AmigActive 2/AACD 2.iso/AACD/Online/Socks5/src/server/flow.c

C/C++ Source or Header | 1999-03-10 | 5.4 KB | 178 lines

/* Copyright (c) 1995-1999 NEC USA, Inc.  All rights reserved.               */
/*                                                                           */
/* The redistribution, use and modification in source or binary forms of     */
/* this software is subject to the conditions set forth in the copyright     */
/* document ("Copyright") included with this distribution.                   */

/*
 * $Id: flow.c,v 1.31.4.4 1999/02/03 22:35:34 steve Exp $
 */

/* This file has all the function to do tcp proxying itself.  The only one   */
/* that is visible to the outside world should be HandleTcpConnection.       */
#include "socks5p.h"
#include "daemon.h"
#include "proxy.h"
#include "flow.h"
#include "log.h"
#include "msg.h"

#ifndef INACTIVITY_TIMEOUT
#define INACTIVITY_TIMEOUT 15*60 /* How much inactivity will I tolerate???   */
#endif

static int proxyinturn() {
    static int turn = 0;

    return turn = turn?0:1;
}

static int FlowSetup(S5Packet *buf) {
    char *olddata = buf->data;

    if (buf->data == NULL) {
    buf->data = malloc(GENERICBUFSIZE);
    if (buf->data) S5LogUpdate(S5LogDefaultHandle, S5_LOG_DEBUG(10), 0, "Flow Setup: Allocated Buffer");
    buf->len  = GENERICBUFSIZE;
    buf->off  = 0;
    }

    if (buf->len == buf->off) {
    buf->data = realloc(olddata = buf->data, buf->len += GENERICBUFSIZE);
    if (buf->data) S5LogUpdate(S5LogDefaultHandle, S5_LOG_DEBUG(10), 0, "Flow Setup: Grew Buffer");
    }

    if (buf->data == NULL) {
    S5LogUpdate(S5LogDefaultHandle, S5_LOG_WARNING, 0, "Flow Setup: Couldn't allocate buffer space");
    if (!olddata) free(olddata);
    return -1;
    }

    return 0;
}

int S5TcpFlowRecv(S5IOInfo *iio, S5IOInfo *oio, S5Packet *packet, int *dir) {
    S5IOHandle fdsbits = ((iio->fd > oio->fd)?iio->fd:oio->fd)+1;
    fd_set fds, xfds, bu;
    S5IOInfo *io;
    char *string;
    int n;
    int turn = 1;

    FD_ZERO(&bu);
    if (*dir & S5_DIRECTION_OUT) FD_SET(iio->fd, &bu);
    if (*dir & S5_DIRECTION_IN)  FD_SET(oio->fd, &bu);

    if (FlowSetup(packet) < 0) {
    return -1;
    }

    for (fds = bu ; ; fds = bu) {
    struct timeval tout;

    tout.tv_sec = idletimeout*60;
    tout.tv_usec = 0;
    if (!FD_ISSET(iio->fd,  &fds) && !FD_ISSET(oio->fd, &fds)) {
        S5LogUpdate(S5LogDefaultHandle, S5_LOG_WARNING, 0, "Flow Recv: Neither file descriptor is set");
        return -1;
    }

        xfds = fds;
    switch (select(fdsbits, &fds, NULL, &xfds, &tout)) {
        case -1:
        if (ISSOCKETERROR(EINTR)) continue;
        S5LogUpdate(S5LogDefaultHandle, S5_LOG_WARNING, 0, "Flow Recv: Select failed: %m");
        return -1;
        case 0:
        S5LogUpdate(S5LogDefaultHandle, S5_LOG_WARNING, 0, "Flow Recv: Select failed: Inactivity timeout");
        return -1;
    }

    if (FD_ISSET(iio->fd, &xfds) && FD_ISSET(oio->fd, &xfds))
            turn = proxyinturn();
        else if (FD_ISSET(iio->fd, &xfds))
            turn = 1;
        else if (FD_ISSET(oio->fd, &xfds))
            turn = 0;
        else if (FD_ISSET(iio->fd, &fds) && FD_ISSET(oio->fd, &fds))
            turn = proxyinturn();
        else if (FD_ISSET(iio->fd, &fds))
            turn = 1;
    else if (FD_ISSET(oio->fd, &fds))
            turn = 0;
    else {
        S5LogUpdate(S5LogDefaultHandle, S5_LOG_WARNING, 0, "Flow Recv: Invalid file descriptor set");
        return -1;
    }

        if (turn) {
            *dir = S5_DIRECTION_OUT;
            string = "client";
            io = iio;
        } else {
            *dir = S5_DIRECTION_IN;
            string = "server";
            io = oio;
        }

        packet->oob = 0;
        if (FD_ISSET(io->fd, &xfds))
            (void) ioctl(io->fd, SIOCATMARK, (char *)&packet->oob);

#define RECV_IOFLAGS S5_IOFLAGS_TIMED|S5_IOFLAGS_RESTART

    S5LogUpdate(S5LogDefaultHandle, S5_LOG_DEBUG(10), 0, "Flow Recv: Reading from %s socket", string);
    switch ((n = S5BufReadPacket(io->fd, io, packet->data + packet->off, packet->oob?1:packet->len - packet->off, 0))) {
        case -1:
        S5LogUpdate(S5LogDefaultHandle, S5_LOG_WARNING,  0, "Flow Recv: %s Read failed: %m", string);
        return -1;
        case 0:
        S5LogUpdate(S5LogDefaultHandle, S5_LOG_DEBUG(0), 0, "Flow Recv: %s closed connection", string);
        return 0;
        default:
        S5LogUpdate(S5LogDefaultHandle, S5_LOG_DEBUG(10), 0, "Flow Recv: Read %d bytes from %s socket", n, string);
        packet->off += n;
        return n;
    }
    }
}

int S5TcpFlowSend(S5IOInfo *iio, S5IOInfo *oio, S5Packet *packet, int *dir) {
    double timerm = (double)idletimeout*60;
    S5IOInfo *io;
    char *string;
    int n;

    switch (*dir) {
    case S5_DIRECTION_OUT:
        string = "server";
        io = oio;
        break;
    case S5_DIRECTION_IN:
        string = "client";
        io = iio;
        break;
    default:
        S5LogUpdate(S5LogDefaultHandle, S5_LOG_WARNING, 0, "Flow Send: Invalid direction: %d", *dir);
        return -1;
    }

    S5LogUpdate(S5LogDefaultHandle, S5_LOG_DEBUG(10), 0, "Flow Send: Writing %d bytes to %s socket", packet->off, string);

#define SEND_IOFLAGS S5_IOFLAGS_TIMED|S5_IOFLAGS_RESTART|S5_IOFLAGS_NBYTES

    switch ((n = S5IOSend(io->fd, io, packet->data, packet->off, packet->oob?MSG_OOB:0, SEND_IOFLAGS, &timerm))) {
    case -1:
        S5LogUpdate(S5LogDefaultHandle, S5_LOG_WARNING, 0, "Flow Send: %s Write failed: %m", string);
        return -1;
    case 0:
        S5LogUpdate(S5LogDefaultHandle, S5_LOG_DEBUG(0), 0, "Flow Send: %s closed connection", string);
        return 0;
    default:
        S5LogUpdate(S5LogDefaultHandle, S5_LOG_DEBUG(10), 0, "Flow Send: Wrote %d bytes to %s", n, string);
        packet->off -= n;
        return n;
    }
}