sysadmin/ipxe
1
0
Fork 0
mirror of https://github.com/ipxe/ipxe synced 2025-12-09 02:40:27 +03:00
Code Issues Packages Projects Releases Wiki Activity

Add code to modify DHCP option values within a block.

Browse Source
This commit is contained in:
Michael Brown
2006-07-13 20:49:04 +00:00
parent 3acbff4f00
commit 19e8b41562
2 changed files with 248 additions and 81 deletions
Download Patch File Download Diff File Expand all files Collapse all files

70
src/include/gpxe/dhcp.h
View File

@@ -23,6 +23,8 @@
/** Extract encapsulated option tag from encapsulated tag value */
#define DHCP_ENCAPSULATED( encap_opt ) ( (encap_opt) & 0xff )
#define DHCP_IS_ENCAP_OPT( opt ) DHCP_ENCAPSULATOR( opt )
/**
* @defgroup dhcpopts DHCP option tags
* @{
@@ -74,6 +76,17 @@ struct dhcp_option {
} data;
} __attribute__ (( packed ));
/**
* Length of a DHCP option header
*
* The header is the portion excluding the data, i.e. the tag and the
* length.
*/
#define DHCP_OPTION_HEADER_LEN ( offsetof ( struct dhcp_option, data ) )
/** Maximum length for a single DHCP option */
#define DHCP_MAX_LEN 0xff
/** A DHCP options block */
struct dhcp_option_block {
/** List of option blocks */
@@ -82,17 +95,35 @@ struct dhcp_option_block {
void *data;
/** Option block length */
size_t len;
/** Option block maximum length */
size_t max_len;
/** Block priority
*
* This is determined at the time of the call to
* register_options() by searching for the @c DHCP_EB_PRIORITY
* option.
*/
signed int priority;
};
extern unsigned long dhcp_num_option ( struct dhcp_option *option );
extern struct dhcp_option * find_dhcp_option ( unsigned int tag,
struct dhcp_option_block *options );
extern struct dhcp_option *
find_dhcp_option ( struct dhcp_option_block *options, unsigned int tag );
extern struct dhcp_option * find_global_dhcp_option ( unsigned int tag );
extern void register_dhcp_options ( struct dhcp_option_block *options );
extern void unregister_dhcp_options ( struct dhcp_option_block *options );
extern struct dhcp_option_block * alloc_dhcp_options ( size_t max_len );
extern void free_dhcp_options ( struct dhcp_option_block *options );
extern struct dhcp_option *
set_dhcp_option ( struct dhcp_option_block *options, unsigned int tag,
const void *data, size_t len );
/**
* Find DHCP numerical option, and return its value
*
* @v tag DHCP option tag to search for
* @v options DHCP options block
* @v tag DHCP option tag to search for
* @ret value Numerical value of the option, or 0 if not found
*
* This function exists merely as a notational shorthand for a call to
@@ -103,8 +134,37 @@ extern struct dhcp_option * find_dhcp_option ( unsigned int tag,
* check that find_dhcp_option() returns a non-NULL value.
*/
static inline unsigned long
find_dhcp_num_option ( unsigned int tag, struct dhcp_option_block *options ) {
return dhcp_num_option ( find_dhcp_option ( tag, options ) );
find_dhcp_num_option ( struct dhcp_option_block *options, unsigned int tag ) {
return dhcp_num_option ( find_dhcp_option ( options, tag ) );
}
/**
* Find DHCP numerical option, and return its value
*
* @v tag DHCP option tag to search for
* @ret value Numerical value of the option, or 0 if not found
*
* This function exists merely as a notational shorthand for a call to
* find_global_dhcp_option() followed by a call to dhcp_num_option().
* It is not possible to distinguish between the cases "option not
* found" and "option has a value of zero" using this function; if
* this matters to you then issue the two constituent calls directly
* and check that find_global_dhcp_option() returns a non-NULL value.
*/
static inline unsigned long
find_global_dhcp_num_option ( unsigned int tag ) {
return dhcp_num_option ( find_global_dhcp_option ( tag ) );
}
/**
* Delete DHCP option
*
* @v options DHCP options block
* @v tag DHCP option tag
*/
static inline void delete_dhcp_option ( struct dhcp_option_block *options,
unsigned int tag ) {
set_dhcp_option ( options, tag, NULL, 0 );
}
#endif /* _GPXE_DHCP_H */