From: Roy Marples <roy@marples.name>
Date: Sun, 13 Apr 2008 13:17:03 +0000 (+0000)
Subject: We now use either dig or host to lookup the hostname in DNS again.
X-Git-Tag: v4.0.2~502
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=312840d8496b8610e0f3b054930ec9387aed3171;p=thirdparty%2Fdhcpcd.git

We now use either dig or host to lookup the hostname in DNS again.
---

diff --git a/dhcpcd.8.in b/dhcpcd.8.in
index 36481bd0..71d964de 100644
--- a/dhcpcd.8.in
+++ b/dhcpcd.8.in
@@ -79,7 +79,8 @@ will also attempt to restart the respective services to notify them of the
 change.
 If the hostname is currenly blank, (null) or localhost then
 .Nm
-will set the hostname to the one supplied by the DHCP server.
+will set the hostname to the one supplied by the DHCP server, or look it up
+in DNS if none supplied.
 .Nm
 then daemonises and waits for the lease renewal time to lapse.
 Then it attempts to renew its lease and reconfigure if the new lease changes.
@@ -231,7 +232,8 @@ dhcpcd itself never does any DNS updates.
 .It Fl H , --sethostname
 Forces
 .Nm
-to set the hostname as supplied by the DHCP server.
+to set the hostname as supplied by the DHCP server, or look it up
+in DNS if none supplied.
 .It Fl I , -clientid Ar clientid
 Send
 .Ar clientid
diff --git a/dhcpcd.sh b/dhcpcd.sh
index 12e90e4d..1861e3e1 100755
--- a/dhcpcd.sh
+++ b/dhcpcd.sh
@@ -1,5 +1,4 @@
 #!/bin/sh
-# 
 # dhcpcd - DHCP client daemon
 # Copyright 2006-2008 Roy Marples <roy@marples.name>
 # All rights reserved
@@ -230,11 +229,23 @@ need_hostname()
 	return 1
 }
 
+lookup_hostname()
+{
+	if type host >/dev/null 2>&1; then
+		host "${IPADDR}" | sed 's/.* domain name pointer \(.*\)./\1/'
+	elif type dig >/dev/null 2>&1; then
+		dig +short -x "${IPADDR}" | sed 's/\.$//'
+	else
+		return 1
+	fi
+}
+
 make_hostname()
 {
-	[ -z "${HOSTNAME}" ] && return 0
-	if need_hostname || yesno "${PEERHOSTNAME}"; then
-		hostname "${HOSTNAME}"
+	if yesno "${PEERHOSTNAME}" || need_hostname; then
+		local name="${HOSTNAME}"
+		[ -z "${name}" ] && name="$(lookup_hostname)"
+		[ -n "${name}" ] && hostname "${name}"
 	fi
 }