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/*********************************************************
* Copyright (C) 2007 VMware, Inc. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation version 2.1 and no later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the Lesser GNU General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
*********************************************************/
/*
* wrapper.c --
*
* Platform specific code for the VMware User Agent setuid wrapper.
*/
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "vmware.h"
#include "wrapper.h"
/*
* Global functions
*/
#ifdef USES_LOCATIONS_DB
/*
*-----------------------------------------------------------------------------
*
* BuildExecPath --
*
* Determine & return path of vmware-user for use by execve(2).
*
* Results:
* TRUE on success, FALSE otherwise
*
* Side effects:
* None.
*
*-----------------------------------------------------------------------------
*/
Bool
BuildExecPath(char *execPath, // OUT: Buffer to store executable's path
size_t execPathSize) // IN : size of execPath buffer
{
char tmpPath[MAXPATHLEN];
int execLen;
/*
* The locations database is the only path that's fixed, and it contains the
* paths to all the other paths selected during Tools configuration. The
* locations database file is only writable by root, so we can trust it.
*/
if (!QueryLocationsDB(LOCATIONS_PATH, QUERY_BINDIR, tmpPath, sizeof tmpPath)) {
Error("could not obtain BINDIR\n");
return FALSE;
}
if (strlcat(tmpPath,
"/vmware-user-wrapper", sizeof tmpPath) >= sizeof tmpPath) {
Error("could not construct program filename\n");
return FALSE;
}
/*
* From readlink(2), "The readlink() system call does not append a NUL
* character to buf." (NB: This breaks if user ever replaces the symlink
* with the target.)
*/
if ((execLen = readlink(tmpPath, execPath, execPathSize - 1)) == -1) {
Error("could not resolve symlink: %s\n", strerror(errno));
return FALSE;
}
execPath[execLen] = '\0';
/*
* Now make sure that the target is actually part of our "trusted"
* directory. (Check that execPath has LIBDIR as a prefix and does
* not contain "..".)
*/
if (!QueryLocationsDB(LOCATIONS_PATH, QUERY_LIBDIR, tmpPath,
sizeof tmpPath)) {
Error("could not obtain LIBDIR\n");
return FALSE;
}
if ((strncmp(execPath, tmpPath, strlen(tmpPath)) != 0) ||
(strstr(execPath, "..") != NULL)) {
Error("vmware-user path untrusted\n");
return FALSE;
}
return TRUE;
}
#endif // ifdef USES_LOCATIONS_DB
/*
*----------------------------------------------------------------------------
*
* CompatExec --
*
* Simple platform-dependent execve() wrapper.
*
* Results:
* False.
*
* Side effects:
* This function may not return.
*
*----------------------------------------------------------------------------
*/
Bool
CompatExec(const char *path, char * const argv[], char * const envp[])
{
execve(path, argv, envp);
return FALSE;
}
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