xrdp/common/trans.h

182 lines
5.6 KiB
C

/**
* xrdp: A Remote Desktop Protocol server.
*
* Copyright (C) Jay Sorg 2004-2014
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* generic transport
*/
#if !defined(TRANS_H)
#define TRANS_H
#include "arch.h"
#include "parse.h"
#define TRANS_MODE_TCP 1 /* tcp6 if defined, else tcp4 */
#define TRANS_MODE_UNIX 2
#define TRANS_MODE_VSOCK 3
#define TRANS_MODE_TCP4 4 /* tcp4 only */
#define TRANS_MODE_TCP6 6 /* tcp6 only */
#define TRANS_TYPE_LISTENER 1
#define TRANS_TYPE_SERVER 2
#define TRANS_TYPE_CLIENT 3
#define TRANS_STATUS_DOWN 0
#define TRANS_STATUS_UP 1
struct trans; /* forward declaration */
struct xrdp_tls;
typedef int (*ttrans_data_in)(struct trans *self);
typedef int (*ttrans_conn_in)(struct trans *self,
struct trans *new_self);
typedef int (*tis_term)(void);
typedef int (*trans_recv_proc) (struct trans *self, char *ptr, int len);
typedef int (*trans_send_proc) (struct trans *self, const char *data, int len);
typedef int (*trans_can_recv_proc) (struct trans *self, int sck, int millis);
/* optional source info */
enum xrdp_source
{
XRDP_SOURCE_NONE = 0,
XRDP_SOURCE_CLIENT,
XRDP_SOURCE_SESMAN,
XRDP_SOURCE_CHANSRV,
XRDP_SOURCE_MOD,
XRDP_SOURCE_MAX_COUNT
};
/*
* @brief Provide flow control mechanism for (primarily) xrdp
*
* There is one of these data structures per-program.
*
* While input is being read from a 'struct trans' and processed, the
* cur_source member is set to the my_source member from the transport.
* During this processing, trans_write_copy() may be called to send output
* on another struct trans. If this happens, and the output needs to be
* buffered, trans_write_copy() can add the number of bytes generated by
* the input trans to the source field for the cur_source. This allows us to
* see how much output has been buffered for each input source.
*
* When the program assembles 'struct trans' objects to scan for input
* (normally in trans_get_wait_objs()), it is able to see how much buffered
* output is registered for each input. Inputs which have too much buffered
* output owing are skipped, and not considered for input.
*
* This provides a simple means of providing back-pressure on an input
* where the data it is providing is being processed and then sent out on
* a much slower link.
*/
struct source_info
{
enum xrdp_source cur_source;
int source[XRDP_SOURCE_MAX_COUNT];
};
struct trans
{
tbus sck; /* socket handle */
int mode; /* 1 tcp, 2 unix socket, 3 vsock */
int status;
int type1; /* 1 listener 2 server 3 client */
ttrans_data_in trans_data_in;
ttrans_conn_in trans_conn_in;
void *callback_data;
unsigned int header_size;
struct stream *in_s;
struct stream *out_s;
char *listen_filename;
tis_term is_term; /* used to test for exit */
struct stream *wait_s;
int no_stream_init_on_data_in;
int extra_flags; /* user defined */
void *extra_data; /* user defined */
void (*extra_destructor)(struct trans *); /* user defined */
struct ssl_tls *tls;
const char *ssl_protocol; /* e.g. TLSv1, TLSv1.1, TLSv1.2, unknown */
const char *cipher_name; /* e.g. AES256-GCM-SHA384 */
trans_recv_proc trans_recv;
trans_send_proc trans_send;
trans_can_recv_proc trans_can_recv;
struct source_info *si;
enum xrdp_source my_source;
};
struct trans *
trans_create(int mode, int in_size, int out_size);
void
trans_delete(struct trans *self);
void
trans_delete_from_child(struct trans *self);
int
trans_get_wait_objs(struct trans *self, tbus *objs, int *count);
int
trans_get_wait_objs_rw(struct trans *self,
tbus *robjs, int *rcount,
tbus *wobjs, int *wcount, int *timeout);
int
trans_check_wait_objs(struct trans *self);
int
trans_force_read_s(struct trans *self, struct stream *in_s, int size);
int
trans_force_write_s(struct trans *self, struct stream *out_s);
int
trans_force_read(struct trans *self, int size);
int
trans_force_write(struct trans *self);
int
trans_write_copy(struct trans *self);
int
trans_write_copy_s(struct trans *self, struct stream *out_s);
/**
* Connect the transport to the specified destination
*
* @param self Transport
* @param server Destination server (TCP transports only)
* @param port TCP port, or UNIX socket to connect to
* @param timeout in milli-seconds for the operation
* @return 0 for success
*
* Multiple connection attempts may be made within the timeout period.
*
* If the operation is successful, 0 is returned and self->status will
* be TRANS_STATUS_UP
*/
int
trans_connect(struct trans *self, const char *server, const char *port,
int timeout);
int
trans_listen_address(struct trans *self, const char *port, const char *address);
int
trans_listen(struct trans *self, const char *port);
struct stream *
trans_get_in_s(struct trans *self);
struct stream *
trans_get_out_s(struct trans *self, int size);
int
trans_set_tls_mode(struct trans *self, const char *key, const char *cert,
long ssl_protocols, const char *tls_ciphers);
int
trans_shutdown_tls_mode(struct trans *self);
int
trans_tcp_force_read_s(struct trans *self, struct stream *in_s, int size);
#endif