* cygheap.h (cygheap_user::issetuid): New method.

* dtable.cc (dtable::vfork_child_dup): Use new method to determine if we are in
"setuid mode."
* fork.cc (fork_parent): Ditto.
* spawn.cc (spawn_guts): Ditto.
* syscalls.cc (seteuid32): Ditto.
(setegid32): Ditto.
* environ.cc (spenv::retrieve): (Suggested by Pierre Humblet) Do potential
recalculation of cygheap_user stuff when in setuid mode.  Return special value
when environment variable exists but should not be added.
(build_env): Don't add retrieved value to dstp if it is 'dont_add'.

7 files changed, 51 insertions, 26 deletions

diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index cfe5ec628..85b3aae06 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,5 +1,20 @@
 2002-06-16  Christopher Faylor  <cgf@redhat.com>
 
+	* cygheap.h (cygheap_user::issetuid): New method.
+	* dtable.cc (dtable::vfork_child_dup): Use new method to determine if
+	we are in "setuid mode."
+	* fork.cc (fork_parent): Ditto.
+	* spawn.cc (spawn_guts): Ditto.
+	* syscalls.cc (seteuid32): Ditto.
+	(setegid32): Ditto.
+	* environ.cc (spenv::retrieve): (Suggested by Pierre Humblet) Do
+	potential recalculation of cygheap_user stuff when in setuid mode.
+	Return special value when environment variable exists but should not be
+	added.
+	(build_env): Don't add retrieved value to dstp if it is 'dont_add'.
+
+2002-06-16  Christopher Faylor  <cgf@redhat.com>
+
 	Changes suggested by Pierre Humblet.
 	* environ.cc (NL): New macro.
 	(conv_envvars): Use NL macro to fill in name and namelen.
diff --git a/winsup/cygwin/cygheap.h b/winsup/cygwin/cygheap.h
index 032f6a40a..ff598e548 100644
--- a/winsup/cygwin/cygheap.h
+++ b/winsup/cygwin/cygheap.h
@@ -144,6 +144,10 @@ public:
   PSID sid () const { return psid; }
   PSID orig_sid () const { return orig_psid; }
   const char *ontherange (homebodies what, struct passwd * = NULL);
+  bool issetuid () const
+  {
+    return impersonated && token != INVALID_HANDLE_VALUE;
+  }
 };
 
 /* cwd cache stuff.  */
diff --git a/winsup/cygwin/dtable.cc b/winsup/cygwin/dtable.cc
index 241528a3d..b94e9cf38 100644
--- a/winsup/cygwin/dtable.cc
+++ b/winsup/cygwin/dtable.cc
@@ -618,7 +618,7 @@ dtable::vfork_child_dup ()
   int res = 1;
 
   /* Remove impersonation */
-  if (cygheap->user.impersonated && cygheap->user.token != INVALID_HANDLE_VALUE)
+  if (cygheap->user.issetuid ())
     RevertToSelf ();
 
   for (size_t i = 0; i < size; i++)
@@ -638,7 +638,7 @@ dtable::vfork_child_dup ()
 
 out:
   /* Restore impersonation */
-  if (cygheap->user.impersonated && cygheap->user.token != INVALID_HANDLE_VALUE)
+  if (cygheap->user.issetuid ())
     ImpersonateLoggedOnUser (cygheap->user.token);
 
   ReleaseResourceLock (LOCK_FD_LIST, WRITE_LOCK | READ_LOCK, "dup");
diff --git a/winsup/cygwin/environ.cc b/winsup/cygwin/environ.cc
index 9fab98619..12ae6e76f 100644
--- a/winsup/cygwin/environ.cc
+++ b/winsup/cygwin/environ.cc
@@ -760,6 +760,8 @@ struct spenv
     __attribute__ ((regparm (3)));
 };
 
+char env_dontadd[] = "";
+
 /* Keep this list in upper case and sorted */
 static NO_COPY spenv spenvs[] =
 {
@@ -781,18 +783,21 @@ spenv::retrieve (bool no_envblock, const char *const envname)
   if (from_cygheap)
     {
       const char *p;
-      if (!envname)
-	return NULL;			/* No need to force these into the
+      if (!cygheap->user.issetuid ())
+	{
+	  if (!envname)
+	    return NULL;		/* No need to force these into the
 					   environment */
 
-      if (no_envblock)
-	return cstrdup1 (envname);	/* Don't really care what it's set to
+	  if (no_envblock)
+	    return cstrdup1 (envname);	/* Don't really care what it's set to
 					   if we're calling a cygwin program */
+	}
 
-      /* Make a FOO=BAR entry from the value returned by the cygheap_user
-         method. */
-      if (!(p = (cygheap->user.*from_cygheap) ()))
-        return NULL;
+      /* Calculate (potentially) value for given environment variable.  */
+      p = (cygheap->user.*from_cygheap) ();
+      if (!p || (no_envblock && !envname))
+        return env_dontadd;
       char *s = (char *) cmalloc (HEAP_1_STR, namelen + strlen (p) + 1);
       strcpy (s, name);
       (void) strcpy (s + namelen, p);
@@ -846,23 +851,28 @@ build_env (const char * const *envp, char *&envblock, int &envc,
   int tl = 0;
   /* Iterate over input list, generating a new environment list and refreshing
      "special" entries, if necessary. */
-  for (srcp = envp, dstp = newenv; *srcp; srcp++, dstp++)
+  for (srcp = envp, dstp = newenv; *srcp; srcp++)
     {
       /* Look for entries that require special attention */
       for (unsigned i = 0; i < SPENVS_SIZE; i++)
 	if (!saw_spenv[i] && (*dstp = spenvs[i].retrieve (no_envblock, *srcp)))
 	  {
 	    saw_spenv[i] = 1;
-	    goto next;
+	    if (*dstp == env_dontadd)
+	      goto next1;
+	    goto  next0;
 	  }
 
       /* Add entry to new environment */
       *dstp = cstrdup1 (*srcp);
 
-    next:
+    next0:
       /* If necessary, calculate rough running total for envblock size */
       if (!no_envblock)
 	tl += strlen (*dstp) + 1;
+      dstp++;
+    next1:
+      continue;
     }
 
   /* Fill in any required-but-missing environment variables. */
@@ -870,7 +880,7 @@ build_env (const char * const *envp, char *&envblock, int &envc,
     if (!saw_spenv[i])
       {
 	*dstp = spenvs[i].retrieve (no_envblock);
-	if (*dstp)
+	if (*dstp && *dstp != env_dontadd)
 	  {
 	    if (!no_envblock)
 	      tl += strlen (*dstp) + 1;
diff --git a/winsup/cygwin/fork.cc b/winsup/cygwin/fork.cc
index 7a7cac0ba..e6fb91037 100644
--- a/winsup/cygwin/fork.cc
+++ b/winsup/cygwin/fork.cc
@@ -441,7 +441,7 @@ fork_parent (HANDLE& hParent, dll *&first_dll,
   si.cbReserved2 = sizeof(ch);
 
   /* Remove impersonation */
-  if (cygheap->user.impersonated && cygheap->user.token != INVALID_HANDLE_VALUE)
+  if (cygheap->user.issetuid ())
     RevertToSelf ();
 
   ch.parent = hParent;
@@ -490,8 +490,7 @@ fork_parent (HANDLE& hParent, dll *&first_dll,
       ForceCloseHandle(subproc_ready);
       ForceCloseHandle(forker_finished);
       /* Restore impersonation */
-      if (cygheap->user.impersonated
-	  && cygheap->user.token != INVALID_HANDLE_VALUE)
+      if (cygheap->user.issetuid ())
 	ImpersonateLoggedOnUser (cygheap->user.token);
       cygheap_setup_for_child_cleanup (newheap, &ch, 0);
       return -1;
@@ -519,7 +518,7 @@ fork_parent (HANDLE& hParent, dll *&first_dll,
   strcpy(forked->progname, myself->progname);
 
   /* Restore impersonation */
-  if (cygheap->user.impersonated && cygheap->user.token != INVALID_HANDLE_VALUE)
+  if (cygheap->user.issetuid ())
     ImpersonateLoggedOnUser (cygheap->user.token);
 
   ProtectHandle (pi.hThread);
diff --git a/winsup/cygwin/spawn.cc b/winsup/cygwin/spawn.cc
index 195bfcf4b..909cb0008 100644
--- a/winsup/cygwin/spawn.cc
+++ b/winsup/cygwin/spawn.cc
@@ -610,7 +610,7 @@ spawn_guts (const char * prog_arg, const char *const *argv,
   cygbench ("spawn-guts");
   ciresrv.mount_h = cygwin_mount_h;
 
-  if (!cygheap->user.impersonated || cygheap->user.token == INVALID_HANDLE_VALUE)
+  if (!cygheap->user.issetuid ())
     {
       PSECURITY_ATTRIBUTES sec_attribs = sec_user_nih (sa_buf);
       ciresrv.moreinfo->envp = build_env (envp, envblock, ciresrv.moreinfo->envc,
diff --git a/winsup/cygwin/syscalls.cc b/winsup/cygwin/syscalls.cc
index 1f6fab536..1bce92f0b 100644
--- a/winsup/cygwin/syscalls.cc
+++ b/winsup/cygwin/syscalls.cc
@@ -2093,9 +2093,8 @@ seteuid32 (__uid32_t uid)
  failed:
   cygheap->user.token = sav_token;
   cygheap->user.impersonated = sav_impersonated;
-  if ( cygheap->user.token != INVALID_HANDLE_VALUE &&
-       cygheap->user.impersonated &&
-       !ImpersonateLoggedOnUser (cygheap->user.token))
+  if (cygheap->user.issetuid ()
+       && !ImpersonateLoggedOnUser (cygheap->user.token))
     system_printf ("Impersonating in seteuid failed: %E");
   return -1;
 }
@@ -2144,8 +2143,7 @@ setegid32 (__gid32_t gid)
   myself->gid = gid;
 
   /* If impersonated, update primary group and revert */
-  if (cygheap->user.token != INVALID_HANDLE_VALUE
-      && cygheap->user.impersonated)
+  if (cygheap->user.issetuid ())
     {
       if (!SetTokenInformation (cygheap->user.token,
 				TokenPrimaryGroup,
@@ -2166,8 +2164,7 @@ setegid32 (__gid32_t gid)
 		      "TokenPrimaryGroup): %E");
       CloseHandle (ptok);
     }
-  if (cygheap->user.token != INVALID_HANDLE_VALUE
-      && cygheap->user.impersonated
+  if (cygheap->user.issetuid ()
       && !ImpersonateLoggedOnUser (cygheap->user.token))
     system_printf ("Impersonating in setegid failed: %E");
   return 0;