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/*
Unix SMB/CIFS implementation.
helper functions for stream based servers
Copyright (C) Andrew Tridgell 2003-2005
Copyright (C) Stefan (metze) Metzmacher 2004
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 2 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, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "includes.h"
#include "process_model.h"
#include "events.h"
#include "smbd/service_stream.h"
/* the range of ports to try for dcerpc over tcp endpoints */
#define SERVER_TCP_LOW_PORT 1024
#define SERVER_TCP_HIGH_PORT 1300
/* size of listen() backlog in smbd */
#define SERVER_LISTEN_BACKLOG 10
/*
private structure for a single listening stream socket
*/
struct stream_socket {
const struct stream_server_ops *ops;
struct event_context *event_ctx;
const struct model_ops *model_ops;
struct socket_context *sock;
void *private;
};
/*
close the socket and shutdown a stream_connection
*/
void stream_terminate_connection(struct stream_connection *srv_conn, const char *reason)
{
struct event_context *event_ctx = srv_conn->event.ctx;
const struct model_ops *model_ops = srv_conn->model_ops;
talloc_free(srv_conn);
model_ops->terminate(event_ctx, reason);
}
/*
the select loop has indicated that a stream is ready for IO
*/
static void stream_io_handler(struct event_context *ev, struct fd_event *fde,
struct timeval t, uint16_t flags)
{
struct stream_connection *conn = talloc_get_type(fde->private,
struct stream_connection);
if (flags & EVENT_FD_WRITE) {
conn->ops->send_handler(conn, t, flags);
return;
}
if (flags & EVENT_FD_READ) {
conn->ops->recv_handler(conn, t, flags);
}
}
/*
called when a new socket connection has been established. This is called in the process
context of the new process (if appropriate)
*/
static void stream_new_connection(struct event_context *ev,
struct socket_context *sock,
uint32_t server_id, void *private)
{
struct stream_socket *stream_socket = talloc_get_type(private, struct stream_socket);
struct fd_event fde;
struct stream_connection *srv_conn;
srv_conn = talloc_zero(ev, struct stream_connection);
if (!srv_conn) {
DEBUG(0,("talloc(mem_ctx, struct stream_connection) failed\n"));
return;
}
talloc_steal(srv_conn, sock);
fde.private = srv_conn;
fde.fd = socket_get_fd(sock);
fde.flags = EVENT_FD_READ;
fde.handler = stream_io_handler;
srv_conn->private = stream_socket->private;
srv_conn->model_ops = stream_socket->model_ops;
srv_conn->event.ctx = ev;
srv_conn->event.fde = &fde;
srv_conn->socket = sock;
srv_conn->server_id = server_id;
srv_conn->ops = stream_socket->ops;
srv_conn->event.fde = event_add_fd(ev, &fde, srv_conn);
if (!socket_check_access(sock, "smbd", lp_hostsallow(-1), lp_hostsdeny(-1))) {
stream_terminate_connection(srv_conn, "denied by access rules");
return;
}
/* setup to receive internal messages on this connection */
srv_conn->msg_ctx = messaging_init(srv_conn, srv_conn->server_id, ev);
if (!srv_conn->msg_ctx) {
stream_terminate_connection(srv_conn, "messaging_init() failed");
return;
}
/* call the server specific accept code */
stream_socket->ops->accept_connection(srv_conn);
}
/*
called when someone opens a connection to one of our listening ports
*/
static void stream_accept_handler(struct event_context *ev, struct fd_event *fde,
struct timeval t, uint16_t flags)
{
struct stream_socket *stream_socket = talloc_get_type(fde->private, struct stream_socket);
/* ask the process model to create us a process for this new
connection. When done, it calls stream_new_connection()
with the newly created socket */
stream_socket->model_ops->accept_connection(ev, stream_socket->sock,
stream_new_connection, stream_socket);
}
/*
setup a listen stream socket
if you pass *port == 0, then a port > 1024 is used
*/
NTSTATUS stream_setup_socket(struct event_context *event_context,
const struct model_ops *model_ops,
const struct stream_server_ops *stream_ops,
const char *family,
const char *sock_addr,
uint16_t *port,
void *private)
{
NTSTATUS status;
struct stream_socket *stream_socket;
struct fd_event fde;
int i;
stream_socket = talloc_zero(event_context, struct stream_socket);
NT_STATUS_HAVE_NO_MEMORY(stream_socket);
status = socket_create(family, SOCKET_TYPE_STREAM, &stream_socket->sock, 0);
NT_STATUS_NOT_OK_RETURN(status);
talloc_steal(stream_socket, stream_socket->sock);
/* ready to listen */
status = socket_set_option(stream_socket->sock, "SO_KEEPALIVE", NULL);
NT_STATUS_NOT_OK_RETURN(status);
status = socket_set_option(stream_socket->sock, lp_socket_options(), NULL);
NT_STATUS_NOT_OK_RETURN(status);
/* TODO: set socket ACL's here when they're implemented */
if (*port == 0) {
for (i=SERVER_TCP_LOW_PORT;i<= SERVER_TCP_HIGH_PORT;i++) {
status = socket_listen(stream_socket->sock, sock_addr, i,
SERVER_LISTEN_BACKLOG, 0);
if (NT_STATUS_IS_OK(status)) {
*port = i;
break;
}
}
} else {
status = socket_listen(stream_socket->sock, sock_addr, *port, SERVER_LISTEN_BACKLOG, 0);
}
if (!NT_STATUS_IS_OK(status)) {
DEBUG(0,("Failed to listen on %s:%u - %s\n",
sock_addr, *port, nt_errstr(status)));
talloc_free(stream_socket);
return status;
}
/* we are only interested in read events on the listen socket */
fde.fd = socket_get_fd(stream_socket->sock);
fde.flags = EVENT_FD_READ;
fde.private = stream_socket;
fde.handler = stream_accept_handler;
event_add_fd(event_context, &fde, stream_socket->sock);
stream_socket->private = talloc_reference(stream_socket, private);
stream_socket->ops = stream_ops;
stream_socket->event_ctx = event_context;
stream_socket->model_ops = model_ops;
return NT_STATUS_OK;
}
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