dlib C++ Library - sockets_kernel_2.cpp
// Copyright (C) 2003 Davis E. King (davis@dlib.net), Miguel Grinberg
// License: Boost Software License See LICENSE.txt for the full license.
#ifndef DLIB_SOCKETS_KERNEL_2_CPp_
#define DLIB_SOCKETS_KERNEL_2_CPp_
#include "../platform.h"
#ifdef DLIB_POSIX
#include "sockets_kernel_2.h"
#include <fcntl.h>
#include "../set.h"
#include <netinet/tcp.h>
#include <string.h>
namespace dlib
{
// ----------------------------------------------------------------------------------------
#ifdef HPUX
typedef int dsocklen_t;
#else
typedef socklen_t dsocklen_t;
#endif
// ----------------------------------------------------------------------------------------
// stuff to ensure that the signal SIGPIPE is ignored before any connections are made
// so that when a connection object is shutdown the program won't end on a broken pipe
namespace sockets_kernel_2_mutex
{
mutex startup_lock;
}
void sockets_startup()
{
// mutex crap to make this function thread safe
sockets_kernel_2_mutex::startup_lock.lock();
static bool init = false;
if (init == false)
{
init = true;
signal( SIGPIPE, SIG_IGN);
}
sockets_kernel_2_mutex::startup_lock.unlock();
}
// ----------------------------------------------------------------------------------------
// lookup functions
int
get_local_hostname (
std::string& hostname
)
{
try
{
char temp[MAXHOSTNAMELEN];
if (gethostname(temp,MAXHOSTNAMELEN) == -1)
{
return OTHER_ERROR;
}
// ensure that NUL is at the end of the string
temp[MAXHOSTNAMELEN-1] = '0円';
hostname = temp;
}
catch (...)
{
return OTHER_ERROR;
}
return 0;
}
// -----------------
// cygwin currently doesn't support the getaddrinfo stuff
#ifndef __CYGWIN__
int
hostname_to_ip (
const std::string& hostname,
std::string& ip,
int n
)
{
try
{
set<std::string>::kernel_1a sos;
if (hostname.empty())
return OTHER_ERROR;
addrinfo* result = 0;
if (getaddrinfo(hostname.c_str(),0,0,&result))
{
return OTHER_ERROR;
}
addrinfo* result_orig = result;
// loop over all the addrinfo structures and add them to the set. the reason for doing
// this dumb crap is because different platforms return all kinds of weird garbage. many
// return the same ip multiple times, etc.
while (result != 0)
{
char temp[16];
inet_ntop (
AF_INET,
&((reinterpret_cast<sockaddr_in*>(result->ai_addr))->sin_addr),
temp,16
);
result = result->ai_next;
ip.assign(temp);
if (sos.is_member(ip) == false && ip != "0.0.0.0")
sos.add(ip);
}
freeaddrinfo(result_orig);
// now return the nth unique ip address
int i = 0;
while (sos.move_next())
{
if (i == n)
{
ip = sos.element();
return 0;
}
++i;
}
return OTHER_ERROR;
}
catch (...)
{
return OTHER_ERROR;
}
return 0;
}
// -----------------
int
ip_to_hostname (
const std::string& ip,
std::string& hostname
)
{
try
{
if (ip.empty())
return OTHER_ERROR;
sockaddr_in sa;
sa.sin_family = AF_INET;
inet_pton(AF_INET,ip.c_str(),&sa.sin_addr);
char temp[NI_MAXHOST];
if ( getnameinfo (
reinterpret_cast<sockaddr*>(&sa),sizeof(sockaddr_in),
temp,
NI_MAXHOST,
0,
0,
NI_NAMEREQD
)
)
{
return OTHER_ERROR;
}
hostname.assign(temp);
}
catch (...)
{
return OTHER_ERROR;
}
return 0;
}
#else
int
hostname_to_ip (
const std::string& hostname,
std::string& ip,
int n
)
{
try
{
// lock this mutex since gethostbyname isn't really thread safe
auto_mutex M(sockets_kernel_2_mutex::startup_lock);
// if no hostname was given then return error
if ( hostname.empty())
return OTHER_ERROR;
hostent* address;
address = gethostbyname(hostname.c_str());
if (address == 0)
{
return OTHER_ERROR;
}
// find the nth address
in_addr* addr = reinterpret_cast<in_addr*>(address->h_addr_list[0]);
for (int i = 1; i <= n; ++i)
{
addr = reinterpret_cast<in_addr*>(address->h_addr_list[i]);
// if there is no nth address then return error
if (addr == 0)
return OTHER_ERROR;
}
char* resolved_ip = inet_ntoa(*addr);
// check if inet_ntoa returned an error
if (resolved_ip == NULL)
{
return OTHER_ERROR;
}
ip.assign(resolved_ip);
}
catch(...)
{
return OTHER_ERROR;
}
return 0;
}
// -----------------
int
ip_to_hostname (
const std::string& ip,
std::string& hostname
)
{
try
{
// lock this mutex since gethostbyaddr isn't really thread safe
auto_mutex M(sockets_kernel_2_mutex::startup_lock);
// if no ip was given then return error
if (ip.empty())
return OTHER_ERROR;
hostent* address;
unsigned long ipnum = inet_addr(ip.c_str());
// if inet_addr couldn't convert ip then return an error
if (ipnum == INADDR_NONE)
{
return OTHER_ERROR;
}
address = gethostbyaddr(reinterpret_cast<char*>(&ipnum),4,AF_INET);
// check if gethostbyaddr returned an error
if (address == 0)
{
return OTHER_ERROR;
}
hostname.assign(address->h_name);
}
catch (...)
{
return OTHER_ERROR;
}
return 0;
}
#endif // __CYGWIN__
// ----------------------------------------------------------------------------------------
connection::
connection(
int sock,
int foreign_port,
const std::string& foreign_ip,
int local_port,
const std::string& local_ip
) :
connection_socket(sock),
connection_foreign_port(foreign_port),
connection_foreign_ip(foreign_ip),
connection_local_port(local_port),
connection_local_ip(local_ip),
sd(false),
sdo(false),
sdr(0)
{}
// ----------------------------------------------------------------------------------------
int connection::
disable_nagle()
{
int flag = 1;
if(setsockopt( connection_socket, IPPROTO_TCP, TCP_NODELAY, (char *)&flag, sizeof(flag) ))
{
return OTHER_ERROR;
}
return 0;
}
// ----------------------------------------------------------------------------------------
long connection::
write (
const char* buf,
long num
)
{
const long old_num = num;
long status;
const long max_send_length = 1024*1024*100;
while (num > 0)
{
// Make sure to cap the max value num can take on so that if it is
// really large (it might be big on 64bit platforms) so that the OS
// can't possibly get upset about it being large.
const long length = std::min(max_send_length, num);
if ( (status = ::send(connection_socket,buf,length,0)) <=0)
{
// if send was interupted by a signal then restart it
if (errno == EINTR)
{
continue;
}
else
{
// check if shutdown or shutdown_outgoing have been called
if (sdo_called())
return SHUTDOWN;
else
return OTHER_ERROR;
}
}
num -= status;
buf += status;
}
return old_num;
}
// ----------------------------------------------------------------------------------------
long connection::
read (
char* buf,
long num
)
{
long status;
const long max_recv_length = 1024*1024*100;
while (true)
{
// Make sure to cap the max value num can take on so that if it is
// really large (it might be big on 64bit platforms) so that the OS
// can't possibly get upset about it being large.
const long length = std::min(max_recv_length, num);
status = recv(connection_socket,buf,length,0);
if (status == -1)
{
// if recv was interupted then try again
if (errno == EINTR)
continue;
else
{
if (sd_called())
return SHUTDOWN;
else
return OTHER_ERROR;
}
}
else if (status == 0 && sd_called())
{
return SHUTDOWN;
}
return status;
} // while (true)
}
// ----------------------------------------------------------------------------------------
long connection::
read (
char* buf,
long num,
unsigned long timeout
)
{
long status;
const long max_recv_length = 1024*1024*100;
if (readable(timeout) == false)
return TIMEOUT;
// Make sure to cap the max value num can take on so that if it is
// really large (it might be big on 64bit platforms) so that the OS
// can't possibly get upset about it being large.
const long length = std::min(max_recv_length, num);
status = recv(connection_socket,buf,length,0);
if (status == -1)
{
// if recv was interupted then call this a timeout
if (errno == EINTR)
{
return TIMEOUT;
}
else
{
if (sd_called())
return SHUTDOWN;
else
return OTHER_ERROR;
}
}
else if (status == 0 && sd_called())
{
return SHUTDOWN;
}
return status;
}
// ----------------------------------------------------------------------------------------
bool connection::
readable (
unsigned long timeout
) const
{
fd_set read_set;
// initialize read_set
FD_ZERO(&read_set);
// add the listening socket to read_set
FD_SET(connection_socket, &read_set);
// setup a timeval structure
timeval time_to_wait;
time_to_wait.tv_sec = static_cast<long>(timeout/1000);
time_to_wait.tv_usec = static_cast<long>((timeout%1000)*1000);
// wait on select
int status = select(connection_socket+1,&read_set,0,0,&time_to_wait);
// if select timed out or there was an error
if (status <= 0)
return false;
// socket is ready to be read
return true;
}
// ----------------------------------------------------------------------------------------
connection::
~connection (
)
{
while (true)
{
int status = ::close(connection_socket);
if (status == -1 && errno == EINTR)
continue;
break;
}
}
// ----------------------------------------------------------------------------------------
// ----------------------------------------------------------------------------------------
// listener object
// ----------------------------------------------------------------------------------------
// ----------------------------------------------------------------------------------------
listener::
listener(
int sock,
int port,
const std::string& ip
) :
listening_socket(sock),
listening_port(port),
listening_ip(ip),
inaddr_any(listening_ip.empty())
{}
// ----------------------------------------------------------------------------------------
listener::
~listener (
)
{
while (true)
{
int status = ::close(listening_socket);
if (status == -1 && errno == EINTR)
continue;
break;
}
}
// ----------------------------------------------------------------------------------------
int listener::
accept (
std::unique_ptr<connection>& new_connection,
unsigned long timeout
)
{
new_connection.reset(0);
connection* con;
int status = this->accept(con, timeout);
if (status == 0)
new_connection.reset(con);
return status;
}
// ----------------------------------------------------------------------------------------
int listener::
accept (
connection*& new_connection,
unsigned long timeout
)
{
int incoming;
sockaddr_in incomingAddr;
dsocklen_t length = sizeof(sockaddr_in);
// implement timeout with select if timeout is > 0
if (timeout > 0)
{
fd_set read_set;
// initialize read_set
FD_ZERO(&read_set);
// add the listening socket to read_set
FD_SET(listening_socket, &read_set);
timeval time_to_wait;
// loop on select so if its interupted then we can start it again
while (true)
{
// setup a timeval structure
time_to_wait.tv_sec = static_cast<long>(timeout/1000);
time_to_wait.tv_usec = static_cast<long>((timeout%1000)*1000);
// wait on select
int status = select(listening_socket+1,&read_set,0,0,&time_to_wait);
// if select timed out
if (status == 0)
return TIMEOUT;
// if select returned an error
if (status == -1)
{
// if select was interupted or the connection was aborted
// then go back to select
if (errno == EINTR ||
errno == ECONNABORTED ||
#ifdef EPROTO
errno == EPROTO ||
#endif
errno == ECONNRESET
)
{
continue;
}
else
{
return OTHER_ERROR;
}
}
// accept the new connection
incoming=::accept (
listening_socket,
reinterpret_cast<sockaddr*>(&incomingAddr),
&length
);
// if there was an error return OTHER_ERROR
if ( incoming == -1 )
{
// if accept was interupted then go back to accept
if (errno == EINTR ||
errno == ECONNABORTED ||
#ifdef EPROTO
errno == EPROTO ||
#endif
errno == ECONNRESET
)
{
continue;
}
else
{
return OTHER_ERROR;
}
}
// if there were no errors then quit loop
break;
}
}
// else if there is no time out then just go into accept
else
{
while (true)
{
// call accept to get a new connection
incoming=::accept (
listening_socket,
reinterpret_cast<sockaddr*>(&incomingAddr),
&length
);
// if there was an error return OTHER_ERROR
if ( incoming == -1 )
{
// if accept was interupted then go back to accept
if (errno == EINTR ||
errno == ECONNABORTED ||
#ifdef EPROTO
errno == EPROTO ||
#endif
errno == ECONNRESET
)
{
continue;
}
else
{
return OTHER_ERROR;
}
}
break;
}
}
// get the port of the foreign host into foreign_port
int foreign_port = ntohs(incomingAddr.sin_port);
// get the IP of the foreign host into foreign_ip
char foreign_ip[16];
inet_ntop(AF_INET,&incomingAddr.sin_addr,foreign_ip,16);
// get the local ip for this connection into local_ip
char temp_local_ip[16];
std::string local_ip;
if (inaddr_any == true)
{
sockaddr_in local_info;
length = sizeof(sockaddr_in);
// get the local sockaddr_in structure associated with this new connection
if ( getsockname (
incoming,
reinterpret_cast<sockaddr*>(&local_info),
&length
) == -1
)
{ // an error occurred
while (true)
{
int status = ::close(incoming);
if (status == -1 && errno == EINTR)
continue;
break;
}
return OTHER_ERROR;
}
local_ip = const_cast<char*> (
inet_ntop(AF_INET,&local_info.sin_addr,temp_local_ip,16)
);
}
else
{
local_ip = listening_ip;
}
// set the SO_OOBINLINE option
int flag_value = 1;
if (setsockopt(incoming,SOL_SOCKET,SO_OOBINLINE,reinterpret_cast<const void*>(&flag_value),sizeof(int)))
{
while (true)
{
int status = ::close(incoming);
if (status == -1 && errno == EINTR)
continue;
break;
}
return OTHER_ERROR;
}
// make a new connection object for this new connection
try
{
new_connection = new connection (
incoming,
foreign_port,
foreign_ip,
listening_port,
local_ip
);
}
catch (...)
{
while (true)
{
int status = ::close(incoming);
if (status == -1 && errno == EINTR)
continue;
break;
}
return OTHER_ERROR;
}
return 0;
}
// ----------------------------------------------------------------------------------------
// ----------------------------------------------------------------------------------------
// socket creation functions
// ----------------------------------------------------------------------------------------
// ----------------------------------------------------------------------------------------
static void
close_socket (
int sock
)
/*!
requires
- sock == a socket
ensures
- sock has been closed
!*/
{
while (true)
{
int status = ::close(sock);
if (status == -1 && errno == EINTR)
continue;
break;
}
}
// ----------------------------------------------------------------------------------------
int create_listener (
std::unique_ptr<listener>& new_listener,
unsigned short port,
const std::string& ip
)
{
new_listener.reset();
listener* temp;
int status = create_listener(temp,port,ip);
if (status == 0)
new_listener.reset(temp);
return status;
}
int create_listener (
listener*& new_listener,
unsigned short port,
const std::string& ip
)
{
sockets_startup();
sockaddr_in sa; // local socket structure
memset(&sa,'0円',sizeof(sockaddr_in)); // initialize sa
int sock = socket (AF_INET, SOCK_STREAM, 0); // get a new socket
// if socket() returned an error then return OTHER_ERROR
if (sock == -1)
{
return OTHER_ERROR;
}
// set the local socket structure
sa.sin_family = AF_INET;
sa.sin_port = htons(port);
if (ip.empty())
{
// if the listener should listen on any IP
sa.sin_addr.s_addr = htons(INADDR_ANY);
}
else
{
// if there is a specific ip to listen on
sa.sin_addr.s_addr = inet_addr(ip.c_str());
// if inet_addr couldn't convert the ip then return an error
if ( sa.sin_addr.s_addr == ( in_addr_t)(-1))
{
close_socket(sock);
return OTHER_ERROR;
}
}
// set the SO_REUSEADDR option
int flag_value = 1;
if (setsockopt(sock,SOL_SOCKET,SO_REUSEADDR,reinterpret_cast<const void*>(&flag_value),sizeof(int)))
{
close_socket(sock);
return OTHER_ERROR;
}
// bind the new socket to the requested port and ip
if (bind(sock,reinterpret_cast<sockaddr*>(&sa),sizeof(sockaddr_in)) == -1)
{ // if there was an error
close_socket(sock);
// if the port is already bound then return PORTINUSE
if (errno == EADDRINUSE)
return PORTINUSE;
else
return OTHER_ERROR;
}
// tell the new socket to listen
if ( listen(sock,SOMAXCONN) == -1)
{
// if there was an error return OTHER_ERROR
close_socket(sock);
// if the port is already bound then return PORTINUSE
if (errno == EADDRINUSE)
return PORTINUSE;
else
return OTHER_ERROR;
}
// determine the used local port if necessary
if (port == 0)
{
sockaddr_in local_info;
dsocklen_t length = sizeof(sockaddr_in);
if ( getsockname(
sock,
reinterpret_cast<sockaddr*>(&local_info),
&length
) == -1)
{
close_socket(sock);
return OTHER_ERROR;
}
port = ntohs(local_info.sin_port);
}
// initialize a listener object on the heap with the new socket
try { new_listener = new listener(sock,port,ip); }
catch(...) { close_socket(sock); return OTHER_ERROR; }
return 0;
}
// ----------------------------------------------------------------------------------------
int create_connection (
std::unique_ptr<connection>& new_connection,
unsigned short foreign_port,
const std::string& foreign_ip,
unsigned short local_port,
const std::string& local_ip
)
{
new_connection.reset();
connection* temp;
int status = create_connection(temp,foreign_port, foreign_ip, local_port, local_ip);
if (status == 0)
new_connection.reset(temp);
return status;
}
int
create_connection (
connection*& new_connection,
unsigned short foreign_port,
const std::string& foreign_ip,
unsigned short local_port,
const std::string& local_ip
)
{
sockets_startup();
sockaddr_in local_sa; // local socket structure
sockaddr_in foreign_sa; // foreign socket structure
memset(&local_sa,'0円',sizeof(sockaddr_in)); // initialize local_sa
memset(&foreign_sa,'0円',sizeof(sockaddr_in)); // initialize foreign_sa
dsocklen_t length;
int sock = socket (AF_INET, SOCK_STREAM, 0); // get a new socket
// if socket() returned an error then return OTHER_ERROR
if (sock == -1 )
{
return OTHER_ERROR;
}
// set the foreign socket structure
foreign_sa.sin_family = AF_INET;
foreign_sa.sin_port = htons(foreign_port);
foreign_sa.sin_addr.s_addr = inet_addr(foreign_ip.c_str());
// if inet_addr couldn't convert the ip then return an error
if ( foreign_sa.sin_addr.s_addr == ( in_addr_t)(-1))
{
close_socket(sock);
return OTHER_ERROR;
}
// set up the local socket structure
local_sa.sin_family = AF_INET;
// set the local port
local_sa.sin_port = htons(local_port);
// set the local ip
if (local_ip.empty())
{
// if the listener should listen on any IP
local_sa.sin_addr.s_addr = htons(INADDR_ANY);
}
else
{
// if there is a specific ip to listen on
local_sa.sin_addr.s_addr = inet_addr(local_ip.c_str());
// if inet_addr couldn't convert the ip then return an error
if ( local_sa.sin_addr.s_addr == ( in_addr_t)(-1))
{
close_socket(sock);
return OTHER_ERROR;
}
}
// bind the new socket to the requested local port and local ip
if ( bind(sock,reinterpret_cast<sockaddr*>(&local_sa),sizeof(sockaddr_in)) == -1)
{ // if there was an error
close_socket(sock);
// if the port is already bound then return PORTINUSE
if (errno == EADDRINUSE)
return PORTINUSE;
else
return OTHER_ERROR;
}
// connect the socket
if ( connect (
sock,
reinterpret_cast<sockaddr*>(&foreign_sa),
sizeof(sockaddr_in)
) == -1
)
{
close_socket(sock);
// if the port is already bound then return PORTINUSE
if (errno == EADDRINUSE)
return PORTINUSE;
else
return OTHER_ERROR;
}
// determine the local port and IP and store them in used_local_ip
// and used_local_port
int used_local_port;
char temp_used_local_ip[16];
std::string used_local_ip;
sockaddr_in local_info;
// determine the port
if (local_port == 0)
{
length = sizeof(sockaddr_in);
if ( getsockname(
sock,
reinterpret_cast<sockaddr*>(&local_info),
&length
) == -1)
{
close_socket(sock);
return OTHER_ERROR;
}
used_local_port = ntohs(local_info.sin_port);
}
else
{
used_local_port = local_port;
}
// determine the ip
if (local_ip.empty())
{
// if local_port is not 0 then we must fill the local_info structure
if (local_port != 0)
{
length = sizeof(sockaddr_in);
if ( getsockname (
sock,
reinterpret_cast<sockaddr*>(&local_info),
&length
) == -1
)
{
close_socket(sock);
return OTHER_ERROR;
}
}
used_local_ip = inet_ntop(AF_INET,&local_info.sin_addr,temp_used_local_ip,16);
}
else
{
used_local_ip = local_ip;
}
// set the SO_OOBINLINE option
int flag_value = 1;
if (setsockopt(sock,SOL_SOCKET,SO_OOBINLINE,reinterpret_cast<const void*>(&flag_value),sizeof(int)))
{
close_socket(sock);
return OTHER_ERROR;
}
// initialize a connection object on the heap with the new socket
try
{
new_connection = new connection (
sock,
foreign_port,
foreign_ip,
used_local_port,
used_local_ip
);
}
catch(...) {close_socket(sock); return OTHER_ERROR; }
return 0;
}
// ----------------------------------------------------------------------------------------
}
#endif // DLIB_POSIX
#endif // DLIB_SOCKETS_KERNEL_2_CPp_