reactos/dll/opengl/mesa/src/mesa/main/vsnprintf.c

   1 /*
   2  * Revision 12: http://theos.com/~deraadt/snprintf.c
   3  *
   4  * Copyright (c) 1997 Theo de Raadt
   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  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  */
  26
  27 #ifndef __VMS
  28 # include <sys/param.h>
  29 #endif
  30 #include <sys/types.h>
  31 #include <sys/mman.h>
  32 #include <signal.h>
  33 #include <stdio.h>
  34 #if __STDC__
  35 #include <stdarg.h>
  36 #include <stdlib.h>
  37 #else
  38 #include <varargs.h>
  39 #endif
  40 #include <setjmp.h>
  41 #include <unistd.h>
  42 #include <string.h>
  43
  44 #ifndef roundup
  45 #define roundup(x, y) ((((x)+((y)-1))/(y))*(y))
  46 #endif
  47
  48 #ifdef __sgi
  49 #define size_t ssize_t
  50 #endif
  51
  52 static int pgsize;
  53 static char *curobj;
  54 static int caught;
  55 static sigjmp_buf bail;
  56
  57 #define EXTRABYTES      2       /* XXX: why 2? you don't want to know */
  58
  59 static char *
  60 msetup(str, n)
  61         char *str;
  62         size_t n;
  63 {
  64         char *e;
  65
  66         if (n == 0)
  67                 return NULL;
  68         if (pgsize == 0)
  69                 pgsize = getpagesize();
  70         curobj = (char *)malloc(n + EXTRABYTES + pgsize * 2);
  71         if (curobj == NULL)
  72                 return NULL;
  73         e = curobj + n + EXTRABYTES;
  74         e = (char *)roundup((unsigned long)e, pgsize);
  75         if (mprotect(e, pgsize, PROT_NONE) == -1) {
  76                 free(curobj);
  77                 curobj = NULL;
  78                 return NULL;
  79         }
  80         e = e - n - EXTRABYTES;
  81         *e = '\0';
  82         return (e);
  83 }
  84
  85 static void
  86   mcatch( int a )
  87 {
  88         siglongjmp(bail, 1);
  89 }
  90
  91 static void
  92 mcleanup(str, n, p)
  93         char *str;
  94         size_t n;
  95         char *p;
  96 {
  97         strncpy(str, p, n-1);
  98         str[n-1] = '\0';
  99         if (mprotect((caddr_t)(p + n + EXTRABYTES), pgsize,
 100             PROT_READ|PROT_WRITE|PROT_EXEC) == -1)
 101                 mprotect((caddr_t)(p + n + EXTRABYTES), pgsize,
 102                     PROT_READ|PROT_WRITE);
 103         free(curobj);
 104 }
 105
 106 int
 107 #if __STDC__
 108 vsnprintf(char *str, size_t n, char const *fmt, va_list ap)
 109 #else
 110 vsnprintf(str, n, fmt, ap)
 111         char *str;
 112         size_t n;
 113         char *fmt;
 114         char *ap;
 115 #endif
 116 {
 117         struct sigaction osa, nsa;
 118         char *p;
 119         int ret = n + 1;        /* if we bail, indicated we overflowed */
 120
 121         memset(&nsa, 0, sizeof nsa);
 122         nsa.sa_handler = mcatch;
 123         sigemptyset(&nsa.sa_mask);
 124
 125         p = msetup(str, n);
 126         if (p == NULL) {
 127                 *str = '\0';
 128                 return 0;
 129         }
 130         if (sigsetjmp(bail, 1) == 0) {
 131                 if (sigaction(SIGSEGV, &nsa, &osa) == -1) {
 132                         mcleanup(str, n, p);
 133                         return (0);
 134                 }
 135                 ret = vsprintf(p, fmt, ap);
 136         }
 137         mcleanup(str, n, p);
 138         (void) sigaction(SIGSEGV, &osa, NULL);
 139         return (ret);
 140 }
 141
 142 int
 143 #if __STDC__
 144 snprintf(char *str, size_t n, char const *fmt, ...)
 145 #else
 146 snprintf(str, n, fmt, va_alist)
 147         char *str;
 148         size_t n;
 149         char *fmt;
 150         va_dcl
 151 #endif
 152 {
 153         va_list ap;
 154 #if __STDC__
 155         va_start(ap, fmt);
 156 #else
 157         va_start(ap);
 158 #endif
 159
 160         return (vsnprintf(str, n, fmt, ap));
 161         va_end(ap);
 162 }
 163
 164
 165