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[libpcap] / pcap-win32.c
1 /*
2 * Copyright (c) 1999 - 2005 NetGroup, Politecnico di Torino (Italy)
3 * Copyright (c) 2005 - 2006 CACE Technologies, Davis (California)
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the Politecnico di Torino, CACE Technologies
16 * nor the names of its contributors may be used to endorse or promote
17 * products derived from this software without specific prior written
18 * permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
23 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
24 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
25 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
26 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
30 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 *
32 */
33
34 #ifndef lint
35 static const char rcsid[] _U_ =
36 "@(#) $Header: /tcpdump/master/libpcap/pcap-win32.c,v 1.25.2.4 2006-02-22 17:09:32 gianluca Exp $ (LBL)";
37 #endif
38
39 #include <pcap-int.h>
40 #include <Packet32.h>
41 #include <Ntddndis.h>
42 #ifdef HAVE_DAG_API
43 #include <dagnew.h>
44 #include <dagapi.h>
45 #endif /* HAVE_DAG_API */
46 #ifdef __MINGW32__
47 int* _errno();
48 #define errno (*_errno())
49 #endif /* __MINGW32__ */
50
51 static int pcap_setfilter_win32_npf(pcap_t *, struct bpf_program *);
52 static int pcap_setfilter_win32_dag(pcap_t *, struct bpf_program *);
53 static int pcap_getnonblock_win32(pcap_t *, char *);
54 static int pcap_setnonblock_win32(pcap_t *, int, char *);
55
56 #define PcapBufSize 256000 /*dimension of the buffer in the pcap_t structure*/
57 #define SIZE_BUF 1000000
58
59 /* Equivalent to ntohs(), but a lot faster under Windows */
60 #define SWAPS(_X) ((_X & 0xff) << 8) | (_X >> 8)
61
62 /*
63 * Header that the WinPcap driver associates to the packets.
64 * Once was in bpf.h
65 */
66 struct bpf_hdr {
67 struct timeval bh_tstamp; /* time stamp */
68 bpf_u_int32 bh_caplen; /* length of captured portion */
69 bpf_u_int32 bh_datalen; /* original length of packet */
70 u_short bh_hdrlen; /* length of bpf header (this struct
71 plus alignment padding) */
72 };
73
74 /* Start winsock */
75 int
76 wsockinit()
77 {
78 WORD wVersionRequested;
79 WSADATA wsaData;
80 int err;
81 wVersionRequested = MAKEWORD( 1, 1);
82 err = WSAStartup( wVersionRequested, &wsaData );
83 if ( err != 0 )
84 {
85 return -1;
86 }
87 return 0;
88 }
89
90
91 static int
92 pcap_stats_win32(pcap_t *p, struct pcap_stat *ps)
93 {
94
95 if(PacketGetStats(p->adapter, (struct bpf_stat*)ps) != TRUE){
96 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "PacketGetStats error: %s", pcap_win32strerror());
97 return -1;
98 }
99
100 return 0;
101 }
102
103 static int
104 pcap_read_win32_npf(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
105 {
106 int cc;
107 int n = 0;
108 register u_char *bp, *ep;
109
110 cc = p->cc;
111 if (p->cc == 0) {
112 /*
113 * Has "pcap_breakloop()" been called?
114 */
115 if (p->break_loop) {
116 /*
117 * Yes - clear the flag that indicates that it
118 * has, and return -2 to indicate that we were
119 * told to break out of the loop.
120 */
121 p->break_loop = 0;
122 return (-2);
123 }
124
125 /* capture the packets */
126 if(PacketReceivePacket(p->adapter,p->Packet,TRUE)==FALSE){
127 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "read error: PacketReceivePacket failed");
128 return (-1);
129 }
130
131 cc = p->Packet->ulBytesReceived;
132
133 bp = p->Packet->Buffer;
134 }
135 else
136 bp = p->bp;
137
138 /*
139 * Loop through each packet.
140 */
141 #define bhp ((struct bpf_hdr *)bp)
142 ep = bp + cc;
143 while (1) {
144 register int caplen, hdrlen;
145
146 /*
147 * Has "pcap_breakloop()" been called?
148 * If so, return immediately - if we haven't read any
149 * packets, clear the flag and return -2 to indicate
150 * that we were told to break out of the loop, otherwise
151 * leave the flag set, so that the *next* call will break
152 * out of the loop without having read any packets, and
153 * return the number of packets we've processed so far.
154 */
155 if (p->break_loop) {
156 if (n == 0) {
157 p->break_loop = 0;
158 return (-2);
159 } else {
160 p->bp = bp;
161 p->cc = ep - bp;
162 return (n);
163 }
164 }
165 if (bp >= ep)
166 break;
167
168 caplen = bhp->bh_caplen;
169 hdrlen = bhp->bh_hdrlen;
170
171 /*
172 * XXX A bpf_hdr matches a pcap_pkthdr.
173 */
174 (*callback)(user, (struct pcap_pkthdr*)bp, bp + hdrlen);
175 bp += BPF_WORDALIGN(caplen + hdrlen);
176 if (++n >= cnt && cnt > 0) {
177 p->bp = bp;
178 p->cc = ep - bp;
179 return (n);
180 }
181 }
182 #undef bhp
183 p->cc = 0;
184 return (n);
185 }
186
187 #ifdef HAVE_DAG_API
188 static int
189 pcap_read_win32_dag(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
190 {
191 u_char *dp = NULL;
192 int packet_len = 0, caplen = 0;
193 struct pcap_pkthdr pcap_header;
194 u_char *endofbuf;
195 int n = 0;
196 dag_record_t *header;
197 unsigned erf_record_len;
198 ULONGLONG ts;
199 int cc;
200 unsigned swt;
201 unsigned dfp = p->adapter->DagFastProcess;
202
203 cc = p->cc;
204 if (cc == 0) /* Get new packets only if we have processed all the ones of the previous read */
205 {
206 /* Get new packets from the network */
207 if(PacketReceivePacket(p->adapter, p->Packet, TRUE)==FALSE){
208 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "read error: PacketReceivePacket failed");
209 return (-1);
210 }
211
212 cc = p->Packet->ulBytesReceived;
213 if(cc == 0)
214 /* The timeout has expired but we no packets arrived */
215 return 0;
216 header = (dag_record_t*)p->adapter->DagBuffer;
217 }
218 else
219 header = (dag_record_t*)p->bp;
220
221 endofbuf = (char*)header + cc;
222
223 /*
224 * Cycle through the packets
225 */
226 do
227 {
228 erf_record_len = SWAPS(header->rlen);
229 if((char*)header + erf_record_len > endofbuf)
230 break;
231
232 /* Increase the number of captured packets */
233 p->md.stat.ps_recv++;
234
235 /* Find the beginning of the packet */
236 dp = ((u_char *)header) + dag_record_size;
237
238 /* Determine actual packet len */
239 switch(header->type)
240 {
241 case TYPE_ATM:
242 packet_len = ATM_SNAPLEN;
243 caplen = ATM_SNAPLEN;
244 dp += 4;
245
246 break;
247
248 case TYPE_ETH:
249 swt = SWAPS(header->wlen);
250 packet_len = swt - (p->md.dag_fcs_bits);
251 caplen = erf_record_len - dag_record_size - 2;
252 if (caplen > packet_len)
253 {
254 caplen = packet_len;
255 }
256 dp += 2;
257
258 break;
259
260 case TYPE_HDLC_POS:
261 swt = SWAPS(header->wlen);
262 packet_len = swt - (p->md.dag_fcs_bits);
263 caplen = erf_record_len - dag_record_size;
264 if (caplen > packet_len)
265 {
266 caplen = packet_len;
267 }
268
269 break;
270 }
271
272 if(caplen > p->snapshot)
273 caplen = p->snapshot;
274
275 /*
276 * Has "pcap_breakloop()" been called?
277 * If so, return immediately - if we haven't read any
278 * packets, clear the flag and return -2 to indicate
279 * that we were told to break out of the loop, otherwise
280 * leave the flag set, so that the *next* call will break
281 * out of the loop without having read any packets, and
282 * return the number of packets we've processed so far.
283 */
284 if (p->break_loop)
285 {
286 if (n == 0)
287 {
288 p->break_loop = 0;
289 return (-2);
290 }
291 else
292 {
293 p->bp = (char*)header;
294 p->cc = endofbuf - (char*)header;
295 return (n);
296 }
297 }
298
299 if(!dfp)
300 {
301 /* convert between timestamp formats */
302 ts = header->ts;
303 pcap_header.ts.tv_sec = (int)(ts >> 32);
304 ts = (ts & 0xffffffffi64) * 1000000;
305 ts += 0x80000000; /* rounding */
306 pcap_header.ts.tv_usec = (int)(ts >> 32);
307 if (pcap_header.ts.tv_usec >= 1000000) {
308 pcap_header.ts.tv_usec -= 1000000;
309 pcap_header.ts.tv_sec++;
310 }
311 }
312
313 /* No underlaying filtering system. We need to filter on our own */
314 if (p->fcode.bf_insns)
315 {
316 if (bpf_filter(p->fcode.bf_insns, dp, packet_len, caplen) == 0)
317 {
318 /* Move to next packet */
319 header = (dag_record_t*)((char*)header + erf_record_len);
320 continue;
321 }
322 }
323
324 /* Fill the header for the user suppplied callback function */
325 pcap_header.caplen = caplen;
326 pcap_header.len = packet_len;
327
328 /* Call the callback function */
329 (*callback)(user, &pcap_header, dp);
330
331 /* Move to next packet */
332 header = (dag_record_t*)((char*)header + erf_record_len);
333
334 /* Stop if the number of packets requested by user has been reached*/
335 if (++n >= cnt && cnt > 0)
336 {
337 p->bp = (char*)header;
338 p->cc = endofbuf - (char*)header;
339 return (n);
340 }
341 }
342 while((u_char*)header < endofbuf);
343
344 return 1;
345 }
346 #endif /* HAVE_DAG_API */
347
348 /* Send a packet to the network */
349 static int
350 pcap_inject_win32(pcap_t *p, const void *buf, size_t size){
351 LPPACKET PacketToSend;
352
353 PacketToSend=PacketAllocatePacket();
354
355 if (PacketToSend == NULL)
356 {
357 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "send error: PacketAllocatePacket failed");
358 return -1;
359 }
360
361 PacketInitPacket(PacketToSend,(PVOID)buf,size);
362 if(PacketSendPacket(p->adapter,PacketToSend,TRUE) == FALSE){
363 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "send error: PacketSendPacket failed");
364 PacketFreePacket(PacketToSend);
365 return -1;
366 }
367
368 PacketFreePacket(PacketToSend);
369
370 /*
371 * We assume it all got sent if "PacketSendPacket()" succeeded.
372 * "pcap_inject()" is expected to return the number of bytes
373 * sent.
374 */
375 return size;
376 }
377
378 static void
379 pcap_close_win32(pcap_t *p)
380 {
381 pcap_close_common(p);
382 if (p->adapter != NULL) {
383 PacketCloseAdapter(p->adapter);
384 p->adapter = NULL;
385 }
386 if (p->Packet) {
387 PacketFreePacket(p->Packet);
388 p->Packet = NULL;
389 }
390 }
391
392 pcap_t *
393 pcap_open_live(const char *device, int snaplen, int promisc, int to_ms,
394 char *ebuf)
395 {
396 register pcap_t *p;
397 NetType type;
398
399 /* Init WinSock */
400 wsockinit();
401
402 p = (pcap_t *)malloc(sizeof(*p));
403 if (p == NULL)
404 {
405 snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc: %s", pcap_strerror(errno));
406 return (NULL);
407 }
408 memset(p, 0, sizeof(*p));
409 p->adapter=NULL;
410
411 p->adapter = PacketOpenAdapter((char*)device);
412
413 if (p->adapter == NULL)
414 {
415 free(p);
416 /* Adapter detected but we are not able to open it. Return failure. */
417 snprintf(ebuf, PCAP_ERRBUF_SIZE, "Error opening adapter: %s", pcap_win32strerror());
418 return NULL;
419 }
420
421 /*get network type*/
422 if(PacketGetNetType (p->adapter,&type) == FALSE)
423 {
424 snprintf(ebuf, PCAP_ERRBUF_SIZE, "Cannot determine the network type: %s", pcap_win32strerror());
425 goto bad;
426 }
427
428 /*Set the linktype*/
429 switch (type.LinkType)
430 {
431 case NdisMediumWan:
432 p->linktype = DLT_EN10MB;
433 break;
434
435 case NdisMedium802_3:
436 p->linktype = DLT_EN10MB;
437 /*
438 * This is (presumably) a real Ethernet capture; give it a
439 * link-layer-type list with DLT_EN10MB and DLT_DOCSIS, so
440 * that an application can let you choose it, in case you're
441 * capturing DOCSIS traffic that a Cisco Cable Modem
442 * Termination System is putting out onto an Ethernet (it
443 * doesn't put an Ethernet header onto the wire, it puts raw
444 * DOCSIS frames out on the wire inside the low-level
445 * Ethernet framing).
446 */
447 p->dlt_list = (u_int *) malloc(sizeof(u_int) * 2);
448 /*
449 * If that fails, just leave the list empty.
450 */
451 if (p->dlt_list != NULL) {
452 p->dlt_list[0] = DLT_EN10MB;
453 p->dlt_list[1] = DLT_DOCSIS;
454 p->dlt_count = 2;
455 }
456 break;
457
458 case NdisMediumFddi:
459 p->linktype = DLT_FDDI;
460 break;
461
462 case NdisMedium802_5:
463 p->linktype = DLT_IEEE802;
464 break;
465
466 case NdisMediumArcnetRaw:
467 p->linktype = DLT_ARCNET;
468 break;
469
470 case NdisMediumArcnet878_2:
471 p->linktype = DLT_ARCNET;
472 break;
473
474 case NdisMediumAtm:
475 p->linktype = DLT_ATM_RFC1483;
476 break;
477
478 case NdisMediumCHDLC:
479 p->linktype = DLT_CHDLC;
480 break;
481
482 case NdisMediumPPPSerial:
483 p->linktype = DLT_PPP_SERIAL;
484 break;
485
486 case NdisMediumNull:
487 p->linktype = DLT_NULL;
488 break;
489
490 default:
491 p->linktype = DLT_EN10MB; /*an unknown adapter is assumed to be ethernet*/
492 break;
493 }
494
495 /* Set promisquous mode */
496 if (promisc) PacketSetHwFilter(p->adapter,NDIS_PACKET_TYPE_PROMISCUOUS);
497 else PacketSetHwFilter(p->adapter,NDIS_PACKET_TYPE_ALL_LOCAL);
498
499 /* Set the buffer size */
500 p->bufsize = PcapBufSize;
501
502 /* Store the timeout. Used by pcap_setnonblock() */
503 p->timeout= to_ms;
504
505 /* allocate Packet structure used during the capture */
506 if((p->Packet = PacketAllocatePacket())==NULL)
507 {
508 snprintf(ebuf, PCAP_ERRBUF_SIZE, "failed to allocate the PACKET structure");
509 goto bad;
510 }
511
512 if(!(p->adapter->Flags & INFO_FLAG_DAG_CARD))
513 {
514 /*
515 * Traditional Adapter
516 */
517
518 p->buffer = (u_char *)malloc(PcapBufSize);
519 if (p->buffer == NULL)
520 {
521 snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc: %s", pcap_strerror(errno));
522 goto bad;
523 }
524
525 PacketInitPacket(p->Packet,(BYTE*)p->buffer,p->bufsize);
526
527 p->snapshot = snaplen;
528
529 /* allocate the standard buffer in the driver */
530 if(PacketSetBuff( p->adapter, SIZE_BUF)==FALSE)
531 {
532 snprintf(ebuf, PCAP_ERRBUF_SIZE,"driver error: not enough memory to allocate the kernel buffer\n");
533 goto bad;
534 }
535
536 /* tell the driver to copy the buffer only if it contains at least 16K */
537 if(PacketSetMinToCopy(p->adapter,16000)==FALSE)
538 {
539 snprintf(ebuf, PCAP_ERRBUF_SIZE,"Error calling PacketSetMinToCopy: %s\n", pcap_win32strerror());
540 goto bad;
541 }
542 }
543 else
544 #ifdef HAVE_DAG_API
545 {
546 /*
547 * Dag Card
548 */
549 LONG status;
550 HKEY dagkey;
551 DWORD lptype;
552 DWORD lpcbdata;
553 int postype = 0;
554 char keyname[512];
555
556 snprintf(keyname, sizeof(keyname), "%s\\CardParams\\%s",
557 "SYSTEM\\CurrentControlSet\\Services\\DAG",
558 strstr(_strlwr((char*)device), "dag"));
559 do
560 {
561 status = RegOpenKeyEx(HKEY_LOCAL_MACHINE, keyname, 0, KEY_READ, &dagkey);
562 if(status != ERROR_SUCCESS)
563 break;
564
565 status = RegQueryValueEx(dagkey,
566 "PosType",
567 NULL,
568 &lptype,
569 (char*)&postype,
570 &lpcbdata);
571
572 if(status != ERROR_SUCCESS)
573 {
574 postype = 0;
575 }
576
577 RegCloseKey(dagkey);
578 }
579 while(FALSE);
580
581
582 p->snapshot = PacketSetSnapLen(p->adapter, snaplen);
583
584 /* Set the length of the FCS associated to any packet. This value
585 * will be subtracted to the packet length */
586 p->md.dag_fcs_bits = p->adapter->DagFcsLen;
587 }
588 #else
589 goto bad;
590 #endif /* HAVE_DAG_API */
591
592 PacketSetReadTimeout(p->adapter, to_ms);
593
594 #ifdef HAVE_DAG_API
595 if(p->adapter->Flags & INFO_FLAG_DAG_CARD)
596 {
597 /* install dag specific handlers for read and setfilter */
598 p->read_op = pcap_read_win32_dag;
599 p->setfilter_op = pcap_setfilter_win32_dag;
600 }
601 else
602 {
603 #endif /* HAVE_DAG_API */
604 /* install traditional npf handlers for read and setfilter */
605 p->read_op = pcap_read_win32_npf;
606 p->setfilter_op = pcap_setfilter_win32_npf;
607 #ifdef HAVE_DAG_API
608 }
609 #endif /* HAVE_DAG_API */
610 p->setdirection_op = NULL; /* Not implemented. */
611 /* XXX - can this be implemented on some versions of Windows? */
612 p->inject_op = pcap_inject_win32;
613 p->set_datalink_op = NULL; /* can't change data link type */
614 p->getnonblock_op = pcap_getnonblock_win32;
615 p->setnonblock_op = pcap_setnonblock_win32;
616 p->stats_op = pcap_stats_win32;
617 p->close_op = pcap_close_win32;
618
619 return (p);
620 bad:
621 if (p->adapter)
622 PacketCloseAdapter(p->adapter);
623 if (p->buffer != NULL)
624 free(p->buffer);
625 if(p->Packet)
626 PacketFreePacket(p->Packet);
627 /*
628 * Get rid of any link-layer type list we allocated.
629 */
630 if (p->dlt_list != NULL)
631 free(p->dlt_list);
632 free(p);
633 return (NULL);
634 }
635
636
637 static int
638 pcap_setfilter_win32_npf(pcap_t *p, struct bpf_program *fp)
639 {
640 if(PacketSetBpf(p->adapter,fp)==FALSE){
641 /*
642 * Kernel filter not installed.
643 * XXX - fall back on userland filtering, as is done
644 * on other platforms?
645 */
646 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "Driver error: cannot set bpf filter: %s", pcap_win32strerror());
647 return (-1);
648 }
649
650 /*
651 * Discard any previously-received packets, as they might have
652 * passed whatever filter was formerly in effect, but might
653 * not pass this filter (BIOCSETF discards packets buffered
654 * in the kernel, so you can lose packets in any case).
655 */
656 p->cc = 0;
657 return (0);
658 }
659
660 /*
661 * We filter at user level, since the kernel driver does't process the packets
662 */
663 static int
664 pcap_setfilter_win32_dag(pcap_t *p, struct bpf_program *fp) {
665
666 if(!fp)
667 {
668 strncpy(p->errbuf, "setfilter: No filter specified", sizeof(p->errbuf));
669 return -1;
670 }
671
672 /* Install a user level filter */
673 if (install_bpf_program(p, fp) < 0)
674 {
675 snprintf(p->errbuf, sizeof(p->errbuf),
676 "setfilter, unable to install the filter: %s", pcap_strerror(errno));
677 return -1;
678 }
679
680 p->md.use_bpf = 0;
681
682 return (0);
683 }
684
685 static int
686 pcap_getnonblock_win32(pcap_t *p, char *errbuf)
687 {
688 /*
689 * XXX - if there were a PacketGetReadTimeout() call, we
690 * would use it, and return 1 if the timeout is -1
691 * and 0 otherwise.
692 */
693 return (p->nonblock);
694 }
695
696 static int
697 pcap_setnonblock_win32(pcap_t *p, int nonblock, char *errbuf)
698 {
699 int newtimeout;
700
701 if (nonblock) {
702 /*
703 * Set the read timeout to -1 for non-blocking mode.
704 */
705 newtimeout = -1;
706 } else {
707 /*
708 * Restore the timeout set when the device was opened.
709 * (Note that this may be -1, in which case we're not
710 * really leaving non-blocking mode.)
711 */
712 newtimeout = p->timeout;
713 }
714 if (!PacketSetReadTimeout(p->adapter, newtimeout)) {
715 snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
716 "PacketSetReadTimeout: %s", pcap_win32strerror());
717 return (-1);
718 }
719 p->nonblock = (newtimeout == -1);
720 return (0);
721 }
722
723 /* Set the driver working mode */
724 int
725 pcap_setmode(pcap_t *p, int mode){
726
727 if (p->adapter==NULL)
728 {
729 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "impossible to set mode while reading from a file");
730 return -1;
731 }
732
733 if(PacketSetMode(p->adapter,mode)==FALSE)
734 {
735 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "driver error: working mode not recognized");
736 return -1;
737 }
738
739 return 0;
740 }
741
742 /* Set the dimension of the kernel-level capture buffer */
743 int
744 pcap_setbuff(pcap_t *p, int dim)
745 {
746 if (p->adapter==NULL)
747 {
748 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "The kernel buffer size cannot be set while reading from a file");
749 return -1;
750 }
751
752 if(PacketSetBuff(p->adapter,dim)==FALSE)
753 {
754 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "driver error: not enough memory to allocate the kernel buffer");
755 return -1;
756 }
757 return 0;
758 }
759
760 /*set the minimum amount of data that will release a read call*/
761 int
762 pcap_setmintocopy(pcap_t *p, int size)
763 {
764 if (p->adapter==NULL)
765 {
766 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "Impossible to set the mintocopy parameter on an offline capture");
767 return -1;
768 }
769
770 if(PacketSetMinToCopy(p->adapter, size)==FALSE)
771 {
772 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "driver error: unable to set the requested mintocopy size");
773 return -1;
774 }
775 return 0;
776 }