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 #if defined(_WIN32)
  44   /*
  45    * Make sure Packet32.h doesn't define BPF structures that we've
  46    * probably already defined as a result of including <pcap/pcap.h>.
  47    */
  48   #define BPF_MAJOR_VERSION
  49   #include <Packet32.h>
  50 #elif defined(MSDOS)
  51   #include <fcntl.h>
  52   #include <io.h>
  53 #endif
  54
  55 #if (defined(_MSC_VER) && (_MSC_VER <= 1200)) /* we are compiling with Visual Studio 6, that doesn't support the LL suffix*/
  56
  57 /*
  58  * Swap byte ordering of unsigned long long timestamp on a big endian
  59  * machine.
  60  */
  61 #define SWAPLL(ull)  ((ull & 0xff00000000000000) >> 56) | \
  62                       ((ull & 0x00ff000000000000) >> 40) | \
  63                       ((ull & 0x0000ff0000000000) >> 24) | \
  64                       ((ull & 0x000000ff00000000) >> 8)  | \
  65                       ((ull & 0x00000000ff000000) << 8)  | \
  66                       ((ull & 0x0000000000ff0000) << 24) | \
  67                       ((ull & 0x000000000000ff00) << 40) | \
  68                       ((ull & 0x00000000000000ff) << 56)
  69
  70 #else /* A recent Visual studio compiler or not VC */
  71
  72 /*
  73  * Swap byte ordering of unsigned long long timestamp on a big endian
  74  * machine.
  75  */
  76 #define SWAPLL(ull)  ((ull & 0xff00000000000000ULL) >> 56) | \
  77                       ((ull & 0x00ff000000000000ULL) >> 40) | \
  78                       ((ull & 0x0000ff0000000000ULL) >> 24) | \
  79                       ((ull & 0x000000ff00000000ULL) >> 8)  | \
  80                       ((ull & 0x00000000ff000000ULL) << 8)  | \
  81                       ((ull & 0x0000000000ff0000ULL) << 24) | \
  82                       ((ull & 0x000000000000ff00ULL) << 40) | \
  83                       ((ull & 0x00000000000000ffULL) << 56)
  84
  85 #endif /* _MSC_VER */
  86
  87 /*
  88  * Maximum snapshot length.
  89  *
  90  * Somewhat arbitrary, but chosen to be:
  91  *
  92  *    1) big enough for maximum-size Linux loopback packets (65549)
  93  *       and some USB packets captured with USBPcap:
  94  *
  95  *           http://desowin.org/usbpcap/
  96  *
  97  *       (> 131072, < 262144)
  98  *
  99  * and
 100  *
 101  *    2) small enough not to cause attempts to allocate huge amounts of
 102  *       memory; some applications might use the snapshot length in a
 103  *       savefile header to control the size of the buffer they allocate,
 104  *       so a size of, say, 2^31-1 might not work well.
 105  *
 106  * We don't enforce this in pcap_set_snaplen(), but we use it internally.
 107  */
 108 #define MAXIMUM_SNAPLEN         262144
 109
 110 struct pcap_opt {
 111         char    *device;
 112         int     timeout;        /* timeout for buffering */
 113         u_int   buffer_size;
 114         int     promisc;
 115         int     rfmon;          /* monitor mode */
 116         int     immediate;      /* immediate mode - deliver packets as soon as they arrive */
 117         int     nonblock;       /* non-blocking mode - don't wait for packets to be delivered, return "no packets available" */
 118         int     tstamp_type;
 119         int     tstamp_precision;
 120 };
 121
 122 typedef int     (*activate_op_t)(pcap_t *);
 123 typedef int     (*can_set_rfmon_op_t)(pcap_t *);
 124 typedef int     (*read_op_t)(pcap_t *, int cnt, pcap_handler, u_char *);
 125 typedef int     (*inject_op_t)(pcap_t *, const void *, size_t);
 126 typedef int     (*setfilter_op_t)(pcap_t *, struct bpf_program *);
 127 typedef int     (*setdirection_op_t)(pcap_t *, pcap_direction_t);
 128 typedef int     (*set_datalink_op_t)(pcap_t *, int);
 129 typedef int     (*getnonblock_op_t)(pcap_t *);
 130 typedef int     (*setnonblock_op_t)(pcap_t *, int);
 131 typedef int     (*stats_op_t)(pcap_t *, struct pcap_stat *);
 132 #ifdef _WIN32
 133 typedef struct pcap_stat *(*stats_ex_op_t)(pcap_t *, int *);
 134 typedef int     (*setbuff_op_t)(pcap_t *, int);
 135 typedef int     (*setmode_op_t)(pcap_t *, int);
 136 typedef int     (*setmintocopy_op_t)(pcap_t *, int);
 137 typedef HANDLE  (*getevent_op_t)(pcap_t *);
 138 typedef int     (*oid_get_request_op_t)(pcap_t *, bpf_u_int32, void *, size_t *);
 139 typedef int     (*oid_set_request_op_t)(pcap_t *, bpf_u_int32, const void *, size_t *);
 140 typedef u_int   (*sendqueue_transmit_op_t)(pcap_t *, pcap_send_queue *, int);
 141 typedef int     (*setuserbuffer_op_t)(pcap_t *, int);
 142 typedef int     (*live_dump_op_t)(pcap_t *, char *, int, int);
 143 typedef int     (*live_dump_ended_op_t)(pcap_t *, int);
 144 typedef PAirpcapHandle  (*get_airpcap_handle_op_t)(pcap_t *);
 145 #endif
 146 typedef void    (*cleanup_op_t)(pcap_t *);
 147
 148 /*
 149  * We put all the stuff used in the read code path at the beginning,
 150  * to try to keep it together in the same cache line or lines.
 151  */
 152 struct pcap {
 153         /*
 154          * Method to call to read packets on a live capture.
 155          */
 156         read_op_t read_op;
 157
 158         /*
 159          * Method to call to read packets from a savefile.
 160          */
 161         int (*next_packet_op)(pcap_t *, struct pcap_pkthdr *, u_char **);
 162
 163 #ifdef _WIN32
 164         ADAPTER *adapter;
 165 #else
 166         int fd;
 167         int selectable_fd;
 168 #endif /* _WIN32 */
 169
 170         /*
 171          * Read buffer.
 172          */
 173         u_int bufsize;
 174         void *buffer;
 175         u_char *bp;
 176         int cc;
 177
 178         int break_loop;         /* flag set to force break from packet-reading loop */
 179
 180         void *priv;             /* private data for methods */
 181
 182         int swapped;
 183         FILE *rfile;            /* null if live capture, non-null if savefile */
 184         u_int fddipad;
 185         struct pcap *next;      /* list of open pcaps that need stuff cleared on close */
 186
 187         /*
 188          * File version number; meaningful only for a savefile, but we
 189          * keep it here so that apps that (mistakenly) ask for the
 190          * version numbers will get the same zero values that they
 191          * always did.
 192          */
 193         int version_major;
 194         int version_minor;
 195
 196         int snapshot;
 197         int linktype;           /* Network linktype */
 198         int linktype_ext;       /* Extended information stored in the linktype field of a file */
 199         int tzoff;              /* timezone offset */
 200         int offset;             /* offset for proper alignment */
 201         int activated;          /* true if the capture is really started */
 202         int oldstyle;           /* if we're opening with pcap_open_live() */
 203
 204         struct pcap_opt opt;
 205
 206         /*
 207          * Place holder for pcap_next().
 208          */
 209         u_char *pkt;
 210
 211 #ifdef _WIN32
 212         struct pcap_stat stat;          /* used for pcap_stats_ex() */
 213 #endif
 214
 215         /* We're accepting only packets in this direction/these directions. */
 216         pcap_direction_t direction;
 217
 218         /*
 219          * Flags to affect BPF code generation.
 220          */
 221         int bpf_codegen_flags;
 222
 223         /*
 224          * Placeholder for filter code if bpf not in kernel.
 225          */
 226         struct bpf_program fcode;
 227
 228         char errbuf[PCAP_ERRBUF_SIZE + 1];
 229         int dlt_count;
 230         u_int *dlt_list;
 231         int tstamp_type_count;
 232         u_int *tstamp_type_list;
 233         int tstamp_precision_count;
 234         u_int *tstamp_precision_list;
 235
 236         struct pcap_pkthdr pcap_header; /* This is needed for the pcap_next_ex() to work */
 237
 238         /*
 239          * More methods.
 240          */
 241         activate_op_t activate_op;
 242         can_set_rfmon_op_t can_set_rfmon_op;
 243         inject_op_t inject_op;
 244         setfilter_op_t setfilter_op;
 245         setdirection_op_t setdirection_op;
 246         set_datalink_op_t set_datalink_op;
 247         getnonblock_op_t getnonblock_op;
 248         setnonblock_op_t setnonblock_op;
 249         stats_op_t stats_op;
 250
 251         /*
 252          * Routine to use as callback for pcap_next()/pcap_next_ex().
 253          */
 254         pcap_handler oneshot_callback;
 255
 256 #ifdef _WIN32
 257         /*
 258          * These are, at least currently, specific to the Win32 NPF
 259          * driver.
 260          */
 261         stats_ex_op_t stats_ex_op;
 262         setbuff_op_t setbuff_op;
 263         setmode_op_t setmode_op;
 264         setmintocopy_op_t setmintocopy_op;
 265         getevent_op_t getevent_op;
 266         oid_get_request_op_t oid_get_request_op;
 267         oid_set_request_op_t oid_set_request_op;
 268         sendqueue_transmit_op_t sendqueue_transmit_op;
 269         setuserbuffer_op_t setuserbuffer_op;
 270         live_dump_op_t live_dump_op;
 271         live_dump_ended_op_t live_dump_ended_op;
 272         get_airpcap_handle_op_t get_airpcap_handle_op;
 273 #endif
 274         cleanup_op_t cleanup_op;
 275 };
 276
 277 /*
 278  * BPF code generation flags.
 279  */
 280 #define BPF_SPECIAL_VLAN_HANDLING       0x00000001      /* special VLAN handling for Linux */
 281
 282 /*
 283  * This is a timeval as stored in a savefile.
 284  * It has to use the same types everywhere, independent of the actual
 285  * `struct timeval'; `struct timeval' has 32-bit tv_sec values on some
 286  * platforms and 64-bit tv_sec values on other platforms, and writing
 287  * out native `struct timeval' values would mean files could only be
 288  * read on systems with the same tv_sec size as the system on which
 289  * the file was written.
 290  */
 291
 292 struct pcap_timeval {
 293     bpf_int32 tv_sec;           /* seconds */
 294     bpf_int32 tv_usec;          /* microseconds */
 295 };
 296
 297 /*
 298  * This is a `pcap_pkthdr' as actually stored in a savefile.
 299  *
 300  * Do not change the format of this structure, in any way (this includes
 301  * changes that only affect the length of fields in this structure),
 302  * and do not make the time stamp anything other than seconds and
 303  * microseconds (e.g., seconds and nanoseconds).  Instead:
 304  *
 305  *      introduce a new structure for the new format;
 306  *
 307  *      send mail to "tcpdump-workers@lists.tcpdump.org", requesting
 308  *      a new magic number for your new capture file format, and, when
 309  *      you get the new magic number, put it in "savefile.c";
 310  *
 311  *      use that magic number for save files with the changed record
 312  *      header;
 313  *
 314  *      make the code in "savefile.c" capable of reading files with
 315  *      the old record header as well as files with the new record header
 316  *      (using the magic number to determine the header format).
 317  *
 318  * Then supply the changes by forking the branch at
 319  *
 320  *      https://github.com/the-tcpdump-group/libpcap/issues
 321  *
 322  * and issuing a pull request, so that future versions of libpcap and
 323  * programs that use it (such as tcpdump) will be able to read your new
 324  * capture file format.
 325  */
 326
 327 struct pcap_sf_pkthdr {
 328     struct pcap_timeval ts;     /* time stamp */
 329     bpf_u_int32 caplen;         /* length of portion present */
 330     bpf_u_int32 len;            /* length this packet (off wire) */
 331 };
 332
 333 /*
 334  * How a `pcap_pkthdr' is actually stored in savefiles written
 335  * by some patched versions of libpcap (e.g. the ones in Red
 336  * Hat Linux 6.1 and 6.2).
 337  *
 338  * Do not change the format of this structure, in any way (this includes
 339  * changes that only affect the length of fields in this structure).
 340  * Instead, introduce a new structure, as per the above.
 341  */
 342
 343 struct pcap_sf_patched_pkthdr {
 344     struct pcap_timeval ts;     /* time stamp */
 345     bpf_u_int32 caplen;         /* length of portion present */
 346     bpf_u_int32 len;            /* length this packet (off wire) */
 347     int         index;
 348     unsigned short protocol;
 349     unsigned char pkt_type;
 350 };
 351
 352 /*
 353  * User data structure for the one-shot callback used for pcap_next()
 354  * and pcap_next_ex().
 355  */
 356 struct oneshot_userdata {
 357         struct pcap_pkthdr *hdr;
 358         const u_char **pkt;
 359         pcap_t *pd;
 360 };
 361
 362 #ifndef min
 363 #define min(a, b) ((a) > (b) ? (b) : (a))
 364 #endif
 365
 366 int     pcap_offline_read(pcap_t *, int, pcap_handler, u_char *);
 367
 368 #include <stdarg.h>
 369
 370 #include "portability.h"
 371
 372 /*
 373  * Does the packet count argument to a module's read routine say
 374  * "supply packets until you run out of packets"?
 375  */
 376 #define PACKET_COUNT_IS_UNLIMITED(count)        ((count) <= 0)
 377
 378 /*
 379  * Routines that most pcap implementations can use for non-blocking mode.
 380  */
 381 #if !defined(_WIN32) && !defined(MSDOS)
 382 int     pcap_getnonblock_fd(pcap_t *);
 383 int     pcap_setnonblock_fd(pcap_t *p, int);
 384 #endif
 385
 386 /*
 387  * Internal interfaces for "pcap_create()".
 388  *
 389  * "pcap_create_interface()" is the routine to do a pcap_create on
 390  * a regular network interface.  There are multiple implementations
 391  * of this, one for each platform type (Linux, BPF, DLPI, etc.),
 392  * with the one used chosen by the configure script.
 393  *
 394  * "pcap_create_common()" allocates and fills in a pcap_t, for use
 395  * by pcap_create routines.
 396  */
 397 pcap_t  *pcap_create_interface(const char *, char *);
 398 pcap_t  *pcap_create_common(char *, size_t);
 399 int     pcap_do_addexit(pcap_t *);
 400 void    pcap_add_to_pcaps_to_close(pcap_t *);
 401 void    pcap_remove_from_pcaps_to_close(pcap_t *);
 402 void    pcap_cleanup_live_common(pcap_t *);
 403 int     pcap_check_activated(pcap_t *);
 404
 405 /*
 406  * Internal interfaces for "pcap_findalldevs()".
 407  *
 408  * A pcap_if_list_t * is a reference to a list of devices.
 409  *
 410  * "pcap_platform_finddevs()" is the platform-dependent routine to
 411  * find local network interfaces.
 412  *
 413  * "pcap_findalldevs_interfaces()" is a helper to find those interfaces
 414  * using the "standard" mechanisms (SIOCGIFCONF, "getifaddrs()", etc.).
 415  *
 416  * "add_dev()" adds an entry to a pcap_if_list_t.
 417  *
 418  * "find_dev()" tries to find a device, by name, in a pcap_if_list_t.
 419  *
 420  * "find_or_add_dev()" checks whether a device is already in a pcap_if_list_t
 421  * and, if not, adds an entry for it.
 422  */
 423 struct pcap_if_list;
 424 typedef struct pcap_if_list pcap_if_list_t;
 425 int     pcap_platform_finddevs(pcap_if_list_t *, char *);
 426 #if !defined(_WIN32) && !defined(MSDOS)
 427 int     pcap_findalldevs_interfaces(pcap_if_list_t *, char *,
 428             int (*)(const char *));
 429 #endif
 430 pcap_if_t *find_or_add_dev(pcap_if_list_t *, const char *, bpf_u_int32,
 431             const char *, char *);
 432 pcap_if_t *find_dev(pcap_if_list_t *, const char *);
 433 pcap_if_t *add_dev(pcap_if_list_t *, const char *, bpf_u_int32, const char *,
 434             char *);
 435 int     add_addr_to_dev(pcap_if_t *, struct sockaddr *, size_t,
 436             struct sockaddr *, size_t, struct sockaddr *, size_t,
 437             struct sockaddr *dstaddr, size_t, char *errbuf);
 438 #ifndef _WIN32
 439 pcap_if_t *find_or_add_if(pcap_if_list_t *, const char *, bpf_u_int32,
 440             char *);
 441 int     add_addr_to_if(pcap_if_list_t *, const char *, bpf_u_int32,
 442             struct sockaddr *, size_t, struct sockaddr *, size_t,
 443             struct sockaddr *, size_t, struct sockaddr *, size_t, char *);
 444 #endif
 445
 446 /*
 447  * Internal interfaces for "pcap_open_offline()".
 448  *
 449  * "pcap_open_offline_common()" allocates and fills in a pcap_t, for use
 450  * by pcap_open_offline routines.
 451  *
 452  * "sf_cleanup()" closes the file handle associated with a pcap_t, if
 453  * appropriate, and frees all data common to all modules for handling
 454  * savefile types.
 455  */
 456 pcap_t  *pcap_open_offline_common(char *ebuf, size_t size);
 457 void    sf_cleanup(pcap_t *p);
 458
 459 /*
 460  * Internal interfaces for both "pcap_create()" and routines that
 461  * open savefiles.
 462  *
 463  * "pcap_oneshot()" is the standard one-shot callback for "pcap_next()"
 464  * and "pcap_next_ex()".
 465  */
 466 void    pcap_oneshot(u_char *, const struct pcap_pkthdr *, const u_char *);
 467
 468 #ifdef _WIN32
 469 void    pcap_win32_err_to_str(DWORD, char *);
 470 #endif
 471
 472 int     install_bpf_program(pcap_t *, struct bpf_program *);
 473
 474 int     pcap_strcasecmp(const char *, const char *);
 475
 476 #ifdef __cplusplus
 477 }
 478 #endif
 479
 480 #endif