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systemd/src/libsystemd-network/dhcp-internal.h
Tom Gundersen 0bbc2c1f3b sd-dhcp: checksum - make endianess-neutral
For efficiency, we group bytes together before adding them up. This
is guaranteed to always work (regardless of the byte order) as long
as the i-th byte in each group lign up with the i-th byte in each
other group.

On big-endian machines this broke when handling the trailing few bytes
which did not make up a full group of 4 bytes. This patch fixes the
problem by explicitly creating a 4 byte zero-padded group out of the
trailing bytes.

Reported and tested by Thomas Ritter <th.ritter@gmx.at>.
2014-06-17 09:17:07 +02:00

60 lines
2.4 KiB
C

/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
#pragma once
/***
This file is part of systemd.
Copyright (C) 2013 Intel Corporation. All rights reserved.
Copyright (C) 2014 Tom Gundersen
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <stdint.h>
#include <linux/if_packet.h>
#include "socket-util.h"
#include "dhcp-protocol.h"
int dhcp_network_bind_raw_socket(int index, union sockaddr_union *link, uint32_t xid);
int dhcp_network_bind_udp_socket(be32_t address, uint16_t port);
int dhcp_network_send_raw_socket(int s, const union sockaddr_union *link,
const void *packet, size_t len);
int dhcp_network_send_udp_socket(int s, be32_t address, uint16_t port,
const void *packet, size_t len);
int dhcp_option_append(DHCPMessage *message, size_t size, size_t *offset, uint8_t overload,
uint8_t code, size_t optlen, const void *optval);
typedef int (*dhcp_option_cb_t)(uint8_t code, uint8_t len,
const uint8_t *option, void *user_data);
int dhcp_option_parse(DHCPMessage *message, size_t len,
dhcp_option_cb_t cb, void *user_data);
int dhcp_message_init(DHCPMessage *message, uint8_t op, uint32_t xid, uint8_t type,
size_t optlen, size_t *optoffset);
uint16_t dhcp_packet_checksum(uint8_t *buf, size_t len);
void dhcp_packet_append_ip_headers(DHCPPacket *packet, be32_t source_addr,
uint16_t source, be32_t destination_addr,
uint16_t destination, uint16_t len);
int dhcp_packet_verify_headers(DHCPPacket *packet, size_t len, bool checksum);
#define log_dhcp_client(client, fmt, ...) log_meta(LOG_DEBUG, __FILE__, __LINE__, __func__, "DHCP CLIENT (0x%x): " fmt, client->xid, ##__VA_ARGS__)