diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 16:29:52 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 16:29:52 +0000 |
commit | ca67b09c015d4af3ae3cce12aa72e60941dbb8b5 (patch) | |
tree | b7316d7b06c373e08dabb79a2c866c568e08f49e /debian/grub-extras/disabled/gpxe/src/net/dhcpopts.c | |
parent | Adding upstream version 2.06. (diff) | |
download | grub2-ca67b09c015d4af3ae3cce12aa72e60941dbb8b5.tar.xz grub2-ca67b09c015d4af3ae3cce12aa72e60941dbb8b5.zip |
Adding debian version 2.06-13+deb12u1.debian/2.06-13+deb12u1debian
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'debian/grub-extras/disabled/gpxe/src/net/dhcpopts.c')
-rw-r--r-- | debian/grub-extras/disabled/gpxe/src/net/dhcpopts.c | 436 |
1 files changed, 436 insertions, 0 deletions
diff --git a/debian/grub-extras/disabled/gpxe/src/net/dhcpopts.c b/debian/grub-extras/disabled/gpxe/src/net/dhcpopts.c new file mode 100644 index 0000000..c1940f1 --- /dev/null +++ b/debian/grub-extras/disabled/gpxe/src/net/dhcpopts.c @@ -0,0 +1,436 @@ +/* + * 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. + */ + +FILE_LICENCE ( GPL2_OR_LATER ); + +#include <stdint.h> +#include <stdlib.h> +#include <stdio.h> +#include <errno.h> +#include <string.h> +#include <gpxe/dhcp.h> +#include <gpxe/dhcpopts.h> + +/** @file + * + * DHCP options + * + */ + +/** + * Obtain printable version of a DHCP option tag + * + * @v tag DHCP option tag + * @ret name String representation of the tag + * + */ +static inline char * dhcp_tag_name ( unsigned int tag ) { + static char name[8]; + + if ( DHCP_IS_ENCAP_OPT ( tag ) ) { + snprintf ( name, sizeof ( name ), "%d.%d", + DHCP_ENCAPSULATOR ( tag ), + DHCP_ENCAPSULATED ( tag ) ); + } else { + snprintf ( name, sizeof ( name ), "%d", tag ); + } + return name; +} + +/** + * Get pointer to DHCP option + * + * @v options DHCP options block + * @v offset Offset within options block + * @ret option DHCP option + */ +static inline __attribute__ (( always_inline )) struct dhcp_option * +dhcp_option ( struct dhcp_options *options, unsigned int offset ) { + return ( ( struct dhcp_option * ) ( options->data + offset ) ); +} + +/** + * Get offset of a DHCP option + * + * @v options DHCP options block + * @v option DHCP option + * @ret offset Offset within options block + */ +static inline __attribute__ (( always_inline )) int +dhcp_option_offset ( struct dhcp_options *options, + struct dhcp_option *option ) { + return ( ( ( void * ) option ) - options->data ); +} + +/** + * Calculate length of any DHCP option + * + * @v option DHCP option + * @ret len Length (including tag and length field) + */ +static unsigned int dhcp_option_len ( struct dhcp_option *option ) { + if ( ( option->tag == DHCP_END ) || ( option->tag == DHCP_PAD ) ) { + return 1; + } else { + return ( option->len + DHCP_OPTION_HEADER_LEN ); + } +} + +/** + * Find DHCP option within DHCP options block, and its encapsulator (if any) + * + * @v options DHCP options block + * @v tag DHCP option tag to search for + * @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 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 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; + int offset = 0; + ssize_t remaining = options->len; + unsigned int option_len; + + /* Sanity check */ + if ( tag == DHCP_PAD ) + return -ENOENT; + + /* Search for option */ + while ( remaining ) { + /* Calculate length of this option. Abort processing + * if the length is malformed (i.e. takes us beyond + * the end of the data block). + */ + option = dhcp_option ( options, offset ); + option_len = dhcp_option_len ( option ); + remaining -= option_len; + if ( remaining < 0 ) + break; + /* Check for explicit end marker */ + if ( option->tag == DHCP_END ) + break; + /* Check for matching tag */ + if ( option->tag == tag ) { + DBGC ( options, "DHCPOPT %p found %s (length %d)\n", + options, dhcp_tag_name ( original_tag ), + option_len ); + return offset; + } + /* Check for start of matching encapsulation block */ + if ( DHCP_IS_ENCAP_OPT ( tag ) && + ( option->tag == DHCP_ENCAPSULATOR ( tag ) ) ) { + if ( encap_offset ) + *encap_offset = offset; + /* Continue search within encapsulated option block */ + tag = DHCP_ENCAPSULATED ( tag ); + remaining = option_len; + offset += DHCP_OPTION_HEADER_LEN; + continue; + } + offset += option_len; + } + + return -ENOENT; +} + +/** + * Resize a DHCP option + * + * @v options DHCP option block + * @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_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 ) { + DBGC ( options, "DHCPOPT %p overlength option\n", options ); + return -ENOSPC; + } + new_options_len = ( options->len + delta ); + 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 ) { + DBGC ( options, "DHCPOPT %p could not " + "reallocate to %zd bytes\n", options, + new_options_len ); + return -ENOMEM; + } + options->data = new_data; + options->max_len = new_options_len; + } else { + DBGC ( options, "DHCPOPT %p out of space\n", options ); + 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 ) { + DBGC ( options, "DHCPOPT %p overlength encapsulator\n", + options ); + 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; +} + +/** + * Set value of DHCP option + * + * @v options DHCP option block + * @v tag DHCP option tag + * @v data New value for DHCP option + * @v len Length of value, in bytes + * @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 + * (and deleted) as necessary. + * + * This call may fail due to insufficient space in the options block. + * If it does fail, and the option existed previously, the option will + * be left with its original value. + */ +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; + unsigned int encap_tag = DHCP_ENCAPSULATOR ( tag ); + size_t old_len = 0; + size_t new_len = ( len ? ( len + DHCP_OPTION_HEADER_LEN ) : 0 ); + int rc; + + /* Sanity check */ + if ( tag == DHCP_PAD ) + return -ENOTTY; + + /* Find old instance of this option, if any */ + 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 { + DBGC ( options, "DHCPOPT %p creating %s (length %zd)\n", + options, dhcp_tag_name ( tag ), new_len ); + } + + /* Ensure that encapsulator exists, if required */ + 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 ( offset < 0 ) + offset = creation_offset; + + /* Resize option to fit new data */ + 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 ( encap_offset >= 0 ) { + option = dhcp_option ( options, encap_offset ); + if ( option->len <= 1 ) + set_dhcp_option ( options, encap_tag, NULL, 0, 0 ); + } + + return offset; +} + +/** + * Store value of DHCP option setting + * + * @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 + */ +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; +} + +/** + * Store value of DHCP option setting, extending options block if necessary + * + * @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 + */ +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 = option->len; + 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 ); +} |