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.

2 files changed, 1 insertions, 60 deletions

diff --git a/src/libmain/shared.cc b/src/libmain/shared.cc
index f8149fc608fd..9e5964acf8bb 100644
--- a/src/libmain/shared.cc
+++ b/src/libmain/shared.cc
@@ -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));
diff --git a/src/libmain/shared.hh b/src/libmain/shared.hh
index 9e5ec8360952..b054b0717f26 100644
--- a/src/libmain/shared.hh
+++ b/src/libmain/shared.hh
@@ -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. */