[PATCH 4/5] udhcpc: obtain hostname from OS by default

[Andreas Oberritter]

* Doesn't require the 'hostname' option in /etc/network/interfaces,
  and thus makes udhcpc behave like other clients.

Signed-off-by: Andreas Oberritter <obi at opendreambox.org>
---
 networking/udhcp/dhcpc.c |    9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index fe2e681..35487b6 100644
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -1375,6 +1375,15 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
 		logmode |= LOGMODE_SYSLOG;
 	}
 
+	/* try to get hostname from OS */
+	if (!client_config.hostname) {
+		char hostname[256];	/* SUSv2: hostnames are <= 255 bytes */
+		if (gethostname(hostname, sizeof(hostname)) == 0) {
+			hostname[sizeof(hostname) - 1] = '\0';
+			client_config.hostname = alloc_dhcp_option(DHCP_HOST_NAME, hostname, 0);
+		}
+	}
+
 	/* Make sure fd 0,1,2 are open */
 	bb_sanitize_stdio();
 	/* Equivalent of doing a fflush after every \n */
-- 
1.7.10.4