chan_sip.c

Asterisk中信道部分的源码 。。。。

/*! \brief Structure for SIP peer data, we place calls to peers if registered  or fixed IP address (host) */
/* XXX field 'name' must be first otherwise sip_addrcmp() will fail */
struct sip_peer {
	ASTOBJ_COMPONENTS(struct sip_peer);	/*!< name, refcount, objflags,  object pointers */
					/*!< peer->name is the unique name of this object */
	char secret[80];		/*!< Password */
	char md5secret[80];		/*!< Password in MD5 */
	struct sip_auth *auth;		/*!< Realm authentication list */
	char context[AST_MAX_CONTEXT];	/*!< Default context for incoming calls */
	char subscribecontext[AST_MAX_CONTEXT];	/*!< Default context for subscriptions */
	char username[80];		/*!< Temporary username until registration */ 
	char accountcode[AST_MAX_ACCOUNT_CODE];	/*!< Account code */
	int amaflags;			/*!< AMA Flags (for billing) */
	char tohost[MAXHOSTNAMELEN];	/*!< If not dynamic, IP address */
	char regexten[AST_MAX_EXTENSION]; /*!< Extension to register (if regcontext is used) */
	char fromuser[80];		/*!< From: user when calling this peer */
	char fromdomain[MAXHOSTNAMELEN];	/*!< From: domain when calling this peer */
	char fullcontact[256];		/*!< Contact registered with us (not in sip.conf) */
	char cid_num[80];		/*!< Caller ID num */
	char cid_name[80];		/*!< Caller ID name */
	int callingpres;		/*!< Calling id presentation */
	int inUse;			/*!< Number of calls in use */
	int inRinging;			/*!< Number of calls ringing */
	int onHold;                     /*!< Peer has someone on hold */
	int call_limit;			/*!< Limit of concurrent calls */
	enum transfermodes allowtransfer;	/*! SIP Refer restriction scheme */
	char vmexten[AST_MAX_EXTENSION]; /*!< Dialplan extension for MWI notify message*/
	char mailbox[AST_MAX_EXTENSION]; /*!< Mailbox setting for MWI checks */
	char language[MAX_LANGUAGE];	/*!<  Default language for prompts */
	char mohinterpret[MAX_MUSICCLASS];/*!<  Music on Hold class */
	char mohsuggest[MAX_MUSICCLASS];/*!<  Music on Hold class */
	char useragent[256];		/*!<  User agent in SIP request (saved from registration) */
	struct ast_codec_pref prefs;	/*!<  codec prefs */
	int lastmsgssent;
	time_t	lastmsgcheck;		/*!<  Last time we checked for MWI */
	unsigned int sipoptions;	/*!<  Supported SIP options */
	struct ast_flags flags[2];	/*!<  SIP_ flags */
	int expire;			/*!<  When to expire this peer registration */
	int capability;			/*!<  Codec capability */
	int rtptimeout;			/*!<  RTP timeout */
	int rtpholdtimeout;		/*!<  RTP Hold Timeout */
	int rtpkeepalive;		/*!<  Send RTP packets for keepalive */
	ast_group_t callgroup;		/*!<  Call group */
	ast_group_t pickupgroup;	/*!<  Pickup group */
	struct sockaddr_in addr;	/*!<  IP address of peer */
	int maxcallbitrate;		/*!< Maximum Bitrate for a video call */
	
	/* Qualification */
	struct sip_pvt *call;		/*!<  Call pointer */
	int pokeexpire;			/*!<  When to expire poke (qualify= checking) */
	int lastms;			/*!<  How long last response took (in ms), or -1 for no response */
	int maxms;			/*!<  Max ms we will accept for the host to be up, 0 to not monitor */
	struct timeval ps;		/*!<  Ping send time */
	
	struct sockaddr_in defaddr;	/*!<  Default IP address, used until registration */
	struct ast_ha *ha;		/*!<  Access control list */
	struct ast_variable *chanvars;	/*!<  Variables to set for channel created by user */
	struct sip_pvt *mwipvt;		/*!<  Subscription for MWI */
	int lastmsg;
	int autoframing;
};



/*! \brief Registrations with other SIP proxies */
struct sip_registry {
	ASTOBJ_COMPONENTS_FULL(struct sip_registry,1,1);
	AST_DECLARE_STRING_FIELDS(
		AST_STRING_FIELD(callid);	/*!< Global Call-ID */
		AST_STRING_FIELD(realm);	/*!< Authorization realm */
		AST_STRING_FIELD(nonce);	/*!< Authorization nonce */
		AST_STRING_FIELD(opaque);	/*!< Opaque nonsense */
		AST_STRING_FIELD(qop);		/*!< Quality of Protection, since SIP wasn't complicated enough yet. */
		AST_STRING_FIELD(domain);	/*!< Authorization domain */
		AST_STRING_FIELD(username);	/*!< Who we are registering as */
		AST_STRING_FIELD(authuser);	/*!< Who we *authenticate* as */
		AST_STRING_FIELD(hostname);	/*!< Domain or host we register to */
		AST_STRING_FIELD(secret);	/*!< Password in clear text */	
		AST_STRING_FIELD(md5secret);	/*!< Password in md5 */
		AST_STRING_FIELD(contact);	/*!< Contact extension */
		AST_STRING_FIELD(random);
	);
	int portno;			/*!<  Optional port override */
	int expire;			/*!< Sched ID of expiration */
	int regattempts;		/*!< Number of attempts (since the last success) */
	int timeout; 			/*!< sched id of sip_reg_timeout */
	int refresh;			/*!< How often to refresh */
	struct sip_pvt *call;		/*!< create a sip_pvt structure for each outbound "registration dialog" in progress */
	enum sipregistrystate regstate;	/*!< Registration state (see above) */
	time_t regtime;		/*!< Last succesful registration time */
	int callid_valid;		/*!< 0 means we haven't chosen callid for this registry yet. */
	unsigned int ocseq;		/*!< Sequence number we got to for REGISTERs for this registry */
	struct sockaddr_in us;		/*!< Who the server thinks we are */
	int noncecount;			/*!< Nonce-count */
	char lastmsg[256];		/*!< Last Message sent/received */
};

/* --- Linked lists of various objects --------*/

/*! \brief  The user list: Users and friends */
static struct ast_user_list {
	ASTOBJ_CONTAINER_COMPONENTS(struct sip_user);
} userl;

/*! \brief  The peer list: Peers and Friends */
static struct ast_peer_list {
	ASTOBJ_CONTAINER_COMPONENTS(struct sip_peer);
} peerl;

/*! \brief  The register list: Other SIP proxys we register with and place calls to */
static struct ast_register_list {
	ASTOBJ_CONTAINER_COMPONENTS(struct sip_registry);
	int recheck;
} regl;

static void temp_pvt_cleanup(void *);

/*! \brief A per-thread temporary pvt structure */
AST_THREADSTORAGE_CUSTOM(ts_temp_pvt, temp_pvt_init, temp_pvt_cleanup);

#ifdef LOW_MEMORY
static void ts_ast_rtp_destroy(void *);

AST_THREADSTORAGE_CUSTOM(ts_audio_rtp, ts_audio_rtp_init, ts_ast_rtp_destroy);
AST_THREADSTORAGE_CUSTOM(ts_video_rtp, ts_video_rtp_init, ts_ast_rtp_destroy);
#endif

/*! \todo Move the sip_auth list to AST_LIST */
static struct sip_auth *authl = NULL;		/*!< Authentication list for realm authentication */


/* --- Sockets and networking --------------*/
static int sipsock  = -1;			/*!< Main socket for SIP network communication */
static struct sockaddr_in bindaddr = { 0, };	/*!< The address we bind to */
static struct sockaddr_in externip;		/*!< External IP address if we are behind NAT */
static char externhost[MAXHOSTNAMELEN];		/*!< External host name (possibly with dynamic DNS and DHCP */
static time_t externexpire = 0;			/*!< Expiration counter for re-resolving external host name in dynamic DNS */
static int externrefresh = 10;
static struct ast_ha *localaddr;		/*!< List of local networks, on the same side of NAT as this Asterisk */
static struct in_addr __ourip;
static struct sockaddr_in outboundproxyip;
static int ourport;
static struct sockaddr_in debugaddr;

static struct ast_config *notify_types;		/*!< The list of manual NOTIFY types we know how to send */

/*---------------------------- Forward declarations of functions in chan_sip.c */
/*! \note This is added to help splitting up chan_sip.c into several files
	in coming releases */

/*--- PBX interface functions */
static struct ast_channel *sip_request_call(const char *type, int format, void *data, int *cause);
static int sip_devicestate(void *data);
static int sip_sendtext(struct ast_channel *ast, const char *text);
static int sip_call(struct ast_channel *ast, char *dest, int timeout);
static int sip_hangup(struct ast_channel *ast);
static int sip_answer(struct ast_channel *ast);
static struct ast_frame *sip_read(struct ast_channel *ast);
static int sip_write(struct ast_channel *ast, struct ast_frame *frame);
static int sip_indicate(struct ast_channel *ast, int condition, const void *data, size_t datalen);
static int sip_transfer(struct ast_channel *ast, const char *dest);
static int sip_fixup(struct ast_channel *oldchan, struct ast_channel *newchan);
static int sip_senddigit_begin(struct ast_channel *ast, char digit);
static int sip_senddigit_end(struct ast_channel *ast, char digit, unsigned int duration);

/*--- Transmitting responses and requests */
static int sipsock_read(int *id, int fd, short events, void *ignore);
static int __sip_xmit(struct sip_pvt *p, char *data, int len);
static int __sip_reliable_xmit(struct sip_pvt *p, int seqno, int resp, char *data, int len, int fatal, int sipmethod);
static int __transmit_response(struct sip_pvt *p, const char *msg, const struct sip_request *req, enum xmittype reliable);
static int retrans_pkt(const void *data);
static int transmit_sip_request(struct sip_pvt *p, struct sip_request *req);
static int transmit_response_using_temp(ast_string_field callid, struct sockaddr_in *sin, int useglobal_nat, const int intended_method, const struct sip_request *req, const char *msg);
static int transmit_response(struct sip_pvt *p, const char *msg, const struct sip_request *req);
static int transmit_response_reliable(struct sip_pvt *p, const char *msg, const struct sip_request *req);
static int transmit_response_with_date(struct sip_pvt *p, const char *msg, const struct sip_request *req);
static int transmit_response_with_sdp(struct sip_pvt *p, const char *msg, const struct sip_request *req, enum xmittype reliable);
static int transmit_response_with_unsupported(struct sip_pvt *p, const char *msg, const struct sip_request *req, const char *unsupported);
static int transmit_response_with_auth(struct sip_pvt *p, const char *msg, const struct sip_request *req, const char *rand, enum xmittype reliable, const char *header, int stale);
static int transmit_response_with_allow(struct sip_pvt *p, const char *msg, const struct sip_request *req, enum xmittype reliable);
static void transmit_fake_auth_response(struct sip_pvt *p, struct sip_request *req, int reliable);
static int transmit_request(struct sip_pvt *p, int sipmethod, int inc, enum xmittype reliable, int newbranch);
static int transmit_request_with_auth(struct sip_pvt *p, int sipmethod, int seqno, enum xmittype reliable, int newbranch);
static int transmit_invite(struct sip_pvt *p, int sipmethod, int sdp, int init);
static int transmit_reinvite_with_sdp(struct sip_pvt *p);
static int transmit_info_with_digit(struct sip_pvt *p, const char digit, unsigned int duration);
static int transmit_info_with_vidupdate(struct sip_pvt *p);
static int transmit_message_with_text(struct sip_pvt *p, const char *text);
static int transmit_refer(struct sip_pvt *p, const char *dest);
static int transmit_notify_with_mwi(struct sip_pvt *p, int newmsgs, int oldmsgs, char *vmexten);
static int transmit_notify_with_sipfrag(struct sip_pvt *p, int cseq, char *message, int terminate);
static int transmit_register(struct sip_registry *r, int sipmethod, const char *auth, const char *authheader);
static int send_response(struct sip_pvt *p, struct sip_request *req, enum xmittype reliable, int seqno);
static int send_request(struct sip_pvt *p, struct sip_request *req, enum xmittype reliable, int seqno);
static void copy_request(struct sip_request *dst, const struct sip_request *src);
static void receive_message(struct sip_pvt *p, struct sip_request *req);
static void parse_moved_contact(struct sip_pvt *p, struct sip_request *req);
static int sip_send_mwi_to_peer(struct sip_peer *peer);
static int does_peer_need_mwi(struct sip_peer *peer);

/*--- Dialog management */
static struct sip_pvt *sip_alloc(ast_string_field callid, struct sockaddr_in *sin,
				 int useglobal_nat, const int intended_method);
static int __sip_autodestruct(const void *data);
static void sip_scheddestroy(struct sip_pvt *p, int ms);
static int sip_cancel_destroy(struct sip_pvt *p);
static void sip_destroy(struct sip_pvt *p);
static int __sip_destroy(struct sip_pvt *p, int lockowner);
static void __sip_ack(struct sip_pvt *p, int seqno, int resp, int sipmethod);
static void __sip_pretend_ack(struct sip_pvt *p);
static int __sip_semi_ack(struct sip_pvt *p, int seqno, int resp, int sipmethod);
static int auto_congest(const void *nothing);
static int update_call_counter(struct sip_pvt *fup, int event);
static int hangup_sip2cause(int cause);
static const char *hangup_cause2sip(int cause);
static struct sip_pvt *find_call(struct sip_request *req, struct sockaddr_in *sin, const int intended_method);
static void free_old_route(struct sip_route *route);
static void list_route(struct sip_route *route);
static void build_route(struct sip_pvt *p, struct sip_request *req, int backwards);
static enum check_auth_result register_verify(struct sip_pvt *p, struct sockaddr_in *sin,
					      struct sip_request *req, char *uri);
static struct sip_pvt *get_sip_pvt_byid_locked(const char *callid, const char *totag, const char *fromtag);
static void check_pendings(struct sip_pvt *p);
static void *sip_park_thread(void *stuff);
static int sip_park(struct ast_channel *chan1, struct ast_channel *chan2, struct sip_request *req, int seqno);
static int sip_sipredirect(struct sip_pvt *p, const char *dest);

/*--- Codec handling / SDP */
static void try_suggested_sip_codec(struct sip_pvt *p);
static const char* get_sdp_iterate(int* start, struct sip_request *req, const char *name);
static const char *get_sdp(struct sip_request *req, const char *name);
static int find_sdp(struct sip_request *req);
static int process_sdp(struct sip_pvt *p, struct sip_request *req);
static void add_codec_to_sdp(const struct sip_pvt *p, int codec, int sample_rate,
			     char **m_buf, size_t *m_size, char **a_buf, size_t *a_size,
			     int debug, int *min_packet_size);
static void add_noncodec_to_sdp(const struct sip_pvt *p, int format, int sample_rate,
				char **m_buf, size_t *m_size, char **a_buf, size_t *a_size,
				int debug);
static enum sip_result add_sdp(struct sip_request *resp, struct sip_pvt *p);
static void stop_media_flows(struct sip_pvt *p);

/*--- Authentication stuff */
static int reply_digest(struct sip_pvt *p, struct sip_request *req, char *header, int sipmethod, char *digest, int digest_len);
static int build_reply_digest(struct sip_pvt *p, int method, char *digest, int digest_len);
static enum check_auth_result check_auth(struct sip_pvt *p, struct sip_request *req, const char *username,
					 const char *secret, const char *md5secret, int sipmethod,
					 char *uri, enum xmittype reliable, int ignore);
static enum check_auth_result check_user_full(struct sip_pvt *p, struct sip_request *req,
					      int sipmethod, char *uri, enum xmittype reliable,
					      struct sockaddr_in *sin, struct sip_peer **authpeer);
static int check_user(struct sip_pvt *p, struct sip_request *req, int sipmethod, char *uri, enum xmittype reliable, struct sockaddr_in *sin);

/*--- Domain handling */
static int check_sip_domain(const char *domain, char *context, size_t len); /* Check if domain is one of our local domains */
static int add_sip_domain(const char *domain, const enum domain_mode mode, const char *context);
static void clear_sip_domains(void);

/*--- SIP realm authentication */
static struct sip_auth *add_realm_authentication(struct sip_auth *authlist, char *configuration, int lineno);
static int clear_realm_authentication(struct sip_auth *authlist);	/* Clear realm authentication list (at reload) */
static struct sip_auth *find_realm_authentication(struct sip_auth *authlist, const char *realm);

/*--- Misc functions */
static int sip_do_reload(enum channelreloadreason reason);
static int reload_config(enum channelreloadreason reason);
static int expire_register(const void *data