tcp.cpp

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/*
   rdesktop: A Remote Desktop Protocol client.
   Protocol services - TCP layer
   Copyright (C) Matthew Chapman 1999-2002

   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 <unistd.h>             /* select read write close */
#include <sys/socket.h>         /* socket connect setsockopt */
#include <sys/time.h>           /* timeval */
#include <netdb.h>              /* gethostbyname */
#include <netinet/in.h>         /* sockaddr_in */
#include <netinet/tcp.h>        /* TCP_NODELAY */
#include <arpa/inet.h>          /* inet_addr */
#include <fcntl.h>
#include <errno.h>              /* errno */
#include "rdesktop.h"

#ifndef INADDR_NONE
#define INADDR_NONE ((unsigned long) -1)
#endif

static int sock;
static struct stream in;
static struct stream out;
extern int tcp_port_rdp;

/* Initialise TCP transport data packet */
STREAM
tcp_init(unsigned int maxlen)
{
        if (maxlen > out.size)
        {
                out.data = (unsigned char*)xrealloc(out.data, maxlen);
                out.size = maxlen;
        }

        out.p = out.data;
        out.end = out.data + out.size;
        return &out;
}

/* Send TCP transport data packet */
void
tcp_send(STREAM s)
{
        int length = s->end - s->data;
        int sent, total = 0;

        while (total < length)
        {
                sent = send(sock, s->data + total, length - total, 0);
                if (sent == -1 && errno == EWOULDBLOCK)
                {
                        usleep(1000);
                }
                else if (sent <= 0)
                {
                        error("send: %s\n", strerror(errno));
                        return;
                }
                else
                        total += sent;
        }
}

/* Receive a message on the TCP layer */
STREAM
tcp_recv(unsigned int length)
{
        int rcvd = 0;

        if (length > in.size)
        {
                in.data = (unsigned char*)xrealloc(in.data, length);
                in.size = length;
        }

        in.end = in.p = in.data;

        while (length > 0)
        {
                if (!ui_select(sock))
                        /* User quit */
                        return NULL;

                rcvd = recv(sock, in.end, length, 0);
                if (rcvd == -1 && errno == EWOULDBLOCK)
                {
                        usleep(1000);
                }
                else if (rcvd == -1)
                {
                        error("recv: %s\n", strerror(errno));
                        return NULL;
                }
                else if (rcvd == 0)
                        return NULL;
                else
                {
                        in.end += rcvd;
                        length -= rcvd;
                }
        }

        return &in;
}

/* Establish a connection on the TCP layer */
BOOL
tcp_connect(char *server)
{
        struct hostent *nslookup;
        struct sockaddr_in servaddr;
        int l_true = 1;

        if ((nslookup = gethostbyname(server)) != NULL)
        {
                memcpy(&servaddr.sin_addr, nslookup->h_addr, sizeof(servaddr.sin_addr));
        }
        else if ((servaddr.sin_addr.s_addr = inet_addr(server)) == INADDR_NONE)
        {
                error("%s: unable to resolve host\n", server);
                return False;
        }

        if ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0)
        {
                error("socket: %s\n", strerror(errno));
                return False;
        }

        servaddr.sin_family = AF_INET;
        servaddr.sin_port = htons(tcp_port_rdp);

        if (connect(sock, (struct sockaddr *) &servaddr, sizeof(struct sockaddr)) < 0)
        {
                error("connect: %s\n", strerror(errno));
                close(sock);
                return False;
        }

        /* set non blocking */
        {
                int op;
                op = fcntl(sock, F_GETFL);
                op |= O_NONBLOCK;
                fcntl(sock, F_SETFL, op);
        }

//      fcntl(sock, O_NONBLOCK);
        setsockopt(sock, IPPROTO_TCP, TCP_NODELAY, (void *) &l_true, sizeof(l_true));

        in.size = 4096;
        in.data = (unsigned char*)xmalloc(in.size);

        out.size = 4096;
        out.data = (unsigned char*)xmalloc(out.size);

        return True;
}

/* Disconnect on the TCP layer */
void
tcp_disconnect(void)
{
        close(sock);
}

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