contrib/tcpdump/machdep.c

   1 /*
   2  * Copyright (c) 1996, 1997
   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: (1) source code distributions
   7  * retain the above copyright notice and this paragraph in its entirety, (2)
   8  * distributions including binary code include the above copyright notice and
   9  * this paragraph in its entirety in the documentation or other materials
  10  * provided with the distribution, and (3) all advertising materials mentioning
  11  * features or use of this software display the following acknowledgement:
  12  * ``This product includes software developed by the University of California,
  13  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
  14  * the University nor the names of its contributors may be used to endorse
  15  * or promote products derived from this software without specific prior
  16  * written permission.
  17  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
  18  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
  19  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  20  */
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include "config.h"
  24 #endif
  25
  26 /*
  27  * XXX - all we need, on platforms other than DEC OSF/1 (a/k/a Digital UNIX,
  28  * a/k/a Tru64 UNIX), is "size_t", which is a standard C type; what do we
  29  * need to do to get it defined?  This is clearly wrong, as we shouldn't
  30  * have to include UNIX or Windows system header files to get it.
  31  */
  32 #include <netdissect-stdinc.h>
  33
  34 #ifndef HAVE___ATTRIBUTE__
  35 #define __attribute__(x)
  36 #endif /* HAVE___ATTRIBUTE__ */
  37
  38 #ifdef __osf__
  39 #include <sys/sysinfo.h>
  40 #include <sys/proc.h>
  41
  42 #if !defined(HAVE_SNPRINTF)
  43 int snprintf(char *, size_t, const char *, ...)
  44 #ifdef __ATTRIBUTE___FORMAT_OK
  45      __attribute__((format(printf, 3, 4)))
  46 #endif /* __ATTRIBUTE___FORMAT_OK */
  47      ;
  48 #endif /* !defined(HAVE_SNPRINTF) */
  49 #endif /* __osf__ */
  50
  51 #include "machdep.h"
  52
  53 /*
  54  * On platforms where the CPU doesn't support unaligned loads, force
  55  * unaligned accesses to abort with SIGBUS, rather than being fixed
  56  * up (slowly) by the OS kernel; on those platforms, misaligned accesses
  57  * are bugs, and we want tcpdump to crash so that the bugs are reported.
  58  *
  59  * The only OS on which this is necessary is DEC OSF/1^W^WDigital
  60  * UNIX^W^WTru64 UNIX.
  61  */
  62 int
  63 abort_on_misalignment(char *ebuf _U_, size_t ebufsiz _U_)
  64 {
  65 #ifdef __osf__
  66         static int buf[2] = { SSIN_UACPROC, UAC_SIGBUS };
  67
  68         if (setsysinfo(SSI_NVPAIRS, (caddr_t)buf, 1, 0, 0) < 0) {
  69                 (void)snprintf(ebuf, ebufsiz, "setsysinfo: errno %d", errno);
  70                 return (-1);
  71         }
  72 #endif
  73         return (0);
  74 }