badvpn/misc/ipv6_proto.h

87 lines
2.8 KiB
C

/**
* @file ipv6_proto.h
* @author Ambroz Bizjak <ambrop7@gmail.com>
*
* @section LICENSE
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the author nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef BADVPN_IPV6_PROTO_H
#define BADVPN_IPV6_PROTO_H
#include <stdint.h>
#include <string.h>
#include <misc/debug.h>
#include <misc/byteorder.h>
#include <misc/packed.h>
#define IPV6_NEXT_IGMP 2
#define IPV6_NEXT_UDP 17
B_START_PACKED
struct ipv6_header {
uint8_t version4_tc4;
uint8_t tc4_fl4;
uint16_t fl;
uint16_t payload_length;
uint8_t next_header;
uint8_t hop_limit;
uint8_t source_address[16];
uint8_t destination_address[16];
} B_PACKED;
B_END_PACKED
static int ipv6_check (uint8_t *data, int data_len, struct ipv6_header *out_header, uint8_t **out_payload, int *out_payload_len)
{
ASSERT(data_len >= 0)
ASSERT(out_header)
ASSERT(out_payload)
ASSERT(out_payload_len)
// check base header
if (data_len < sizeof(struct ipv6_header)) {
return 0;
}
memcpy(out_header, data, sizeof(*out_header));
// check version
if ((ntoh8(out_header->version4_tc4) >> 4) != 6) {
return 0;
}
// check payload length
uint16_t payload_length = ntoh16(out_header->payload_length);
if (payload_length > data_len - sizeof(struct ipv6_header)) {
return 0;
}
*out_payload = data + sizeof(struct ipv6_header);
*out_payload_len = payload_length;
return 1;
}
#endif