/**
* @internal
*
* @brief Check if we talk to the priviliged pipe which should be owned by root.
*
* This checks if we have uid_wrapper running and if this is the case it will
* allow to connect to the winbind privileged pipe even it is not owned by root.
*
* @param[in] uid The uid to check if we can safely talk to the pipe.
*
* @return If we have access it returns true, else false.
*/
static bool winbind_privileged_pipe_is_root(uid_t uid)
{
if (uid == 0) {
return true;
}
if (uid_wrapper_enabled()) {
return true;
}
return false;
}
/* Checks whether the peer in a socket has the expected @uid and @gid.
* Returns zero on success.
*/
int check_upeer_id(const char *mod, int debug, int cfd, uid_t uid, uid_t gid, uid_t *ruid, pid_t *pid)
{
int e, ret;
#if defined(SO_PEERCRED) && defined(HAVE_STRUCT_UCRED)
struct ucred cr;
socklen_t cr_len;
/* This check is superfluous in Linux and mostly for debugging
* purposes. The socket permissions set with umask should
* be sufficient already for access control, but not all
* UNIXes support that. */
cr_len = sizeof(cr);
ret = getsockopt(cfd, SOL_SOCKET, SO_PEERCRED, &cr, &cr_len);
if (ret == -1) {
e = errno;
syslog(LOG_ERR, "%s: getsockopt SO_PEERCRED error: %s",
mod, strerror(e));
return -1;
}
if (debug >= 3)
syslog(LOG_DEBUG,
"%s: received request from pid %u and uid %u",
mod, (unsigned)cr.pid, (unsigned)cr.uid);
if (ruid)
*ruid = cr.uid;
if (pid)
*pid = cr.pid;
/* To enable testing we use uid_wrapper. That unfortunately cannot handle
* this credential checking, so we disable credential checking when using it */
if (uid_wrapper_enabled() != 0) return 0;
if (cr.uid != 0 && (cr.uid != uid || cr.gid != gid)) {
syslog(LOG_ERR,
"%s: received unauthorized request from pid %u and uid %u",
mod, (unsigned)cr.pid, (unsigned)cr.uid);
return -1;
}
#elif defined(HAVE_GETPEEREID)
uid_t euid;
gid_t egid;
ret = getpeereid(cfd, &euid, &egid);
if (ret == -1) {
e = errno;
syslog(LOG_DEBUG, "%s: getpeereid error: %s",
mod, strerror(e));
return -1;
}
if (ruid)
*ruid = euid;
if (pid)
*pid = 0;
if (debug >= 3)
syslog(LOG_DEBUG,
"%s: received request from a processes with uid %u",
mod, (unsigned)euid);
/* see above */
if (uid_wrapper_enabled() != 0) return 0;
if (euid != 0 && (euid != uid || egid != gid)) {
syslog(LOG_ERR,
"%s: received unauthorized request from a process with uid %u",
mod, (unsigned)euid);
return -1;
}
#else
#error "Unsupported UNIX variant"
#endif
return 0;
}
