Add two new routines: fdevname() and fdevname_r().

A more elegant way of obtaining a name of a character device by its file
descriptor on FreeBSD, is to use the FIODGNAME ioctl. Because a valid
file descriptor implies a file descriptor is visible in /dev, it will
always resolve a valid device name.

I'm adding a more friendly wrapper for this ioctl, called fdevname(). It
is a lot easier to use than devname() and also has better error
handling. When a device name cannot be resolved, it will just return
NULL instead of a generated device name that makes no sense.

Discussed with:	kib

1 files changed, 2 insertions, 0 deletions

diff --git a/lib/libc/gen/Symbol.map b/lib/libc/gen/Symbol.map
index 2e64313..afdecb5 100644
--- a/lib/libc/gen/Symbol.map
+++ b/lib/libc/gen/Symbol.map
@@ -331,6 +331,8 @@ FBSD_1.0 {
 FBSD_1.1 {
 	arc4random_buf;
 	arc4random_uniform;
+	fdevname;
+	fdevname_r;
 	fdopendir;
 	feature_present;
 	fts_open;