NXDNClients/NXDNParrot/UDPSocket.cpp

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2018-03-13 18:16:48 -04:00
/*
* Copyright (C) 2006-2016,2018 by Jonathan Naylor G4KLX
*
* 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "UDPSocket.h"
#include <cassert>
#if !defined(_WIN32) && !defined(_WIN64)
#include <cerrno>
#include <cstring>
#endif
CUDPSocket::CUDPSocket(const std::string& address, unsigned int port) :
m_address(address),
m_port(port),
m_fd(-1)
{
assert(!address.empty());
#if defined(_WIN32) || defined(_WIN64)
WSAData data;
int wsaRet = ::WSAStartup(MAKEWORD(2, 2), &data);
if (wsaRet != 0)
::fprintf(stderr, "Error from WSAStartup\n");
#endif
}
CUDPSocket::CUDPSocket(unsigned int port) :
m_address(),
m_port(port),
m_fd(-1)
{
#if defined(_WIN32) || defined(_WIN64)
WSAData data;
int wsaRet = ::WSAStartup(MAKEWORD(2, 2), &data);
if (wsaRet != 0)
::fprintf(stderr, "Error from WSAStartup\n");
#endif
}
CUDPSocket::~CUDPSocket()
{
#if defined(_WIN32) || defined(_WIN64)
::WSACleanup();
#endif
}
in_addr CUDPSocket::lookup(const std::string& hostname)
{
in_addr addr;
#if defined(_WIN32) || defined(_WIN64)
unsigned long address = ::inet_addr(hostname.c_str());
if (address != INADDR_NONE && address != INADDR_ANY) {
addr.s_addr = address;
return addr;
}
struct hostent* hp = ::gethostbyname(hostname.c_str());
if (hp != NULL) {
::memcpy(&addr, hp->h_addr_list[0], sizeof(struct in_addr));
return addr;
}
::fprintf(stderr, "Cannot find address for host %s\n", hostname.c_str());
addr.s_addr = INADDR_NONE;
return addr;
#else
in_addr_t address = ::inet_addr(hostname.c_str());
if (address != in_addr_t(-1)) {
addr.s_addr = address;
return addr;
}
struct hostent* hp = ::gethostbyname(hostname.c_str());
if (hp != NULL) {
::memcpy(&addr, hp->h_addr_list[0], sizeof(struct in_addr));
return addr;
}
::fprintf(stderr, "Cannot find address for host %s\n", hostname.c_str());
addr.s_addr = INADDR_NONE;
return addr;
#endif
}
bool CUDPSocket::open()
{
m_fd = ::socket(PF_INET, SOCK_DGRAM, 0);
if (m_fd < 0) {
#if defined(_WIN32) || defined(_WIN64)
::fprintf(stderr, "Cannot create the UDP socket, err: %lu\n", ::GetLastError());
#else
::fprintf(stderr, "Cannot create the UDP socket, err: %d\n", errno);
#endif
return false;
}
if (m_port > 0U) {
sockaddr_in addr;
::memset(&addr, 0x00, sizeof(sockaddr_in));
addr.sin_family = AF_INET;
addr.sin_port = htons(m_port);
addr.sin_addr.s_addr = htonl(INADDR_ANY);
if (!m_address.empty()) {
#if defined(_WIN32) || defined(_WIN64)
addr.sin_addr.s_addr = ::inet_addr(m_address.c_str());
#else
addr.sin_addr.s_addr = ::inet_addr(m_address.c_str());
#endif
if (addr.sin_addr.s_addr == INADDR_NONE) {
::fprintf(stderr, "The local address is invalid - %s\n", m_address.c_str());
return false;
}
}
int reuse = 1;
if (::setsockopt(m_fd, SOL_SOCKET, SO_REUSEADDR, (char *)&reuse, sizeof(reuse)) == -1) {
#if defined(_WIN32) || defined(_WIN64)
::fprintf(stderr, "Cannot set the UDP socket option, err: %lu\n", ::GetLastError());
#else
::fprintf(stderr, "Cannot set the UDP socket option, err: %d\n", errno);
#endif
return false;
}
if (::bind(m_fd, (sockaddr*)&addr, sizeof(sockaddr_in)) == -1) {
#if defined(_WIN32) || defined(_WIN64)
::fprintf(stderr, "Cannot bind the UDP address, err: %lu\n", ::GetLastError());
#else
::fprintf(stderr, "Cannot bind the UDP address, err: %d\n", errno);
#endif
return false;
}
::fprintf(stdout, "Opening UDP port on %u\n", m_port);
}
return true;
}
int CUDPSocket::read(unsigned char* buffer, unsigned int length, in_addr& address, unsigned int& port)
{
assert(buffer != NULL);
assert(length > 0U);
// Check that the readfrom() won't block
fd_set readFds;
FD_ZERO(&readFds);
#if defined(_WIN32) || defined(_WIN64)
FD_SET((unsigned int)m_fd, &readFds);
#else
FD_SET(m_fd, &readFds);
#endif
// Return immediately
timeval tv;
tv.tv_sec = 0L;
tv.tv_usec = 0L;
int ret = ::select(m_fd + 1, &readFds, NULL, NULL, &tv);
if (ret < 0) {
#if defined(_WIN32) || defined(_WIN64)
::fprintf(stderr, "Error returned from UDP select, err: %lu\n", ::GetLastError());
#else
::fprintf(stderr, "Error returned from UDP select, err: %d\n", errno);
#endif
return -1;
}
if (ret == 0)
return 0;
sockaddr_in addr;
#if defined(_WIN32) || defined(_WIN64)
int size = sizeof(sockaddr_in);
#else
socklen_t size = sizeof(sockaddr_in);
#endif
#if defined(_WIN32) || defined(_WIN64)
int len = ::recvfrom(m_fd, (char*)buffer, length, 0, (sockaddr *)&addr, &size);
#else
ssize_t len = ::recvfrom(m_fd, (char*)buffer, length, 0, (sockaddr *)&addr, &size);
#endif
if (len <= 0) {
#if defined(_WIN32) || defined(_WIN64)
::fprintf(stderr, "Error returned from recvfrom, err: %lu\n", ::GetLastError());
#else
::fprintf(stderr, "Error returned from recvfrom, err: %d\n", errno);
#endif
return -1;
}
address = addr.sin_addr;
port = ntohs(addr.sin_port);
return len;
}
bool CUDPSocket::write(const unsigned char* buffer, unsigned int length, const in_addr& address, unsigned int port)
{
assert(buffer != NULL);
assert(length > 0U);
sockaddr_in addr;
::memset(&addr, 0x00, sizeof(sockaddr_in));
addr.sin_family = AF_INET;
addr.sin_addr = address;
addr.sin_port = htons(port);
#if defined(_WIN32) || defined(_WIN64)
int ret = ::sendto(m_fd, (char *)buffer, length, 0, (sockaddr *)&addr, sizeof(sockaddr_in));
#else
ssize_t ret = ::sendto(m_fd, (char *)buffer, length, 0, (sockaddr *)&addr, sizeof(sockaddr_in));
#endif
if (ret < 0) {
#if defined(_WIN32) || defined(_WIN64)
::fprintf(stderr, "Error returned from sendto, err: %lu\n", ::GetLastError());
#else
::fprintf(stderr, "Error returned from sendto, err: %d\n", errno);
#endif
return false;
}
#if defined(_WIN32) || defined(_WIN64)
if (ret != int(length))
return false;
#else
if (ret != ssize_t(length))
return false;
#endif
return true;
}
void CUDPSocket::close()
{
#if defined(_WIN32) || defined(_WIN64)
::closesocket(m_fd);
#else
::close(m_fd);
#endif
}