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   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 WIN32
  44 #include <Packet32.h>
  45 extern CRITICAL_SECTION g_PcapCompileCriticalSection;
  46 #endif /* WIN32 */
  47
  48 #ifdef MSDOS
  49 #include <fcntl.h>
  50 #include <io.h>
  51 #endif
  52
  53 #if (defined(_MSC_VER) && (_MSC_VER <= 1200)) /* we are compiling with Visual Studio 6, that doesn't support the LL suffix*/
  54
  55 /*
  56  * Swap byte ordering of unsigned long long timestamp on a big endian
  57  * machine.
  58  */
  59 #define SWAPLL(ull)  ((ull & 0xff00000000000000) >> 56) | \
  60                       ((ull & 0x00ff000000000000) >> 40) | \
  61                       ((ull & 0x0000ff0000000000) >> 24) | \
  62                       ((ull & 0x000000ff00000000) >> 8)  | \
  63                       ((ull & 0x00000000ff000000) << 8)  | \
  64                       ((ull & 0x0000000000ff0000) << 24) | \
  65                       ((ull & 0x000000000000ff00) << 40) | \
  66                       ((ull & 0x00000000000000ff) << 56)
  67
  68 #else /* A recent Visual studio compiler or not VC */
  69
  70 /*
  71  * Swap byte ordering of unsigned long long timestamp on a big endian
  72  * machine.
  73  */
  74 #define SWAPLL(ull)  ((ull & 0xff00000000000000LL) >> 56) | \
  75                       ((ull & 0x00ff000000000000LL) >> 40) | \
  76                       ((ull & 0x0000ff0000000000LL) >> 24) | \
  77                       ((ull & 0x000000ff00000000LL) >> 8)  | \
  78                       ((ull & 0x00000000ff000000LL) << 8)  | \
  79                       ((ull & 0x0000000000ff0000LL) << 24) | \
  80                       ((ull & 0x000000000000ff00LL) << 40) | \
  81                       ((ull & 0x00000000000000ffLL) << 56)
  82
  83 #endif /* _MSC_VER */
  84
  85 /*
  86  * Maximum snapshot length.
  87  *
  88  * Somewhat arbitrary, but chosen to be:
  89  *
  90  *    1) big enough for maximum-size Linux loopback packets (65549)
  91  *       and some USB packets captured with USBPcap:
  92  *
  93  *           http://desowin.org/usbpcap/
  94  *
  95  *       (> 131072, < 262144)
  96  *
  97  * and
  98  *
  99  *    2) small enough not to cause attempts to allocate huge amounts of
 100  *       memory; some applications might use the snapshot length in a
 101  *       savefile header to control the size of the buffer they allocate,
 102  *       so a size of, say, 2^31-1 might not work well.
 103  *
 104  * We don't enforce this in pcap_set_snaplen(), but we use it internally.
 105  */
 106 #define MAXIMUM_SNAPLEN         262144
 107
 108 struct pcap_opt {
 109         char    *source;
 110         int     timeout;        /* timeout for buffering */
 111         int     buffer_size;
 112         int     promisc;
 113         int     rfmon;          /* monitor mode */
 114         int     immediate;      /* immediate mode - deliver packets as soon as they arrive */
 115         int     tstamp_type;
 116         int     tstamp_precision;
 117 };
 118
 119 typedef int     (*activate_op_t)(pcap_t *);
 120 typedef int     (*can_set_rfmon_op_t)(pcap_t *);
 121 typedef int     (*read_op_t)(pcap_t *, int cnt, pcap_handler, u_char *);
 122 typedef int     (*inject_op_t)(pcap_t *, const void *, size_t);
 123 typedef int     (*setfilter_op_t)(pcap_t *, struct bpf_program *);
 124 typedef int     (*setdirection_op_t)(pcap_t *, pcap_direction_t);
 125 typedef int     (*set_datalink_op_t)(pcap_t *, int);
 126 typedef int     (*getnonblock_op_t)(pcap_t *, char *);
 127 typedef int     (*setnonblock_op_t)(pcap_t *, int, char *);
 128 typedef int     (*stats_op_t)(pcap_t *, struct pcap_stat *);
 129 #ifdef WIN32
 130 typedef int     (*setbuff_op_t)(pcap_t *, int);
 131 typedef int     (*setmode_op_t)(pcap_t *, int);
 132 typedef int     (*setmintocopy_op_t)(pcap_t *, int);
 133 typedef Adapter *(*getadapter_op_t)(pcap_t *);
 134 #endif
 135 typedef void    (*cleanup_op_t)(pcap_t *);
 136
 137 /*
 138  * We put all the stuff used in the read code path at the beginning,
 139  * to try to keep it together in the same cache line or lines.
 140  */
 141 struct pcap {
 142         /*
 143          * Method to call to read packets on a live capture.
 144          */
 145         read_op_t read_op;
 146
 147         /*
 148          * Method to call to read to read packets from a savefile.
 149          */
 150         int (*next_packet_op)(pcap_t *, struct pcap_pkthdr *, u_char **);
 151
 152 #ifdef WIN32
 153         ADAPTER *adapter;
 154         LPPACKET Packet;
 155         int nonblock;
 156 #else
 157         int fd;
 158         int selectable_fd;
 159 #endif /* WIN32 */
 160
 161         /*
 162          * Read buffer.
 163          */
 164         int bufsize;
 165         u_char *buffer;
 166         u_char *bp;
 167         int cc;
 168
 169         int break_loop;         /* flag set to force break from packet-reading loop */
 170
 171         void *priv;             /* private data for methods */
 172
 173         int swapped;
 174         FILE *rfile;            /* null if live capture, non-null if savefile */
 175         int fddipad;
 176         struct pcap *next;      /* list of open pcaps that need stuff cleared on close */
 177
 178         /*
 179          * File version number; meaningful only for a savefile, but we
 180          * keep it here so that apps that (mistakenly) ask for the
 181          * version numbers will get the same zero values that they
 182          * always did.
 183          */
 184         int version_major;
 185         int version_minor;
 186
 187         int snapshot;
 188         int linktype;           /* Network linktype */
 189         int linktype_ext;       /* Extended information stored in the linktype field of a file */
 190         int tzoff;              /* timezone offset */
 191         int offset;             /* offset for proper alignment */
 192         int activated;          /* true if the capture is really started */
 193         int oldstyle;           /* if we're opening with pcap_open_live() */
 194
 195         struct pcap_opt opt;
 196
 197         /*
 198          * Place holder for pcap_next().
 199          */
 200         u_char *pkt;
 201
 202         /* We're accepting only packets in this direction/these directions. */
 203         pcap_direction_t direction;
 204
 205         /*
 206          * Flags to affect BPF code generation.
 207          */
 208         int bpf_codegen_flags;
 209
 210         /*
 211          * Placeholder for filter code if bpf not in kernel.
 212          */
 213         struct bpf_program fcode;
 214
 215         char errbuf[PCAP_ERRBUF_SIZE + 1];
 216         int dlt_count;
 217         u_int *dlt_list;
 218         int tstamp_type_count;
 219         u_int *tstamp_type_list;
 220         int tstamp_precision_count;
 221         u_int *tstamp_precision_list;
 222
 223         struct pcap_pkthdr pcap_header; /* This is needed for the pcap_next_ex() to work */
 224
 225         /*
 226          * More methods.
 227          */
 228         activate_op_t activate_op;
 229         can_set_rfmon_op_t can_set_rfmon_op;
 230         inject_op_t inject_op;
 231         setfilter_op_t setfilter_op;
 232         setdirection_op_t setdirection_op;
 233         set_datalink_op_t set_datalink_op;
 234         getnonblock_op_t getnonblock_op;
 235         setnonblock_op_t setnonblock_op;
 236         stats_op_t stats_op;
 237
 238         /*
 239          * Routine to use as callback for pcap_next()/pcap_next_ex().
 240          */
 241         pcap_handler oneshot_callback;
 242
 243 #ifdef WIN32
 244         /*
 245          * These are, at least currently, specific to the Win32 NPF
 246          * driver.
 247          */
 248         setbuff_op_t setbuff_op;
 249         setmode_op_t setmode_op;
 250         setmintocopy_op_t setmintocopy_op;
 251         getadapter_op_t getadapter_op;
 252 #endif
 253         cleanup_op_t cleanup_op;
 254 };
 255
 256 /*
 257  * BPF code generation flags.
 258  */
 259 #define BPF_SPECIAL_VLAN_HANDLING       0x00000001      /* special VLAN handling for Linux */
 260
 261 /*
 262  * This is a timeval as stored in a savefile.
 263  * It has to use the same types everywhere, independent of the actual
 264  * `struct timeval'; `struct timeval' has 32-bit tv_sec values on some
 265  * platforms and 64-bit tv_sec values on other platforms, and writing
 266  * out native `struct timeval' values would mean files could only be
 267  * read on systems with the same tv_sec size as the system on which
 268  * the file was written.
 269  */
 270
 271 struct pcap_timeval {
 272     bpf_int32 tv_sec;           /* seconds */
 273     bpf_int32 tv_usec;          /* microseconds */
 274 };
 275
 276 /*
 277  * This is a `pcap_pkthdr' as actually stored in a savefile.
 278  *
 279  * Do not change the format of this structure, in any way (this includes
 280  * changes that only affect the length of fields in this structure),
 281  * and do not make the time stamp anything other than seconds and
 282  * microseconds (e.g., seconds and nanoseconds).  Instead:
 283  *
 284  *      introduce a new structure for the new format;
 285  *
 286  *      send mail to "tcpdump-workers@lists.tcpdump.org", requesting
 287  *      a new magic number for your new capture file format, and, when
 288  *      you get the new magic number, put it in "savefile.c";
 289  *
 290  *      use that magic number for save files with the changed record
 291  *      header;
 292  *
 293  *      make the code in "savefile.c" capable of reading files with
 294  *      the old record header as well as files with the new record header
 295  *      (using the magic number to determine the header format).
 296  *
 297  * Then supply the changes by forking the branch at
 298  *
 299  *      https://github.com/the-tcpdump-group/libpcap/issues
 300  *
 301  * and issuing a pull request, so that future versions of libpcap and
 302  * programs that use it (such as tcpdump) will be able to read your new
 303  * capture file format.
 304  */
 305
 306 struct pcap_sf_pkthdr {
 307     struct pcap_timeval ts;     /* time stamp */
 308     bpf_u_int32 caplen;         /* length of portion present */
 309     bpf_u_int32 len;            /* length this packet (off wire) */
 310 };
 311
 312 /*
 313  * How a `pcap_pkthdr' is actually stored in savefiles written
 314  * by some patched versions of libpcap (e.g. the ones in Red
 315  * Hat Linux 6.1 and 6.2).
 316  *
 317  * Do not change the format of this structure, in any way (this includes
 318  * changes that only affect the length of fields in this structure).
 319  * Instead, introduce a new structure, as per the above.
 320  */
 321
 322 struct pcap_sf_patched_pkthdr {
 323     struct pcap_timeval ts;     /* time stamp */
 324     bpf_u_int32 caplen;         /* length of portion present */
 325     bpf_u_int32 len;            /* length this packet (off wire) */
 326     int         index;
 327     unsigned short protocol;
 328     unsigned char pkt_type;
 329 };
 330
 331 /*
 332  * User data structure for the one-shot callback used for pcap_next()
 333  * and pcap_next_ex().
 334  */
 335 struct oneshot_userdata {
 336         struct pcap_pkthdr *hdr;
 337         const u_char **pkt;
 338         pcap_t *pd;
 339 };
 340
 341 int     yylex(void);
 342
 343 #ifndef min
 344 #define min(a, b) ((a) > (b) ? (b) : (a))
 345 #endif
 346
 347 /* XXX should these be in pcap.h? */
 348 int     pcap_offline_read(pcap_t *, int, pcap_handler, u_char *);
 349 int     pcap_read(pcap_t *, int cnt, pcap_handler, u_char *);
 350
 351 #ifndef HAVE_STRLCPY
 352 #define strlcpy(x, y, z) \
 353         (strncpy((x), (y), (z)), \
 354          ((z) <= 0 ? 0 : ((x)[(z) - 1] = '\0')), \
 355          strlen((y)))
 356 #endif
 357
 358 #include <stdarg.h>
 359
 360 #if !defined(HAVE_SNPRINTF)
 361 #define snprintf pcap_snprintf
 362 extern int snprintf (char *, size_t, const char *, ...);
 363 #endif
 364
 365 #if !defined(HAVE_VSNPRINTF)
 366 #define vsnprintf pcap_vsnprintf
 367 extern int vsnprintf (char *, size_t, const char *, va_list ap);
 368 #endif
 369
 370 /*
 371  * Does the packet count argument to a module's read routine say
 372  * "supply packets until you run out of packets"?
 373  */
 374 #define PACKET_COUNT_IS_UNLIMITED(count)        ((count) <= 0)
 375
 376 /*
 377  * Routines that most pcap implementations can use for non-blocking mode.
 378  */
 379 #if !defined(WIN32) && !defined(MSDOS)
 380 int     pcap_getnonblock_fd(pcap_t *, char *);
 381 int     pcap_setnonblock_fd(pcap_t *p, int, char *);
 382 #endif
 383
 384 /*
 385  * Internal interfaces for "pcap_create()".
 386  *
 387  * "pcap_create_interface()" is the routine to do a pcap_create on
 388  * a regular network interface.  There are multiple implementations
 389  * of this, one for each platform type (Linux, BPF, DLPI, etc.),
 390  * with the one used chosen by the configure script.
 391  *
 392  * "pcap_create_common()" allocates and fills in a pcap_t, for use
 393  * by pcap_create routines.
 394  */
 395 pcap_t  *pcap_create_interface(const char *, char *);
 396 pcap_t  *pcap_create_common(const char *, char *, size_t);
 397 int     pcap_do_addexit(pcap_t *);
 398 void    pcap_add_to_pcaps_to_close(pcap_t *);
 399 void    pcap_remove_from_pcaps_to_close(pcap_t *);
 400 void    pcap_cleanup_live_common(pcap_t *);
 401 int     pcap_not_initialized(pcap_t *);
 402 int     pcap_check_activated(pcap_t *);
 403
 404 /*
 405  * Internal interfaces for "pcap_findalldevs()".
 406  *
 407  * "pcap_findalldevs_interfaces()" finds interfaces using the
 408  * "standard" mechanisms (SIOCGIFCONF, "getifaddrs()", etc.).
 409  *
 410  * "pcap_platform_finddevs()" is a platform-dependent routine to
 411  * add devices not found by the "standard" mechanisms.
 412  *
 413  * "pcap_add_if()" adds an interface to the list of interfaces, for
 414  * use by various "find interfaces" routines.
 415  */
 416 int     pcap_findalldevs_interfaces(pcap_if_t **, char *);
 417 int     pcap_platform_finddevs(pcap_if_t **, char *);
 418 int     add_addr_to_iflist(pcap_if_t **, const char *, u_int, struct sockaddr *,
 419             size_t, struct sockaddr *, size_t, struct sockaddr *, size_t,
 420             struct sockaddr *, size_t, char *);
 421 int     add_addr_to_dev(pcap_if_t *, struct sockaddr *, size_t,
 422             struct sockaddr *, size_t, struct sockaddr *, size_t,
 423             struct sockaddr *dstaddr, size_t, char *errbuf);
 424 int     pcap_add_if(pcap_if_t **, const char *, u_int, const char *, char *);
 425 struct sockaddr *dup_sockaddr(struct sockaddr *, size_t);
 426 int     add_or_find_if(pcap_if_t **, pcap_if_t **, const char *, u_int,
 427             const char *, char *);
 428
 429 /*
 430  * Internal interfaces for "pcap_open_offline()".
 431  *
 432  * "pcap_open_offline_common()" allocates and fills in a pcap_t, for use
 433  * by pcap_open_offline routines.
 434  *
 435  * "sf_cleanup()" closes the file handle associated with a pcap_t, if
 436  * appropriate, and frees all data common to all modules for handling
 437  * savefile types.
 438  */
 439 pcap_t  *pcap_open_offline_common(char *ebuf, size_t size);
 440 void    sf_cleanup(pcap_t *p);
 441
 442 /*
 443  * Internal interfaces for both "pcap_create()" and routines that
 444  * open savefiles.
 445  *
 446  * "pcap_oneshot()" is the standard one-shot callback for "pcap_next()"
 447  * and "pcap_next_ex()".
 448  */
 449 void    pcap_oneshot(u_char *, const struct pcap_pkthdr *, const u_char *);
 450
 451 #ifdef WIN32
 452 char    *pcap_win32strerror(void);
 453 #endif
 454
 455 int     install_bpf_program(pcap_t *, struct bpf_program *);
 456
 457 int     pcap_strcasecmp(const char *, const char *);
 458
 459 #ifdef __cplusplus
 460 }
 461 #endif
 462
 463 #endif