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 "lib/socket/socket.h"
  27 #include "lib/events/events.h"
  28 #include "lib/stream/packet.h"
  29 #include "include/dlinklist.h"
  30
  31
  32 /*
  33   an event has happened on the socket
  34 */
  35 static void smb2_transport_event_handler(struct event_context *ev,
  36                                          struct fd_event *fde,
  37                                          uint16_t flags, void *private)
  38 {
  39         struct smb2_transport *transport = talloc_get_type(private,
  40                                                            struct smb2_transport);
  41         if (flags & EVENT_FD_READ) {
  42                 packet_recv(transport->packet);
  43                 return;
  44         }
  45         if (flags & EVENT_FD_WRITE) {
  46                 packet_queue_run(transport->packet);
  47         }
  48 }
  49
  50 /*
  51   destroy a transport
  52  */
  53 static int transport_destructor(void *ptr)
  54 {
  55         struct smb2_transport *transport = ptr;
  56         smb2_transport_dead(transport);
  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);
  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_serialise(transport->packet, transport->socket->event.fde);
 111
 112         talloc_set_destructor(transport, transport_destructor);
 113
 114         transport->options.timeout = 30;
 115
 116         return transport;
 117 }
 118
 119 /*
 120   mark the transport as dead
 121 */
 122 void smb2_transport_dead(struct smb2_transport *transport)
 123 {
 124         smbcli_sock_dead(transport->socket);
 125
 126         /* kill all pending receives */
 127         while (transport->pending_recv) {
 128                 struct smb2_request *req = transport->pending_recv;
 129                 req->state = SMB2_REQUEST_ERROR;
 130                 req->status = NT_STATUS_NET_WRITE_FAULT;
 131                 DLIST_REMOVE(transport->pending_recv, req);
 132                 if (req->async.fn) {
 133                         req->async.fn(req);
 134                 }
 135         }
 136 }
 137
 138 /*
 139   we have a full request in our receive buffer - match it to a pending request
 140   and process
 141  */
 142 static NTSTATUS smb2_transport_finish_recv(void *private, DATA_BLOB blob)
 143 {
 144         struct smb2_transport *transport = talloc_get_type(private,
 145                                                              struct smb2_transport);
 146         uint8_t *buffer, *hdr;
 147         int len;
 148         struct smb2_request *req;
 149         uint64_t seqnum;
 150
 151         buffer = blob.data;
 152         len = blob.length;
 153
 154         hdr = buffer+NBT_HDR_SIZE;
 155
 156         if (len < SMB2_MIN_SIZE) {
 157                 DEBUG(1,("Discarding smb2 reply of size %d\n", len));
 158                 goto error;
 159         }
 160
 161         seqnum = BVAL(hdr, SMB2_HDR_SEQNUM);
 162
 163         /* match the incoming request against the list of pending requests */
 164         for (req=transport->pending_recv; req; req=req->next) {
 165                 if (req->seqnum == seqnum) break;
 166         }
 167
 168         if (!req) {
 169                 DEBUG(1,("Discarding unmatched reply with seqnum 0x%llx op %d\n",
 170                          seqnum, SVAL(hdr, SMB2_HDR_OPCODE)));
 171                 goto error;
 172         }
 173
 174         /* fill in the 'in' portion of the matching request */
 175         req->in.buffer = buffer;
 176         talloc_steal(req, buffer);
 177         req->in.size = len;
 178         req->in.allocated = req->in.size;
 179
 180         req->in.hdr       = hdr;
 181         req->in.body      = hdr+SMB2_HDR_BODY;
 182         req->in.body_size = req->in.size - (SMB2_HDR_BODY+NBT_HDR_SIZE);
 183         req->in.ptr       = req->in.body;
 184         req->status       = NT_STATUS(IVAL(hdr, SMB2_HDR_STATUS));
 185
 186         /* if this request has an async handler then call that to
 187            notify that the reply has been received. This might destroy
 188            the request so it must happen last */
 189         DLIST_REMOVE(transport->pending_recv, req);
 190         req->state = SMB2_REQUEST_DONE;
 191         if (req->async.fn) {
 192                 req->async.fn(req);
 193         }
 194         return NT_STATUS_OK;
 195
 196 error:
 197         if (req) {
 198                 DLIST_REMOVE(transport->pending_recv, req);
 199                 req->state = SMB2_REQUEST_ERROR;
 200         }
 201         dump_data(0, blob.data, blob.length);
 202         data_blob_free(&blob);
 203         return NT_STATUS_UNSUCCESSFUL;
 204 }
 205
 206 /*
 207   handle timeouts of individual smb requests
 208 */
 209 static void smb2_timeout_handler(struct event_context *ev, struct timed_event *te,
 210                                    struct timeval t, void *private)
 211 {
 212         struct smb2_request *req = talloc_get_type(private, struct smb2_request);
 213
 214         if (req->state == SMB2_REQUEST_RECV) {
 215                 DLIST_REMOVE(req->transport->pending_recv, req);
 216         }
 217         req->status = NT_STATUS_IO_TIMEOUT;
 218         req->state = SMB2_REQUEST_ERROR;
 219         if (req->async.fn) {
 220                 req->async.fn(req);
 221         }
 222 }
 223
 224
 225 /*
 226   destroy a request
 227 */
 228 static int smb2_request_destructor(void *ptr)
 229 {
 230         struct smb2_request *req = talloc_get_type(ptr, struct smb2_request);
 231         if (req->state == SMB2_REQUEST_RECV) {
 232                 DLIST_REMOVE(req->transport->pending_recv, req);
 233         }
 234         return 0;
 235 }
 236
 237
 238 /*
 239   put a request into the send queue
 240 */
 241 void smb2_transport_send(struct smb2_request *req)
 242 {
 243         DATA_BLOB blob;
 244         NTSTATUS status;
 245
 246         _smb_setlen(req->out.buffer, req->out.size - NBT_HDR_SIZE);
 247
 248         /* check if the transport is dead */
 249         if (req->transport->socket->sock == NULL) {
 250                 req->state = SMB2_REQUEST_ERROR;
 251                 req->status = NT_STATUS_NET_WRITE_FAULT;
 252                 return;
 253         }
 254
 255         blob = data_blob_const(req->out.buffer, req->out.size);
 256         status = packet_send(req->transport->packet, blob);
 257         if (!NT_STATUS_IS_OK(status)) {
 258                 req->state = SMB2_REQUEST_ERROR;
 259                 req->status = status;
 260                 return;
 261         }
 262
 263         req->state = SMB2_REQUEST_RECV;
 264         DLIST_ADD(req->transport->pending_recv, req);
 265
 266         /* add a timeout */
 267         if (req->transport->options.timeout) {
 268                 event_add_timed(req->transport->socket->event.ctx, req,
 269                                 timeval_current_ofs(req->transport->options.timeout, 0),
 270                                 smb2_timeout_handler, req);
 271         }
 272
 273         talloc_set_destructor(req, smb2_request_destructor);
 274 }