source4/libcli/smb2/transport.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    SMB2 client transport context management functions
   5
   6    Copyright (C) Andrew Tridgell 2005
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21 */
  22
  23 #include "includes.h"
  24 #include "libcli/raw/libcliraw.h"
  25 #include "libcli/smb2/smb2.h"
  26 #include "libcli/smb2/smb2_calls.h"
  27 #include "lib/socket/socket.h"
  28 #include "lib/events/events.h"
  29 #include "lib/stream/packet.h"
  30 #include "include/dlinklist.h"
  31
  32
  33 /*
  34   an event has happened on the socket
  35 */
  36 static void smb2_transport_event_handler(struct event_context *ev,
  37                                          struct fd_event *fde,
  38                                          uint16_t flags, void *private)
  39 {
  40         struct smb2_transport *transport = talloc_get_type(private,
  41                                                            struct smb2_transport);
  42         if (flags & EVENT_FD_READ) {
  43                 packet_recv(transport->packet);
  44                 return;
  45         }
  46         if (flags & EVENT_FD_WRITE) {
  47                 packet_queue_run(transport->packet);
  48         }
  49 }
  50
  51 /*
  52   destroy a transport
  53  */
  54 static int transport_destructor(struct smb2_transport *transport)
  55 {
  56         smb2_transport_dead(transport, NT_STATUS_LOCAL_DISCONNECT);
  57         return 0;
  58 }
  59
  60
  61 /*
  62   handle receive errors
  63 */
  64 static void smb2_transport_error(void *private, NTSTATUS status)
  65 {
  66         struct smb2_transport *transport = talloc_get_type(private,
  67                                                            struct smb2_transport);
  68         smb2_transport_dead(transport, status);
  69 }
  70
  71 static NTSTATUS smb2_transport_finish_recv(void *private, DATA_BLOB blob);
  72
  73 /*
  74   create a transport structure based on an established socket
  75 */
  76 struct smb2_transport *smb2_transport_init(struct smbcli_socket *sock,
  77                                            TALLOC_CTX *parent_ctx)
  78 {
  79         struct smb2_transport *transport;
  80
  81         transport = talloc_zero(parent_ctx, struct smb2_transport);
  82         if (!transport) return NULL;
  83
  84         transport->socket = talloc_steal(transport, sock);
  85
  86         /* setup the stream -> packet parser */
  87         transport->packet = packet_init(transport);
  88         if (transport->packet == NULL) {
  89                 talloc_free(transport);
  90                 return NULL;
  91         }
  92         packet_set_private(transport->packet, transport);
  93         packet_set_socket(transport->packet, transport->socket->sock);
  94         packet_set_callback(transport->packet, smb2_transport_finish_recv);
  95         packet_set_full_request(transport->packet, packet_full_request_nbt);
  96         packet_set_error_handler(transport->packet, smb2_transport_error);
  97         packet_set_event_context(transport->packet, transport->socket->event.ctx);
  98         packet_set_nofree(transport->packet);
  99
 100         /* take over event handling from the socket layer - it only
 101            handles events up until we are connected */
 102         talloc_free(transport->socket->event.fde);
 103         transport->socket->event.fde = event_add_fd(transport->socket->event.ctx,
 104                                                     transport->socket,
 105                                                     socket_get_fd(transport->socket->sock),
 106                                                     EVENT_FD_READ,
 107                                                     smb2_transport_event_handler,
 108                                                     transport);
 109
 110         packet_set_fde(transport->packet, transport->socket->event.fde);
 111         packet_set_serialise(transport->packet);
 112
 113         talloc_set_destructor(transport, transport_destructor);
 114
 115         transport->options.timeout = 30;
 116
 117         return transport;
 118 }
 119
 120 /*
 121   mark the transport as dead
 122 */
 123 void smb2_transport_dead(struct smb2_transport *transport, NTSTATUS status)
 124 {
 125         smbcli_sock_dead(transport->socket);
 126
 127         if (NT_STATUS_EQUAL(NT_STATUS_UNSUCCESSFUL, status)) {
 128                 status = NT_STATUS_UNEXPECTED_NETWORK_ERROR;
 129         }
 130
 131         /* kill all pending receives */
 132         while (transport->pending_recv) {
 133                 struct smb2_request *req = transport->pending_recv;
 134                 req->state = SMB2_REQUEST_ERROR;
 135                 req->status = status;
 136                 DLIST_REMOVE(transport->pending_recv, req);
 137                 if (req->async.fn) {
 138                         req->async.fn(req);
 139                 }
 140         }
 141 }
 142
 143 /*
 144   we have a full request in our receive buffer - match it to a pending request
 145   and process
 146  */
 147 static NTSTATUS smb2_transport_finish_recv(void *private, DATA_BLOB blob)
 148 {
 149         struct smb2_transport *transport = talloc_get_type(private,
 150                                                              struct smb2_transport);
 151         uint8_t *buffer, *hdr;
 152         int len;
 153         struct smb2_request *req = NULL;
 154         uint64_t seqnum;
 155         uint16_t buffer_code;
 156         uint32_t dynamic_size;
 157
 158         buffer = blob.data;
 159         len = blob.length;
 160
 161         hdr = buffer+NBT_HDR_SIZE;
 162
 163         if (len < SMB2_MIN_SIZE) {
 164                 DEBUG(1,("Discarding smb2 reply of size %d\n", len));
 165                 goto error;
 166         }
 167
 168         seqnum = BVAL(hdr, SMB2_HDR_SEQNUM);
 169
 170         /* match the incoming request against the list of pending requests */
 171         for (req=transport->pending_recv; req; req=req->next) {
 172                 if (req->seqnum == seqnum) break;
 173         }
 174
 175         if (!req) {
 176                 DEBUG(1,("Discarding unmatched reply with seqnum 0x%llx op %d\n",
 177                          (long long)seqnum, SVAL(hdr, SMB2_HDR_OPCODE)));
 178                 goto error;
 179         }
 180
 181         /* fill in the 'in' portion of the matching request */
 182         req->in.buffer = buffer;
 183         talloc_steal(req, buffer);
 184         req->in.size = len;
 185         req->in.allocated = req->in.size;
 186
 187         req->in.hdr       = hdr;
 188         req->in.body      = hdr+SMB2_HDR_BODY;
 189         req->in.body_size = req->in.size - (SMB2_HDR_BODY+NBT_HDR_SIZE);
 190         req->status       = NT_STATUS(IVAL(hdr, SMB2_HDR_STATUS));
 191
 192         if (NT_STATUS_EQUAL(req->status, STATUS_PENDING)) {
 193                 /* the server has helpfully told us that this request is still being
 194                    processed. how useful :) */
 195                 talloc_free(buffer);
 196                 return NT_STATUS_OK;
 197         }
 198
 199         buffer_code = SVAL(req->in.body, 0);
 200         req->in.body_fixed = (buffer_code & ~1);
 201         req->in.dynamic = NULL;
 202         dynamic_size = req->in.body_size - req->in.body_fixed;
 203         if (dynamic_size != 0 && (buffer_code & 1)) {
 204                 req->in.dynamic = req->in.body + req->in.body_fixed;
 205                 if (smb2_oob(&req->in, req->in.dynamic, dynamic_size)) {
 206                         DEBUG(1,("SMB2 request invalid dynamic size 0x%x\n",
 207                                  dynamic_size));
 208                         goto error;
 209                 }
 210         }
 211
 212         DEBUG(2, ("SMB2 RECV seqnum=0x%llx\n", (long long)req->seqnum));
 213         dump_data(5, req->in.body, req->in.body_size);
 214
 215         /* if this request has an async handler then call that to
 216            notify that the reply has been received. This might destroy
 217            the request so it must happen last */
 218         DLIST_REMOVE(transport->pending_recv, req);
 219         req->state = SMB2_REQUEST_DONE;
 220         if (req->async.fn) {
 221                 req->async.fn(req);
 222         }
 223         return NT_STATUS_OK;
 224
 225 error:
 226         dump_data(5, buffer, len);
 227         if (req) {
 228                 DLIST_REMOVE(transport->pending_recv, req);
 229                 req->state = SMB2_REQUEST_ERROR;
 230                 if (req->async.fn) {
 231                         req->async.fn(req);
 232                 }
 233         } else {
 234                 talloc_free(buffer);
 235         }
 236         return NT_STATUS_UNSUCCESSFUL;
 237 }
 238
 239 /*
 240   handle timeouts of individual smb requests
 241 */
 242 static void smb2_timeout_handler(struct event_context *ev, struct timed_event *te,
 243                                  struct timeval t, void *private)
 244 {
 245         struct smb2_request *req = talloc_get_type(private, struct smb2_request);
 246
 247         if (req->state == SMB2_REQUEST_RECV) {
 248                 DLIST_REMOVE(req->transport->pending_recv, req);
 249         }
 250         req->status = NT_STATUS_IO_TIMEOUT;
 251         req->state = SMB2_REQUEST_ERROR;
 252         if (req->async.fn) {
 253                 req->async.fn(req);
 254         }
 255 }
 256
 257
 258 /*
 259   destroy a request
 260 */
 261 static int smb2_request_destructor(struct smb2_request *req)
 262 {
 263         if (req->state == SMB2_REQUEST_RECV) {
 264                 DLIST_REMOVE(req->transport->pending_recv, req);
 265         }
 266         return 0;
 267 }
 268
 269
 270 /*
 271   put a request into the send queue
 272 */
 273 void smb2_transport_send(struct smb2_request *req)
 274 {
 275         DATA_BLOB blob;
 276         NTSTATUS status;
 277
 278         _smb2_setlen(req->out.buffer, req->out.size - NBT_HDR_SIZE);
 279
 280         DEBUG(2, ("SMB2 send seqnum=0x%llx\n", (long long)req->seqnum));
 281         dump_data(5, req->out.body, req->out.body_size);
 282
 283         /* check if the transport is dead */
 284         if (req->transport->socket->sock == NULL) {
 285                 req->state = SMB2_REQUEST_ERROR;
 286                 req->status = NT_STATUS_NET_WRITE_FAULT;
 287                 return;
 288         }
 289
 290         blob = data_blob_const(req->out.buffer, req->out.size);
 291         status = packet_send(req->transport->packet, blob);
 292         if (!NT_STATUS_IS_OK(status)) {
 293                 req->state = SMB2_REQUEST_ERROR;
 294                 req->status = status;
 295                 return;
 296         }
 297
 298         req->state = SMB2_REQUEST_RECV;
 299         DLIST_ADD(req->transport->pending_recv, req);
 300
 301         /* add a timeout */
 302         if (req->transport->options.timeout) {
 303                 event_add_timed(req->transport->socket->event.ctx, req,
 304                                 timeval_current_ofs(req->transport->options.timeout, 0),
 305                                 smb2_timeout_handler, req);
 306         }
 307
 308         talloc_set_destructor(req, smb2_request_destructor);
 309 }