dhcp: Remove option 255 length byte

The option 255 (end of options) do not need the length byte, this change
remove that allowing to have one extra byte at other dynamic options.

Signed-off-by: Enrique Llorente <ellorent@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

1 files changed, 3 insertions, 4 deletions

diff --git a/dhcp.c b/dhcp.c
index 401cb5b..4a209f1 100644
--- a/dhcp.c
+++ b/dhcp.c
@@ -64,9 +64,9 @@ static struct opt opts[255];
 #define OPT_MIN		60 /* RFC 951 */
 
 /* Total option size (excluding end option) is 576 (RFC 2131), minus
- * offset of options (268), minus end option and its length (2).
+ * offset of options (268), minus end option (1).
  */
-#define OPT_MAX		306
+#define OPT_MAX		307
 
 /**
  * dhcp_init() - Initialise DHCP options
@@ -127,7 +127,7 @@ struct msg {
 	uint8_t sname[64];
 	uint8_t file[128];
 	uint32_t magic;
-	uint8_t o[OPT_MAX + 2 /* End option and its length */ ];
+	uint8_t o[OPT_MAX + 1 /* End option */ ];
 } __attribute__((__packed__));
 
 /**
@@ -194,7 +194,6 @@ static int fill(struct msg *m)
 	}
 
 	m->o[offset++] = 255;
-	m->o[offset++] = 0;
 
 	if (offset < OPT_MIN) {
 		memset(&m->o[offset], 0, OPT_MIN - offset);