The Tcpdump Group git mirrors - libpcap/blob - pcap-int.h

   1 /*
   2  * Copyright (c) 1994, 1995, 1996
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the Computer Systems
  16  *      Engineering Group at Lawrence Berkeley Laboratory.
  17  * 4. Neither the name of the University nor of the Laboratory may be used
  18  *    to endorse or promote products derived from this software without
  19  *    specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #ifndef pcap_int_h
  35 #define pcap_int_h
  36
  37 #include <pcap/pcap.h>
  38
  39 #ifdef __cplusplus
  40 extern "C" {
  41 #endif
  42
  43 #ifdef MSDOS
  44   #include <fcntl.h>
  45   #include <io.h>
  46 #endif
  47
  48 #if (defined(_MSC_VER) && (_MSC_VER <= 1200)) /* we are compiling with Visual Studio 6, that doesn't support the LL suffix*/
  49
  50 /*
  51  * Swap byte ordering of unsigned long long timestamp on a big endian
  52  * machine.
  53  */
  54 #define SWAPLL(ull)  ((ull & 0xff00000000000000) >> 56) | \
  55                       ((ull & 0x00ff000000000000) >> 40) | \
  56                       ((ull & 0x0000ff0000000000) >> 24) | \
  57                       ((ull & 0x000000ff00000000) >> 8)  | \
  58                       ((ull & 0x00000000ff000000) << 8)  | \
  59                       ((ull & 0x0000000000ff0000) << 24) | \
  60                       ((ull & 0x000000000000ff00) << 40) | \
  61                       ((ull & 0x00000000000000ff) << 56)
  62
  63 #else /* A recent Visual studio compiler or not VC */
  64
  65 /*
  66  * Swap byte ordering of unsigned long long timestamp on a big endian
  67  * machine.
  68  */
  69 #define SWAPLL(ull)  ((ull & 0xff00000000000000ULL) >> 56) | \
  70                       ((ull & 0x00ff000000000000ULL) >> 40) | \
  71                       ((ull & 0x0000ff0000000000ULL) >> 24) | \
  72                       ((ull & 0x000000ff00000000ULL) >> 8)  | \
  73                       ((ull & 0x00000000ff000000ULL) << 8)  | \
  74                       ((ull & 0x0000000000ff0000ULL) << 24) | \
  75                       ((ull & 0x000000000000ff00ULL) << 40) | \
  76                       ((ull & 0x00000000000000ffULL) << 56)
  77
  78 #endif /* _MSC_VER */
  79
  80 /*
  81  * Maximum snapshot length.
  82  *
  83  * Somewhat arbitrary, but chosen to be:
  84  *
  85  *    1) big enough for maximum-size Linux loopback packets (65549)
  86  *       and some USB packets captured with USBPcap:
  87  *
  88  *           http://desowin.org/usbpcap/
  89  *
  90  *       (> 131072, < 262144)
  91  *
  92  * and
  93  *
  94  *    2) small enough not to cause attempts to allocate huge amounts of
  95  *       memory; some applications might use the snapshot length in a
  96  *       savefile header to control the size of the buffer they allocate,
  97  *       so a size of, say, 2^31-1 might not work well.
  98  *
  99  * We don't enforce this in pcap_set_snaplen(), but we use it internally.
 100  */
 101 #define MAXIMUM_SNAPLEN         262144
 102
 103 struct pcap_opt {
 104         char    *device;
 105         int     timeout;        /* timeout for buffering */
 106         u_int   buffer_size;
 107         int     promisc;
 108         int     rfmon;          /* monitor mode */
 109         int     immediate;      /* immediate mode - deliver packets as soon as they arrive */
 110         int     nonblock;       /* non-blocking mode - don't wait for packets to be delivered, return "no packets available" */
 111         int     tstamp_type;
 112         int     tstamp_precision;
 113
 114         /*
 115          * Platform-dependent options.
 116          */
 117 #ifdef __linux__
 118         int     protocol;       /* protocol to use when creating PF_PACKET socket */
 119 #endif
 120 #ifdef _WIN32
 121         int     nocapture_local;/* disable NPF loopback */
 122 #endif
 123 };
 124
 125 typedef int     (*activate_op_t)(pcap_t *);
 126 typedef int     (*can_set_rfmon_op_t)(pcap_t *);
 127 typedef int     (*read_op_t)(pcap_t *, int cnt, pcap_handler, u_char *);
 128 typedef int     (*inject_op_t)(pcap_t *, const void *, size_t);
 129 typedef void    (*save_current_filter_op_t)(pcap_t *, const char *);
 130 typedef int     (*setfilter_op_t)(pcap_t *, struct bpf_program *);
 131 typedef int     (*setdirection_op_t)(pcap_t *, pcap_direction_t);
 132 typedef int     (*set_datalink_op_t)(pcap_t *, int);
 133 typedef int     (*getnonblock_op_t)(pcap_t *);
 134 typedef int     (*setnonblock_op_t)(pcap_t *, int);
 135 typedef int     (*stats_op_t)(pcap_t *, struct pcap_stat *);
 136 #ifdef _WIN32
 137 typedef struct pcap_stat *(*stats_ex_op_t)(pcap_t *, int *);
 138 typedef int     (*setbuff_op_t)(pcap_t *, int);
 139 typedef int     (*setmode_op_t)(pcap_t *, int);
 140 typedef int     (*setmintocopy_op_t)(pcap_t *, int);
 141 typedef HANDLE  (*getevent_op_t)(pcap_t *);
 142 typedef int     (*oid_get_request_op_t)(pcap_t *, bpf_u_int32, void *, size_t *);
 143 typedef int     (*oid_set_request_op_t)(pcap_t *, bpf_u_int32, const void *, size_t *);
 144 typedef u_int   (*sendqueue_transmit_op_t)(pcap_t *, pcap_send_queue *, int);
 145 typedef int     (*setuserbuffer_op_t)(pcap_t *, int);
 146 typedef int     (*live_dump_op_t)(pcap_t *, char *, int, int);
 147 typedef int     (*live_dump_ended_op_t)(pcap_t *, int);
 148 typedef PAirpcapHandle  (*get_airpcap_handle_op_t)(pcap_t *);
 149 #endif
 150 typedef void    (*cleanup_op_t)(pcap_t *);
 151
 152 /*
 153  * We put all the stuff used in the read code path at the beginning,
 154  * to try to keep it together in the same cache line or lines.
 155  */
 156 struct pcap {
 157         /*
 158          * Method to call to read packets on a live capture.
 159          */
 160         read_op_t read_op;
 161
 162         /*
 163          * Method to call to read packets from a savefile.
 164          */
 165         int (*next_packet_op)(pcap_t *, struct pcap_pkthdr *, u_char **);
 166
 167 #ifdef _WIN32
 168         HANDLE handle;
 169 #else
 170         int fd;
 171         int selectable_fd;
 172 #endif /* _WIN32 */
 173
 174         /*
 175          * Read buffer.
 176          */
 177         u_int bufsize;
 178         void *buffer;
 179         u_char *bp;
 180         int cc;
 181
 182         int break_loop;         /* flag set to force break from packet-reading loop */
 183
 184         void *priv;             /* private data for methods */
 185
 186 #ifdef HAVE_REMOTE
 187         struct pcap_samp rmt_samp;      /* parameters related to the sampling process. */
 188 #endif
 189
 190         int swapped;
 191         FILE *rfile;            /* null if live capture, non-null if savefile */
 192         u_int fddipad;
 193         struct pcap *next;      /* list of open pcaps that need stuff cleared on close */
 194
 195         /*
 196          * File version number; meaningful only for a savefile, but we
 197          * keep it here so that apps that (mistakenly) ask for the
 198          * version numbers will get the same zero values that they
 199          * always did.
 200          */
 201         int version_major;
 202         int version_minor;
 203
 204         int snapshot;
 205         int linktype;           /* Network linktype */
 206         int linktype_ext;       /* Extended information stored in the linktype field of a file */
 207         int tzoff;              /* timezone offset */
 208         int offset;             /* offset for proper alignment */
 209         int activated;          /* true if the capture is really started */
 210         int oldstyle;           /* if we're opening with pcap_open_live() */
 211
 212         struct pcap_opt opt;
 213
 214         /*
 215          * Place holder for pcap_next().
 216          */
 217         u_char *pkt;
 218
 219 #ifdef _WIN32
 220         struct pcap_stat stat;          /* used for pcap_stats_ex() */
 221 #endif
 222
 223         /* We're accepting only packets in this direction/these directions. */
 224         pcap_direction_t direction;
 225
 226         /*
 227          * Flags to affect BPF code generation.
 228          */
 229         int bpf_codegen_flags;
 230
 231         /*
 232          * Placeholder for filter code if bpf not in kernel.
 233          */
 234         struct bpf_program fcode;
 235
 236         char errbuf[PCAP_ERRBUF_SIZE + 1];
 237         int dlt_count;
 238         u_int *dlt_list;
 239         int tstamp_type_count;
 240         u_int *tstamp_type_list;
 241         int tstamp_precision_count;
 242         u_int *tstamp_precision_list;
 243
 244         struct pcap_pkthdr pcap_header; /* This is needed for the pcap_next_ex() to work */
 245
 246         /*
 247          * More methods.
 248          */
 249         activate_op_t activate_op;
 250         can_set_rfmon_op_t can_set_rfmon_op;
 251         inject_op_t inject_op;
 252         save_current_filter_op_t save_current_filter_op;
 253         setfilter_op_t setfilter_op;
 254         setdirection_op_t setdirection_op;
 255         set_datalink_op_t set_datalink_op;
 256         getnonblock_op_t getnonblock_op;
 257         setnonblock_op_t setnonblock_op;
 258         stats_op_t stats_op;
 259
 260         /*
 261          * Routine to use as callback for pcap_next()/pcap_next_ex().
 262          */
 263         pcap_handler oneshot_callback;
 264
 265 #ifdef _WIN32
 266         /*
 267          * These are, at least currently, specific to the Win32 NPF
 268          * driver.
 269          */
 270         stats_ex_op_t stats_ex_op;
 271         setbuff_op_t setbuff_op;
 272         setmode_op_t setmode_op;
 273         setmintocopy_op_t setmintocopy_op;
 274         getevent_op_t getevent_op;
 275         oid_get_request_op_t oid_get_request_op;
 276         oid_set_request_op_t oid_set_request_op;
 277         sendqueue_transmit_op_t sendqueue_transmit_op;
 278         setuserbuffer_op_t setuserbuffer_op;
 279         live_dump_op_t live_dump_op;
 280         live_dump_ended_op_t live_dump_ended_op;
 281         get_airpcap_handle_op_t get_airpcap_handle_op;
 282 #endif
 283         cleanup_op_t cleanup_op;
 284 };
 285
 286 /*
 287  * BPF code generation flags.
 288  */
 289 #define BPF_SPECIAL_VLAN_HANDLING       0x00000001      /* special VLAN handling for Linux */
 290
 291 /*
 292  * This is a timeval as stored in a savefile.
 293  * It has to use the same types everywhere, independent of the actual
 294  * `struct timeval'; `struct timeval' has 32-bit tv_sec values on some
 295  * platforms and 64-bit tv_sec values on other platforms, and writing
 296  * out native `struct timeval' values would mean files could only be
 297  * read on systems with the same tv_sec size as the system on which
 298  * the file was written.
 299  */
 300
 301 struct pcap_timeval {
 302     bpf_int32 tv_sec;           /* seconds */
 303     bpf_int32 tv_usec;          /* microseconds */
 304 };
 305
 306 /*
 307  * This is a `pcap_pkthdr' as actually stored in a savefile.
 308  *
 309  * Do not change the format of this structure, in any way (this includes
 310  * changes that only affect the length of fields in this structure),
 311  * and do not make the time stamp anything other than seconds and
 312  * microseconds (e.g., seconds and nanoseconds).  Instead:
 313  *
 314  *      introduce a new structure for the new format;
 315  *
 316  *      send mail to "tcpdump-workers@lists.tcpdump.org", requesting
 317  *      a new magic number for your new capture file format, and, when
 318  *      you get the new magic number, put it in "savefile.c";
 319  *
 320  *      use that magic number for save files with the changed record
 321  *      header;
 322  *
 323  *      make the code in "savefile.c" capable of reading files with
 324  *      the old record header as well as files with the new record header
 325  *      (using the magic number to determine the header format).
 326  *
 327  * Then supply the changes by forking the branch at
 328  *
 329  *      https://github.com/the-tcpdump-group/libpcap/issues
 330  *
 331  * and issuing a pull request, so that future versions of libpcap and
 332  * programs that use it (such as tcpdump) will be able to read your new
 333  * capture file format.
 334  */
 335
 336 struct pcap_sf_pkthdr {
 337     struct pcap_timeval ts;     /* time stamp */
 338     bpf_u_int32 caplen;         /* length of portion present */
 339     bpf_u_int32 len;            /* length this packet (off wire) */
 340 };
 341
 342 /*
 343  * How a `pcap_pkthdr' is actually stored in savefiles written
 344  * by some patched versions of libpcap (e.g. the ones in Red
 345  * Hat Linux 6.1 and 6.2).
 346  *
 347  * Do not change the format of this structure, in any way (this includes
 348  * changes that only affect the length of fields in this structure).
 349  * Instead, introduce a new structure, as per the above.
 350  */
 351
 352 struct pcap_sf_patched_pkthdr {
 353     struct pcap_timeval ts;     /* time stamp */
 354     bpf_u_int32 caplen;         /* length of portion present */
 355     bpf_u_int32 len;            /* length this packet (off wire) */
 356     int         index;
 357     unsigned short protocol;
 358     unsigned char pkt_type;
 359 };
 360
 361 /*
 362  * User data structure for the one-shot callback used for pcap_next()
 363  * and pcap_next_ex().
 364  */
 365 struct oneshot_userdata {
 366         struct pcap_pkthdr *hdr;
 367         const u_char **pkt;
 368         pcap_t *pd;
 369 };
 370
 371 #ifndef min
 372 #define min(a, b) ((a) > (b) ? (b) : (a))
 373 #endif
 374
 375 int     pcap_offline_read(pcap_t *, int, pcap_handler, u_char *);
 376
 377 #include <stdarg.h>
 378
 379 #include "portability.h"
 380
 381 /*
 382  * Does the packet count argument to a module's read routine say
 383  * "supply packets until you run out of packets"?
 384  */
 385 #define PACKET_COUNT_IS_UNLIMITED(count)        ((count) <= 0)
 386
 387 /*
 388  * Routines that most pcap implementations can use for non-blocking mode.
 389  */
 390 #if !defined(_WIN32) && !defined(MSDOS)
 391 int     pcap_getnonblock_fd(pcap_t *);
 392 int     pcap_setnonblock_fd(pcap_t *p, int);
 393 #endif
 394
 395 /*
 396  * Internal interfaces for "pcap_lib_version()".
 397  *
 398  * "pcap_platform_lib_version()" returns platform-specific version
 399  * information, or NULL if there isn't any.
 400  */
 401 const char *pcap_platform_lib_version(void);
 402
 403 /*
 404  * Internal interfaces for "pcap_create()".
 405  *
 406  * "pcap_create_interface()" is the routine to do a pcap_create on
 407  * a regular network interface.  There are multiple implementations
 408  * of this, one for each platform type (Linux, BPF, DLPI, etc.),
 409  * with the one used chosen by the configure script.
 410  *
 411  * "pcap_create_common()" allocates and fills in a pcap_t, for use
 412  * by pcap_create routines.
 413  */
 414 pcap_t  *pcap_create_interface(const char *, char *);
 415 pcap_t  *pcap_create_common(char *, size_t);
 416 int     pcap_do_addexit(pcap_t *);
 417 void    pcap_add_to_pcaps_to_close(pcap_t *);
 418 void    pcap_remove_from_pcaps_to_close(pcap_t *);
 419 void    pcap_cleanup_live_common(pcap_t *);
 420 int     pcap_check_activated(pcap_t *);
 421
 422 /*
 423  * Internal interfaces for "pcap_findalldevs()".
 424  *
 425  * A pcap_if_list_t * is a reference to a list of devices.
 426  *
 427  * "pcap_platform_finddevs()" is the platform-dependent routine to
 428  * find local network interfaces.
 429  *
 430  * "pcap_findalldevs_interfaces()" is a helper to find those interfaces
 431  * using the "standard" mechanisms (SIOCGIFCONF, "getifaddrs()", etc.).
 432  *
 433  * "add_dev()" adds an entry to a pcap_if_list_t.
 434  *
 435  * "find_dev()" tries to find a device, by name, in a pcap_if_list_t.
 436  *
 437  * "find_or_add_dev()" checks whether a device is already in a pcap_if_list_t
 438  * and, if not, adds an entry for it.
 439  */
 440 struct pcap_if_list;
 441 typedef struct pcap_if_list pcap_if_list_t;
 442 int     pcap_platform_finddevs(pcap_if_list_t *, char *);
 443 #if !defined(_WIN32) && !defined(MSDOS)
 444 int     pcap_findalldevs_interfaces(pcap_if_list_t *, char *,
 445             int (*)(const char *));
 446 #endif
 447 pcap_if_t *find_or_add_dev(pcap_if_list_t *, const char *, bpf_u_int32,
 448             const char *, char *);
 449 pcap_if_t *find_dev(pcap_if_list_t *, const char *);
 450 pcap_if_t *add_dev(pcap_if_list_t *, const char *, bpf_u_int32, const char *,
 451             char *);
 452 int     add_addr_to_dev(pcap_if_t *, struct sockaddr *, size_t,
 453             struct sockaddr *, size_t, struct sockaddr *, size_t,
 454             struct sockaddr *dstaddr, size_t, char *errbuf);
 455 #ifndef _WIN32
 456 pcap_if_t *find_or_add_if(pcap_if_list_t *, const char *, bpf_u_int32,
 457             char *);
 458 int     add_addr_to_if(pcap_if_list_t *, const char *, bpf_u_int32,
 459             struct sockaddr *, size_t, struct sockaddr *, size_t,
 460             struct sockaddr *, size_t, struct sockaddr *, size_t, char *);
 461 #endif
 462
 463 /*
 464  * Internal interfaces for "pcap_open_offline()".
 465  *
 466  * "pcap_open_offline_common()" allocates and fills in a pcap_t, for use
 467  * by pcap_open_offline routines.
 468  *
 469  * "sf_cleanup()" closes the file handle associated with a pcap_t, if
 470  * appropriate, and frees all data common to all modules for handling
 471  * savefile types.
 472  */
 473 pcap_t  *pcap_open_offline_common(char *ebuf, size_t size);
 474 void    sf_cleanup(pcap_t *p);
 475
 476 /*
 477  * Internal interfaces for both "pcap_create()" and routines that
 478  * open savefiles.
 479  *
 480  * "pcap_oneshot()" is the standard one-shot callback for "pcap_next()"
 481  * and "pcap_next_ex()".
 482  */
 483 void    pcap_oneshot(u_char *, const struct pcap_pkthdr *, const u_char *);
 484
 485 #ifdef _WIN32
 486 void    pcap_win32_err_to_str(DWORD, char *);
 487 #endif
 488
 489 int     install_bpf_program(pcap_t *, struct bpf_program *);
 490
 491 int     pcap_strcasecmp(const char *, const char *);
 492
 493 #ifdef __cplusplus
 494 }
 495 #endif
 496
 497 #endif