openbsd-compat/xmmap.c

   1 /*
   2  * Copyright (c) 2002 Tim Rice.  All rights reserved.
   3  * MAP_FAILED code by Solar Designer.
   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  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  17  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 /* $Id: xmmap.c,v 1.15 2009/02/16 04:21:40 djm Exp $ */
  27
  28 #include "includes.h"
  29
  30 #include <sys/types.h>
  31 #ifdef HAVE_SYS_MMAN_H
  32 #include <sys/mman.h>
  33 #endif
  34 #include <sys/stat.h>
  35
  36 #ifdef HAVE_FCNTL_H
  37 # include <fcntl.h>
  38 #endif
  39 #include <errno.h>
  40 #include <stdarg.h>
  41 #include <stdlib.h>
  42 #include <string.h>
  43 #include <unistd.h>
  44
  45 #include "log.h"
  46
  47 void *
  48 xmmap(size_t size)
  49 {
  50 #ifdef HAVE_MMAP
  51         void *address;
  52
  53 # ifdef MAP_ANON
  54         address = mmap(NULL, size, PROT_WRITE|PROT_READ, MAP_ANON|MAP_SHARED,
  55             -1, (off_t)0);
  56 # else
  57         address = mmap(NULL, size, PROT_WRITE|PROT_READ, MAP_SHARED,
  58             open("/dev/zero", O_RDWR), (off_t)0);
  59 # endif
  60
  61 #define MM_SWAP_TEMPLATE "/var/run/sshd.mm.XXXXXXXX"
  62         if (address == (void *)MAP_FAILED) {
  63                 char tmpname[sizeof(MM_SWAP_TEMPLATE)] = MM_SWAP_TEMPLATE;
  64                 int tmpfd;
  65                 mode_t old_umask;
  66
  67                 old_umask = umask(0177);
  68                 tmpfd = mkstemp(tmpname);
  69                 umask(old_umask);
  70                 if (tmpfd == -1)
  71                         fatal("mkstemp(\"%s\"): %s",
  72                             MM_SWAP_TEMPLATE, strerror(errno));
  73                 unlink(tmpname);
  74                 if (ftruncate(tmpfd, size) != 0)
  75                         fatal("%s: ftruncate: %s", __func__, strerror(errno));
  76                 address = mmap(NULL, size, PROT_WRITE|PROT_READ, MAP_SHARED,
  77                     tmpfd, (off_t)0);
  78                 close(tmpfd);
  79         }
  80
  81         return (address);
  82 #else
  83         fatal("%s: UsePrivilegeSeparation=yes and Compression=yes not supported",
  84             __func__);
  85 #endif /* HAVE_MMAP */
  86
  87 }
  88