logging/vty: fix vty_read_file(): do not write warnings to stdin
Setting vty->fd to 0 is a bad idea, which may cause the process
to write() warnings to its own _stdin_ (yes, it's possible).
For example, when a configuration file contains deprecated
logging commands. Let's use stderr by default.
Change-Id: Icdeaea67a06da3a2f07b252e455629559ecc1829
diff --git a/src/vty/vty.c b/src/vty/vty.c
index babe0ef..3357d5a 100644
--- a/src/vty/vty.c
+++ b/src/vty/vty.c
@@ -1468,11 +1468,15 @@
struct vty *vty;
vty = vty_new();
- vty->fd = 0;
vty->type = VTY_FILE;
vty->node = CONFIG_NODE;
vty->priv = priv;
+ /* By default, write to stderr. Otherwise, during parsing of the logging
+ * configuration, all invocations to vty_out() would make the process
+ * write() to its own stdin (fd=0)! */
+ vty->fd = fileno(stderr);
+
ret = config_from_file(vty, confp);
if (ret != CMD_SUCCESS) {