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Added macros for generating static DHCP options

This commit is contained in:
Michael Brown 2006-07-19 16:16:51 +00:00
parent 254fe6e00e
commit b8d619e822
1 changed files with 60 additions and 0 deletions
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60
src/include/gpxe/dhcp.h
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@ -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 );