2 * pcap-dag.c: Packet capture interface for Endace DAG card.
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.
12 * Authors: Richard Littin, Sean Irvine ({richard,sean}@reeltwo.com)
13 * Modifications: Jesper Peterson, Koryn Grant <support@endace.com>
17 static const char rcsid[] _U_ =
18 "@(#) $Header: /tcpdump/master/libpcap/pcap-dag.c,v 1.21 2005/04/03 23:56:47 guy Exp $ (LBL)";
25 #include <sys/param.h> /* optionally get BSD define */
34 #include <netinet/in.h>
36 #include <sys/socket.h>
37 #include <sys/types.h>
40 struct mbuf; /* Squelch compiler warnings on some platforms for */
41 struct rtentry; /* declarations in <net/if.h> */
47 #define MIN_DAG_SNAPLEN 12
48 #define MAX_DAG_SNAPLEN 2040
49 #define ATM_CELL_SIZE 52
50 #define ATM_HDR_SIZE 4
52 /* SunATM pseudo header */
54 unsigned char flags; /* destination and traffic type */
55 unsigned char vpi; /* VPI */
56 unsigned short vci; /* VCI */
59 typedef struct pcap_dag_node {
60 struct pcap_dag_node *next;
65 static pcap_dag_node_t *pcap_dags = NULL;
66 static int atexit_handler_installed = 0;
67 static const unsigned short endian_test_word = 0x0100;
69 #define IS_BIGENDIAN() (*((unsigned char *)&endian_test_word))
72 * Swap byte ordering of unsigned long long timestamp on a big endian
75 #define SWAP_TS(ull) ((ull & 0xff00000000000000LL) >> 56) | \
76 ((ull & 0x00ff000000000000LL) >> 40) | \
77 ((ull & 0x0000ff0000000000LL) >> 24) | \
78 ((ull & 0x000000ff00000000LL) >> 8) | \
79 ((ull & 0x00000000ff000000LL) << 8) | \
80 ((ull & 0x0000000000ff0000LL) << 24) | \
81 ((ull & 0x000000000000ff00LL) << 40) | \
82 ((ull & 0x00000000000000ffLL) << 56)
86 /* This code is required when compiling for a DAG device only. */
89 /* Replace dag function names with pcap equivalent. */
90 #define dag_open_live pcap_open_live
91 #define dag_platform_finddevs pcap_platform_finddevs
94 static int dag_setfilter(pcap_t *p, struct bpf_program *fp);
95 static int dag_stats(pcap_t *p, struct pcap_stat *ps);
96 static int dag_set_datalink(pcap_t *p, int dlt);
97 static int dag_get_datalink(pcap_t *p);
98 static int dag_setnonblock(pcap_t *p, int nonblock, char *errbuf);
101 delete_pcap_dag(pcap_t *p)
103 pcap_dag_node_t *curr = NULL, *prev = NULL;
105 for (prev = NULL, curr = pcap_dags; curr != NULL && curr->p != p; prev = curr, curr = curr->next) {
109 if (curr != NULL && curr->p == p) {
111 prev->next = curr->next;
113 pcap_dags = curr->next;
119 * Performs a graceful shutdown of the DAG card, frees dynamic memory held
120 * in the pcap_t structure, and closes the file descriptor for the DAG card.
124 dag_platform_close(pcap_t *p)
128 if (p != NULL && p->md.device != NULL) {
129 if(dag_stop(p->fd) < 0)
130 fprintf(stderr,"dag_stop %s: %s\n", p->md.device, strerror(errno));
131 if(dag_close(p->fd) < 0)
132 fprintf(stderr,"dag_close %s: %s\n", p->md.device, strerror(errno));
138 if(dag_stop(p->fd) < 0)
139 fprintf(stderr,"dag_stop: %s\n", strerror(errno));
140 if(dag_close(p->fd) < 0)
141 fprintf(stderr,"dag_close: %s\n", strerror(errno));
145 /* Note: don't need to call close(p->fd) here as dag_close(p->fd) does this. */
151 while (pcap_dags != NULL) {
152 if (pcap_dags->pid == getpid()) {
153 dag_platform_close(pcap_dags->p);
155 delete_pcap_dag(pcap_dags->p);
161 new_pcap_dag(pcap_t *p)
163 pcap_dag_node_t *node = NULL;
165 if ((node = malloc(sizeof(pcap_dag_node_t))) == NULL) {
169 if (!atexit_handler_installed) {
170 atexit(atexit_handler);
171 atexit_handler_installed = 1;
174 node->next = pcap_dags;
176 node->pid = getpid();
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.
189 dag_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
191 unsigned int processed = 0;
192 int flags = p->md.dag_offset_flags;
193 unsigned int nonblocking = flags & DAGF_NONBLOCK;
197 /* Get the next bufferful of packets (if necessary). */
198 while (p->md.dag_mem_top - p->md.dag_mem_bottom < dag_record_size) {
201 * Has "pcap_breakloop()" been called?
205 * Yes - clear the flag that indicates that
206 * it has, and return -2 to indicate that
207 * we were told to break out of the loop.
213 p->md.dag_mem_top = dag_offset(p->fd, &(p->md.dag_mem_bottom), flags);
214 if (nonblocking && (p->md.dag_mem_top - p->md.dag_mem_bottom < dag_record_size))
216 /* Pcap is configured to process only available packets, and there aren't any. */
221 /* Process the packets. */
222 while (p->md.dag_mem_top - p->md.dag_mem_bottom >= dag_record_size) {
224 unsigned short packet_len = 0;
226 struct pcap_pkthdr pcap_header;
228 dag_record_t *header = (dag_record_t *)(p->md.dag_mem_base + p->md.dag_mem_bottom);
229 u_char *dp = ((u_char *)header) + dag_record_size;
233 * Has "pcap_breakloop()" been called?
237 * Yes - clear the flag that indicates that
238 * it has, and return -2 to indicate that
239 * we were told to break out of the loop.
245 rlen = ntohs(header->rlen);
246 if (rlen < dag_record_size)
248 strncpy(p->errbuf, "dag_read: record too small", PCAP_ERRBUF_SIZE);
251 p->md.dag_mem_bottom += rlen;
253 switch(header->type) {
256 if (header->type == TYPE_AAL5) {
257 packet_len = ntohs(header->wlen);
258 caplen = rlen - dag_record_size;
260 caplen = packet_len = ATM_CELL_SIZE;
262 if (p->linktype == DLT_SUNATM) {
263 struct sunatm_hdr *sunatm = (struct sunatm_hdr *)dp;
264 unsigned long rawatm;
266 rawatm = ntohl(*((unsigned long *)dp));
267 sunatm->vci = htons((rawatm >> 4) & 0xffff);
268 sunatm->vpi = (rawatm >> 20) & 0x00ff;
269 sunatm->flags = ((header->flags.iface & 1) ? 0x80 : 0x00) |
270 ((sunatm->vpi == 0 && sunatm->vci == htons(5)) ? 6 :
271 ((sunatm->vpi == 0 && sunatm->vci == htons(16)) ? 5 :
272 ((dp[ATM_HDR_SIZE] == 0xaa &&
273 dp[ATM_HDR_SIZE+1] == 0xaa &&
274 dp[ATM_HDR_SIZE+2] == 0x03) ? 2 : 1)));
277 packet_len -= ATM_HDR_SIZE;
278 caplen -= ATM_HDR_SIZE;
284 packet_len = ntohs(header->wlen);
285 packet_len -= (p->md.dag_fcs_bits >> 3);
286 caplen = rlen - dag_record_size - 2;
287 if (caplen > packet_len) {
294 packet_len = ntohs(header->wlen);
295 packet_len -= (p->md.dag_fcs_bits >> 3);
296 caplen = rlen - dag_record_size;
297 if (caplen > packet_len) {
303 if (caplen > p->snapshot)
304 caplen = p->snapshot;
306 /* Count lost packets. */
308 if (p->md.stat.ps_drop > (UINT_MAX - ntohs(header->lctr))) {
309 p->md.stat.ps_drop = UINT_MAX;
311 p->md.stat.ps_drop += ntohs(header->lctr);
315 /* Run the packet filter if there is one. */
316 if ((p->fcode.bf_insns == NULL) || bpf_filter(p->fcode.bf_insns, dp, packet_len, caplen)) {
318 /* convert between timestamp formats */
319 register unsigned long long ts;
321 if (IS_BIGENDIAN()) {
322 ts = SWAP_TS(header->ts);
327 pcap_header.ts.tv_sec = ts >> 32;
328 ts = (ts & 0xffffffffULL) * 1000000;
329 ts += 0x80000000; /* rounding */
330 pcap_header.ts.tv_usec = ts >> 32;
331 if (pcap_header.ts.tv_usec >= 1000000) {
332 pcap_header.ts.tv_usec -= 1000000;
333 pcap_header.ts.tv_sec++;
336 /* Fill in our own header data */
337 pcap_header.caplen = caplen;
338 pcap_header.len = packet_len;
340 /* Count the packet. */
341 p->md.stat.ps_recv++;
343 /* Call the user supplied callback function */
344 callback(user, &pcap_header, dp);
346 /* Only count packets that pass the filter, for consistency with standard Linux behaviour. */
348 if (processed == cnt)
350 /* Reached the user-specified limit. */
356 if (nonblocking || processed)
366 dag_inject(pcap_t *p, const void *buf _U_, size_t size _U_)
368 strlcpy(p->errbuf, "Sending packets isn't supported on DAG cards",
374 * Get a handle for a live capture from the given DAG device. Passing a NULL
375 * device will result in a failure. The promisc flag is ignored because DAG
376 * cards are always promiscuous. The to_ms parameter is also ignored as it is
377 * not supported in hardware.
382 dag_open_live(const char *device, int snaplen, int promisc, int to_ms, char *ebuf)
384 char conf[30]; /* dag configure string */
390 if (device == NULL) {
391 snprintf(ebuf, PCAP_ERRBUF_SIZE, "device is NULL: %s", pcap_strerror(errno));
394 /* Allocate a handle for this session. */
396 handle = malloc(sizeof(*handle));
397 if (handle == NULL) {
398 snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc %s: %s", device, pcap_strerror(errno));
402 /* Initialize some components of the pcap structure. */
404 memset(handle, 0, sizeof(*handle));
406 if (strstr(device, "/dev") == NULL) {
407 char * newDev = (char *)malloc(strlen(device) + 6);
409 strcat(newDev, "/dev/");
410 strcat(newDev,device);
413 device = strdup(device);
416 if (device == NULL) {
417 snprintf(ebuf, PCAP_ERRBUF_SIZE, "str_dup: %s\n", pcap_strerror(errno));
421 /* setup device parameters */
422 if((handle->fd = dag_open((char *)device)) < 0) {
423 snprintf(ebuf, PCAP_ERRBUF_SIZE, "dag_open %s: %s", device, pcap_strerror(errno));
427 /* set the card snap length to the specified snaplen parameter */
428 if (snaplen == 0 || snaplen > MAX_DAG_SNAPLEN) {
429 snaplen = MAX_DAG_SNAPLEN;
430 } else if (snaplen < MIN_DAG_SNAPLEN) {
431 snaplen = MIN_DAG_SNAPLEN;
433 /* snap len has to be a multiple of 4 */
434 snprintf(conf, 30, "varlen slen=%d", (snaplen + 3) & ~3);
436 if(dag_configure(handle->fd, conf) < 0) {
437 snprintf(ebuf, PCAP_ERRBUF_SIZE,"dag_configure %s: %s\n", device, pcap_strerror(errno));
441 if((handle->md.dag_mem_base = dag_mmap(handle->fd)) == MAP_FAILED) {
442 snprintf(ebuf, PCAP_ERRBUF_SIZE,"dag_mmap %s: %s\n", device, pcap_strerror(errno));
446 if(dag_start(handle->fd) < 0) {
447 snprintf(ebuf, PCAP_ERRBUF_SIZE, "dag_start %s: %s\n", device, pcap_strerror(errno));
452 * Important! You have to ensure bottom is properly
453 * initialized to zero on startup, it won't give you
454 * a compiler warning if you make this mistake!
456 handle->md.dag_mem_bottom = 0;
457 handle->md.dag_mem_top = 0;
458 handle->md.dag_fcs_bits = 32;
460 /* Query the card first for special cases. */
461 daginf = dag_info(handle->fd);
462 if ((0x4200 == daginf->device_code) || (0x4230 == daginf->device_code))
464 /* DAG 4.2S and 4.23S already strip the FCS. Stripping the final word again truncates the packet. */
465 handle->md.dag_fcs_bits = 0;
468 /* Then allow an environment variable to override. */
469 if ((s = getenv("ERF_FCS_BITS")) != NULL) {
470 if ((n = atoi(s)) == 0 || n == 16|| n == 32) {
471 handle->md.dag_fcs_bits = n;
473 snprintf(ebuf, PCAP_ERRBUF_SIZE,
474 "pcap_open_live %s: bad ERF_FCS_BITS value (%d) in environment\n", device, n);
479 handle->snapshot = snaplen;
480 /*handle->md.timeout = to_ms; */
482 handle->linktype = -1;
483 if (dag_get_datalink(handle) < 0) {
484 strcpy(ebuf, handle->errbuf);
490 if (new_pcap_dag(handle) < 0) {
491 snprintf(ebuf, PCAP_ERRBUF_SIZE, "new_pcap_dag %s: %s\n", device, pcap_strerror(errno));
496 * "select()" and "poll()" don't (yet) work on DAG device descriptors.
498 handle->selectable_fd = -1;
501 handle->md.device = (char *)device;
503 free((char *)device);
507 handle->read_op = dag_read;
508 handle->inject_op = dag_inject;
509 handle->setfilter_op = dag_setfilter;
510 handle->set_datalink_op = dag_set_datalink;
511 handle->getnonblock_op = pcap_getnonblock_fd;
512 handle->setnonblock_op = dag_setnonblock;
513 handle->stats_op = dag_stats;
514 handle->close_op = dag_platform_close;
519 if (device != NULL) {
520 free((char *)device);
522 if (handle != NULL) {
524 * Get rid of any link-layer type list we allocated.
526 if (handle->dlt_list != NULL) {
527 free(handle->dlt_list);
536 dag_stats(pcap_t *p, struct pcap_stat *ps) {
537 /* This needs to be filled out correctly. Hopefully a dagapi call will
538 provide all necessary information.
540 /*p->md.stat.ps_recv = 0;*/
541 /*p->md.stat.ps_drop = 0;*/
549 * Get from "/proc/dag" all interfaces listed there; if they're
550 * already in the list of interfaces we have, that won't add another
551 * instance, but if they're not, that'll add them.
553 * We don't bother getting any addresses for them.
555 * We also don't fail if we couldn't open "/proc/dag"; we just leave
556 * the list of interfaces as is.
559 dag_platform_finddevs(pcap_if_t **devlistp, char *errbuf)
565 char name[512]; /* XXX - pick a size */
569 /* Quick exit if /proc/dag not readable */
570 proc_dag_f = fopen("/proc/dag", "r");
571 if (proc_dag_f == NULL)
574 char dev[16] = "dagx";
576 for (i = '0'; ret == 0 && i <= '9'; i++) {
578 if (pcap_add_if(devlistp, dev, 0, NULL, errbuf) == -1) {
589 for (linenum = 1; fgets(linebuf, sizeof linebuf, proc_dag_f) != NULL; linenum++) {
592 * Skip the first two lines - they're headers.
599 if (*p == '\0' || *p == '\n' || *p != 'D')
600 continue; /* not a Dag line */
603 * Get the interface name.
606 while (*p != '\0' && *p != ':') {
608 *q++ = tolower(*p++);
615 * Add an entry for this interface, with no addresses.
617 p[strlen(p) - 1] = '\0'; /* get rid of \n */
618 if (pcap_add_if(devlistp, name, 0, strdup(p + 2), errbuf) == -1) {
628 * Well, we didn't fail for any other reason; did we
629 * fail due to an error reading the file?
631 if (ferror(proc_dag_f)) {
632 (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
633 "Error reading /proc/dag: %s",
634 pcap_strerror(errno));
639 (void)fclose(proc_dag_f);
644 * Installs the given bpf filter program in the given pcap structure. There is
645 * no attempt to store the filter in kernel memory as that is not supported
649 dag_setfilter(pcap_t *p, struct bpf_program *fp)
654 strncpy(p->errbuf, "setfilter: No filter specified",
659 /* Make our private copy of the filter */
661 if (install_bpf_program(p, fp) < 0)
670 dag_set_datalink(pcap_t *p, int dlt)
678 dag_setnonblock(pcap_t *p, int nonblock, char *errbuf)
681 * Set non-blocking mode on the FD.
682 * XXX - is that necessary? If not, don't bother calling it,
683 * and have a "dag_getnonblock()" function that looks at
684 * "p->md.dag_offset_flags".
686 if (pcap_setnonblock_fd(p, nonblock, errbuf) < 0)
690 p->md.dag_offset_flags |= DAGF_NONBLOCK;
692 p->md.dag_offset_flags &= ~DAGF_NONBLOCK;
698 dag_get_datalink(pcap_t *p)
702 if (p->dlt_list == NULL && (p->dlt_list = malloc(2*sizeof(*(p->dlt_list)))) == NULL) {
703 (void)snprintf(p->errbuf, sizeof(p->errbuf), "malloc: %s", pcap_strerror(errno));
707 /* Check the type through a dagapi call. */
708 daglinktype = dag_linktype(p->fd);
710 switch(daglinktype) {
713 if (p->dlt_list != NULL) {
715 p->dlt_list[0] = DLT_CHDLC;
716 p->dlt_list[1] = DLT_PPP_SERIAL;
718 p->linktype = DLT_CHDLC;
723 * This is (presumably) a real Ethernet capture; give it a
724 * link-layer-type list with DLT_EN10MB and DLT_DOCSIS, so
725 * that an application can let you choose it, in case you're
726 * capturing DOCSIS traffic that a Cisco Cable Modem
727 * Termination System is putting out onto an Ethernet (it
728 * doesn't put an Ethernet header onto the wire, it puts raw
729 * DOCSIS frames out on the wire inside the low-level
732 if (p->dlt_list != NULL) {
734 p->dlt_list[0] = DLT_EN10MB;
735 p->dlt_list[1] = DLT_DOCSIS;
737 p->linktype = DLT_EN10MB;
742 if (p->dlt_list != NULL) {
744 p->dlt_list[0] = DLT_ATM_RFC1483;
745 p->dlt_list[1] = DLT_SUNATM;
747 p->linktype = DLT_ATM_RFC1483;
752 p->linktype = DLT_NULL;
756 snprintf(p->errbuf, sizeof(p->errbuf), "unknown DAG linktype %d\n", daglinktype);