iovcnt can be zero, writev does not like that and O_CREATE is

not needed, we just renamed sucessfully to that file.
ok deraadt@ florian@

diff --git a/sbin/resolvd/resolvd.c b/sbin/resolvd/resolvd.c
index 9260a62..ff93c31 100644 (file)
--- a/sbin/resolvd/resolvd.c
+++ b/sbin/resolvd/resolvd.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: resolvd.c,v 1.30 2022/11/27 15:19:38 kn Exp $ */
+/*     $OpenBSD: resolvd.c,v 1.31 2022/12/09 18:11:24 otto Exp $       */
 /*
  * Copyright (c) 2021 Florian Obser <florian@openbsd.org>
  * Copyright (c) 2021 Theo de Raadt <deraadt@openbsd.org>
@@ -666,9 +666,11 @@ regen_resolvconf(const char *why)
                fclose(fp);
        }
 
-       if (writev(fd, iov, iovcnt) == -1) {
-               lwarn("writev");
-               goto err;
+       if (iovcnt > 0) {
+               if (writev(fd, iov, iovcnt) == -1) {
+                       lwarn("writev");
+                       goto err;
+               }
        }
 
        if (fsync(fd) == -1) {
@@ -680,7 +682,7 @@ regen_resolvconf(const char *why)
 
        if (resolvfd == -1) {
                close(fd);
-               resolvfd = open(_PATH_RESCONF, O_RDWR | O_CREAT);
+               resolvfd = open(_PATH_RESCONF, O_RDWR);
        } else {
                dup2(fd, resolvfd);
                close(fd);