pcap-win32.c revision 147894
1/* 2 * Copyright (c) 1999 - 2003 3 * NetGroup, Politecnico di Torino (Italy) 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 nor the names of its 16 * contributors may be used to endorse or promote products derived from 17 * this software without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 22 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 23 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 24 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 25 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 29 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 * 31 */ 32 33#ifndef lint 34static const char rcsid[] _U_ = 35 "@(#) $Header: /tcpdump/master/libpcap/pcap-win32.c,v 1.25.2.2 2005/06/10 03:48:56 risso Exp $ (LBL)"; 36#endif 37 38#include <pcap-int.h> 39#include <packet32.h> 40#include <Ntddndis.h> 41#ifdef HAVE_DAG_API 42#include <dagnew.h> 43#include <dagapi.h> 44#endif /* HAVE_DAG_API */ 45#ifdef __MINGW32__ 46int* _errno(); 47#define errno (*_errno()) 48#endif /* __MINGW32__ */ 49 50static int pcap_setfilter_win32_npf(pcap_t *, struct bpf_program *); 51static int pcap_setfilter_win32_dag(pcap_t *, struct bpf_program *); 52static int pcap_getnonblock_win32(pcap_t *, char *); 53static int pcap_setnonblock_win32(pcap_t *, int, char *); 54 55#define PcapBufSize 256000 /*dimension of the buffer in the pcap_t structure*/ 56#define SIZE_BUF 1000000 57 58/* Equivalent to ntohs(), but a lot faster under Windows */ 59#define SWAPS(_X) ((_X & 0xff) << 8) | (_X >> 8) 60 61/* 62 * Header that the WinPcap driver associates to the packets. 63 * Once was in bpf.h 64 */ 65struct bpf_hdr { 66 struct timeval bh_tstamp; /* time stamp */ 67 bpf_u_int32 bh_caplen; /* length of captured portion */ 68 bpf_u_int32 bh_datalen; /* original length of packet */ 69 u_short bh_hdrlen; /* length of bpf header (this struct 70 plus alignment padding) */ 71}; 72 73/* Start winsock */ 74int 75wsockinit() 76{ 77 WORD wVersionRequested; 78 WSADATA wsaData; 79 int err; 80 wVersionRequested = MAKEWORD( 1, 1); 81 err = WSAStartup( wVersionRequested, &wsaData ); 82 if ( err != 0 ) 83 { 84 return -1; 85 } 86 return 0; 87} 88 89 90static int 91pcap_stats_win32(pcap_t *p, struct pcap_stat *ps) 92{ 93 94 if(PacketGetStats(p->adapter, (struct bpf_stat*)ps) != TRUE){ 95 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "PacketGetStats error: %s", pcap_win32strerror()); 96 return -1; 97 } 98 99 return 0; 100} 101 102static int 103pcap_read_win32_npf(pcap_t *p, int cnt, pcap_handler callback, u_char *user) 104{ 105 int cc; 106 int n = 0; 107 register u_char *bp, *ep; 108 109 cc = p->cc; 110 if (p->cc == 0) { 111 /* 112 * Has "pcap_breakloop()" been called? 113 */ 114 if (p->break_loop) { 115 /* 116 * Yes - clear the flag that indicates that it 117 * has, and return -2 to indicate that we were 118 * told to break out of the loop. 119 */ 120 p->break_loop = 0; 121 return (-2); 122 } 123 124 /* capture the packets */ 125 if(PacketReceivePacket(p->adapter,p->Packet,TRUE)==FALSE){ 126 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "read error: PacketReceivePacket failed"); 127 return (-1); 128 } 129 130 cc = p->Packet->ulBytesReceived; 131 132 bp = p->Packet->Buffer; 133 } 134 else 135 bp = p->bp; 136 137 /* 138 * Loop through each packet. 139 */ 140#define bhp ((struct bpf_hdr *)bp) 141 ep = bp + cc; 142 while (1) { 143 register int caplen, hdrlen; 144 145 /* 146 * Has "pcap_breakloop()" been called? 147 * If so, return immediately - if we haven't read any 148 * packets, clear the flag and return -2 to indicate 149 * that we were told to break out of the loop, otherwise 150 * leave the flag set, so that the *next* call will break 151 * out of the loop without having read any packets, and 152 * return the number of packets we've processed so far. 153 */ 154 if (p->break_loop) { 155 if (n == 0) { 156 p->break_loop = 0; 157 return (-2); 158 } else { 159 p->bp = bp; 160 p->cc = ep - bp; 161 return (n); 162 } 163 } 164 if (bp >= ep) 165 break; 166 167 caplen = bhp->bh_caplen; 168 hdrlen = bhp->bh_hdrlen; 169 170 /* 171 * XXX A bpf_hdr matches a pcap_pkthdr. 172 */ 173 (*callback)(user, (struct pcap_pkthdr*)bp, bp + hdrlen); 174 bp += BPF_WORDALIGN(caplen + hdrlen); 175 if (++n >= cnt && cnt > 0) { 176 p->bp = bp; 177 p->cc = ep - bp; 178 return (n); 179 } 180 } 181#undef bhp 182 p->cc = 0; 183 return (n); 184} 185 186#ifdef HAVE_DAG_API 187static int 188pcap_read_win32_dag(pcap_t *p, int cnt, pcap_handler callback, u_char *user) 189{ 190 u_char *dp = NULL; 191 int packet_len = 0, caplen = 0; 192 struct pcap_pkthdr pcap_header; 193 u_char *endofbuf; 194 int n = 0; 195 dag_record_t *header; 196 unsigned erf_record_len; 197 ULONGLONG ts; 198 int cc; 199 unsigned swt; 200 unsigned dfp = p->adapter->DagFastProcess; 201 202 cc = p->cc; 203 if (cc == 0) /* Get new packets only if we have processed all the ones of the previous read */ 204 { 205 /* Get new packets from the network */ 206 if(PacketReceivePacket(p->adapter, p->Packet, TRUE)==FALSE){ 207 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "read error: PacketReceivePacket failed"); 208 return (-1); 209 } 210 211 cc = p->Packet->ulBytesReceived; 212 if(cc == 0) 213 /* The timeout has expired but we no packets arrived */ 214 return 0; 215 header = (dag_record_t*)p->adapter->DagBuffer; 216 } 217 else 218 header = (dag_record_t*)p->bp; 219 220 endofbuf = (char*)header + cc; 221 222 /* 223 * Cycle through the packets 224 */ 225 do 226 { 227 erf_record_len = SWAPS(header->rlen); 228 if((char*)header + erf_record_len > endofbuf) 229 break; 230 231 /* Increase the number of captured packets */ 232 p->md.stat.ps_recv++; 233 234 /* Find the beginning of the packet */ 235 dp = ((u_char *)header) + dag_record_size; 236 237 /* Determine actual packet len */ 238 switch(header->type) 239 { 240 case TYPE_ATM: 241 packet_len = ATM_SNAPLEN; 242 caplen = ATM_SNAPLEN; 243 dp += 4; 244 245 break; 246 247 case TYPE_ETH: 248 swt = SWAPS(header->wlen); 249 packet_len = swt - (p->md.dag_fcs_bits); 250 caplen = erf_record_len - dag_record_size - 2; 251 if (caplen > packet_len) 252 { 253 caplen = packet_len; 254 } 255 dp += 2; 256 257 break; 258 259 case TYPE_HDLC_POS: 260 swt = SWAPS(header->wlen); 261 packet_len = swt - (p->md.dag_fcs_bits); 262 caplen = erf_record_len - dag_record_size; 263 if (caplen > packet_len) 264 { 265 caplen = packet_len; 266 } 267 268 break; 269 } 270 271 if(caplen > p->snapshot) 272 caplen = p->snapshot; 273 274 /* 275 * Has "pcap_breakloop()" been called? 276 * If so, return immediately - if we haven't read any 277 * packets, clear the flag and return -2 to indicate 278 * that we were told to break out of the loop, otherwise 279 * leave the flag set, so that the *next* call will break 280 * out of the loop without having read any packets, and 281 * return the number of packets we've processed so far. 282 */ 283 if (p->break_loop) 284 { 285 if (n == 0) 286 { 287 p->break_loop = 0; 288 return (-2); 289 } 290 else 291 { 292 p->bp = (char*)header; 293 p->cc = endofbuf - (char*)header; 294 return (n); 295 } 296 } 297 298 if(!dfp) 299 { 300 /* convert between timestamp formats */ 301 ts = header->ts; 302 pcap_header.ts.tv_sec = (int)(ts >> 32); 303 ts = (ts & 0xffffffffi64) * 1000000; 304 ts += 0x80000000; /* rounding */ 305 pcap_header.ts.tv_usec = (int)(ts >> 32); 306 if (pcap_header.ts.tv_usec >= 1000000) { 307 pcap_header.ts.tv_usec -= 1000000; 308 pcap_header.ts.tv_sec++; 309 } 310 } 311 312 /* No underlaying filtering system. We need to filter on our own */ 313 if (p->fcode.bf_insns) 314 { 315 if (bpf_filter(p->fcode.bf_insns, dp, packet_len, caplen) == 0) 316 { 317 /* Move to next packet */ 318 header = (dag_record_t*)((char*)header + erf_record_len); 319 continue; 320 } 321 } 322 323 /* Fill the header for the user suppplied callback function */ 324 pcap_header.caplen = caplen; 325 pcap_header.len = packet_len; 326 327 /* Call the callback function */ 328 (*callback)(user, &pcap_header, dp); 329 330 /* Move to next packet */ 331 header = (dag_record_t*)((char*)header + erf_record_len); 332 333 /* Stop if the number of packets requested by user has been reached*/ 334 if (++n >= cnt && cnt > 0) 335 { 336 p->bp = (char*)header; 337 p->cc = endofbuf - (char*)header; 338 return (n); 339 } 340 } 341 while((u_char*)header < endofbuf); 342 343 return 1; 344} 345#endif /* HAVE_DAG_API */ 346 347/* Send a packet to the network */ 348static int 349pcap_inject_win32(pcap_t *p, const void *buf, size_t size){ 350 LPPACKET PacketToSend; 351 352 PacketToSend=PacketAllocatePacket(); 353 354 if (PacketToSend == NULL) 355 { 356 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "send error: PacketAllocatePacket failed"); 357 return -1; 358 } 359 360 PacketInitPacket(PacketToSend,(PVOID)buf,size); 361 if(PacketSendPacket(p->adapter,PacketToSend,TRUE) == FALSE){ 362 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "send error: PacketSendPacket failed"); 363 PacketFreePacket(PacketToSend); 364 return -1; 365 } 366 367 PacketFreePacket(PacketToSend); 368 369 /* 370 * We assume it all got sent if "PacketSendPacket()" succeeded. 371 * "pcap_inject()" is expected to return the number of bytes 372 * sent. 373 */ 374 return size; 375} 376 377static void 378pcap_close_win32(pcap_t *p) 379{ 380 pcap_close_common(p); 381 if (p->adapter != NULL) { 382 PacketCloseAdapter(p->adapter); 383 p->adapter = NULL; 384 } 385 if (p->Packet) { 386 PacketFreePacket(p->Packet); 387 p->Packet = NULL; 388 } 389} 390 391pcap_t * 392pcap_open_live(const char *device, int snaplen, int promisc, int to_ms, 393 char *ebuf) 394{ 395 register pcap_t *p; 396 NetType type; 397 398 /* Init WinSock */ 399 wsockinit(); 400 401 p = (pcap_t *)malloc(sizeof(*p)); 402 if (p == NULL) 403 { 404 snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc: %s", pcap_strerror(errno)); 405 return (NULL); 406 } 407 memset(p, 0, sizeof(*p)); 408 p->adapter=NULL; 409 410 p->adapter = PacketOpenAdapter((char*)device); 411 412 if (p->adapter == NULL) 413 { 414 free(p); 415 /* Adapter detected but we are not able to open it. Return failure. */ 416 snprintf(ebuf, PCAP_ERRBUF_SIZE, "Error opening adapter: %s", pcap_win32strerror()); 417 return NULL; 418 } 419 420 /*get network type*/ 421 if(PacketGetNetType (p->adapter,&type) == FALSE) 422 { 423 snprintf(ebuf, PCAP_ERRBUF_SIZE, "Cannot determine the network type: %s", pcap_win32strerror()); 424 goto bad; 425 } 426 427 /*Set the linktype*/ 428 switch (type.LinkType) 429 { 430 case NdisMediumWan: 431 p->linktype = DLT_EN10MB; 432 break; 433 434 case NdisMedium802_3: 435 p->linktype = DLT_EN10MB; 436 /* 437 * This is (presumably) a real Ethernet capture; give it a 438 * link-layer-type list with DLT_EN10MB and DLT_DOCSIS, so 439 * that an application can let you choose it, in case you're 440 * capturing DOCSIS traffic that a Cisco Cable Modem 441 * Termination System is putting out onto an Ethernet (it 442 * doesn't put an Ethernet header onto the wire, it puts raw 443 * DOCSIS frames out on the wire inside the low-level 444 * Ethernet framing). 445 */ 446 p->dlt_list = (u_int *) malloc(sizeof(u_int) * 2); 447 /* 448 * If that fails, just leave the list empty. 449 */ 450 if (p->dlt_list != NULL) { 451 p->dlt_list[0] = DLT_EN10MB; 452 p->dlt_list[1] = DLT_DOCSIS; 453 p->dlt_count = 2; 454 } 455 break; 456 457 case NdisMediumFddi: 458 p->linktype = DLT_FDDI; 459 break; 460 461 case NdisMedium802_5: 462 p->linktype = DLT_IEEE802; 463 break; 464 465 case NdisMediumArcnetRaw: 466 p->linktype = DLT_ARCNET; 467 break; 468 469 case NdisMediumArcnet878_2: 470 p->linktype = DLT_ARCNET; 471 break; 472 473 case NdisMediumAtm: 474 p->linktype = DLT_ATM_RFC1483; 475 break; 476 477 case NdisMediumCHDLC: 478 p->linktype = DLT_CHDLC; 479 break; 480 481 case NdisMediumPPPSerial: 482 p->linktype = DLT_PPP_SERIAL; 483 break; 484 485 case NdisMediumNull: 486 p->linktype = DLT_NULL; 487 break; 488 489 default: 490 p->linktype = DLT_EN10MB; /*an unknown adapter is assumed to be ethernet*/ 491 break; 492 } 493 494 /* Set promisquous mode */ 495 if (promisc) PacketSetHwFilter(p->adapter,NDIS_PACKET_TYPE_PROMISCUOUS); 496 else PacketSetHwFilter(p->adapter,NDIS_PACKET_TYPE_ALL_LOCAL); 497 498 /* Set the buffer size */ 499 p->bufsize = PcapBufSize; 500 501 /* allocate Packet structure used during the capture */ 502 if((p->Packet = PacketAllocatePacket())==NULL) 503 { 504 snprintf(ebuf, PCAP_ERRBUF_SIZE, "failed to allocate the PACKET structure"); 505 goto bad; 506 } 507 508 if(!(p->adapter->Flags & INFO_FLAG_DAG_CARD)) 509 { 510 /* 511 * Traditional Adapter 512 */ 513 514 p->buffer = (u_char *)malloc(PcapBufSize); 515 if (p->buffer == NULL) 516 { 517 snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc: %s", pcap_strerror(errno)); 518 goto bad; 519 } 520 521 PacketInitPacket(p->Packet,(BYTE*)p->buffer,p->bufsize); 522 523 p->snapshot = snaplen; 524 525 /* allocate the standard buffer in the driver */ 526 if(PacketSetBuff( p->adapter, SIZE_BUF)==FALSE) 527 { 528 snprintf(ebuf, PCAP_ERRBUF_SIZE,"driver error: not enough memory to allocate the kernel buffer\n"); 529 goto bad; 530 } 531 532 /* tell the driver to copy the buffer only if it contains at least 16K */ 533 if(PacketSetMinToCopy(p->adapter,16000)==FALSE) 534 { 535 snprintf(ebuf, PCAP_ERRBUF_SIZE,"Error calling PacketSetMinToCopy: %s\n", pcap_win32strerror()); 536 goto bad; 537 } 538 } 539 else 540#ifdef HAVE_DAG_API 541 { 542 /* 543 * Dag Card 544 */ 545 LONG status; 546 HKEY dagkey; 547 DWORD lptype; 548 DWORD lpcbdata; 549 int postype = 0; 550 char keyname[512]; 551 552 snprintf(keyname, sizeof(keyname), "%s\\CardParams\\%s", 553 "SYSTEM\\CurrentControlSet\\Services\\DAG", 554 strstr(_strlwr((char*)device), "dag")); 555 do 556 { 557 status = RegOpenKeyEx(HKEY_LOCAL_MACHINE, keyname, 0, KEY_READ, &dagkey); 558 if(status != ERROR_SUCCESS) 559 break; 560 561 status = RegQueryValueEx(dagkey, 562 "PosType", 563 NULL, 564 &lptype, 565 (char*)&postype, 566 &lpcbdata); 567 568 if(status != ERROR_SUCCESS) 569 { 570 postype = 0; 571 } 572 573 RegCloseKey(dagkey); 574 } 575 while(FALSE); 576 577 578 p->snapshot = PacketSetSnapLen(p->adapter, snaplen); 579 580 /* Set the length of the FCS associated to any packet. This value 581 * will be subtracted to the packet length */ 582 p->md.dag_fcs_bits = p->adapter->DagFcsLen; 583 } 584#else 585 goto bad; 586#endif /* HAVE_DAG_API */ 587 588 PacketSetReadTimeout(p->adapter, to_ms); 589 590#ifdef HAVE_DAG_API 591 if(p->adapter->Flags & INFO_FLAG_DAG_CARD) 592 { 593 /* install dag specific handlers for read and setfilter */ 594 p->read_op = pcap_read_win32_dag; 595 p->setfilter_op = pcap_setfilter_win32_dag; 596 } 597 else 598 { 599#endif /* HAVE_DAG_API */ 600 /* install traditional npf handlers for read and setfilter */ 601 p->read_op = pcap_read_win32_npf; 602 p->setfilter_op = pcap_setfilter_win32_npf; 603#ifdef HAVE_DAG_API 604 } 605#endif /* HAVE_DAG_API */ 606 p->setdirection_op = NULL; /* Not implemented. */ 607 /* XXX - can this be implemented on some versions of Windows? */ 608 p->inject_op = pcap_inject_win32; 609 p->set_datalink_op = NULL; /* can't change data link type */ 610 p->getnonblock_op = pcap_getnonblock_win32; 611 p->setnonblock_op = pcap_setnonblock_win32; 612 p->stats_op = pcap_stats_win32; 613 p->close_op = pcap_close_win32; 614 615 return (p); 616bad: 617 if (p->adapter) 618 PacketCloseAdapter(p->adapter); 619 if (p->buffer != NULL) 620 free(p->buffer); 621 if(p->Packet) 622 PacketFreePacket(p->Packet); 623 /* 624 * Get rid of any link-layer type list we allocated. 625 */ 626 if (p->dlt_list != NULL) 627 free(p->dlt_list); 628 free(p); 629 return (NULL); 630} 631 632 633static int 634pcap_setfilter_win32_npf(pcap_t *p, struct bpf_program *fp) 635{ 636 if(PacketSetBpf(p->adapter,fp)==FALSE){ 637 /* 638 * Kernel filter not installed. 639 * XXX - fall back on userland filtering, as is done 640 * on other platforms? 641 */ 642 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "Driver error: cannot set bpf filter: %s", pcap_win32strerror()); 643 return (-1); 644 } 645 646 /* 647 * Discard any previously-received packets, as they might have 648 * passed whatever filter was formerly in effect, but might 649 * not pass this filter (BIOCSETF discards packets buffered 650 * in the kernel, so you can lose packets in any case). 651 */ 652 p->cc = 0; 653 return (0); 654} 655 656/* 657 * We filter at user level, since the kernel driver does't process the packets 658 */ 659static int 660pcap_setfilter_win32_dag(pcap_t *p, struct bpf_program *fp) { 661 662 if(!fp) 663 { 664 strncpy(p->errbuf, "setfilter: No filter specified", sizeof(p->errbuf)); 665 return -1; 666 } 667 668 /* Install a user level filter */ 669 if (install_bpf_program(p, fp) < 0) 670 { 671 snprintf(p->errbuf, sizeof(p->errbuf), 672 "setfilter, unable to install the filter: %s", pcap_strerror(errno)); 673 return -1; 674 } 675 676 p->md.use_bpf = 0; 677 678 return (0); 679} 680 681static int 682pcap_getnonblock_win32(pcap_t *p, char *errbuf) 683{ 684 /* 685 * XXX - if there were a PacketGetReadTimeout() call, we 686 * would use it, and return 1 if the timeout is -1 687 * and 0 otherwise. 688 */ 689 return (p->nonblock); 690} 691 692static int 693pcap_setnonblock_win32(pcap_t *p, int nonblock, char *errbuf) 694{ 695 int newtimeout; 696 697 if (nonblock) { 698 /* 699 * Set the read timeout to -1 for non-blocking mode. 700 */ 701 newtimeout = -1; 702 } else { 703 /* 704 * Restore the timeout set when the device was opened. 705 * (Note that this may be -1, in which case we're not 706 * really leaving non-blocking mode.) 707 */ 708 newtimeout = p->timeout; 709 } 710 if (!PacketSetReadTimeout(p->adapter, newtimeout)) { 711 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, 712 "PacketSetReadTimeout: %s", pcap_win32strerror()); 713 return (-1); 714 } 715 p->nonblock = (newtimeout == -1); 716 return (0); 717} 718 719/* Set the driver working mode */ 720int 721pcap_setmode(pcap_t *p, int mode){ 722 723 if (p->adapter==NULL) 724 { 725 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "impossible to set mode while reading from a file"); 726 return -1; 727 } 728 729 if(PacketSetMode(p->adapter,mode)==FALSE) 730 { 731 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "driver error: working mode not recognized"); 732 return -1; 733 } 734 735 return 0; 736} 737 738/* Set the dimension of the kernel-level capture buffer */ 739int 740pcap_setbuff(pcap_t *p, int dim) 741{ 742 if (p->adapter==NULL) 743 { 744 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "The kernel buffer size cannot be set while reading from a file"); 745 return -1; 746 } 747 748 if(PacketSetBuff(p->adapter,dim)==FALSE) 749 { 750 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "driver error: not enough memory to allocate the kernel buffer"); 751 return -1; 752 } 753 return 0; 754} 755 756/*set the minimum amount of data that will release a read call*/ 757int 758pcap_setmintocopy(pcap_t *p, int size) 759{ 760 if (p->adapter==NULL) 761 { 762 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "Impossible to set the mintocopy parameter on an offline capture"); 763 return -1; 764 } 765 766 if(PacketSetMinToCopy(p->adapter, size)==FALSE) 767 { 768 snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "driver error: unable to set the requested mintocopy size"); 769 return -1; 770 } 771 return 0; 772} 773