[klibc] [PATCH] ipconfig: send hostname in DHCP request

[Aron Griffis]

If a hostname is requested, for example -d ::::foo::dhcp, then include the
hostname in the DHCP discover/request.  This patch also allows
the vendor class identifier to be omitted from the DHCP
discover/request by specifying -i ""

Signed-off-by: Aron Griffis <agriffis at n01se.net>
---
 usr/kinit/ipconfig/dhcp_proto.c |   49 ++++++++++++++++++++++++++++++--------
 usr/kinit/ipconfig/main.c       |    4 +++
 usr/kinit/ipconfig/netdev.h     |    1 +
 3 files changed, 43 insertions(+), 11 deletions(-)

diff --git a/usr/kinit/ipconfig/dhcp_proto.c b/usr/kinit/ipconfig/dhcp_proto.c
index d4f2c09..775a5ca 100644
--- a/usr/kinit/ipconfig/dhcp_proto.c
+++ b/usr/kinit/ipconfig/dhcp_proto.c
@@ -49,24 +49,26 @@ static uint8_t dhcp_end[] = {
 
 /* Both iovecs below have to have the same structure, since dhcp_send()
    pokes at the internals */
-#define DHCP_IOV_LEN 6
+#define DHCP_IOV_LEN 7
 
-static struct iovec dhcp_discover_iov[] = {
+static struct iovec dhcp_discover_iov[DHCP_IOV_LEN] = {
 	/* [0] = ip + udp header */
 	/* [1] = bootp header */
 	[2] = {dhcp_discover_hdr, sizeof(dhcp_discover_hdr)},
 	[3] = {dhcp_params, sizeof(dhcp_params)},
-	/* [4] = DHCP vendor class */
-	[5] = {dhcp_end, sizeof(dhcp_end)}
+	/* [4] = optional vendor class */
+	/* [5] = optional hostname */
+	/* [6] = {dhcp_end, sizeof(dhcp_end)} */
 };
 
-static struct iovec dhcp_request_iov[] = {
+static struct iovec dhcp_request_iov[DHCP_IOV_LEN] = {
 	/* [0] = ip + udp header */
 	/* [1] = bootp header */
 	[2] = {dhcp_request_hdr, sizeof(dhcp_request_hdr)},
 	[3] = {dhcp_params, sizeof(dhcp_params)},
-	/* [4] = DHCP vendor class */
-	[5] = {dhcp_end, sizeof(dhcp_end)}
+	/* [4] = optional vendor class */
+	/* [5] = optional hostname */
+	/* [6] = {dhcp_end, sizeof(dhcp_end)} */
 };
 
 /*
@@ -164,6 +166,8 @@ static int dhcp_recv(struct netdev *dev)
 static int dhcp_send(struct netdev *dev, struct iovec *vec)
 {
 	struct bootp_hdr bootp;
+	char dhcp_hostname[SYS_NMLN+2];
+	int i = 4;
 
 	memset(&bootp, 0, sizeof(struct bootp_hdr));
 
@@ -179,12 +183,35 @@ static int dhcp_send(struct netdev *dev, struct iovec *vec)
 	vec[1].iov_base	= &bootp;
 	vec[1].iov_len	= sizeof(struct bootp_hdr);
 
-	vec[4].iov_base = vendor_class_identifier;
-	vec[4].iov_len  = vendor_class_identifier_len;
-
 	DEBUG(("xid %08x secs %d ", bootp.xid, ntohs(bootp.secs)));
 
-	return packet_send(dev, vec, DHCP_IOV_LEN);
+	if (vendor_class_identifier_len > 2) {
+		vec[i].iov_base = vendor_class_identifier;
+		vec[i].iov_len  = vendor_class_identifier_len;
+		i++;
+
+		DEBUG(("vendor_class_identifier \"%.*s\" ", 
+		       vendor_class_identifier_len-2, 
+		       vendor_class_identifier+2));
+	}
+
+	if (dev->reqhostname[0] != '\0') {
+		int len = strlen(dev->reqhostname);
+		dhcp_hostname[0] = 12;
+		dhcp_hostname[1] = len;
+		memcpy(dhcp_hostname+2, dev->reqhostname, len);
+
+		vec[i].iov_base = dhcp_hostname;
+		vec[i].iov_len  = len+2;
+		i++;
+
+		DEBUG(("hostname %.*s ", len, dhcp_hostname+2));
+	}
+
+	vec[i].iov_base = dhcp_end;
+	vec[i].iov_len  = sizeof(dhcp_end);
+
+	return packet_send(dev, vec, i);
 }
 
 /*
diff --git a/usr/kinit/ipconfig/main.c b/usr/kinit/ipconfig/main.c
index 2ded0f3..619edf7 100644
--- a/usr/kinit/ipconfig/main.c
+++ b/usr/kinit/ipconfig/main.c
@@ -522,6 +522,8 @@ static int parse_device(struct netdev *dev, const char *ip)
 			case 4:
 				strncpy(dev->hostname, ip, SYS_NMLN - 1);
 				dev->hostname[SYS_NMLN - 1] = '\0';
+				memcpy(dev->reqhostname, dev->hostname, 
+				       SYS_NMLN);
 				break;
 			case 5:
 				dev->name = ip;
@@ -569,6 +571,8 @@ static void bringup_one_dev(struct netdev *template, struct netdev *dev)
 		dev->ip_nameserver[1] = template->ip_nameserver[1];
 	if (template->hostname[0] != '\0')
 		strcpy(dev->hostname, template->hostname);
+	if (template->reqhostname[0] != '\0')
+		strcpy(dev->reqhostname, template->reqhostname);
 	dev->caps &= template->caps;
 
 	bringup_device(dev);
diff --git a/usr/kinit/ipconfig/netdev.h b/usr/kinit/ipconfig/netdev.h
index fb6640a..a25a544 100644
--- a/usr/kinit/ipconfig/netdev.h
+++ b/usr/kinit/ipconfig/netdev.h
@@ -35,6 +35,7 @@ struct netdev {
 	uint32_t ip_gateway;	/* my gateway           */
 	uint32_t ip_nameserver[2];	/* two nameservers      */
 	uint32_t serverid;		/* dhcp serverid        */
+	char reqhostname[SYS_NMLN];	/* requested hostname   */
 	char hostname[SYS_NMLN];	/* hostname             */
 	char dnsdomainname[SYS_NMLN];	/* dns domain name      */
 	char nisdomainname[SYS_NMLN];	/* nis domain name      */
-- 
1.6.0.4