• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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
19 static 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 
42 struct mbuf;		/* Squelch compiler warnings on some platforms for */
43 struct 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 */
65 struct sunatm_hdr {
66 	unsigned char	flags;		/* destination and traffic type */
67 	unsigned char	vpi;		/* VPI */
68 	unsigned short	vci;		/* VCI */
69 };
70 
71 typedef struct pcap_dag_node {
72 	struct pcap_dag_node *next;
73 	pcap_t *p;
74 	pid_t pid;
75 } pcap_dag_node_t;
76 
77 static pcap_dag_node_t *pcap_dags = NULL;
78 static int atexit_handler_installed = 0;
79 static 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 
95 static unsigned char TempPkt[MAX_DAG_PACKET];
96 
97 static int dag_setfilter(pcap_t *p, struct bpf_program *fp);
98 static int dag_stats(pcap_t *p, struct pcap_stat *ps);
99 static int dag_set_datalink(pcap_t *p, int dlt);
100 static int dag_get_datalink(pcap_t *p);
101 static int dag_setnonblock(pcap_t *p, int nonblock, char *errbuf);
102 
103 static void
delete_pcap_dag(pcap_t * p)104 delete_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 
126 static void
dag_platform_close(pcap_t * p)127 dag_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 
148 static void
atexit_handler(void)149 atexit_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 
160 static int
new_pcap_dag(pcap_t * p)161 new_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  */
188 static int
dag_read(pcap_t * p,int cnt,pcap_handler callback,u_char * user)189 dag_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 
477 static int
dag_inject(pcap_t * p,const void * buf _U_,size_t size _U_)478 dag_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  */
496 pcap_t *
dag_open_live(const char * device,int snaplen,int promisc,int to_ms,char * ebuf)497 dag_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
707 failstop:
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 
713 faildetach:
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
719 failstop:
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 
726 failclose:
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 
734 fail:
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 
751 static int
dag_stats(pcap_t * p,struct pcap_stat * ps)752 dag_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  */
770 int
dag_platform_finddevs(pcap_if_t ** devlistp,char * errbuf)771 dag_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  */
809 static int
dag_setfilter(pcap_t * p,struct bpf_program * fp)810 dag_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 
830 static int
dag_set_datalink(pcap_t * p,int dlt)831 dag_set_datalink(pcap_t *p, int dlt)
832 {
833 	p->linktype = dlt;
834 
835 	return (0);
836 }
837 
838 static int
dag_setnonblock(pcap_t * p,int nonblock,char * errbuf)839 dag_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 
885 static int
dag_get_datalink(pcap_t * p)886 dag_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