alc_socket.c

这个程序实现了FLUTE协议

/* $Author: peltotal $ $Date: 2006/02/17 09:14:36 $ $Revision: 1.30 $ */
/*
 *   MAD-ALCLIB: Implementation of ALC/LCT protocols, Compact No-Code FEC,
 *   Simple XOR FEC, Reed-Solomon FEC, and RLC Congestion Control protocol.
 *   Copyright (c) 2003-2006 TUT - Tampere University of Technology
 *   main authors/contacts: [e-mail] and [e-mail]
 *
 *   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 "inc.h"

/*
 * This function creates and initializes tx or rx socket
 *
 * Params:	alc_channel_t *ch: Pointer to channel 
 *
 * Return:	int: 0 in success, -1 otherwise
 *
 */

int init_alc_socket(alc_channel_t *ch) {
	
	int receiver_socket_buffer_size = RECEIVER_SOCKET_BUFFER_SIZE;
	int ttl;
	int loop;
	int reuse;
	int mode;
	int addr_type;
	struct addrinfo hints, *local;
	struct in_addr if_addr;	/* interface IP address for IPv4 multicast */
  
#if defined(LINUX) && defined(SSM)
	struct sockaddr_in6 source;
#endif
  
	local = NULL;
	mode = ch->s->mode;
	addr_type = ch->s->addr_type;
  
	if(mode == SENDER) {
    
		if((ch->tx_sock  = socket(ch->s->addr_family, SOCK_DGRAM, 0)) < 0) {
      
#ifdef WIN32
			printf("socket failed with: %d\n", WSAGetLastError());
			fflush(stdout);
#else
			printf("socket failed: %d\n", errno);
			fflush(stdout);
#endif
			return -1;
		}
    
		memset(&hints, 0, sizeof(hints));
		hints.ai_family = ch->s->addr_family;
		hints.ai_socktype = SOCK_DGRAM;
    
		/* ch->addrinfo is used in sendto function */
    
		if(getaddrinfo(ch->addr, ch->port, &hints, &ch->addrinfo) != 0) {
#ifdef WIN32
			printf("getaddrinfo failed: %d\n", WSAGetLastError());
			fflush(stdout);
			closesocket(ch->tx_sock);
#else
			printf("getaddrinfo failed: %d\n", errno);
			fflush(stdout);	
			close(ch->tx_sock);
#endif
			return -1;
		}
    
		/* Bind the socket to right interface */
    
		if(ch->intface != NULL) {
      
			if((((ch->s->addr_family == PF_INET6)) || (addr_type == 1))) {
	
				if(getaddrinfo(ch->intface, 0, &hints, &local) != 0) {
#ifdef WIN32
					printf("getaddrinfo failed: %d\n", WSAGetLastError());
					closesocket(ch->tx_sock);
#else
					printf("getaddrinfo failed: %d\n", errno);
					close(ch->tx_sock);
#endif
					return -1;
				}
	
				if(bind(ch->tx_sock, local->ai_addr, local->ai_addrlen) < 0) {
#ifdef WIN32
					printf("bind failed: %d\n", WSAGetLastError());
					closesocket(ch->tx_sock);
#else
					printf("bind failed: %d\n", errno);
					close(ch->tx_sock);
#endif
					return -1;
				}
			}
			else if(((ch->s->addr_family == PF_INET) && (addr_type == 0))) {
				/* does not work without this interface setting */
				if_addr.s_addr = inet_addr(ch->intface);
				
				/* specify multicast interface */
				if(setsockopt(ch->tx_sock, IPPROTO_IP, IP_MULTICAST_IF, 
						  (char*)&if_addr.s_addr, sizeof(if_addr.s_addr)) < 0 ) {
	  
#ifdef WIN32
					printf("setsockopt (IP_MULTICAST_IF) failed: %d\n", WSAGetLastError());
					closesocket(ch->tx_sock);
#else
					printf("setsockopt (IP_MULTICAST_IF) failed: %d\n", errno);
					close(ch->tx_sock);
#endif
					return -1;
				}
			}
		}
    
		if(addr_type == 0) {
      
			/* TTL */
			ttl = min(ch->s->def_ttl, 255);
      
			if(ch->s->addr_family == PF_INET) {
	
				if(setsockopt(ch->tx_sock, IPPROTO_IP, IP_MULTICAST_TTL, 
					(char *)&ttl, sizeof(ttl)) < 0 ) {
#ifdef WIN32
					printf("setsockopt (IP_MULTICAST_TTL) failed: %d\n", WSAGetLastError());
					closesocket(ch->tx_sock);
#else
					printf("setsockopt (IP_MULTICAST_TTL) failed: %d\n", errno);
					close(ch->tx_sock);
#endif /* WIN32 */
	  
					return -1;
				}
			}
			else if(ch->s->addr_family == PF_INET6) {
	
				if(setsockopt(ch->tx_sock, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, 
					(char *)&ttl, sizeof(ttl)) < 0 ) {
#ifdef WIN32
					printf("setsockopt (IPV6_MULTICAST_HOPS) failed: %d\n", WSAGetLastError());
					closesocket(ch->tx_sock);
#else
					printf("setsockopt (IPV6_MULTICAST_HOPS) failed: %d\n", errno);
					close(ch->tx_sock);
#endif /* WIN32 */
					return -1;
				}
			}	
      
			/* Loopback (doesn't work in Windows, even if loop = 0, data is looped back) */
			/* set to 0, when you don't have to do testing any more */
			loop = 1;
      
			if(ch->s->addr_family == PF_INET) {
	
				if(setsockopt(ch->tx_sock, IPPROTO_IP, IP_MULTICAST_LOOP, 
					(char *)&loop, sizeof(loop)) != 0) {
#ifdef WIN32
					printf("setsockopt (IP_MULTICAST_LOOP) failed: %d\n", WSAGetLastError());
					closesocket(ch->tx_sock);
#else
					printf("setsockopt (IP_MULTICAST_LOOP) failed: %d\n", errno);
					close(ch->tx_sock);
#endif /* WIN32 */
					return -1;
				}
			}
			else if(ch->s->addr_family == PF_INET6) {
	
				if(setsockopt(ch->tx_sock, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, 
					(char *)&loop, sizeof(loop)) != 0) {
#ifdef WIN32
					printf("setsockopt (IPV6_MULTICAST_LOOP) failed: %d\n", WSAGetLastError());
					closesocket(ch->tx_sock);
#else
					printf("setsockopt (IPV6_MULTICAST_LOOP) failed: %d\n", errno);
					close(ch->tx_sock);
#endif /* WIN32 */
					return -1;
				}
			}
		}
    
		if(local != NULL) {
			freeaddrinfo(local);
		}
	}
  
	if(mode == RECEIVER) {

		if((ch->rx_sock = socket(ch->s->addr_family, SOCK_DGRAM, 0)) < 0) {
      
#ifdef WIN32
			printf("socket failed with: %d\n", WSAGetLastError());
			fflush(stdout);
#else
			printf("socket failed: %d\n", errno);
			fflush(stdout);
#endif
			return -1;
		}
    
		memset(&hints, 0, sizeof(hints));
		hints.ai_family = ch->s->addr_family;
		hints.ai_socktype = SOCK_DGRAM;
		hints.ai_flags = AI_PASSIVE;
    
		if(getaddrinfo(ch->intface, ch->port, &hints, &ch->addrinfo) != 0) {
#ifdef WIN32
			printf("getaddrinfo failed: %d\n", WSAGetLastError());
			closesocket(ch->tx_sock);
#else
			printf("getaddrinfo failed: %d\n", errno);
			close(ch->tx_sock);
#endif
			return -1;
		}	
    
		reuse = 1;

		if(setsockopt(ch->rx_sock, SOL_SOCKET, SO_REUSEADDR, 
					(char *)&reuse, sizeof(reuse)) < 0 ) {
#ifdef WIN32
			printf("setsockopt (SO_REUSEADDR) failed: %d\n", WSAGetLastError());
			closesocket(ch->rx_sock);
#else
			printf("setsockopt (SO_REUSEADDR) failed: %d\n", errno);
			close(ch->rx_sock);
#endif
			return -1;
		}

		if(setsockopt(ch->rx_sock, SOL_SOCKET, SO_RCVBUF, (char *)&receiver_socket_buffer_size, sizeof(int))) {
#ifdef WIN32
			printf("setsockopt (SO_RCVBUF) failed: %d\n", WSAGetLastError());
			closesocket(ch->rx_sock);
#else
			printf("setsockopt (SO_RCVBUF) failed: %d\n", errno);
			close(ch->rx_sock);
#endif
			return -1;
		}

		if(bind(ch->rx_sock, ch->addrinfo->ai_addr, ch->addrinfo->ai_addrlen) < 0) {

#ifdef WIN32
			printf("bind failed: %d\n", WSAGetLastError());
			closesocket(ch->rx_sock);
#else
			printf("bind failed: %d\n", errno);
			close(ch->rx_sock);
#endif
			return -1;
		}
    
		if(addr_type == 0) {
			if(ch->s->addr_family == PF_INET) {
	
				memset((void *)&ch->remote, 0, sizeof(ch->remote));
	
				ch->remote.sin_addr.s_addr = inet_addr(ch->addr);
				ch->remote.sin_port = (unsigned short)atoi(ch->port);
				ch->remote.sin_family = ch->s->addr_family;
			}
			else if(ch->s->addr_family == PF_INET6) {
	
				memset((void *)&ch->remote6, 0, sizeof(ch->remote6));
#ifdef WIN32
				WSAStringToAddress(ch->addr, PF_INET6, NULL, (struct sockaddr*)&ch->remote6,
					&ch->addrinfo->ai_addrlen);
#else
				inet_pton(PF_INET6, ch->addr, &ch->remote6.sin6_addr);
#endif
				ch->remote6.sin6_port = (unsigned short)atoi(ch->port);
				ch->remote6.sin6_family = ch->s->addr_family;
			}
		}
    
		if(addr_type == 0) {