freeswitch/src/switch_rtp.c

/* 
 * FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application
 * Copyright (C) 2005/2006, Anthony Minessale II <anthmct@yahoo.com>
 *
 * Version: MPL 1.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application
 *
 * The Initial Developer of the Original Code is
 * Anthony Minessale II <anthmct@yahoo.com>
 * Portions created by the Initial Developer are Copyright (C)
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 * 
 * Anthony Minessale II <anthmct@yahoo.com>
 *
 *
 * switch_rtp.c -- RTP
 *
 */

#ifdef HAVE_SYS_SOCKET_H
# include <sys/socket.h>
#endif
#ifdef HAVE_NETINET_IN_H
# include <netinet/in.h>
#elif defined HAVE_WINSOCK2_H
# include <winsock2.h>
# include <ws2tcpip.h>
# define RTPW_USE_WINSOCK2	1
#endif
#ifdef HAVE_ARPA_INET_H
# include <arpa/inet.h>
#endif



#ifdef RTPW_USE_WINSOCK2
# define DICT_FILE        "words.txt"
#else
# define DICT_FILE        "/usr/share/dict/words"
#endif
#define USEC_RATE        (5e5)
#define MAX_WORD_LEN     128  
#define ADDR_IS_MULTICAST(a) IN_MULTICAST(htonl(a))
#define MAX_KEY_LEN      64
#define MASTER_KEY_LEN   30

#include <switch.h>
#undef PACKAGE_NAME
#undef PACKAGE_STRING
#undef PACKAGE_TARNAME
#undef PACKAGE_VERSION
#undef PACKAGE_BUGREPORT
#include <datatypes.h>
#include <srtp.h>

#include <fcntl.h>
#include <netinet/in.h>
#include <arpa/inet.h>


#define do_close(s) if (s > -1) {close(s); s = -1;}

#define rtp_header_len 12

typedef srtp_hdr_t rtp_hdr_t;

#define RTP_MAX_BUF_LEN 16384

typedef struct {
  srtp_hdr_t header;        
  char body[RTP_MAX_BUF_LEN];  
} rtp_msg_t;


struct switch_rtp {
	switch_raw_socket_t sock;

	struct sockaddr_in local_addr;
	rtp_msg_t send_msg;
	srtp_ctx_t *send_ctx;

	struct sockaddr_in remote_addr;
	rtp_msg_t recv_msg;
	srtp_ctx_t *recv_ctx;
	
	uint32_t seq;
	uint32_t payload;
	
	switch_rtp_invalid_handler invalid_handler;
	void *private_data;

	uint32_t ts;
	uint32_t flags;
};

static int global_init = 0;

static void init_rtp(void)
{
	if (global_init) {
		return;
	}

#ifdef RTPW_USE_WINSOCK2
  WORD wVersionRequested = MAKEWORD(2, 0);
  WSADATA wsaData;

  ret = WSAStartup(wVersionRequested, &wsaData);
#endif

  srtp_init();
  global_init = 1;

}

switch_rtp *switch_rtp_new(char *rx_ip,
						   int rx_port,
						   char *tx_ip,
						   int tx_port,
						   int payload,
						   switch_rtp_flag_t flags,
						   const char **err,
						   switch_memory_pool *pool)
{
	switch_raw_socket_t sock;
	switch_rtp *rtp_session = NULL;
	struct in_addr rx_addr, tx_addr;
	srtp_policy_t policy;
	char key[MAX_KEY_LEN];
	uint32_t ssrc = rand() & 0xffff;

	if (!global_init) {
		init_rtp();
	}

	if ((sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {
		*err = "Socket Error!\n";
		return NULL;
	}

	if (!inet_aton(rx_ip, &rx_addr)) {
		*err = "RX Address Error!\n";
		return NULL;
	}	

	if (!inet_aton(tx_ip, &tx_addr)) {
		*err = "TX Address Error!\n";
		return NULL;
	}	

	if (!(rtp_session = switch_core_alloc(pool, sizeof(*rtp_session)))) {
		*err = "Memory Error!";
		return NULL;
	}

	rtp_session->flags = flags;
	rtp_session->local_addr.sin_addr = rx_addr;
	rtp_session->local_addr.sin_family = PF_INET;
	rtp_session->local_addr.sin_port   = htons(rx_port);

	rtp_session->remote_addr.sin_addr = tx_addr;
	rtp_session->remote_addr.sin_family = PF_INET;
	rtp_session->remote_addr.sin_port   = htons(tx_port);
	rtp_session->sock = sock;

	
	if (bind(sock, (struct sockaddr *)&rtp_session->local_addr, sizeof(rtp_session->local_addr)) < 0) {
		*err = "Bind Err!";
		close(sock);
		return NULL;
	}

	if switch_test_flag(rtp_session, SWITCH_RTP_NOBLOCK) {
		fcntl(sock, F_SETFL, O_NONBLOCK);
	}

    policy.key                 = (uint8_t *)key;
    policy.ssrc.type           = ssrc_specific;
    policy.ssrc.value          = ssrc;
    policy.rtp.cipher_type     = NULL_CIPHER;
    policy.rtp.cipher_key_len  = 0; 
    policy.rtp.auth_type       = NULL_AUTH;
    policy.rtp.auth_key_len    = 0;
    policy.rtp.auth_tag_len    = 0;
    policy.rtp.sec_serv        = sec_serv_none;   
    policy.rtcp.cipher_type    = NULL_CIPHER;
    policy.rtcp.cipher_key_len = 0; 
    policy.rtcp.auth_type      = NULL_AUTH;
    policy.rtcp.auth_key_len   = 0;
    policy.rtcp.auth_tag_len   = 0;
    policy.rtcp.sec_serv       = sec_serv_none;   
    policy.next                = NULL;


	rtp_session->send_msg.header.ssrc    = htonl(ssrc);
	rtp_session->send_msg.header.ts      = 0;
	rtp_session->send_msg.header.seq     = (uint16_t) rand();
	rtp_session->send_msg.header.m       = 0;
	rtp_session->send_msg.header.pt      = htonl(payload);
	rtp_session->send_msg.header.version = 2;
	rtp_session->send_msg.header.p       = 0;
	rtp_session->send_msg.header.x       = 0;
	rtp_session->send_msg.header.cc      = 0;


	rtp_session->recv_msg.header.ssrc    = htonl(ssrc);
	rtp_session->recv_msg.header.ts      = 0;
	rtp_session->recv_msg.header.seq     = 0;
	rtp_session->recv_msg.header.m       = 0;
	rtp_session->recv_msg.header.pt      = htonl(payload);
	rtp_session->recv_msg.header.version = 2;
	rtp_session->recv_msg.header.p       = 0;
	rtp_session->recv_msg.header.x       = 0;
	rtp_session->recv_msg.header.cc      = 0;

	rtp_session->seq = rtp_session->send_msg.header.seq;
	rtp_session->payload = payload;
	srtp_create(&rtp_session->recv_ctx, &policy);
	srtp_create(&rtp_session->send_ctx, &policy);

	return rtp_session;
}

void switch_rtp_killread(switch_rtp *rtp_session)
{
	switch_clear_flag(rtp_session, SWITCH_RTP_FLAG_IO);
	shutdown(rtp_session->sock, SHUT_RDWR);
}


void switch_rtp_destroy(switch_rtp **rtp_session)
{

	switch_rtp_killread(*rtp_session);
	do_close((*rtp_session)->sock);
	*rtp_session = NULL;
	return;
}

switch_raw_socket_t switch_rtp_get_rtp_socket(switch_rtp *rtp_session)
{
	return rtp_session->sock;
}

void switch_rtp_set_invald_handler(switch_rtp *rtp_session, switch_rtp_invalid_handler on_invalid)
{
	rtp_session->invalid_handler = on_invalid;
}

int switch_rtp_read(switch_rtp *rtp_session, void *data, uint32_t datalen, int *payload_type)
{
	int32_t bytes;
	struct sockaddr_in in;
	unsigned int len = sizeof(struct sockaddr_in);

	if (!switch_test_flag(rtp_session, SWITCH_RTP_FLAG_IO)) {
		return -1;
	}

	bytes = recvfrom(rtp_session->sock, (void *)&rtp_session->recv_msg, sizeof(rtp_msg_t), 0, (struct sockaddr *) &in, &len);
	if (bytes <= 0) {
		return 0;
	}
	
	if (rtp_session->recv_msg.header.version != 2) {
		if (rtp_session->invalid_handler) {
			rtp_session->invalid_handler(rtp_session, rtp_session->sock, (void *) &rtp_session->recv_msg, bytes, in.sin_addr.s_addr, in.sin_port);
		}
		return 0;
	}
	memcpy(data, rtp_session->recv_msg.body, bytes);
	*payload_type = rtp_session->recv_msg.header.pt;
	return bytes - rtp_header_len;

}


int switch_rtp_zerocopy_read(switch_rtp *rtp_session, void **data, int *payload_type)
{
	int32_t bytes;
	struct sockaddr_in in;
	unsigned int len = sizeof(struct sockaddr_in);

	*data = NULL;
	if (!switch_test_flag(rtp_session, SWITCH_RTP_FLAG_IO)) {
		return -1;
	}

	bytes = recvfrom(rtp_session->sock, (void *)&rtp_session->recv_msg, sizeof(rtp_msg_t), 0, (struct sockaddr *) &in, &len);
	if (bytes <= 0) {
		return 0;
	}
	
	if (rtp_session->recv_msg.header.version != 2) {
		if (rtp_session->invalid_handler) {
			rtp_session->invalid_handler(rtp_session, rtp_session->sock, (void *) &rtp_session->recv_msg, bytes, in.sin_addr.s_addr, ntohs(in.sin_port));
		}
		return 0;
	}
	*payload_type = rtp_session->recv_msg.header.pt;
	*data = rtp_session->recv_msg.body;

	return bytes - rtp_header_len;
}

int switch_rtp_write(switch_rtp *rtp_session, void *data, int datalen, uint32_t ts)
{
	int32_t bytes;

	if (!switch_test_flag(rtp_session, SWITCH_RTP_FLAG_IO)) {
		return -1;
	}
	rtp_session->ts += ts;
	rtp_session->seq = ntohs(rtp_session->seq) + 1;
	rtp_session->seq = htons(rtp_session->seq);
	rtp_session->send_msg.header.seq = rtp_session->seq;
	rtp_session->send_msg.header.ts = htonl(rtp_session->ts);
	rtp_session->payload = htonl(rtp_session->payload);

	memcpy(rtp_session->send_msg.body, data, datalen);
	bytes = sendto(rtp_session->sock, (void*)&rtp_session->send_msg,
				   datalen + rtp_header_len, 0, (struct sockaddr *)&rtp_session->remote_addr, sizeof (struct sockaddr_in));

	return bytes;
}

int switch_rtp_write_payload(switch_rtp *rtp_session, void *data, int datalen, int payload, uint32_t ts, uint32_t mseq)
{
	int32_t bytes;

	if (!switch_test_flag(rtp_session, SWITCH_RTP_FLAG_IO)) {
		return -1;
	}
	rtp_session->ts += ts;
	rtp_session->send_msg.header.seq = htons(mseq);
	rtp_session->send_msg.header.ts = htonl(rtp_session->ts);
	rtp_session->send_msg.header.pt = htonl(payload);

	memcpy(rtp_session->send_msg.body, data, datalen);
	bytes = sendto(rtp_session->sock, (void*)&rtp_session->send_msg,
				   datalen + rtp_header_len, 0, (struct sockaddr *)&rtp_session->remote_addr, sizeof (struct sockaddr_in));
	
	return bytes;
}

uint32_t switch_rtp_start(switch_rtp *rtp_session)
{
	switch_set_flag(rtp_session, SWITCH_RTP_FLAG_IO);
	return 0;
}

uint32_t switch_rtp_get_ssrc(switch_rtp *rtp_session)
{
	return rtp_session->send_msg.header.ssrc;
}

void switch_rtp_set_private(switch_rtp *rtp_session, void *private_data)
{
	rtp_session->private_data = private_data;
}

void *switch_rtp_get_private(switch_rtp *rtp_session)
{
	return rtp_session->private_data;
}