source/wrepl_server/wrepl_in_connection.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    WINS Replication server
   5
   6    Copyright (C) Stefan Metzmacher      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 "dlinklist.h"
  25 #include "lib/events/events.h"
  26 #include "lib/socket/socket.h"
  27 #include "smbd/service_task.h"
  28 #include "smbd/service_stream.h"
  29 #include "lib/messaging/irpc.h"
  30 #include "librpc/gen_ndr/ndr_winsrepl.h"
  31 #include "wrepl_server/wrepl_server.h"
  32 #include "nbt_server/wins/winsdb.h"
  33 #include "ldb/include/ldb.h"
  34
  35 static void wreplsrv_terminate_in_connection(struct wreplsrv_in_connection *wreplconn, const char *reason)
  36 {
  37         stream_terminate_connection(wreplconn->conn, reason);
  38 }
  39
  40 /*
  41   called when we get a new connection
  42 */
  43 static void wreplsrv_accept(struct stream_connection *conn)
  44 {
  45         struct wreplsrv_service *service = talloc_get_type(conn->private, struct wreplsrv_service);
  46         struct wreplsrv_in_connection *wreplconn;
  47         const char *peer_ip;
  48
  49         wreplconn = talloc_zero(conn, struct wreplsrv_in_connection);
  50         if (!wreplconn) {
  51                 stream_terminate_connection(conn, "wreplsrv_accept: out of memory");
  52                 return;
  53         }
  54
  55         wreplconn->conn         = conn;
  56         wreplconn->service      = service;
  57         wreplconn->our_ip       = socket_get_my_addr(conn->socket, wreplconn);
  58         if (!wreplconn->our_ip) {
  59                 wreplsrv_terminate_in_connection(wreplconn, "wreplsrv_accept: out of memory");
  60                 return;
  61         }
  62
  63         peer_ip = socket_get_peer_addr(conn->socket, wreplconn);
  64         if (!peer_ip) {
  65                 wreplsrv_terminate_in_connection(wreplconn, "wreplsrv_accept: out of memory");
  66                 return;
  67         }
  68
  69         wreplconn->partner      = wreplsrv_find_partner(service, peer_ip);
  70
  71         conn->private = wreplconn;
  72
  73         irpc_add_name(conn->msg_ctx, "wreplsrv_connection");
  74 }
  75
  76 /*
  77   receive some data on a WREPL connection
  78 */
  79 static void wreplsrv_recv(struct stream_connection *conn, uint16_t flags)
  80 {
  81         struct wreplsrv_in_connection *wreplconn = talloc_get_type(conn->private, struct wreplsrv_in_connection);
  82         struct wreplsrv_in_call *call;
  83         DATA_BLOB packet_in_blob;
  84         DATA_BLOB packet_out_blob;
  85         struct wrepl_wrap packet_out_wrap;
  86         struct data_blob_list_item *rep;
  87         NTSTATUS status = NT_STATUS_UNSUCCESSFUL;
  88         size_t nread;
  89
  90         /* avoid recursion, because of half async code */
  91         if (wreplconn->processing) {
  92                 EVENT_FD_NOT_READABLE(conn->event.fde);
  93                 return;
  94         }
  95
  96         if (wreplconn->partial.length == 0) {
  97                 wreplconn->partial = data_blob_talloc(wreplconn, NULL, 4);
  98                 if (wreplconn->partial.data == NULL) {
  99                         status = NT_STATUS_NO_MEMORY;
 100                         goto failed;
 101                 }
 102                 wreplconn->partial_read = 0;
 103         }
 104
 105         /* read in the packet length */
 106         if (wreplconn->partial_read < 4) {
 107                 uint32_t packet_length;
 108
 109                 status = socket_recv(conn->socket,
 110                                      wreplconn->partial.data + wreplconn->partial_read,
 111                                      4 - wreplconn->partial_read,
 112                                      &nread, 0);
 113                 if (NT_STATUS_IS_ERR(status)) goto failed;
 114                 if (!NT_STATUS_IS_OK(status)) return;
 115
 116                 wreplconn->partial_read += nread;
 117                 if (wreplconn->partial_read != 4) return;
 118
 119                 packet_length = RIVAL(wreplconn->partial.data, 0) + 4;
 120
 121                 wreplconn->partial.data = talloc_realloc(wreplconn, wreplconn->partial.data,
 122                                                          uint8_t, packet_length);
 123                 if (wreplconn->partial.data == NULL) {
 124                         status = NT_STATUS_NO_MEMORY;
 125                         goto failed;
 126                 }
 127                 wreplconn->partial.length = packet_length;
 128         }
 129
 130         /* read in the body */
 131         status = socket_recv(conn->socket,
 132                              wreplconn->partial.data + wreplconn->partial_read,
 133                              wreplconn->partial.length - wreplconn->partial_read,
 134                              &nread, 0);
 135         if (NT_STATUS_IS_ERR(status)) goto failed;
 136         if (!NT_STATUS_IS_OK(status)) return;
 137
 138         wreplconn->partial_read += nread;
 139         if (wreplconn->partial_read != wreplconn->partial.length) return;
 140
 141         packet_in_blob.data = wreplconn->partial.data + 4;
 142         packet_in_blob.length = wreplconn->partial.length - 4;
 143
 144         call = talloc_zero(wreplconn, struct wreplsrv_in_call);
 145         if (!call) {
 146                 status = NT_STATUS_NO_MEMORY;
 147                 goto failed;
 148         }
 149         call->wreplconn = wreplconn;
 150
 151         /* we have a full request - parse it */
 152         status = ndr_pull_struct_blob(&packet_in_blob,
 153                                       call, &call->req_packet,
 154                                       (ndr_pull_flags_fn_t)ndr_pull_wrepl_packet);
 155         if (!NT_STATUS_IS_OK(status)) {
 156                 DEBUG(2,("Failed to parse incoming WINS-Replication packet - %s\n",
 157                          nt_errstr(status)));
 158                 DEBUG(10,("packet length %u\n", wreplconn->partial.length));
 159                 NDR_PRINT_DEBUG(wrepl_packet, &call->req_packet);
 160                 goto failed;
 161         }
 162
 163         /*
 164          * we have parsed the request, so we can reset the wreplconn->partial_read,
 165          * maybe we could also free wreplconn->partial, but for now we keep it,
 166          * and overwrite it the next time
 167          */
 168         wreplconn->partial_read = 0;
 169
 170         if (DEBUGLVL(10)) {
 171                 DEBUG(10,("Received WINS-Replication packet of length %u\n", wreplconn->partial.length));
 172                 NDR_PRINT_DEBUG(wrepl_packet, &call->req_packet);
 173         }
 174
 175         /* actually process the request */
 176         wreplconn->processing = True;
 177         status = wreplsrv_in_call(call);
 178         wreplconn->processing = False;
 179         if (NT_STATUS_IS_ERR(status)) goto failed;
 180         if (!NT_STATUS_IS_OK(status)) {
 181                 /* w2k just ignores invalid packets, so we do */
 182                 DEBUG(10,("Received WINS-Replication packet was invalid, we just ignore it\n"));
 183                 talloc_free(call);
 184                 return;
 185         }
 186
 187         /* and now encode the reply */
 188         packet_out_wrap.packet = call->rep_packet;
 189         status = ndr_push_struct_blob(&packet_out_blob, call, &packet_out_wrap,
 190                                       (ndr_push_flags_fn_t)ndr_push_wrepl_wrap);
 191         if (!NT_STATUS_IS_OK(status)) goto failed;
 192
 193         if (DEBUGLVL(10)) {
 194                 DEBUG(10,("Sending WINS-Replication packet of length %d\n", (int)packet_out_blob.length));
 195                 NDR_PRINT_DEBUG(wrepl_packet, &call->rep_packet);
 196         }
 197
 198         rep = talloc(wreplconn, struct data_blob_list_item);
 199         if (!rep) {
 200                 status = NT_STATUS_NO_MEMORY;
 201                 goto failed;
 202         }
 203
 204         rep->blob = packet_out_blob;
 205         talloc_steal(rep, packet_out_blob.data);
 206         /* we don't need the call anymore */
 207         talloc_free(call);
 208
 209         if (!wreplconn->send_queue) {
 210                 EVENT_FD_WRITEABLE(conn->event.fde);
 211         }
 212         DLIST_ADD_END(wreplconn->send_queue, rep, struct data_blob_list_item *);
 213
 214         if (wreplconn->terminate) {
 215                 EVENT_FD_NOT_READABLE(conn->event.fde);
 216         } else {
 217                 EVENT_FD_READABLE(conn->event.fde);
 218         }
 219         return;
 220
 221 failed:
 222         wreplsrv_terminate_in_connection(wreplconn, nt_errstr(status));
 223 }
 224
 225 /*
 226   called when we can write to a connection
 227 */
 228 static void wreplsrv_send(struct stream_connection *conn, uint16_t flags)
 229 {
 230         struct wreplsrv_in_connection *wreplconn = talloc_get_type(conn->private, struct wreplsrv_in_connection);
 231         NTSTATUS status;
 232
 233         while (wreplconn->send_queue) {
 234                 struct data_blob_list_item *rep = wreplconn->send_queue;
 235                 size_t sendlen;
 236
 237                 status = socket_send(conn->socket, &rep->blob, &sendlen, 0);
 238                 if (NT_STATUS_IS_ERR(status)) goto failed;
 239                 if (!NT_STATUS_IS_OK(status)) return;
 240
 241                 rep->blob.length -= sendlen;
 242                 rep->blob.data   += sendlen;
 243
 244                 if (rep->blob.length == 0) {
 245                         DLIST_REMOVE(wreplconn->send_queue, rep);
 246                         talloc_free(rep);
 247                 }
 248         }
 249
 250         if (wreplconn->terminate) {
 251                 wreplsrv_terminate_in_connection(wreplconn, "connection terminated after all pending packets are send");
 252                 return;
 253         }
 254
 255         EVENT_FD_NOT_WRITEABLE(conn->event.fde);
 256         return;
 257
 258 failed:
 259         wreplsrv_terminate_in_connection(wreplconn, nt_errstr(status));
 260 }
 261
 262 static const struct stream_server_ops wreplsrv_stream_ops = {
 263         .name                   = "wreplsrv",
 264         .accept_connection      = wreplsrv_accept,
 265         .recv_handler           = wreplsrv_recv,
 266         .send_handler           = wreplsrv_send,
 267 };
 268
 269 /*
 270   startup the wrepl port 42 server sockets
 271 */
 272 NTSTATUS wreplsrv_setup_sockets(struct wreplsrv_service *service)
 273 {
 274         NTSTATUS status;
 275         struct task_server *task = service->task;
 276         const struct model_ops *model_ops;
 277         const char *address;
 278         uint16_t port = WINS_REPLICATION_PORT;
 279
 280         /* within the wrepl task we want to be a single process, so
 281            ask for the single process model ops and pass these to the
 282            stream_setup_socket() call. */
 283         model_ops = process_model_byname("single");
 284         if (!model_ops) {
 285                 DEBUG(0,("Can't find 'single' process model_ops"));
 286                 return NT_STATUS_INTERNAL_ERROR;
 287         }
 288
 289         if (lp_interfaces() && lp_bind_interfaces_only()) {
 290                 int num_interfaces = iface_count();
 291                 int i;
 292
 293                 /* We have been given an interfaces line, and been
 294                    told to only bind to those interfaces. Create a
 295                    socket per interface and bind to only these.
 296                 */
 297                 for(i = 0; i < num_interfaces; i++) {
 298                         address = iface_n_ip(i);
 299                         status = stream_setup_socket(task->event_ctx, model_ops, &wreplsrv_stream_ops,
 300                                                      "ipv4", address, &port, service);
 301                         if (!NT_STATUS_IS_OK(status)) {
 302                                 DEBUG(0,("stream_setup_socket(address=%s,port=%u) failed - %s\n",
 303                                          address, port, nt_errstr(status)));
 304                                 return status;
 305                         }
 306                 }
 307         } else {
 308                 address = lp_socket_address();
 309                 status = stream_setup_socket(task->event_ctx, model_ops, &wreplsrv_stream_ops,
 310                                              "ipv4", address, &port, service);
 311                 if (!NT_STATUS_IS_OK(status)) {
 312                         DEBUG(0,("stream_setup_socket(address=%s,port=%u) failed - %s\n",
 313                                  address, port, nt_errstr(status)));
 314                         return status;
 315                 }
 316         }
 317
 318         return NT_STATUS_OK;
 319 }