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

   1 /* -*- Mode: c; tab-width: 8; indent-tabs-mode: 1; c-basic-offset: 8; -*- */
   2 /*
   3  * Copyright (c) 1993, 1994, 1995, 1996, 1997
   4  *      The Regents of the University of California.  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  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  * 3. All advertising materials mentioning features or use of this software
  15  *    must display the following acknowledgement:
  16  *      This product includes software developed by the Computer Systems
  17  *      Engineering Group at Lawrence Berkeley Laboratory.
  18  * 4. Neither the name of the University nor of the Laboratory may be used
  19  *    to endorse or promote products derived from this software without
  20  *    specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 #ifndef lib_pcap_funcattrs_h
  36 #define lib_pcap_funcattrs_h
  37
  38 #include <pcap/compiler-tests.h>
  39
  40 /*
  41  * Attributes to apply to functions and their arguments, using various
  42  * compiler-specific extensions.
  43  */
  44
  45 /*
  46  * PCAP_API_DEF must be used when defining *data* exported from
  47  * libpcap.  It can be used when defining *functions* exported
  48  * from libpcap, but it doesn't have to be used there.  It
  49  * should not be used in declarations in headers.
  50  *
  51  * PCAP_API must be used when *declaring* data or functions
  52  * exported from libpcap; PCAP_API_DEF won't work on all platforms.
  53  */
  54
  55 #if defined(_WIN32)
  56   /*
  57    * For Windows:
  58    *
  59    *    when building libpcap:
  60    *
  61    *       if we're building it as a DLL, we have to declare API
  62    *       functions with __declspec(dllexport);
  63    *
  64    *       if we're building it as a static library, we don't want
  65    *       to do so.
  66    *
  67    *    when using libpcap:
  68    *
  69    *       if we're using the DLL, calls to its functions are a
  70    *       little more efficient if they're declared with
  71    *       __declspec(dllimport);
  72    *
  73    *       if we're not using the dll, we don't want to declare
  74    *       them that way.
  75    *
  76    * So:
  77    *
  78    *    if pcap_EXPORTS is defined, we define PCAP_API_DEF as
  79    *     __declspec(dllexport);
  80    *
  81    *    if PCAP_DLL is defined, we define PCAP_API_DEF as
  82    *    __declspec(dllimport);
  83    *
  84    *    otherwise, we define PCAP_API_DEF as nothing.
  85    */
  86   #if defined(pcap_EXPORTS)
  87     /*
  88      * We're compiling libpcap as a DLL, so we should export functions
  89      * in our API.
  90      */
  91     #define PCAP_API_DEF        __declspec(dllexport)
  92   #elif defined(PCAP_DLL)
  93     /*
  94      * We're using libpcap as a DLL, so the calls will be a little more
  95      * efficient if we explicitly import the functions.
  96      */
  97     #define PCAP_API_DEF        __declspec(dllimport)
  98   #else
  99     /*
 100      * Either we're building libpcap as a static library, or we're using
 101      * it as a static library, or we don't know for certain that we're
 102      * using it as a dynamic library, so neither import nor export the
 103      * functions explicitly.
 104      */
 105     #define PCAP_API_DEF
 106   #endif
 107 #else /* UN*X */
 108   #ifdef pcap_EXPORTS
 109     /*
 110      * We're compiling libpcap as a (dynamic) shared library, so we should
 111      * export functions in our API.  The compiler might be configured not
 112      * to export functions from a shared library by default, so we might
 113      * have to explicitly mark functions as exported.
 114      */
 115     #if PCAP_IS_AT_LEAST_GNUC_VERSION(3,4) \
 116         || PCAP_IS_AT_LEAST_XL_C_VERSION(12,0)
 117       /*
 118        * GCC 3.4 and later, or some compiler asserting compatibility with
 119        * GCC 3.4 and later, or XL C 13.0 and later, so we have
 120        * __attribute__((visibility()).
 121        */
 122       #define PCAP_API_DEF      __attribute__((visibility("default")))
 123     #elif PCAP_IS_AT_LEAST_SUNC_VERSION(5,5)
 124       /*
 125        * Sun C 5.5 and later, so we have __global.
 126        * (Sun C 5.9 and later also have __attribute__((visibility()),
 127        * but there's no reason to prefer it with Sun C.)
 128        */
 129       #define PCAP_API_DEF      __global
 130     #else
 131       /*
 132        * We don't have anything to say.
 133        */
 134       #define PCAP_API_DEF
 135     #endif
 136   #else
 137     /*
 138      * We're not building libpcap.
 139      */
 140     #define PCAP_API_DEF
 141   #endif
 142 #endif /* _WIN32/UN*X */
 143
 144 #define PCAP_API        PCAP_API_DEF extern
 145
 146 /*
 147  * Definitions to 1) indicate what version of libpcap first had a given
 148  * API and 2) allow upstream providers whose build environments allow
 149  * APIs to be designated as "first available in this release" to do so
 150  * by appropriately defining them.
 151  *
 152  * On macOS, Apple can tweak this to make various APIs "weakly exported
 153  * symbols" to make it easier for software that's distributed in binary
 154  * form and that uses libpcap to run on multiple macOS versions and use
 155  * new APIs when available.  (Yes, such third-party software exists -
 156  * Wireshark provides binary packages for macOS, for example.  tcpdump
 157  * doesn't count, as that's provided by Apple, so each release can
 158  * come with a version compiled to use the APIs present in that release.)
 159  *
 160  * We don't tweak it that way ourselves because, if you're building
 161  * and installing libpcap on macOS yourself, the APIs will be available
 162  * no matter what OS version you're installing it on.
 163  *
 164  * For other platforms, we don't define them, leaving it up to
 165  * others to do so based on their OS versions, if appropriate.
 166  *
 167  * We start with libpcap 0.4, as that was the last LBL release, and
 168  * I've never seen earlier releases.
 169  */
 170 #ifdef __APPLE__
 171 /*
 172  * Apple - insert #include <os/availability.h> here, and replace the two
 173  * #defines below with:
 174  *
 175  *   #define PCAP_API_AVAILABLE API_AVAILABLE
 176  *
 177  * and adjust availabilities as necessary, including adding information
 178  * about operating systems other than macOS.
 179  */
 180 #define PCAP_API_AVAILABLE(...)
 181 #define PCAP_AVAILABLE_0_4      PCAP_API_AVAILABLE(macos(10.0))
 182 #define PCAP_AVAILABLE_0_5      PCAP_API_AVAILABLE(macos(10.0))
 183 #define PCAP_AVAILABLE_0_6      PCAP_API_AVAILABLE(macos(10.1))
 184 #define PCAP_AVAILABLE_0_7      PCAP_API_AVAILABLE(macos(10.4))
 185 #define PCAP_AVAILABLE_0_8      PCAP_API_AVAILABLE(macos(10.4))
 186 #define PCAP_AVAILABLE_0_9      PCAP_API_AVAILABLE(macos(10.5))
 187 #define PCAP_AVAILABLE_1_0      PCAP_API_AVAILABLE(macos(10.6))
 188 /* #define PCAP_AVAILABLE_1_1   no routines added to the API */
 189 #define PCAP_AVAILABLE_1_2      PCAP_API_AVAILABLE(macos(10.9))
 190 /* #define PCAP_AVAILABLE_1_3   no routines added to the API */
 191 /* #define PCAP_AVAILABLE_1_4   no routines added to the API */
 192 #define PCAP_AVAILABLE_1_5      PCAP_API_AVAILABLE(macos(10.10))
 193 /* #define PCAP_AVAILABLE_1_6   no routines added to the API */
 194 #define PCAP_AVAILABLE_1_7      PCAP_API_AVAILABLE(macos(10.12))
 195 #define PCAP_AVAILABLE_1_8      PCAP_API_AVAILABLE(macos(10.13))
 196 #define PCAP_AVAILABLE_1_9      PCAP_API_AVAILABLE(macos(10.13))
 197 /*
 198  * The remote capture APIs are, in 1.9 and 1.10, usually only
 199  * available in the library if the library was built with
 200  * remote capture enabled.
 201  *
 202  * However, macOS Sonoma provides stub versions of those routine,
 203  * which return an error.  This means that we need a separate
 204  * availability indicator macro for those routines, so that
 205  * progras built on macOS Sonoma that attempt to use weak
 206  * importing and availability tests to use those routines
 207  * if they're available will get those routines weakly imported,
 208  * so that if they're run on releases prior to Sonoma, they
 209  * won't get an error from dyld about those routines being
 210  * missing in libpcap.  (If they don't use run-time availability
 211  * tests, they will, instead, get crashes if they call one of
 212  * those routines, as the addresses of those routines will be
 213  * set to 0 by dyld, meaning the program will dereference a
 214  * null pointer and crash when trying to call them.)
 215  *
 216  * (Not that it's useful to use those routines *anyway*, as they're
 217  * stubs that always fail.  The stubs were necessary in order to
 218  * support weak exporting at all.)
 219  */
 220 #define PCAP_AVAILABLE_1_9_REMOTE       PCAP_API_AVAILABLE(macos(14.0))
 221 #define PCAP_AVAILABLE_1_10     PCAP_API_AVAILABLE(macos(12.1))
 222 #define PCAP_AVAILABLE_1_10_REMOTE      PCAP_API_AVAILABLE(macos(14.0))
 223 #define PCAP_AVAILABLE_1_11     /* not released yet, so not in macOS yet */
 224 #else /* __APPLE__ */
 225 #define PCAP_AVAILABLE_0_4
 226 #define PCAP_AVAILABLE_0_5
 227 #define PCAP_AVAILABLE_0_6
 228 #define PCAP_AVAILABLE_0_7
 229 #define PCAP_AVAILABLE_0_8
 230 #define PCAP_AVAILABLE_0_9
 231 #define PCAP_AVAILABLE_1_0
 232 /* #define PCAP_AVAILABLE_1_1   no routines added to the API */
 233 #define PCAP_AVAILABLE_1_2
 234 /* #define PCAP_AVAILABLE_1_3   no routines added to the API */
 235 /* #define PCAP_AVAILABLE_1_4   no routines added to the API */
 236 #define PCAP_AVAILABLE_1_5
 237 /* #define PCAP_AVAILABLE_1_6   no routines added to the API */
 238 #define PCAP_AVAILABLE_1_7
 239 #define PCAP_AVAILABLE_1_8
 240 #define PCAP_AVAILABLE_1_9
 241 #define PCAP_AVAILABLE_1_9_REMOTE
 242 #define PCAP_AVAILABLE_1_10
 243 #define PCAP_AVAILABLE_1_10_REMOTE
 244 #define PCAP_AVAILABLE_1_11
 245 #endif /* __APPLE__ */
 246
 247 /*
 248  * PCAP_NORETURN, before a function declaration, means "this function
 249  * never returns".  (It must go before the function declaration, e.g.
 250  * "extern PCAP_NORETURN func(...)" rather than after the function
 251  * declaration, as the MSVC version has to go before the declaration.)
 252  *
 253  * PCAP_NORETURN_DEF, before a function *definition*, means "this
 254  * function never returns"; it would be used only for static functions
 255  * that are defined before any use, and thus have no declaration.
 256  * (MSVC doesn't support that; I guess the "decl" in "__declspec"
 257  * means "declaration", and __declspec doesn't work with definitions.)
 258  */
 259 #if __has_attribute(noreturn) \
 260     || PCAP_IS_AT_LEAST_GNUC_VERSION(2,5) \
 261     || PCAP_IS_AT_LEAST_SUNC_VERSION(5,9) \
 262     || PCAP_IS_AT_LEAST_XL_C_VERSION(7,0) \
 263     || PCAP_IS_AT_LEAST_HP_C_CXX_VERSION(6,10) \
 264     || __TINYC__
 265   /*
 266    * Compiler with support for __attribute((noreturn)), or GCC 2.5 and
 267    * later, or some compiler asserting compatibility with GCC 2.5 and
 268    * later, or Solaris Studio 12 (Sun C 5.9) and later, or IBM XL C 7.0
 269    * and later (do any earlier versions of XL C support this?), or HP aCC
 270    * A.06.10 and later, or current TinyCC.
 271    */
 272   #define PCAP_NORETURN __attribute((noreturn))
 273   #define PCAP_NORETURN_DEF __attribute((noreturn))
 274 #elif defined(_MSC_VER)
 275   /*
 276    * MSVC.
 277    */
 278   #define PCAP_NORETURN __declspec(noreturn)
 279   #define PCAP_NORETURN_DEF
 280 #else
 281   #define PCAP_NORETURN
 282   #define PCAP_NORETURN_DEF
 283 #endif
 284
 285 /*
 286  * PCAP_PRINTFLIKE(x,y), after a function declaration, means "this function
 287  * does printf-style formatting, with the xth argument being the format
 288  * string and the yth argument being the first argument for the format
 289  * string".
 290  */
 291 #if __has_attribute(__format__) \
 292     || PCAP_IS_AT_LEAST_GNUC_VERSION(2,3) \
 293     || PCAP_IS_AT_LEAST_XL_C_VERSION(7,0) \
 294     || PCAP_IS_AT_LEAST_HP_C_CXX_VERSION(6,10)
 295   /*
 296    * Compiler with support for it, or GCC 2.3 and later, or some compiler
 297    * asserting compatibility with GCC 2.3 and later, or IBM XL C 7.0
 298    * and later (do any earlier versions of XL C support this?),
 299    * or HP aCC A.06.10 and later.
 300    */
 301   #define PCAP_PRINTFLIKE(x,y) __attribute__((__format__(__printf__,x,y)))
 302 #else
 303   #define PCAP_PRINTFLIKE(x,y)
 304 #endif
 305
 306 /*
 307  * PCAP_NONNULL(...), after a function declaration, means "the arguments
 308  * whose ordinal numbers are listed are pointer arguments that must be
 309  * non-null".
 310  */
 311 #if __has_attribute(nonnull) \
 312     || PCAP_IS_AT_LEAST_GNUC_VERSION(3,3) \
 313     || PCAP_IS_AT_LEAST_XL_C_VERSION(10,1)
 314   /*
 315    * Compiler with support for it, or GCC 3.3 and later, or some compiler
 316    * asserting compatibility with GCC 3.3 and later, or IBM XL C 10.1
 317    * and later (do any earlier versions of XL C support this?).
 318    */
 319   #define PCAP_NONNULL(...) __attribute__((nonnull(__VA_ARGS__)))
 320 #else
 321   #define PCAP_NONNULL(...)
 322 #endif
 323
 324 /*
 325  * PCAP_WARN_UNUSED_RESULT(...), after a function declaration, means
 326  * "the return value of this function should always be used".
 327  */
 328 #if __has_attribute(warn_unused_result) \
 329     || PCAP_IS_AT_LEAST_GNUC_VERSION(3,4) \
 330     || PCAP_IS_AT_LEAST_XL_C_VERSION(10,1)
 331   /*
 332    * Compiler with support for it, or GCC 3.4 and later, or some compiler
 333    * asserting compatibility with GCC 3.4 and later, or IBM XL C 10.1
 334    * and later (do any earlier versions of XL C support this?).
 335    */
 336   #define PCAP_WARN_UNUSED_RESULT __attribute__((warn_unused_result))
 337 #else
 338   #define PCAP_WARN_UNUSED_RESULT
 339 #endif
 340
 341 /*
 342  * PCAP_DEPRECATED(func, msg), after a function declaration, marks the
 343  * function as deprecated.
 344  *
 345  * The argument is a string giving the warning message to use if the
 346  * compiler supports that.
 347  */
 348 #if __has_attribute(deprecated) \
 349     || PCAP_IS_AT_LEAST_GNUC_VERSION(4,5) \
 350     || PCAP_IS_AT_LEAST_SUNC_VERSION(5,13)
 351   /*
 352    * Compiler that supports __has_attribute and __attribute__((deprecated)),
 353    * or GCC 4.5 and later, or Sun/Oracle C 12.4 (Sun C 5.13) and later.
 354    *
 355    * Those support __attribute__((deprecated(msg))) (we assume, perhaps
 356    * incorrectly, that anything that supports __has_attribute() is
 357    * recent enough to support __attribute__((deprecated(msg)))).
 358    */
 359   #define PCAP_DEPRECATED(msg)  __attribute__((deprecated(msg)))
 360 #elif PCAP_IS_AT_LEAST_GNUC_VERSION(3,1)
 361   /*
 362    * GCC 3.1 through 4.4.
 363    *
 364    * Those support __attribute__((deprecated)) but not
 365    * __attribute__((deprecated(msg))).
 366    */
 367   #define PCAP_DEPRECATED(msg)  __attribute__((deprecated))
 368 #elif defined(_MSC_VER) && !defined(BUILDING_PCAP)
 369   /*
 370    * MSVC, and we're not building libpcap itself; it's VS 2015
 371    * and later, so we have __declspec(deprecated(...)).
 372    *
 373    * If we *are* building libpcap, we don't want this, as it'll warn
 374    * us even if we *define* the function.
 375    */
 376   #define PCAP_DEPRECATED(msg)  _declspec(deprecated(msg))
 377 #else
 378   #define PCAP_DEPRECATED(msg)
 379 #endif
 380
 381 /*
 382  * For flagging arguments as format strings in MSVC.
 383  */
 384 #ifdef _MSC_VER
 385  #include <sal.h>
 386  #define PCAP_FORMAT_STRING(p) _Printf_format_string_ p
 387 #else
 388  #define PCAP_FORMAT_STRING(p) p
 389 #endif
 390
 391 #endif /* lib_pcap_funcattrs_h */