[dhcp] Allow for variable encapsulation of architecture-specific options

DHCPv4 and DHCPv6 share some values in common for the architecture-
specific options (such as the client system architecture type), but
use different encapsulations: DHCPv4 has a single byte for the option
length while DHCPv6 has a 16-bit field for the option length.

Move the containing DHCP_OPTION() and related wrappers from the
individual dhcp_arch.h files to dhcp.c, thus allowing for the
architecture-specific values to be reused in dhcpv6.c.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/arch/arm32/include/efi/ipxe/dhcp_arch.h

 
 #include <ipxe/dhcp.h>
 
-#define DHCP_ARCH_VENDOR_CLASS_ID \
-	DHCP_STRING ( 'P', 'X', 'E', 'C', 'l', 'i', 'e', 'n', 't', ':',      \
-		      'A', 'r', 'c', 'h', ':', '0', '0', '0', '0', '7', ':', \
-		      'U', 'N', 'D', 'I', ':', '0', '0', '3', '0', '1', '0' )
+#define DHCP_ARCH_VENDOR_CLASS_ID				\
+	'P', 'X', 'E', 'C', 'l', 'i', 'e', 'n', 't', ':',	\
+	'A', 'r', 'c', 'h', ':', '0', '0', '0', '0', '7', ':',	\
+	'U', 'N', 'D', 'I', ':', '0', '0', '3', '0', '1', '0'
 
-#define DHCP_ARCH_CLIENT_ARCHITECTURE \
-	DHCP_WORD ( DHCP_CLIENT_ARCHITECTURE_ARM32 )
+#define DHCP_ARCH_CLIENT_ARCHITECTURE DHCP_CLIENT_ARCHITECTURE_ARM32
 
-#define DHCP_ARCH_CLIENT_NDI DHCP_OPTION ( 1 /* UNDI */ , 3, 10 /* v3.10 */ )
+#define DHCP_ARCH_CLIENT_NDI 1 /* UNDI */ , 3, 10 /* v3.10 */
 
 #endif

src/arch/arm64/include/efi/ipxe/dhcp_arch.h

 
 #include <ipxe/dhcp.h>
 
-#define DHCP_ARCH_VENDOR_CLASS_ID \
-	DHCP_STRING ( 'P', 'X', 'E', 'C', 'l', 'i', 'e', 'n', 't', ':',      \
-		      'A', 'r', 'c', 'h', ':', '0', '0', '0', '0', '7', ':', \
-		      'U', 'N', 'D', 'I', ':', '0', '0', '3', '0', '1', '0' )
+#define DHCP_ARCH_VENDOR_CLASS_ID				\
+	'P', 'X', 'E', 'C', 'l', 'i', 'e', 'n', 't', ':',	\
+	'A', 'r', 'c', 'h', ':', '0', '0', '0', '0', '7', ':',	\
+	'U', 'N', 'D', 'I', ':', '0', '0', '3', '0', '1', '0'
 
-#define DHCP_ARCH_CLIENT_ARCHITECTURE \
-	DHCP_WORD ( DHCP_CLIENT_ARCHITECTURE_ARM64 )
+#define DHCP_ARCH_CLIENT_ARCHITECTURE DHCP_CLIENT_ARCHITECTURE_ARM64
 
-#define DHCP_ARCH_CLIENT_NDI DHCP_OPTION ( 1 /* UNDI */ , 3, 10 /* v3.10 */ )
+#define DHCP_ARCH_CLIENT_NDI 1 /* UNDI */ , 3, 10 /* v3.10 */
 
 #endif

src/arch/i386/include/efi/ipxe/dhcp_arch.h

 
 #include <ipxe/dhcp.h>
 
-#define DHCP_ARCH_VENDOR_CLASS_ID \
-	DHCP_STRING ( 'P', 'X', 'E', 'C', 'l', 'i', 'e', 'n', 't', ':',      \
-		      'A', 'r', 'c', 'h', ':', '0', '0', '0', '0', '6', ':', \
-		      'U', 'N', 'D', 'I', ':', '0', '0', '3', '0', '1', '0' )
+#define DHCP_ARCH_VENDOR_CLASS_ID				\
+	'P', 'X', 'E', 'C', 'l', 'i', 'e', 'n', 't', ':',	\
+	'A', 'r', 'c', 'h', ':', '0', '0', '0', '0', '6', ':',	\
+	'U', 'N', 'D', 'I', ':', '0', '0', '3', '0', '1', '0'
 
-#define DHCP_ARCH_CLIENT_ARCHITECTURE \
-	DHCP_WORD ( DHCP_CLIENT_ARCHITECTURE_IA32 )
+#define DHCP_ARCH_CLIENT_ARCHITECTURE DHCP_CLIENT_ARCHITECTURE_IA32
 
-#define DHCP_ARCH_CLIENT_NDI DHCP_OPTION ( 1 /* UNDI */ , 3, 10 /* v3.10 */ )
+#define DHCP_ARCH_CLIENT_NDI 1 /* UNDI */ , 3, 10 /* v3.10 */
 
 #endif

src/arch/i386/include/pcbios/ipxe/dhcp_arch.h

 
 #include <ipxe/dhcp.h>
 
-#define DHCP_ARCH_VENDOR_CLASS_ID \
-	DHCP_STRING ( 'P', 'X', 'E', 'C', 'l', 'i', 'e', 'n', 't', ':',      \
-		      'A', 'r', 'c', 'h', ':', '0', '0', '0', '0', '0', ':', \
-		      'U', 'N', 'D', 'I', ':', '0', '0', '2', '0', '0', '1' )
+#define DHCP_ARCH_VENDOR_CLASS_ID				\
+	'P', 'X', 'E', 'C', 'l', 'i', 'e', 'n', 't', ':',	\
+	'A', 'r', 'c', 'h', ':', '0', '0', '0', '0', '0', ':',	\
+	'U', 'N', 'D', 'I', ':', '0', '0', '2', '0', '0', '1'
 
-#define DHCP_ARCH_CLIENT_ARCHITECTURE \
-	DHCP_WORD ( DHCP_CLIENT_ARCHITECTURE_X86 )
+#define DHCP_ARCH_CLIENT_ARCHITECTURE DHCP_CLIENT_ARCHITECTURE_X86
 
-#define DHCP_ARCH_CLIENT_NDI DHCP_OPTION ( 1 /* UNDI */ , 2, 1 /* v2.1 */ )
+#define DHCP_ARCH_CLIENT_NDI 1 /* UNDI */ , 2, 1 /* v2.1 */
 
 #endif

src/arch/x86_64/include/efi/ipxe/dhcp_arch.h

 
 #include <ipxe/dhcp.h>
 
-#define DHCP_ARCH_VENDOR_CLASS_ID \
-	DHCP_STRING ( 'P', 'X', 'E', 'C', 'l', 'i', 'e', 'n', 't', ':',      \
-		      'A', 'r', 'c', 'h', ':', '0', '0', '0', '0', '9', ':', \
-		      'U', 'N', 'D', 'I', ':', '0', '0', '3', '0', '1', '0' )
+#define DHCP_ARCH_VENDOR_CLASS_ID				\
+	'P', 'X', 'E', 'C', 'l', 'i', 'e', 'n', 't', ':',	\
+	'A', 'r', 'c', 'h', ':', '0', '0', '0', '0', '9', ':',	\
+	'U', 'N', 'D', 'I', ':', '0', '0', '3', '0', '1', '0'
 
-#define DHCP_ARCH_CLIENT_ARCHITECTURE \
-	DHCP_WORD ( DHCP_CLIENT_ARCHITECTURE_X86_64 )
+#define DHCP_ARCH_CLIENT_ARCHITECTURE DHCP_CLIENT_ARCHITECTURE_X86_64
 
-#define DHCP_ARCH_CLIENT_NDI DHCP_OPTION ( 1 /* UNDI */ , 3, 10 /* v3.10 */ )
+#define DHCP_ARCH_CLIENT_NDI 1 /* UNDI */ , 3, 10 /* v3.10 */
 
 #endif

src/arch/x86_64/include/pcbios/ipxe/dhcp_arch.h

 
 #include <ipxe/dhcp.h>
 
-#define DHCP_ARCH_VENDOR_CLASS_ID \
-	DHCP_STRING ( 'P', 'X', 'E', 'C', 'l', 'i', 'e', 'n', 't', ':',      \
-		      'A', 'r', 'c', 'h', ':', '0', '0', '0', '0', '0', ':', \
-		      'U', 'N', 'D', 'I', ':', '0', '0', '2', '0', '0', '1' )
+#define DHCP_ARCH_VENDOR_CLASS_ID				\
+	'P', 'X', 'E', 'C', 'l', 'i', 'e', 'n', 't', ':',	\
+	'A', 'r', 'c', 'h', ':', '0', '0', '0', '0', '0', ':',	\
+	'U', 'N', 'D', 'I', ':', '0', '0', '2', '0', '0', '1'
 
-#define DHCP_ARCH_CLIENT_ARCHITECTURE \
-	DHCP_WORD ( DHCP_CLIENT_ARCHITECTURE_X86 )
+#define DHCP_ARCH_CLIENT_ARCHITECTURE DHCP_CLIENT_ARCHITECTURE_X86
 
-#define DHCP_ARCH_CLIENT_NDI DHCP_OPTION ( 1 /* UNDI */ , 2, 1 /* v2.1 */ )
+#define DHCP_ARCH_CLIENT_NDI 1 /* UNDI */ , 2, 1 /* v2.1 */
 
 #endif

src/net/udp/dhcp.c

 	DHCP_MESSAGE_TYPE, DHCP_BYTE ( 0 ),
 	DHCP_MAX_MESSAGE_SIZE,
 	DHCP_WORD ( ETH_MAX_MTU - 20 /* IP header */ - 8 /* UDP header */ ),
-	DHCP_CLIENT_ARCHITECTURE, DHCP_ARCH_CLIENT_ARCHITECTURE,
-	DHCP_CLIENT_NDI, DHCP_ARCH_CLIENT_NDI,
-	DHCP_VENDOR_CLASS_ID, DHCP_ARCH_VENDOR_CLASS_ID,
+	DHCP_CLIENT_ARCHITECTURE, DHCP_WORD ( DHCP_ARCH_CLIENT_ARCHITECTURE ),
+	DHCP_CLIENT_NDI, DHCP_OPTION ( DHCP_ARCH_CLIENT_NDI ),
+	DHCP_VENDOR_CLASS_ID, DHCP_STRING ( DHCP_ARCH_VENDOR_CLASS_ID ),
 	DHCP_USER_CLASS_ID, DHCP_STRING ( 'i', 'P', 'X', 'E' ),
 	DHCP_PARAMETER_REQUEST_LIST,
 	DHCP_OPTION ( DHCP_SUBNET_MASK, DHCP_ROUTERS, DHCP_DNS_SERVERS,