forked from lix-project/lix
Drop support for running nix-worker in "slave" mode
AFAIK nobody uses this, setuid binaries are evil, and there is no good reason why people can't just run the daemon.
This commit is contained in:
Eelco Dolstra
parent
7586095504
commit
522ecab9b8
|
|
@ -201,10 +201,8 @@ flag, e.g. <literal>--option gc-keep-outputs false</literal>.</para>
|
|||
under the uid of the Nix process (that is, the uid of the caller
|
||||
if <envar>NIX_REMOTE</envar> is empty, the uid under which the Nix
|
||||
daemon runs if <envar>NIX_REMOTE</envar> is
|
||||
<literal>daemon</literal>, or the uid that owns the setuid
|
||||
<command>nix-worker</command> program if <envar>NIX_REMOTE</envar>
|
||||
is <literal>slave</literal>). Obviously, this should not be used
|
||||
in multi-user settings with untrusted users.</para>
|
||||
<literal>daemon</literal>). Obviously, this should not be used in
|
||||
multi-user settings with untrusted users.</para>
|
||||
|
||||
</listitem>
|
||||
|
||||
|
|
|
|||
|
|
@ -125,8 +125,7 @@ static void initAndRun(int argc, char * * argv)
|
|||
|
||||
/* There is no privacy in the Nix system ;-) At least not for
|
||||
now. In particular, store objects should be readable by
|
||||
everybody. This prevents nasty surprises when using a shared
|
||||
store (with the setuid() hack). */
|
||||
everybody. */
|
||||
umask(0022);
|
||||
|
||||
/* Process the NIX_LOG_TYPE environment variable. */
|
||||
|
|
@ -218,56 +217,6 @@ static void initAndRun(int argc, char * * argv)
|
|||
}
|
||||
|
||||
|
||||
bool setuidMode = false;
|
||||
|
||||
|
||||
static void setuidInit()
|
||||
{
|
||||
/* Don't do anything if this is not a setuid binary. */
|
||||
if (getuid() == geteuid() && getgid() == getegid()) return;
|
||||
|
||||
uid_t nixUid = geteuid();
|
||||
gid_t nixGid = getegid();
|
||||
|
||||
setuidCleanup();
|
||||
|
||||
/* Don't trust the current directory. */
|
||||
if (chdir("/") == -1) abort();
|
||||
|
||||
/* Set the real (and preferably also the save) uid/gid to the
|
||||
effective uid/gid. This matters mostly when we're not using
|
||||
build-users (bad!), since some builders (like Perl) complain
|
||||
when real != effective.
|
||||
|
||||
On systems where setresuid is unavailable, we can't drop the
|
||||
saved uid/gid. This means that we could go back to the
|
||||
original real uid (i.e., the uid of the caller). That's not
|
||||
really a problem, except maybe when we execute a builder and
|
||||
we're not using build-users. In that case, the builder may be
|
||||
able to switch to the uid of the caller and possibly do bad
|
||||
stuff. But note that when not using build-users, the builder
|
||||
could also modify the Nix executables (say, replace them by a
|
||||
Trojan horse), so the problem is already there. */
|
||||
|
||||
#if HAVE_SETRESUID
|
||||
if (setresuid(nixUid, nixUid, nixUid)) abort();
|
||||
if (setresgid(nixGid, nixGid, nixGid)) abort();
|
||||
#elif HAVE_SETREUID
|
||||
/* Note: doesn't set saved uid/gid! */
|
||||
fprintf(stderr, "warning: cannot set saved uid\n");
|
||||
if (setreuid(nixUid, nixUid)) abort();
|
||||
if (setregid(nixGid, nixGid)) abort();
|
||||
#else
|
||||
/* Note: doesn't set real and saved uid/gid! */
|
||||
fprintf(stderr, "warning: cannot set real and saved uids\n");
|
||||
if (setuid(nixUid)) abort();
|
||||
if (setgid(nixGid)) abort();
|
||||
#endif
|
||||
|
||||
setuidMode = true;
|
||||
}
|
||||
|
||||
|
||||
/* Called when the Boehm GC runs out of memory. */
|
||||
static void * oomHandler(size_t requested)
|
||||
{
|
||||
|
|
@ -298,11 +247,6 @@ int main(int argc, char * * argv)
|
|||
|
||||
argvSaved = argv;
|
||||
|
||||
/* If we're setuid, then we need to take some security precautions
|
||||
right away. */
|
||||
if (argc == 0) abort();
|
||||
setuidInit();
|
||||
|
||||
/* Turn on buffering for cerr. */
|
||||
#if HAVE_PUBSETBUF
|
||||
std::cerr.rdbuf()->pubsetbuf(buf, sizeof(buf));
|
||||
|
|
|
|||
|
|
@ -44,9 +44,6 @@ template<class N> N getIntArg(const string & opt,
|
|||
/* Show the manual page for the specified program. */
|
||||
void showManPage(const string & name);
|
||||
|
||||
/* Whether we're running setuid. */
|
||||
extern bool setuidMode;
|
||||
|
||||
extern volatile ::sig_atomic_t blockInt;
|
||||
|
||||
/* Exit code of the program. */
|
||||
|
|
|
|||
|
|
@ -50,16 +50,12 @@ void RemoteStore::openConnection(bool reserveSpace)
|
|||
|
||||
string remoteMode = getEnv("NIX_REMOTE");
|
||||
|
||||
if (remoteMode == "slave")
|
||||
/* Fork off a setuid worker to do the privileged work. */
|
||||
forkSlave();
|
||||
else if (remoteMode == "daemon")
|
||||
if (remoteMode == "daemon")
|
||||
/* Connect to a daemon that does the privileged work for
|
||||
us. */
|
||||
connectToDaemon();
|
||||
else
|
||||
throw Error(format("invalid setting for NIX_REMOTE, `%1%'")
|
||||
% remoteMode);
|
||||
throw Error(format("invalid setting for NIX_REMOTE, `%1%'") % remoteMode);
|
||||
|
||||
from.fd = fdSocket;
|
||||
to.fd = fdSocket;
|
||||
|
|
@ -88,54 +84,6 @@ void RemoteStore::openConnection(bool reserveSpace)
|
|||
}
|
||||
|
||||
|
||||
void RemoteStore::forkSlave()
|
||||
{
|
||||
int sockets[2];
|
||||
if (socketpair(AF_UNIX, SOCK_STREAM, 0, sockets) == -1)
|
||||
throw SysError("cannot create sockets");
|
||||
|
||||
fdSocket = sockets[0];
|
||||
AutoCloseFD fdChild = sockets[1];
|
||||
|
||||
/* Start the worker. */
|
||||
Path worker = getEnv("NIX_WORKER");
|
||||
if (worker == "")
|
||||
worker = settings.nixBinDir + "/nix-worker";
|
||||
|
||||
child = fork();
|
||||
|
||||
switch (child) {
|
||||
|
||||
case -1:
|
||||
throw SysError("unable to fork");
|
||||
|
||||
case 0:
|
||||
try { /* child */
|
||||
|
||||
if (dup2(fdChild, STDOUT_FILENO) == -1)
|
||||
throw SysError("dupping write side");
|
||||
|
||||
if (dup2(fdChild, STDIN_FILENO) == -1)
|
||||
throw SysError("dupping read side");
|
||||
|
||||
close(fdSocket);
|
||||
close(fdChild);
|
||||
|
||||
execlp(worker.c_str(), worker.c_str(), "--slave", NULL);
|
||||
|
||||
throw SysError(format("executing `%1%'") % worker);
|
||||
|
||||
} catch (std::exception & e) {
|
||||
std::cerr << format("child error: %1%\n") % e.what();
|
||||
}
|
||||
quickExit(1);
|
||||
}
|
||||
|
||||
fdChild.close();
|
||||
|
||||
}
|
||||
|
||||
|
||||
void RemoteStore::connectToDaemon()
|
||||
{
|
||||
fdSocket = socket(PF_UNIX, SOCK_STREAM, 0);
|
||||
|
|
|
|||
|
|
@ -893,33 +893,15 @@ static void daemonLoop()
|
|||
|
||||
void run(Strings args)
|
||||
{
|
||||
bool slave = false;
|
||||
bool daemon = false;
|
||||
|
||||
for (Strings::iterator i = args.begin(); i != args.end(); ) {
|
||||
string arg = *i++;
|
||||
if (arg == "--slave") slave = true;
|
||||
if (arg == "--daemon") daemon = true;
|
||||
if (arg == "--daemon") /* ignored for backwards compatibility */;
|
||||
}
|
||||
|
||||
if (slave) {
|
||||
/* This prevents us from receiving signals from the terminal
|
||||
when we're running in setuid mode. */
|
||||
if (setsid() == -1)
|
||||
throw SysError(format("creating a new session"));
|
||||
|
||||
processConnection();
|
||||
}
|
||||
|
||||
else if (daemon) {
|
||||
if (setuidMode)
|
||||
throw Error("daemon cannot be started in setuid mode");
|
||||
chdir("/");
|
||||
daemonLoop();
|
||||
}
|
||||
|
||||
else
|
||||
throw Error("must be run in either --slave or --daemon mode");
|
||||
}
|
||||
|
||||
|
||||
|
|
|
|||
|
|
@ -1,11 +1,5 @@
|
|||
source common.sh
|
||||
|
||||
echo '*** testing slave mode ***'
|
||||
clearStore
|
||||
clearManifests
|
||||
NIX_REMOTE_=slave $SHELL ./user-envs.sh
|
||||
|
||||
echo '*** testing daemon mode ***'
|
||||
clearStore
|
||||
clearManifests
|
||||
startDaemon
|
||||
|
|
|
|||
Loading…
Reference in a new issue