xmmap.c revision 137015 
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 1.5 2004/08/14 13:55:38 dtucker Exp $ */
27
28#include "includes.h"
29
30#ifdef HAVE_SYS_MMAN_H
31#include <sys/mman.h>
32#endif
33
34#include "log.h"
35
36void *xmmap(size_t size)
37{
38	void *address;
39
40#ifdef HAVE_MMAP
41# ifdef MAP_ANON
42	address = mmap(NULL, size, PROT_WRITE|PROT_READ, MAP_ANON|MAP_SHARED,
43	    -1, (off_t)0);
44# else
45	address = mmap(NULL, size, PROT_WRITE|PROT_READ, MAP_SHARED,
46	    open("/dev/zero", O_RDWR), (off_t)0);
47# endif
48
49#define MM_SWAP_TEMPLATE "/var/run/sshd.mm.XXXXXXXX"
50	if (address == MAP_FAILED) {
51		char tmpname[sizeof(MM_SWAP_TEMPLATE)] = MM_SWAP_TEMPLATE;
52		int tmpfd;
53		mode_t old_umask;
54
55		old_umask = umask(0177);
56		tmpfd = mkstemp(tmpname);
57		umask(old_umask);
58		if (tmpfd == -1)
59			fatal("mkstemp(\"%s\"): %s",
60			    MM_SWAP_TEMPLATE, strerror(errno));
61		unlink(tmpname);
62		ftruncate(tmpfd, size);
63		address = mmap(NULL, size, PROT_WRITE|PROT_READ, MAP_SHARED,
64		    tmpfd, (off_t)0);
65		close(tmpfd);
66	}
67
68	return (address);
69#else
70	fatal("%s: UsePrivilegeSeparation=yes and Compression=yes not supported",
71	    __func__);
72#endif /* HAVE_MMAP */
73
74}
75
76