source: vbox/trunk/src/VBox/RDP/client/tcp.c@ 44821

/* -*- c-basic-offset: 8 -*-
   rdesktop: A Remote Desktop Protocol client.
   Protocol services - TCP layer
   Copyright (C) Matthew Chapman <matthewc.unsw.edu.au> 1999-2008
   Copyright 2005-2011 Peter Astrand <astrand@cendio.se> for Cendio AB

   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 3 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, see <http://www.gnu.org/licenses/>.
*/

/*
 * Oracle GPL Disclaimer: For the avoidance of doubt, except that if any license choice
 * other than GPL or LGPL is available it will apply instead, Oracle elects to use only
 * the General Public License version 2 (GPLv2) at this time for any software where
 * a choice of GPL license versions is made available with the language indicating
 * that GPLv2 or any later version may be used, or where a choice of which version
 * of the GPL is applied is otherwise unspecified.
 */

#ifndef _WIN32
#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 <errno.h>              /* errno */
#endif

#include "rdesktop.h"

#ifdef _WIN32
#define socklen_t int
#define TCP_CLOSE(_sck) closesocket(_sck)
#define TCP_STRERROR "tcp error"
#define TCP_BLOCKS (WSAGetLastError() == WSAEWOULDBLOCK)
#else
#define TCP_CLOSE(_sck) close(_sck)
#define TCP_STRERROR strerror(errno)
#define TCP_BLOCKS (errno == EWOULDBLOCK)
#endif

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

#ifdef WITH_SCARD
#define STREAM_COUNT 8
#else
#define STREAM_COUNT 1
#endif

static int g_sock;
static struct stream g_in;
static struct stream g_out[STREAM_COUNT];
int g_tcp_port_rdp = TCP_PORT_RDP;
extern RD_BOOL g_user_quit;

/* wait till socket is ready to write or timeout */
static RD_BOOL
tcp_can_send(int sck, int millis)
{
        fd_set wfds;
        struct timeval time;
        int sel_count;

        time.tv_sec = millis / 1000;
        time.tv_usec = (millis * 1000) % 1000000;
        FD_ZERO(&wfds);
        FD_SET(sck, &wfds);
        sel_count = select(sck + 1, 0, &wfds, 0, &time);
        if (sel_count > 0)
        {
                return True;
        }
        return False;
}

/* Initialise TCP transport data packet */
STREAM
tcp_init(uint32 maxlen)
{
        static int cur_stream_id = 0;
        STREAM result = NULL;

#ifdef WITH_SCARD
        scard_lock(SCARD_LOCK_TCP);
#endif
        result = &g_out[cur_stream_id];
        cur_stream_id = (cur_stream_id + 1) % STREAM_COUNT;

        if (maxlen > result->size)
        {
                result->data = (uint8 *) xrealloc(result->data, maxlen);
                result->size = maxlen;
        }

        result->p = result->data;
        result->end = result->data + result->size;
#ifdef WITH_SCARD
        scard_unlock(SCARD_LOCK_TCP);
#endif
        return result;
}

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

#ifdef WITH_SCARD
        scard_lock(SCARD_LOCK_TCP);
#endif
        while (total < length)
        {
                sent = send(g_sock, s->data + total, length - total, 0);
                if (sent <= 0)
                {
                        if (sent == -1 && TCP_BLOCKS)
                        {
                                tcp_can_send(g_sock, 100);
                                sent = 0;
                        }
                        else
                        {
                                error("send: %s\n", TCP_STRERROR);
                                return;
                        }
                }
                total += sent;
        }
#ifdef WITH_SCARD
        scard_unlock(SCARD_LOCK_TCP);
#endif
}

/* Receive a message on the TCP layer */
STREAM
tcp_recv(STREAM s, uint32 length)
{
        uint32 new_length, end_offset, p_offset;
        int rcvd = 0;

        if (s == NULL)
        {
                /* read into "new" stream */
                if (length > g_in.size)
                {
                        g_in.data = (uint8 *) xrealloc(g_in.data, length);
                        g_in.size = length;
                }
                g_in.end = g_in.p = g_in.data;
                s = &g_in;
        }
        else
        {
                /* append to existing stream */
                new_length = (s->end - s->data) + length;
                if (new_length > s->size)
                {
                        p_offset = s->p - s->data;
                        end_offset = s->end - s->data;
                        s->data = (uint8 *) xrealloc(s->data, new_length);
                        s->size = new_length;
                        s->p = s->data + p_offset;
                        s->end = s->data + end_offset;
                }
        }

        while (length > 0)
        {
                if (!ui_select(g_sock))
                {
                        /* User quit */
                        g_user_quit = True;
                        return NULL;
                }

                rcvd = recv(g_sock, s->end, length, 0);
                if (rcvd < 0)
                {
                        if (rcvd == -1 && TCP_BLOCKS)
                        {
                                rcvd = 0;
                        }
                        else
                        {
                                error("recv: %s\n", TCP_STRERROR);
                                return NULL;
                        }
                }
                else if (rcvd == 0)
                {
                        error("Connection closed\n");
                        return NULL;
                }

                s->end += rcvd;
                length -= rcvd;
        }

        return s;
}

/* Establish a connection on the TCP layer */
RD_BOOL
tcp_connect(char *server)
{
        socklen_t option_len;
        uint32 option_value;
        int i;

#ifdef IPv6

        int n;
        struct addrinfo hints, *res, *ressave;
        char tcp_port_rdp_s[10];

        snprintf(tcp_port_rdp_s, 10, "%d", g_tcp_port_rdp);

        memset(&hints, 0, sizeof(struct addrinfo));
        hints.ai_family = AF_UNSPEC;
        hints.ai_socktype = SOCK_STREAM;

        if ((n = getaddrinfo(server, tcp_port_rdp_s, &hints, &res)))
        {
                error("getaddrinfo: %s\n", gai_strerror(n));
                return False;
        }

        ressave = res;
        g_sock = -1;
        while (res)
        {
                g_sock = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
                if (!(g_sock < 0))
                {
                        if (connect(g_sock, res->ai_addr, res->ai_addrlen) == 0)
                                break;
                        TCP_CLOSE(g_sock);
                        g_sock = -1;
                }
                res = res->ai_next;
        }
        freeaddrinfo(ressave);

        if (g_sock == -1)
        {
                error("%s: unable to connect\n", server);
                return False;
        }

#else /* no IPv6 support */

        struct hostent *nslookup;
        struct sockaddr_in servaddr;

        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 ((g_sock = socket(AF_INET, SOCK_STREAM, 0)) < 0)
        {
                error("socket: %s\n", TCP_STRERROR);
                return False;
        }

        servaddr.sin_family = AF_INET;
        servaddr.sin_port = htons((uint16) g_tcp_port_rdp);

        if (connect(g_sock, (struct sockaddr *) &servaddr, sizeof(struct sockaddr)) < 0)
        {
                error("connect: %s\n", TCP_STRERROR);
                TCP_CLOSE(g_sock);
                return False;
        }

#endif /* IPv6 */

        option_value = 1;
        option_len = sizeof(option_value);
        setsockopt(g_sock, IPPROTO_TCP, TCP_NODELAY, (void *) &option_value, option_len);
        /* receive buffer must be a least 16 K */
        if (getsockopt(g_sock, SOL_SOCKET, SO_RCVBUF, (void *) &option_value, &option_len) == 0)
        {
                if (option_value < (1024 * 16))
                {
                        option_value = 1024 * 16;
                        option_len = sizeof(option_value);
                        setsockopt(g_sock, SOL_SOCKET, SO_RCVBUF, (void *) &option_value,
                                   option_len);
                }
        }

        g_in.size = 4096;
        g_in.data = (uint8 *) xmalloc(g_in.size);

        for (i = 0; i < STREAM_COUNT; i++)
        {
                g_out[i].size = 4096;
                g_out[i].data = (uint8 *) xmalloc(g_out[i].size);
        }

        return True;
}

/* Disconnect on the TCP layer */
void
tcp_disconnect(void)
{
        TCP_CLOSE(g_sock);
}

char *
tcp_get_address()
{
        static char ipaddr[32];
        struct sockaddr_in sockaddr;
        socklen_t len = sizeof(sockaddr);
        if (getsockname(g_sock, (struct sockaddr *) &sockaddr, &len) == 0)
        {
                uint8 *ip = (uint8 *) & sockaddr.sin_addr;
                sprintf(ipaddr, "%d.%d.%d.%d", ip[0], ip[1], ip[2], ip[3]);
        }
        else
                strcpy(ipaddr, "127.0.0.1");
        return ipaddr;
}

/* reset the state of the tcp layer */
/* Support for Session Directory */
void
tcp_reset_state(void)
{
        int i;

        g_sock = -1;            /* reset socket */

        /* Clear the incoming stream */
        if (g_in.data != NULL)
                xfree(g_in.data);
        g_in.p = NULL;
        g_in.end = NULL;
        g_in.data = NULL;
        g_in.size = 0;
        g_in.iso_hdr = NULL;
        g_in.mcs_hdr = NULL;
        g_in.sec_hdr = NULL;
        g_in.rdp_hdr = NULL;
        g_in.channel_hdr = NULL;

        /* Clear the outgoing stream(s) */
        for (i = 0; i < STREAM_COUNT; i++)
        {
                if (g_out[i].data != NULL)
                        xfree(g_out[i].data);
                g_out[i].p = NULL;
                g_out[i].end = NULL;
                g_out[i].data = NULL;
                g_out[i].size = 0;
                g_out[i].iso_hdr = NULL;
                g_out[i].mcs_hdr = NULL;
                g_out[i].sec_hdr = NULL;
                g_out[i].rdp_hdr = NULL;
                g_out[i].channel_hdr = NULL;
        }
}