openbsd-compat/bsd-cygwin_util.c

   1 /*
   2  * Copyright (c) 2000, 2001, Corinna Vinschen <vinschen@cygnus.com>
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  14  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  15  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  16  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  17  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  18  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  19  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  20  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  21  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  22  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  23  *
  24  * Created: Sat Sep 02 12:17:00 2000 cv
  25  *
  26  * This file contains functions for forcing opened file descriptors to
  27  * binary mode on Windows systems.
  28  */
  29
  30 #include "includes.h"
  31
  32 RCSID("$Id: bsd-cygwin_util.c,v 1.13 2004/08/30 10:42:08 dtucker Exp $");
  33
  34 #ifdef HAVE_CYGWIN
  35
  36 #include <fcntl.h>
  37 #include <stdlib.h>
  38 #include <sys/utsname.h>
  39 #include <sys/vfs.h>
  40 #include <windows.h>
  41 #include "xmalloc.h"
  42 #define is_winnt       (GetVersion() < 0x80000000)
  43
  44 #define ntsec_on(c)     ((c) && strstr((c),"ntsec") && !strstr((c),"nontsec"))
  45 #define ntsec_off(c)    ((c) && strstr((c),"nontsec"))
  46 #define ntea_on(c)      ((c) && strstr((c),"ntea") && !strstr((c),"nontea"))
  47
  48 #if defined(open) && open == binary_open
  49 # undef open
  50 #endif
  51 #if defined(pipe) && open == binary_pipe
  52 # undef pipe
  53 #endif
  54
  55 int
  56 binary_open(const char *filename, int flags, ...)
  57 {
  58         va_list ap;
  59         mode_t mode;
  60
  61         va_start(ap, flags);
  62         mode = va_arg(ap, mode_t);
  63         va_end(ap);
  64         return (open(filename, flags | O_BINARY, mode));
  65 }
  66
  67 int
  68 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
  79 #define HAS_CREATE_TOKEN 1
  80 #define HAS_NTSEC_BY_DEFAULT 2
  81 #define HAS_CREATE_TOKEN_WO_NTSEC 3
  82
  83 static int
  84 has_capability(int what)
  85 {
  86         static int inited;
  87         static int has_create_token;
  88         static int has_ntsec_by_default;
  89         static int has_create_token_wo_ntsec;
  90
  91         /*
  92          * has_capability() basically calls uname() and checks if
  93          * specific capabilities of Cygwin can be evaluated from that.
  94          * This simplifies the calling functions which only have to ask
  95          * for a capability using has_capability() instead of having
  96          * to figure that out by themselves.
  97          */
  98         if (!inited) {
  99                 struct utsname uts;
 100
 101                 if (!uname(&uts)) {
 102                         int major_high = 0, major_low = 0, minor = 0;
 103                         int api_major_version = 0, api_minor_version = 0;
 104                         char *c;
 105
 106                         sscanf(uts.release, "%d.%d.%d", &major_high,
 107                             &major_low, &minor);
 108                         if ((c = strchr(uts.release, '(')) != NULL) {
 109                                 sscanf(c + 1, "%d.%d", &api_major_version,
 110                                     &api_minor_version);
 111                         }
 112                         if (major_high > 1 ||
 113                             (major_high == 1 && (major_low > 3 ||
 114                             (major_low == 3 && minor >= 2))))
 115                                 has_create_token = 1;
 116                         if (api_major_version > 0 || api_minor_version >= 56)
 117                                 has_ntsec_by_default = 1;
 118                         if (major_high > 1 ||
 119                             (major_high == 1 && major_low >= 5))
 120                                 has_create_token_wo_ntsec = 1;
 121                         inited = 1;
 122                 }
 123         }
 124         switch (what) {
 125         case HAS_CREATE_TOKEN:
 126                 return (has_create_token);
 127         case HAS_NTSEC_BY_DEFAULT:
 128                 return (has_ntsec_by_default);
 129         case HAS_CREATE_TOKEN_WO_NTSEC:
 130                 return (has_create_token_wo_ntsec);
 131         }
 132         return (0);
 133 }
 134
 135 int
 136 check_nt_auth(int pwd_authenticated, struct passwd *pw)
 137 {
 138         /*
 139         * The only authentication which is able to change the user
 140         * context on NT systems is the password authentication. So
 141         * we deny all requsts for changing the user context if another
 142         * authentication method is used.
 143         *
 144         * This doesn't apply to Cygwin versions >= 1.3.2 anymore which
 145         * uses the undocumented NtCreateToken() call to create a user
 146         * token if the process has the appropriate privileges and if
 147         * CYGWIN ntsec setting is on.
 148         */
 149         static int has_create_token = -1;
 150
 151         if (pw == NULL)
 152                 return 0;
 153         if (is_winnt) {
 154                 if (has_create_token < 0) {
 155                         char *cygwin = getenv("CYGWIN");
 156
 157                         has_create_token = 0;
 158                         if (has_capability(HAS_CREATE_TOKEN) &&
 159                             (ntsec_on(cygwin) ||
 160                             (has_capability(HAS_NTSEC_BY_DEFAULT) &&
 161                              !ntsec_off(cygwin)) ||
 162                              has_capability(HAS_CREATE_TOKEN_WO_NTSEC)))
 163                                 has_create_token = 1;
 164                 }
 165                 if (has_create_token < 1 &&
 166                     !pwd_authenticated && geteuid() != pw->pw_uid)
 167                         return (0);
 168         }
 169         return (1);
 170 }
 171
 172 int
 173 check_ntsec(const char *filename)
 174 {
 175         char *cygwin;
 176         int allow_ntea = 0, allow_ntsec = 0;
 177         struct statfs fsstat;
 178
 179         /* Windows 95/98/ME don't support file system security at all. */
 180         if (!is_winnt)
 181                 return (0);
 182
 183         /* Evaluate current CYGWIN settings. */
 184         cygwin = getenv("CYGWIN");
 185         allow_ntea = ntea_on(cygwin);
 186         allow_ntsec = ntsec_on(cygwin) ||
 187             (has_capability(HAS_NTSEC_BY_DEFAULT) && !ntsec_off(cygwin));
 188
 189         /*
 190          * `ntea' is an emulation of POSIX attributes. It doesn't support
 191          * real file level security as ntsec on NTFS file systems does
 192          * but it supports FAT filesystems. `ntea' is minimum requirement
 193          * for security checks.
 194          */
 195         if (allow_ntea)
 196                 return (1);
 197
 198         /*
 199          * Retrieve file system flags. In Cygwin, file system flags are
 200          * copied to f_type which has no meaning in Win32 itself.
 201          */
 202         if (statfs(filename, &fsstat))
 203                 return (1);
 204
 205         /*
 206          * Only file systems supporting ACLs are able to set permissions.
 207          * `ntsec' is the setting in Cygwin which switches using of NTFS
 208          * ACLs to support POSIX permissions on files.
 209          */
 210         if (fsstat.f_type & FS_PERSISTENT_ACLS)
 211                 return (allow_ntsec);
 212
 213         return (0);
 214 }
 215
 216 void
 217 register_9x_service(void)
 218 {
 219         HINSTANCE kerneldll;
 220         DWORD (*RegisterServiceProcess)(DWORD, DWORD);
 221
 222         /* The service register mechanism in 9x/Me is pretty different from
 223          * NT/2K/XP.  In NT/2K/XP we're using a special service starter
 224          * application to register and control sshd as service.  This method
 225          * doesn't play nicely with 9x/Me.  For that reason we register here
 226          * as service when running under 9x/Me.  This function is only called
 227          * by the child sshd when it's going to daemonize.
 228          */
 229         if (is_winnt)
 230                 return;
 231         if (!(kerneldll = LoadLibrary("KERNEL32.DLL")))
 232                 return;
 233         if (!(RegisterServiceProcess = (DWORD (*)(DWORD, DWORD))
 234                 GetProcAddress(kerneldll, "RegisterServiceProcess")))
 235                 return;
 236         RegisterServiceProcess(0, 1);
 237 }
 238
 239 #define NL(x) x, (sizeof (x) - 1)
 240 #define WENV_SIZ (sizeof (wenv_arr) / sizeof (wenv_arr[0]))
 241
 242 static struct wenv {
 243         const char *name;
 244         size_t namelen;
 245 } wenv_arr[] = {
 246         { NL("ALLUSERSPROFILE=") },
 247         { NL("COMMONPROGRAMFILES=") },
 248         { NL("COMPUTERNAME=") },
 249         { NL("COMSPEC=") },
 250         { NL("NUMBER_OF_PROCESSORS=") },
 251         { NL("OS=") },
 252         { NL("PATH=") },
 253         { NL("PATHEXT=") },
 254         { NL("PROCESSOR_ARCHITECTURE=") },
 255         { NL("PROCESSOR_IDENTIFIER=") },
 256         { NL("PROCESSOR_LEVEL=") },
 257         { NL("PROCESSOR_REVISION=") },
 258         { NL("PROGRAMFILES=") },
 259         { NL("SYSTEMDRIVE=") },
 260         { NL("SYSTEMROOT=") },
 261         { NL("TMP=") },
 262         { NL("TEMP=") },
 263         { NL("WINDIR=") },
 264 };
 265
 266 char **
 267 fetch_windows_environment(void)
 268 {
 269         char **e, **p;
 270         int i, idx = 0;
 271
 272         p = xmalloc(WENV_SIZ * sizeof(char *));
 273         for (e = environ; *e != NULL; ++e) {
 274                 for (i = 0; i < WENV_SIZ; ++i) {
 275                         if (!strncmp(*e, wenv_arr[i].name, wenv_arr[i].namelen))
 276                                 p[idx++] = *e;
 277                 }
 278         }
 279         p[idx] = NULL;
 280         return p;
 281 }
 282
 283 void
 284 free_windows_environment(char **p)
 285 {
 286         xfree(p);
 287 }
 288
 289 #endif /* HAVE_CYGWIN */