tcp Namespace Reference

A tcp client/server library for linux that supports openSSL and EPoll. More...

Classes
class	Client
	A blocking or non-blocking TCP client connection. More...
class	DataSocket
	Represents a buffered socket that can send and receive data using optional SSL encryption. More...
class	EPoll
	Encapsulates the EPoll interface. More...
class	Server
	Listens for TCP connections and establishes Sessions. More...
class	Session
	Represents a TCP connection accepted by the Server. More...
class	Socket
	Encapsulates a socket handle that is capable of recieving epoll events. More...
class	SSL
	Encapsulates an SSL connection data structure. More...
class	SSLContext
	Encapsulates an openSSL SSL_CTX record. More...

Enumerations
enum	SocketState {   UNCONNECTED =0, LISTENING, CONNECTING, CONNECTED,   DISCONNECTED }
	Determines the state of a socket. More...
enum	SSLMode { CLIENT, SERVER }

Functions
ostream	logstream (clog.rdbuf())
void	setLogStream (ostream *os)
	Set the output stream used by the library for log, warning and error messages. More...
void	error (string msg)
	Send an error message to the log stream.
void	error (string label, string msg)
	Send a labelled error message to the log stream.
void	warning (string msg)
	Send a warning message to the log stream.
void	warning (string label, string msg)
	Send an labelled warning message to the log stream.
void	log (string msg)
	Send an log message to the log stream.
void	log (string label, string msg)
	Send a labelled log message to the log stream.
int	getDomainFromHostAndPort (const char *host, const char *port, int def_domain=AF_INET)
	Tries to determine which address family to use from a host and port string. More...
void	initSSLLibrary ()
	Initialize the openSSL library. More...
void	freeSSLLibrary ()
	Free up resources created by the openSSL library. More...
void	print_error_string (unsigned long err, const char *const label)
int	printSSLErrors_cb (const char *str, size_t len, void *u)
void	printSSLErrors ()
	This method logs openSSL errors to cerr.
int	wildcmp (const char *wild, const char *string)
	Wildcard compare function. More...
void	print_cn_name (const char *label, X509_NAME *const name)
	Prints the certificate common name to clog.
void	print_san_name (const char *label, X509 *const cert)
	Prints the certificate subject alt name to clog.
int	verify_callback (int preverify, X509_STORE_CTX *x509_ctx)
	Prints the certificate details to clog.
int	ctx_password_callback (char *buf, int size, int rwflag, void *userdata)
int	ssl_password_callback (char *buf, int size, int rwflag, void *userdata)

Variables
bool	sslinitialized_ {false}

Detailed Description

A tcp client/server library for linux that supports openSSL and EPoll.

Enumeration Type Documentation

SocketState

enum tcp::SocketState

strong

Determines the state of a socket.

Not all states are valid for every socket type.

Definition at line 58 of file tcpsocket.h.

{UNCONNECTED=0, LISTENING, CONNECTING, CONNECTED, DISCONNECTED};

Function Documentation

freeSSLLibrary()

void tcp::freeSSLLibrary

(

)

Free up resources created by the openSSL library.

Applications should call this method at application shutdown.

Definition at line 32 of file tcpssl.cpp.

{
  ERR_free_strings();
}

getDomainFromHostAndPort()

int tcp::getDomainFromHostAndPort	(	const char *	host,
		const char *	port,
		int	def_domain = AF_INET
	)

Tries to determine which address family to use from a host and port string.

If host is other than a numeric address, the address family will be detemined through a canonical name lookup

Returns

AF_INET or AF_INET6 if an address family can be determined, AF_UNSPEC otherwise

Definition at line 357 of file tcpsocket.cpp.

{
  struct addrinfo hints;
  struct addrinfo *result;
  int errorcode;
  int domain;
 
  memset(&hints,0,sizeof(struct addrinfo));
  hints.ai_family = AF_UNSPEC;
  hints.ai_flags = AI_NUMERICHOST;
  errorcode = getaddrinfo(host,nullptr,&hints,&result);
  if (errorcode == 0) {
    domain = result->ai_family;
  } else {
    domain = AF_UNSPEC;
  }
  if (domain == AF_UNSPEC) {
    hints.ai_flags = AI_CANONNAME;
    errorcode = getaddrinfo(host,port,&hints,&result);
    if (errorcode == 0) {
      domain = result->ai_family;
    }
  }
  if (domain == AF_UNSPEC) {
    return def_domain;
  } else {
    return domain;
  }
}

initSSLLibrary()

void tcp::initSSLLibrary

(

)

Initialize the openSSL library.

Applications should call this method once at application startup. It must be called before any other openSSL library functions are called.

Definition at line 19 of file tcpssl.cpp.

{
  if (!sslinitialized_) {
    SSL_library_init();             
    OpenSSL_add_all_algorithms();
    SSL_load_error_strings();
    ERR_load_crypto_strings();
    OpenSSL_add_all_ciphers();
    sslinitialized_ = true;
    clog << "OpenSSL library initialized" << endl;
  }
}

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setLogStream()

void tcp::setLogStream

(

ostream *

os

)

Set the output stream used by the library for log, warning and error messages.

Defaults to clog

Definition at line 17 of file tcpsocket.cpp.

{ if (os) logstream.rdbuf(os->rdbuf()); }

wildcmp()

int tcp::wildcmp	(	const char *	wild,
		const char *	string
	)

Wildcard compare function.

This compare function performs comparisons against a string using the * and ? wildcard characters.

Remarks

Used internally to validate that hostName matches a certificate subjectName. Exposed because it might be useful elsewhere in a program.

Definition at line 62 of file tcpssl.cpp.

                                                  {
  // Written by Jack Handy - <A href="mailto:jakkhandy@hotmail.com">jakkhandy@hotmail.com</A>
  const char *cp = NULL, *mp = NULL;
 
  while ((*string) && (*wild != '*')) {
    if ((*wild != *string) && (*wild != '?')) {
      return 0;
    }
    wild++;
    string++;
  }
 
  while (*string) {
    if (*wild == '*') {
      if (!*++wild) {
        return 1;
      }
      mp = wild;
      cp = string+1;
    } else if ((*wild == *string) || (*wild == '?')) {
      wild++;
      string++;
    } else {
      wild = mp;
      string = cp++;
    }
  }
 
  while (*wild == '*') {
    wild++;
  }
  return !*wild;
}

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