connection.h

/*
    connection.h -- header for connection.c
    Copyright (C) 2000-2016 Guus Sliepen <guus@tinc-vpn.org>,
                  2000-2005 Ivo Timmermans

    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 __TINC_CONNECTION_H__
#define __TINC_CONNECTION_H__

#include <openssl/rsa.h>
#include <openssl/evp.h>

#include "avl_tree.h"

#define OPTION_INDIRECT		0x0001
#define OPTION_TCPONLY		0x0002
#define OPTION_PMTU_DISCOVERY	0x0004
#define OPTION_CLAMP_MSS	0x0008

typedef struct connection_status_t {
	unsigned int pinged:1;				/* sent ping */
	unsigned int active:1;				/* 1 if active.. */
	unsigned int connecting:1;			/* 1 if we are waiting for a non-blocking connect() to finish */
	unsigned int unused_termreq:1;			/* the termination of this connection was requested */
	unsigned int remove:1;				/* Set to 1 if you want this connection removed */
	unsigned int timeout:1;				/* 1 if gotten timeout */
	unsigned int encryptout:1;			/* 1 if we can encrypt outgoing traffic */
	unsigned int decryptin:1;			/* 1 if we have to decrypt incoming traffic */
	unsigned int mst:1;				/* 1 if this connection is part of a minimum spanning tree */
	unsigned int proxy_passed:1;			/* 1 if we are connecting via a proxy and we have finished talking with it */
	unsigned int unused:22;
} connection_status_t;

#include "edge.h"
#include "net.h"
#include "node.h"

typedef struct connection_t {
	char *name;					/* name he claims to have */

	union sockaddr_t address;			/* his real (internet) ip */
	char *hostname;				/* the hostname of its real ip */
	int protocol_version;		/* used protocol */

	int socket;					/* socket used for this connection */
	uint32_t options;			/* options for this connection */
	connection_status_t status;	/* status info */
	int estimated_weight;		/* estimation for the weight of the edge for this connection */
	struct timeval start;		/* time this connection was started, used for above estimation */
	struct outgoing_t *outgoing;	/* used to keep track of outgoing connections */

	struct node_t *node;		/* node associated with the other end */
	struct edge_t *edge;		/* edge associated with this connection */

	RSA *rsa_key;				/* his public/private key */
	const EVP_CIPHER *incipher;	/* Cipher he will use to send data to us */
	const EVP_CIPHER *outcipher;	/* Cipher we will use to send data to him */
	EVP_CIPHER_CTX *inctx;		/* Context of encrypted meta data that will come from him to us */
	EVP_CIPHER_CTX *outctx;		/* Context of encrypted meta data that will be sent from us to him */
	uint64_t inbudget;              /* Encrypted bytes send budget */
	uint64_t outbudget;             /* Encrypted bytes receive budget */
	char *inkey;				/* His symmetric meta key + iv */
	char *outkey;				/* Our symmetric meta key + iv */
	int inkeylength;			/* Length of his key + iv */
	int outkeylength;			/* Length of our key + iv */
	const EVP_MD *indigest;
	const EVP_MD *outdigest;
	int inmaclength;
	int outmaclength;
	int incompression;
	int outcompression;
	char *mychallenge;			/* challenge we received from him */
	char *hischallenge;			/* challenge we sent to him */

	char buffer[MAXBUFSIZE];	/* metadata input buffer */
	int buflen;					/* bytes read into buffer */
	int reqlen;					/* length of incoming request */
	int tcplen;					/* length of incoming TCPpacket */
	int allow_request;			/* defined if there's only one request possible */

	char *outbuf;				/* metadata output buffer */
	int outbufstart;			/* index of first meaningful byte in output buffer */
	int outbuflen;				/* number of meaningful bytes in output buffer */
	int outbufsize;				/* number of bytes allocated to output buffer */

	time_t last_ping_time;		/* last time we saw some activity from the other end or pinged them */
	time_t last_flushed_time;	/* last time buffer was empty. Only meaningful if outbuflen > 0 */

	avl_tree_t *config_tree;	/* Pointer to configuration tree belonging to him */
} connection_t;

extern avl_tree_t *connection_tree;
extern connection_t *everyone;

extern void init_connections(void);
extern void exit_connections(void);
extern connection_t *new_connection(void) __attribute__ ((__malloc__));
extern void free_connection(connection_t *);
extern void free_connection_partially(connection_t *);
extern void connection_add(connection_t *);
extern void connection_del(connection_t *);
extern void dump_connections(void);

#endif							/* __TINC_CONNECTION_H__ */