fa.h

mobile ip 在linux下的一种实现

/* $Id: fa.h,v 1.103 2001/09/25 17:14:20 jm Exp $
 * Header files for Foreign Agent
 *
 * Dynamic hierarchial IP tunnel
 * Copyright (C) 1998-2001, Dynamics group
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation. See README and COPYING for
 * more details.
 */

#ifndef FA_H
#define FA_H

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <asm/types.h>
#include <net/if.h>
#include <netinet/in.h>
#include <sys/time.h>

#include <features.h>    /* for the glibc version number */
#if __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 1
#include <netpacket/packet.h>
#else
#include <linux/if_packet.h>
#endif
#include <netinet/ip.h>
#include <netinet/udp.h>

#include "binding.h"
#include "message.h"
#include "msgparser.h"

#define DEBUG_FLAG 'F'
#define DEBUG_FLAG2 'f'

#define LOG2(lev, fmt, args...) do { DEBUG(DEBUG_FLAG, fmt, ## args); \
  syslog(lev, fmt, ## args); } while(0)


/* Delay binding removal DELAY_BINDING_TIME seconds (fa_reply.c:
   handle_reply_disconnect() */
#define DELAY_BINDING_TIME                  2
#define MAXFILENAMELEN                      256
#define MAXOWNERNAMELEN                     8
#define MAXGROUPNAMELEN                     8
#define FA_DEFAULT_MAX_BINDINGS             20
#define FA_DEFAULT_ADVERTISEMENT_INTERVAL   30
#define FA_DEFAULT_SEND_ADVERTISEMENTS      TRUE
#define FA_DEFAULT_TUNNEL_LIFETIME          400
#define FA_DEFAULT_SYSLOG_FACILITY          LOG_LOCAL0
#define FA_DEFAULT_ROUTING_TABLE_START      1
#define FA_DEFAULT_ROUTING_TABLE_END        252
#define FA_DEFAULT_UDP_PORT                 434
#define FA_CONF_FILE         "dynfad.conf"
#define FA_GLOBAL_CONF_FILE  SYSCONFDIR "/" FA_CONF_FILE 
/* The process id of the daemon is saved here to make it easier to
   kill the correct daemon when necessary. */
#define FA_PID_FILE                  PIDDIR "/dynfad.pid"

#define MAXMSG 2048
/* the unconfirmed request data can be deleted after it is older than
 * UNCONFIRMED_TIMEOUT seconds */
#define UNCONFIRMED_TIMEOUT 15

#define TRUE 1
#define FALSE 0


#define TUNNEL_MODE_REVERSE 1
#define TUNNEL_MODE_TRIANGLE 2

#define TTL_CHECK_NONE 0
#define TTL_CHECK_REVERSE 1
#define TTL_CHECK_ALL 2

#define MAX_ADV_DELAY 200000.0 /* wait random 0 - MAX_ADV_DELAY microseconds 
				  befora sending agent advertisement (either 
				  broadcast or unicast, answer to agent 
				  solicitation */

#define MAXSHAREDSECRETLEN                  32

/* FA info socket - message type */
#define FA_INFO_REQUEST 1
#define FA_INFO_REPLY 2
#define FA_INFO_TIMEOUT 3
#define FA_INFO_CLOSE 4

/* FA info socket - message status */
#define FA_INFO_OK 0
#define FA_INFO_FAILED 1


#define SPI_AGENT_FA 1
#define SPI_AGENT_HA 2
#define SPI_AGENT_MN 3

struct fa_spi_entry {
	struct node node;
	int spi;
	struct in_addr addr;
	int alg;
	unsigned char shared_secret[MAXSHAREDSECRETLEN];
	int shared_secret_len;
	int agent_type;
};


#define INTERFACE_TYPE_BOTH 1
#define INTERFACE_TYPE_UP 2
#define INTERFACE_TYPE_DOWN 3

enum {
	INTERFACE_AGENTADV_ONLY_SOLICITED = 0,
	INTERFACE_AGENTADV_ALL = 1,
	INTERFACE_AGENTADV_NONE = -1 
};

struct interface_entry {
	struct node node;

	/* data from dynfad.conf */
	char dev[IFNAMSIZ + 1];
	int type; /* see above defines of INTERFACE_TYPE* */
	int agentadv; /* whether to send agent advertisements or not */
	int interval; /* interval to send advertisements */
	struct in_addr force_addr; /* which source address to use if multiple
				    * addresses available for interface */

	/* other data */
	int if_index;
	struct in_addr addr; /* local address to be used for this interface */
	struct timeval last_adv;
	int icmp_sock, udp_sock, udp_packet;
};


#define MAX_HASH_LEN 16
enum { PACKET_SOCKET_MODE_SEND = 0, PACKET_SOCKET_MODE_ONLY_RECEIVE = 1 };

struct fa_config {
	struct in_addr highest_fa_addr;
	struct in_addr upper_fa_addr;
	int highest_FA;
	int upper_fa_port;
	char tunnel_device[IFNAMSIZ + 1];
	int udp_port;
	int ha_udp_port;
	int routing_table_start;
	int routing_table_end;
        char key_file[MAXFILENAMELEN + 1];
        int max_bindings;
	int max_pending;
	int delete_pending_after;
        int enable_fa_decapsulation;
        int enable_triangle_tunneling;
	int force_reverse_tunneling;
	int enable_reverse_tunneling;
	int reg_required;
        int fa_default_tunnel_lifetime;
        int syslog_facility;
        char fa_api_read_socket_path[MAXFILENAMELEN + 1];
        char fa_api_read_socket_group[MAXGROUPNAMELEN + 1];
        char fa_api_read_socket_owner[MAXOWNERNAMELEN + 1];
        int fa_api_read_socket_permissions;
        char fa_api_admin_socket_path[MAXFILENAMELEN + 1];
        char fa_api_admin_socket_group[MAXGROUPNAMELEN + 1];
        char fa_api_admin_socket_owner[MAXOWNERNAMELEN + 1];
        int fa_api_admin_socket_permissions;
	struct list *authorized_networks;
	struct list fa_spi_list;
	struct list interfaces;
	int allow_mobile_nodes;
	int socket_priority;
	int reg_ttl_check;
	unsigned char hfa_pubkey_hash[MAX_HASH_LEN + 1];
	int hfa_pubkey_hash_len;
	char fa_nai[MAX_NAI_LEN + 1];
	int fa_nai_len;
	int send_sfa_debug_ext;
	int fa_reg_lifetime;
	int enable_challenge_response;
	int challenge_window;
	int challenge_length;
	int require_challenge;
	int challenge_in_reg_reply;
	int require_mnfa_sec_assoc;
	int packet_socket_mode; /* PACKET_SOCKET_MODE_* */
#ifdef INCLUDE_IPAY
	struct in_addr aaaf_addr; /* AAAF address (and UDP port below) for
				   * messages from HFA to AAAF */
	int aaaf_port;
	int ipay_port; /* the UDP port used for Ipay messages to this FA */
	int timePrice;
	int bytePrice;
#endif
};


struct packet_from_info {
	struct sockaddr_ll from;
	struct interface_entry *iface;
	int ttl;
	struct in_addr dst_addr;
	struct sockaddr_in src;
};


/* if there is more than one unconfirmed request or unconfirmed
 * requests to a confirmed binding, then the request data is saved in
 * unconfirmed_request structures and the correct one will be used
 * after the HA's reply is received */
struct unconfirmed_request {
	struct unconfirmed_request *next;
	time_t created;              /* creation time */
	struct msg_key *fa_pubkey;   /* lower FA public key */
	struct packet_from_info info; /* request source data (L2/L3) */
	__u32 id[2];                 /* id field from the req. */
	int spi;                     /* MN spi */
	int fa_spi;                  /* possible FA keyreq spi */
	struct in_addr ha_addr;      /* Home Agent address from the req. */
	int timeout;
	int tunnel_mode;
	int fa_decapsulation;
	int encaps_delivery; /* encapsulating delivery style [RFC 2344] */
	int is_lowest_fa;
	int old_if_index; /* same as iface->if_index; used to fix the iface
			   * pointer after configuration file reload */
	int tunnel_type;
	__u32 tunnel_key;
	int mn_nai_included; /* whether MN NAI extension was in the request */
	struct challenge_ext *challenge; /* challenge ext. in the request or
					  * NULL if not used */
	struct reg_req req; /* registration request data */
};

#ifdef INCLUDE_IPAY

struct nai_data {
	int len;
	char *nai;
};

#endif

struct tunnel_data {
	struct msg_key *fa_pubkey;            /* lower FA public key */
	struct unconfirmed_request *unc_req;  /* list of unconfirmed req. */
	struct msg_key *last_sent_fa_pubkeyrep;  
	struct msg_key *last_recv_fa_pubkeyrep;
	int tunnel_mode; /* TUNNEL_MODE_{REVERSE/TRIANGLE} */
	int fa_decapsulation;
	int encaps_delivery; /* encapsulating delivery style [RFC 2344] */
	int is_lowest_fa;
	int dynamics_extensions; /* whether the upper mobility agent supports
				  * Dynamics extensions */
#ifdef USE_TEARDOWN
	__u32 upper_id[2]; /* previously used id with the upper FA
			    * (this may differ with binding->id) */
#endif
	__u32 last_used_seq_num; /* used for local locupd replay protection */
	int req_lifetime; /* lifetime used in the request */
	int pending_request; /* is the last request pending (i.e., waiting a
			      * reply)? */
	char ha_tun_dev[IFNAMSIZ]; /* device for the HA tunnel in
				    * the highest FA */
	int old_if_index; /* same as iface->if_index; used to fix the iface
			   * pointer after configuration file reload */
	struct packet_from_info info; /* L2&L3 data from last req */
	int confirmed; /* confirmed binding = 1, unconfirmed = 0 */
	int up_type, down_type; /* TUNNEL_IPIP / TUNNEL_GRE */
	__u32 up_key, down_key; /* GRE tunnel key - to upper/lower FA */
	struct tunnel *up_tunl;
	struct tunnel *down_tunl;
	char force_route_dev[IFNAMSIZ];
	char force_reverse_dev[IFNAMSIZ];
	int mn_addr_added; /* 0 = mn_addr_add() not used, 1 = used */
	struct challenge_ext *last_challenge; /* last challenge send in
					       * registration reply */
	struct challenge_ext **used_challenges; /* rotating buffer of last
						 * 2 * CHALLENGE_WINDOW
						 * challenges the MN has used
						 */
	int used_challenges_pos; /* position in used_challenges array */
	__u32 used_challenges_id[2]; /* reg_req id used with last challenge */
	int arpentry; /* 1=permanent ARP entry is added, 0=not */
	struct in_addr arp_ipaddr;
	char arp_dev[IFNAMSIZ + 1];
#ifdef INCLUDE_IPAY
	struct nai_data mn_nai;
	int ipay_send_stats; /* 1 = send Ipay statistics */
	time_t ipay_last_stats; /* last time Ipay statistics was sent */
#endif
};

struct binding_counters {
	int bindingcount; /* the number of confirmed bindings */
	int pendingcount; /* the number of pending registrations */
};

/* used in fa_request and fa_reply to save old binding info */
struct saved_binding_info {
	struct in_addr lower_addr;
	unsigned short lower_port;
	int is_lowest_fa;
	int tunnel_mode;
	int fa_decapsulation;
	int encaps_delivery;
	int down_type;
	__u32 down_key;
	struct interface_entry *down_iface;
	struct tunnel *down_tunl;
	char force_route_dev[IFNAMSIZ];
	char force_reverse_dev[IFNAMSIZ];
};


/* function prototypes - fa.c */
struct fa_spi_entry *get_fa_spi(int spi, struct in_addr addr, int agent_type);

/* function prototypes - fa_request.c */
int add_fa_auth_ext(struct in_addr lower_addr, struct in_addr home_addr,
		    unsigned char *data, unsigned char *pos);
void save_binding_info(struct saved_binding_info *save,
		       const struct bindingentry *binding);
int handle_lower_switch(struct bindingentry *binding,
			struct saved_binding_info *old,
			struct msg_extensions *ext,
			struct in_addr *addr,
			int request_auth_ok);
int handle_request(struct msg_extensions *ext, struct packet_from_info *info,
		   struct fa_config *config);
void expire_denial_records(int force);
int send_failure_reply(int code, struct msg_extensions *ext,
		       struct packet_from_info *info, unsigned char *sk,
		       int sk_len);

/* function prototypes - fa_reply.c */
int handle_reply(struct msg_extensions *ext, struct packet_from_info *info);


/* function prototypes - fa_config.c */
int load_fa(struct fa_config *fa, char *program_name, char *config_file);
void cleanup_fa_config(struct fa_config *config);

/* function prototypes - fa_utils.c */
int send_address_ok(struct in_addr to_addr);
int own_sendto(int sock, struct in_addr to_addr, unsigned int to_port,
	       void *data, int len);
void close_socket(int fd);
void free_unconfirmed_data(struct unconfirmed_request *unc);
int eliminate_binding_entry(struct node *node, void *data);
int eliminate_binding_entry_force(struct node *node, void *data);
int update_binding(struct bindingtable *hash, struct bindingentry *binding,
		   struct binding_counters *bcounters);
struct bindingentry *
make_new_binding(struct bindingtable *bhash, struct msg_extensions *ext,
		 int max_lifetime, struct binding_counters *bcounters);
int equal_pubkey(struct msg_key *key1, struct msg_key *key2);
int do_rsa_decrypt(struct msg_key *keyrep, unsigned char *sk, int sk_len);
int create_tunnels(struct bindingentry *binding, struct hashtable *thash,
		   int highest_FA);
int check_confirmed_data(struct bindingentry *binding,
			 struct msg_extensions *ext);
struct unconfirmed_request *
add_unconfirmed_data(struct bindingtable *bhash,
		     struct binding_counters *bcounters,
		     struct bindingentry *binding,
		     struct msg_extensions *ext,
		     struct packet_from_info *info,
		     struct fa_config *config);
void unconfirmed_to_binding(struct bindingentry *binding,
			    struct unconfirmed_request *unc);
void check_unconfirmed_timeout(struct bindingentry *binding);
void remove_binding_tunnels(struct bindingentry *binding,
			    struct hashtable *thash,
			    struct binding_counters *bcounters);
void check_bindings(struct bindingtable *bhash, struct hashtable *thash,
		    struct binding_counters *bcounters);
int is_sender_mobile(struct msg_extensions *ext);
int info_send(int type, int status, void *data, int len);
struct challenge_ext * create_challenge_ext(struct fa_config *config,
					    int type);
int equal_challenge(struct challenge_ext *c1, struct challenge_ext *c2);
void setup_device_forcing(struct tunnel_data *t_data);
int packet_socket_send(struct packet_from_info *dst, const unsigned char *msg,
		       int len);

#endif /* FA_H */