Hamlib/src/network.c

/*
 *  Hamlib Interface - network communication low-level support
 *  Copyright (c) 2000-2012 by Stephane Fillod
 *
 *   This library is free software; you can redistribute it and/or
 *   modify it under the terms of the GNU Lesser General Public
 *   License as published by the Free Software Foundation; either
 *   version 2.1 of the License, or (at your option) any later version.
 *
 *   This library 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
 *   Lesser General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public
 *   License along with this library; if not, write to the Free Software
 *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

/**
 * \addtogroup rig_internal
 * @{
 */

/**
 * \brief Network port IO
 * \file network.c
 */

/* Forcing WINVER in MinGW yanks in getaddrinfo(), but locks out Win95/Win98 */
/* #define WINVER 0x0501 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <stdlib.h>
#include <stdio.h>   /* Standard input/output definitions */
#include <string.h>  /* String function definitions */
#include <unistd.h>  /* UNIX standard function definitions */
#include <fcntl.h>   /* File control definitions */
#include <errno.h>   /* Error number definitions */
#include <sys/time.h>
#include <sys/types.h>
#include <signal.h>
#include <sys/ioctl.h>


#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#if HAVE_NETDB_H
#include <netdb.h>
#endif
#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#elif HAVE_WS2TCPIP_H
#include <ws2tcpip.h>
#	if defined(HAVE_WSPIAPI_H)
#		include <wspiapi.h>
#	endif
#endif

#include "hamlib/rig.h"
#include "network.h"
#include "misc.h"


#ifdef __MINGW32__
static int wsstarted;
#endif

#define NET_BUFFER_SIZE 64

static void handle_error (enum rig_debug_level_e lvl, const char *msg)
{
	int e;
#ifdef __MINGW32__
	LPVOID lpMsgBuf;

	lpMsgBuf = (LPVOID)"Unknown error";
	e = WSAGetLastError();
	if (FormatMessage(
			FORMAT_MESSAGE_ALLOCATE_BUFFER |
			FORMAT_MESSAGE_FROM_SYSTEM |
			FORMAT_MESSAGE_IGNORE_INSERTS,
			NULL, e,
			MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
				// Default language
			(LPTSTR)&lpMsgBuf, 0, NULL))
		{
			rig_debug (lvl, "%s: Network error %d: %s\n", msg, e, lpMsgBuf);
			LocalFree(lpMsgBuf);
		}
	else
		{
			rig_debug (lvl, "%s: Network error %d\n", msg, e);
		}
#else
	e = errno;
	rig_debug (lvl, "%s: Network error %d: %s\n", msg, e, strerror (e));
#endif
}

/**
 * \brief Clears any data in the read buffer of the socket
 *
 * \param rp Port data structure
 */
void network_flush(hamlib_port_t* rp)
{
  int len = 0;
  char buffer[NET_BUFFER_SIZE] = { 0 };
  for (;;) {
    ioctl(rp->fd, FIONREAD, &len);
    if (len > 0) {
      len = read(rp->fd, &buffer, len < NET_BUFFER_SIZE ? len : NET_BUFFER_SIZE);
      rig_debug(RIG_DEBUG_WARN, "Network data cleared: %s\n", buffer);
    } else {
      break;
    }
  }
}

/**
 * \brief Open network port using rig.state data
 *
 * Open Open network port using rig.state data.
 * NB: The signal PIPE will be ignored for the whole application.
 *
 * \param rp Port data structure (must spec port id eg hostname:port)
 * \param default_port Default network socket port
 * \return RIG_OK or < 0 if error
 */
int network_open(hamlib_port_t *rp, int default_port)
{
	int fd;				/* File descriptor for the port */
	int status;
	struct addrinfo hints, *res, *saved_res;
	char *hoststr = NULL, *portstr = NULL, *bracketstr1, *bracketstr2;
	char hostname[FILPATHLEN];
	char defaultportstr[8];

#ifdef __MINGW32__
	WSADATA wsadata;
	if (!(wsstarted++) && WSAStartup(MAKEWORD(1,1), &wsadata) == SOCKET_ERROR) {
		rig_debug(RIG_DEBUG_ERR, "Error creating socket\n");
		return -RIG_EIO;
	}
#endif

	if (!rp)
		return -RIG_EINVAL;

	memset(&hints, 0, sizeof(hints));
	hints.ai_family = PF_UNSPEC;
	if (rp->type.rig == RIG_PORT_UDP_NETWORK)
		hints.ai_socktype = SOCK_DGRAM;
	else
		hints.ai_socktype = SOCK_STREAM;

	hoststr = NULL;								/* default of all local interfaces */
	if (rp->pathname[0] == ':')
		{
			portstr = rp->pathname + 1;
		}
	else
		{
			if (strlen (rp->pathname))
				{
					strncpy(hostname, rp->pathname, FILPATHLEN-1);
					hoststr = hostname;
					/* look for IPv6 numeric form [<addr>] */
					bracketstr1 = strchr(hoststr, '[');
					bracketstr2 = strrchr(hoststr, ']');
					if (bracketstr1 && bracketstr2 && bracketstr2 > bracketstr1)
						{
							hoststr = bracketstr1 + 1;
							*bracketstr2 = '\0';
							portstr = bracketstr2 + 1; /* possible port after ]: */
						}
					else
						{
							bracketstr2 = NULL;
							portstr = hoststr; /* possible port after : */
						}
					/* search last ':' */
					portstr = strrchr(portstr, ':');
					if (portstr)
						{
							*portstr++ = '\0';
						}
				}
			if (!portstr)
				{
					sprintf(defaultportstr, "%d", default_port);
					portstr = defaultportstr;
				}
		}

	status=getaddrinfo(hoststr, portstr, &hints, &res);
	if (status != 0) {
		rig_debug(RIG_DEBUG_ERR, "Cannot get host \"%s\": %s\n",
					rp->pathname, gai_strerror(errno));
		return -RIG_ECONF;
	}
	saved_res = res;

	/* we don't want a signal when connection get broken */
#ifdef SIGPIPE
	signal(SIGPIPE, SIG_IGN);
#endif

	do
		{
			fd = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
			if (fd < 0)
				{
					handle_error (RIG_DEBUG_ERR, "socket");
					freeaddrinfo (saved_res);
					return -RIG_EIO;
				}

			if ((status = connect(fd, res->ai_addr, res->ai_addrlen)) == 0)
				{
					break;
				}
			handle_error (RIG_DEBUG_WARN, "connect (trying next interface)");

#ifdef __MINGW32__
			closesocket (fd);
#else
			close (fd);
#endif
		} while ((res = res->ai_next) != NULL);

	freeaddrinfo (saved_res);

	if (NULL == res) {
		rig_debug (RIG_DEBUG_ERR, "Failed to connect to %s\n" , rp->pathname);
		return -RIG_EIO;
	}

	rp->fd = fd;
	return RIG_OK;
}

int network_close(hamlib_port_t *rp)
{
	int ret;
#ifdef __MINGW32__
	ret = closesocket(rp->fd);
	if (--wsstarted)
		WSACleanup();
#else
	ret = close(rp->fd);
#endif
	return ret;
}

/** @} */