Add support to send the string 'PXEClient' as the Vendor class

identifier to the DHCP server.  Now you can check for this string
in your dhcp configuration to decide whether you will hand out a
lease to the client or not.

3 files changed, 32 insertions, 4 deletions

diff --git a/lib/libstand/bootp.c b/lib/libstand/bootp.c
index 35ccf7a..c440c98 100644
--- a/lib/libstand/bootp.c
+++ b/lib/libstand/bootp.c
@@ -37,6 +37,7 @@
  * SUCH DAMAGE.
  *
  * @(#) Header: bootp.c,v 1.4 93/09/11 03:13:51 leres Exp  (LBL)
+ * $FreeBSD$
  */
 
 #include <sys/types.h>
@@ -80,8 +81,9 @@ struct in_addr dhcp_serverip;
 
 /* Fetch required bootp infomation */
 void
-bootp(sock)
+bootp(sock, flag)
 	int sock;
+	int flag;
 {
 	struct iodesc *d;
 	register struct bootp *bp;
@@ -124,7 +126,19 @@ bootp(sock)
 	bp->bp_vend[4] = TAG_DHCP_MSGTYPE;
 	bp->bp_vend[5] = 1;
 	bp->bp_vend[6] = DHCPDISCOVER;
-	bp->bp_vend[7] = TAG_END;
+
+	/*
+	 * If we are booting from PXE, we want to send the string
+	 * 'PXEClient' to the DHCP server so you have the option of
+	 * only responding to PXE aware dhcp requests.
+	 */
+	if (flag & BOOTP_PXE) {
+		bp->bp_vend[7] = TAG_CLASSID;
+		bp->bp_vend[8] = 9;
+		bcopy("PXEClient", &bp->bp_vend[9], 9);
+		bp->bp_vend[18] = TAG_END;
+	} else
+		bp->bp_vend[7] = TAG_END;
 #else
 	bp->bp_vend[4] = TAG_END;
 #endif
@@ -161,7 +175,13 @@ bootp(sock)
 		bp->bp_vend[20] = 4;
 		leasetime = htonl(300);
 		bcopy(&leasetime, &bp->bp_vend[21], 4);
-		bp->bp_vend[25] = TAG_END;
+		if (flag & BOOTP_PXE) {
+			bp->bp_vend[25] = TAG_CLASSID;
+			bp->bp_vend[26] = 9;
+			bcopy("PXEClient", &bp->bp_vend[27], 9);
+			bp->bp_vend[36] = TAG_END;
+		} else
+			bp->bp_vend[25] = TAG_END;
 
 		expected_dhcpmsgtype = DHCPACK;
 
diff --git a/lib/libstand/bootp.h b/lib/libstand/bootp.h
index 7435e3c..ed9101f 100644
--- a/lib/libstand/bootp.h
+++ b/lib/libstand/bootp.h
@@ -18,6 +18,8 @@
  * University.  Carnegie Mellon makes no representations about the
  * suitability of this software for any purpose.  It is provided "as is"
  * without express or implied warranty.
+ *
+ * $FreeBSD$
  */
 
 
@@ -118,6 +120,12 @@ struct bootp {
 #endif
 
 /*
+ * bootp flags
+ */
+#define	BOOTP_NONE		0x0000		/* No flags */
+#define	BOOTP_PXE		0x0001		/* Booting from PXE. */
+
+/*
  * "vendor" data permitted for CMU bootp clients.
  */
 
diff --git a/lib/libstand/net.h b/lib/libstand/net.h
index 47ff0a0..24534af 100644
--- a/lib/libstand/net.h
+++ b/lib/libstand/net.h
@@ -114,7 +114,7 @@ ssize_t	sendrecv(struct iodesc *,
 			void *, size_t);
 
 /* bootp/DHCP */
-void	bootp(int);
+void	bootp(int, int);
 
 /* Utilities: */
 char	*ether_sprintf(u_char *);