📄 groupsockhelper.cpp
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/**********This library is free software; you can redistribute it and/or modify it underthe terms of the GNU Lesser General Public License as published by theFree Software Foundation; either version 2.1 of the License, or (at youroption) any later version. (See <http://www.gnu.org/copyleft/lesser.html>.)This library is distributed in the hope that it will be useful, but WITHOUTANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESSFOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License formore details.You should have received a copy of the GNU Lesser General Public Licensealong with this library; if not, write to the Free Software Foundation, Inc.,51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA**********/// "mTunnel" multicast access service// Copyright (c) 1996-2010 Live Networks, Inc. All rights reserved.// Helper routines to implement 'group sockets'// Implementation#include "GroupsockHelper.hh"#if defined(__WIN32__) || defined(_WIN32)#include <time.h>extern "C" int initializeWinsockIfNecessary();#else#include <stdarg.h>#include <time.h>#include <fcntl.h>#define initializeWinsockIfNecessary() 1#endif#include <stdio.h>// By default, use INADDR_ANY for the sending and receiving interfaces:netAddressBits SendingInterfaceAddr = INADDR_ANY;netAddressBits ReceivingInterfaceAddr = INADDR_ANY;static void socketErr(UsageEnvironment& env, char const* errorMsg) { env.setResultErrMsg(errorMsg);}static int reuseFlag = 1;NoReuse::NoReuse() { reuseFlag = 0;}NoReuse::~NoReuse() { reuseFlag = 1;}int setupDatagramSocket(UsageEnvironment& env, Port port) { if (!initializeWinsockIfNecessary()) { socketErr(env, "Failed to initialize 'winsock': "); return -1; } int newSocket = socket(AF_INET, SOCK_DGRAM, 0); if (newSocket < 0) { socketErr(env, "unable to create datagram socket: "); return newSocket; } if (setsockopt(newSocket, SOL_SOCKET, SO_REUSEADDR, (const char*)&reuseFlag, sizeof reuseFlag) < 0) { socketErr(env, "setsockopt(SO_REUSEADDR) error: "); closeSocket(newSocket); return -1; }#if defined(__WIN32__) || defined(_WIN32) // Windoze doesn't properly handle SO_REUSEPORT or IP_MULTICAST_LOOP#else#ifdef SO_REUSEPORT if (setsockopt(newSocket, SOL_SOCKET, SO_REUSEPORT, (const char*)&reuseFlag, sizeof reuseFlag) < 0) { socketErr(env, "setsockopt(SO_REUSEPORT) error: "); closeSocket(newSocket); return -1; }#endif#ifdef IP_MULTICAST_LOOP const u_int8_t loop = 1; if (setsockopt(newSocket, IPPROTO_IP, IP_MULTICAST_LOOP, (const char*)&loop, sizeof loop) < 0) { socketErr(env, "setsockopt(IP_MULTICAST_LOOP) error: "); closeSocket(newSocket); return -1; }#endif#endif // Note: Windoze requires binding, even if the port number is 0 netAddressBits addr = INADDR_ANY;#if defined(__WIN32__) || defined(_WIN32)#else if (port.num() != 0 || ReceivingInterfaceAddr != INADDR_ANY) {#endif if (port.num() == 0) addr = ReceivingInterfaceAddr; MAKE_SOCKADDR_IN(name, addr, port.num()); if (bind(newSocket, (struct sockaddr*)&name, sizeof name) != 0) { char tmpBuffer[100]; sprintf(tmpBuffer, "bind() error (port number: %d): ", ntohs(port.num())); socketErr(env, tmpBuffer); closeSocket(newSocket); return -1; }#if defined(__WIN32__) || defined(_WIN32)#else }#endif // Set the sending interface for multicasts, if it's not the default: if (SendingInterfaceAddr != INADDR_ANY) { struct in_addr addr; addr.s_addr = SendingInterfaceAddr; if (setsockopt(newSocket, IPPROTO_IP, IP_MULTICAST_IF, (const char*)&addr, sizeof addr) < 0) { socketErr(env, "error setting outgoing multicast interface: "); closeSocket(newSocket); return -1; } } return newSocket;}Boolean makeSocketNonBlocking(int sock) {#if defined(__WIN32__) || defined(_WIN32) || defined(IMN_PIM) unsigned long arg = 1; return ioctlsocket(sock, FIONBIO, &arg) == 0;#elif defined(VXWORKS) int arg = 1; return ioctl(sock, FIONBIO, (int)&arg) == 0;#else int curFlags = fcntl(sock, F_GETFL, 0); return fcntl(sock, F_SETFL, curFlags|O_NONBLOCK) >= 0;#endif}Boolean makeSocketBlocking(int sock) {
#if defined(__WIN32__) || defined(_WIN32) || defined(IMN_PIM)
unsigned long arg = 0;
return ioctlsocket(sock, FIONBIO, &arg) == 0;
#elif defined(VXWORKS)
int arg = 0;
return ioctl(sock, FIONBIO, (int)&arg) == 0;
#else
int curFlags = fcntl(sock, F_GETFL, 0);
return fcntl(sock, F_SETFL, curFlags&(~O_NONBLOCK)) >= 0;
#endif
}int setupStreamSocket(UsageEnvironment& env, Port port, Boolean makeNonBlocking) { if (!initializeWinsockIfNecessary()) { socketErr(env, "Failed to initialize 'winsock': "); return -1; } int newSocket = socket(AF_INET, SOCK_STREAM, 0); if (newSocket < 0) { socketErr(env, "unable to create stream socket: "); return newSocket; } if (setsockopt(newSocket, SOL_SOCKET, SO_REUSEADDR, (const char*)&reuseFlag, sizeof reuseFlag) < 0) { socketErr(env, "setsockopt(SO_REUSEADDR) error: "); closeSocket(newSocket); return -1; } // SO_REUSEPORT doesn't really make sense for TCP sockets, so we // normally don't set them. However, if you really want to do this // #define REUSE_FOR_TCP#ifdef REUSE_FOR_TCP#if defined(__WIN32__) || defined(_WIN32) // Windoze doesn't properly handle SO_REUSEPORT#else#ifdef SO_REUSEPORT if (setsockopt(newSocket, SOL_SOCKET, SO_REUSEPORT, (const char*)&reuseFlag, sizeof reuseFlag) < 0) { socketErr(env, "setsockopt(SO_REUSEPORT) error: "); closeSocket(newSocket); return -1; }#endif#endif#endif // Note: Windoze requires binding, even if the port number is 0#if defined(__WIN32__) || defined(_WIN32)#else if (port.num() != 0 || ReceivingInterfaceAddr != INADDR_ANY) {#endif MAKE_SOCKADDR_IN(name, ReceivingInterfaceAddr, port.num()); if (bind(newSocket, (struct sockaddr*)&name, sizeof name) != 0) { char tmpBuffer[100]; sprintf(tmpBuffer, "bind() error (port number: %d): ", ntohs(port.num())); socketErr(env, tmpBuffer); closeSocket(newSocket); return -1; }#if defined(__WIN32__) || defined(_WIN32)#else }#endif if (makeNonBlocking) { if (!makeSocketNonBlocking(newSocket)) { socketErr(env, "failed to make non-blocking: "); closeSocket(newSocket); return -1; } } return newSocket;}int readSocket(UsageEnvironment& env, int socket, unsigned char* buffer, unsigned bufferSize, struct sockaddr_in& fromAddress) { SOCKLEN_T addressSize = sizeof fromAddress; int bytesRead = recvfrom(socket, (char*)buffer, bufferSize, 0, (struct sockaddr*)&fromAddress, &addressSize); if (bytesRead < 0) { //##### HACK to work around bugs in Linux and Windows: int err = env.getErrno(); if (err == 111 /*ECONNREFUSED (Linux)*/#if defined(__WIN32__) || defined(_WIN32) // What a piece of crap Windows is. Sometimes // recvfrom() returns -1, but with an 'errno' of 0. // This appears not to be a real error; just treat // it as if it were a read of zero bytes, and hope // we don't have to do anything else to 'reset' // this alleged error: || err == 0 || err == EWOULDBLOCK#else || err == EAGAIN#endif || err == 113 /*EHOSTUNREACH (Linux)*/) { // Why does Linux return this for datagram sock? fromAddress.sin_addr.s_addr = 0; return 0; } //##### END HACK socketErr(env, "recvfrom() error: "); } return bytesRead;}Boolean writeSocket(UsageEnvironment& env, int socket, struct in_addr address, Port port, u_int8_t ttlArg, unsigned char* buffer, unsigned bufferSize) { do { if (ttlArg != 0) { // Before sending, set the socket's TTL:#if defined(__WIN32__) || defined(_WIN32)#define TTL_TYPE int#else#define TTL_TYPE u_int8_t#endif TTL_TYPE ttl = (TTL_TYPE)ttlArg; if (setsockopt(socket, IPPROTO_IP, IP_MULTICAST_TTL, (const char*)&ttl, sizeof ttl) < 0) { socketErr(env, "setsockopt(IP_MULTICAST_TTL) error: "); break; } } MAKE_SOCKADDR_IN(dest, address.s_addr, port.num()); int bytesSent = sendto(socket, (char*)buffer, bufferSize, 0, (struct sockaddr*)&dest, sizeof dest); if (bytesSent != (int)bufferSize) { char tmpBuf[100]; sprintf(tmpBuf, "writeSocket(%d), sendTo() error: wrote %d bytes instead of %u: ", socket, bytesSent, bufferSize); socketErr(env, tmpBuf); break; } return True; } while (0); return False;}static unsigned getBufferSize(UsageEnvironment& env, int bufOptName, int socket) { unsigned curSize; SOCKLEN_T sizeSize = sizeof curSize; if (getsockopt(socket, SOL_SOCKET, bufOptName, (char*)&curSize, &sizeSize) < 0) { socketErr(env, "getBufferSize() error: "); return 0; } return curSize;}unsigned getSendBufferSize(UsageEnvironment& env, int socket) { return getBufferSize(env, SO_SNDBUF, socket);}unsigned getReceiveBufferSize(UsageEnvironment& env, int socket) { return getBufferSize(env, SO_RCVBUF, socket);}static unsigned setBufferTo(UsageEnvironment& env, int bufOptName, int socket, unsigned requestedSize) { SOCKLEN_T sizeSize = sizeof requestedSize; setsockopt(socket, SOL_SOCKET, bufOptName, (char*)&requestedSize, sizeSize); // Get and return the actual, resulting buffer size: return getBufferSize(env, bufOptName, socket);}unsigned setSendBufferTo(UsageEnvironment& env, int socket, unsigned requestedSize) { return setBufferTo(env, SO_SNDBUF, socket, requestedSize);}unsigned setReceiveBufferTo(UsageEnvironment& env, int socket, unsigned requestedSize) { return setBufferTo(env, SO_RCVBUF, socket, requestedSize);}static unsigned increaseBufferTo(UsageEnvironment& env, int bufOptName, int socket, unsigned requestedSize) { // First, get the current buffer size. If it's already at least // as big as what we're requesting, do nothing. unsigned curSize = getBufferSize(env, bufOptName, socket); // Next, try to increase the buffer to the requested size, // or to some smaller size, if that's not possible: while (requestedSize > curSize) { SOCKLEN_T sizeSize = sizeof requestedSize; if (setsockopt(socket, SOL_SOCKET, bufOptName, (char*)&requestedSize, sizeSize) >= 0) { // success return requestedSize; } requestedSize = (requestedSize+curSize)/2; } return getBufferSize(env, bufOptName, socket);}unsigned increaseSendBufferTo(UsageEnvironment& env, int socket, unsigned requestedSize) { return increaseBufferTo(env, SO_SNDBUF, socket, requestedSize);}unsigned increaseReceiveBufferTo(UsageEnvironment& env, int socket, unsigned requestedSize) {
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