winnet.c

远程登陆工具软件源码 用于远程登陆unix

    ret->address = p_ntohl(a);
    realhost[lenof(realhost)-1] = '\0';
    *canonicalname = snewn(1+strlen(realhost), char);
    strcpy(*canonicalname, realhost);
    return ret;
}

SockAddr sk_nonamelookup(const char *host)
{
    SockAddr ret = snew(struct SockAddr_tag);
    ret->error = NULL;
    ret->family = AF_UNSPEC;
    strncpy(ret->hostname, host, lenof(ret->hostname));
    ret->hostname[lenof(ret->hostname)-1] = '\0';
    return ret;
}

void sk_getaddr(SockAddr addr, char *buf, int buflen)
{
#ifdef IPV6
    if (addr->family == AF_INET6) {
	FIXME; /* I don't know how to get a text form of an IPv6 address. */
    } else
#endif
    if (addr->family == AF_INET) {
	struct in_addr a;
	a.s_addr = p_htonl(addr->address);
	strncpy(buf, p_inet_ntoa(a), buflen);
	buf[buflen-1] = '\0';
    } else {
	assert(addr->family == AF_UNSPEC);
	strncpy(buf, addr->hostname, buflen);
	buf[buflen-1] = '\0';
    }
}

int sk_hostname_is_local(char *name)
{
    return !strcmp(name, "localhost");
}

static INTERFACE_INFO local_interfaces[16];
static int n_local_interfaces;       /* 0=not yet, -1=failed, >0=number */

static int ipv4_is_local_addr(struct in_addr addr)
{
    if (ipv4_is_loopback(addr))
	return 1;		       /* loopback addresses are local */
    if (!n_local_interfaces) {
	SOCKET s = p_socket(AF_INET, SOCK_DGRAM, 0);
	DWORD retbytes;

	if (p_WSAIoctl &&
	    p_WSAIoctl(s, SIO_GET_INTERFACE_LIST, NULL, 0,
		       local_interfaces, sizeof(local_interfaces),
		       &retbytes, NULL, NULL) == 0)
	    n_local_interfaces = retbytes / sizeof(INTERFACE_INFO);
	else
	    logevent(NULL, "Unable to get list of local IP addresses");
    }
    if (n_local_interfaces > 0) {
	int i;
	for (i = 0; i < n_local_interfaces; i++) {
	    SOCKADDR_IN *address =
		(SOCKADDR_IN *)&local_interfaces[i].iiAddress;
	    if (address->sin_addr.s_addr == addr.s_addr)
		return 1;	       /* this address is local */
	}
    }
    return 0;		       /* this address is not local */
}

int sk_address_is_local(SockAddr addr)
{
#ifdef IPV6
    if (addr->family == AF_INET6) {
	FIXME;  /* someone who can compile for IPV6 had better do this bit */
    } else
#endif
    if (addr->family == AF_INET) {
	struct in_addr a;
	a.s_addr = p_htonl(addr->address);
	return ipv4_is_local_addr(a);
    } else {
	assert(addr->family == AF_UNSPEC);
	return 0;		       /* we don't know; assume not */
    }
}

int sk_addrtype(SockAddr addr)
{
    return (addr->family == AF_INET ? ADDRTYPE_IPV4 :
#ifdef IPV6
	    addr->family == AF_INET6 ? ADDRTYPE_IPV6 :
#endif
	    ADDRTYPE_NAME);
}

void sk_addrcopy(SockAddr addr, char *buf)
{
    assert(addr->family != AF_UNSPEC);
#ifdef IPV6
    if (addr->family == AF_INET6) {
	memcpy(buf, (char*) addr->ai, 16);
    } else
#endif
    if (addr->family == AF_INET) {
	struct in_addr a;
	a.s_addr = p_htonl(addr->address);
	memcpy(buf, (char*) &a.s_addr, 4);
    }
}

void sk_addr_free(SockAddr addr)
{
    sfree(addr);
}

static Plug sk_tcp_plug(Socket sock, Plug p)
{
    Actual_Socket s = (Actual_Socket) sock;
    Plug ret = s->plug;
    if (p)
	s->plug = p;
    return ret;
}

static void sk_tcp_flush(Socket s)
{
    /*
     * We send data to the socket as soon as we can anyway,
     * so we don't need to do anything here.  :-)
     */
}

static void sk_tcp_close(Socket s);
static int sk_tcp_write(Socket s, const char *data, int len);
static int sk_tcp_write_oob(Socket s, const char *data, int len);
static void sk_tcp_set_private_ptr(Socket s, void *ptr);
static void *sk_tcp_get_private_ptr(Socket s);
static void sk_tcp_set_frozen(Socket s, int is_frozen);
static const char *sk_tcp_socket_error(Socket s);

extern char *do_select(SOCKET skt, int startup);

Socket sk_register(void *sock, Plug plug)
{
    static const struct socket_function_table fn_table = {
	sk_tcp_plug,
	sk_tcp_close,
	sk_tcp_write,
	sk_tcp_write_oob,
	sk_tcp_flush,
	sk_tcp_set_private_ptr,
	sk_tcp_get_private_ptr,
	sk_tcp_set_frozen,
	sk_tcp_socket_error
    };

    DWORD err;
    char *errstr;
    Actual_Socket ret;

    /*
     * Create Socket structure.
     */
    ret = snew(struct Socket_tag);
    ret->fn = &fn_table;
    ret->error = NULL;
    ret->plug = plug;
    bufchain_init(&ret->output_data);
    ret->writable = 1;		       /* to start with */
    ret->sending_oob = 0;
    ret->frozen = 1;
    ret->frozen_readable = 0;
    ret->localhost_only = 0;	       /* unused, but best init anyway */
    ret->pending_error = 0;

    ret->s = (SOCKET)sock;

    if (ret->s == INVALID_SOCKET) {
	err = p_WSAGetLastError();
	ret->error = winsock_error_string(err);
	return (Socket) ret;
    }

    ret->oobinline = 0;

    /* Set up a select mechanism. This could be an AsyncSelect on a
     * window, or an EventSelect on an event object. */
    errstr = do_select(ret->s, 1);
    if (errstr) {
	ret->error = errstr;
	return (Socket) ret;
    }

    add234(sktree, ret);

    return (Socket) ret;
}

Socket sk_new(SockAddr addr, int port, int privport, int oobinline,
	      int nodelay, int keepalive, Plug plug)
{
    static const struct socket_function_table fn_table = {
	sk_tcp_plug,
	sk_tcp_close,
	sk_tcp_write,
	sk_tcp_write_oob,
	sk_tcp_flush,
	sk_tcp_set_private_ptr,
	sk_tcp_get_private_ptr,
	sk_tcp_set_frozen,
	sk_tcp_socket_error
    };

    SOCKET s;
#ifdef IPV6
    SOCKADDR_IN6 a6;
#endif
    SOCKADDR_IN a;
    DWORD err;
    char *errstr;
    Actual_Socket ret;
    short localport;

    /*
     * Create Socket structure.
     */
    ret = snew(struct Socket_tag);
    ret->fn = &fn_table;
    ret->error = NULL;
    ret->plug = plug;
    bufchain_init(&ret->output_data);
    ret->connected = 0;		       /* to start with */
    ret->writable = 0;		       /* to start with */
    ret->sending_oob = 0;
    ret->frozen = 0;
    ret->frozen_readable = 0;
    ret->localhost_only = 0;	       /* unused, but best init anyway */
    ret->pending_error = 0;

    /*
     * Open socket.
     */
    assert(addr->family != AF_UNSPEC);
    s = p_socket(addr->family, SOCK_STREAM, 0);
    ret->s = s;

    if (s == INVALID_SOCKET) {
	err = p_WSAGetLastError();
	ret->error = winsock_error_string(err);
	return (Socket) ret;
    }

    ret->oobinline = oobinline;
    if (oobinline) {
	BOOL b = TRUE;
	p_setsockopt(s, SOL_SOCKET, SO_OOBINLINE, (void *) &b, sizeof(b));
    }

    if (nodelay) {
	BOOL b = TRUE;
	p_setsockopt(s, IPPROTO_TCP, TCP_NODELAY, (void *) &b, sizeof(b));
    }

    if (keepalive) {
	BOOL b = TRUE;
	p_setsockopt(s, SOL_SOCKET, SO_KEEPALIVE, (void *) &b, sizeof(b));
    }

    /*
     * Bind to local address.
     */
    if (privport)
	localport = 1023;	       /* count from 1023 downwards */
    else
	localport = 0;		       /* just use port 0 (ie winsock picks) */

    /* Loop round trying to bind */
    while (1) {
	int retcode;

#ifdef IPV6
	if (addr->family == AF_INET6) {
	    memset(&a6, 0, sizeof(a6));
	    a6.sin6_family = AF_INET6;
/*a6.sin6_addr      = in6addr_any; *//* == 0 */
	    a6.sin6_port = p_htons(localport);
	} else
#endif
	{
	    a.sin_family = AF_INET;
	    a.sin_addr.s_addr = p_htonl(INADDR_ANY);
	    a.sin_port = p_htons(localport);
	}
#ifdef IPV6
	retcode = p_bind(s, (addr->family == AF_INET6 ?
			   (struct sockaddr *) &a6 :
			   (struct sockaddr *) &a),
		       (addr->family ==
			AF_INET6 ? sizeof(a6) : sizeof(a)));
#else
	retcode = p_bind(s, (struct sockaddr *) &a, sizeof(a));
#endif
	if (retcode != SOCKET_ERROR) {
	    err = 0;
	    break;		       /* done */
	} else {
	    err = p_WSAGetLastError();
	    if (err != WSAEADDRINUSE)  /* failed, for a bad reason */
		break;
	}

	if (localport == 0)
	    break;		       /* we're only looping once */
	localport--;
	if (localport == 0)
	    break;		       /* we might have got to the end */
    }

    if (err) {
	ret->error = winsock_error_string(err);
	return (Socket) ret;
    }

    /*
     * Connect to remote address.
     */
#ifdef IPV6
    if (addr->family == AF_INET6) {
	memset(&a, 0, sizeof(a));
	a6.sin6_family = AF_INET6;
	a6.sin6_port = p_htons((short) port);
	a6.sin6_addr =
	    ((struct sockaddr_in6 *) addr->ai->ai_addr)->sin6_addr;
    } else
#endif
    {
	a.sin_family = AF_INET;
	a.sin_addr.s_addr = p_htonl(addr->address);
	a.sin_port = p_htons((short) port);
    }

    /* Set up a select mechanism. This could be an AsyncSelect on a
     * window, or an EventSelect on an event object. */
    errstr = do_select(s, 1);
    if (errstr) {
	ret->error = errstr;
	return (Socket) ret;
    }

    if ((
#ifdef IPV6
	    p_connect(s, ((addr->family == AF_INET6) ?
			(struct sockaddr *) &a6 : (struct sockaddr *) &a),
		    (addr->family == AF_INET6) ? sizeof(a6) : sizeof(a))
#else
	    p_connect(s, (struct sockaddr *) &a, sizeof(a))
#endif
	) == SOCKET_ERROR) {
	err = p_WSAGetLastError();
	/*
	 * We expect a potential EWOULDBLOCK here, because the
	 * chances are the front end has done a select for
	 * FD_CONNECT, so that connect() will complete
	 * asynchronously.
	 */
	if ( err != WSAEWOULDBLOCK ) {
	    ret->error = winsock_error_string(err);
	    return (Socket) ret;
	}
    } else {
	/*
	 * If we _don't_ get EWOULDBLOCK, the connect has completed
	 * and we should set the socket as writable.
	 */
	ret->writable = 1;
    }

    add234(sktree, ret);

    /* We're done with 'addr' now. */
    sk_addr_free(addr);

    return (Socket) ret;
}

Socket sk_newlistener(char *srcaddr, int port, Plug plug, int local_host_only)
{
    static const struct socket_function_table fn_table = {
	sk_tcp_plug,
	sk_tcp_close,
	sk_tcp_write,
	sk_tcp_write_oob,
	sk_tcp_flush,
	sk_tcp_set_private_ptr,
	sk_tcp_get_private_ptr,
	sk_tcp_set_frozen,
	sk_tcp_socket_error
    };

    SOCKET s;
#ifdef IPV6
    SOCKADDR_IN6 a6;
#endif
    SOCKADDR_IN a;
    DWORD err;
    char *errstr;
    Actual_Socket ret;
    int retcode;
    int on = 1;

    /*
     * Create Socket structure.
     */
    ret = snew(struct Socket_tag);
    ret->fn = &fn_table;
    ret->error = NULL;
    ret->plug = plug;
    bufchain_init(&ret->output_data);
    ret->writable = 0;		       /* to start with */
    ret->sending_oob = 0;
    ret->frozen = 0;
    ret->frozen_readable = 0;
    ret->localhost_only = local_host_only;
    ret->pending_error = 0;

    /*
     * Open socket.
     */
    s = p_socket(AF_INET, SOCK_STREAM, 0);
    ret->s = s;

    if (s == INVALID_SOCKET) {
	err = p_WSAGetLastError();
	ret->error = winsock_error_string(err);
	return (Socket) ret;
    }

    ret->oobinline = 0;

    p_setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (const char *)&on, sizeof(on));

#ifdef IPV6
	if (addr->family == AF_INET6) {
	    memset(&a6, 0, sizeof(a6));
	    a6.sin6_family = AF_INET6;
	    /* FIXME: srcaddr is ignored for IPv6, because I (SGT) don't
	     * know how to do it. :-) */
	    if (local_host_only)
		a6.sin6_addr = in6addr_loopback;
	    else
		a6.sin6_addr = in6addr_any;
	    a6.sin6_port = p_htons(port);
	} else
#endif
	{