The Tcpdump Group git mirrors - libpcap/blob - portability.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 portability_h
  35 #define portability_h
  36
  37 /*
  38  * Helpers for portability between Windows and UN*X and between different
  39  * flavors of UN*X.
  40  */
  41
  42 #ifdef __cplusplus
  43 extern "C" {
  44 #endif
  45
  46 #ifndef HAVE_STRLCPY
  47  /*
  48   * Macro that does the same thing as strlcpy().
  49   */
  50  #ifdef _WIN32
  51   /*
  52    * strncpy_s() is supported at least back to Visual
  53    * Studio 2005.
  54    */
  55   #define strlcpy(x, y, z) \
  56         strncpy_s((x), (z), (y), _TRUNCATE)
  57
  58  #else
  59   #define strlcpy(x, y, z) \
  60         (strncpy((x), (y), (z)), \
  61          ((z) <= 0 ? 0 : ((x)[(z) - 1] = '\0')), \
  62          (void) strlen((y)))
  63  #endif
  64 #endif
  65
  66 /*
  67  * For flagging arguments as format strings in MSVC.
  68  */
  69 #if _MSC_VER >= 1400
  70  #include <sal.h>
  71  #if _MSC_VER > 1400
  72   #define FORMAT_STRING(p) _Printf_format_string_ p
  73  #else
  74   #define FORMAT_STRING(p) __format_string p
  75  #endif
  76 #else
  77  #define FORMAT_STRING(p) p
  78 #endif
  79
  80 /*
  81  * On Windows, snprintf(), with that name and with C99 behavior - i.e.,
  82  * guaranteeing that the formatted string is null-terminated - didn't
  83  * appear until Visual Studio 2015.  Prior to that, the C runtime had
  84  * only _snprintf(), which *doesn't* guarantee that the string is
  85  * null-terminated if it is truncated due to the buffer being too
  86  * small.  We therefore can't just define snprintf to be _snprintf
  87  * and define vsnprintf to be _vsnprintf, as we're relying on null-
  88  * termination of strings in all cases.
  89  *
  90  * We also want to allow this to be built with versions of Visual Studio
  91  * prior to VS 2015, so we can't rely on snprintf() being present.
  92  *
  93  * And we want to make sure that, if we support plugins in the future,
  94  * a routine with C99 snprintf() behavior will be available to them.
  95  * We also don't want it to collide with the C library snprintf() if
  96  * there is one.
  97  *
  98  * So we make pcap_snprintf() and pcap_vsnprintf() available, either by
  99  * #defining them to be snprintf or vsnprintf, respectively, or by
 100  * defining our own versions and exporting them.
 101  */
 102 #ifdef HAVE_SNPRINTF
 103 #define pcap_snprintf snprintf
 104 #else
 105 extern int pcap_snprintf(char *, size_t, FORMAT_STRING(const char *), ...);
 106 #endif
 107
 108 #ifdef HAVE_VSNPRINTF
 109 #define pcap_vsnprintf vsnprintf
 110 #else
 111 extern int pcap_vsnprintf(char *, size_t, const char *, va_list ap);
 112 #endif
 113
 114 #ifdef __cplusplus
 115 }
 116 #endif
 117
 118 #endif