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[Settings] Migrate DHCP and NVO code to the new settings API (untested)

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This commit is contained in:
Michael Brown
2008-03-21 22:15:31 +00:00
parent bb32b8999c
commit 8afb36c3bc
16 changed files with 966 additions and 936 deletions
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468
src/net/dhcpopts.c
View File

@@ -1,5 +1,5 @@
/*
* Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
* Copyright (C) 2008 Michael Brown <mbrown@fensystems.co.uk>.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
@@ -19,14 +19,10 @@
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>
#include <byteswap.h>
#include <errno.h>
#include <string.h>
#include <assert.h>
#include <gpxe/list.h>
#include <gpxe/in.h>
#include <gpxe/uri.h>
#include <gpxe/dhcp.h>
#include <gpxe/dhcpopts.h>
/** @file
*
@@ -34,9 +30,6 @@
*
*/
/** List of registered DHCP option blocks */
LIST_HEAD ( dhcp_option_blocks );
/**
* Obtain printable version of a DHCP option tag
*
@@ -58,47 +51,28 @@ static inline char * dhcp_tag_name ( unsigned int tag ) {
}
/**
* Obtain value of a numerical DHCP option
* Get pointer to DHCP option
*
* @v option DHCP option, or NULL
* @ret value Numerical value of the option, or 0
*
* Parses the numerical value from a DHCP option, if present. It is
* permitted to call dhcp_num_option() with @c option set to NULL; in
* this case 0 will be returned.
*
* The caller does not specify the size of the DHCP option data; this
* is implied by the length field stored within the DHCP option
* itself.
* @v options DHCP options block
* @v offset Offset within options block
* @ret option DHCP option
*/
unsigned long dhcp_num_option ( struct dhcp_option *option ) {
unsigned long value = 0;
uint8_t *data;
if ( option ) {
/* This is actually smaller code than using htons()
* etc., and will also cope well with malformed
* options (such as zero-length options).
*/
for ( data = option->data.bytes ;
data < ( option->data.bytes + option->len ) ; data++ )
value = ( ( value << 8 ) | *data );
}
return value;
static inline __attribute__ (( always_inline )) struct dhcp_option *
dhcp_option ( struct dhcp_options *options, unsigned int offset ) {
return ( ( struct dhcp_option * ) ( options->data + offset ) );
}
/**
* Calculate length of a normal DHCP option
* Get offset of a DHCP option
*
* @v options DHCP options block
* @v option DHCP option
* @ret len Length (including tag and length field)
*
* @c option may not be a @c DHCP_PAD or @c DHCP_END option.
* @ret offset Offset within options block
*/
static inline unsigned int dhcp_option_len ( struct dhcp_option *option ) {
assert ( option->tag != DHCP_PAD );
assert ( option->tag != DHCP_END );
return ( option->len + DHCP_OPTION_HEADER_LEN );
static inline __attribute__ (( always_inline )) int
dhcp_option_offset ( struct dhcp_options *options,
struct dhcp_option *option ) {
return ( ( ( void * ) option ) - options->data );
}
/**
@@ -107,11 +81,11 @@ static inline unsigned int dhcp_option_len ( struct dhcp_option *option ) {
* @v option DHCP option
* @ret len Length (including tag and length field)
*/
static inline unsigned int dhcp_any_option_len ( struct dhcp_option *option ) {
static unsigned int dhcp_option_len ( struct dhcp_option *option ) {
if ( ( option->tag == DHCP_END ) || ( option->tag == DHCP_PAD ) ) {
return 1;
} else {
return dhcp_option_len ( option );
return ( option->len + DHCP_OPTION_HEADER_LEN );
}
}
@@ -120,27 +94,27 @@ static inline unsigned int dhcp_any_option_len ( struct dhcp_option *option ) {
*
* @v options DHCP options block
* @v tag DHCP option tag to search for
* @ret encapsulator Encapsulating DHCP option
* @ret option DHCP option, or NULL if not found
* @ret encap_offset Offset of encapsulating DHCP option
* @ret offset Offset of DHCP option, or negative error
*
* Searches for the DHCP option matching the specified tag within the
* DHCP option block. Encapsulated options may be searched for by
* 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.
* will be filled in with the offset of the encapsulating option.
*
* This routine is designed to be paranoid. It does not assume that
* the option data is well-formatted, and so must guard against flaws
* such as options missing a @c DHCP_END terminator, or options whose
* length would take them beyond the end of the data block.
*/
static struct dhcp_option *
find_dhcp_option_with_encap ( struct dhcp_option_block *options,
unsigned int tag,
struct dhcp_option **encapsulator ) {
static int find_dhcp_option_with_encap ( struct dhcp_options *options,
unsigned int tag,
int *encap_offset ) {
unsigned int original_tag __attribute__ (( unused )) = tag;
struct dhcp_option *option = options->data;
struct dhcp_option *option;
int offset = 0;
ssize_t remaining = options->len;
unsigned int option_len;
@@ -149,16 +123,17 @@ find_dhcp_option_with_encap ( struct dhcp_option_block *options,
* if the length is malformed (i.e. takes us beyond
* the end of the data block).
*/
option_len = dhcp_any_option_len ( option );
option = dhcp_option ( options, offset );
option_len = dhcp_option_len ( option );
remaining -= option_len;
if ( remaining < 0 )
break;
/* Check for matching tag */
if ( option->tag == tag ) {
DBG ( "Found DHCP option %s (length %d) in block %p\n",
dhcp_tag_name ( original_tag ), option->len,
options );
return option;
DBGC ( options, "DHCPOPT %p found %s (length %d)\n",
options, dhcp_tag_name ( original_tag ),
option_len );
return offset;
}
/* Check for explicit end marker */
if ( option->tag == DHCP_END )
@@ -166,168 +141,74 @@ find_dhcp_option_with_encap ( struct dhcp_option_block *options,
/* Check for start of matching encapsulation block */
if ( DHCP_IS_ENCAP_OPT ( tag ) &&
( option->tag == DHCP_ENCAPSULATOR ( tag ) ) ) {
if ( encapsulator )
*encapsulator = option;
if ( encap_offset )
*encap_offset = offset;
/* Continue search within encapsulated option block */
tag = DHCP_ENCAPSULATED ( tag );
remaining = option->len;
option = ( void * ) &option->data;
remaining = option_len;
offset += DHCP_OPTION_HEADER_LEN;
continue;
}
option = ( ( ( void * ) option ) + option_len );
offset += option_len;
}
return NULL;
}
/**
* Find DHCP option within DHCP options block
*
* @v options DHCP options block, or NULL
* @v tag DHCP option tag to search for
* @ret option DHCP option, or NULL if not found
*
* Searches for the DHCP option matching the specified tag within the
* DHCP option block. Encapsulated options may be searched for by
* using DHCP_ENCAP_OPT() to construct the tag value.
*
* If @c options is NULL, all registered option blocks will be
* searched. Where multiple option blocks contain the same DHCP
* option, the option from the highest-priority block will be
* returned. (Priority of an options block is determined by the value
* of the @c DHCP_EB_PRIORITY option within the block, if present; the
* default priority is zero).
*/
struct dhcp_option * find_dhcp_option ( struct dhcp_option_block *options,
unsigned int tag ) {
struct dhcp_option *option;
if ( options ) {
return find_dhcp_option_with_encap ( options, tag, NULL );
} else {
list_for_each_entry ( options, &dhcp_option_blocks, list ) {
if ( ( option = find_dhcp_option ( options, tag ) ) )
return option;
}
return NULL;
}
}
/**
* Register DHCP option block
*
* @v options DHCP option block
*
* Register a block of DHCP options.
*/
void register_dhcp_options ( struct dhcp_option_block *options ) {
struct dhcp_option_block *existing;
/* Determine priority of new block */
options->priority = find_dhcp_num_option ( options, DHCP_EB_PRIORITY );
DBG ( "Registering DHCP options block %p with priority %d\n",
options, options->priority );
/* Insert after any existing blocks which have a higher priority */
list_for_each_entry ( existing, &dhcp_option_blocks, list ) {
if ( options->priority > existing->priority )
break;
}
dhcpopt_get ( options );
list_add_tail ( &options->list, &existing->list );
}
/**
* Unregister DHCP option block
*
* @v options DHCP option block
*/
void unregister_dhcp_options ( struct dhcp_option_block *options ) {
list_del ( &options->list );
dhcpopt_put ( options );
}
/**
* Initialise empty block of DHCP options
*
* @v options Uninitialised DHCP option block
* @v data Memory for DHCP option data
* @v max_len Length of memory for DHCP option data
*
* Populates the DHCP option data with a single @c DHCP_END option and
* fills in the fields of the @c dhcp_option_block structure.
*/
void init_dhcp_options ( struct dhcp_option_block *options,
void *data, size_t max_len ) {
struct dhcp_option *option;
options->data = data;
options->max_len = max_len;
option = options->data;
option->tag = DHCP_END;
options->len = 1;
DBG ( "DHCP options block %p initialised (data %p max_len %#zx)\n",
options, options->data, options->max_len );
}
/**
* Allocate space for a block of DHCP options
*
* @v max_len Maximum length of option block
* @ret options DHCP option block, or NULL
*
* Creates a new DHCP option block and populates it with an empty
* options list. This call does not register the options block.
*/
struct dhcp_option_block * alloc_dhcp_options ( size_t max_len ) {
struct dhcp_option_block *options;
options = malloc ( sizeof ( *options ) + max_len );
if ( options ) {
init_dhcp_options ( options,
( (void *) options + sizeof ( *options ) ),
max_len );
}
return options;
return -ENOENT;
}
/**
* Resize a DHCP option
*
* @v options DHCP option block
* @v option DHCP option to resize
* @v encapsulator Encapsulating option (or NULL)
* @v offset Offset of option to resize
* @v encap_offset Offset of encapsulating offset (or -ve for none)
* @v old_len Old length (including header)
* @v new_len New length (including header)
* @v can_realloc Can reallocate options data if necessary
* @ret rc Return status code
*/
static int resize_dhcp_option ( struct dhcp_option_block *options,
struct dhcp_option *option,
struct dhcp_option *encapsulator,
size_t old_len, size_t new_len ) {
void *source = ( ( ( void * ) option ) + old_len );
void *dest = ( ( ( void * ) option ) + new_len );
void *end = ( options->data + options->max_len );
static int resize_dhcp_option ( struct dhcp_options *options,
int offset, int encap_offset,
size_t old_len, size_t new_len,
int can_realloc ) {
struct dhcp_option *encapsulator;
struct dhcp_option *option;
ssize_t delta = ( new_len - old_len );
size_t new_options_len;
size_t new_encapsulator_len;
void *new_data;
void *source;
void *dest;
void *end;
/* Check for sufficient space, and update length fields */
if ( new_len > DHCP_MAX_LEN )
return -ENOMEM;
return -ENOSPC;
new_options_len = ( options->len + delta );
if ( new_options_len > options->max_len )
return -ENOMEM;
if ( encapsulator ) {
if ( new_options_len > options->max_len ) {
/* Reallocate options block if allowed to do so. */
if ( can_realloc ) {
new_data = realloc ( options->data, new_options_len );
if ( ! new_data )
return -ENOMEM;
options->data = new_data;
options->max_len = new_options_len;
} else {
return -ENOMEM;
}
}
if ( encap_offset >= 0 ) {
encapsulator = dhcp_option ( options, encap_offset );
new_encapsulator_len = ( encapsulator->len + delta );
if ( new_encapsulator_len > DHCP_MAX_LEN )
return -ENOMEM;
return -ENOSPC;
encapsulator->len = new_encapsulator_len;
}
options->len = new_options_len;
/* Move remainder of option data */
option = dhcp_option ( options, offset );
source = ( ( ( void * ) option ) + old_len );
dest = ( ( ( void * ) option ) + new_len );
end = ( options->data + options->max_len );
memmove ( dest, source, ( end - dest ) );
return 0;
@@ -340,7 +221,8 @@ static int resize_dhcp_option ( struct dhcp_option_block *options,
* @v tag DHCP option tag
* @v data New value for DHCP option
* @v len Length of value, in bytes
* @ret option DHCP option, or NULL
* @v can_realloc Can reallocate options data if necessary
* @ret offset Offset of DHCP option, or negative error
*
* Sets the value of a DHCP option within the options block. The
* option may or may not already exist. Encapsulators will be created
@@ -350,97 +232,183 @@ static int resize_dhcp_option ( struct dhcp_option_block *options,
* If it does fail, and the option existed previously, the option will
* be left with its original value.
*/
struct dhcp_option * set_dhcp_option ( struct dhcp_option_block *options,
unsigned int tag,
const void *data, size_t len ) {
static int set_dhcp_option ( struct dhcp_options *options, unsigned int tag,
const void *data, size_t len,
int can_realloc ) {
static const uint8_t empty_encapsulator[] = { DHCP_END };
int offset;
int encap_offset = -1;
int creation_offset = 0;
struct dhcp_option *option;
void *insertion_point;
struct dhcp_option *encapsulator = NULL;
unsigned int encap_tag = DHCP_ENCAPSULATOR ( tag );
size_t old_len = 0;
size_t new_len = ( len ? ( len + DHCP_OPTION_HEADER_LEN ) : 0 );
/* Return NULL if no options block specified */
if ( ! options )
return NULL;
int rc;
/* Find old instance of this option, if any */
option = find_dhcp_option_with_encap ( options, tag, &encapsulator );
if ( option ) {
old_len = dhcp_option_len ( option );
DBG ( "Resizing DHCP option %s from length %d to %zd in block "
"%p\n", dhcp_tag_name (tag), option->len, len, options );
offset = find_dhcp_option_with_encap ( options, tag, &encap_offset );
if ( offset >= 0 ) {
old_len = dhcp_option_len ( dhcp_option ( options, offset ) );
DBGC ( options, "DHCPOPT %p resizing %s from %zd to %zd\n",
options, dhcp_tag_name ( tag ), old_len, new_len );
} else {
old_len = 0;
DBG ( "Creating DHCP option %s (length %zd) in block %p\n",
dhcp_tag_name ( tag ), len, options );
DBGC ( options, "DHCPOPT %p creating %s (length %zd)\n",
options, dhcp_tag_name ( tag ), len );
}
/* Ensure that encapsulator exists, if required */
insertion_point = options->data;
if ( DHCP_IS_ENCAP_OPT ( tag ) ) {
if ( ! encapsulator )
encapsulator = set_dhcp_option ( options, encap_tag,
empty_encapsulator,
sizeof ( empty_encapsulator) );
if ( ! encapsulator )
return NULL;
insertion_point = &encapsulator->data;
if ( encap_tag ) {
if ( encap_offset < 0 )
encap_offset = set_dhcp_option ( options, encap_tag,
empty_encapsulator, 1,
can_realloc );
if ( encap_offset < 0 )
return encap_offset;
creation_offset = ( encap_offset + DHCP_OPTION_HEADER_LEN );
}
/* Create new option if necessary */
if ( ! option )
option = insertion_point;
if ( offset < 0 )
offset = creation_offset;
/* Resize option to fit new data */
if ( resize_dhcp_option ( options, option, encapsulator,
old_len, new_len ) != 0 )
return NULL;
if ( ( rc = resize_dhcp_option ( options, offset, encap_offset,
old_len, new_len,
can_realloc ) ) != 0 )
return rc;
/* Copy new data into option, if applicable */
if ( len ) {
option = dhcp_option ( options, offset );
option->tag = tag;
option->len = len;
memcpy ( &option->data, data, len );
}
/* Delete encapsulator if there's nothing else left in it */
if ( encapsulator && ( encapsulator->len <= 1 ) )
set_dhcp_option ( options, encap_tag, NULL, 0 );
if ( encap_offset >= 0 ) {
option = dhcp_option ( options, encap_offset );
if ( option->len <= 1 )
set_dhcp_option ( options, encap_tag, NULL, 0, 0 );
}
return option;
return offset;
}
/**
* Find DHCP numerical option, and return its value
* Store value of DHCP option setting
*
* @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.
* @v options DHCP option block
* @v tag Setting tag number
* @v data Setting data, or NULL to clear setting
* @v len Length of setting data
* @ret rc Return status code
*/
unsigned long find_dhcp_num_option ( struct dhcp_option_block *options,
unsigned int tag ) {
return dhcp_num_option ( find_dhcp_option ( options, tag ) );
int dhcpopt_store ( struct dhcp_options *options, unsigned int tag,
const void *data, size_t len ) {
int offset;
offset = set_dhcp_option ( options, tag, data, len, 0 );
if ( offset < 0 )
return offset;
return 0;
}
/**
* Delete DHCP option
* Store value of DHCP option setting, extending options block if necessary
*
* @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.
* @v options DHCP option block
* @v tag Setting tag number
* @v data Setting data, or NULL to clear setting
* @v len Length of setting data
* @ret rc Return status code
*/
void delete_dhcp_option ( struct dhcp_option_block *options,
unsigned int tag ) {
set_dhcp_option ( options, tag, NULL, 0 );
int dhcpopt_extensible_store ( struct dhcp_options *options, unsigned int tag,
const void *data, size_t len ) {
int offset;
offset = set_dhcp_option ( options, tag, data, len, 1 );
if ( offset < 0 )
return offset;
return 0;
}
/**
* Fetch value of DHCP option setting
*
* @v options DHCP option block
* @v tag Setting tag number
* @v data Buffer to fill with setting data
* @v len Length of buffer
* @ret len Length of setting data, or negative error
*/
int dhcpopt_fetch ( struct dhcp_options *options, unsigned int tag,
void *data, size_t len ) {
int offset;
struct dhcp_option *option;
size_t option_len;
offset = find_dhcp_option_with_encap ( options, tag, NULL );
if ( offset < 0 )
return offset;
option = dhcp_option ( options, offset );
option_len = dhcp_option_len ( option );
if ( len > option_len )
len = option_len;
memcpy ( data, option->data, len );
return option_len;
}
/**
* Recalculate length of DHCP options block
*
* @v options Uninitialised DHCP option block
*
* The "used length" field will be updated based on scanning through
* the block to find the end of the options.
*/
static void dhcpopt_update_len ( struct dhcp_options *options ) {
struct dhcp_option *option;
int offset = 0;
ssize_t remaining = options->max_len;
unsigned int option_len;
/* Find last non-pad option */
options->len = 0;
while ( remaining ) {
option = dhcp_option ( options, offset );
option_len = dhcp_option_len ( option );
remaining -= option_len;
if ( remaining < 0 )
break;
offset += option_len;
if ( option->tag != DHCP_PAD )
options->len = offset;
}
}
/**
* Initialise prepopulated block of DHCP options
*
* @v options Uninitialised DHCP option block
* @v data Memory for DHCP option data
* @v max_len Length of memory for DHCP option data
*
* The memory content must already be filled with valid DHCP options.
* A zeroed block counts as a block of valid DHCP options.
*/
void dhcpopt_init ( struct dhcp_options *options, void *data,
size_t max_len ) {
/* Fill in fields */
options->data = data;
options->max_len = max_len;
/* Update length */
dhcpopt_update_len ( options );
DBGC ( options, "DHCPOPT %p created (data %p len %#zx max_len %#zx)\n",
options, options->data, options->len, options->max_len );
}

186
src/net/dhcppkt.c Normal file
View File

@@ -0,0 +1,186 @@
/*
* Copyright (C) 2008 Michael Brown <mbrown@fensystems.co.uk>.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <gpxe/netdevice.h>
#include <gpxe/dhcp.h>
#include <gpxe/dhcpopts.h>
#include <gpxe/dhcppkt.h>
/** @file
*
* DHCP packets
*
*/
/** A dedicated field within a DHCP packet */
struct dhcp_packet_field {
/** Settings tag number */
unsigned int tag;
/** Offset within DHCP packet */
uint16_t offset;
/** Length of field */
uint16_t len;
};
/** Declare a dedicated field within a DHCP packet
*
* @v _tag Settings tag number
* @v _field Field name
*/
#define DHCP_PACKET_FIELD( _tag, _field ) { \
.tag = (_tag), \
.offset = offsetof ( struct dhcphdr, _field ), \
.len = sizeof ( ( ( struct dhcphdr * ) 0 )->_field ), \
}
/** Dedicated fields within a DHCP packet */
static struct dhcp_packet_field dhcp_packet_fields[] = {
DHCP_PACKET_FIELD ( DHCP_EB_YIADDR, yiaddr ),
DHCP_PACKET_FIELD ( DHCP_EB_SIADDR, siaddr ),
DHCP_PACKET_FIELD ( DHCP_TFTP_SERVER_NAME, sname ),
DHCP_PACKET_FIELD ( DHCP_BOOTFILE_NAME, file ),
};
/**
* Get address of a DHCP packet field
*
* @v dhcphdr DHCP packet header
* @v field DHCP packet field
* @ret data Packet field data
*/
static inline void * dhcp_packet_field ( struct dhcphdr *dhcphdr,
struct dhcp_packet_field *field ) {
return ( ( ( void * ) dhcphdr ) + field->offset );
}
/**
* Find DHCP packet field corresponding to settings tag number
*
* @v tag Settings tag number
* @ret field DHCP packet field, or NULL
*/
static struct dhcp_packet_field *
find_dhcp_packet_field ( unsigned int tag ) {
struct dhcp_packet_field *field;
unsigned int i;
for ( i = 0 ; i < ( sizeof ( dhcp_packet_fields ) /
sizeof ( dhcp_packet_fields[0] ) ) ; i++ ) {
field = &dhcp_packet_fields[i];
if ( field->tag == tag )
return field;
}
return NULL;
}
/**
* Store value of DHCP packet setting
*
* @v settings Settings block
* @v tag Setting tag number
* @v data Setting data, or NULL to clear setting
* @v len Length of setting data
* @ret rc Return status code
*/
static int dhcppkt_store ( struct settings *settings, unsigned int tag,
const void *data, size_t len ) {
struct dhcp_packet *dhcppkt =
container_of ( settings, struct dhcp_packet, settings );
struct dhcp_packet_field *field;
int rc;
/* If this is a special field, fill it in */
if ( ( field = find_dhcp_packet_field ( tag ) ) != NULL ) {
if ( len > field->len )
return -ENOSPC;
memcpy ( dhcp_packet_field ( dhcppkt->dhcphdr, field ),
data, len );
return 0;
}
/* Otherwise, use the generic options block */
rc = dhcpopt_store ( &dhcppkt->options, tag, data, len );
/* Update our used-length field */
dhcppkt->len = ( offsetof ( struct dhcphdr, options ) +
dhcppkt->options.len );
return rc;
}
/**
* Fetch value of DHCP packet setting
*
* @v settings Settings block
* @v tag Setting tag number
* @v data Buffer to fill with setting data
* @v len Length of buffer
* @ret len Length of setting data, or negative error
*/
static int dhcppkt_fetch ( struct settings *settings, unsigned int tag,
void *data, size_t len ) {
struct dhcp_packet *dhcppkt =
container_of ( settings, struct dhcp_packet, settings );
struct dhcp_packet_field *field;
/* If this is a special field, return it */
if ( ( field = find_dhcp_packet_field ( tag ) ) != NULL ) {
if ( len > field->len )
len = field->len;
memcpy ( data,
dhcp_packet_field ( dhcppkt->dhcphdr, field ), len );
return field->len;
}
/* Otherwise, use the generic options block */
return dhcpopt_fetch ( &dhcppkt->options, tag, data, len );
}
/** DHCP settings operations */
static struct settings_operations dhcppkt_settings_operations = {
.store = dhcppkt_store,
.fetch = dhcppkt_fetch,
};
/**
* Initialise prepopulated DHCP packet
*
* @v dhcppkt Uninitialised DHCP packet
* @v refcnt Reference counter of containing object, or NULL
* @v data Memory for DHCP packet data
* @v max_len Length of memory for DHCP packet data
*
* The memory content must already be filled with valid DHCP options.
* A zeroed block counts as a block of valid DHCP options.
*/
void dhcppkt_init ( struct dhcp_packet *dhcppkt, struct refcnt *refcnt,
void *data, size_t len ) {
dhcppkt->dhcphdr = data;
dhcppkt->max_len = len;
dhcpopt_init ( &dhcppkt->options, &dhcppkt->dhcphdr->options,
( len - offsetof ( struct dhcphdr, options ) ) );
dhcppkt->len = ( offsetof ( struct dhcphdr, options ) +
dhcppkt->options.len );
settings_init ( &dhcppkt->settings, &dhcppkt_settings_operations,
refcnt, "dhcp" );
}

634
src/net/udp/dhcp.c
View File

@@ -34,6 +34,10 @@
#include <gpxe/uuid.h>
#include <gpxe/dhcp.h>
#include <gpxe/timer.h>
#include <gpxe/settings.h>
#include <gpxe/dhcp.h>
#include <gpxe/dhcpopts.h>
#include <gpxe/dhcppkt.h>
/** @file
*
@@ -41,7 +45,8 @@
*
*/
/** DHCP operation types
/**
* DHCP operation types
*
* This table maps from DHCP message types (i.e. values of the @c
* DHCP_MESSAGE_TYPE option) to values of the "op" field within a DHCP
@@ -76,6 +81,13 @@ static uint8_t dhcp_request_options_data[] = {
DHCP_END
};
/** Options common to all DHCP requests */
static struct dhcp_options dhcp_request_options = {
.data = dhcp_request_options_data,
.max_len = sizeof ( dhcp_request_options_data ),
.len = sizeof ( dhcp_request_options_data ),
};
/** DHCP feature codes */
static uint8_t dhcp_features[0] __table_start ( uint8_t, dhcp_features );
static uint8_t dhcp_features_end[0] __table_end ( uint8_t, dhcp_features );
@@ -118,197 +130,33 @@ static uint32_t dhcp_xid ( struct net_device *netdev ) {
return xid;
}
/** Options common to all DHCP requests */
static struct dhcp_option_block dhcp_request_options = {
.data = dhcp_request_options_data,
.max_len = sizeof ( dhcp_request_options_data ),
.len = sizeof ( dhcp_request_options_data ),
};
/**
* Set option within DHCP packet
*
* @v dhcppkt DHCP packet
* @v tag DHCP option tag
* @v data New value for DHCP option
* @v len Length of value, in bytes
* @ret rc Return status code
*
* Sets the option within the first available options block within the
* DHCP packet. Option blocks are tried in the order specified by @c
* dhcp_option_block_fill_order.
*
* The magic options @c DHCP_EB_YIADDR and @c DHCP_EB_SIADDR are
* intercepted and inserted into the appropriate fixed fields within
* the DHCP packet. The option @c DHCP_OPTION_OVERLOAD is silently
* ignored, since our DHCP packet assembly method relies on always
* having option overloading in use.
*/
static int set_dhcp_packet_option ( struct dhcp_packet *dhcppkt,
unsigned int tag, const void *data,
size_t len ) {
struct dhcphdr *dhcphdr = dhcppkt->dhcphdr;
struct dhcp_option_block *options = &dhcppkt->options;
struct dhcp_option *option = NULL;
/* Special-case the magic options */
switch ( tag ) {
case DHCP_OPTION_OVERLOAD:
/* Hard-coded in packets we create; always ignore */
return 0;
case DHCP_EB_YIADDR:
memcpy ( &dhcphdr->yiaddr, data, sizeof ( dhcphdr->yiaddr ) );
return 0;
case DHCP_EB_SIADDR:
memcpy ( &dhcphdr->siaddr, data, sizeof ( dhcphdr->siaddr ) );
return 0;
case DHCP_TFTP_SERVER_NAME:
memset ( dhcphdr->sname, 0, sizeof ( dhcphdr->sname ) );
if ( len > sizeof ( dhcphdr->sname ) )
len = sizeof ( dhcphdr->sname );
memcpy ( dhcphdr->sname, data, len );
return 0;
case DHCP_BOOTFILE_NAME:
memset ( dhcphdr->file, 0, sizeof ( dhcphdr->file ) );
if ( len > sizeof ( dhcphdr->file ) )
len = sizeof ( dhcphdr->file );
memcpy ( dhcphdr->file, data, len );
return 0;
default:
/* Continue processing as normal */
break;
}
/* Set option */
option = set_dhcp_option ( options, tag, data, len );
/* Update DHCP packet length */
dhcppkt->len = ( offsetof ( typeof ( *dhcppkt->dhcphdr ), options )
+ dhcppkt->options.len );
return ( option ? 0 : -ENOSPC );
}
/**
* Copy option into DHCP packet
*
* @v dhcppkt DHCP packet
* @v options DHCP option block, or NULL
* @v tag DHCP option tag to search for
* @v new_tag DHCP option tag to use for copied option
* @ret rc Return status code
*
* Copies a single option, if present, from the DHCP options block
* into a DHCP packet. The tag for the option may be changed if
* desired; this is required by other parts of the DHCP code.
*
* @c options may specify a single options block, or be left as NULL
* in order to search for the option within all registered options
* blocks.
*/
static int copy_dhcp_packet_option ( struct dhcp_packet *dhcppkt,
struct dhcp_option_block *options,
unsigned int tag, unsigned int new_tag ) {
struct dhcp_option *option;
int rc;
option = find_dhcp_option ( options, tag );
if ( option ) {
if ( ( rc = set_dhcp_packet_option ( dhcppkt, new_tag,
&option->data,
option->len ) ) != 0 )
return rc;
}
return 0;
}
/**
* Copy options into DHCP packet
*
* @v dhcppkt DHCP packet
* @v options DHCP option block, or NULL
* @v encapsulator Encapsulating option, or zero
* @ret rc Return status code
*
* Copies options with the specified encapsulator from DHCP options
* blocks into a DHCP packet. Most options are copied verbatim.
* Recognised encapsulated options fields are handled as such.
*
* @c options may specify a single options block, or be left as NULL
* in order to copy options from all registered options blocks.
*/
static int copy_dhcp_packet_encap_options ( struct dhcp_packet *dhcppkt,
struct dhcp_option_block *options,
unsigned int encapsulator ) {
unsigned int subtag;
unsigned int tag;
int rc;
for ( subtag = DHCP_MIN_OPTION; subtag <= DHCP_MAX_OPTION; subtag++ ) {
tag = DHCP_ENCAP_OPT ( encapsulator, subtag );
switch ( tag ) {
case DHCP_EB_ENCAP:
case DHCP_VENDOR_ENCAP:
/* Process encapsulated options field */
if ( ( rc = copy_dhcp_packet_encap_options ( dhcppkt,
options,
tag)) !=0)
return rc;
break;
default:
/* Copy option to reassembled packet */
if ( ( rc = copy_dhcp_packet_option ( dhcppkt, options,
tag, tag ) ) !=0)
return rc;
break;
};
}
return 0;
}
/**
* Copy options into DHCP packet
*
* @v dhcppkt DHCP packet
* @v options DHCP option block, or NULL
* @ret rc Return status code
*
* Copies options from DHCP options blocks into a DHCP packet. Most
* options are copied verbatim. Recognised encapsulated options
* fields are handled as such.
*
* @c options may specify a single options block, or be left as NULL
* in order to copy options from all registered options blocks.
*/
static int copy_dhcp_packet_options ( struct dhcp_packet *dhcppkt,
struct dhcp_option_block *options ) {
return copy_dhcp_packet_encap_options ( dhcppkt, options, 0 );
}
/**
* Create a DHCP packet
*
* @v dhcppkt DHCP packet structure to fill in
* @v netdev Network device
* @v msgtype DHCP message type
* @v options Initial options to include (or NULL)
* @v data Buffer for DHCP packet
* @v max_len Size of DHCP packet buffer
* @v dhcppkt DHCP packet structure to fill in
* @ret rc Return status code
*
* Creates a DHCP packet in the specified buffer, and fills out a @c
* dhcp_packet structure that can be passed to
* set_dhcp_packet_option() or copy_dhcp_packet_options().
*/
static int create_dhcp_packet ( struct net_device *netdev, uint8_t msgtype,
void *data, size_t max_len,
struct dhcp_packet *dhcppkt ) {
static int create_dhcp_packet ( struct dhcp_packet *dhcppkt,
struct net_device *netdev, uint8_t msgtype,
struct dhcp_options *options,
void *data, size_t max_len ) {
struct dhcphdr *dhcphdr = data;
size_t options_len;
unsigned int hlen;
int rc;
/* Sanity check */
if ( max_len < sizeof ( *dhcphdr ) )
options_len = ( options ? options->len : 0 );
if ( max_len < ( sizeof ( *dhcphdr ) + options_len ) )
return -ENOSPC;
/* Initialise DHCP packet content */
@@ -327,180 +175,19 @@ static int create_dhcp_packet ( struct net_device *netdev, uint8_t msgtype,
}
dhcphdr->hlen = hlen;
memcpy ( dhcphdr->chaddr, netdev->ll_addr, hlen );
memcpy ( dhcphdr->options, options, options_len );
/* Initialise DHCP packet structure */
dhcppkt->dhcphdr = dhcphdr;
dhcppkt->max_len = max_len;
init_dhcp_options ( &dhcppkt->options, dhcphdr->options,
( max_len -
offsetof ( typeof ( *dhcphdr ), options ) ) );
/* Initialise DHCP packet structure and settings interface */
dhcppkt_init ( dhcppkt, NULL, data, max_len );
/* Set DHCP_MESSAGE_TYPE option */
if ( ( rc = set_dhcp_packet_option ( dhcppkt, DHCP_MESSAGE_TYPE,
&msgtype,
sizeof ( msgtype ) ) ) != 0 )
if ( ( rc = store_setting ( &dhcppkt->settings, DHCP_MESSAGE_TYPE,
&msgtype, sizeof ( msgtype ) ) ) != 0 )
return rc;
return 0;
}
/**
* Calculate used length of a field containing DHCP options
*
* @v data Field containing DHCP options
* @v max_len Field length
* @ret len Used length (excluding the @c DHCP_END tag)
*/
static size_t dhcp_field_len ( const void *data, size_t max_len ) {
struct dhcp_option_block options;
struct dhcp_option *end;
options.data = ( ( void * ) data );
options.len = max_len;
end = find_dhcp_option ( &options, DHCP_END );
return ( end ? ( ( ( void * ) end ) - data ) : 0 );
}
/**
* Merge field containing DHCP options or string into DHCP options block
*
* @v options DHCP option block
* @v data Field containing DHCP options
* @v max_len Field length
* @v tag DHCP option tag, or 0
*
* If @c tag is non-zero (and the field is not empty), the field will
* be treated as a NUL-terminated string representing the value of the
* specified DHCP option. If @c tag is zero, the field will be
* treated as a block of DHCP options, and simply appended to the
* existing options in the option block.
*
* The caller must ensure that there is enough space in the options
* block to perform the merge.
*/
static void merge_dhcp_field ( struct dhcp_option_block *options,
const void *data, size_t max_len,
unsigned int tag ) {
size_t len;
void *dest;
struct dhcp_option *end;
if ( tag ) {
len = strlen ( data );
if ( len )
set_dhcp_option ( options, tag, data, len );
} else {
len = dhcp_field_len ( data, max_len );
dest = ( options->data + options->len - 1 );
memcpy ( dest, data, len );
options->len += len;
end = ( dest + len );
end->tag = DHCP_END;
}
}
/**
* Parse DHCP packet and construct DHCP options block
*
* @v dhcphdr DHCP packet
* @v len Length of DHCP packet
* @ret options DHCP options block, or NULL
*
* Parses a received DHCP packet and canonicalises its contents into a
* single DHCP options block. The "file" and "sname" fields are
* converted into the corresponding DHCP options (@c
* DHCP_BOOTFILE_NAME and @c DHCP_TFTP_SERVER_NAME respectively). If
* these fields are used for option overloading, their options are
* merged in to the options block.
*
* The values of the "yiaddr" and "siaddr" fields will be stored
* within the options block as the magic options @c DHCP_EB_YIADDR and
* @c DHCP_EB_SIADDR.
*
* Note that this call allocates new memory for the constructed DHCP
* options block; it is the responsibility of the caller to eventually
* free this memory.
*/
static struct dhcp_option_block * dhcp_parse ( const struct dhcphdr *dhcphdr,
size_t len ) {
struct dhcp_option_block *options;
size_t options_len;
unsigned int overloading;
/* Sanity check */
if ( len < sizeof ( *dhcphdr ) )
return NULL;
/* Calculate size of resulting concatenated option block:
*
* The "options" field : length of the field minus the DHCP_END tag.
*
* The "file" field : maximum length of the field minus the
* NUL terminator, plus a 2-byte DHCP header or, if used for
* option overloading, the length of the field minus the
* DHCP_END tag.
*
* The "sname" field : as for the "file" field.
*
* 15 bytes for an encapsulated options field to contain the
* value of the "yiaddr" and "siaddr" fields
*
* 1 byte for a final terminating DHCP_END tag.
*/
options_len = ( ( len - offsetof ( typeof ( *dhcphdr ), options ) ) - 1
+ ( sizeof ( dhcphdr->file ) + 1 )
+ ( sizeof ( dhcphdr->sname ) + 1 )
+ 15 /* yiaddr and siaddr */
+ 1 /* DHCP_END tag */ );
/* Allocate empty options block of required size */
options = alloc_dhcp_options ( options_len );
if ( ! options ) {
DBG ( "DHCP could not allocate %zd-byte option block\n",
options_len );
return NULL;
}
/* Merge in "options" field, if this is a DHCP packet */
if ( dhcphdr->magic == htonl ( DHCP_MAGIC_COOKIE ) ) {
merge_dhcp_field ( options, dhcphdr->options,
( len -
offsetof ( typeof (*dhcphdr), options ) ),
0 /* Always contains options */ );
}
/* Identify overloaded fields */
overloading = find_dhcp_num_option ( options, DHCP_OPTION_OVERLOAD );
/* Merge in "file" and "sname" fields */
merge_dhcp_field ( options, dhcphdr->file, sizeof ( dhcphdr->file ),
( ( overloading & DHCP_OPTION_OVERLOAD_FILE ) ?
0 : DHCP_BOOTFILE_NAME ) );
merge_dhcp_field ( options, dhcphdr->sname, sizeof ( dhcphdr->sname ),
( ( overloading & DHCP_OPTION_OVERLOAD_SNAME ) ?
0 : DHCP_TFTP_SERVER_NAME ) );
/* Set magic options for "yiaddr" and "siaddr", if present */
if ( dhcphdr->yiaddr.s_addr ) {
set_dhcp_option ( options, DHCP_EB_YIADDR,
&dhcphdr->yiaddr, sizeof (dhcphdr->yiaddr) );
}
if ( dhcphdr->siaddr.s_addr ) {
set_dhcp_option ( options, DHCP_EB_SIADDR,
&dhcphdr->siaddr, sizeof (dhcphdr->siaddr) );
}
assert ( options->len <= options->max_len );
return options;
}
/****************************************************************************
*
* Whole-packet construction
*
*/
/** DHCP network device descriptor */
struct dhcp_netdev_desc {
/** Bus type ID */
@@ -532,18 +219,18 @@ struct dhcp_client_uuid {
/**
* Create DHCP request
*
* @v dhcppkt DHCP packet structure to fill in
* @v netdev Network device
* @v msgtype DHCP message type
* @v options DHCP server response options, or NULL
* @v offer_settings Settings received in DHCPOFFER, or NULL
* @v data Buffer for DHCP packet
* @v max_len Size of DHCP packet buffer
* @v dhcppkt DHCP packet structure to fill in
* @ret rc Return status code
*/
int create_dhcp_request ( struct net_device *netdev, int msgtype,
struct dhcp_option_block *options,
void *data, size_t max_len,
struct dhcp_packet *dhcppkt ) {
int create_dhcp_request ( struct dhcp_packet *dhcppkt,
struct net_device *netdev, int msgtype,
struct settings *offer_settings,
void *data, size_t max_len ) {
struct device_description *desc = &netdev->dev->desc;
struct dhcp_netdev_desc dhcp_desc;
struct dhcp_client_id client_id;
@@ -553,33 +240,27 @@ int create_dhcp_request ( struct net_device *netdev, int msgtype,
int rc;
/* Create DHCP packet */
if ( ( rc = create_dhcp_packet ( netdev, msgtype, data, max_len,
dhcppkt ) ) != 0 ) {
if ( ( rc = create_dhcp_packet ( dhcppkt, netdev, msgtype,
&dhcp_request_options, data,
max_len ) ) != 0 ) {
DBG ( "DHCP could not create DHCP packet: %s\n",
strerror ( rc ) );
return rc;
}
/* Copy in options common to all requests */
if ( ( rc = copy_dhcp_packet_options ( dhcppkt,
&dhcp_request_options )) !=0 ){
DBG ( "DHCP could not set common DHCP options: %s\n",
strerror ( rc ) );
return rc;
}
/* Copy any required options from previous server repsonse */
if ( options ) {
if ( ( rc = copy_dhcp_packet_option ( dhcppkt, options,
DHCP_SERVER_IDENTIFIER,
DHCP_SERVER_IDENTIFIER ) ) != 0 ) {
if ( offer_settings ) {
if ( ( rc = copy_setting ( &dhcppkt->settings,
DHCP_SERVER_IDENTIFIER,
offer_settings,
DHCP_SERVER_IDENTIFIER ) ) != 0 ) {
DBG ( "DHCP could not set server identifier "
"option: %s\n", strerror ( rc ) );
return rc;
}
if ( ( rc = copy_dhcp_packet_option ( dhcppkt, options,
DHCP_EB_YIADDR,
DHCP_REQUESTED_ADDRESS ) ) != 0 ) {
if ( ( rc = copy_setting ( &dhcppkt->settings, DHCP_EB_YIADDR,
offer_settings,
DHCP_REQUESTED_ADDRESS ) ) != 0 ) {
DBG ( "DHCP could not set requested address "
"option: %s\n", strerror ( rc ) );
return rc;
@@ -588,9 +269,8 @@ int create_dhcp_request ( struct net_device *netdev, int msgtype,
/* Add options to identify the feature list */
dhcp_features_len = ( dhcp_features_end - dhcp_features );
if ( ( rc = set_dhcp_packet_option ( dhcppkt, DHCP_EB_ENCAP,
dhcp_features,
dhcp_features_len ) ) != 0 ) {
if ( ( rc = store_setting ( &dhcppkt->settings, DHCP_EB_ENCAP,
dhcp_features, dhcp_features_len ) ) !=0 ){
DBG ( "DHCP could not set features list option: %s\n",
strerror ( rc ) );
return rc;
@@ -600,9 +280,8 @@ int create_dhcp_request ( struct net_device *netdev, int msgtype,
dhcp_desc.type = desc->bus_type;
dhcp_desc.vendor = htons ( desc->vendor );
dhcp_desc.device = htons ( desc->device );
if ( ( rc = set_dhcp_packet_option ( dhcppkt, DHCP_EB_BUS_ID,
&dhcp_desc,
sizeof ( dhcp_desc ) ) ) != 0 ) {
if ( ( rc = store_setting ( &dhcppkt->settings, DHCP_EB_BUS_ID,
&dhcp_desc, sizeof ( dhcp_desc ) ) ) !=0 ){
DBG ( "DHCP could not set bus ID option: %s\n",
strerror ( rc ) );
return rc;
@@ -615,9 +294,8 @@ int create_dhcp_request ( struct net_device *netdev, int msgtype,
ll_addr_len = netdev->ll_protocol->ll_addr_len;
assert ( ll_addr_len <= sizeof ( client_id.ll_addr ) );
memcpy ( client_id.ll_addr, netdev->ll_addr, ll_addr_len );
if ( ( rc = set_dhcp_packet_option ( dhcppkt, DHCP_CLIENT_ID,
&client_id,
( ll_addr_len + 1 ) ) ) != 0 ) {
if ( ( rc = store_setting ( &dhcppkt->settings, DHCP_CLIENT_ID,
&client_id, ( ll_addr_len + 1 ) ) ) != 0 ){
DBG ( "DHCP could not set client ID: %s\n",
strerror ( rc ) );
return rc;
@@ -626,9 +304,9 @@ int create_dhcp_request ( struct net_device *netdev, int msgtype,
/* Add client UUID, if we have one. Required for PXE. */
client_uuid.type = DHCP_CLIENT_UUID_TYPE;
if ( ( rc = get_uuid ( &client_uuid.uuid ) ) == 0 ) {
if ( ( rc = set_dhcp_packet_option ( dhcppkt,
DHCP_CLIENT_UUID, &client_uuid,
sizeof ( client_uuid ) ) ) != 0 ) {
if ( ( rc = store_setting ( &dhcppkt->settings,
DHCP_CLIENT_UUID, &client_uuid,
sizeof ( client_uuid ) ) ) != 0 ) {
DBG ( "DHCP could not set client UUID: %s\n",
strerror ( rc ) );
return rc;
@@ -641,34 +319,86 @@ int create_dhcp_request ( struct net_device *netdev, int msgtype,
/**
* Create DHCP response
*
* @v dhcppkt DHCP packet structure to fill in
* @v netdev Network device
* @v msgtype DHCP message type
* @v options DHCP options, or NULL
* @v settings Settings to include, or NULL
* @v data Buffer for DHCP packet
* @v max_len Size of DHCP packet buffer
* @v dhcppkt DHCP packet structure to fill in
* @ret rc Return status code
*/
int create_dhcp_response ( struct net_device *netdev, int msgtype,
struct dhcp_option_block *options,
void *data, size_t max_len,
struct dhcp_packet *dhcppkt ) {
int create_dhcp_response ( struct dhcp_packet *dhcppkt,
struct net_device *netdev, int msgtype,
struct settings *settings,
void *data, size_t max_len ) {
int rc;
/* Create packet and copy in options */
if ( ( rc = create_dhcp_packet ( netdev, msgtype, data, max_len,
dhcppkt ) ) != 0 ) {
DBG ( " failed to build packet" );
if ( ( rc = create_dhcp_packet ( dhcppkt, netdev, msgtype, NULL,
data, max_len ) ) != 0 )
return rc;
}
if ( ( rc = copy_dhcp_packet_options ( dhcppkt, options ) ) != 0 ) {
DBG ( " failed to copy options" );
if ( ( rc = copy_settings ( &dhcppkt->settings, settings ) ) != 0 )
return rc;
}
return 0;
}
/****************************************************************************
*
* DHCP packets contained in I/O buffers
*
*/
/** A DHCP packet contained in an I/O buffer */
struct dhcp_iobuf_packet {
/** Reference counter */
struct refcnt refcnt;
/** DHCP packet */
struct dhcp_packet dhcppkt;
/** Containing I/O buffer */
struct io_buffer *iobuf;
};
/**
* Free DHCP packet contained in an I/O buffer
*
* @v refcnt Reference counter
*/
static void dhcpiob_free ( struct refcnt *refcnt ) {
struct dhcp_iobuf_packet *dhcpiob =
container_of ( refcnt, struct dhcp_iobuf_packet, refcnt );
free_iob ( dhcpiob->iobuf );
free ( dhcpiob );
}
/**
* Create DHCP packet from I/O buffer
*
* @v iobuf I/O buffer
* @ret dhcpiob DHCP packet contained in I/O buffer
*
* This function takes ownership of the I/O buffer. Future accesses
* must be via the @c dhcpiob data structure.
*/
static struct dhcp_iobuf_packet * dhcpiob_create ( struct io_buffer *iobuf ) {
struct dhcp_iobuf_packet *dhcpiob;
dhcpiob = zalloc ( sizeof ( *dhcpiob ) );
if ( dhcpiob ) {
dhcpiob->refcnt.free = dhcpiob_free;
dhcpiob->iobuf = iobuf;
dhcppkt_init ( &dhcpiob->dhcppkt, &dhcpiob->refcnt,
iobuf->data, iob_len ( iobuf ) );
}
return dhcpiob;
}
static void dhcpiob_put ( struct dhcp_iobuf_packet *dhcpiob ) {
if ( dhcpiob )
ref_put ( &dhcpiob->refcnt );
}
/****************************************************************************
*
* DHCP to UDP interface
@@ -686,9 +416,6 @@ struct dhcp_session {
/** Network device being configured */
struct net_device *netdev;
/** Option block registration routine */
int ( * register_options ) ( struct net_device *netdev,
struct dhcp_option_block *options );
/** State of the session
*
@@ -696,10 +423,10 @@ struct dhcp_session {
* (e.g. @c DHCPDISCOVER).
*/
int state;
/** Options obtained from DHCP server */
struct dhcp_option_block *options;
/** Options obtained from ProxyDHCP server */
struct dhcp_option_block *proxy_options;
/** Response obtained from DHCP server */
struct dhcp_iobuf_packet *response;
/** Response obtained from ProxyDHCP server */
struct dhcp_iobuf_packet *proxy_response;
/** Retransmission timer */
struct retry_timer timer;
/** Session start time (in ticks) */
@@ -716,8 +443,8 @@ static void dhcp_free ( struct refcnt *refcnt ) {
container_of ( refcnt, struct dhcp_session, refcnt );
netdev_put ( dhcp->netdev );
dhcpopt_put ( dhcp->options );
dhcpopt_put ( dhcp->proxy_options );
dhcpiob_put ( dhcp->response );
dhcpiob_put ( dhcp->proxy_response );
free ( dhcp );
}
@@ -741,6 +468,31 @@ static void dhcp_finished ( struct dhcp_session *dhcp, int rc ) {
job_done ( &dhcp->job, rc );
}
/**
* Register options received via DHCP
*
* @v dhcp DHCP session
* @ret rc Return status code
*/
static int dhcp_register_settings ( struct dhcp_session *dhcp ) {
struct settings *settings;
struct settings *parent;
int rc;
if ( dhcp->proxy_response ) {
settings = &dhcp->proxy_response->dhcppkt.settings;
if ( ( rc = register_settings ( settings, NULL ) ) != 0 )
return rc;
}
settings = &dhcp->response->dhcppkt.settings;
parent = netdev_settings ( dhcp->netdev );
if ( ( rc = register_settings ( settings, parent ) ) != 0 )
return rc;
return 0;
}
/****************************************************************************
*
* Data transfer interface
@@ -757,6 +509,7 @@ static int dhcp_send_request ( struct dhcp_session *dhcp ) {
struct xfer_metadata meta = {
.netdev = dhcp->netdev,
};
struct settings *offer_settings = NULL;
struct io_buffer *iobuf;
struct dhcp_packet dhcppkt;
int rc;
@@ -778,10 +531,11 @@ static int dhcp_send_request ( struct dhcp_session *dhcp ) {
return -ENOMEM;
/* Create DHCP packet in temporary buffer */
if ( ( rc = create_dhcp_request ( dhcp->netdev, dhcp->state,
dhcp->options, iobuf->data,
iob_tailroom ( iobuf ),
&dhcppkt ) ) != 0 ) {
if ( dhcp->response )
offer_settings = &dhcp->response->dhcppkt.settings;
if ( ( rc = create_dhcp_request ( &dhcppkt, dhcp->netdev, dhcp->state,
offer_settings, iobuf->data,
iob_tailroom ( iobuf ) ) ) != 0 ) {
DBGC ( dhcp, "DHCP %p could not construct DHCP request: %s\n",
dhcp, strerror ( rc ) );
goto done;
@@ -828,36 +582,41 @@ static void dhcp_timer_expired ( struct retry_timer *timer, int fail ) {
* @v len Length of received data
* @ret rc Return status code
*/
static int dhcp_deliver_raw ( struct xfer_interface *xfer,
const void *data, size_t len ) {
static int dhcp_deliver_iob ( struct xfer_interface *xfer,
struct io_buffer *iobuf,
struct xfer_metadata *meta __unused ) {
struct dhcp_session *dhcp =
container_of ( xfer, struct dhcp_session, xfer );
const struct dhcphdr *dhcphdr = data;
struct dhcp_option_block *options;
struct dhcp_option_block **store_options;
struct dhcp_iobuf_packet *response;
struct dhcp_iobuf_packet **store_response;
struct dhcphdr *dhcphdr;
struct settings *settings;
unsigned int msgtype;
unsigned long elapsed;
int is_proxy;
int ignore_proxy;
int rc;
/* Convert packet into a DHCP-packet-in-iobuf */
response = dhcpiob_create ( iobuf );
if ( ! response ) {
DBGC ( dhcp, "DHCP %p could not store DHCP packet\n", dhcp );
return -ENOMEM;
}
dhcphdr = response->dhcppkt.dhcphdr;
settings = &response->dhcppkt.settings;
/* Check for matching transaction ID */
if ( dhcphdr->xid != dhcp_xid ( dhcp->netdev ) ) {
DBGC ( dhcp, "DHCP %p wrong transaction ID (wanted %08lx, "
"got %08lx)\n", dhcp, ntohl ( dhcphdr->xid ),
ntohl ( dhcp_xid ( dhcp->netdev ) ) );
return 0;
};
/* Parse packet and create options structure */
options = dhcp_parse ( dhcphdr, len );
if ( ! options ) {
DBGC ( dhcp, "DHCP %p could not parse DHCP packet\n", dhcp );
return -EINVAL;
}
goto out_discard;
};
/* Determine and verify message type */
is_proxy = ( dhcphdr->yiaddr.s_addr == 0 );
msgtype = find_dhcp_num_option ( options, DHCP_MESSAGE_TYPE );
msgtype = fetch_uintz_setting ( settings, DHCP_MESSAGE_TYPE );
DBGC ( dhcp, "DHCP %p received %s%s\n", dhcp,
( is_proxy ? "Proxy" : "" ), dhcp_msgtype_name ( msgtype ) );
if ( ( ( dhcp->state != DHCPDISCOVER ) || ( msgtype != DHCPOFFER ) ) &&
@@ -872,25 +631,26 @@ static int dhcp_deliver_raw ( struct xfer_interface *xfer,
* options have equal or higher priority than the
* currently-stored options.
*/
store_options = ( is_proxy ? &dhcp->proxy_options : &dhcp->options );
if ( ( ! *store_options ) ||
( find_dhcp_num_option ( options, DHCP_EB_PRIORITY ) >=
find_dhcp_num_option ( *store_options, DHCP_EB_PRIORITY ) ) ) {
dhcpopt_put ( *store_options );
*store_options = options;
store_response = ( is_proxy ? &dhcp->proxy_response : &dhcp->response);
if ( ( ! *store_response ) ||
( fetch_uintz_setting ( settings, DHCP_EB_PRIORITY ) >=
fetch_uintz_setting ( &(*store_response)->dhcppkt.settings,
DHCP_EB_PRIORITY ) ) ) {
dhcpiob_put ( *store_response );
*store_response = response;
} else {
dhcpopt_put ( options );
dhcpiob_put ( response );
}
/* If we don't yet have a standard DHCP response (i.e. one
* with an IP address), then just leave the timer running.
*/
if ( ! dhcp->options )
if ( ! dhcp->response )
goto out;
/* Handle DHCP response */
ignore_proxy = find_dhcp_num_option ( dhcp->options,
DHCP_EB_NO_PROXYDHCP );
ignore_proxy = fetch_uintz_setting ( &dhcp->response->dhcppkt.settings,
DHCP_EB_NO_PROXYDHCP );
switch ( dhcp->state ) {
case DHCPDISCOVER:
/* If we have allowed sufficient time for ProxyDHCP
@@ -905,11 +665,14 @@ static int dhcp_deliver_raw ( struct xfer_interface *xfer,
break;
case DHCPREQUEST:
/* DHCP finished; register options and exit */
if ( dhcp->proxy_options && ( ! ignore_proxy ) ) {
dhcp->register_options ( dhcp->netdev,
dhcp->proxy_options );
if ( ignore_proxy && dhcp->proxy_response ) {
dhcpiob_put ( dhcp->proxy_response );
dhcp->proxy_response = NULL;
}
if ( ( rc = dhcp_register_settings ( dhcp ) ) != 0 ) {
dhcp_finished ( dhcp, rc );
break;
}
dhcp->register_options ( dhcp->netdev, dhcp->options );
dhcp_finished ( dhcp, 0 );
break;
default:
@@ -920,7 +683,7 @@ static int dhcp_deliver_raw ( struct xfer_interface *xfer,
return 0;
out_discard:
dhcpopt_put ( options );
dhcpiob_put ( response );
return 0;
}
@@ -930,8 +693,8 @@ static struct xfer_interface_operations dhcp_xfer_operations = {
.vredirect = xfer_vopen,
.window = unlimited_xfer_window,
.alloc_iob = default_xfer_alloc_iob,
.deliver_iob = xfer_deliver_as_raw,
.deliver_raw = dhcp_deliver_raw,
.deliver_iob = dhcp_deliver_iob,
.deliver_raw = xfer_deliver_as_iob,
};
/****************************************************************************
@@ -978,9 +741,7 @@ static struct job_interface_operations dhcp_job_operations = {
* register_options() routine will be called with the acquired
* options.
*/
int start_dhcp ( struct job_interface *job, struct net_device *netdev,
int ( * register_options ) ( struct net_device *netdev,
struct dhcp_option_block * ) ) {
int start_dhcp ( struct job_interface *job, struct net_device *netdev ) {
static struct sockaddr_in server = {
.sin_family = AF_INET,
.sin_addr.s_addr = INADDR_BROADCAST,
@@ -1001,7 +762,6 @@ int start_dhcp ( struct job_interface *job, struct net_device *netdev,
job_init ( &dhcp->job, &dhcp_job_operations, &dhcp->refcnt );
xfer_init ( &dhcp->xfer, &dhcp_xfer_operations, &dhcp->refcnt );
dhcp->netdev = netdev_get ( netdev );
dhcp->register_options = register_options;
dhcp->timer.expired = dhcp_timer_expired;
dhcp->state = DHCPDISCOVER;
dhcp->start = currticks();