source: branches/samba-3.5.x/source4/libcli/raw/clitransport.c

/* 
   Unix SMB/CIFS implementation.
   SMB client transport context management functions

   Copyright (C) Andrew Tridgell 1994-2005
   Copyright (C) James Myers 2003 <myersjj@samba.org>
   
   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 "libcli/raw/libcliraw.h"
#include "libcli/raw/raw_proto.h"
#include "lib/socket/socket.h"
#include "../lib/util/dlinklist.h"
#include "lib/events/events.h"
#include "lib/stream/packet.h"
#include "librpc/gen_ndr/ndr_nbt.h"
#include "../libcli/nbt/libnbt.h"


/*
  an event has happened on the socket
*/
static void smbcli_transport_event_handler(struct tevent_context *ev, 
                                           struct tevent_fd *fde, 
                                           uint16_t flags, void *private_data)
{
        struct smbcli_transport *transport = talloc_get_type(private_data,
                                                             struct smbcli_transport);
        if (flags & EVENT_FD_READ) {
                packet_recv(transport->packet);
                return;
        }
        if (flags & EVENT_FD_WRITE) {
                packet_queue_run(transport->packet);
        }
}

/*
  destroy a transport
 */
static int transport_destructor(struct smbcli_transport *transport)
{
        smbcli_transport_dead(transport, NT_STATUS_LOCAL_DISCONNECT);
        return 0;
}


/*
  handle receive errors
*/
static void smbcli_transport_error(void *private_data, NTSTATUS status)
{
        struct smbcli_transport *transport = talloc_get_type(private_data, struct smbcli_transport);
        smbcli_transport_dead(transport, status);
}

static NTSTATUS smbcli_transport_finish_recv(void *private_data, DATA_BLOB blob);

/*
  create a transport structure based on an established socket
*/
struct smbcli_transport *smbcli_transport_init(struct smbcli_socket *sock,
                                               TALLOC_CTX *parent_ctx, 
                                               bool primary, 
                                               struct smbcli_options *options,
                                                   struct smb_iconv_convenience *iconv_convenience)
{
        struct smbcli_transport *transport;

        transport = talloc_zero(parent_ctx, struct smbcli_transport);
        if (!transport) return NULL;

        if (primary) {
                transport->socket = talloc_steal(transport, sock);
        } else {
                transport->socket = talloc_reference(transport, sock);
        }
        transport->negotiate.protocol = PROTOCOL_NT1;
        transport->options = *options;
        transport->negotiate.max_xmit = transport->options.max_xmit;
        transport->iconv_convenience = iconv_convenience;

        /* setup the stream -> packet parser */
        transport->packet = packet_init(transport);
        if (transport->packet == NULL) {
                talloc_free(transport);
                return NULL;
        }
        packet_set_private(transport->packet, transport);
        packet_set_socket(transport->packet, transport->socket->sock);
        packet_set_callback(transport->packet, smbcli_transport_finish_recv);
        packet_set_full_request(transport->packet, packet_full_request_nbt);
        packet_set_error_handler(transport->packet, smbcli_transport_error);
        packet_set_event_context(transport->packet, transport->socket->event.ctx);
        packet_set_nofree(transport->packet);
        packet_set_initial_read(transport->packet, 4);

        smbcli_init_signing(transport);

        ZERO_STRUCT(transport->called);

        /* take over event handling from the socket layer - it only
           handles events up until we are connected */
        talloc_free(transport->socket->event.fde);
        transport->socket->event.fde = event_add_fd(transport->socket->event.ctx,
                                                    transport->socket->sock,
                                                    socket_get_fd(transport->socket->sock),
                                                    EVENT_FD_READ,
                                                    smbcli_transport_event_handler,
                                                    transport);

        packet_set_fde(transport->packet, transport->socket->event.fde);
        packet_set_serialise(transport->packet);
        talloc_set_destructor(transport, transport_destructor);

        return transport;
}

/*
  mark the transport as dead
*/
void smbcli_transport_dead(struct smbcli_transport *transport, NTSTATUS status)
{
        smbcli_sock_dead(transport->socket);

        if (NT_STATUS_EQUAL(NT_STATUS_UNSUCCESSFUL, status)) {
                status = NT_STATUS_UNEXPECTED_NETWORK_ERROR;
        }

        /* kill only the first pending receive - this is so that if
         that async function frees the connection we don't die trying
         to use old memory. The caller has to cope with only one
         network error */
        if (transport->pending_recv) {
                struct smbcli_request *req = transport->pending_recv;
                req->state = SMBCLI_REQUEST_ERROR;
                req->status = status;
                DLIST_REMOVE(transport->pending_recv, req);
                if (req->async.fn) {
                        req->async.fn(req);
                }
        }
}


/*
  send a session request
*/
struct smbcli_request *smbcli_transport_connect_send(struct smbcli_transport *transport,
                                                     struct nbt_name *calling, 
                                                     struct nbt_name *called)
{
        uint8_t *p;
        struct smbcli_request *req;
        DATA_BLOB calling_blob, called_blob;
        TALLOC_CTX *tmp_ctx = talloc_new(transport);
        NTSTATUS status;

        status = nbt_name_dup(transport, called, &transport->called);
        if (!NT_STATUS_IS_OK(status)) goto failed;
        
        status = nbt_name_to_blob(tmp_ctx, transport->iconv_convenience, &calling_blob, calling);
        if (!NT_STATUS_IS_OK(status)) goto failed;

        status = nbt_name_to_blob(tmp_ctx, transport->iconv_convenience, &called_blob, called);
        if (!NT_STATUS_IS_OK(status)) goto failed;

        /* allocate output buffer */
        req = smbcli_request_setup_nonsmb(transport, 
                                          NBT_HDR_SIZE + 
                                          calling_blob.length + called_blob.length);
        if (req == NULL) goto failed;

        /* put in the destination name */
        p = req->out.buffer + NBT_HDR_SIZE;
        memcpy(p, called_blob.data, called_blob.length);
        p += called_blob.length;

        memcpy(p, calling_blob.data, calling_blob.length);
        p += calling_blob.length;

        _smb_setlen(req->out.buffer, PTR_DIFF(p, req->out.buffer) - NBT_HDR_SIZE);
        SCVAL(req->out.buffer,0,0x81);

        if (!smbcli_request_send(req)) {
                smbcli_request_destroy(req);
                goto failed;
        }

        talloc_free(tmp_ctx);
        return req;

failed:
        talloc_free(tmp_ctx);
        return NULL;
}

/*
  map a session request error to a NTSTATUS
 */
static NTSTATUS map_session_refused_error(uint8_t error)
{
        switch (error) {
        case 0x80:
        case 0x81:
                return NT_STATUS_REMOTE_NOT_LISTENING;
        case 0x82:
                return NT_STATUS_RESOURCE_NAME_NOT_FOUND;
        case 0x83:
                return NT_STATUS_REMOTE_RESOURCES;
        }
        return NT_STATUS_UNEXPECTED_IO_ERROR;
}


/*
  finish a smbcli_transport_connect()
*/
NTSTATUS smbcli_transport_connect_recv(struct smbcli_request *req)
{
        NTSTATUS status;

        if (!smbcli_request_receive(req)) {
                smbcli_request_destroy(req);
                return NT_STATUS_UNEXPECTED_NETWORK_ERROR;
        }

        switch (CVAL(req->in.buffer,0)) {
        case 0x82:
                status = NT_STATUS_OK;
                break;
        case 0x83:
                status = map_session_refused_error(CVAL(req->in.buffer,4));
                break;
        case 0x84:
                DEBUG(1,("Warning: session retarget not supported\n"));
                status = NT_STATUS_NOT_SUPPORTED;
                break;
        default:
                status = NT_STATUS_UNEXPECTED_IO_ERROR;
                break;
        }

        smbcli_request_destroy(req);
        return status;
}


/*
  send a session request (if needed)
*/
bool smbcli_transport_connect(struct smbcli_transport *transport,
                              struct nbt_name *calling, 
                              struct nbt_name *called)
{
        struct smbcli_request *req;
        NTSTATUS status;

        if (transport->socket->port == 445) {
                return true;
        }

        req = smbcli_transport_connect_send(transport, 
                                            calling, called);
        status = smbcli_transport_connect_recv(req);
        return NT_STATUS_IS_OK(status);
}

/****************************************************************************
get next mid in sequence
****************************************************************************/
uint16_t smbcli_transport_next_mid(struct smbcli_transport *transport)
{
        uint16_t mid;
        struct smbcli_request *req;

        mid = transport->next_mid;

again:
        /* now check to see if this mid is being used by one of the 
           pending requests. This is quite efficient because the list is
           usually very short */

        /* the zero mid is reserved for requests that don't have a mid */
        if (mid == 0) mid = 1;

        for (req=transport->pending_recv; req; req=req->next) {
                if (req->mid == mid) {
                        mid++;
                        goto again;
                }
        }

        transport->next_mid = mid+1;
        return mid;
}

static void idle_handler(struct tevent_context *ev, 
                         struct tevent_timer *te, struct timeval t, void *private_data)
{
        struct smbcli_transport *transport = talloc_get_type(private_data,
                                                             struct smbcli_transport);
        struct timeval next = timeval_add(&t, 0, transport->idle.period);
        transport->socket->event.te = event_add_timed(transport->socket->event.ctx, 
                                                      transport,
                                                      next,
                                                      idle_handler, transport);
        transport->idle.func(transport, transport->idle.private_data);
}

/*
  setup the idle handler for a transport
  the period is in microseconds
*/
_PUBLIC_ void smbcli_transport_idle_handler(struct smbcli_transport *transport, 
                                   void (*idle_func)(struct smbcli_transport *, void *),
                                   uint64_t period,
                                   void *private_data)
{
        transport->idle.func = idle_func;
        transport->idle.private_data = private_data;
        transport->idle.period = period;

        if (transport->socket->event.te != NULL) {
                talloc_free(transport->socket->event.te);
        }

        transport->socket->event.te = event_add_timed(transport->socket->event.ctx, 
                                                      transport,
                                                      timeval_current_ofs(0, period),
                                                      idle_handler, transport);
}

/*
  we have a full request in our receive buffer - match it to a pending request
  and process
 */
static NTSTATUS smbcli_transport_finish_recv(void *private_data, DATA_BLOB blob)
{
        struct smbcli_transport *transport = talloc_get_type(private_data,
                                                             struct smbcli_transport);
        uint8_t *buffer, *hdr, *vwv;
        int len;
        uint16_t wct=0, mid = 0, op = 0;
        struct smbcli_request *req = NULL;

        buffer = blob.data;
        len = blob.length;

        hdr = buffer+NBT_HDR_SIZE;
        vwv = hdr + HDR_VWV;

        /* see if it could be an oplock break request */
        if (smbcli_handle_oplock_break(transport, len, hdr, vwv)) {
                talloc_free(buffer);
                return NT_STATUS_OK;
        }

        /* at this point we need to check for a readbraw reply, as
           these can be any length */
        if (transport->readbraw_pending) {
                transport->readbraw_pending = 0;

                /* it must match the first entry in the pending queue
                   as the client is not allowed to have outstanding
                   readbraw requests */
                req = transport->pending_recv;
                if (!req) goto error;

                req->in.buffer = buffer;
                talloc_steal(req, buffer);
                req->in.size = len;
                req->in.allocated = req->in.size;
                goto async;
        }

        if (len >= MIN_SMB_SIZE) {
                /* extract the mid for matching to pending requests */
                mid = SVAL(hdr, HDR_MID);
                wct = CVAL(hdr, HDR_WCT);
                op  = CVAL(hdr, HDR_COM);
        }

        /* match the incoming request against the list of pending requests */
        for (req=transport->pending_recv; req; req=req->next) {
                if (req->mid == mid) break;
        }

        /* see if it's a ntcancel reply for the current MID */
        req = smbcli_handle_ntcancel_reply(req, len, hdr);

        if (!req) {
                DEBUG(1,("Discarding unmatched reply with mid %d op %d\n", mid, op));
                goto error;
        }

        /* fill in the 'in' portion of the matching request */
        req->in.buffer = buffer;
        talloc_steal(req, buffer);
        req->in.size = len;
        req->in.allocated = req->in.size;

        /* handle NBT session replies */
        if (req->in.size >= 4 && req->in.buffer[0] != 0) {
                req->status = NT_STATUS_OK;
                goto async;
        }

        /* handle non-SMB replies */
        if (req->in.size < NBT_HDR_SIZE + MIN_SMB_SIZE) {
                req->state = SMBCLI_REQUEST_ERROR;
                goto error;
        }

        if (req->in.size < NBT_HDR_SIZE + MIN_SMB_SIZE + VWV(wct)) {
                DEBUG(2,("bad reply size for mid %d\n", mid));
                req->status = NT_STATUS_UNSUCCESSFUL;
                req->state = SMBCLI_REQUEST_ERROR;
                goto error;
        }

        req->in.hdr = hdr;
        req->in.vwv = vwv;
        req->in.wct = wct;
        if (req->in.size >= NBT_HDR_SIZE + MIN_SMB_SIZE + VWV(wct)) {
                req->in.data = req->in.vwv + VWV(wct) + 2;
                req->in.data_size = SVAL(req->in.vwv, VWV(wct));
                if (req->in.size < NBT_HDR_SIZE + MIN_SMB_SIZE + VWV(wct) + req->in.data_size) {
                        DEBUG(3,("bad data size for mid %d\n", mid));
                        /* blergh - w2k3 gives a bogus data size values in some
                           openX replies */
                        req->in.data_size = req->in.size - (NBT_HDR_SIZE + MIN_SMB_SIZE + VWV(wct));
                }
        }
        req->in.ptr = req->in.data;
        req->flags2 = SVAL(req->in.hdr, HDR_FLG2);

        smb_setup_bufinfo(req);

        if (!(req->flags2 & FLAGS2_32_BIT_ERROR_CODES)) {
                int eclass = CVAL(req->in.hdr,HDR_RCLS);
                int code = SVAL(req->in.hdr,HDR_ERR);
                if (eclass == 0 && code == 0) {
                        transport->error.e.nt_status = NT_STATUS_OK;
                } else {
                        transport->error.e.nt_status = NT_STATUS_DOS(eclass, code);
                }
        } else {
                transport->error.e.nt_status = NT_STATUS(IVAL(req->in.hdr, HDR_RCLS));
        }

        req->status = transport->error.e.nt_status;
        if (NT_STATUS_IS_OK(req->status)) {
                transport->error.etype = ETYPE_NONE;
        } else {
                transport->error.etype = ETYPE_SMB;
        }

        if (!smbcli_request_check_sign_mac(req)) {
                transport->error.etype = ETYPE_SOCKET;
                transport->error.e.socket_error = SOCKET_READ_BAD_SIG;
                req->state = SMBCLI_REQUEST_ERROR;
                req->status = NT_STATUS_ACCESS_DENIED;
                goto error;
        };

async:
        /* if this request has an async handler then call that to
           notify that the reply has been received. This might destroy
           the request so it must happen last */

        req->state = SMBCLI_REQUEST_DONE;

        if (req->recv_helper.fn) {
                /*
                 * let the recv helper decide in
                 * what state the request really is
                 */
                req->state = req->recv_helper.fn(req);

                /* if more parts are needed, wait for them */
                if (req->state <= SMBCLI_REQUEST_RECV) {
                        return NT_STATUS_OK;
                }
        }
        DLIST_REMOVE(transport->pending_recv, req);
        if (req->async.fn) {
                req->async.fn(req);
        }
        return NT_STATUS_OK;

error:
        if (req) {
                DLIST_REMOVE(transport->pending_recv, req);
                req->state = SMBCLI_REQUEST_ERROR;
                if (req->async.fn) {
                        req->async.fn(req);
                }
        } else {
                talloc_free(buffer);
        }
        return NT_STATUS_OK;
}

/*
  process some read/write requests that are pending
  return false if the socket is dead
*/
_PUBLIC_ bool smbcli_transport_process(struct smbcli_transport *transport)
{
        NTSTATUS status;
        size_t npending;

        packet_queue_run(transport->packet);
        if (transport->socket->sock == NULL) {
                return false;
        }

        status = socket_pending(transport->socket->sock, &npending);
        if (NT_STATUS_IS_OK(status) && npending > 0) {
                packet_recv(transport->packet);
        }
        if (transport->socket->sock == NULL) {
                return false;
        }
        return true;
}

/*
  handle timeouts of individual smb requests
*/
static void smbcli_timeout_handler(struct tevent_context *ev, struct tevent_timer *te, 
                                   struct timeval t, void *private_data)
{
        struct smbcli_request *req = talloc_get_type(private_data, struct smbcli_request);

        if (req->state == SMBCLI_REQUEST_RECV) {
                DLIST_REMOVE(req->transport->pending_recv, req);
        }
        req->status = NT_STATUS_IO_TIMEOUT;
        req->state = SMBCLI_REQUEST_ERROR;
        if (req->async.fn) {
                req->async.fn(req);
        }
}


/*
  destroy a request
*/
static int smbcli_request_destructor(struct smbcli_request *req)
{
        if (req->state == SMBCLI_REQUEST_RECV) {
                DLIST_REMOVE(req->transport->pending_recv, req);
        }
        return 0;
}


/*
  put a request into the send queue
*/
void smbcli_transport_send(struct smbcli_request *req)
{
        DATA_BLOB blob;
        NTSTATUS status;

        /* check if the transport is dead */
        if (req->transport->socket->sock == NULL) {
                req->state = SMBCLI_REQUEST_ERROR;
                req->status = NT_STATUS_NET_WRITE_FAULT;
                return;
        }

        blob = data_blob_const(req->out.buffer, req->out.size);
        status = packet_send(req->transport->packet, blob);
        if (!NT_STATUS_IS_OK(status)) {
                req->state = SMBCLI_REQUEST_ERROR;
                req->status = status;
                return;
        }

        packet_queue_run(req->transport->packet);
        if (req->transport->socket->sock == NULL) {
                req->state = SMBCLI_REQUEST_ERROR;
                req->status = NT_STATUS_NET_WRITE_FAULT;
                return;
        }

        if (req->one_way_request) {
                req->state = SMBCLI_REQUEST_DONE;
                smbcli_request_destroy(req);
                return;
        }

        req->state = SMBCLI_REQUEST_RECV;
        DLIST_ADD(req->transport->pending_recv, req);

        /* add a timeout */
        if (req->transport->options.request_timeout) {
                event_add_timed(req->transport->socket->event.ctx, req, 
                                timeval_current_ofs(req->transport->options.request_timeout, 0), 
                                smbcli_timeout_handler, req);
        }

        talloc_set_destructor(req, smbcli_request_destructor);
}


/****************************************************************************
 Send an SMBecho (async send)
*****************************************************************************/
_PUBLIC_ struct smbcli_request *smb_raw_echo_send(struct smbcli_transport *transport,
                                         struct smb_echo *p)
{
        struct smbcli_request *req;

        req = smbcli_request_setup_transport(transport, SMBecho, 1, p->in.size);
        if (!req) return NULL;

        SSVAL(req->out.vwv, VWV(0), p->in.repeat_count);

        memcpy(req->out.data, p->in.data, p->in.size);

        ZERO_STRUCT(p->out);

        if (!smbcli_request_send(req)) {
                smbcli_request_destroy(req);
                return NULL;
        }

        return req;
}

/****************************************************************************
 raw echo interface (async recv)
****************************************************************************/
NTSTATUS smb_raw_echo_recv(struct smbcli_request *req, TALLOC_CTX *mem_ctx,
                           struct smb_echo *p)
{
        if (!smbcli_request_receive(req) ||
            smbcli_request_is_error(req)) {
                goto failed;
        }

        SMBCLI_CHECK_WCT(req, 1);
        p->out.count++;
        p->out.sequence_number = SVAL(req->in.vwv, VWV(0));
        p->out.size = req->in.data_size;
        talloc_free(p->out.data);
        p->out.data = talloc_array(mem_ctx, uint8_t, p->out.size);
        NT_STATUS_HAVE_NO_MEMORY(p->out.data);

        if (!smbcli_raw_pull_data(&req->in.bufinfo, req->in.data, p->out.size, p->out.data)) {
                req->status = NT_STATUS_BUFFER_TOO_SMALL;
        }

        if (p->out.count == p->in.repeat_count) {
                return smbcli_request_destroy(req);
        }

        return NT_STATUS_OK;

failed:
        return smbcli_request_destroy(req);
}

/****************************************************************************
 Send a echo (sync interface)
*****************************************************************************/
NTSTATUS smb_raw_echo(struct smbcli_transport *transport, struct smb_echo *p)
{
        struct smbcli_request *req = smb_raw_echo_send(transport, p);
        return smbcli_request_simple_recv(req);
}