serval-dna/overlay_address.h

113 lines
3.6 KiB
C

/*
Serval Daemon
Copyright (C) 2012 Serval Project Inc.
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 (at your option) 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#ifndef _SERVALD_OVERLAY_ADDRESS_H
#define _SERVALD_OVERLAY_ADDRESS_H
#include "constants.h"
// not reachable
#define REACHABLE_NONE 0
// immediate neighbour
#define REACHABLE_DIRECT 1
// packets must be routed
#define REACHABLE_INDIRECT 2
// packets can probably be flooded to this peer with ttl=2
// (temporary state for new peers before path discovery has finished)
#define REACHABLE_BROADCAST 3
// this subscriber is in our keystore
#define REACHABLE_SELF 4
/* Codes used to describe abbreviated addresses.
Values 0x10 - 0xff are the first byte of, and implicit indicators of addresses written in full */
#define OA_CODE_SELF 0x00
#define OA_CODE_INDEX 0x01
#define OA_CODE_02 0x02
#define OA_CODE_PREVIOUS 0x03
#define OA_CODE_04 0x04
#define OA_CODE_PREFIX3 0x05
#define OA_CODE_PREFIX7 0x06
#define OA_CODE_PREFIX11 0x07
#define OA_CODE_FULL_INDEX1 0x08
#define OA_CODE_PREFIX3_INDEX1 0x09
#define OA_CODE_PREFIX7_INDEX1 0x0a
#define OA_CODE_PREFIX11_INDEX1 0x0b
#define OA_CODE_0C 0x0c
#define OA_CODE_PREFIX11_INDEX2 0x0d
#define OA_CODE_FULL_INDEX2 0x0e
/* The TTL field in a frame is used to differentiate between link-local and wide-area broadcasts */
#define OA_CODE_BROADCAST 0x0f
#define BROADCAST_LEN 8
// This structure supports both our own routing protocol which can store calculation details in *node
// or IP4 addresses reachable via any other kind of normal layer3 routing protocol, eg olsr
struct subscriber{
unsigned char sid[SID_SIZE];
// minimum abbreviation length, in 4bit nibbles.
int abbreviate_len;
// should we send the full address once?
int send_full;
// overlay routing information
struct overlay_node *node;
// result of routing calculations;
int reachable;
union{
// if indirect, who is the next hop?
struct subscriber *next_hop;
struct{
// if direct, where do we send packets?
struct overlay_interface *interface;
// if s_addr == INADDR_ANY, send to the interface broadcast address
struct sockaddr_in address;
};
};
};
struct broadcast{
unsigned char id[BROADCAST_LEN];
};
extern struct subscriber *my_subscriber;
struct subscriber *find_subscriber(const unsigned char *sid, int len, int create);
void enum_subscribers(struct subscriber *start, int(*callback)(struct subscriber *, void *), void *context);
int subscriber_is_reachable(struct subscriber *subscriber);
int overlay_broadcast_drop_check(struct broadcast *addr);
int overlay_broadcast_generate_address(struct broadcast *addr);
int overlay_broadcast_append(struct overlay_buffer *b, struct broadcast *broadcast);
int overlay_address_append(struct overlay_buffer *b, struct subscriber *subscriber);
int overlay_address_parse(struct overlay_buffer *b, struct broadcast *broadcast, struct subscriber **subscriber);
void overlay_address_clear(void);
void overlay_address_set_sender(struct subscriber *subscriber);
#endif