misc.c

/*
linphone
Copyright (C) 2000  Simon MORLAT (simon.morlat@linphone.org)

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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
*/

#include "private.h"
#include "lpconfig.h"
#include "mediastreamer2/mediastream.h"
#include <stdlib.h>
#include <stdio.h>
#ifdef HAVE_SIGHANDLER_T
#include <signal.h>
#endif /*HAVE_SIGHANDLER_T*/

#include <string.h>
#if !defined(_WIN32_WCE)
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#if _MSC_VER
#include <io.h>
#else
#include <unistd.h>
#endif
#include <fcntl.h>
#endif /*_WIN32_WCE*/

#undef snprintf
#include <mediastreamer2/stun.h>

#ifdef HAVE_GETIFADDRS
#include <net/if.h>
#include <ifaddrs.h>
#endif
#include <math.h>
#if _MSC_VER
#define snprintf _snprintf
#define popen _popen
#define pclose _pclose
#endif


#define UDP_HDR_SZ 8
#define RTP_HDR_SZ 12
#define IP4_HDR_SZ 20   /*20 is the minimum, but there may be some options*/

static void clear_ice_check_list(LinphoneCall *call, IceCheckList *removed);

bool_t linphone_core_payload_type_enabled(LinphoneCore *lc, const LinphonePayloadType *pt){
	if (bctbx_list_find(lc->codecs_conf.audio_codecs, (PayloadType*) pt) || bctbx_list_find(lc->codecs_conf.video_codecs, (PayloadType*)pt) || bctbx_list_find(lc->codecs_conf.text_codecs, (PayloadType*)pt)){
		return payload_type_enabled(pt);
	}
	ms_error("Getting enablement status of codec not in audio or video list of PayloadType !");
	return FALSE;
}

bool_t linphone_core_payload_type_is_vbr(LinphoneCore *lc, const LinphonePayloadType *pt){
	if (pt->type==PAYLOAD_VIDEO) return TRUE;
	return !!(pt->flags & PAYLOAD_TYPE_IS_VBR);
}

int linphone_core_enable_payload_type(LinphoneCore *lc, LinphonePayloadType *pt, bool_t enabled){
	if (bctbx_list_find(lc->codecs_conf.audio_codecs,pt) || bctbx_list_find(lc->codecs_conf.video_codecs,pt) || bctbx_list_find(lc->codecs_conf.text_codecs,pt)){
		payload_type_set_enable(pt,enabled);
		_linphone_core_codec_config_write(lc);
		linphone_core_update_allocated_audio_bandwidth(lc);
		return 0;
	}
	ms_error("Enabling codec not in audio or video list of PayloadType !");
	return -1;
}

int linphone_core_get_payload_type_number(LinphoneCore *lc, const PayloadType *pt){
	return payload_type_get_number(pt);
}

void linphone_core_set_payload_type_number(LinphoneCore *lc, PayloadType *pt, int number){
	payload_type_set_number(pt,number);
}

const char *linphone_core_get_payload_type_description(LinphoneCore *lc, PayloadType *pt){
	//if (ms_filter_codec_supported(pt->mime_type)){
	if (ms_factory_codec_supported(lc->factory, pt->mime_type)){
		MSFilterDesc *desc=ms_factory_get_encoder(lc->factory, pt->mime_type);
#ifdef ENABLE_NLS
		return dgettext("mediastreamer",desc->text);
#else
		return desc->text;
#endif
	}
	return NULL;
}

void linphone_core_set_payload_type_bitrate(LinphoneCore *lc, LinphonePayloadType *pt, int bitrate){
	if (bctbx_list_find(lc->codecs_conf.audio_codecs, (PayloadType*) pt) || bctbx_list_find(lc->codecs_conf.video_codecs, (PayloadType*)pt) || bctbx_list_find(lc->codecs_conf.text_codecs, (PayloadType*)pt)){
		if (pt->type==PAYLOAD_VIDEO || pt->flags & PAYLOAD_TYPE_IS_VBR){
			pt->normal_bitrate=bitrate*1000;
			pt->flags|=PAYLOAD_TYPE_BITRATE_OVERRIDE;
			linphone_core_update_allocated_audio_bandwidth(lc);
		}else{
			ms_error("Cannot set an explicit bitrate for codec %s/%i, because it is not VBR.",pt->mime_type,pt->clock_rate);
			return;
		}
	} else {
		ms_error("linphone_core_set_payload_type_bitrate() payload type not in audio or video list !");
	}
}


/*
 *((codec-birate*ptime/8) + RTP header + UDP header + IP header)*8/ptime;
 *ptime=1/npacket
 */

static double get_audio_payload_bandwidth_from_codec_bitrate(const PayloadType *pt){
	double npacket=50;
	double packet_size;
	int bitrate;

	if (strcmp(payload_type_get_mime(&payload_type_aaceld_44k), payload_type_get_mime(pt))==0) {
		/*special case of aac 44K because ptime= 10ms*/
		npacket=100;
	}else if (strcmp(payload_type_get_mime(&payload_type_ilbc), payload_type_get_mime(pt))==0) {
		npacket=1000/30.0;
	}

	bitrate=pt->normal_bitrate;
	packet_size= (((double)bitrate)/(npacket*8))+UDP_HDR_SZ+RTP_HDR_SZ+IP4_HDR_SZ;
	return packet_size*8.0*npacket;
}

typedef struct vbr_codec_bitrate{
	int max_avail_bitrate;
	int min_rate;
	int recomended_bitrate;
}vbr_codec_bitrate_t;

static vbr_codec_bitrate_t defauls_vbr[]={
	//{ 100, 44100, 100 },
	{ 64, 44100, 50 },
	{ 64, 16000, 40 },
	{ 32, 16000, 32 },
	{ 32, 8000, 32 },
	{ 0 , 8000, 24 },
	{ 0 , 0, 0 }
};

static int lookup_vbr_typical_bitrate(int maxbw, int clock_rate){
	vbr_codec_bitrate_t *it;
	if (maxbw<=0) maxbw=defauls_vbr[0].max_avail_bitrate;
	for(it=defauls_vbr;it->min_rate!=0;it++){
		if (maxbw>=it->max_avail_bitrate && clock_rate>=it->min_rate)
			return it->recomended_bitrate;
	}
	ms_error("lookup_vbr_typical_bitrate(): should not happen.");
	return 32;
}

static int get_audio_payload_bandwidth(LinphoneCore *lc, const PayloadType *pt, int maxbw){
	if (linphone_core_payload_type_is_vbr(lc,pt)){
		if (pt->flags & PAYLOAD_TYPE_BITRATE_OVERRIDE){
			ms_debug("PayloadType %s/%i has bitrate override",pt->mime_type,pt->clock_rate);
			return pt->normal_bitrate/1000;
		}
		return lookup_vbr_typical_bitrate(maxbw,pt->clock_rate);
	}else return (int)ceil(get_audio_payload_bandwidth_from_codec_bitrate(pt)/1000.0);/*rounding codec bandwidth should be avoid, specially for AMR*/
}

int linphone_core_get_payload_type_bitrate(LinphoneCore *lc, const LinphonePayloadType *pt){
	int maxbw=get_min_bandwidth(linphone_core_get_download_bandwidth(lc),
					linphone_core_get_upload_bandwidth(lc));
	if (pt->type==PAYLOAD_AUDIO_CONTINUOUS || pt->type==PAYLOAD_AUDIO_PACKETIZED){
		return get_audio_payload_bandwidth(lc,pt,maxbw);
	}else if (pt->type==PAYLOAD_VIDEO){
		int video_bw;
		if (maxbw<=0) {
			video_bw=1500; /*default bitrate for video stream when no bandwidth limit is set, around 1.5 Mbit/s*/
		}else{
			video_bw=get_remaining_bandwidth_for_video(maxbw,lc->audio_bw);
		}
		return video_bw;
	}
	return 0;
}

void linphone_core_update_allocated_audio_bandwidth_in_call(LinphoneCall *call, const PayloadType *pt, int maxbw){
	call->audio_bw=get_audio_payload_bandwidth(call->core,pt,maxbw);
	ms_message("Audio bandwidth for this call is %i",call->audio_bw);
}

void linphone_core_update_allocated_audio_bandwidth(LinphoneCore *lc){
	const bctbx_list_t *elem;
	int maxbw=get_min_bandwidth(linphone_core_get_download_bandwidth(lc),
					linphone_core_get_upload_bandwidth(lc));
	int max_codec_bitrate=0;

	for(elem=linphone_core_get_audio_codecs(lc);elem!=NULL;elem=elem->next){
		PayloadType *pt=(PayloadType*)elem->data;
		if (payload_type_enabled(pt)){
			int pt_bitrate=get_audio_payload_bandwidth(lc,pt,maxbw);
			if (max_codec_bitrate==0) {
				max_codec_bitrate=pt_bitrate;
			}else if (max_codec_bitrate<pt_bitrate){
				max_codec_bitrate=pt_bitrate;
			}
		}
	}
	if (max_codec_bitrate) {
		lc->audio_bw=max_codec_bitrate;
	}
}

bool_t linphone_core_is_payload_type_usable_for_bandwidth(LinphoneCore *lc, const PayloadType *pt, int bandwidth_limit){
	double codec_band;
	const int video_enablement_limit = 99;
	bool_t ret=FALSE;

	switch (pt->type){
		case PAYLOAD_AUDIO_CONTINUOUS:
		case PAYLOAD_AUDIO_PACKETIZED:
			codec_band=get_audio_payload_bandwidth(lc,pt,bandwidth_limit);
			ret=bandwidth_is_greater(bandwidth_limit,(int)codec_band);
			/*ms_message("Payload %s: codec_bandwidth=%g, bandwidth_limit=%i",pt->mime_type,codec_band,bandwidth_limit);*/
			break;
		case PAYLOAD_VIDEO:
			if (bandwidth_limit<=0 || bandwidth_limit >= video_enablement_limit) {/* infinite or greater than video_enablement_limit*/
				ret=TRUE;
			}
			else ret=FALSE;
			break;
		case PAYLOAD_TEXT:
			ret=TRUE;
			break;
	}
	return ret;
}

/* return TRUE if codec can be used with bandwidth, FALSE else*/
bool_t linphone_core_check_payload_type_usability(LinphoneCore *lc, const PayloadType *pt){
	int maxbw=get_min_bandwidth(linphone_core_get_download_bandwidth(lc),
					linphone_core_get_upload_bandwidth(lc));
	bool_t ret=linphone_core_is_payload_type_usable_for_bandwidth(lc, pt, maxbw);
	if ((pt->type==PAYLOAD_AUDIO_CONTINUOUS || pt->type==PAYLOAD_AUDIO_PACKETIZED)
		&& lc->sound_conf.capt_sndcard
		&& !(ms_snd_card_get_capabilities(lc->sound_conf.capt_sndcard) & MS_SND_CARD_CAP_BUILTIN_ECHO_CANCELLER)
		&& linphone_core_echo_cancellation_enabled(lc)
		&& (pt->clock_rate!=16000 && pt->clock_rate!=8000)
		&& strcasecmp(pt->mime_type,"opus")!=0
		&& ms_factory_lookup_filter_by_name(lc->factory, "MSWebRTCAEC")!=NULL){
		ms_warning("Payload type %s/%i cannot be used because software echo cancellation is required but is unable to operate at this rate.",
			   pt->mime_type,pt->clock_rate);
		ret=FALSE;
	}
	return ret;
}

bool_t lp_spawn_command_line_sync(const char *command, char **result,int *command_ret){
#if !defined(_WIN32_WCE) && !defined(LINPHONE_WINDOWS_UNIVERSAL)
	FILE *f=popen(command,"r");
	if (f!=NULL){
		int err;
		*result=ms_malloc(4096);
		err=fread(*result,1,4096-1,f);
		if (err<0){
			ms_warning("Error reading command output:%s",strerror(errno));
			ms_free(result);
			return FALSE;
		}
		(*result)[err]=0;
		err=pclose(f);
		if (command_ret!=NULL) *command_ret=err;
		return TRUE;
	}
#endif /*_WIN32_WCE*/
	return FALSE;
}

static ortp_socket_t create_socket(int local_port){
	struct sockaddr_in laddr;
	ortp_socket_t sock;
	int optval;
	sock=socket(PF_INET,SOCK_DGRAM,IPPROTO_UDP);
	if (sock<0) {
		ms_error("Fail to create socket");
		return -1;
	}
	memset (&laddr,0,sizeof(laddr));
	laddr.sin_family=AF_INET;
	laddr.sin_addr.s_addr=INADDR_ANY;
	laddr.sin_port=htons(local_port);
	if (bind(sock,(struct sockaddr*)&laddr,sizeof(laddr))<0){
		ms_error("Bind socket to 0.0.0.0:%i failed: %s",local_port,getSocketError());
		close_socket(sock);
		return -1;
	}
	optval=1;
	if (setsockopt (sock, SOL_SOCKET, SO_REUSEADDR,
				(SOCKET_OPTION_VALUE)&optval, sizeof (optval))<0){
		ms_warning("Fail to set SO_REUSEADDR");
	}
	set_non_blocking_socket(sock);
	return sock;
}

static int send_stun_request(int sock, const struct sockaddr *server, socklen_t addrlen, int id, bool_t change_addr){
	char *buf = NULL;
	size_t len;
	int err = 0;
	MSStunMessage *req = ms_stun_binding_request_create();
	UInt96 tr_id = ms_stun_message_get_tr_id(req);
	tr_id.octet[0] = id;
	ms_stun_message_set_tr_id(req, tr_id);
	ms_stun_message_enable_change_ip(req, change_addr);
	ms_stun_message_enable_change_port(req, change_addr);
	len = ms_stun_message_encode(req, &buf);
	if (len <= 0) {
		ms_error("Fail to encode stun message.");
		err = -1;
	} else {
		err = bctbx_sendto(sock, buf, len, 0, server, addrlen);
		if (err < 0) {
			ms_error("sendto failed: %s",strerror(errno));
			err = -1;
		}
	}
	if (buf != NULL) ms_free(buf);
	ms_free(req);
	return err;
}

int linphone_parse_host_port(const char *input, char *host, size_t hostlen, int *port){
	char tmphost[NI_MAXHOST]={0};
	char *p1, *p2;

	if ((sscanf(input, "[%64[^]]]:%d", tmphost, port) == 2) || (sscanf(input, "[%64[^]]]", tmphost) == 1)) {

	} else {
		p1 = strchr(input, ':');
		p2 = strrchr(input, ':');
		if (p1 && p2 && (p1 != p2)) {/* an ipv6 address without port*/
			strncpy(tmphost, input, sizeof(tmphost) - 1);
		} else if (sscanf(input, "%[^:]:%d", tmphost, port) != 2) {
			/*no port*/
			strncpy(tmphost, input, sizeof(tmphost) - 1);
		}
	}
	strncpy(host,tmphost,hostlen);
	return 0;
}

int parse_hostname_to_addr(const char *server, struct sockaddr_storage *ss, socklen_t *socklen, int default_port){
	struct addrinfo hints,*res=NULL;
	char port[6];
	char host[NI_MAXHOST];
	int port_int=default_port;
	int ret;

	linphone_parse_host_port(server,host,sizeof(host),&port_int);

	snprintf(port, sizeof(port), "%d", port_int);
	memset(&hints,0,sizeof(hints));
	hints.ai_family=AF_UNSPEC;
	hints.ai_socktype=SOCK_DGRAM;
	hints.ai_protocol=IPPROTO_UDP;
	ret=getaddrinfo(host,port,&hints,&res);
	if (ret!=0){
		ms_error("getaddrinfo() failed for %s:%s : %s",host,port,gai_strerror(ret));
		return -1;
	}
	if (!res) return -1;
	memcpy(ss,res->ai_addr,res->ai_addrlen);
	*socklen=(socklen_t)res->ai_addrlen;
	freeaddrinfo(res);
	return 0;
}

static int recv_stun_response(ortp_socket_t sock, char *ipaddr, int *port, int *id) {
	char buf[MS_STUN_MAX_MESSAGE_SIZE];
	int len = MS_STUN_MAX_MESSAGE_SIZE;
	MSStunMessage *resp;

	len = recv(sock, buf, len, 0);
	if (len > 0) {
		struct in_addr ia;
		resp = ms_stun_message_create_from_buffer_parsing((uint8_t *)buf, (ssize_t)len);
		if (resp != NULL) {
			const MSStunAddress *stun_addr;
			UInt96 tr_id = ms_stun_message_get_tr_id(resp);
			*id = tr_id.octet[0];
			stun_addr = ms_stun_message_get_xor_mapped_address(resp);
			if (stun_addr != NULL) {
				*port = stun_addr->ip.v4.port;
				ia.s_addr = htonl(stun_addr->ip.v4.addr);
			} else {
				stun_addr = ms_stun_message_get_mapped_address(resp);
				if (stun_addr != NULL) {
					*port = stun_addr->ip.v4.port;
					ia.s_addr = htonl(stun_addr->ip.v4.addr);
				} else len = -1;
			}
			if (len > 0) strncpy(ipaddr, inet_ntoa(ia), LINPHONE_IPADDR_SIZE);
		}
	}
	return len;
}

/* this functions runs a simple stun test and return the number of milliseconds to complete the tests, or -1 if the test were failed.*/
int linphone_core_run_stun_tests(LinphoneCore *lc, LinphoneCall *call){
	const char *server=linphone_core_get_stun_server(lc);
	StunCandidate *ac=&call->ac;
	StunCandidate *vc=&call->vc;
	StunCandidate *tc=&call->tc;

	if (lc->sip_conf.ipv6_enabled){
		ms_warning("stun support is not implemented for ipv6");
		return -1;
	}
	if (call->media_ports[call->main_audio_stream_index].rtp_port==-1){
		ms_warning("Stun-only support not available for system random port");
		return -1;
	}
	if (server!=NULL){
		const struct addrinfo *ai=linphone_core_get_stun_server_addrinfo(lc);
		ortp_socket_t sock1=-1, sock2=-1, sock3=-1;
		int loops=0;
		bool_t video_enabled=linphone_core_video_enabled(lc);
		bool_t got_audio,got_video,got_text;
		bool_t cone_audio=FALSE,cone_video=FALSE,cone_text=FALSE;
		struct timeval init,cur;
		double elapsed;
		int ret=0;

		if (ai==NULL){
			ms_error("Could not obtain stun server addrinfo.");
			return -1;
		}
		linphone_core_notify_display_status(lc,_("Stun lookup in progress..."));

		/*create the two audio and video RTP sockets, and send STUN message to our stun server */
		sock1=create_socket(call->media_ports[call->main_audio_stream_index].rtp_port);
		if (sock1==-1) return -1;
		if (video_enabled){
			sock2=create_socket(call->media_ports[call->main_video_stream_index].rtp_port);
			if (sock2==-1) return -1;
		}
		sock3=create_socket(call->media_ports[call->main_text_stream_index].rtp_port);
		if (sock3==-1) return -1;
		
		got_audio=FALSE;
		got_video=FALSE;
		got_text=FALSE;
		ortp_gettimeofday(&init,NULL);
		do{

			int id;
			if (loops%20==0){
				ms_message("Sending stun requests...");
				send_stun_request((int)sock1,ai->ai_addr,(socklen_t)ai->ai_addrlen,11,TRUE);
				send_stun_request((int)sock1,ai->ai_addr,(socklen_t)ai->ai_addrlen,1,FALSE);
				if (sock2!=-1){
					send_stun_request((int)sock2,ai->ai_addr,(socklen_t)ai->ai_addrlen,22,TRUE);
					send_stun_request((int)sock2,ai->ai_addr,(socklen_t)ai->ai_addrlen,2,FALSE);
				}
				if (sock3!=-1){
					send_stun_request((int)sock3,ai->ai_addr,(socklen_t)ai->ai_addrlen,33,TRUE);
					send_stun_request((int)sock3,ai->ai_addr,(socklen_t)ai->ai_addrlen,3,FALSE);
				}
			}
			ms_usleep(10000);

			if (recv_stun_response(sock1, ac->addr, &ac->port, &id) > 0) {
				ms_message("STUN test result: local audio port maps to %s:%i", ac->addr, ac->port);
				if (id==11) cone_audio=TRUE;
				got_audio=TRUE;
			}
			if (recv_stun_response(sock2, vc->addr, &vc->port, &id) > 0) {
				ms_message("STUN test result: local video port maps to %s:%i", vc->addr, vc->port);
				if (id==22) cone_video=TRUE;
				got_video=TRUE;
			}
			if (recv_stun_response(sock3, tc->addr, &tc->port, &id)>0) {
				ms_message("STUN test result: local text port maps to %s:%i", tc->addr, tc->port);
				if (id==33) cone_text=TRUE;
				got_text=TRUE;
			}
			ortp_gettimeofday(&cur,NULL);
			elapsed=((cur.tv_sec-init.tv_sec)*1000.0) +  ((cur.tv_usec-init.tv_usec)/1000.0);
			if (elapsed>2000)  {
				ms_message("Stun responses timeout, going ahead.");
				ret=-1;
				break;
			}
			loops++;
		}while(!(got_audio && (got_video||sock2==-1) && (got_text||sock3==-1)  ) );
		if (ret==0) ret=(int)elapsed;
		if (!got_audio){
			ms_error("No stun server response for audio port.");
		}else{
			if (!cone_audio) {
				ms_message("NAT is symmetric for audio port");
			}
		}
		if (sock2!=-1){
			if (!got_video){
				ms_error("No stun server response for video port.");
			}else{
				if (!cone_video) {
					ms_message("NAT is symmetric for video port.");
				}
			}
		}
		if (sock3!=-1){
			if (!got_text){
				ms_error("No stun server response for text port.");
			}else{
				if (!cone_text) {
					ms_message("NAT is symmetric for text port.");
				}
			}
		}
		close_socket(sock1);
		if (sock2!=-1) close_socket(sock2);
		if (sock3!=-1) close_socket(sock3);
		return ret;
	}
	return -1;
}

int linphone_core_get_edge_bw(LinphoneCore *lc){
	int edge_bw=lp_config_get_int(lc->config,"net","edge_bw",20);
	return edge_bw;
}

int linphone_core_get_edge_ptime(LinphoneCore *lc){
	int edge_ptime=lp_config_get_int(lc->config,"net","edge_ptime",100);
	return edge_ptime;
}

void linphone_core_adapt_to_network(LinphoneCore *lc, int ping_time_ms, LinphoneCallParams *params){
	int threshold;
	if (ping_time_ms>0 && lp_config_get_int(lc->config,"net","activate_edge_workarounds",0)==1){
		ms_message("Stun server ping time is %i ms",ping_time_ms);
		threshold=lp_config_get_int(lc->config,"net","edge_ping_time",500);

		if (ping_time_ms>threshold){
			/* we might be in a 2G network*/
			params->low_bandwidth=TRUE;
		}/*else use default settings */
	}
	if (params->low_bandwidth){
		params->up_bw=params->down_bw=linphone_core_get_edge_bw(lc);
		params->up_ptime=params->down_ptime=linphone_core_get_edge_ptime(lc);
		params->has_video=FALSE;
	}
}

static void stun_server_resolved(LinphoneCore *lc, const char *name, struct addrinfo *addrinfo){
	if (lc->net_conf.stun_addrinfo){
		bctbx_freeaddrinfo(lc->net_conf.stun_addrinfo);
		lc->net_conf.stun_addrinfo=NULL;
	}
	if (addrinfo){
		ms_message("Stun server resolution successful.");
	}else{
		ms_warning("Stun server resolution failed.");
	}
	lc->net_conf.stun_addrinfo=addrinfo;
	lc->net_conf.stun_res=NULL;
}

void linphone_core_resolve_stun_server(LinphoneCore *lc){
	if (lc->nat_policy != NULL) {
		linphone_nat_policy_resolve_stun_server(lc->nat_policy);
	} else {
		/*
		* WARNING: stun server resolution only done in IPv4.
		* TODO: use IPv6 resolution if linphone_core_ipv6_enabled()==TRUE and use V4Mapped addresses for ICE gathering.
		*/
		const char *server=linphone_core_get_stun_server(lc);
		if (lc->sal && server && !lc->net_conf.stun_res){
			char host[NI_MAXHOST];
			int port=3478;
			linphone_parse_host_port(server,host,sizeof(host),&port);
			lc->net_conf.stun_res=sal_resolve_a(lc->sal,host,port,AF_INET,(SalResolverCallback)stun_server_resolved,lc);
		}
	}
}

/*
 * This function returns the addrinfo representation of the stun server address.
 * It is critical not to block for a long time if it can't be resolved, otherwise this stucks the main thread when making a call.
 * On the contrary, a fully asynchronous call initiation is complex to develop.
 * The compromise is then:
 * - have a cache of the stun server addrinfo
 * - this cached value is returned when it is non-null
 * - an asynchronous resolution is asked each time this function is called to ensure frequent refreshes of the cached value.
 * - if no cached value exists, block for a short time; this case must be unprobable because the resolution will be asked each time the stun server value is
 * changed.
**/
const struct addrinfo *linphone_core_get_stun_server_addrinfo(LinphoneCore *lc){
	if (lc->nat_policy != NULL) {
		return linphone_nat_policy_get_stun_server_addrinfo(lc->nat_policy);
	} else {
		const char *server=linphone_core_get_stun_server(lc);
		if (server){
			int wait_ms=0;
			int wait_limit=1000;
			linphone_core_resolve_stun_server(lc);
			while (!lc->net_conf.stun_addrinfo && lc->net_conf.stun_res!=NULL && wait_ms<wait_limit){
				sal_iterate(lc->sal);
				ms_usleep(50000);
				wait_ms+=50;
			}
		}
		return lc->net_conf.stun_addrinfo;
	}
}

void linphone_core_enable_forced_ice_relay(LinphoneCore *lc, bool_t enable) {
	lc->forced_ice_relay = enable;
}

void linphone_core_enable_short_turn_refresh(LinphoneCore *lc, bool_t enable) {
	lc->short_turn_refresh = enable;
}

static void stun_auth_requested_cb(LinphoneCall *call, const char *realm, const char *nonce, const char **username, const char **password, const char **ha1) {
	LinphoneProxyConfig *proxy = NULL;
	const LinphoneNatPolicy *nat_policy = NULL;
	const LinphoneAddress *addr = NULL;
	const LinphoneAuthInfo *auth_info = NULL;
	LinphoneCore *lc = call->core;
	const char *user = NULL;

	// Get the username from the nat policy or the proxy config
	if (call->dest_proxy != NULL) proxy = call->dest_proxy;
	else proxy = linphone_core_get_default_proxy_config(call->core);
	if (proxy == NULL) return;
	nat_policy = linphone_proxy_config_get_nat_policy(proxy);
	if (nat_policy != NULL) {
		user = linphone_nat_policy_get_stun_server_username(nat_policy);
	} else {
		nat_policy = linphone_core_get_nat_policy(call->core);
		if (nat_policy != NULL) {
			user = linphone_nat_policy_get_stun_server_username(nat_policy);
		}
	}
	if (user == NULL) {
		/* If the username has not been found in the nat_policy, take the username from the currently used proxy config. */
		addr = linphone_proxy_config_get_identity_address(proxy);
		if (addr == NULL) return;
		user = linphone_address_get_username(addr);
	}
	if (user == NULL) return;

	auth_info = linphone_core_find_auth_info(lc, realm, user, NULL);
	if (auth_info != NULL) {
		const char *hash = linphone_auth_info_get_ha1(auth_info);
		if (hash != NULL) {
			*ha1 = hash;
		} else {
			*password = linphone_auth_info_get_passwd(auth_info);
		}
		*username = user;
	} else {
		ms_warning("No auth info found for STUN auth request");
	}
}

int linphone_core_gather_ice_candidates(LinphoneCore *lc, LinphoneCall *call){
	char local_addr[64];
	const struct addrinfo *ai = NULL;
	IceCheckList *audio_check_list;
	IceCheckList *video_check_list;
	IceCheckList *text_check_list;
	LinphoneNatPolicy *nat_policy = NULL;
	const char *server = NULL;

	if (call->dest_proxy != NULL) nat_policy = linphone_proxy_config_get_nat_policy(call->dest_proxy);
	if (nat_policy == NULL) nat_policy = linphone_core_get_nat_policy(lc);
	if (nat_policy != NULL) server = linphone_nat_policy_get_stun_server(nat_policy);

	if (call->ice_session == NULL) return -1;
	audio_check_list = ice_session_check_list(call->ice_session, call->main_audio_stream_index);
	video_check_list = ice_session_check_list(call->ice_session, call->main_video_stream_index);
	text_check_list = ice_session_check_list(call->ice_session, call->main_text_stream_index);
	if (audio_check_list == NULL) return -1;

	if (call->af==AF_INET6){
		ms_warning("Ice gathering is not implemented for ipv6");
		return -1;
	}
	if ((nat_policy != NULL) && (server != NULL) && (server[0] != '\0')) {
		ai=linphone_nat_policy_get_stun_server_addrinfo(nat_policy);
		if (ai==NULL){
			ms_warning("Fail to resolve STUN server for ICE gathering, continuing without stun.");
		}
	}else{
		ms_warning("Ice is used without stun server.");
	}
	linphone_core_notify_display_status(lc, _("ICE local candidates gathering in progress..."));

	ice_session_enable_forced_relay(call->ice_session, lc->forced_ice_relay);
	ice_session_enable_short_turn_refresh(call->ice_session, lc->short_turn_refresh);

	// TODO: Handle IPv6
	/* Gather local host candidates. */
	if (linphone_core_get_local_ip_for(AF_INET, NULL, local_addr) < 0) {
		ms_error("Fail to get local ip");
		return -1;
	}
	if ((ice_check_list_state(audio_check_list) != ICL_Completed) && (ice_check_list_candidates_gathered(audio_check_list) == FALSE)) {
		ice_add_local_candidate(audio_check_list, "host", AF_INET, local_addr, call->media_ports[call->main_audio_stream_index].rtp_port, 1, NULL);
		ice_add_local_candidate(audio_check_list, "host", AF_INET, local_addr, call->media_ports[call->main_audio_stream_index].rtcp_port, 2, NULL);
		call->stats[LINPHONE_CALL_STATS_AUDIO].ice_state = LinphoneIceStateInProgress;
	}
	if (linphone_core_video_enabled(lc) && (video_check_list != NULL)
		&& (ice_check_list_state(video_check_list) != ICL_Completed) && (ice_check_list_candidates_gathered(video_check_list) == FALSE)) {
		ice_add_local_candidate(video_check_list, "host", AF_INET, local_addr, call->media_ports[call->main_video_stream_index].rtp_port, 1, NULL);
		ice_add_local_candidate(video_check_list, "host", AF_INET, local_addr, call->media_ports[call->main_video_stream_index].rtcp_port, 2, NULL);
		call->stats[LINPHONE_CALL_STATS_VIDEO].ice_state = LinphoneIceStateInProgress;
	}
	if (call->params->realtimetext_enabled && (text_check_list != NULL)
		&& (ice_check_list_state(text_check_list) != ICL_Completed) && (ice_check_list_candidates_gathered(text_check_list) == FALSE)) {
		ice_add_local_candidate(text_check_list, "host", AF_INET, local_addr, call->media_ports[call->main_text_stream_index].rtp_port, 1, NULL);
		ice_add_local_candidate(text_check_list, "host", AF_INET, local_addr, call->media_ports[call->main_text_stream_index].rtcp_port, 2, NULL);
		call->stats[LINPHONE_CALL_STATS_TEXT].ice_state = LinphoneIceStateInProgress;
	}
	if ((ai != NULL) && (nat_policy != NULL)
		&& (linphone_nat_policy_stun_enabled(nat_policy) || linphone_nat_policy_turn_enabled(nat_policy))) {
		bool_t gathering_in_progress;
		ms_message("ICE: gathering candidate from [%s] using %s", server, linphone_nat_policy_turn_enabled(nat_policy) ? "TURN" : "STUN");
		/* Gather local srflx candidates. */
		ice_session_enable_turn(call->ice_session, linphone_nat_policy_turn_enabled(nat_policy));
		ice_session_set_stun_auth_requested_cb(call->ice_session, (MSStunAuthRequestedCb)stun_auth_requested_cb, call);
		gathering_in_progress = ice_session_gather_candidates(call->ice_session, ai->ai_addr, (socklen_t)ai->ai_addrlen);
		return (gathering_in_progress == FALSE) ? 0 : 1;
	} else {
		ms_message("ICE: bypass candidates gathering");
		ice_session_compute_candidates_foundations(call->ice_session);
		ice_session_eliminate_redundant_candidates(call->ice_session);
		ice_session_choose_default_candidates(call->ice_session);
	}
	return 0;
}

const char *linphone_ice_state_to_string(LinphoneIceState state){
	switch(state){
		case LinphoneIceStateFailed:
			return "IceStateFailed";
		case LinphoneIceStateHostConnection:
			return "IceStateHostConnection";
		case LinphoneIceStateInProgress:
			return "IceStateInProgress";
		case LinphoneIceStateNotActivated:
			return "IceStateNotActivated";
		case LinphoneIceStateReflexiveConnection:
			return "IceStateReflexiveConnection";
		case LinphoneIceStateRelayConnection:
			return "IceStateRelayConnection";
	}
	return "invalid";
}

void linphone_core_update_ice_state_in_call_stats(LinphoneCall *call)
{
	IceCheckList *audio_check_list;
	IceCheckList *video_check_list;
	IceCheckList *text_check_list;
	IceSessionState session_state;

	if (call->ice_session == NULL) return;
	audio_check_list = ice_session_check_list(call->ice_session, call->main_audio_stream_index);
	video_check_list = ice_session_check_list(call->ice_session, call->main_video_stream_index);
	text_check_list = ice_session_check_list(call->ice_session, call->main_text_stream_index);
	if (audio_check_list == NULL) return;

	session_state = ice_session_state(call->ice_session);
	if ((session_state == IS_Completed) || ((session_state == IS_Failed) && (ice_session_has_completed_check_list(call->ice_session) == TRUE))) {
		if (call->params->has_audio && (audio_check_list != NULL)) {
			if (ice_check_list_state(audio_check_list) == ICL_Completed) {
				switch (ice_check_list_selected_valid_candidate_type(audio_check_list)) {
					case ICT_HostCandidate:
						call->stats[LINPHONE_CALL_STATS_AUDIO].ice_state = LinphoneIceStateHostConnection;
						break;
					case ICT_ServerReflexiveCandidate:
					case ICT_PeerReflexiveCandidate:
						call->stats[LINPHONE_CALL_STATS_AUDIO].ice_state = LinphoneIceStateReflexiveConnection;
						break;
					case ICT_RelayedCandidate:
						call->stats[LINPHONE_CALL_STATS_AUDIO].ice_state = LinphoneIceStateRelayConnection;
						break;
					case ICT_CandidateInvalid:
					case ICT_CandidateTypeMax:
						/*shall not happen*/
						break;
				}
			} else {
				call->stats[LINPHONE_CALL_STATS_AUDIO].ice_state = LinphoneIceStateFailed;
			}
		}else call->stats[LINPHONE_CALL_STATS_AUDIO].ice_state = LinphoneIceStateNotActivated;
		
		if (call->params->has_video && (video_check_list != NULL)) {
			if (ice_check_list_state(video_check_list) == ICL_Completed) {
				switch (ice_check_list_selected_valid_candidate_type(video_check_list)) {
					case ICT_HostCandidate:
						call->stats[LINPHONE_CALL_STATS_VIDEO].ice_state = LinphoneIceStateHostConnection;
						break;
					case ICT_ServerReflexiveCandidate:
					case ICT_PeerReflexiveCandidate:
						call->stats[LINPHONE_CALL_STATS_VIDEO].ice_state = LinphoneIceStateReflexiveConnection;
						break;
					case ICT_RelayedCandidate:
						call->stats[LINPHONE_CALL_STATS_VIDEO].ice_state = LinphoneIceStateRelayConnection;
						break;
					case ICT_CandidateInvalid:
					case ICT_CandidateTypeMax:
						/*shall not happen*/
						break;
				}
			} else {
				call->stats[LINPHONE_CALL_STATS_VIDEO].ice_state = LinphoneIceStateFailed;
			}
		}else call->stats[LINPHONE_CALL_STATS_VIDEO].ice_state = LinphoneIceStateNotActivated;
		
		if (call->params->realtimetext_enabled && (text_check_list != NULL)) {
			if (ice_check_list_state(text_check_list) == ICL_Completed) {
				switch (ice_check_list_selected_valid_candidate_type(text_check_list)) {
					case ICT_HostCandidate:
						call->stats[LINPHONE_CALL_STATS_TEXT].ice_state = LinphoneIceStateHostConnection;
						break;
					case ICT_ServerReflexiveCandidate:
					case ICT_PeerReflexiveCandidate:
						call->stats[LINPHONE_CALL_STATS_TEXT].ice_state = LinphoneIceStateReflexiveConnection;
						break;
					case ICT_RelayedCandidate:
						call->stats[LINPHONE_CALL_STATS_TEXT].ice_state = LinphoneIceStateRelayConnection;
						break;
					case ICT_CandidateInvalid:
					case ICT_CandidateTypeMax:
						/*shall not happen*/
						break;
				}
			} else {
				call->stats[LINPHONE_CALL_STATS_TEXT].ice_state = LinphoneIceStateFailed;
			}
		}else call->stats[LINPHONE_CALL_STATS_TEXT].ice_state = LinphoneIceStateNotActivated;
	} else if (session_state == IS_Running) {
		call->stats[LINPHONE_CALL_STATS_AUDIO].ice_state = LinphoneIceStateInProgress;
		if (call->params->has_video && (video_check_list != NULL)) {
			call->stats[LINPHONE_CALL_STATS_VIDEO].ice_state = LinphoneIceStateInProgress;
		}
		if (call->params->realtimetext_enabled && (text_check_list != NULL)) {
			call->stats[LINPHONE_CALL_STATS_TEXT].ice_state = LinphoneIceStateInProgress;
		}
	} else {
		call->stats[LINPHONE_CALL_STATS_AUDIO].ice_state = LinphoneIceStateFailed;
		if (call->params->has_video && (video_check_list != NULL)) {