xref: /titanic_41/usr/src/cmd/ssh/libopenbsd-compat/common/bsd-cygwin_util.c (revision 7c478bd95313f5f23a4c958a745db2134aa03244)
1 /*
2  * cygwin_util.c
3  *
4  * Copyright (c) 2000, 2001, Corinna Vinschen <vinschen@cygnus.com>
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  * Created: Sat Sep 02 12:17:00 2000 cv
27  *
28  * This file contains functions for forcing opened file descriptors to
29  * binary mode on Windows systems.
30  */
31 
32 #include "includes.h"
33 
34 RCSID("$Id: bsd-cygwin_util.c,v 1.8 2002/04/15 22:00:52 stevesk Exp $");
35 
36 #pragma ident	"%Z%%M%	%I%	%E% SMI"
37 
38 #ifdef HAVE_CYGWIN
39 
40 #include <fcntl.h>
41 #include <stdlib.h>
42 #include <sys/utsname.h>
43 #include <sys/vfs.h>
44 #include <windows.h>
45 #define is_winnt       (GetVersion() < 0x80000000)
46 
47 #define ntsec_on(c)	((c) && strstr((c),"ntsec") && !strstr((c),"nontsec"))
48 #define ntea_on(c)	((c) && strstr((c),"ntea") && !strstr((c),"nontea"))
49 
50 #if defined(open) && open == binary_open
51 # undef open
52 #endif
53 #if defined(pipe) && open == binary_pipe
54 # undef pipe
55 #endif
56 
binary_open(const char * filename,int flags,...)57 int binary_open(const char *filename, int flags, ...)
58 {
59 	va_list ap;
60 	mode_t mode;
61 
62 	va_start(ap, flags);
63 	mode = va_arg(ap, mode_t);
64 	va_end(ap);
65 	return open(filename, flags | O_BINARY, mode);
66 }
67 
binary_pipe(int fd[2])68 int binary_pipe(int fd[2])
69 {
70 	int ret = pipe(fd);
71 
72 	if (!ret) {
73 		setmode (fd[0], O_BINARY);
74 		setmode (fd[1], O_BINARY);
75 	}
76 	return ret;
77 }
78 
check_nt_auth(int pwd_authenticated,struct passwd * pw)79 int check_nt_auth(int pwd_authenticated, struct passwd *pw)
80 {
81 	/*
82 	* The only authentication which is able to change the user
83 	* context on NT systems is the password authentication. So
84 	* we deny all requsts for changing the user context if another
85 	* authentication method is used.
86 	*
87 	* This doesn't apply to Cygwin versions >= 1.3.2 anymore which
88 	* uses the undocumented NtCreateToken() call to create a user
89 	* token if the process has the appropriate privileges and if
90 	* CYGWIN ntsec setting is on.
91 	*/
92 	static int has_create_token = -1;
93 
94 	if (pw == NULL)
95 		return 0;
96 	if (is_winnt) {
97 		if (has_create_token < 0) {
98 			struct utsname uts;
99 		        int major_high = 0, major_low = 0, minor = 0;
100 			char *cygwin = getenv("CYGWIN");
101 
102 			has_create_token = 0;
103 			if (ntsec_on(cygwin) && !uname(&uts)) {
104 				sscanf(uts.release, "%d.%d.%d",
105 				       &major_high, &major_low, &minor);
106 				if (major_high > 1 ||
107 				    (major_high == 1 && (major_low > 3 ||
108 				     (major_low == 3 && minor >= 2))))
109 					has_create_token = 1;
110 			}
111 		}
112 		if (has_create_token < 1 &&
113 		    !pwd_authenticated && geteuid() != pw->pw_uid)
114 			return 0;
115 	}
116 	return 1;
117 }
118 
check_ntsec(const char * filename)119 int check_ntsec(const char *filename)
120 {
121 	char *cygwin;
122 	int allow_ntea = 0;
123 	int allow_ntsec = 0;
124 	struct statfs fsstat;
125 
126 	/* Windows 95/98/ME don't support file system security at all. */
127 	if (!is_winnt)
128 		return 0;
129 
130 	/* Evaluate current CYGWIN settings. */
131 	cygwin = getenv("CYGWIN");
132 	allow_ntea = ntea_on(cygwin);
133 	allow_ntsec = ntsec_on(cygwin);
134 
135 	/*
136 	 * `ntea' is an emulation of POSIX attributes. It doesn't support
137 	 * real file level security as ntsec on NTFS file systems does
138 	 * but it supports FAT filesystems. `ntea' is minimum requirement
139 	 * for security checks.
140 	 */
141 	if (allow_ntea)
142 		return 1;
143 
144 	/*
145 	 * Retrieve file system flags. In Cygwin, file system flags are
146 	 * copied to f_type which has no meaning in Win32 itself.
147 	 */
148 	if (statfs(filename, &fsstat))
149 		return 1;
150 
151 	/*
152 	 * Only file systems supporting ACLs are able to set permissions.
153 	 * `ntsec' is the setting in Cygwin which switches using of NTFS
154 	 * ACLs to support POSIX permissions on files.
155 	 */
156 	if (fsstat.f_type & FS_PERSISTENT_ACLS)
157 		return allow_ntsec;
158 
159 	return 0;
160 }
161 
register_9x_service(void)162 void register_9x_service(void)
163 {
164         HINSTANCE kerneldll;
165         DWORD (*RegisterServiceProcess)(DWORD, DWORD);
166 
167 	/* The service register mechanism in 9x/Me is pretty different from
168 	 * NT/2K/XP.  In NT/2K/XP we're using a special service starter
169 	 * application to register and control sshd as service.  This method
170 	 * doesn't play nicely with 9x/Me.  For that reason we register here
171 	 * as service when running under 9x/Me.  This function is only called
172 	 * by the child sshd when it's going to daemonize.
173 	 */
174 	if (is_winnt)
175 		return;
176 	if (! (kerneldll = LoadLibrary("KERNEL32.DLL")))
177 		return;
178 	if (! (RegisterServiceProcess = (DWORD (*)(DWORD, DWORD))
179 			  GetProcAddress(kerneldll, "RegisterServiceProcess")))
180 		return;
181 	RegisterServiceProcess(0, 1);
182 }
183 
184 #endif /* HAVE_CYGWIN */
185