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;
}
Bool
BuildExecPath(char *execPath, // OUT: Path to executable for isaexec()
size_t execPathSize) // IN : size of execPath buffer
{
/*
* 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_LIBDIR, execPath, execPathSize)) {
Error("could not obtain LIBDIR\n");
return FALSE;
}
/*
* The wrapper script now emulates the work done by the isaexec command hence
* we will simply call execve(2) below and allow the wrapper to do the rest.
*/
if (strlcat(execPath,
"/bin/vmware-user-wrapper", execPathSize) >= execPathSize) {
Error("could not construct program filename\n");
return FALSE;
}
return TRUE;
}
