source: branches/samba-3.5.x/source4/smb_server/smb_server.c

/* 
   Unix SMB/CIFS implementation.
   process incoming packets - main loop
   Copyright (C) Andrew Tridgell        2004-2005
   Copyright (C) Stefan Metzmacher      2004-2005
   
   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 3 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, see <http://www.gnu.org/licenses/>.
*/

#include "includes.h"
#include "smbd/service_task.h"
#include "smbd/service_stream.h"
#include "smbd/service.h"
#include "smb_server/smb_server.h"
#include "smb_server/service_smb_proto.h"
#include "lib/messaging/irpc.h"
#include "lib/stream/packet.h"
#include "libcli/smb2/smb2.h"
#include "smb_server/smb2/smb2_server.h"
#include "system/network.h"
#include "lib/socket/netif.h"
#include "param/share.h"
#include "dsdb/samdb/samdb.h"
#include "param/param.h"

static NTSTATUS smbsrv_recv_generic_request(void *private_data, DATA_BLOB blob)
{
        NTSTATUS status;
        struct smbsrv_connection *smb_conn = talloc_get_type(private_data, struct smbsrv_connection);
        uint32_t protocol_version;

        /* see if its a special NBT packet */
        if (CVAL(blob.data,0) != 0) {
                status = smbsrv_init_smb_connection(smb_conn, smb_conn->lp_ctx);
                NT_STATUS_NOT_OK_RETURN(status);
                packet_set_callback(smb_conn->packet, smbsrv_recv_smb_request);
                return smbsrv_recv_smb_request(smb_conn, blob);
        }

        if (blob.length < (NBT_HDR_SIZE + MIN_SMB_SIZE)) {
                DEBUG(2,("Invalid SMB packet length count %ld\n", (long)blob.length));
                smbsrv_terminate_connection(smb_conn, "Invalid SMB packet");
                return NT_STATUS_OK;
        }

        protocol_version = IVAL(blob.data, NBT_HDR_SIZE);

        switch (protocol_version) {
        case SMB_MAGIC:
                status = smbsrv_init_smb_connection(smb_conn, smb_conn->lp_ctx);
                NT_STATUS_NOT_OK_RETURN(status);
                packet_set_callback(smb_conn->packet, smbsrv_recv_smb_request);
                return smbsrv_recv_smb_request(smb_conn, blob);
        case SMB2_MAGIC:
                if (lp_srv_maxprotocol(smb_conn->lp_ctx) < PROTOCOL_SMB2) break;
                status = smbsrv_init_smb2_connection(smb_conn);
                NT_STATUS_NOT_OK_RETURN(status);
                packet_set_callback(smb_conn->packet, smbsrv_recv_smb2_request);
                return smbsrv_recv_smb2_request(smb_conn, blob);
        }

        DEBUG(2,("Invalid SMB packet: protocol prefix: 0x%08X\n", protocol_version));
        smbsrv_terminate_connection(smb_conn, "NON-SMB packet");
        return NT_STATUS_OK;
}

/*
  close the socket and shutdown a server_context
*/
void smbsrv_terminate_connection(struct smbsrv_connection *smb_conn, const char *reason)
{
        stream_terminate_connection(smb_conn->connection, reason);
}

/*
  called when a SMB socket becomes readable
*/
static void smbsrv_recv(struct stream_connection *conn, uint16_t flags)
{
        struct smbsrv_connection *smb_conn = talloc_get_type(conn->private_data,
                                                             struct smbsrv_connection);

        DEBUG(10,("smbsrv_recv\n"));

        packet_recv(smb_conn->packet);
}

/*
  called when a SMB socket becomes writable
*/
static void smbsrv_send(struct stream_connection *conn, uint16_t flags)
{
        struct smbsrv_connection *smb_conn = talloc_get_type(conn->private_data,
                                                             struct smbsrv_connection);
        packet_queue_run(smb_conn->packet);
}

/*
  handle socket recv errors
*/
static void smbsrv_recv_error(void *private_data, NTSTATUS status)
{
        struct smbsrv_connection *smb_conn = talloc_get_type(private_data, struct smbsrv_connection);
        
        smbsrv_terminate_connection(smb_conn, nt_errstr(status));
}

/*
  initialise a server_context from a open socket and register a event handler
  for reading from that socket
*/
static void smbsrv_accept(struct stream_connection *conn)
{
        struct smbsrv_connection *smb_conn;

        DEBUG(5,("smbsrv_accept\n"));

        smb_conn = talloc_zero(conn, struct smbsrv_connection);
        if (!smb_conn) {
                stream_terminate_connection(conn, "out of memory");
                return;
        }

        smb_conn->packet = packet_init(smb_conn);
        if (!smb_conn->packet) {
                smbsrv_terminate_connection(smb_conn, "out of memory");
                return;
        }
        packet_set_private(smb_conn->packet, smb_conn);
        packet_set_socket(smb_conn->packet, conn->socket);
        packet_set_callback(smb_conn->packet, smbsrv_recv_generic_request);
        packet_set_full_request(smb_conn->packet, packet_full_request_nbt);
        packet_set_error_handler(smb_conn->packet, smbsrv_recv_error);
        packet_set_event_context(smb_conn->packet, conn->event.ctx);
        packet_set_fde(smb_conn->packet, conn->event.fde);
        packet_set_serialise(smb_conn->packet);
        packet_set_initial_read(smb_conn->packet, 4);

        smb_conn->lp_ctx = conn->lp_ctx;
        smb_conn->connection = conn;
        conn->private_data = smb_conn;

        smb_conn->statistics.connect_time = timeval_current();

        smbsrv_management_init(smb_conn);

        irpc_add_name(conn->msg_ctx, "smb_server");

        if (!NT_STATUS_IS_OK(share_get_context_by_name(smb_conn, lp_share_backend(smb_conn->lp_ctx), 
                                                       smb_conn->connection->event.ctx,
                                                       smb_conn->lp_ctx, &(smb_conn->share_context)))) {
                smbsrv_terminate_connection(smb_conn, "share_init failed!");
                return;
        }
}

static const struct stream_server_ops smb_stream_ops = {
        .name                   = "smbsrv",
        .accept_connection      = smbsrv_accept,
        .recv_handler           = smbsrv_recv,
        .send_handler           = smbsrv_send,
};

/*
  setup a listening socket on all the SMB ports for a particular address
*/
_PUBLIC_ NTSTATUS smbsrv_add_socket(struct tevent_context *event_context,
                                    struct loadparm_context *lp_ctx,
                               const struct model_ops *model_ops,
                               const char *address)
{
        const char **ports = lp_smb_ports(lp_ctx);
        int i;
        NTSTATUS status;

        for (i=0;ports[i];i++) {
                uint16_t port = atoi(ports[i]);
                if (port == 0) continue;
                status = stream_setup_socket(event_context, lp_ctx, 
                                             model_ops, &smb_stream_ops, 
                                             "ipv4", address, &port, 
                                             lp_socket_options(lp_ctx), 
                                             NULL);
                NT_STATUS_NOT_OK_RETURN(status);
        }

        return NT_STATUS_OK;
}


/*
  pre-open some of our ldb databases, to prevent an explosion of memory usage
  when we fork
 */
static void smbsrv_preopen_ldb(struct task_server *task)
{
        /* yes, this looks strange. It is a hack to preload the
           schema. I'd like to share most of the ldb context with the
           child too. That will come later */
        talloc_free(samdb_connect(task, task->event_ctx, task->lp_ctx, NULL));
}

/*
  open the smb server sockets
*/
static void smbsrv_task_init(struct task_server *task)
{       
        NTSTATUS status;

        task_server_set_title(task, "task[smbsrv]");

        if (lp_interfaces(task->lp_ctx) && lp_bind_interfaces_only(task->lp_ctx)) {
                int num_interfaces;
                int i;
                struct interface *ifaces;

                load_interfaces(task, lp_interfaces(task->lp_ctx), &ifaces);

                num_interfaces = iface_count(ifaces);

                /* We have been given an interfaces line, and been 
                   told to only bind to those interfaces. Create a
                   socket per interface and bind to only these.
                */
                for(i = 0; i < num_interfaces; i++) {
                        const char *address = iface_n_ip(ifaces, i);
                        status = smbsrv_add_socket(task->event_ctx, task->lp_ctx, task->model_ops, address);
                        if (!NT_STATUS_IS_OK(status)) goto failed;
                }
        } else {
                /* Just bind to lp_socket_address() (usually 0.0.0.0) */
                status = smbsrv_add_socket(task->event_ctx, task->lp_ctx, task->model_ops, 
                                           lp_socket_address(task->lp_ctx));
                if (!NT_STATUS_IS_OK(status)) goto failed;
        }

        smbsrv_preopen_ldb(task);

        return;
failed:
        task_server_terminate(task, "Failed to startup smb server task", true); 
}

/* called at smbd startup - register ourselves as a server service */
NTSTATUS server_service_smb_init(void)
{
        share_init();
        return register_server_service("smb", smbsrv_task_init);
}