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 2 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, write to the Free Software
  21    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22 */
  23
  24 #include "includes.h"
  25 #include "process_model.h"
  26 #include "lib/events/events.h"
  27 #include "lib/socket/socket.h"
  28 #include "smbd/service.h"
  29 #include "smbd/service_stream.h"
  30 #include "lib/messaging/irpc.h"
  31 #include "cluster/cluster.h"
  32
  33 /* the range of ports to try for dcerpc over tcp endpoints */
  34 #define SERVER_TCP_LOW_PORT  1024
  35 #define SERVER_TCP_HIGH_PORT 1300
  36
  37 /* size of listen() backlog in smbd */
  38 #define SERVER_LISTEN_BACKLOG 10
  39
  40
  41 /*
  42   private structure for a single listening stream socket
  43 */
  44 struct stream_socket {
  45         const struct stream_server_ops *ops;
  46         struct event_context *event_ctx;
  47         const struct model_ops *model_ops;
  48         struct socket_context *sock;
  49         void *private;
  50 };
  51
  52
  53 /*
  54   close the socket and shutdown a stream_connection
  55 */
  56 void stream_terminate_connection(struct stream_connection *srv_conn, const char *reason)
  57 {
  58         struct event_context *event_ctx = srv_conn->event.ctx;
  59         const struct model_ops *model_ops = srv_conn->model_ops;
  60
  61         if (!reason) reason = "unknown reason";
  62
  63         srv_conn->terminate = reason;
  64
  65         if (srv_conn->processing) {
  66                 /*
  67                  * if we're currently inside the stream_io_handler(),
  68                  * defer the termination to the end of stream_io_hendler()
  69                  *
  70                  * and we don't want to read or write to the connection...
  71                  */
  72                 event_set_fd_flags(srv_conn->event.fde, 0);
  73                 return;
  74         }
  75
  76         talloc_free(srv_conn->event.fde);
  77         srv_conn->event.fde = NULL;
  78         talloc_free(srv_conn);
  79         model_ops->terminate(event_ctx, reason);
  80 }
  81
  82 /*
  83   the select loop has indicated that a stream is ready for IO
  84 */
  85 static void stream_io_handler(struct stream_connection *conn, uint16_t flags)
  86 {
  87         conn->processing = True;
  88         if (flags & EVENT_FD_WRITE) {
  89                 conn->ops->send_handler(conn, flags);
  90         } else if (flags & EVENT_FD_READ) {
  91                 conn->ops->recv_handler(conn, flags);
  92         }
  93         conn->processing = False;
  94
  95         if (conn->terminate) {
  96                 stream_terminate_connection(conn, conn->terminate);
  97         }
  98 }
  99
 100 static void stream_io_handler_fde(struct event_context *ev, struct fd_event *fde,
 101                                   uint16_t flags, void *private)
 102 {
 103         struct stream_connection *conn = talloc_get_type(private,
 104                                                          struct stream_connection);
 105         stream_io_handler(conn, flags);
 106 }
 107
 108 void stream_io_handler_callback(void *private, uint16_t flags)
 109 {
 110         struct stream_connection *conn = talloc_get_type(private,
 111                                                          struct stream_connection);
 112         stream_io_handler(conn, flags);
 113 }
 114
 115 /*
 116   this creates a stream_connection from an already existing connection,
 117   used for protocols, where a client connection needs to switched into
 118   a server connection
 119 */
 120 NTSTATUS stream_new_connection_merge(struct event_context *ev,
 121                                      const struct model_ops *model_ops,
 122                                      struct socket_context *sock,
 123                                      const struct stream_server_ops *stream_ops,
 124                                      struct messaging_context *msg_ctx,
 125                                      void *private_data,
 126                                      struct stream_connection **_srv_conn)
 127 {
 128         struct stream_connection *srv_conn;
 129
 130         srv_conn = talloc_zero(ev, struct stream_connection);
 131         NT_STATUS_HAVE_NO_MEMORY(srv_conn);
 132
 133         talloc_steal(srv_conn, sock);
 134
 135         srv_conn->private       = private_data;
 136         srv_conn->model_ops     = model_ops;
 137         srv_conn->socket        = sock;
 138         srv_conn->server_id     = cluster_id(0);
 139         srv_conn->ops           = stream_ops;
 140         srv_conn->msg_ctx       = msg_ctx;
 141         srv_conn->event.ctx     = ev;
 142         srv_conn->event.fde     = event_add_fd(ev, srv_conn, socket_get_fd(sock),
 143                                                EVENT_FD_READ,
 144                                                stream_io_handler_fde, srv_conn);
 145         *_srv_conn = srv_conn;
 146         return NT_STATUS_OK;
 147 }
 148
 149 /*
 150   called when a new socket connection has been established. This is called in the process
 151   context of the new process (if appropriate)
 152 */
 153 static void stream_new_connection(struct event_context *ev,
 154                                   struct socket_context *sock,
 155                                   struct server_id server_id, void *private)
 156 {
 157         struct stream_socket *stream_socket = talloc_get_type(private, struct stream_socket);
 158         struct stream_connection *srv_conn;
 159         struct socket_address *c, *s;
 160
 161         srv_conn = talloc_zero(ev, struct stream_connection);
 162         if (!srv_conn) {
 163                 DEBUG(0,("talloc(mem_ctx, struct stream_connection) failed\n"));
 164                 return;
 165         }
 166
 167         talloc_steal(srv_conn, sock);
 168
 169         srv_conn->private       = stream_socket->private;
 170         srv_conn->model_ops     = stream_socket->model_ops;
 171         srv_conn->socket        = sock;
 172         srv_conn->server_id     = server_id;
 173         srv_conn->ops           = stream_socket->ops;
 174         srv_conn->event.ctx     = ev;
 175         srv_conn->event.fde     = event_add_fd(ev, srv_conn, socket_get_fd(sock),
 176                                                EVENT_FD_READ,
 177                                                stream_io_handler_fde, srv_conn);
 178
 179         if (!socket_check_access(sock, "smbd", lp_hostsallow(-1), lp_hostsdeny(-1))) {
 180                 stream_terminate_connection(srv_conn, "denied by access rules");
 181                 return;
 182         }
 183
 184         /* setup to receive internal messages on this connection */
 185         srv_conn->msg_ctx = messaging_init(srv_conn, srv_conn->server_id, ev);
 186         if (!srv_conn->msg_ctx) {
 187                 stream_terminate_connection(srv_conn, "messaging_init() failed");
 188                 return;
 189         }
 190
 191         c = socket_get_peer_addr(sock, ev);
 192         s = socket_get_my_addr(sock, ev);
 193         if (s && c) {
 194                 const char *title;
 195                 title = talloc_asprintf(s, "conn[%s] c[%s:%u] s[%s:%u] server_id[%s]",
 196                                         stream_socket->ops->name,
 197                                         c->addr, c->port, s->addr, s->port,
 198                                         cluster_id_string(s, server_id));
 199                 if (title) {
 200                         stream_connection_set_title(srv_conn, title);
 201                 }
 202         }
 203         talloc_free(c);
 204         talloc_free(s);
 205
 206         /* call the server specific accept code */
 207         stream_socket->ops->accept_connection(srv_conn);
 208 }
 209
 210
 211 /*
 212   called when someone opens a connection to one of our listening ports
 213 */
 214 static void stream_accept_handler(struct event_context *ev, struct fd_event *fde,
 215                                   uint16_t flags, void *private)
 216 {
 217         struct stream_socket *stream_socket = talloc_get_type(private, struct stream_socket);
 218
 219         /* ask the process model to create us a process for this new
 220            connection.  When done, it calls stream_new_connection()
 221            with the newly created socket */
 222         stream_socket->model_ops->accept_connection(ev, stream_socket->sock,
 223                                                     stream_new_connection, stream_socket);
 224 }
 225
 226
 227
 228 /*
 229   setup a listen stream socket
 230   if you pass *port == 0, then a port > 1024 is used
 231  */
 232 NTSTATUS stream_setup_socket(struct event_context *event_context,
 233                              const struct model_ops *model_ops,
 234                              const struct stream_server_ops *stream_ops,
 235                              const char *family,
 236                              const char *sock_addr,
 237                              uint16_t *port,
 238                              void *private)
 239 {
 240         NTSTATUS status;
 241         struct stream_socket *stream_socket;
 242         struct socket_address *socket_address;
 243         int i;
 244
 245         stream_socket = talloc_zero(event_context, struct stream_socket);
 246         NT_STATUS_HAVE_NO_MEMORY(stream_socket);
 247
 248         status = socket_create(family, SOCKET_TYPE_STREAM, &stream_socket->sock, 0);
 249         NT_STATUS_NOT_OK_RETURN(status);
 250
 251         talloc_steal(stream_socket, stream_socket->sock);
 252
 253         /* ready to listen */
 254         status = socket_set_option(stream_socket->sock, "SO_KEEPALIVE", NULL);
 255         NT_STATUS_NOT_OK_RETURN(status);
 256
 257         status = socket_set_option(stream_socket->sock, lp_socket_options(), NULL);
 258         NT_STATUS_NOT_OK_RETURN(status);
 259
 260         /* TODO: set socket ACL's here when they're implemented */
 261
 262         if (*port == 0) {
 263                 for (i=SERVER_TCP_LOW_PORT;i<= SERVER_TCP_HIGH_PORT;i++) {
 264                         socket_address = socket_address_from_strings(stream_socket,
 265                                                                      stream_socket->sock->backend_name,
 266                                                                      sock_addr, i);
 267                         NT_STATUS_HAVE_NO_MEMORY(socket_address);
 268                         status = socket_listen(stream_socket->sock, socket_address,
 269                                                SERVER_LISTEN_BACKLOG, 0);
 270                         talloc_free(socket_address);
 271                         if (NT_STATUS_IS_OK(status)) {
 272                                 *port = i;
 273                                 break;
 274                         }
 275                 }
 276         } else {
 277                 socket_address = socket_address_from_strings(stream_socket,
 278                                                              stream_socket->sock->backend_name,
 279                                                              sock_addr, *port);
 280                 NT_STATUS_HAVE_NO_MEMORY(socket_address);
 281                 status = socket_listen(stream_socket->sock, socket_address, SERVER_LISTEN_BACKLOG, 0);
 282                 talloc_free(socket_address);
 283         }
 284
 285         if (!NT_STATUS_IS_OK(status)) {
 286                 DEBUG(0,("Failed to listen on %s:%u - %s\n",
 287                         sock_addr, *port, nt_errstr(status)));
 288                 talloc_free(stream_socket);
 289                 return status;
 290         }
 291
 292         event_add_fd(event_context, stream_socket->sock,
 293                      socket_get_fd(stream_socket->sock),
 294                      EVENT_FD_READ, stream_accept_handler, stream_socket);
 295
 296         stream_socket->private          = talloc_reference(stream_socket, private);
 297         stream_socket->ops              = stream_ops;
 298         stream_socket->event_ctx        = event_context;
 299         stream_socket->model_ops        = model_ops;
 300
 301         return NT_STATUS_OK;
 302 }
 303
 304 /*
 305   setup a connection title
 306 */
 307 void stream_connection_set_title(struct stream_connection *conn, const char *title)
 308 {
 309         conn->model_ops->set_title(conn->event.ctx, title);
 310 }