path: root/src/peer.h

/*
  Copyright (c) 2012-2014, Matthias Schiffer <mschiffer@universe-factory.net>
  All rights reserved.

  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.

  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 COPYRIGHT HOLDER OR CONTRIBUTORS 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.
*/

/**
   \file peer.h

   Structures and functions for peer management
*/


#pragma once

#include "fastd.h"


/** The state of a peer */
typedef enum fastd_peer_state {
	STATE_INIT = 0,					/**< The peer peer was just created */
	STATE_RESOLVING,				/**< The peer is currently resolving its first remote */
	STATE_HANDSHAKE,				/**< The peer has tried to perform a handshake */
	STATE_ESTABLISHED,				/**< The peer has established a connection */
} fastd_peer_state_t;

/** Dynamic state of a peer */
struct fastd_peer {
	uint64_t id;					/**< A unique ID assigned to each peer */

	const fastd_peer_config_t *config;		/**< The peer's fastd_peer_config_t */
	fastd_peer_group_t *group;			/**< The peer's peer group */

	/** The socket used by the peer. This can either be a common bound socket or a
	    dynamic, unbound socket that is used exclusively by this peer */
	fastd_socket_t *sock;
	fastd_peer_address_t local_address;		/**< The local address used to communicate with this peer */
	fastd_peer_address_t address;			/**< The peers current address */

	fastd_peer_state_t state;			/**< The peer's state */
	struct timespec timeout;			/**< The timeout after which the peer is reset */
	struct timespec keepalive_timeout;		/**< The timeout after which a keepalive is sent to the peer */

	VECTOR(fastd_remote_t) remotes;			/**< The vector of the peer's remotes */
	ssize_t next_remote;				/**< An index into the field remotes or -1 */

	struct timespec next_handshake;			/**< The time of the next handshake */
	fastd_dlist_head_t handshake_entry;		/**< Entry in the handshake queue */

	struct timespec last_handshake_timeout;		/**< No handshakes are sent to the peer until this timeout has occured to avoid flooding the peer */
	fastd_peer_address_t last_handshake_address;	/**< The address the last handshake was sent to */

	struct timespec last_handshake_response_timeout; /**< All handshakes from last_handshake_address will be ignored until this timeout has occured */
	fastd_peer_address_t last_handshake_response_address; /**< The address the last handshake was received from */

	struct timespec establish_handshake_timeout;	/**< A timeout during which all handshakes for this peer will be ignored after a new connection has been established */

#ifdef WITH_VERIFY
	struct timespec verify_timeout;			/**< Specifies the minimum time after which on-verify may be run again */
	struct timespec verify_valid_timeout;		/**< Specifies how long a peer stays valid after a successful on-verify run */
#endif

	fastd_protocol_peer_config_t *protocol_config;	/**< Protocol-specific peer configuration for config-less (on-verify) peers */
	fastd_protocol_peer_state_t *protocol_state;	/**< Protocol-specific peer state */
};

/**
   Static configuration of a peer

   Peer configurations are kept in a linked list.
*/
struct fastd_peer_config {
	fastd_peer_config_t *next;			/**< The next peer configuration */

	const char *config_source_dir;			/**< The directory this peer's configuration was loaded from */

	bool enabled;					/**< Speficies if this peer was disabled because of a configuration error */
	char *name;					/**< The peer's name */

	fastd_remote_config_t *remotes;			/**< A linked list of the peer's remote entries */
	char *key;					/**< The peer's public key */
	bool floating;					/**< Specifies if the peer has any floating remotes (or no remotes at all) */
	const fastd_peer_group_config_t *group;		/**< The peer group the peer belongs to */

	fastd_protocol_peer_config_t *protocol_config;	/**< The protocol-specific configuration of the peer */
};

struct fastd_peer_group {
	fastd_peer_group_t *next;
	fastd_peer_group_t *parent;
	fastd_peer_group_t *children;

	const fastd_peer_group_config_t *conf;
};

struct fastd_peer_group_config {
	fastd_peer_group_config_t *next;
	fastd_peer_group_config_t *parent;
	fastd_peer_group_config_t *children;

	char *name;
	fastd_string_stack_t *peer_dirs;

	/* constraints */
	int max_connections;
};

struct fastd_peer_eth_addr {
	fastd_eth_addr_t addr;
	fastd_peer_t *peer;
	struct timespec timeout;
};

struct fastd_remote {
	fastd_remote_config_t *config;

	size_t n_addresses;
	size_t current_address;
	fastd_peer_address_t *addresses;

	struct timespec last_resolve_timeout;
};

struct fastd_remote_config {
	fastd_remote_config_t *next;

	char *hostname;
	fastd_peer_address_t address;
};


bool fastd_peer_address_equal(const fastd_peer_address_t *addr1, const fastd_peer_address_t *addr2);
void fastd_peer_address_simplify(fastd_peer_address_t *addr);
void fastd_peer_address_widen(fastd_peer_address_t *addr);

static inline uint16_t fastd_peer_address_get_port(const fastd_peer_address_t *addr) {
	switch (addr->sa.sa_family) {
	case AF_INET:
		return addr->in.sin_port;

	case AF_INET6:
		return addr->in6.sin6_port;

	default:
		return 0;
	}
}

fastd_peer_config_t* fastd_peer_config_new(void);
void fastd_peer_config_free(fastd_peer_config_t *peer);
void fastd_peer_config_delete(void);
void fastd_peer_config_purge(fastd_peer_config_t *config);
bool fastd_peer_config_equal(const fastd_peer_config_t *peer1, const fastd_peer_config_t *peer2);

void fastd_peer_reset(fastd_peer_t *peer);
void fastd_peer_delete(fastd_peer_t *peer);
fastd_peer_t* fastd_peer_add(fastd_peer_config_t *peer_conf);
void fastd_peer_set_established(fastd_peer_t *peer);
bool fastd_peer_may_connect(fastd_peer_t *peer);
void fastd_peer_handle_resolve(fastd_peer_t *peer, fastd_remote_t *remote, size_t n_addresses, const fastd_peer_address_t *addresses);
bool fastd_peer_owns_address(const fastd_peer_t *peer, const fastd_peer_address_t *addr);
bool fastd_peer_matches_address(const fastd_peer_t *peer, const fastd_peer_address_t *addr);
bool fastd_peer_claim_address(fastd_peer_t *peer, fastd_socket_t *sock, const fastd_peer_address_t *local_addr, const fastd_peer_address_t *remote_addr, bool force);
void fastd_peer_reset_socket(fastd_peer_t *peer);
void fastd_peer_schedule_handshake(fastd_peer_t *peer, int delay);
fastd_peer_t* fastd_peer_find_by_id(uint64_t id);

void fastd_peer_set_shell_env(fastd_shell_env_t *env, const fastd_peer_t *peer, const fastd_peer_address_t *local_addr, const fastd_peer_address_t *peer_addr);
void fastd_peer_exec_shell_command(const fastd_shell_command_t *command, const fastd_peer_t *peer, const fastd_peer_address_t *local_addr, const fastd_peer_address_t *peer_addr);

static inline void fastd_peer_schedule_handshake_default(fastd_peer_t *peer) {
	fastd_peer_schedule_handshake(peer, fastd_rand(17500, 22500));
}

static inline void fastd_peer_unschedule_handshake(fastd_peer_t *peer) {
	fastd_dlist_remove(&peer->handshake_entry);
}

#ifdef WITH_VERIFY
static inline void fastd_peer_set_verifying(fastd_peer_t *peer) {
	peer->verify_timeout = fastd_in_seconds(MIN_VERIFY_INTERVAL);
}

static inline void fastd_peer_set_verified(fastd_peer_t *peer, bool ok) {
	if (ok)
		peer->verify_valid_timeout = fastd_in_seconds(VERIFY_VALID_TIME);
	else
		peer->verify_valid_timeout = ctx.now;
}
#endif

static inline bool fastd_peer_handshake_scheduled(fastd_peer_t *peer) {
	return fastd_dlist_linked(&peer->handshake_entry);
}

static inline bool fastd_peer_config_is_floating(const fastd_peer_config_t *config) {
	return (!config->remotes || config->floating);
}

bool fastd_remote_matches_dynamic(const fastd_remote_config_t *remote, const fastd_peer_address_t *addr);

static inline bool fastd_peer_is_floating(const fastd_peer_t *peer) {
	return peer->config ? fastd_peer_config_is_floating(peer->config) : true;
}

static inline bool fastd_peer_is_temporary(const fastd_peer_t *peer) {
	return (!peer->config);
}

static inline fastd_remote_t * fastd_peer_get_next_remote(fastd_peer_t *peer) {
	if (peer->next_remote < 0)
	     return NULL;

	return &VECTOR_INDEX(peer->remotes, peer->next_remote);
}

static inline bool fastd_peer_is_established(const fastd_peer_t *peer) {
	switch(peer->state) {
	case STATE_ESTABLISHED:
		return true;

	default:
		return false;
	}
}

static inline bool fastd_remote_is_dynamic(const fastd_remote_t *remote) {
	return remote->config->hostname;
}

static inline void fastd_peer_seen(fastd_peer_t *peer) {
	peer->timeout = fastd_in_seconds(PEER_STALE_TIME);
}

static inline bool fastd_peer_is_socket_dynamic(const fastd_peer_t *peer) {
	return (!peer->sock || !peer->sock->addr);
}

static inline bool fastd_eth_addr_is_unicast(fastd_eth_addr_t addr) {
	return ((addr.data[0] & 1) == 0);
}

void fastd_peer_eth_addr_add(fastd_peer_t *peer, fastd_eth_addr_t addr);
fastd_peer_t* fastd_peer_find_by_eth_addr(fastd_eth_addr_t addr);

void fastd_peer_handle_handshake_queue(void);
void fastd_peer_maintenance(void);