Provide unhooked version of getenv() and use it when looking up

DISPLAY and SUDO_ASKPASS in the environment.

src/env_hooks.c

@@ -69,6 +69,19 @@ rpl_getenv(const char *name)
 
 typedef char * (*sudo_fn_getenv_t)(const char *);
 
+char *
+getenv_unhooked(const char *name)
+{
+#if defined(HAVE_DLOPEN) && defined(RTLD_NEXT)
+    sudo_fn_getenv_t fn;
+
+    fn = (sudo_fn_getenv_t)dlsym(RTLD_NEXT, "getenv");
+    if (fn != NULL)
+	return fn(name);
+#endif /* HAVE_DLOPEN && RTLD_NEXT */
+    return rpl_getenv(name);
+}
+
 char *
 getenv(const char *name)
 {
@@ -79,16 +92,8 @@ getenv(const char *name)
 	    return val;
 	case SUDO_HOOK_RET_ERROR:
 	    return NULL;
-	default: {
-#if defined(HAVE_DLOPEN) && defined(RTLD_NEXT)
-	    sudo_fn_getenv_t fn;
-
-	    fn = (sudo_fn_getenv_t)dlsym(RTLD_NEXT, "getenv");
-	    if (fn != NULL)
-		return fn(name);
-#endif /* HAVE_DLOPEN && RTLD_NEXT */
-	    return rpl_getenv(name);
-	}
+	default:
+	    return getenv_unhooked(name);
     }
 }
 
@@ -136,15 +141,9 @@ rpl_putenv(PUTENV_CONST char *string)
 
 typedef int (*sudo_fn_putenv_t)(PUTENV_CONST char *);
 
-int
-putenv(PUTENV_CONST char *string)
+static int
+putenv_unhooked(PUTENV_CONST char *string)
 {
-    switch (process_hooks_putenv((char *)string)) {
-	case SUDO_HOOK_RET_STOP:
-	    return 0;
-	case SUDO_HOOK_RET_ERROR:
-	    return -1;
-	default: {
 #if defined(HAVE_DLOPEN) && defined(RTLD_NEXT)
     sudo_fn_putenv_t fn;
 
@@ -153,7 +152,18 @@ putenv(PUTENV_CONST char *string)
 	return fn(string);
 #endif /* HAVE_DLOPEN && RTLD_NEXT */
     return rpl_putenv(string);
-	}
+}
+
+int
+putenv(PUTENV_CONST char *string)
+{
+    switch (process_hooks_putenv((char *)string)) {
+	case SUDO_HOOK_RET_STOP:
+	    return 0;
+	case SUDO_HOOK_RET_ERROR:
+	    return -1;
+	default:
+	    return putenv_unhooked(string);
     }
 }
 
@@ -201,15 +211,9 @@ rpl_setenv(const char *var, const char *val, int overwrite)
 
 typedef int (*sudo_fn_setenv_t)(const char *, const char *, int);
 
-int
-setenv(const char *var, const char *val, int overwrite)
+static int
+setenv_unhooked(const char *var, const char *val, int overwrite)
 {
-    switch (process_hooks_setenv(var, val, overwrite)) {
-	case SUDO_HOOK_RET_STOP:
-	    return 0;
-	case SUDO_HOOK_RET_ERROR:
-	    return -1;
-	default: {
 #if defined(HAVE_SETENV) && defined(HAVE_DLOPEN) && defined(RTLD_NEXT)
     sudo_fn_setenv_t fn;
 
@@ -218,15 +222,22 @@ setenv(const char *var, const char *val, int overwrite)
 	return fn(var, val, overwrite);
 #endif /* HAVE_SETENV && HAVE_DLOPEN && RTLD_NEXT */
     return rpl_setenv(var, val, overwrite);
-	}
+}
+
+int
+setenv(const char *var, const char *val, int overwrite)
+{
+    switch (process_hooks_setenv(var, val, overwrite)) {
+	case SUDO_HOOK_RET_STOP:
+	    return 0;
+	case SUDO_HOOK_RET_ERROR:
+	    return -1;
+	default:
+	    return setenv_unhooked(var, val, overwrite);
     }
 }
 
-#ifdef UNSETENV_VOID
-static void
-#else
-int
-#endif
+static int
 rpl_unsetenv(const char *var)
 {
     char **ep = environ;
@@ -234,11 +245,7 @@ rpl_unsetenv(const char *var)
 
     if (var == NULL || *var == '\0' || strchr(var, '=') != NULL) {
 	errno = EINVAL;
-#ifdef UNSETENV_VOID
-	return;
-#else
 	return -1;
-#endif
     }
 
     len = strlen(var);
@@ -253,9 +260,7 @@ rpl_unsetenv(const char *var)
 	    ep++;
 	}
     }
-#ifndef UNSETENV_VOID
     return 0;
-#endif
 }
 
 #ifdef UNSETENV_VOID
@@ -264,47 +269,49 @@ typedef void (*sudo_fn_unsetenv_t)(const char *);
 typedef int (*sudo_fn_unsetenv_t)(const char *);
 #endif
 
+static int
+unsetenv_unhooked(const char *var)
+{
+    int rval = 0;
+#if defined(HAVE_UNSETENV) && defined(HAVE_DLOPEN) && defined(RTLD_NEXT)
+    sudo_fn_unsetenv_t fn;
+
+    fn = (sudo_fn_unsetenv_t)dlsym(RTLD_NEXT, "unsetenv");
+    if (fn != NULL) {
+# ifdef UNSETENV_VOID
+	fn(var);
+# else
+	rval = fn(var);
+# endif
+    } else
+#endif /* HAVE_UNSETENV && HAVE_DLOPEN && RTLD_NEXT */
+    {
+	rval = rpl_unsetenv(var);
+    }
+    return rval;
+}
+
 #ifdef UNSETENV_VOID
 void
-unsetenv(const char *var)
-{
-    switch (process_hooks_unsetenv(var)) {
-	case SUDO_HOOK_RET_STOP:
-	    return 0;
-	case SUDO_HOOK_RET_ERROR:
-	    return -1;
-	default: {
-#if defined(HAVE_UNSETENV) && defined(HAVE_DLOPEN) && defined(RTLD_NEXT)
-	    sudo_fn_unsetenv_t fn;
-
-	    fn = (sudo_fn_unsetenv_t)dlsym(RTLD_NEXT, "unsetenv");
-	    if (fn != NULL)
-		fn(var);
-	    else
-#endif /* HAVE_UNSETENV && HAVE_DLOPEN && RTLD_NEXT */
-		rpl_unsetenv(var);
-	}
-    }
-}
 #else
 int
+#endif
 unsetenv(const char *var)
 {
+    int rval;
+
     switch (process_hooks_unsetenv(var)) {
 	case SUDO_HOOK_RET_STOP:
-	    return 0;
+	    rval = 0;
+	    break;
 	case SUDO_HOOK_RET_ERROR:
-	    return -1;
-	default: {
-#if defined(HAVE_UNSETENV) && defined(HAVE_DLOPEN) && defined(RTLD_NEXT)
-	    sudo_fn_unsetenv_t fn;
-
-	    fn = (sudo_fn_unsetenv_t)dlsym(RTLD_NEXT, "unsetenv");
-	    if (fn != NULL)
-		return fn(var);
-#endif /* HAVE_UNSETENV && HAVE_DLOPEN && RTLD_NEXT */
-	    return rpl_unsetenv(var);
-	}
+	    rval = -1;
+	    break;
+	default:
+	    rval = unsetenv_unhooked(var);
+	    break;
     }
+#ifndef UNSETENV_VOID
+    return rval;
+#endif
 }
-#endif /* UNSETENV_VOID */

src/sudo.h

@@ -237,6 +237,9 @@ int process_hooks_setenv(const char *name, const char *value, int overwrite);
 int process_hooks_putenv(char *string);
 int process_hooks_unsetenv(const char *name);
 
+/* env_hooks.c */
+char *getenv_unhooked(const char *name);
+
 /* interfaces.c */
 int get_net_ifs(char **addrinfo);
 

src/tgetpass.c

@@ -78,7 +78,7 @@ tgetpass(const char *prompt, int timeout, int flags)
     (void) fflush(stdout);
 
     if (askpass == NULL) {
-	askpass = getenv("SUDO_ASKPASS");
+	askpass = getenv_unhooked("SUDO_ASKPASS");
 	if (askpass == NULL || *askpass == '\0')
 	    askpass = sudo_conf_askpass_path();
     }
@@ -86,7 +86,7 @@ tgetpass(const char *prompt, int timeout, int flags)
     /* If no tty present and we need to disable echo, try askpass. */
     if (!ISSET(flags, TGP_STDIN|TGP_ECHO|TGP_ASKPASS|TGP_NOECHO_TRY) &&
 	!tty_present()) {
-	if (askpass == NULL || getenv("DISPLAY") == NULL) {
+	if (askpass == NULL || getenv_unhooked("DISPLAY") == NULL) {
 	    warningx(_("no tty present and no askpass program specified"));
 	    debug_return_str(NULL);
 	}