CSocket Class Reference

#include <UDPSocket.h>

Inheritance diagram for CSocket:

Public Types
enum	SocketType { TcpSocket = SOCK_STREAM, UdpSocket = SOCK_DGRAM, UnknownSocketType =-1 }
enum	NetworkLayerProtocol { IPv4Protocol = AF_INET, IPv6Protocol = AF_INET6, UnknownNetworkLayerProtocol = -1 }
enum	ReadResult { DATA_ARRIVED = 0, DATA_TIMED_OUT = ETIMEDOUT, DATA_EXCEPTION = 255 }

Public Member Functions
virtual	~CSocket ()
string	GetLocalAddress ()
unsigned short	GetLocalPort ()
void	BindLocalPort (unsigned short localPort)
void	BindLocalAddressAndPort (const string &localAddress, unsigned short localPort=0)
unsigned long int	GetReadBufferSize ()
void	SetReadBufferSize (unsigned int nSize)
void	SetNonBlocking (bool bBlocking)
void	ConnectToHost (const string &foreignAddress, unsigned short foreignPort)
void	Send (const void *buffer, int bufferLen)
int	Recv (void *buffer, int bufferLen)
string	GetPeerAddress ()
unsigned short	GetPeerPort ()
CSocket &	operator<< (const string &sStr)
CSocket &	operator>> (string &sStr)
virtual int	OnDataRead (unsigned long timeToWait=ULONG_MAX)
void	SetBindToDevice (const string &sInterface)

Protected Member Functions
	CSocket (SocketType type, NetworkLayerProtocol protocol)
	CSocket (int sockDesc)

Static Protected Member Functions
static void	FillAddr (const string &localAddress, unsigned short localPort, sockaddr_in &localAddr)

Protected Attributes
int	m_sockDesc

Private Member Functions
	CSocket (const CSocket &sock)
void	operator= (const CSocket &sock)

Detailed Description

Base class representing basic communication endpoint.

Definition at line 77 of file UDPSocket.h.

Member Enumeration Documentation

NetworkLayerProtocol

enum CSocket::NetworkLayerProtocol

Enum to represent type network layer protocol used for socket

Enumerator
IPv4Protocol
IPv6Protocol
UnknownNetworkLayerProtocol

Definition at line 95 of file UDPSocket.h.

    {
        IPv4Protocol = AF_INET,
        IPv6Protocol = AF_INET6,
        UnknownNetworkLayerProtocol = -1
    };

ReadResult

enum CSocket::ReadResult

Enum to represent Wait Result when reading data from a socket

Enumerator
DATA_ARRIVED
DATA_TIMED_OUT
DATA_EXCEPTION

Definition at line 105 of file UDPSocket.h.

    {
       DATA_ARRIVED   = 0,
       DATA_TIMED_OUT = ETIMEDOUT,
       DATA_EXCEPTION = 255
    };

SocketType

enum CSocket::SocketType

Enum to represent type of socket(UDP or TCP)

Enumerator
TcpSocket
UdpSocket
UnknownSocketType

Definition at line 85 of file UDPSocket.h.

    {
        TcpSocket = SOCK_STREAM,
        UdpSocket = SOCK_DGRAM,
        UnknownSocketType =-1
    };

Constructor & Destructor Documentation

~CSocket()

CSocket::~CSocket ( )

virtual

Definition at line 47 of file UDPSocket.cpp.

{
    ::close(m_sockDesc);
    m_sockDesc = -1;
}

CSocket() [1/3]

CSocket::CSocket ( SocketType  type, NetworkLayerProtocol  protocol  )

protected

Definition at line 53 of file UDPSocket.cpp.

References m_sockDesc.

                                                                :m_sockDesc(-1)
{
    m_sockDesc = socket(protocol, type, 0);
    if (m_sockDesc < 0)
    {
        throw CSocketException("Socket creation failed (socket())", true);
    }
}

CSocket() [2/3]

CSocket::CSocket ( int  sockDesc )

protected

Definition at line 62 of file UDPSocket.cpp.

References m_sockDesc.

{
    m_sockDesc = sockDesc;
}

CSocket() [3/3]

CSocket::CSocket ( const CSocket &  sock )

private

Definition at line 67 of file UDPSocket.cpp.

References m_sockDesc.

{
    m_sockDesc = sock.m_sockDesc;
}

Member Function Documentation

BindLocalAddressAndPort()

void CSocket::BindLocalAddressAndPort	(	const string &	localAddress,
		unsigned short	localPort = 0
	)

Set the local port to the specified port and the local address to the specified address. If you omit the port, a random port will be selected.

Parameters

localAddress	local address
localPort	local port

Exceptions

CSocketException

thrown if setting local port or address fails

Definition at line 113 of file UDPSocket.cpp.

References FillAddr(), and m_sockDesc.

Referenced by UDPSocket::UDPSocket().

{
    // Get the address of the requested host
    sockaddr_in localAddr;
    FillAddr(localAddress, localPort, localAddr);

    if (bind(m_sockDesc, (sockaddr *) &localAddr, sizeof(sockaddr_in)) < 0) {
        throw CSocketException("Set of local address and port failed (bind())", true);
    }
}

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BindLocalPort()

void CSocket::BindLocalPort

(

unsigned short

localPort

)

Set the local port to the specified port and the local address to any interface

Parameters

localPort

local port

Exceptions

CSocketException

thrown if setting local port fails

Definition at line 99 of file UDPSocket.cpp.

References m_sockDesc.

Referenced by UDPSocket::UDPSocket().

{
    // Bind the socket to its port
    sockaddr_in localAddr;
    memset(&localAddr, 0, sizeof(localAddr));
    localAddr.sin_family = AF_INET;
    localAddr.sin_addr.s_addr = htonl(INADDR_ANY);
    localAddr.sin_port = htons(localPort);

    if (bind(m_sockDesc, (sockaddr *) &localAddr, sizeof(sockaddr_in)) < 0) {
        throw CSocketException("Set of local port failed (bind())", true);
    }
}

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ConnectToHost()

void CSocket::ConnectToHost	(	const string &	foreignAddress,
		unsigned short	foreignPort
	)

Establish a socket connection with the given foreign address and port

Parameters

foreignAddress	foreign address (IP address or name)
foreignPort	foreign port

Exceptions

SocketException

thrown if unable to establish connection

Definition at line 176 of file UDPSocket.cpp.

References FillAddr(), and m_sockDesc.

{
    // Get the address of the requested host
    sockaddr_in destAddr;
    FillAddr(foreignAddress, foreignPort, destAddr);

    // Try to connect to the given port
    if (::connect(m_sockDesc, (sockaddr *) &destAddr, sizeof(destAddr)) < 0) {
        throw CSocketException("Connect failed (connect())", true);
    }
}

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FillAddr()

void CSocket::FillAddr ( const string &  localAddress, unsigned short  localPort, sockaddr_in &  localAddr  )

staticprotected

Definition at line 124 of file UDPSocket.cpp.

Referenced by BindLocalAddressAndPort(), ConnectToHost(), and UDPSocket::SendDataGram().

{
    memset(&localAddr, 0, sizeof(localAddr));  // Zero out address structure
    localAddr.sin_family = AF_INET;       // Internet address

    hostent *host;  // Resolve name
    if ((host = gethostbyname(localAddress.c_str())) == NULL) {
        // strerror() will not work for gethostbyname() and hstrerror()
        // is supposedly obsolete
        throw CSocketException("Failed to resolve name (gethostbyname())");
    }
    localAddr.sin_addr.s_addr = *((unsigned long *) host->h_addr_list[0]);

    localAddr.sin_port = htons(localPort);     // Assign port in network byte order
}

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GetLocalAddress()

std::string CSocket::GetLocalAddress

(

)

Get the local address

Returns

local address of socket

Exceptions

CSocketException

thrown if fetch fails

Definition at line 77 of file UDPSocket.cpp.

References m_sockDesc.

{
    sockaddr_in addr;
    unsigned int addr_len = sizeof(addr);

    if (getsockname(m_sockDesc, (sockaddr *) &addr, (socklen_t *) &addr_len) < 0) {
        throw CSocketException("Fetch of local address failed (getsockname())", true);
    }
    return inet_ntoa(addr.sin_addr);
}

GetLocalPort()

unsigned short CSocket::GetLocalPort

(

)

Get the local port

Returns

local port of socket

Exceptions

CSocketException

thrown if fetch fails

Definition at line 88 of file UDPSocket.cpp.

References m_sockDesc.

{
    sockaddr_in addr;
    unsigned int addr_len = sizeof(addr);

    if (getsockname(m_sockDesc, (sockaddr *) &addr, (socklen_t *) &addr_len) < 0) {
        throw CSocketException("Fetch of local port failed (getsockname())", true);
    }
    return ntohs(addr.sin_port);
}

GetPeerAddress()

std::string CSocket::GetPeerAddress

(

)

Get the foreign address. Call connect() before calling recv()

Returns

foreign address

Exceptions

SocketException

thrown if unable to fetch foreign address

Definition at line 206 of file UDPSocket.cpp.

References m_sockDesc.

{
    sockaddr_in addr;
    unsigned int addr_len = sizeof(addr);

    if (getpeername(m_sockDesc, (sockaddr *) &addr,(socklen_t *) &addr_len) < 0) {
        throw CSocketException("Fetch of foreign address failed (getpeername())", true);
    }
    return inet_ntoa(addr.sin_addr);
}

GetPeerPort()

unsigned short CSocket::GetPeerPort

(

)

Get the foreign port. Call connect() before calling recv()

Returns

foreign port

Exceptions

SocketException

thrown if unable to fetch foreign port

Definition at line 217 of file UDPSocket.cpp.

References m_sockDesc.

{
    sockaddr_in addr;
    unsigned int addr_len = sizeof(addr);

    if (getpeername(m_sockDesc, (sockaddr *) &addr, (socklen_t *) &addr_len) < 0) {
        throw CSocketException("Fetch of foreign port failed (getpeername())", true);
    }
    return ntohs(addr.sin_port);
}

GetReadBufferSize()

unsigned long int CSocket::GetReadBufferSize

(

)

Returns the size of the internal read buffer. This limits the amount of data that the client can receive before you call

Definition at line 140 of file UDPSocket.cpp.

References m_sockDesc.

Referenced by operator>>().

{
    unsigned long int nSize;
    socklen_t n = sizeof(nSize);
    getsockopt(m_sockDesc,SOL_SOCKET,SO_RCVBUF,(void *)&nSize, (&n));
    // now the variable nSize will have the socket size
    return nSize;
}

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OnDataRead()

int CSocket::OnDataRead ( unsigned long  timeToWait = ULONG_MAX )

virtual

Blocking function to check whether data arrived in socket for reading.

Parameters

timeToWait

waits for 'timeToWait' seconds.

Definition at line 243 of file UDPSocket.cpp.

References DATA_ARRIVED, DATA_EXCEPTION, DATA_TIMED_OUT, and m_sockDesc.

{
    /* master file descriptor list */
    fd_set master;

    /* temp file descriptor list for select() */
    fd_set read_fds;

    /* maximum file descriptor number */
    int fdmax;

    /* clear the master and temp sets */
    FD_ZERO(&master);
    FD_ZERO(&read_fds);

    /* add the listener to the master set */
    FD_SET(m_sockDesc, &master);
    /* keep track of the biggest file descriptor */
    fdmax = m_sockDesc; /* so far, it's this one*/

    /* copy it */
    read_fds = master;
    int nRet;

    if (timeToWait == ULONG_MAX)
    {
        nRet  = select(fdmax+1, &read_fds, NULL, NULL, NULL);
        if (nRet == -1)
            nRet = DATA_EXCEPTION;
        else if (nRet > 0)
            nRet = DATA_ARRIVED;
    }
    else
    {
        struct timeval       timeout;
        timeout.tv_sec  = timeToWait;
        timeout.tv_usec = 0;
        nRet = select(fdmax+1, &read_fds, NULL, NULL, &timeout);
        if (nRet == -1)
            nRet = DATA_EXCEPTION;
        else if (nRet > 0)
            nRet = DATA_ARRIVED;
        else if(nRet == 0)
            nRet = DATA_TIMED_OUT;
    }

    return nRet;
}

operator<<()

CSocket & CSocket::operator<<

(

const string &

sStr

)

Writing sStr to socket

Definition at line 228 of file UDPSocket.cpp.

References Send().

{
     Send(sStr.c_str(), sStr.length());
     return *this;
}

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operator=()

void CSocket::operator= ( const CSocket &  sock )

private

Definition at line 72 of file UDPSocket.cpp.

References m_sockDesc.

{
    m_sockDesc = sock.m_sockDesc;
}

operator>>()

CSocket & CSocket::operator>>

(

string &

sStr

)

Reading data to sStr from socket

Definition at line 234 of file UDPSocket.cpp.

References GetReadBufferSize(), and Recv().

{
    char *buff = new char[GetReadBufferSize()];
    Recv(buff, GetReadBufferSize());
    sStr.append(buff);
    delete [] buff;
    return *this;
}

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Recv()

int CSocket::Recv	(	void *	buffer,
		int	bufferLen
	)

Read into the given buffer up to bufferLen bytes data from this socket. Call connect() before calling recv()

Parameters

buffer	buffer to receive the data
bufferLen	maximum number of bytes to read into buffer

Returns

number of bytes read, 0 for EOF, and -1 for error

Exceptions

SocketException

thrown if unable to receive data

Definition at line 195 of file UDPSocket.cpp.

References m_sockDesc.

Referenced by operator>>().

{
    int nBytes;
    if ((nBytes = ::recv(m_sockDesc, (void *) buffer, bufferLen, 0)) < 0) {
        throw CSocketException("Received failed (recv())", true);
    }
    char* sData = static_cast<char *>(buffer);
    sData[nBytes] = '\0';
    return nBytes;
}

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Send()

void CSocket::Send	(	const void *	buffer,
		int	bufferLen
	)

Write the given buffer to this socket. Call connect() before calling send()

Parameters

buffer	buffer to be written
bufferLen	number of bytes from buffer to be written

Exceptions

SocketException

thrown if unable to send data

Definition at line 188 of file UDPSocket.cpp.

References m_sockDesc.

Referenced by operator<<().

{
    if (::send(m_sockDesc, (void *) buffer, bufferLen, 0) < 0) {
        throw CSocketException("Send failed (send())", true);
    }
}

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SetBindToDevice()

void CSocket::SetBindToDevice

(

const string &

sInterface

)

To Bind socket to a symbolic device name like eth0

Parameters

sInterface

NIC device name

Definition at line 292 of file UDPSocket.cpp.

{
    struct ifreq ifr;
    memset(&ifr, 0, sizeof(ifr));
    snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s", sInterface.c_str());
}

SetNonBlocking()

void CSocket::SetNonBlocking

(

bool

bBlocking

)

Sets the socket to Blocking/Non blocking state.

Parameters

Bool	flag for Non blocking status.

Definition at line 157 of file UDPSocket.cpp.

References m_sockDesc.

{
    int opts;

    opts = fcntl ( m_sockDesc, F_GETFL );

    if ( opts < 0 )
    {
        return;
    }

    if ( bBlocking )
        opts = ( opts | O_NONBLOCK );
    else
        opts = ( opts & ~O_NONBLOCK );

    fcntl ( m_sockDesc, F_SETFL,opts );
}

SetReadBufferSize()

void CSocket::SetReadBufferSize

(

unsigned int

nSize

)

Sets the read buffer size of the socket.

Parameters

Size	of the buffer.

Definition at line 149 of file UDPSocket.cpp.

References m_sockDesc.

{
    if (setsockopt(m_sockDesc, SOL_SOCKET, SO_RCVBUF, &nSize, sizeof(nSize)) == -1)
    {
        throw CSocketException("Error in setting socket buffer size ", true);
    }
}

Member Data Documentation

m_sockDesc

int CSocket::m_sockDesc

protected

Internal Socket descriptor

Definition at line 235 of file UDPSocket.h.

Referenced by BindLocalAddressAndPort(), BindLocalPort(), ConnectToHost(), CSocket(), UDPSocket::DisconnectFromHost(), GetLocalAddress(), GetLocalPort(), GetPeerAddress(), GetPeerPort(), GetReadBufferSize(), UDPSocket::JoinGroup(), UDPSocket::LeaveGroup(), OnDataRead(), operator=(), Recv(), UDPSocket::RecvDataGram(), Send(), UDPSocket::SendDataGram(), UDPSocket::SetBroadcast(), UDPSocket::SetMulticastTTL(), SetNonBlocking(), and SetReadBufferSize().

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The documentation for this class was generated from the following files:

• plugins/samplesink/remoteoutput/UDPSocket.h
• plugins/samplesink/remoteoutput/UDPSocket.cpp