Added macros for generating static DHCP options

[gpxe.git] / src / include / gpxe / dhcp.h

diff --git a/src/include/gpxe/dhcp.h b/src/include/gpxe/dhcp.h
index 15be77c..7f56692 100644 (file)
--- a/src/include/gpxe/dhcp.h
+++ b/src/include/gpxe/dhcp.h
@@ -10,6 +10,7 @@
 #include <stdint.h>
 #include <gpxe/list.h>
 #include <gpxe/in.h>
+#include <gpxe/udp.h>
 
 /** Construct a tag value for an encapsulated option
  *
@@ -127,6 +128,54 @@
 
 /** @} */
 
+/**
+ * Count number of arguments to a variadic macro
+ *
+ * This rather neat, non-iterative solution is courtesy of Laurent
+ * Deniau.
+ *
+ */
+#define _VA_ARG_COUNT(  _1,  _2,  _3,  _4,  _5,  _6,  _7,  _8,         \
+                       _9, _10, _11, _12, _13, _14, _15, _16,          \
+                      _17, _18, _19, _20, _21, _22, _23, _24,          \
+                      _25, _26, _27, _28, _29, _30, _31, _32,          \
+                      _33, _34, _35, _36, _37, _38, _39, _40,          \
+                      _41, _42, _43, _44, _45, _46, _47, _48,          \
+                      _49, _50, _51, _52, _53, _54, _55, _56,          \
+                      _57, _58, _59, _60, _61, _62, _63,   N, ... ) N
+#define VA_ARG_COUNT( ... )                                            \
+       _VA_ARG_COUNT ( __VA_ARGS__,                                    \
+                       63, 62, 61, 60, 59, 58, 57, 56,                 \
+                       55, 54, 53, 52, 51, 50, 49, 48,                 \
+                       47, 46, 45, 44, 43, 42, 41, 40,                 \
+                       39, 38, 37, 36, 35, 34, 33, 32,                 \
+                       31, 30, 29, 28, 27, 26, 25, 24,                 \
+                       23, 22, 21, 20, 19, 18, 17, 16,                 \
+                       15, 14, 13, 12, 11, 10,  9,  8,                 \
+                        7,  6,  5,  4,  3,  2,  1,  0 )
+
+/** Construct a DHCP option from a list of bytes */
+#define DHCP_OPTION( ... ) VA_ARG_COUNT ( __VA_ARGS__ ), __VA_ARGS__
+
+/** Construct a DHCP option from a list of characters */
+#define DHCP_STRING( ... ) DHCP_OPTION ( __VA_ARGS__ )
+
+/** Construct a byte-valued DHCP option */
+#define DHCP_BYTE( value ) DHCP_OPTION ( value )
+
+/** Construct a word-valued DHCP option */
+#define DHCP_WORD( value ) DHCP_OPTION ( ( ( (value) >> 8 ) & 0xff ),   \
+                                        ( ( (value) >> 0  ) & 0xff ) )
+
+/** Construct a dword-valued DHCP option */
+#define DHCP_DWORD( value ) DHCP_OPTION ( ( ( (value) >> 24 ) & 0xff ), \
+                                         ( ( (value) >> 16 ) & 0xff ), \
+                                         ( ( (value) >> 8  ) & 0xff ), \
+                                         ( ( (value) >> 0  ) & 0xff ) )
+
+/** Construct a DHCP encapsulated options field */
+#define DHCP_ENCAP( ... ) DHCP_OPTION ( __VA_ARGS__, DHCP_END )
+
 /**
  * A DHCP option
  *
@@ -313,12 +362,23 @@ struct dhcp_packet {
 
 /** A DHCP session */
 struct dhcp_session {
+       /** UDP connection for this session */
+       struct udp_connection udp;
+
+       /** State of the session
+        *
+        * This is a value for the @c DHCP_MESSAGE_TYPE option
+        * (e.g. @c DHCPDISCOVER).
+        */
+       int state;
+       
        /** Network device being configured */
        struct net_device *netdev;
        /** Transaction ID, in network-endian order */
        uint32_t xid;
 };
 
+extern const struct dhcp_option_block dhcp_request_options;
 extern unsigned long dhcp_num_option ( struct dhcp_option *option );
 extern struct dhcp_option *
 find_dhcp_option ( struct dhcp_option_block *options, unsigned int tag );