag_get_stream_poll(a, b, c, d, e)
215 #define dag_set_stream_poll64(a, b, c, d, e) dag_set_stream_poll(a, b, c, d, e)
216 #define dag_size_t uint32_t
217 #endif
218 
219 static int dag_setfilter(pcap_t *p, struct bpf_program *fp);
220 static int dag_stats(pcap_t *p, struct pcap_stat *ps);
221 static int dag_set_datalink(pcap_t *p, int dlt);
222 static int dag_get_datalink(pcap_t *p);
223 static int dag_setnonblock(pcap_t *p, int nonblock);
224 
225 static void
226 delete_pcap_dag(pcap_t *p)
227 {
228 	pcap_dag_node_t *curr = NULL, *prev = NULL;
229 
230 	for (prev = NULL, curr = pcap_dags; curr != NULL && curr->p != p; prev = curr, curr = curr->next) {
231 		/* empty */
232 	}
233 
234 	if (curr != NULL && curr->p == p) {
235 		if (prev != NULL) {
236 			prev->next = curr->next;
237 		} else {
238 			pcap_dags = curr->next;
239 		}
240 	}
241 }
242 
243 /*
244  * Performs a graceful shutdown of the DAG card, frees dynamic memory held
245  * in the pcap_t structure, and closes the file descriptor for the DAG card.
246  */
247 
248 static void
249 dag_platform_cleanup(pcap_t *p)
250 {
251 	struct pcap_dag *pd = p->priv;
252 
253 	if(dag_stop_stream(p->fd, pd->dag_stream) < 0)
254 		fprintf(stderr,"dag_stop_stream: %s\n", strerror(errno));
255 
256 	if(dag_detach_stream(p->fd, pd->dag_stream) < 0)
257 		fprintf(stderr,"dag_detach_stream: %s\n", strerror(errno));
258 
259 	if(pd->dag_ref != NULL) {
260 		dag_config_dispose(pd->dag_ref);
261 		p->fd = -1;
262 		pd->dag_ref = NULL;
263 	}
264 	delete_pcap_dag(p);
265 	pcap_cleanup_live_common(p);
266 	/* Note: don't need to call close(p->fd) or dag_close(p->fd) as dag_config_dispose(pd->dag_ref) does this. */
267 }
268 
269 static void
270 atexit_handler(void)
271 {
272 	while (pcap_dags != NULL) {
273 		if (pcap_dags->pid == getpid()) {
274 			if (pcap_dags->p != NULL)
275 				dag_platform_cleanup(pcap_dags->p);
276 		} else {
277 			delete_pcap_dag(pcap_dags->p);
278 		}
279 	}
280 }
281 
282 static int
283 new_pcap_dag(pcap_t *p)
284 {
285 	pcap_dag_node_t *node = NULL;
286 
287 	if ((node = malloc(sizeof(pcap_dag_node_t))) == NULL) {
288 		return -1;
289 	}
290 
291 	if (!atexit_handler_installed) {
292 		atexit(atexit_handler);
293 		atexit_handler_installed = 1;
294 	}
295 
296 	node->next = pcap_dags;
297 	node->p = p;
298 	node->pid = getpid();
299 
300 	pcap_dags = node;
301 
302 	return 0;
303 }
304 
305 static unsigned int
306 dag_erf_ext_header_count(uint8_t * erf, size_t len)
307 {
308 	uint32_t hdr_num = 0;
309 	uint8_t  hdr_type;
310 
311 	/* basic sanity checks */
312 	if ( erf == NULL )
313 		return 0;
314 	if ( len < 16 )
315 		return 0;
316 
317 	/* check if we have any extension headers */
318 	if ( (erf[8] & 0x80) == 0x00 )
319 		return 0;
320 
321 	/* loop over the extension headers */
322 	do {
323 
324 		/* sanity check we have enough bytes */
325 		if ( len < (24 + (hdr_num * 8)) )
326 			return hdr_num;
327 
328 		/* get the header type */
329 		hdr_type = erf[(16 + (hdr_num * 8))];
330 		hdr_num++;
331 
332 	} while ( hdr_type & 0x80 );
333 
334 	return hdr_num;
335 }
336 
337 /*
338  *  Read at most max_packets from the capture stream and call the callback
339  *  for each of them. Returns the number of packets handled, -1 if an
340  *  error occured, or -2 if we were told to break out of the loop.
341  */
342 static int
343 dag_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
344 {
345 	struct pcap_dag *pd = p->priv;
346 	unsigned int processed = 0;
347 	unsigned int nonblocking = pd->dag_flags & DAGF_NONBLOCK;
348 	unsigned int num_ext_hdr = 0;
349 	unsigned int ticks_per_second;
350 
351 	/* Get the next bufferful of packets (if necessary). */
352 	while (pd->dag_mem_top - pd->dag_mem_bottom < dag_record_size) {
353 
354 		/*
355 		 * Has "pcap_breakloop()" been called?
356 		 */
357 		if (p->break_loop) {
358 			/*
359 			 * Yes - clear the flag that indicates that
360 			 * it has, and return -2 to indicate that
361 			 * we were told to break out of the loop.
362 			 */
363 			p->break_loop = 0;
364 			return -2;
365 		}
366 
367 		/* dag_advance_stream() will block (unless nonblock is called)
368 		 * until 64kB of data has accumulated.
369 		 * If to_ms is set, it will timeout before 64kB has accumulated.
370 		 * We wait for 64kB because processing a few packets at a time
371 		 * can cause problems at high packet rates (>200kpps) due
372 		 * to inefficiencies.
373 		 * This does mean if to_ms is not specified the capture may 'hang'
374 		 * for long periods if the data rate is extremely slow (<64kB/sec)
375 		 * If non-block is specified it will return immediately. The user
376 		 * is then responsible for efficiency.
377 		 */
378 		if ( NULL == (pd->dag_mem_top = dag_advance_stream(p->fd, pd->dag_stream, &(pd->dag_mem_bottom))) ) {
379 		     return -1;
380 		}
381 
382 		if (nonblocking && (pd->dag_mem_top - pd->dag_mem_bottom < dag_record_size))
383 		{
384 			/* Pcap is configured to process only available packets, and there aren't any, return immediately. */
385 			return 0;
386 		}
387 
388 		if(!nonblocking &&
389 		   pd->dag_timeout &&
390 		   (pd->dag_mem_top - pd->dag_mem_bottom < dag_record_size))
391 		{
392 			/* Blocking mode, but timeout set and no data has arrived, return anyway.*/
393 			return 0;
394 		}
395 
396 	}
397 
398 	/* Process the packets. */
399 	while (pd->dag_mem_top - pd->dag_mem_bottom >= dag_record_size) {
400 
401 		unsigned short packet_len = 0;
402 		int caplen = 0;
403 		struct pcap_pkthdr	pcap_header;
404 
405 		dag_record_t *header = (dag_record_t *)(pd->dag_mem_bottom);
406 
407 		u_char *dp = ((u_char *)header); /* + dag_record_size; */
408 		unsigned short rlen;
409 
410 		/*
411 		 * Has "pcap_breakloop()" been called?
412 		 */
413 		if (p->break_loop) {
414 			/*
415 			 * Yes - clear the flag that indicates that
416 			 * it has, and return -2 to indicate that
417 			 * we were told to break out of the loop.
418 			 */
419 			p->break_loop = 0;
420 			return -2;
421 		}
422 
423 		rlen = ntohs(header->rlen);
424 		if (rlen < dag_record_size)
425 		{
426 			strncpy(p->errbuf, "dag_read: record too small", PCAP_ERRBUF_SIZE);
427 			return -1;
428 		}
429 		pd->dag_mem_bottom += rlen;
430 
431 		/* Count lost packets. */
432 		switch((header->type & 0x7f)) {
433 			/* in these types the color value overwrites the lctr */
434 		case ERF_TYPE_COLOR_HDLC_POS:
435 		case ERF_TYPE_COLOR_ETH:
436 		case ERF_TYPE_DSM_COLOR_HDLC_POS:
437 		case ERF_TYPE_DSM_COLOR_ETH:
438 		case ERF_TYPE_COLOR_MC_HDLC_POS:
439 		case ERF_TYPE_COLOR_HASH_ETH:
440 		case ERF_TYPE_COLOR_HASH_POS:
441 			break;
442 
443 		default:
444 			if ( (pd->drop_attr == kNullAttributeUuid) && (header->lctr) ) {
445 				pd->stat.ps_drop += ntohs(header->lctr);
446 			}
447 		}
448 
449 		if ((header->type & 0x7f) == ERF_TYPE_PAD) {
450 			continue;
451 		}
452 
453 		num_ext_hdr = dag_erf_ext_header_count(dp, rlen);
454 
455 		/* ERF encapsulation */
456 		/* The Extensible Record Format is not dropped for this kind of encapsulation,
457 		 * and will be handled as a pseudo header by the decoding application.
458 		 * The information carried in the ERF header and in the optional subheader (if present)
459 		 * could be merged with the libpcap information, to offer a better decoding.
460 		 * The packet length is
461 		 * o the length of the packet on the link (header->wlen),
462 		 * o plus the length of the ERF header (dag_record_size), as the length of the
463 		 *   pseudo header will be adjusted during the decoding,
464 		 * o plus the length of the optional subheader (if present).
465 		 *
466 		 * The capture length is header.rlen and the byte stuffing for alignment will be dropped
467 		 * if the capture length is greater than the packet length.
468 		 */
469 		if (p->linktype == DLT_ERF) {
470 			packet_len = ntohs(header->wlen) + dag_record_size;
471 			caplen = rlen;
472 			switch ((header->type & 0x7f)) {
473 			case ERF_TYPE_MC_AAL5:
474 			case ERF_TYPE_MC_ATM:
475 			case ERF_TYPE_MC_HDLC:
476 			case ERF_TYPE_MC_RAW_CHANNEL:
477 			case ERF_TYPE_MC_RAW:
478 			case ERF_TYPE_MC_AAL2:
479 			case ERF_TYPE_COLOR_MC_HDLC_POS:
480 				packet_len += 4; /* MC header */
481 				break;
482 
483 			case ERF_TYPE_COLOR_HASH_ETH:
484 			case ERF_TYPE_DSM_COLOR_ETH:
485 			case ERF_TYPE_COLOR_ETH:
486 			case ERF_TYPE_ETH:
487 				packet_len += 2; /* ETH header */
488 				break;
489 			} /* switch type */
490 
491 			/* Include ERF extension headers */
492 			packet_len += (8 * num_ext_hdr);
493 
494 			if (caplen > packet_len) {
495 				caplen = packet_len;
496 			}
497 		} else {
498 			/* Other kind of encapsulation according to the header Type */
499 
500 			/* Skip over generic ERF header */
501 			dp += dag_record_size;
502 			/* Skip over extension headers */
503 			dp += 8 * num_ext_hdr;
504 
505 			switch((header->type & 0x7f)) {
506 			case ERF_TYPE_ATM:
507 			case ERF_TYPE_AAL5:
508 				if ((header->type & 0x7f) == ERF_TYPE_AAL5) {
509 					packet_len = ntohs(header->wlen);
510 					caplen = rlen - dag_record_size;
511 				}
512 			case ERF_TYPE_MC_ATM:
513 				if ((header->type & 0x7f) == ERF_TYPE_MC_ATM) {
514 					caplen = packet_len = ATM_CELL_SIZE;
515 					dp+=4;
516 				}
517 			case ERF_TYPE_MC_AAL5:
518 				if ((header->type & 0x7f) == ERF_TYPE_MC_AAL5) {
519 					packet_len = ntohs(header->wlen);
520 					caplen = rlen - dag_record_size - 4;
521 					dp+=4;
522 				}
523 				/* Skip over extension headers */
524 				caplen -= (8 * num_ext_hdr);
525 
526 				if ((header->type & 0x7f) == ERF_TYPE_ATM) {
527 					caplen = packet_len = ATM_CELL_SIZE;
528 				}
529 				if (p->linktype == DLT_SUNATM) {
530 					struct sunatm_hdr *sunatm = (struct sunatm_hdr *)dp;
531 					unsigned long rawatm;
532 
533 					rawatm = ntohl(*((unsigned long *)dp));
534 					sunatm->vci = htons((rawatm >>  4) & 0xffff);
535 					sunatm->vpi = (rawatm >> 20) & 0x00ff;
536 					sunatm->flags = ((header->flags.iface & 1) ? 0x80 : 0x00) |
537 						((sunatm->vpi == 0 && sunatm->vci == htons(5)) ? 6 :
538 						 ((sunatm->vpi == 0 && sunatm->vci == htons(16)) ? 5 :
539 						  ((dp[ATM_HDR_SIZE] == 0xaa &&
540 						    dp[ATM_HDR_SIZE+1] == 0xaa &&
541 						    dp[ATM_HDR_SIZE+2] == 0x03) ? 2 : 1)));
542 
543 				} else if (p->linktype == DLT_ATM_RFC1483) {
544 					packet_len -= ATM_HDR_SIZE;
545 					caplen -= ATM_HDR_SIZE;
546 					dp += ATM_HDR_SIZE;
547 				} else
548 					continue;
549 				break;
550 
551 			case ERF_TYPE_COLOR_HASH_ETH:
552 			case ERF_TYPE_DSM_COLOR_ETH:
553 			case ERF_TYPE_COLOR_ETH:
554 			case ERF_TYPE_ETH:
555 				if ((p->linktype != DLT_EN10MB) &&
556 				    (p->linktype != DLT_DOCSIS))
557 					continue;
558 				packet_len = ntohs(header->wlen);
559 				packet_len -= (pd->dag_fcs_bits >> 3);
560 				caplen = rlen - dag_record_size - 2;
561 				/* Skip over extension headers */
562 				caplen -= (8 * num_ext_hdr);
563 				if (caplen > packet_len) {
564 					caplen = packet_len;
565 				}
566 				dp += 2;
567 				break;
568 
569 			case ERF_TYPE_COLOR_HASH_POS:
570 			case ERF_TYPE_DSM_COLOR_HDLC_POS:
571 			case ERF_TYPE_COLOR_HDLC_POS:
572 			case ERF_TYPE_HDLC_POS:
573 				if ((p->linktype != DLT_CHDLC) &&
574 				    (p->linktype != DLT_PPP_SERIAL) &&
575 				    (p->linktype != DLT_FRELAY))
576 					continue;
577 				packet_len = ntohs(header->wlen);
578 				packet_len -= (pd->dag_fcs_bits >> 3);
579 				caplen = rlen - dag_record_size;
580 				/* Skip over extension headers */
581 				caplen -= (8 * num_ext_hdr);
582 				if (caplen > packet_len) {
583 					caplen = packet_len;
584 				}
585 				break;
586 
587 			case ERF_TYPE_COLOR_MC_HDLC_POS:
588 			case ERF_TYPE_MC_HDLC:
589 				if ((p->linktype != DLT_CHDLC) &&
590 				    (p->linktype != DLT_PPP_SERIAL) &&
591 				    (p->linktype != DLT_FRELAY) &&
592 				    (p->linktype != DLT_MTP2) &&
593 				    (p->linktype != DLT_MTP2_WITH_PHDR) &&
594 				    (p->linktype != DLT_LAPD))
595 					continue;
596 				packet_len = ntohs(header->wlen);
597 				packet_len -= (pd->dag_fcs_bits >> 3);
598 				caplen = rlen - dag_record_size - 4;
599 				/* Skip over extension headers */
600 				caplen -= (8 * num_ext_hdr);
601 				if (caplen > packet_len) {
602 					caplen = packet_len;
603 				}
604 				/* jump the MC_HDLC_HEADER */
605 				dp += 4;
606 #ifdef DLT_MTP2_WITH_PHDR
607 				if (p->linktype == DLT_MTP2_WITH_PHDR) {
608 					/* Add the MTP2 Pseudo Header */
609 					caplen += MTP2_HDR_LEN;
610 					packet_len += MTP2_HDR_LEN;
611 
612 					TempPkt[MTP2_SENT_OFFSET] = 0;
613 					TempPkt[MTP2_ANNEX_A_USED_OFFSET] = MTP2_ANNEX_A_USED_UNKNOWN;
614 					*(TempPkt+MTP2_LINK_NUMBER_OFFSET) = ((header->rec.mc_hdlc.mc_header>>16)&0x01);
615 					*(TempPkt+MTP2_LINK_NUMBER_OFFSET+1) = ((header->rec.mc_hdlc.mc_header>>24)&0xff);
616 					memcpy(TempPkt+MTP2_HDR_LEN, dp, caplen);
617 					dp = TempPkt;
618 				}
619 #endif
620 				break;
621 
622 			case ERF_TYPE_IPV4:
623 				if ((p->linktype != DLT_RAW) &&
624 				    (p->linktype != DLT_IPV4))
625 					continue;
626 				packet_len = ntohs(header->wlen);
627 				caplen = rlen - dag_record_size;
628 				/* Skip over extension headers */
629 				caplen -= (8 * num_ext_hdr);
630 				if (caplen > packet_len) {
631 					caplen = packet_len;
632 				}
633 				break;
634 
635 			case ERF_TYPE_IPV6:
636 				if ((p->linktype != DLT_RAW) &&
637 				    (p->linktype != DLT_IPV6))
638 					continue;
639 				packet_len = ntohs(header->wlen);
640 				caplen = rlen - dag_record_size;
641 				/* Skip over extension headers */
642 				caplen -= (8 * num_ext_hdr);
643 				if (caplen > packet_len) {
644 					caplen = packet_len;
645 				}
646 				break;
647 
648 			/* These types have no matching 'native' DLT, but can be used with DLT_ERF above */
649 			case ERF_TYPE_MC_RAW:
650 			case ERF_TYPE_MC_RAW_CHANNEL:
651 			case ERF_TYPE_IP_COUNTER:
652 			case ERF_TYPE_TCP_FLOW_COUNTER:
653 			case ERF_TYPE_INFINIBAND:
654 			case ERF_TYPE_RAW_LINK:
655 			case ERF_TYPE_INFINIBAND_LINK:
656 			default:
657 				/* Unhandled ERF type.
658 				 * Ignore rather than generating error
659 				 */
660 				continue;
661 			} /* switch type */
662 
663 		} /* ERF encapsulation */
664 
665 		if (caplen > p->snapshot)
666 			caplen = p->snapshot;
667 
668 		/* Run the packet filter if there is one. */
669 		if ((p->fcode.bf_insns == NULL) || bpf_filter(p->fcode.bf_insns, dp, packet_len, caplen)) {
670 
671 			/* convert between timestamp formats */
672 			register unsigned long long ts;
673 
674 			if (IS_BIGENDIAN()) {
675 				ts = SWAPLL(header->ts);
676 			} else {
677 				ts = header->ts;
678 			}
679 
680 			switch (p->opt.tstamp_precision) {
681 			case PCAP_TSTAMP_PRECISION_NANO:
682 				ticks_per_second = 1000000000;
683 				break;
684 			case PCAP_TSTAMP_PRECISION_MICRO:
685 			default:
686 				ticks_per_second = 1000000;
687 				break;
688 
689 			}
690 			pcap_header.ts.tv_sec = ts >> 32;
691 			ts = (ts & 0xffffffffULL) * ticks_per_second;
692 			ts += 0x80000000; /* rounding */
693 			pcap_header.ts.tv_usec = ts >> 32;
694 			if (pcap_header.ts.tv_usec >= ticks_per_second) {
695 				pcap_header.ts.tv_usec -= ticks_per_second;
696 				pcap_header.ts.tv_sec++;
697 			}
698 
699 			/* Fill in our own header data */
700 			pcap_header.caplen = caplen;
701 			pcap_header.len = packet_len;
702 
703 			/* Count the packet. */
704 			pd->stat.ps_recv++;
705 
706 			/* Call the user supplied callback function */
707 			callback(user, &pcap_header, dp);
708 
709 			/* Only count packets that pass the filter, for consistency with standard Linux behaviour. */
710 			processed++;
711 			if (processed == cnt && !PACKET_COUNT_IS_UNLIMITED(cnt))
712 			{
713 				/* Reached the user-specified limit. */
714 				return cnt;
715 			}
716 		}
717 	}
718 
719 	return processed;
720 }
721 
722 static int
723 dag_inject(pcap_t *p, const void *buf _U_, size_t size _U_)
724 {
725 	strlcpy(p->errbuf, "Sending packets isn't supported on DAG cards",
726 	    PCAP_ERRBUF_SIZE);
727 	return (-1);
728 }
729 
730 /*
731  *  Get a handle for a live capture from the given DAG device.  Passing a NULL
732  *  device will result in a failure.  The promisc flag is ignored because DAG
733  *  cards are always promiscuous.  The to_ms parameter is used in setting the
734  *  API polling parameters.
735  *
736  *  snaplen is now also ignored, until we get per-stream slen support. Set
737  *  slen with approprite DAG tool BEFORE pcap_activate().
738  *
739  *  See also pcap(3).
740  */
741 static int dag_activate(pcap_t* p)
742 {
743 	struct pcap_dag *pd = p->priv;
744 	char *s;
745 	int n;
746 	daginf_t* daginf;
747 	char * newDev = NULL;
748 	char * device = p->opt.device;
749 	dag_size_t mindata;
750 	struct timeval maxwait;
751 	struct timeval poll;
752 
753 	if (device == NULL) {
754 		pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "device is NULL");
755 		return -1;
756 	}
757 
758 	/* Initialize some components of the pcap structure. */
759 	newDev = (char *)malloc(strlen(device) + 16);
760 	if (newDev == NULL) {
761 		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
762 		    errno, "Can't allocate string for device name");
763 		goto fail;
764 	}
765 
766 	/* Parse input name to get dag device and stream number if provided */
767 	if (dag_parse_name(device, newDev, strlen(device) + 16, &pd->dag_stream) < 0) {
768 		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
769 		    errno, "dag_parse_name");
770 		goto fail;
771 	}
772 	device = newDev;
773 
774 	if (pd->dag_stream%2) {
775 		pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "dag_parse_name: tx (even numbered) streams not supported for capture");
776 		goto fail;
777 	}
778 
779 	/* setup device parameters */
780 	if((pd->dag_ref = dag_config_init((char *)device)) == NULL) {
781 		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
782 		    errno, "dag_config_init %s", device);
783 		goto fail;
784 	}
785 
786 	if((p->fd = dag_config_get_card_fd(pd->dag_ref)) < 0) {
787 		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
788 		    errno, "dag_config_get_card_fd %s", device);
789 		goto fail;
790 	}
791 
792 	/* Open requested stream. Can fail if already locked or on error */
793 	if (dag_attach_stream64(p->fd, pd->dag_stream, 0, 0) < 0) {
794 		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
795 		    errno, "dag_attach_stream");
796 		goto failclose;
797 	}
798 
799 	/* Try to find Stream Drop attribute */
800 	pd->drop_attr = kNullAttributeUuid;
801 	pd->dag_root = dag_config_get_root_component(pd->dag_ref);
802 	if ( dag_component_get_subcomponent(pd->dag_root, kComponentStreamFeatures, 0) )
803 	{
804 		pd->drop_attr = dag_config_get_indexed_attribute_uuid(pd->dag_ref, kUint32AttributeStreamDropCount, pd->dag_stream/2);
805 	}
806 
807 	/* Set up default poll parameters for stream
808 	 * Can be overridden by pcap_set_nonblock()
809 	 */
810 	if (dag_get_stream_poll64(p->fd, pd->dag_stream,
811 				&mindata, &maxwait, &poll) < 0) {
812 		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
813 		    errno, "dag_get_stream_poll");
814 		goto faildetach;
815 	}
816 
817 	/* Use the poll time as the required select timeout for callers
818 	 * who are using select()/etc. in an event loop waiting for
819 	 * packets to arrive.
820 	 */
821 	pd->required_select_timeout = poll;
822 	p->required_select_timeout = &pd->required_select_timeout;
823 
824 	/*
825 	 * Turn a negative snapshot value (invalid), a snapshot value of
826 	 * 0 (unspecified), or a value bigger than the normal maximum
827 	 * value, into the maximum allowed value.
828 	 *
829 	 * If some application really *needs* a bigger snapshot
830 	 * length, we should just increase MAXIMUM_SNAPLEN.
831 	 */
832 	if (p->snapshot <= 0 || p->snapshot > MAXIMUM_SNAPLEN)
833 		p->snapshot = MAXIMUM_SNAPLEN;
834 
835 	if (p->opt.immediate) {
836 		/* Call callback immediately.
837 		 * XXX - is this the right way to p this?
838 		 */
839 		mindata = 0;
840 	} else {
841 		/* Amount of data to collect in Bytes before calling callbacks.
842 		 * Important for efficiency, but can introduce latency
843 		 * at low packet rates if to_ms not set!
844 		 */
845 		mindata = 65536;
846 	}
847 
848 	/* Obey opt.timeout (was to_ms) if supplied. This is a good idea!
849 	 * Recommend 10-100ms. Calls will time out even if no data arrived.
850 	 */
851 	maxwait.tv_sec = p->opt.timeout/1000;
852 	maxwait.tv_usec = (p->opt.timeout%1000) * 1000;
853 
854 	if (dag_set_stream_poll64(p->fd, pd->dag_stream,
855 				mindata, &maxwait, &poll) < 0) {
856 		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
857 		    errno, "dag_set_stream_poll");
858 		goto faildetach;
859 	}
860 
861         /* XXX Not calling dag_configure() to set slen; this is unsafe in
862 	 * multi-stream environments as the gpp config is global.
863          * Once the firmware provides 'per-stream slen' this can be supported
864 	 * again via the Config API without side-effects */
865 #if 0
866 	/* set the card snap length to the specified snaplen parameter */
867 	/* This is a really bad idea, as different cards have different
868 	 * valid slen ranges. Should fix in Config API. */
869 	if (p->snapshot == 0 || p->snapshot > MAX_DAG_SNAPLEN) {
870 		p->snapshot = MAX_DAG_SNAPLEN;
871 	} else if (snaplen < MIN_DAG_SNAPLEN) {
872 		p->snapshot = MIN_DAG_SNAPLEN;
873 	}
874 	/* snap len has to be a multiple of 4 */
875 #endif
876 
877 	if(dag_start_stream(p->fd, pd->dag_stream) < 0) {
878 		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
879 		    errno, "dag_start_stream %s", device);
880 		goto faildetach;
881 	}
882 
883 	/*
884 	 * Important! You have to ensure bottom is properly
885 	 * initialized to zero on startup, it won't give you
886 	 * a compiler warning if you make this mistake!
887 	 */
888 	pd->dag_mem_bottom = 0;
889 	pd->dag_mem_top = 0;
890 
891 	/*
892 	 * Find out how many FCS bits we should strip.
893 	 * First, query the card to see if it strips the FCS.
894 	 */
895 	daginf = dag_info(p->fd);
896 	if ((0x4200 == daginf->device_code) || (0x4230 == daginf->device_code))	{
897 		/* DAG 4.2S and 4.23S already strip the FCS.  Stripping the final word again truncates the packet. */
898 		pd->dag_fcs_bits = 0;
899 
900 		/* Note that no FCS will be supplied. */
901 		p->linktype_ext = LT_FCS_DATALINK_EXT(0);
902 	} else {
903 		/*
904 		 * Start out assuming it's 32 bits.
905 		 */
906 		pd->dag_fcs_bits = 32;
907 
908 		/* Allow an environment variable to override. */
909 		if ((s = getenv("ERF_FCS_BITS")) != NULL) {
910 			if ((n = atoi(s)) == 0 || n == 16 || n == 32) {
911 				pd->dag_fcs_bits = n;
912 			} else {
913 				pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
914 					"pcap_activate %s: bad ERF_FCS_BITS value (%d) in environment", device, n);
915 				goto failstop;
916 			}
917 		}
918 
919 		/*
920 		 * Did the user request that they not be stripped?
921 		 */
922 		if ((s = getenv("ERF_DONT_STRIP_FCS")) != NULL) {
923 			/* Yes.  Note the number of bytes that will be
924 			   supplied. */
925 			p->linktype_ext = LT_FCS_DATALINK_EXT(pd->dag_fcs_bits/16);
926 
927 			/* And don't strip them. */
928 			pd->dag_fcs_bits = 0;
929 		}
930 	}
931 
932 	pd->dag_timeout	= p->opt.timeout;
933 
934 	p->linktype = -1;
935 	if (dag_get_datalink(p) < 0)
936 		goto failstop;
937 
938 	p->bufsize = 0;
939 
940 	if (new_pcap_dag(p) < 0) {
941 		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
942 		    errno, "new_pcap_dag %s", device);
943 		goto failstop;
944 	}
945 
946 	/*
947 	 * "select()" and "poll()" don't work on DAG device descriptors.
948 	 */
949 	p->selectable_fd = -1;
950 
951 	if (newDev != NULL) {
952 		free((char *)newDev);
953 	}
954 
955 	p->read_op = dag_read;
956 	p->inject_op = dag_inject;
957 	p->setfilter_op = dag_setfilter;
958 	p->setdirection_op = NULL; /* Not implemented.*/
959 	p->set_datalink_op = dag_set_datalink;
960 	p->getnonblock_op = pcap_getnonblock_fd;
961 	p->setnonblock_op = dag_setnonblock;
962 	p->stats_op = dag_stats;
963 	p->cleanup_op = dag_platform_cleanup;
964 	pd->stat.ps_drop = 0;
965 	pd->stat.ps_recv = 0;
966 	pd->stat.ps_ifdrop = 0;
967 	return 0;
968 
969 failstop:
970 	if (dag_stop_stream(p->fd, pd->dag_stream) < 0) {
971 		fprintf(stderr,"dag_stop_stream: %s\n", strerror(errno));
972 	}
973 
974 faildetach:
975 	if (dag_detach_stream(p->fd, pd->dag_stream) < 0)
976 		fprintf(stderr,"dag_detach_stream: %s\n", strerror(errno));
977 
978 failclose:
979 	dag_config_dispose(pd->dag_ref);
980 	delete_pcap_dag(p);
981 
982 fail:
983 	pcap_cleanup_live_common(p);
984 	if (newDev != NULL) {
985 		free((char *)newDev);
986 	}
987 
988 	return PCAP_ERROR;
989 }
990 
991 pcap_t *dag_create(const char *device, char *ebuf, int *is_ours)
992 {
993 	const char *cp;
994 	char *cpend;
995 	long devnum;
996 	pcap_t *p;
997 	long stream = 0;
998 
999 	/* Does this look like a DAG device? */
1000 	cp = strrchr(device, '/');
1001 	if (cp == NULL)
1002 		cp = device;
1003 	/* Does it begin with "dag"? */
1004 	if (strncmp(cp, "dag", 3) != 0) {
1005 		/* Nope, doesn't begin with "dag" */
1006 		*is_ours = 0;
1007 		return NULL;
1008 	}
1009 	/* Yes - is "dag" followed by a number from 0 to DAG_MAX_BOARDS-1 */
1010 	cp += 3;
1011 	devnum = strtol(cp, &cpend, 10);
1012 	if (*cpend == ':') {
1013 		/* Followed by a stream number. */
1014 		stream = strtol(++cpend, &cpend, 10);
1015 	}
1016 
1017 	if (cpend == cp || *cpend != '\0') {
1018 		/* Not followed by a number. */
1019 		*is_ours = 0;
1020 		return NULL;
1021 	}
1022 
1023 	if (devnum < 0 || devnum >= DAG_MAX_BOARDS) {
1024 		/* Followed by a non-valid number. */
1025 		*is_ours = 0;
1026 		return NULL;
1027 	}
1028 
1029 	if (stream <0 || stream >= DAG_STREAM_MAX) {
1030 		/* Followed by a non-valid stream number. */
1031 		*is_ours = 0;
1032 		return NULL;
1033 	}
1034 
1035 	/* OK, it's probably ours. */
1036 	*is_ours = 1;
1037 
1038 	p = pcap_create_common(ebuf, sizeof (struct pcap_dag));
1039 	if (p == NULL)
1040 		return NULL;
1041 
1042 	p->activate_op = dag_activate;
1043 
1044 	/*
1045 	 * We claim that we support microsecond and nanosecond time
1046 	 * stamps.
1047 	 *
1048 	 * XXX Our native precision is 2^-32s, but libpcap doesn't support
1049 	 * power of two precisions yet. We can convert to either MICRO or NANO.
1050 	 */
1051 	p->tstamp_precision_count = 2;
1052 	p->tstamp_precision_list = malloc(2 * sizeof(u_int));
1053 	if (p->tstamp_precision_list == NULL) {
1054 		pcap_fmt_errmsg_for_errno(ebuf, PCAP_ERRBUF_SIZE,
1055 		    errno, "malloc");
1056 		pcap_close(p);
1057 		return NULL;
1058 	}
1059 	p->tstamp_precision_list[0] = PCAP_TSTAMP_PRECISION_MICRO;
1060 	p->tstamp_precision_list[1] = PCAP_TSTAMP_PRECISION_NANO;
1061 	return p;
1062 }
1063 
1064 static int
1065 dag_stats(pcap_t *p, struct pcap_stat *ps) {
1066 	struct pcap_dag *pd = p->priv;
1067 	uint32_t stream_drop;
1068 	dag_err_t dag_error;
1069 
1070 	/*
1071 	 * Packet records received (ps_recv) are counted in dag_read().
1072 	 * Packet records dropped (ps_drop) are read from Stream Drop attribute if present,
1073 	 * otherwise integrate the ERF Header lctr counts (if available) in dag_read().
1074 	 * We are reporting that no records are dropped by the card/driver (ps_ifdrop).
1075 	 */
1076 
1077 	if(pd->drop_attr != kNullAttributeUuid) {
1078 		/* Note this counter is cleared at start of capture and will wrap at UINT_MAX.
1079 		 * The application is responsible for polling ps_drop frequently enough
1080 		 * to detect each wrap and integrate total drop with a wider counter */
1081 		if ((dag_error = dag_config_get_uint32_attribute_ex(pd->dag_ref, pd->drop_attr, &stream_drop) == kDagErrNone)) {
1082 			pd->stat.ps_drop = stream_drop;
1083 		} else {
1084 			pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "reading stream drop attribute: %s",
1085 				 dag_config_strerror(dag_error));
1086 			return -1;
1087 		}
1088 	}
1089 
1090 	*ps = pd->stat;
1091 
1092 	return 0;
1093 }
1094 
1095 /*
1096  * Add all DAG devices.
1097  */
1098 int
1099 dag_findalldevs(pcap_if_list_t *devlistp, char *errbuf)
1100 {
1101 	char name[12];	/* XXX - pick a size */
1102 	int c;
1103 	char dagname[DAGNAME_BUFSIZE];
1104 	int dagstream;
1105 	int dagfd;
1106 	dag_card_inf_t *inf;
1107 	char *description;
1108 	int stream, rxstreams;
1109 
1110 	/* Try all the DAGs 0-DAG_MAX_BOARDS */
1111 	for (c = 0; c < DAG_MAX_BOARDS; c++) {
1112 		pcap_snprintf(name, 12, "dag%d", c);
1113 		if (-1 == dag_parse_name(name, dagname, DAGNAME_BUFSIZE, &dagstream))
1114 		{
1115 			(void) pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
1116 			    "dag: device name %s can't be parsed", name);
1117 			return (-1);
1118 		}
1119 		if ( (dagfd = dag_open(dagname)) >= 0 ) {
1120 			description = NULL;
1121 			if ((inf = dag_pciinfo(dagfd)))
1122 				description = dag_device_name(inf->device_code, 1);
1123 			/*
1124 			 * XXX - is there a way to determine whether
1125 			 * the card is plugged into a network or not?
1126 			 * If so, we should check that and set
1127 			 * PCAP_IF_CONNECTION_STATUS_CONNECTED or
1128 			 * PCAP_IF_CONNECTION_STATUS_DISCONNECTED.
1129 			 *
1130 			 * Also, are there notions of "up" and "running"?
1131 			 */
1132 			if (add_dev(devlistp, name, 0, description, errbuf) == NULL) {
1133 				/*
1134 				 * Failure.
1135 				 */
1136 				return (-1);
1137 			}
1138 			rxstreams = dag_rx_get_stream_count(dagfd);
1139 			for(stream=0;stream<DAG_STREAM_MAX;stream+=2) {
1140 				if (0 == dag_attach_stream(dagfd, stream, 0, 0)) {
1141 					dag_detach_stream(dagfd, stream);
1142 
1143 					pcap_snprintf(name,  10, "dag%d:%d", c, stream);
1144 					if (add_dev(devlistp, name, 0, description, errbuf) == NULL) {
1145 						/*
1146 						 * Failure.
1147 						 */
1148 						return (-1);
1149 					}
1150 
1151 					rxstreams--;
1152 					if(rxstreams <= 0) {
1153 						break;
1154 					}
1155 				}
1156 			}
1157 			dag_close(dagfd);
1158 		}
1159 
1160 	}
1161 	return (0);
1162 }
1163 
1164 /*
1165  * Installs the given bpf filter program in the given pcap structure.  There is
1166  * no attempt to store the filter in kernel memory as that is not supported
1167  * with DAG cards.
1168  */
1169 static int
1170 dag_setfilter(pcap_t *p, struct bpf_program *fp)
1171 {
1172 	if (!p)
1173 		return -1;
1174 	if (!fp) {
1175 		strncpy(p->errbuf, "setfilter: No filter specified",
1176 			sizeof(p->errbuf));
1177 		return -1;
1178 	}
1179 
1180 	/* Make our private copy of the filter */
1181 
1182 	if (install_bpf_program(p, fp) < 0)
1183 		return -1;
1184 
1185 	return (0);
1186 }
1187 
1188 static int
1189 dag_set_datalink(pcap_t *p, int dlt)
1190 {
1191 	p->linktype = dlt;
1192 
1193 	return (0);
1194 }
1195 
1196 static int
1197 dag_setnonblock(pcap_t *p, int nonblock)
1198 {
1199 	struct pcap_dag *pd = p->priv;
1200 	dag_size_t mindata;
1201 	struct timeval maxwait;
1202 	struct timeval poll;
1203 
1204 	/*
1205 	 * Set non-blocking mode on the FD.
1206 	 * XXX - is that necessary?  If not, don't bother calling it,
1207 	 * and have a "dag_getnonblock()" function that looks at
1208 	 * "pd->dag_flags".
1209 	 */
1210 	if (pcap_setnonblock_fd(p, nonblock) < 0)
1211 		return (-1);
1212 
1213 	if (dag_get_stream_poll64(p->fd, pd->dag_stream,
1214 				&mindata, &maxwait, &poll) < 0) {
1215 		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
1216 		    errno, "dag_get_stream_poll");
1217 		return -1;
1218 	}
1219 
1220 	/* Amount of data to collect in Bytes before calling callbacks.
1221 	 * Important for efficiency, but can introduce latency
1222 	 * at low packet rates if to_ms not set!
1223 	 */
1224 	if(nonblock)
1225 		mindata = 0;
1226 	else
1227 		mindata = 65536;
1228 
1229 	if (dag_set_stream_poll64(p->fd, pd->dag_stream,
1230 				mindata, &maxwait, &poll) < 0) {
1231 		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
1232 		    errno, "dag_set_stream_poll");
1233 		return -1;
1234 	}
1235 
1236 	if (nonblock) {
1237 		pd->dag_flags |= DAGF_NONBLOCK;
1238 	} else {
1239 		pd->dag_flags &= ~DAGF_NONBLOCK;
1240 	}
1241 	return (0);
1242 }
1243 
1244 static int
1245 dag_get_datalink(pcap_t *p)
1246 {
1247 	struct pcap_dag *pd = p->priv;
1248 	int index=0, dlt_index=0;
1249 	uint8_t types[255];
1250 
1251 	memset(types, 0, 255);
1252 
1253 	if (p->dlt_list == NULL && (p->dlt_list = malloc(255*sizeof(*(p->dlt_list)))) == NULL) {
1254 		pcap_fmt_errmsg_for_errno(p->errbuf, sizeof(p->errbuf),
1255 		    errno, "malloc");
1256 		return (-1);
1257 	}
1258 
1259 	p->linktype = 0;
1260 
1261 #ifdef HAVE_DAG_GET_STREAM_ERF_TYPES
1262 	/* Get list of possible ERF types for this card */
1263 	if (dag_get_stream_erf_types(p->fd, pd->dag_stream, types, 255) < 0) {
1264 		pcap_fmt_errmsg_for_errno(p->errbuf, sizeof(p->errbuf),
1265 		    errno, "dag_get_stream_erf_types");
1266 		return (-1);
1267 	}
1268 
1269 	while (types[index]) {
1270 
1271 #elif defined HAVE_DAG_GET_ERF_TYPES
1272 	/* Get list of possible ERF types for this card */
1273 	if (dag_get_erf_types(p->fd, types, 255) < 0) {
1274 		pcap_fmt_errmsg_for_errno(p->errbuf, sizeof(p->errbuf),
1275 		    errno, "dag_get_erf_types");
1276 		return (-1);
1277 	}
1278 
1279 	while (types[index]) {
1280 #else
1281 	/* Check the type through a dagapi call. */
1282 	types[index] = dag_linktype(p->fd);
1283 
1284 	{
1285 #endif
1286 		switch((types[index] & 0x7f)) {
1287 
1288 		case ERF_TYPE_HDLC_POS:
1289 		case ERF_TYPE_COLOR_HDLC_POS:
1290 		case ERF_TYPE_DSM_COLOR_HDLC_POS:
1291 		case ERF_TYPE_COLOR_HASH_POS:
1292 
1293 			if (p->dlt_list != NULL) {
1294 				p->dlt_list[dlt_index++] = DLT_CHDLC;
1295 				p->dlt_list[dlt_index++] = DLT_PPP_SERIAL;
1296 				p->dlt_list[dlt_index++] = DLT_FRELAY;
1297 			}
1298 			if(!p->linktype)
1299 				p->linktype = DLT_CHDLC;
1300 			break;
1301 
1302 		case ERF_TYPE_ETH:
1303 		case ERF_TYPE_COLOR_ETH:
1304 		case ERF_TYPE_DSM_COLOR_ETH:
1305 		case ERF_TYPE_COLOR_HASH_ETH:
1306 			/*
1307 			 * This is (presumably) a real Ethernet capture; give it a
1308 			 * link-layer-type list with DLT_EN10MB and DLT_DOCSIS, so
1309 			 * that an application can let you choose it, in case you're
1310 			 * capturing DOCSIS traffic that a Cisco Cable Modem
1311 			 * Termination System is putting out onto an Ethernet (it
1312 			 * doesn't put an Ethernet header onto the wire, it puts raw
1313 			 * DOCSIS frames out on the wire inside the low-level
1314 			 * Ethernet framing).
1315 			 */
1316 			if (p->dlt_list != NULL) {
1317 				p->dlt_list[dlt_index++] = DLT_EN10MB;
1318 				p->dlt_list[dlt_index++] = DLT_DOCSIS;
1319 			}
1320 			if(!p->linktype)
1321 				p->linktype = DLT_EN10MB;
1322 			break;
1323 
1324 		case ERF_TYPE_ATM:
1325 		case ERF_TYPE_AAL5:
1326 		case ERF_TYPE_MC_ATM:
1327 		case ERF_TYPE_MC_AAL5:
1328 			if (p->dlt_list != NULL) {
1329 				p->dlt_list[dlt_index++] = DLT_ATM_RFC1483;
1330 				p->dlt_list[dlt_index++] = DLT_SUNATM;
1331 			}
1332 			if(!p->linktype)
1333 				p->linktype = DLT_ATM_RFC1483;
1334 			break;
1335 
1336 		case ERF_TYPE_COLOR_MC_HDLC_POS:
1337 		case ERF_TYPE_MC_HDLC:
1338 			if (p->dlt_list != NULL) {
1339 				p->dlt_list[dlt_index++] = DLT_CHDLC;
1340 				p->dlt_list[dlt_index++] = DLT_PPP_SERIAL;
1341 				p->dlt_list[dlt_index++] = DLT_FRELAY;
1342 				p->dlt_list[dlt_index++] = DLT_MTP2;
1343 				p->dlt_list[dlt_index++] = DLT_MTP2_WITH_PHDR;
1344 				p->dlt_list[dlt_index++] = DLT_LAPD;
1345 			}
1346 			if(!p->linktype)
1347 				p->linktype = DLT_CHDLC;
1348 			break;
1349 
1350 		case ERF_TYPE_IPV4:
1351 			if (p->dlt_list != NULL) {
1352 				p->dlt_list[dlt_index++] = DLT_RAW;
1353 				p->dlt_list[dlt_index++] = DLT_IPV4;
1354 			}
1355 			if(!p->linktype)
1356 				p->linktype = DLT_RAW;
1357 			break;
1358 
1359 		case ERF_TYPE_IPV6:
1360 			if (p->dlt_list != NULL) {
1361 				p->dlt_list[dlt_index++] = DLT_RAW;
1362 				p->dlt_list[dlt_index++] = DLT_IPV6;
1363 			}
1364 			if(!p->linktype)
1365 				p->linktype = DLT_RAW;
1366 			break;
1367 
1368 		case ERF_TYPE_LEGACY:
1369 		case ERF_TYPE_MC_RAW:
1370 		case ERF_TYPE_MC_RAW_CHANNEL:
1371 		case ERF_TYPE_IP_COUNTER:
1372 		case ERF_TYPE_TCP_FLOW_COUNTER:
1373 		case ERF_TYPE_INFINIBAND:
1374 		case ERF_TYPE_RAW_LINK:
1375 		case ERF_TYPE_INFINIBAND_LINK:
1376 		case ERF_TYPE_META:
1377 		default:
1378 			/* Libpcap cannot deal with these types yet */
1379 			/* Add no 'native' DLTs, but still covered by DLT_ERF */
1380 			break;
1381 
1382 		} /* switch */
1383 		index++;
1384 	}
1385 
1386 	p->dlt_list[dlt_index++] = DLT_ERF;
1387 
1388 	p->dlt_count = dlt_index;
1389 
1390 	if(!p->linktype)
1391 		p->linktype = DLT_ERF;
1392 
1393 	return p->linktype;
1394 }
1395 
1396 #ifdef DAG_ONLY
1397 /*
1398  * This libpcap build supports only DAG cards, not regular network
1399  * interfaces.
1400  */
1401 
1402 /*
1403  * There are no regular interfaces, just DAG interfaces.
1404  */
1405 int
1406 pcap_platform_finddevs(pcap_if_list_t *devlistp _U_, char *errbuf)
1407 {
1408 	return (0);
1409 }
1410 
1411 /*
1412  * Attempts to open a regular interface fail.
1413  */
1414 pcap_t *
1415 pcap_create_interface(const char *device, char *errbuf)
1416 {
1417 	pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
1418 	    "This version of libpcap only supports DAG cards");
1419 	return NULL;
1420 }
1421 
1422 /*
1423  * Libpcap version string.
1424  */
1425 const char *
1426 pcap_lib_version(void)
1427 {
1428 	return (PCAP_VERSION_STRING " (DAG-only)");
1429 }
1430 #endif
1431