Use RFC4390 whenever hardware address exceeds 16 bytes; this allows us

to construct DHCP packets suitable for Infiniband.

diff --git a/src/include/gpxe/dhcp.h b/src/include/gpxe/dhcp.h
index 43bccf1..18baa86 100644 (file)
--- a/src/include/gpxe/dhcp.h
+++ b/src/include/gpxe/dhcp.h
@@ -432,6 +432,13 @@ struct dhcphdr {
 /** Opcode for a reply from server to client */
 #define BOOTP_REPLY 2
 
+/** BOOTP reply must be broadcast
+ *
+ * Clients that cannot accept unicast BOOTP replies must set this
+ * flag.
+ */
+#define BOOTP_FL_BROADCAST 0x8000
+
 /** DHCP magic cookie */
 #define DHCP_MAGIC_COOKIE 0x63825363UL
 

diff --git a/src/net/udp/dhcp.c b/src/net/udp/dhcp.c
index 9e48fe1..8e34ccb 100644 (file)
--- a/src/net/udp/dhcp.c
+++ b/src/net/udp/dhcp.c
@@ -298,6 +298,7 @@ static int create_dhcp_packet ( struct net_device *netdev, uint8_t msgtype,
                                void *data, size_t max_len,
                                struct dhcp_packet *dhcppkt ) {
        struct dhcphdr *dhcphdr = data;
+       unsigned int hlen;
        int rc;
 
        /* Sanity check */
@@ -309,9 +310,17 @@ static int create_dhcp_packet ( struct net_device *netdev, uint8_t msgtype,
        dhcphdr->xid = dhcp_xid ( netdev );
        dhcphdr->magic = htonl ( DHCP_MAGIC_COOKIE );
        dhcphdr->htype = ntohs ( netdev->ll_protocol->ll_proto );
-       dhcphdr->hlen = netdev->ll_protocol->ll_addr_len;
-       memcpy ( dhcphdr->chaddr, netdev->ll_addr, dhcphdr->hlen );
        dhcphdr->op = dhcp_op[msgtype];
+       /* If hardware length exceeds the chaddr field length, don't
+        * use the chaddr field.  This is as per RFC4390.
+        */
+       hlen = netdev->ll_protocol->ll_addr_len;
+       if ( hlen > sizeof ( dhcphdr->chaddr ) ) {
+               hlen = 0;
+               dhcphdr->flags = htons ( BOOTP_FL_BROADCAST );
+       }
+       dhcphdr->hlen = hlen;
+       memcpy ( dhcphdr->chaddr, netdev->ll_addr, hlen );
 
        /* Initialise DHCP packet structure */
        dhcppkt->dhcphdr = dhcphdr;
@@ -494,6 +503,14 @@ struct dhcp_netdev_desc {
        uint16_t device;
 } __attribute__ (( packed ));
 
+/** DHCP client identifier */
+struct dhcp_client_id {
+       /** Link-layer protocol */
+       uint8_t ll_proto;
+       /** Link-layer address */
+       uint8_t ll_addr[MAX_LL_ADDR_LEN];
+} __attribute__ (( packed ));
+
 /**
  * Create DHCP request
  *
@@ -511,7 +528,9 @@ int create_dhcp_request ( struct net_device *netdev, int msgtype,
                          struct dhcp_packet *dhcppkt ) {
        struct device_description *desc = &netdev->dev->desc;
        struct dhcp_netdev_desc dhcp_desc;
+       struct dhcp_client_id client_id;
        size_t dhcp_features_len;
+       size_t ll_addr_len;
        int rc;
 
        /* Create DHCP packet */
@@ -570,6 +589,21 @@ int create_dhcp_request ( struct net_device *netdev, int msgtype,
                return rc;
        }
 
+       /* Add DHCP client identifier.  Required for Infiniband, and
+        * doesn't hurt other link layers.
+        */
+       client_id.ll_proto = netdev->ll_protocol->ll_proto;
+       ll_addr_len = netdev->ll_protocol->ll_addr_len;
+       assert ( ll_addr_len <= sizeof ( client_id.ll_addr ) );
+       memcpy ( client_id.ll_addr, netdev->ll_addr, ll_addr_len );
+       if ( ( rc = set_dhcp_packet_option ( dhcppkt, DHCP_CLIENT_ID,
+                                            &client_id,
+                                            ( ll_addr_len + 1 ) ) ) != 0 ) {
+               DBG ( "DHCP could not set client ID: %s\n",
+                     strerror ( rc ) );
+               return rc;
+       }
+
        return 0;
 }