newlib/winsup/cygserver/client.cc

527 lines
12 KiB
C++

/* client.cc
Copyright 2001, 2002, 2003, 2004, 2008, 2009, 2012, 2013, 2014 Red Hat Inc.
Written by Egor Duda <deo@logos-m.ru>
This file is part of Cygwin.
This software is a copyrighted work licensed under the terms of the
Cygwin license. Please consult the file "CYGWIN_LICENSE" for
details. */
/* to allow this to link into cygwin and the .dll, a little magic is needed. */
#ifdef __OUTSIDE_CYGWIN__
#include "woutsup.h"
#else
#include "winsup.h"
#endif
#include <assert.h>
#include <errno.h>
#include <stdio.h>
#include <unistd.h>
#include "cygserver_msg.h"
#include "cygserver_sem.h"
#include "cygserver_shm.h"
#include "cygserver_setpwd.h"
#include "cygserver_pwdgrp.h"
#include "cygserver.h"
#include "transport.h"
int cygserver_running = CYGSERVER_UNKNOWN; // Nb: inherited by children.
client_request_get_version::client_request_get_version ()
: client_request (CYGSERVER_REQUEST_GET_VERSION, &version, sizeof (version))
{
msglen (0); // No parameters for request.
// verbose: syscall_printf ("created");
}
/*
* client_request_get_version::check_version ()
*
* The major version and API version numbers must match exactly. An
* older than expected minor version number is accepted (as long as
* the first numbers match, that is).
*/
#ifdef __INSIDE_CYGWIN__
bool
client_request_get_version::check_version () const
{
const bool ok = (version.major == CYGWIN_SERVER_VERSION_MAJOR
&& version.api == CYGWIN_SERVER_VERSION_API
&& version.minor <= CYGWIN_SERVER_VERSION_MINOR);
if (!ok)
syscall_printf (("incompatible version of cygwin server: "
"client version %d.%d.%d.%d, "
"server version %d.%d.%d.%d"),
CYGWIN_SERVER_VERSION_MAJOR,
CYGWIN_SERVER_VERSION_API,
CYGWIN_SERVER_VERSION_MINOR,
CYGWIN_SERVER_VERSION_PATCH,
version.major,
version.api,
version.minor,
version.patch);
return ok;
}
client_request_attach_tty::client_request_attach_tty (DWORD nmaster_pid,
HANDLE nfrom_master,
HANDLE nto_master)
: client_request (CYGSERVER_REQUEST_ATTACH_TTY, &req, sizeof (req))
{
req.pid = GetCurrentProcessId ();
req.master_pid = nmaster_pid;
req.from_master = nfrom_master;
req.to_master = nto_master;
syscall_printf (("created: pid = %u, master_pid = %u, "
"from_master = %p, to_master = %p"),
req.pid, req.master_pid, req.from_master, req.to_master);
}
#endif /* __INSIDE_CYGWIN__ */
/*
* client_request_attach_tty::send ()
*
* Wraps the base method to provide error handling support. If the
* reply contains a body but is flagged as an error, close any handles
* that have been returned by cygserver and then discard the message
* body, i.e. the client either sees a successful result with handles
* or an unsuccessful result with no handles.
*/
void
client_request_attach_tty::send (transport_layer_base * const conn)
{
client_request::send (conn);
if (msglen () && error_code ())
{
if (from_master ())
CloseHandle (from_master ());
if (to_master ())
CloseHandle (to_master ());
msglen (0);
}
}
client_request::header_t::header_t (const request_code_t request_code,
const size_t len)
: request_code (request_code)
{
assert (request_code >= 0 && request_code < CYGSERVER_REQUEST_LAST);
msglen = len;
}
// FIXME: also check write and read result for -1.
void
client_request::send (transport_layer_base * const conn)
{
assert (conn);
assert (!(msglen () && !_buf)); // i.e., msglen () implies _buf
assert (msglen () <= _buflen);
{
const ssize_t count = conn->write (&_header, sizeof (_header));
if (count != sizeof (_header))
{
assert (errno);
error_code (errno);
syscall_printf (("request header write failure: "
"only %ld bytes sent of %lu, "
"error = %d(%u)"),
count, sizeof (_header),
errno, GetLastError ());
return;
}
}
if (msglen ())
{
const ssize_t count = conn->write (_buf, msglen ());
if (count == -1 || (size_t) count != msglen ())
{
assert (errno);
error_code (errno);
syscall_printf (("request body write failure: "
"only %ld bytes sent of %lu, "
"error = %d(%u)"),
count, msglen (),
errno, GetLastError ());
return;
}
}
{
const ssize_t count = conn->read (&_header, sizeof (_header));
if (count != sizeof (_header))
{
assert (errno);
error_code (errno);
syscall_printf (("reply header read failure: "
"only %ld bytes received of %lu, "
"error = %d(%u)"),
count, sizeof (_header),
errno, GetLastError ());
return;
}
}
if (msglen () && !_buf)
{
system_printf ("no client buffer for reply body: %lu bytes needed",
msglen ());
error_code (EINVAL);
return;
}
if (msglen () > _buflen)
{
system_printf (("client buffer too small for reply body: "
"have %lu bytes and need %lu"),
_buflen, msglen ());
error_code (EINVAL);
return;
}
if (msglen ())
{
const ssize_t count = conn->read (_buf, msglen ());
if (count == -1 || (size_t) count != msglen ())
{
assert (errno);
error_code (errno);
syscall_printf (("reply body read failure: "
"only %ld bytes received of %lu, "
"error = %d(%u)"),
count, msglen (),
errno, GetLastError ());
return;
}
}
}
#ifdef __OUTSIDE_CYGWIN__
client_request_attach_tty::client_request_attach_tty ()
: client_request (CYGSERVER_REQUEST_ATTACH_TTY, &req, sizeof (req))
{
}
/*
* client_request::handle_request ()
*
* A server-side method.
*
* This is a factory method for the client_request subclasses. It
* reads the incoming request header and, based on its request code,
* creates an instance of the appropriate class.
*
* FIXME: If the incoming packet is malformed, the server drops it on
* the floor. Should it try and generate some sort of reply for the
* client? As it is, the client will simply get a broken connection.
*
* FIXME: also check write and read result for -1.
*/
/* static */ void
client_request::handle_request (transport_layer_base *const conn,
process_cache *const cache)
{
// verbose: debug_printf ("about to read");
header_t header;
{
const ssize_t count = conn->read (&header, sizeof (header));
if (count != sizeof (header))
{
syscall_printf (("request header read failure: "
"only %ld bytes received of %lu, "
"error = %d(%u)"),
count, sizeof (header),
errno, GetLastError ());
return;
}
}
client_request *req = NULL;
switch (header.request_code)
{
case CYGSERVER_REQUEST_GET_VERSION:
req = new client_request_get_version;
break;
case CYGSERVER_REQUEST_SHUTDOWN:
req = new client_request_shutdown;
break;
case CYGSERVER_REQUEST_ATTACH_TTY:
req = new client_request_attach_tty;
break;
case CYGSERVER_REQUEST_MSG:
req = new client_request_msg;
break;
case CYGSERVER_REQUEST_SEM:
req = new client_request_sem;
break;
case CYGSERVER_REQUEST_SHM:
req = new client_request_shm;
break;
case CYGSERVER_REQUEST_SETPWD:
req = new client_request_setpwd;
break;
case CYGSERVER_REQUEST_PWDGRP:
req = new client_request_pwdgrp;
break;
default:
syscall_printf ("unknown request code %d received: request ignored",
header.request_code);
return;
}
assert (req);
req->msglen (header.msglen);
req->handle (conn, cache);
delete req;
}
/*
* client_request::handle ()
*
* A server-side method.
*
* At this point, the header of an incoming request has been read and
* an appropriate client_request object constructed. This method has
* to read the request body into its buffer, if there is such a body,
* then perform the request and send back the results to the client.
*
* FIXME: If the incoming packet is malformed, the server drops it on
* the floor. Should it try and generate some sort of reply for the
* client? As it is, the client will simply get a broken connection.
*
* FIXME: also check write and read result for -1.
*/
void
client_request::handle (transport_layer_base *const conn,
process_cache *const cache)
{
if (msglen () && !_buf)
{
system_printf ("no buffer for request body: %lu bytes needed",
msglen ());
error_code (EINVAL);
return;
}
if (msglen () > _buflen)
{
system_printf (("buffer too small for request body: "
"have %lu bytes and need %lu"),
_buflen, msglen ());
error_code (EINVAL);
return;
}
if (msglen ())
{
const ssize_t count = conn->read (_buf, msglen ());
if (count == -1 || (size_t) count != msglen ())
{
assert (errno);
error_code (errno);
syscall_printf (("request body read failure: "
"only %ld bytes received of %lu, "
"error = %d(%u)"),
count, msglen (),
errno, GetLastError ());
return;
}
}
error_code (0); // Overwrites the _header.request_code field.
/*
* This is not allowed to fail. We must return ENOSYS at a minimum
* to the client.
*/
serve (conn, cache);
{
const ssize_t count = conn->write (&_header, sizeof (_header));
if (count != sizeof (_header))
{
assert (errno);
error_code (errno);
syscall_printf (("reply header write failure: "
"only %ld bytes sent of %lu, "
"error = %d(%u)"),
count, sizeof (_header),
errno, GetLastError ());
return;
}
}
if (msglen ())
{
const ssize_t count = conn->write (_buf, msglen ());
if (count == -1 || (size_t) count != msglen ())
{
assert (errno);
error_code (errno);
syscall_printf (("reply body write failure: "
"only %ld bytes sent of %lu, "
"error = %d(%u)"),
count, msglen (),
errno, GetLastError ());
return;
}
}
}
/* The server side implementation of make_request. Very simple. */
int
client_request::make_request ()
{
transport_layer_base *const transport = create_server_transport ();
assert (transport);
if (transport->connect () == -1)
{
if (errno)
error_code (errno);
else
error_code (ENOSYS);
delete transport;
return -1;
}
send (transport);
delete transport;
return 0;
}
#endif /* __OUTSIDE_CYGWIN__ */
client_request::client_request (request_code_t const id,
void * const buf,
size_t const buflen)
: _header (id, buflen),
_buf (buf),
_buflen (buflen)
{
assert ((!_buf && !_buflen) || (_buf && _buflen));
}
client_request::~client_request ()
{}
#ifdef __INSIDE_CYGWIN__
int
client_request::make_request ()
{
assert (cygserver_running == CYGSERVER_UNKNOWN \
|| cygserver_running == CYGSERVER_OK \
|| cygserver_running == CYGSERVER_UNAVAIL);
if (cygserver_running == CYGSERVER_UNKNOWN)
cygserver_init ();
assert (cygserver_running == CYGSERVER_OK \
|| cygserver_running == CYGSERVER_UNAVAIL);
/* Don't retry every request if the server's not there */
if (cygserver_running == CYGSERVER_UNAVAIL)
{
syscall_printf ("cygserver un-available");
error_code (ENOSYS);
return -1;
}
transport_layer_base *const transport = create_server_transport ();
assert (transport);
if (transport->connect () == -1)
{
if (errno)
error_code (errno);
else
error_code (ENOSYS);
delete transport;
return -1;
}
// verbose: debug_printf ("connected to server %p", transport);
send (transport);
delete transport;
return 0;
}
bool
check_cygserver_available ()
{
assert (cygserver_running == CYGSERVER_UNKNOWN \
|| cygserver_running == CYGSERVER_UNAVAIL);
cygserver_running = CYGSERVER_OK; // For make_request ().
client_request_get_version req;
/* This indicates that we failed to connect to cygserver at all but
* that's fine as cygwin doesn't need it to be running.
*/
if (req.make_request () == -1)
return false;
/* We connected to the server but something went wrong after that
* (in sending the message, in cygserver itself, or in receiving the
* reply).
*/
if (req.error_code ())
{
syscall_printf ("failure in cygserver version request: %d",
req.error_code ());
syscall_printf ("process will continue without cygserver support");
return false;
}
return req.check_version ();
}
void
cygserver_init ()
{
assert (cygserver_running == CYGSERVER_UNKNOWN \
|| cygserver_running == CYGSERVER_OK \
|| cygserver_running == CYGSERVER_UNAVAIL);
if (cygserver_running == CYGSERVER_OK)
return;
if (!check_cygserver_available ())
cygserver_running = CYGSERVER_UNAVAIL;
}
#endif /* __INSIDE_CYGWIN__ */