1/*
2 * pcap-dag.c: Packet capture interface for Endace DAG card.
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  <support@endace.com>
14 *                Koryn Grant      <support@endace.com>
15 *                Stephen Donnelly <support@endace.com>
16 */
17
18#ifndef lint
19static const char rcsid[] _U_ =
20	"@(#) $Header: /tcpdump/master/libpcap/pcap-dag.c,v 1.21.2.7 2007/06/22 06:43:58 guy Exp $ (LBL)";
21#endif
22
23#ifdef HAVE_CONFIG_H
24#include "config.h"
25#endif
26
27#include <sys/param.h>			/* optionally get BSD define */
28
29#include <stdlib.h>
30#include <string.h>
31#include <errno.h>
32
33#include "pcap-int.h"
34
35#include <ctype.h>
36#include <netinet/in.h>
37#include <sys/mman.h>
38#include <sys/socket.h>
39#include <sys/types.h>
40#include <unistd.h>
41
42struct mbuf;		/* Squelch compiler warnings on some platforms for */
43struct rtentry;		/* declarations in <net/if.h> */
44#include <net/if.h>
45
46#include "dagnew.h"
47#include "dagapi.h"
48
49#define ATM_CELL_SIZE		52
50#define ATM_HDR_SIZE		4
51
52/*
53 * A header containing additional MTP information.
54 */
55#define MTP2_SENT_OFFSET		0	/* 1 byte */
56#define MTP2_ANNEX_A_USED_OFFSET	1	/* 1 byte */
57#define MTP2_LINK_NUMBER_OFFSET		2	/* 2 bytes */
58#define MTP2_HDR_LEN			4	/* length of the header */
59
60#define MTP2_ANNEX_A_NOT_USED      0
61#define MTP2_ANNEX_A_USED          1
62#define MTP2_ANNEX_A_USED_UNKNOWN  2
63
64/* SunATM pseudo header */
65struct sunatm_hdr {
66	unsigned char	flags;		/* destination and traffic type */
67	unsigned char	vpi;		/* VPI */
68	unsigned short	vci;		/* VCI */
69};
70
71typedef struct pcap_dag_node {
72	struct pcap_dag_node *next;
73	pcap_t *p;
74	pid_t pid;
75} pcap_dag_node_t;
76
77static pcap_dag_node_t *pcap_dags = NULL;
78static int atexit_handler_installed = 0;
79static const unsigned short endian_test_word = 0x0100;
80
81#define IS_BIGENDIAN() (*((unsigned char *)&endian_test_word))
82
83
84#ifdef DAG_ONLY
85/* This code is required when compiling for a DAG device only. */
86#include "pcap-dag.h"
87
88/* Replace dag function names with pcap equivalent. */
89#define dag_open_live pcap_open_live
90#define dag_platform_finddevs pcap_platform_finddevs
91#endif /* DAG_ONLY */
92
93#define MAX_DAG_PACKET 65536
94
95static unsigned char TempPkt[MAX_DAG_PACKET];
96
97static int dag_setfilter(pcap_t *p, struct bpf_program *fp);
98static int dag_stats(pcap_t *p, struct pcap_stat *ps);
99static int dag_set_datalink(pcap_t *p, int dlt);
100static int dag_get_datalink(pcap_t *p);
101static int dag_setnonblock(pcap_t *p, int nonblock, char *errbuf);
102
103static void
104delete_pcap_dag(pcap_t *p)
105{
106	pcap_dag_node_t *curr = NULL, *prev = NULL;
107
108	for (prev = NULL, curr = pcap_dags; curr != NULL && curr->p != p; prev = curr, curr = curr->next) {
109		/* empty */
110	}
111
112	if (curr != NULL && curr->p == p) {
113		if (prev != NULL) {
114			prev->next = curr->next;
115		} else {
116			pcap_dags = curr->next;
117		}
118	}
119}
120
121/*
122 * Performs a graceful shutdown of the DAG card, frees dynamic memory held
123 * in the pcap_t structure, and closes the file descriptor for the DAG card.
124 */
125
126static void
127dag_platform_close(pcap_t *p)
128{
129
130	if (p != NULL) {
131#ifdef HAVE_DAG_STREAMS_API
132		if(dag_stop_stream(p->fd, p->md.dag_stream) < 0)
133			fprintf(stderr,"dag_stop_stream: %s\n", strerror(errno));
134
135		if(dag_detach_stream(p->fd, p->md.dag_stream) < 0)
136			fprintf(stderr,"dag_detach_stream: %s\n", strerror(errno));
137#else
138		if(dag_stop(p->fd) < 0)
139			fprintf(stderr,"dag_stop: %s\n", strerror(errno));
140#endif /* HAVE_DAG_STREAMS_API */
141		if(dag_close(p->fd) < 0)
142			fprintf(stderr,"dag_close: %s\n", strerror(errno));
143	}
144	delete_pcap_dag(p);
145	/* Note: don't need to call close(p->fd) here as dag_close(p->fd) does this. */
146}
147
148static void
149atexit_handler(void)
150{
151	while (pcap_dags != NULL) {
152		if (pcap_dags->pid == getpid()) {
153			dag_platform_close(pcap_dags->p);
154		} else {
155			delete_pcap_dag(pcap_dags->p);
156		}
157	}
158}
159
160static int
161new_pcap_dag(pcap_t *p)
162{
163	pcap_dag_node_t *node = NULL;
164
165	if ((node = malloc(sizeof(pcap_dag_node_t))) == NULL) {
166		return -1;
167	}
168
169	if (!atexit_handler_installed) {
170		atexit(atexit_handler);
171		atexit_handler_installed = 1;
172	}
173
174	node->next = pcap_dags;
175	node->p = p;
176	node->pid = getpid();
177
178	pcap_dags = node;
179
180	return 0;
181}
182
183/*
184 *  Read at most max_packets from the capture stream and call the callback
185 *  for each of them. Returns the number of packets handled, -1 if an
186 *  error occured, or -2 if we were told to break out of the loop.
187 */
188static int
189dag_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
190{
191	unsigned int processed = 0;
192	int flags = p->md.dag_offset_flags;
193	unsigned int nonblocking = flags & DAGF_NONBLOCK;
194
195	/* Get the next bufferful of packets (if necessary). */
196	while (p->md.dag_mem_top - p->md.dag_mem_bottom < dag_record_size) {
197
198		/*
199		 * Has "pcap_breakloop()" been called?
200		 */
201		if (p->break_loop) {
202			/*
203			 * Yes - clear the flag that indicates that
204			 * it has, and return -2 to indicate that
205			 * we were told to break out of the loop.
206			 */
207			p->break_loop = 0;
208			return -2;
209		}
210
211#ifdef HAVE_DAG_STREAMS_API
212		/* dag_advance_stream() will block (unless nonblock is called)
213		 * until 64kB of data has accumulated.
214		 * If to_ms is set, it will timeout before 64kB has accumulated.
215		 * We wait for 64kB because processing a few packets at a time
216		 * can cause problems at high packet rates (>200kpps) due
217		 * to inefficiencies.
218		 * This does mean if to_ms is not specified the capture may 'hang'
219		 * for long periods if the data rate is extremely slow (<64kB/sec)
220		 * If non-block is specified it will return immediately. The user
221		 * is then responsible for efficiency.
222		 */
223		p->md.dag_mem_top = dag_advance_stream(p->fd, p->md.dag_stream, &(p->md.dag_mem_bottom));
224#else
225		/* dag_offset does not support timeouts */
226		p->md.dag_mem_top = dag_offset(p->fd, &(p->md.dag_mem_bottom), flags);
227#endif /* HAVE_DAG_STREAMS_API */
228
229		if (nonblocking && (p->md.dag_mem_top - p->md.dag_mem_bottom < dag_record_size))
230		{
231			/* Pcap is configured to process only available packets, and there aren't any, return immediately. */
232			return 0;
233		}
234
235		if(!nonblocking &&
236		   p->md.dag_timeout &&
237		   (p->md.dag_mem_top - p->md.dag_mem_bottom < dag_record_size))
238		{
239			/* Blocking mode, but timeout set and no data has arrived, return anyway.*/
240			return 0;
241		}
242
243	}
244
245	/* Process the packets. */
246	while (p->md.dag_mem_top - p->md.dag_mem_bottom >= dag_record_size) {
247
248		unsigned short packet_len = 0;
249		int caplen = 0;
250		struct pcap_pkthdr	pcap_header;
251
252#ifdef HAVE_DAG_STREAMS_API
253		dag_record_t *header = (dag_record_t *)(p->md.dag_mem_bottom);
254#else
255		dag_record_t *header = (dag_record_t *)(p->md.dag_mem_base + p->md.dag_mem_bottom);
256#endif /* HAVE_DAG_STREAMS_API */
257
258		u_char *dp = ((u_char *)header) + dag_record_size;
259		unsigned short rlen;
260
261		/*
262		 * Has "pcap_breakloop()" been called?
263		 */
264		if (p->break_loop) {
265			/*
266			 * Yes - clear the flag that indicates that
267			 * it has, and return -2 to indicate that
268			 * we were told to break out of the loop.
269			 */
270			p->break_loop = 0;
271			return -2;
272		}
273
274		rlen = ntohs(header->rlen);
275		if (rlen < dag_record_size)
276		{
277			strncpy(p->errbuf, "dag_read: record too small", PCAP_ERRBUF_SIZE);
278			return -1;
279		}
280		p->md.dag_mem_bottom += rlen;
281
282		switch(header->type) {
283		case TYPE_ATM:
284#ifdef TYPE_AAL5
285		case TYPE_AAL5:
286			if (header->type == TYPE_AAL5) {
287				packet_len = ntohs(header->wlen);
288				caplen = rlen - dag_record_size;
289			}
290#endif
291#ifdef TYPE_MC_ATM
292		case TYPE_MC_ATM:
293			if (header->type == TYPE_MC_ATM) {
294				caplen = packet_len = ATM_CELL_SIZE;
295				dp+=4;
296			}
297#endif
298#ifdef TYPE_MC_AAL5
299		case TYPE_MC_AAL5:
300			if (header->type == TYPE_MC_AAL5) {
301				packet_len = ntohs(header->wlen);
302				caplen = rlen - dag_record_size - 4;
303				dp+=4;
304			}
305#endif
306			if (header->type == TYPE_ATM) {
307				caplen = packet_len = ATM_CELL_SIZE;
308			}
309			if (p->linktype == DLT_SUNATM) {
310				struct sunatm_hdr *sunatm = (struct sunatm_hdr *)dp;
311				unsigned long rawatm;
312
313				rawatm = ntohl(*((unsigned long *)dp));
314				sunatm->vci = htons((rawatm >>  4) & 0xffff);
315				sunatm->vpi = (rawatm >> 20) & 0x00ff;
316				sunatm->flags = ((header->flags.iface & 1) ? 0x80 : 0x00) |
317					((sunatm->vpi == 0 && sunatm->vci == htons(5)) ? 6 :
318					 ((sunatm->vpi == 0 && sunatm->vci == htons(16)) ? 5 :
319					  ((dp[ATM_HDR_SIZE] == 0xaa &&
320					    dp[ATM_HDR_SIZE+1] == 0xaa &&
321					    dp[ATM_HDR_SIZE+2] == 0x03) ? 2 : 1)));
322
323			} else {
324				packet_len -= ATM_HDR_SIZE;
325				caplen -= ATM_HDR_SIZE;
326				dp += ATM_HDR_SIZE;
327			}
328			break;
329
330#ifdef TYPE_DSM_COLOR_ETH
331		case TYPE_DSM_COLOR_ETH:
332#endif
333#ifdef TYPE_COLOR_ETH
334		case TYPE_COLOR_ETH:
335#endif
336		case TYPE_ETH:
337			packet_len = ntohs(header->wlen);
338			packet_len -= (p->md.dag_fcs_bits >> 3);
339			caplen = rlen - dag_record_size - 2;
340			if (caplen > packet_len) {
341				caplen = packet_len;
342			}
343			dp += 2;
344			break;
345#ifdef TYPE_DSM_COLOR_HDLC_POS
346		case TYPE_DSM_COLOR_HDLC_POS:
347#endif
348#ifdef TYPE_COLOR_HDLC_POS
349		case TYPE_COLOR_HDLC_POS:
350#endif
351		case TYPE_HDLC_POS:
352			packet_len = ntohs(header->wlen);
353			packet_len -= (p->md.dag_fcs_bits >> 3);
354			caplen = rlen - dag_record_size;
355			if (caplen > packet_len) {
356				caplen = packet_len;
357			}
358			break;
359#ifdef TYPE_COLOR_MC_HDLC_POS
360		case TYPE_COLOR_MC_HDLC_POS:
361#endif
362#ifdef TYPE_MC_HDLC
363		case TYPE_MC_HDLC:
364			packet_len = ntohs(header->wlen);
365			packet_len -= (p->md.dag_fcs_bits >> 3);
366			caplen = rlen - dag_record_size - 4;
367			if (caplen > packet_len) {
368				caplen = packet_len;
369			}
370			/* jump the MC_HDLC_HEADER */
371			dp += 4;
372			if (p->linktype == DLT_MTP2_WITH_PHDR) {
373				/* Add the MTP2 Pseudo Header */
374				caplen += MTP2_HDR_LEN;
375				packet_len += MTP2_HDR_LEN;
376
377				TempPkt[MTP2_SENT_OFFSET] = 0;
378				TempPkt[MTP2_ANNEX_A_USED_OFFSET] = MTP2_ANNEX_A_USED_UNKNOWN;
379				*(TempPkt+MTP2_LINK_NUMBER_OFFSET) = ((header->rec.mc_hdlc.mc_header>>16)&0x01);
380				*(TempPkt+MTP2_LINK_NUMBER_OFFSET+1) = ((header->rec.mc_hdlc.mc_header>>24)&0xff);
381				memcpy(TempPkt+MTP2_HDR_LEN, dp, caplen);
382				dp = TempPkt;
383			}
384			break;
385#endif
386		default:
387			/* Unhandled ERF type.
388			 * Ignore rather than generating error
389			 */
390			continue;
391		}
392
393		if (caplen > p->snapshot)
394			caplen = p->snapshot;
395
396		/* Count lost packets. */
397		switch(header->type) {
398#ifdef TYPE_COLOR_HDLC_POS
399			/* in this type the color value overwrites the lctr */
400		case TYPE_COLOR_HDLC_POS:
401			break;
402#endif
403#ifdef TYPE_COLOR_ETH
404			/* in this type the color value overwrites the lctr */
405		case TYPE_COLOR_ETH:
406			break;
407#endif
408#ifdef TYPE_DSM_COLOR_HDLC_POS
409			/* in this type the color value overwrites the lctr */
410		case TYPE_DSM_COLOR_HDLC_POS:
411			break;
412#endif
413#ifdef TYPE_DSM_COLOR_ETH
414			/* in this type the color value overwrites the lctr */
415		case TYPE_DSM_COLOR_ETH:
416			break;
417#endif
418#ifdef TYPE_COLOR_MC_HDLC_POS
419		case TYPE_COLOR_MC_HDLC_POS:
420			break;
421#endif
422
423		default:
424			if (header->lctr) {
425				if (p->md.stat.ps_drop > (UINT_MAX - ntohs(header->lctr))) {
426					p->md.stat.ps_drop = UINT_MAX;
427				} else {
428					p->md.stat.ps_drop += ntohs(header->lctr);
429				}
430			}
431		}
432
433		/* Run the packet filter if there is one. */
434		if ((p->fcode.bf_insns == NULL) || bpf_filter(p->fcode.bf_insns, dp, packet_len, caplen)) {
435
436			/* convert between timestamp formats */
437			register unsigned long long ts;
438
439			if (IS_BIGENDIAN()) {
440				ts = SWAPLL(header->ts);
441			} else {
442				ts = header->ts;
443			}
444
445			pcap_header.ts.tv_sec = ts >> 32;
446			ts = (ts & 0xffffffffULL) * 1000000;
447			ts += 0x80000000; /* rounding */
448			pcap_header.ts.tv_usec = ts >> 32;
449			if (pcap_header.ts.tv_usec >= 1000000) {
450				pcap_header.ts.tv_usec -= 1000000;
451				pcap_header.ts.tv_sec++;
452			}
453
454			/* Fill in our own header data */
455			pcap_header.caplen = caplen;
456			pcap_header.len = packet_len;
457
458			/* Count the packet. */
459			p->md.stat.ps_recv++;
460
461			/* Call the user supplied callback function */
462			callback(user, &pcap_header, dp);
463
464			/* Only count packets that pass the filter, for consistency with standard Linux behaviour. */
465			processed++;
466			if (processed == cnt)
467			{
468				/* Reached the user-specified limit. */
469				return cnt;
470			}
471		}
472	}
473
474	return processed;
475}
476
477static int
478dag_inject(pcap_t *p, const void *buf _U_, size_t size _U_)
479{
480	strlcpy(p->errbuf, "Sending packets isn't supported on DAG cards",
481	    PCAP_ERRBUF_SIZE);
482	return (-1);
483}
484
485/*
486 *  Get a handle for a live capture from the given DAG device.  Passing a NULL
487 *  device will result in a failure.  The promisc flag is ignored because DAG
488 *  cards are always promiscuous.  The to_ms parameter is also ignored as it is
489 *  not supported in hardware.
490 *
491 *  snaplen is now also ignored, until we get per-stream slen support. Set
492 *  slen with approprite DAG tool BEFORE pcap_open_live().
493 *
494 *  See also pcap(3).
495 */
496pcap_t *
497dag_open_live(const char *device, int snaplen, int promisc, int to_ms, char *ebuf)
498{
499	char conf[30]; /* dag configure string */
500	pcap_t *handle;
501	char *s;
502	int n;
503	daginf_t* daginf;
504	char * newDev = NULL;
505#ifdef HAVE_DAG_STREAMS_API
506	uint32_t mindata;
507	struct timeval maxwait;
508	struct timeval poll;
509#endif
510
511	if (device == NULL) {
512		snprintf(ebuf, PCAP_ERRBUF_SIZE, "device is NULL: %s", pcap_strerror(errno));
513		return NULL;
514	}
515	/* Allocate a handle for this session. */
516
517	handle = malloc(sizeof(*handle));
518	if (handle == NULL) {
519		snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc %s: %s", device, pcap_strerror(errno));
520		return NULL;
521	}
522
523	/* Initialize some components of the pcap structure. */
524
525	memset(handle, 0, sizeof(*handle));
526
527#ifdef HAVE_DAG_STREAMS_API
528	newDev = (char *)malloc(strlen(device) + 16);
529	if (newDev == NULL) {
530		snprintf(ebuf, PCAP_ERRBUF_SIZE, "Can't allocate string for device name: %s\n", pcap_strerror(errno));
531		goto fail;
532	}
533
534	/* Parse input name to get dag device and stream number if provided */
535	if (dag_parse_name(device, newDev, strlen(device) + 16, &handle->md.dag_stream) < 0) {
536		snprintf(ebuf, PCAP_ERRBUF_SIZE, "dag_parse_name: %s\n", pcap_strerror(errno));
537		goto fail;
538	}
539	device = newDev;
540
541	if (handle->md.dag_stream%2) {
542		snprintf(ebuf, PCAP_ERRBUF_SIZE, "dag_parse_name: tx (even numbered) streams not supported for capture\n");
543		goto fail;
544	}
545#else
546	if (strncmp(device, "/dev/", 5) != 0) {
547		newDev = (char *)malloc(strlen(device) + 5);
548		if (newDev == NULL) {
549			snprintf(ebuf, PCAP_ERRBUF_SIZE, "Can't allocate string for device name: %s\n", pcap_strerror(errno));
550			goto fail;
551		}
552		strcpy(newDev, "/dev/");
553		strcat(newDev, device);
554		device = newDev;
555	}
556#endif /* HAVE_DAG_STREAMS_API */
557
558	/* setup device parameters */
559	if((handle->fd = dag_open((char *)device)) < 0) {
560		snprintf(ebuf, PCAP_ERRBUF_SIZE, "dag_open %s: %s", device, pcap_strerror(errno));
561		goto fail;
562	}
563
564#ifdef HAVE_DAG_STREAMS_API
565	/* Open requested stream. Can fail if already locked or on error */
566	if (dag_attach_stream(handle->fd, handle->md.dag_stream, 0, 0) < 0) {
567		snprintf(ebuf, PCAP_ERRBUF_SIZE, "dag_attach_stream: %s\n", pcap_strerror(errno));
568		goto failclose;
569	}
570
571	/* Set up default poll parameters for stream
572	 * Can be overridden by pcap_set_nonblock()
573	 */
574	if (dag_get_stream_poll(handle->fd, handle->md.dag_stream,
575				&mindata, &maxwait, &poll) < 0) {
576		snprintf(ebuf, PCAP_ERRBUF_SIZE, "dag_get_stream_poll: %s\n", pcap_strerror(errno));
577		goto faildetach;
578	}
579
580	/* Amount of data to collect in Bytes before calling callbacks.
581	 * Important for efficiency, but can introduce latency
582	 * at low packet rates if to_ms not set!
583	 */
584	mindata = 65536;
585
586	/* Obey to_ms if supplied. This is a good idea!
587	 * Recommend 10-100ms. Calls will time out even if no data arrived.
588	 */
589	maxwait.tv_sec = to_ms/1000;
590	maxwait.tv_usec = (to_ms%1000) * 1000;
591
592	if (dag_set_stream_poll(handle->fd, handle->md.dag_stream,
593				mindata, &maxwait, &poll) < 0) {
594		snprintf(ebuf, PCAP_ERRBUF_SIZE, "dag_set_stream_poll: %s\n", pcap_strerror(errno));
595		goto faildetach;
596	}
597
598#else
599	if((handle->md.dag_mem_base = dag_mmap(handle->fd)) == MAP_FAILED) {
600		snprintf(ebuf, PCAP_ERRBUF_SIZE,"dag_mmap %s: %s\n", device, pcap_strerror(errno));
601		goto failclose;
602	}
603
604#endif /* HAVE_DAG_STREAMS_API */
605
606        /* XXX Not calling dag_configure() to set slen; this is unsafe in
607	 * multi-stream environments as the gpp config is global.
608         * Once the firmware provides 'per-stream slen' this can be supported
609	 * again via the Config API without side-effects */
610#if 0
611	/* set the card snap length to the specified snaplen parameter */
612	/* This is a really bad idea, as different cards have different
613	 * valid slen ranges. Should fix in Config API. */
614	if (snaplen == 0 || snaplen > MAX_DAG_SNAPLEN) {
615		snaplen = MAX_DAG_SNAPLEN;
616	} else if (snaplen < MIN_DAG_SNAPLEN) {
617		snaplen = MIN_DAG_SNAPLEN;
618	}
619	/* snap len has to be a multiple of 4 */
620	snprintf(conf, 30, "varlen slen=%d", (snaplen + 3) & ~3);
621
622	if(dag_configure(handle->fd, conf) < 0) {
623		snprintf(ebuf, PCAP_ERRBUF_SIZE,"dag_configure %s: %s\n", device, pcap_strerror(errno));
624		goto faildetach;
625	}
626#endif
627
628#ifdef HAVE_DAG_STREAMS_API
629	if(dag_start_stream(handle->fd, handle->md.dag_stream) < 0) {
630		snprintf(ebuf, PCAP_ERRBUF_SIZE, "dag_start_stream %s: %s\n", device, pcap_strerror(errno));
631		goto faildetach;
632	}
633#else
634	if(dag_start(handle->fd) < 0) {
635		snprintf(ebuf, PCAP_ERRBUF_SIZE, "dag_start %s: %s\n", device, pcap_strerror(errno));
636		goto failclose;
637	}
638#endif /* HAVE_DAG_STREAMS_API */
639
640	/*
641	 * Important! You have to ensure bottom is properly
642	 * initialized to zero on startup, it won't give you
643	 * a compiler warning if you make this mistake!
644	 */
645	handle->md.dag_mem_bottom = 0;
646	handle->md.dag_mem_top = 0;
647	handle->md.dag_fcs_bits = 32;
648
649	/* Query the card first for special cases. */
650	daginf = dag_info(handle->fd);
651	if ((0x4200 == daginf->device_code) || (0x4230 == daginf->device_code))
652	{
653		/* DAG 4.2S and 4.23S already strip the FCS.  Stripping the final word again truncates the packet. */
654		handle->md.dag_fcs_bits = 0;
655	}
656
657	/* Then allow an environment variable to override. */
658	if ((s = getenv("ERF_FCS_BITS")) != NULL) {
659		if ((n = atoi(s)) == 0 || n == 16|| n == 32) {
660			handle->md.dag_fcs_bits = n;
661		} else {
662			snprintf(ebuf, PCAP_ERRBUF_SIZE,
663				"pcap_open_live %s: bad ERF_FCS_BITS value (%d) in environment\n", device, n);
664			goto failstop;
665		}
666	}
667
668	handle->snapshot	= snaplen;
669	handle->md.dag_timeout	= to_ms;
670
671	handle->linktype = -1;
672	if (dag_get_datalink(handle) < 0) {
673		strcpy(ebuf, handle->errbuf);
674		goto failstop;
675	}
676
677	handle->bufsize = 0;
678
679	if (new_pcap_dag(handle) < 0) {
680		snprintf(ebuf, PCAP_ERRBUF_SIZE, "new_pcap_dag %s: %s\n", device, pcap_strerror(errno));
681		goto failstop;
682	}
683
684	/*
685	 * "select()" and "poll()" don't work on DAG device descriptors.
686	 */
687	handle->selectable_fd = -1;
688
689	if (newDev != NULL) {
690		free((char *)newDev);
691	}
692
693	handle->read_op = dag_read;
694	handle->inject_op = dag_inject;
695	handle->setfilter_op = dag_setfilter;
696	handle->setdirection_op = NULL; /* Not implemented.*/
697	handle->set_datalink_op = dag_set_datalink;
698	handle->getnonblock_op = pcap_getnonblock_fd;
699	handle->setnonblock_op = dag_setnonblock;
700	handle->stats_op = dag_stats;
701	handle->close_op = dag_platform_close;
702	handle->md.stat.ps_drop = 0;
703	handle->md.stat.ps_recv = 0;
704	return handle;
705
706#ifdef HAVE_DAG_STREAMS_API
707failstop:
708	if (handle != NULL) {
709		if (dag_stop_stream(handle->fd, handle->md.dag_stream) < 0)
710			fprintf(stderr,"dag_stop_stream: %s\n", strerror(errno));
711	}
712
713faildetach:
714	if (handle != NULL) {
715		if (dag_detach_stream(handle->fd, handle->md.dag_stream) < 0)
716			fprintf(stderr,"dag_detach_stream: %s\n", strerror(errno));
717	}
718#else
719failstop:
720	if (handle != NULL) {
721		if (dag_stop(p->fd) < 0)
722			fprintf(stderr,"dag_stop: %s\n", strerror(errno));
723	}
724#endif /* HAVE_DAG_STREAMS_API */
725
726failclose:
727	if (handle != NULL) {
728		if (dag_close(handle->fd) < 0)
729			fprintf(stderr,"dag_close: %s\n", strerror(errno));
730	}
731	if (handle != NULL)
732		delete_pcap_dag(handle);
733
734fail:
735	if (newDev != NULL) {
736		free((char *)newDev);
737	}
738	if (handle != NULL) {
739		/*
740		 * Get rid of any link-layer type list we allocated.
741		 */
742		if (handle->dlt_list != NULL) {
743			free(handle->dlt_list);
744		}
745		free(handle);
746	}
747
748	return NULL;
749}
750
751static int
752dag_stats(pcap_t *p, struct pcap_stat *ps) {
753	/* This needs to be filled out correctly.  Hopefully a dagapi call will
754		 provide all necessary information.
755	*/
756	/*p->md.stat.ps_recv = 0;*/
757	/*p->md.stat.ps_drop = 0;*/
758
759	*ps = p->md.stat;
760
761	return 0;
762}
763
764/*
765 * Simply submit all possible dag names as candidates.
766 * pcap_add_if() internally tests each candidate with pcap_open_live(),
767 * so any non-existent devices are dropped.
768 * For 2.5 try all rx stream names as well.
769 */
770int
771dag_platform_finddevs(pcap_if_t **devlistp, char *errbuf)
772{
773	char name[12];	/* XXX - pick a size */
774	int ret = 0;
775	int c;
776
777	/* Try all the DAGs 0-9 */
778	for (c = 0; c < 9; c++) {
779		snprintf(name, 12, "dag%d", c);
780		if (pcap_add_if(devlistp, name, 0, NULL, errbuf) == -1) {
781			/*
782			 * Failure.
783			 */
784			ret = -1;
785		}
786#ifdef HAVE_DAG_STREAMS_API
787		{
788			int stream;
789			for(stream=0;stream<16;stream+=2) {
790				snprintf(name,  10, "dag%d:%d", c, stream);
791				if (pcap_add_if(devlistp, name, 0, NULL, errbuf) == -1) {
792					/*
793					 * Failure.
794					 */
795					ret = -1;
796				}
797			}
798		}
799#endif  /* HAVE_DAG_STREAMS_API */
800	}
801	return (ret);
802}
803
804/*
805 * Installs the given bpf filter program in the given pcap structure.  There is
806 * no attempt to store the filter in kernel memory as that is not supported
807 * with DAG cards.
808 */
809static int
810dag_setfilter(pcap_t *p, struct bpf_program *fp)
811{
812	if (!p)
813		return -1;
814	if (!fp) {
815		strncpy(p->errbuf, "setfilter: No filter specified",
816			sizeof(p->errbuf));
817		return -1;
818	}
819
820	/* Make our private copy of the filter */
821
822	if (install_bpf_program(p, fp) < 0)
823		return -1;
824
825	p->md.use_bpf = 0;
826
827	return (0);
828}
829
830static int
831dag_set_datalink(pcap_t *p, int dlt)
832{
833	p->linktype = dlt;
834
835	return (0);
836}
837
838static int
839dag_setnonblock(pcap_t *p, int nonblock, char *errbuf)
840{
841	/*
842	 * Set non-blocking mode on the FD.
843	 * XXX - is that necessary?  If not, don't bother calling it,
844	 * and have a "dag_getnonblock()" function that looks at
845	 * "p->md.dag_offset_flags".
846	 */
847	if (pcap_setnonblock_fd(p, nonblock, errbuf) < 0)
848		return (-1);
849#ifdef HAVE_DAG_STREAMS_API
850	{
851		uint32_t mindata;
852		struct timeval maxwait;
853		struct timeval poll;
854
855		if (dag_get_stream_poll(p->fd, p->md.dag_stream,
856					&mindata, &maxwait, &poll) < 0) {
857			snprintf(errbuf, PCAP_ERRBUF_SIZE, "dag_get_stream_poll: %s\n", pcap_strerror(errno));
858			return -1;
859		}
860
861		/* Amount of data to collect in Bytes before calling callbacks.
862		 * Important for efficiency, but can introduce latency
863		 * at low packet rates if to_ms not set!
864		 */
865		if(nonblock)
866			mindata = 0;
867		else
868			mindata = 65536;
869
870		if (dag_set_stream_poll(p->fd, p->md.dag_stream,
871					mindata, &maxwait, &poll) < 0) {
872			snprintf(errbuf, PCAP_ERRBUF_SIZE, "dag_set_stream_poll: %s\n", pcap_strerror(errno));
873			return -1;
874		}
875	}
876#endif /* HAVE_DAG_STREAMS_API */
877	if (nonblock) {
878		p->md.dag_offset_flags |= DAGF_NONBLOCK;
879	} else {
880		p->md.dag_offset_flags &= ~DAGF_NONBLOCK;
881	}
882	return (0);
883}
884
885static int
886dag_get_datalink(pcap_t *p)
887{
888	int index=0;
889	uint8_t types[255];
890
891	memset(types, 0, 255);
892
893	if (p->dlt_list == NULL && (p->dlt_list = malloc(255*sizeof(*(p->dlt_list)))) == NULL) {
894		(void)snprintf(p->errbuf, sizeof(p->errbuf), "malloc: %s", pcap_strerror(errno));
895		return (-1);
896	}
897
898	p->linktype = 0;
899
900#ifdef HAVE_DAG_GET_ERF_TYPES
901	/* Get list of possible ERF types for this card */
902	if (dag_get_erf_types(p->fd, types, 255) < 0) {
903		snprintf(p->errbuf, sizeof(p->errbuf), "dag_get_erf_types: %s", pcap_strerror(errno));
904		return (-1);
905	}
906
907	while (types[index]) {
908#else
909	/* Check the type through a dagapi call. */
910	types[index] = dag_linktype(p->fd);
911
912	{
913#endif
914		switch(types[index]) {
915
916		case TYPE_HDLC_POS:
917#ifdef TYPE_COLOR_HDLC_POS
918		case TYPE_COLOR_HDLC_POS:
919#endif
920#ifdef TYPE_DSM_COLOR_HDLC_POS
921		case TYPE_DSM_COLOR_HDLC_POS:
922#endif
923			if (p->dlt_list != NULL) {
924				p->dlt_list[index++] = DLT_CHDLC;
925				p->dlt_list[index++] = DLT_PPP_SERIAL;
926				p->dlt_list[index++] = DLT_FRELAY;
927			}
928			if(!p->linktype)
929				p->linktype = DLT_CHDLC;
930			break;
931
932		case TYPE_ETH:
933#ifdef TYPE_COLOR_ETH
934		case TYPE_COLOR_ETH:
935#endif
936#ifdef TYPE_DSM_COLOR_ETH
937		case TYPE_DSM_COLOR_ETH:
938#endif
939			/*
940			 * This is (presumably) a real Ethernet capture; give it a
941			 * link-layer-type list with DLT_EN10MB and DLT_DOCSIS, so
942			 * that an application can let you choose it, in case you're
943			 * capturing DOCSIS traffic that a Cisco Cable Modem
944			 * Termination System is putting out onto an Ethernet (it
945			 * doesn't put an Ethernet header onto the wire, it puts raw
946			 * DOCSIS frames out on the wire inside the low-level
947			 * Ethernet framing).
948			 */
949			if (p->dlt_list != NULL) {
950				p->dlt_list[index++] = DLT_EN10MB;
951				p->dlt_list[index++] = DLT_DOCSIS;
952			}
953			if(!p->linktype)
954				p->linktype = DLT_EN10MB;
955			break;
956
957		case TYPE_ATM:
958#ifdef TYPE_AAL5
959		case TYPE_AAL5:
960#endif
961#ifdef TYPE_MC_ATM
962		case TYPE_MC_ATM:
963#endif
964#ifdef TYPE_MC_AAL5
965		case TYPE_MC_AAL5:
966#endif
967			if (p->dlt_list != NULL) {
968				p->dlt_list[index++] = DLT_ATM_RFC1483;
969				p->dlt_list[index++] = DLT_SUNATM;
970			}
971			if(!p->linktype)
972				p->linktype = DLT_ATM_RFC1483;
973			break;
974
975#ifdef TYPE_COLOR_MC_HDLC_POS
976		case TYPE_COLOR_MC_HDLC_POS:
977#endif
978#ifdef TYPE_MC_HDLC
979		case TYPE_MC_HDLC:
980			if (p->dlt_list != NULL) {
981				p->dlt_list[index++] = DLT_CHDLC;
982				p->dlt_list[index++] = DLT_PPP_SERIAL;
983				p->dlt_list[index++] = DLT_FRELAY;
984				p->dlt_list[index++] = DLT_MTP2;
985				p->dlt_list[index++] = DLT_MTP2_WITH_PHDR;
986			}
987			if(!p->linktype)
988				p->linktype = DLT_CHDLC;
989			break;
990#endif
991
992		case TYPE_LEGACY:
993			if(!p->linktype)
994				p->linktype = DLT_NULL;
995			break;
996
997		default:
998			snprintf(p->errbuf, sizeof(p->errbuf), "unknown DAG linktype %d", types[index]);
999			return (-1);
1000
1001		} /* switch */
1002	}
1003
1004	p->dlt_count = index;
1005
1006	return p->linktype;
1007}
1008