source4/smbd/service_stream.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    helper functions for stream based servers
   5
   6    Copyright (C) Andrew Tridgell 2003-2005
   7    Copyright (C) Stefan (metze) Metzmacher      2004
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21 */
  22
  23 #include "includes.h"
  24 #include <tevent.h>
  25 #include "process_model.h"
  26 #include "lib/util/server_id.h"
  27 #include "lib/messaging/irpc.h"
  28 #include "cluster/cluster.h"
  29 #include "param/param.h"
  30 #include "../lib/tsocket/tsocket.h"
  31 #include "lib/util/util_net.h"
  32
  33 /* size of listen() backlog in smbd */
  34 #define SERVER_LISTEN_BACKLOG 10
  35
  36
  37 /*
  38   private structure for a single listening stream socket
  39 */
  40 struct stream_socket {
  41         const struct stream_server_ops *ops;
  42         struct loadparm_context *lp_ctx;
  43         struct tevent_context *event_ctx;
  44         const struct model_ops *model_ops;
  45         struct socket_context *sock;
  46         void *private_data;
  47 };
  48
  49
  50 /*
  51   close the socket and shutdown a stream_connection
  52 */
  53 void stream_terminate_connection(struct stream_connection *srv_conn, const char *reason)
  54 {
  55         struct tevent_context *event_ctx = srv_conn->event.ctx;
  56         const struct model_ops *model_ops = srv_conn->model_ops;
  57         struct loadparm_context *lp_ctx = srv_conn->lp_ctx;
  58
  59         if (!reason) reason = "unknown reason";
  60
  61         if (srv_conn->processing) {
  62                 DEBUG(3,("Terminating connection deferred - '%s'\n", reason));
  63         } else {
  64                 DEBUG(3,("Terminating connection - '%s'\n", reason));
  65         }
  66
  67         srv_conn->terminate = reason;
  68
  69         if (srv_conn->processing) {
  70                 /*
  71                  * if we're currently inside the stream_io_handler(),
  72                  * defer the termination to the end of stream_io_hendler()
  73                  *
  74                  * and we don't want to read or write to the connection...
  75                  */
  76                 tevent_fd_set_flags(srv_conn->event.fde, 0);
  77                 return;
  78         }
  79
  80         talloc_free(srv_conn->event.fde);
  81         srv_conn->event.fde = NULL;
  82         imessaging_cleanup(srv_conn->msg_ctx);
  83         TALLOC_FREE(srv_conn);
  84         model_ops->terminate(event_ctx, lp_ctx, reason);
  85 }
  86
  87 /**
  88   the select loop has indicated that a stream is ready for IO
  89 */
  90 static void stream_io_handler(struct stream_connection *conn, uint16_t flags)
  91 {
  92         conn->processing++;
  93         if (flags & TEVENT_FD_WRITE) {
  94                 conn->ops->send_handler(conn, flags);
  95         } else if (flags & TEVENT_FD_READ) {
  96                 conn->ops->recv_handler(conn, flags);
  97         }
  98         conn->processing--;
  99
 100         if (conn->terminate) {
 101                 stream_terminate_connection(conn, conn->terminate);
 102         }
 103 }
 104
 105 void stream_io_handler_fde(struct tevent_context *ev, struct tevent_fd *fde,
 106                                   uint16_t flags, void *private_data)
 107 {
 108         struct stream_connection *conn = talloc_get_type(private_data,
 109                                                          struct stream_connection);
 110         stream_io_handler(conn, flags);
 111 }
 112
 113 void stream_io_handler_callback(void *private_data, uint16_t flags)
 114 {
 115         struct stream_connection *conn = talloc_get_type(private_data,
 116                                                          struct stream_connection);
 117         stream_io_handler(conn, flags);
 118 }
 119
 120 /*
 121   this creates a stream_connection from an already existing connection,
 122   used for protocols, where a client connection needs to switched into
 123   a server connection
 124 */
 125 NTSTATUS stream_new_connection_merge(struct tevent_context *ev,
 126                                      struct loadparm_context *lp_ctx,
 127                                      const struct model_ops *model_ops,
 128                                      const struct stream_server_ops *stream_ops,
 129                                      struct imessaging_context *msg_ctx,
 130                                      void *private_data,
 131                                      struct stream_connection **_srv_conn)
 132 {
 133         struct stream_connection *srv_conn;
 134
 135         srv_conn = talloc_zero(ev, struct stream_connection);
 136         NT_STATUS_HAVE_NO_MEMORY(srv_conn);
 137
 138         srv_conn->private_data  = private_data;
 139         srv_conn->model_ops     = model_ops;
 140         srv_conn->socket        = NULL;
 141         srv_conn->server_id     = cluster_id(0, 0);
 142         srv_conn->ops           = stream_ops;
 143         srv_conn->msg_ctx       = msg_ctx;
 144         srv_conn->event.ctx     = ev;
 145         srv_conn->lp_ctx        = lp_ctx;
 146         srv_conn->event.fde     = NULL;
 147
 148         *_srv_conn = srv_conn;
 149         return NT_STATUS_OK;
 150 }
 151
 152 /*
 153   called when a new socket connection has been established. This is called in the process
 154   context of the new process (if appropriate)
 155 */
 156 static void stream_new_connection(struct tevent_context *ev,
 157                                   struct loadparm_context *lp_ctx,
 158                                   struct socket_context *sock,
 159                                   struct server_id server_id, void *private_data)
 160 {
 161         struct stream_socket *stream_socket = talloc_get_type(private_data, struct stream_socket);
 162         struct stream_connection *srv_conn;
 163
 164         srv_conn = talloc_zero(ev, struct stream_connection);
 165         if (!srv_conn) {
 166                 DEBUG(0,("talloc(mem_ctx, struct stream_connection) failed\n"));
 167                 return;
 168         }
 169
 170         talloc_steal(srv_conn, sock);
 171
 172         srv_conn->private_data  = stream_socket->private_data;
 173         srv_conn->model_ops     = stream_socket->model_ops;
 174         srv_conn->socket        = sock;
 175         srv_conn->server_id     = server_id;
 176         srv_conn->ops           = stream_socket->ops;
 177         srv_conn->event.ctx     = ev;
 178         srv_conn->lp_ctx        = lp_ctx;
 179
 180         if (!socket_check_access(sock, "smbd", lpcfg_hosts_allow(NULL, lpcfg_default_service(lp_ctx)), lpcfg_hosts_deny(NULL, lpcfg_default_service(lp_ctx)))) {
 181                 stream_terminate_connection(srv_conn, "denied by access rules");
 182                 return;
 183         }
 184
 185         srv_conn->event.fde     = tevent_add_fd(ev, srv_conn, socket_get_fd(sock),
 186                                                 0, stream_io_handler_fde, srv_conn);
 187         if (!srv_conn->event.fde) {
 188                 stream_terminate_connection(srv_conn, "tevent_add_fd() failed");
 189                 return;
 190         }
 191
 192         /* setup to receive internal messages on this connection */
 193         srv_conn->msg_ctx = imessaging_init(srv_conn,
 194                                             lp_ctx,
 195                                             srv_conn->server_id, ev);
 196         if (!srv_conn->msg_ctx) {
 197                 stream_terminate_connection(srv_conn, "imessaging_init() failed");
 198                 return;
 199         }
 200
 201         srv_conn->remote_address = socket_get_remote_addr(srv_conn->socket, srv_conn);
 202         if (!srv_conn->remote_address) {
 203                 stream_terminate_connection(srv_conn, "socket_get_remote_addr() failed");
 204                 return;
 205         }
 206
 207         srv_conn->local_address = socket_get_local_addr(srv_conn->socket, srv_conn);
 208         if (!srv_conn->local_address) {
 209                 stream_terminate_connection(srv_conn, "socket_get_local_addr() failed");
 210                 return;
 211         }
 212
 213         {
 214                 TALLOC_CTX *tmp_ctx;
 215                 const char *title;
 216                 struct server_id_buf idbuf;
 217
 218                 tmp_ctx = talloc_new(srv_conn);
 219
 220                 title = talloc_asprintf(tmp_ctx, "conn[%s] c[%s] s[%s] server_id[%s]",
 221                                         stream_socket->ops->name,
 222                                         tsocket_address_string(srv_conn->remote_address, tmp_ctx),
 223                                         tsocket_address_string(srv_conn->local_address, tmp_ctx),
 224                                         server_id_str_buf(server_id, &idbuf));
 225                 if (title) {
 226                         stream_connection_set_title(srv_conn, title);
 227                 }
 228                 talloc_free(tmp_ctx);
 229         }
 230
 231         /* we're now ready to start receiving events on this stream */
 232         TEVENT_FD_READABLE(srv_conn->event.fde);
 233
 234         /* call the server specific accept code */
 235         stream_socket->ops->accept_connection(srv_conn);
 236 }
 237
 238
 239 /*
 240   called when someone opens a connection to one of our listening ports
 241 */
 242 static void stream_accept_handler(struct tevent_context *ev, struct tevent_fd *fde,
 243                                   uint16_t flags, void *private_data)
 244 {
 245         struct stream_socket *stream_socket = talloc_get_type(private_data, struct stream_socket);
 246
 247         /* ask the process model to create us a process for this new
 248            connection.  When done, it calls stream_new_connection()
 249            with the newly created socket */
 250         stream_socket->model_ops->accept_connection(ev, stream_socket->lp_ctx,
 251                                                     stream_socket->sock,
 252                                                     stream_new_connection, stream_socket);
 253 }
 254
 255 /*
 256   setup a listen stream socket
 257   if you pass *port == 0, then a port > 1024 is used
 258
 259   FIXME: This function is TCP/IP specific - uses an int rather than
 260          a string for the port. Should leave allocating a port nr
 261          to the socket implementation - JRV20070903
 262  */
 263 NTSTATUS stream_setup_socket(TALLOC_CTX *mem_ctx,
 264                              struct tevent_context *event_context,
 265                              struct loadparm_context *lp_ctx,
 266                              const struct model_ops *model_ops,
 267                              const struct stream_server_ops *stream_ops,
 268                              const char *family,
 269                              const char *sock_addr,
 270                              uint16_t *port,
 271                              const char *socket_options,
 272                              void *private_data)
 273 {
 274         NTSTATUS status;
 275         struct stream_socket *stream_socket;
 276         struct socket_address *socket_address;
 277         struct tevent_fd *fde;
 278         int i;
 279         struct sockaddr_storage ss;
 280
 281         stream_socket = talloc_zero(mem_ctx, struct stream_socket);
 282         NT_STATUS_HAVE_NO_MEMORY(stream_socket);
 283
 284         if (strcmp(family, "ip") == 0) {
 285                 /* we will get the real family from the address itself */
 286                 if (!interpret_string_addr(&ss, sock_addr, 0)) {
 287                         talloc_free(stream_socket);
 288                         return NT_STATUS_INVALID_ADDRESS;
 289                 }
 290
 291                 socket_address = socket_address_from_sockaddr_storage(stream_socket, &ss, port?*port:0);
 292                 if (socket_address == NULL) {
 293                         TALLOC_FREE(stream_socket);
 294                         return NT_STATUS_NO_MEMORY;
 295                 }
 296
 297                 status = socket_create(socket_address->family, SOCKET_TYPE_STREAM, &stream_socket->sock, 0);
 298                 NT_STATUS_NOT_OK_RETURN(status);
 299         } else {
 300                 status = socket_create(family, SOCKET_TYPE_STREAM, &stream_socket->sock, 0);
 301                 NT_STATUS_NOT_OK_RETURN(status);
 302
 303                 /* this is for non-IP sockets, eg. unix domain sockets */
 304                 socket_address = socket_address_from_strings(stream_socket,
 305                                                              stream_socket->sock->backend_name,
 306                                                              sock_addr, port?*port:0);
 307                 NT_STATUS_HAVE_NO_MEMORY(socket_address);
 308         }
 309
 310
 311         talloc_steal(stream_socket, stream_socket->sock);
 312
 313         stream_socket->lp_ctx = talloc_reference(stream_socket, lp_ctx);
 314
 315         /* ready to listen */
 316         status = socket_set_option(stream_socket->sock, "SO_KEEPALIVE", NULL);
 317         NT_STATUS_NOT_OK_RETURN(status);
 318
 319         if (socket_options != NULL) {
 320                 status = socket_set_option(stream_socket->sock, socket_options, NULL);
 321                 NT_STATUS_NOT_OK_RETURN(status);
 322         }
 323
 324         /* TODO: set socket ACL's (host allow etc) here when they're
 325          * implemented */
 326
 327         /* Some sockets don't have a port, or are just described from
 328          * the string.  We are indicating this by having port == NULL */
 329         if (!port) {
 330                 status = socket_listen(stream_socket->sock, socket_address, SERVER_LISTEN_BACKLOG, 0);
 331         } else if (*port == 0) {
 332                 for (i = lpcfg_rpc_low_port(lp_ctx);
 333                      i <= lpcfg_rpc_high_port(lp_ctx);
 334                      i++) {
 335                         socket_address->port = i;
 336                         status = socket_listen(stream_socket->sock, socket_address,
 337                                                SERVER_LISTEN_BACKLOG, 0);
 338                         if (NT_STATUS_IS_OK(status)) {
 339                                 *port = i;
 340                                 break;
 341                         }
 342                 }
 343         } else {
 344                 status = socket_listen(stream_socket->sock, socket_address, SERVER_LISTEN_BACKLOG, 0);
 345         }
 346
 347         if (!NT_STATUS_IS_OK(status)) {
 348                 DEBUG(0,("Failed to listen on %s:%u - %s\n",
 349                          sock_addr, port ? (unsigned int)(*port) : 0,
 350                          nt_errstr(status)));
 351                 talloc_free(stream_socket);
 352                 return status;
 353         }
 354
 355         /* Add the FD from the newly created socket into the event
 356          * subsystem.  it will call the accept handler whenever we get
 357          * new connections */
 358
 359         fde = tevent_add_fd(event_context, stream_socket->sock,
 360                             socket_get_fd(stream_socket->sock),
 361                             TEVENT_FD_READ,
 362                             stream_accept_handler, stream_socket);
 363         if (!fde) {
 364                 DEBUG(0,("Failed to setup fd event\n"));
 365                 talloc_free(stream_socket);
 366                 return NT_STATUS_NO_MEMORY;
 367         }
 368
 369         /* we let events system to the close on the socket. This avoids
 370          * nasty interactions with waiting for talloc to close the socket. */
 371         tevent_fd_set_close_fn(fde, socket_tevent_fd_close_fn);
 372         socket_set_flags(stream_socket->sock, SOCKET_FLAG_NOCLOSE);
 373
 374         stream_socket->private_data     = talloc_reference(stream_socket, private_data);
 375         stream_socket->ops              = stream_ops;
 376         stream_socket->event_ctx        = event_context;
 377         stream_socket->model_ops        = model_ops;
 378
 379         return NT_STATUS_OK;
 380 }
 381
 382
 383 /*
 384   setup a connection title
 385 */
 386 void stream_connection_set_title(struct stream_connection *conn, const char *title)
 387 {
 388         conn->model_ops->set_title(conn->event.ctx, title);
 389 }