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Allow for calling find_dhcp_option() with "options" set to NULL, in order 

to search through all registered option blocks.

Move some static inlines that are likely to be used frequently into
dhcpopts.c as normal functions, to save space.
pull/1/head
Michael Brown 2006-07-19 11:05:38 +00:00
parent 7ab29b0bfe
commit e40ebb67de
2 changed files with 103 additions and 70 deletions
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55
src/include/gpxe/dhcp.h
View File

@ -287,7 +287,6 @@ struct dhcp_session {
extern unsigned long dhcp_num_option ( struct dhcp_option *option ); extern unsigned long dhcp_num_option ( struct dhcp_option *option );
extern struct dhcp_option * extern struct dhcp_option *
find_dhcp_option ( struct dhcp_option_block *options, unsigned int tag ); 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 register_dhcp_options ( struct dhcp_option_block *options );
extern void unregister_dhcp_options ( struct dhcp_option_block *options ); extern void unregister_dhcp_options ( struct dhcp_option_block *options );
extern void init_dhcp_options ( struct dhcp_option_block *options, extern void init_dhcp_options ( struct dhcp_option_block *options,
@ -297,53 +296,11 @@ extern void free_dhcp_options ( struct dhcp_option_block *options );
extern struct dhcp_option * extern struct dhcp_option *
set_dhcp_option ( struct dhcp_option_block *options, unsigned int tag, set_dhcp_option ( struct dhcp_option_block *options, unsigned int tag,
const void *data, size_t len ); const void *data, size_t len );
extern struct dhcp_option * find_global_dhcp_option ( unsigned int tag );
/** extern unsigned long find_dhcp_num_option ( struct dhcp_option_block *options,
* Find DHCP numerical option, and return its value unsigned int tag );
* extern unsigned long find_global_dhcp_num_option ( unsigned int tag );
* @v options DHCP options block extern void delete_dhcp_option ( struct dhcp_option_block *options,
* @v tag DHCP option tag to search for unsigned int tag );
* @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_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_dhcp_option() returns a non-NULL value.
*/
static inline unsigned long
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 */ #endif /* _GPXE_DHCP_H */

118
src/net/dhcpopts.c
View File

@ -118,19 +118,25 @@ static inline unsigned int dhcp_any_option_len ( struct dhcp_option *option ) {
* *
* @v options DHCP options block * @v options DHCP options block
* @v tag DHCP option tag to search for * @v tag DHCP option tag to search for
* @ret encapsulator Encapsulating DHCP option
* @ret option DHCP option, or NULL if not found * @ret option DHCP option, or NULL if not found
* *
* Searches for the DHCP option matching the specified tag within the * Searches for the DHCP option matching the specified tag within the
* block of data. Encapsulated options may be searched for by using * DHCP option block. Encapsulated options may be searched for by
* DHCP_ENCAP_OPT() to construct the tag value. * using DHCP_ENCAP_OPT() to construct the tag value.
*
* If the option is encapsulated, and @c encapsulator is non-NULL, it
* will be filled in with a pointer to the encapsulating option.
* *
* This routine is designed to be paranoid. It does not assume that * This routine is designed to be paranoid. It does not assume that
* the option data is well-formatted, and so must guard against flaws * the option data is well-formatted, and so must guard against flaws
* such as options missing a @c DHCP_END terminator, or options whose * such as options missing a @c DHCP_END terminator, or options whose
* length would take them beyond the end of the data block. * length would take them beyond the end of the data block.
*/ */
struct dhcp_option * find_dhcp_option ( struct dhcp_option_block *options, static struct dhcp_option *
unsigned int tag ) { find_dhcp_option_with_encap ( struct dhcp_option_block *options,
unsigned int tag,
struct dhcp_option **encapsulator ) {
unsigned int original_tag __attribute__ (( unused )) = tag; unsigned int original_tag __attribute__ (( unused )) = tag;
struct dhcp_option *option = options->data; struct dhcp_option *option = options->data;
ssize_t remaining = options->len; ssize_t remaining = options->len;
@ -157,6 +163,8 @@ struct dhcp_option * find_dhcp_option ( struct dhcp_option_block *options,
/* Check for start of matching encapsulation block */ /* Check for start of matching encapsulation block */
if ( DHCP_IS_ENCAP_OPT ( tag ) && if ( DHCP_IS_ENCAP_OPT ( tag ) &&
( option->tag == DHCP_ENCAPSULATOR ( tag ) ) ) { ( option->tag == DHCP_ENCAPSULATOR ( tag ) ) ) {
if ( encapsulator )
*encapsulator = option;
/* Continue search within encapsulated option block */ /* Continue search within encapsulated option block */
tag = DHCP_ENCAPSULATED ( tag ); tag = DHCP_ENCAPSULATED ( tag );
remaining = option->len; remaining = option->len;
@ -169,30 +177,36 @@ struct dhcp_option * find_dhcp_option ( struct dhcp_option_block *options,
} }
/** /**
* Find DHCP option within all registered DHCP options blocks * Find DHCP option within DHCP options block
* *
* @v options DHCP options block, or NULL
* @v tag DHCP option tag to search for * @v tag DHCP option tag to search for
* @ret option DHCP option, or NULL if not found * @ret option DHCP option, or NULL if not found
* *
* Searches within all registered DHCP option blocks for the specified * Searches for the DHCP option matching the specified tag within the
* tag. Encapsulated options may be searched for by using * DHCP option block. Encapsulated options may be searched for by
* DHCP_ENCAP_OPT() to construct the tag value. * using DHCP_ENCAP_OPT() to construct the tag value.
* *
* Where multiple option blocks contain the same DHCP option, the * If @c options is NULL, all registered option blocks will be
* option from the highest-priority block will be returned. (Priority * searched. Where multiple option blocks contain the same DHCP
* of an options block is determined by the value of the @c * option, the option from the highest-priority block will be
* DHCP_EB_PRIORITY option within the block, if present; the default * returned. (Priority of an options block is determined by the value
* priority is zero). * of the @c DHCP_EB_PRIORITY option within the block, if present; the
* default priority is zero).
*/ */
struct dhcp_option * find_global_dhcp_option ( unsigned int tag ) { struct dhcp_option * find_dhcp_option ( struct dhcp_option_block *options,
struct dhcp_option_block *options; unsigned int tag ) {
struct dhcp_option *option; struct dhcp_option *option;
list_for_each_entry ( options, &option_blocks, list ) { if ( options ) {
if ( ( option = find_dhcp_option ( options, tag ) ) ) return find_dhcp_option_with_encap ( options, tag, NULL );
return option; } else {
list_for_each_entry ( options, &option_blocks, list ) {
if ( ( option = find_dhcp_option ( options, tag ) ) )
return option;
}
return NULL;
} }
return NULL;
} }
/** /**
@ -348,7 +362,7 @@ struct dhcp_option * set_dhcp_option ( struct dhcp_option_block *options,
size_t new_len = ( len ? ( len + DHCP_OPTION_HEADER_LEN ) : 0 ); size_t new_len = ( len ? ( len + DHCP_OPTION_HEADER_LEN ) : 0 );
/* Find old instance of this option, if any */ /* Find old instance of this option, if any */
option = find_dhcp_option ( options, tag ); option = find_dhcp_option_with_encap ( options, tag, &encapsulator );
if ( option ) { if ( option ) {
old_len = dhcp_option_len ( option ); old_len = dhcp_option_len ( option );
DBG ( "Resizing DHCP option %s from length %d to %d\n", DBG ( "Resizing DHCP option %s from length %d to %d\n",
@ -361,7 +375,6 @@ struct dhcp_option * set_dhcp_option ( struct dhcp_option_block *options,
/* Ensure that encapsulator exists, if required */ /* Ensure that encapsulator exists, if required */
if ( DHCP_IS_ENCAP_OPT ( tag ) ) { if ( DHCP_IS_ENCAP_OPT ( tag ) ) {
encapsulator = find_dhcp_option ( options, encap_tag );
if ( ! encapsulator ) if ( ! encapsulator )
encapsulator = set_dhcp_option ( options, encap_tag, encapsulator = set_dhcp_option ( options, encap_tag,
empty_encapsulator, empty_encapsulator,
@ -393,3 +406,66 @@ struct dhcp_option * set_dhcp_option ( struct dhcp_option_block *options,
return option; return option;
} }
/**
* Find DHCP option within all registered DHCP options blocks
*
* @v tag DHCP option tag to search for
* @ret option DHCP option, or NULL if not found
*
* This function exists merely as a notational shorthand for
* find_dhcp_option() with @c options set to NULL.
*/
struct dhcp_option * find_global_dhcp_option ( unsigned int tag ) {
return find_dhcp_option ( NULL, tag );
}
/**
* Find DHCP numerical option, and return its value
*
* @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
* find_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_dhcp_option() returns a non-NULL value.
*/
unsigned long 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.
*/
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
*
* This function exists merely as a notational shorthand for a call to
* set_dhcp_option() with @c len set to zero.
*/
void delete_dhcp_option ( struct dhcp_option_block *options,
unsigned int tag ) {
set_dhcp_option ( options, tag, NULL, 0 );
}