source4/smbd/process_single.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    process model: process (1 process handles all client connections)
   5
   6    Copyright (C) Andrew Tridgell 2003
   7    Copyright (C) James J Myers 2003 <myersjj@samba.org>
   8    Copyright (C) Stefan (metze) Metzmacher 2004
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 3 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  22 */
  23
  24 #include "includes.h"
  25 #include "smbd/process_model.h"
  26 #include "system/filesys.h"
  27 #include "cluster/cluster.h"
  28
  29 /*
  30   called when the process model is selected
  31 */
  32 static void single_model_init(void)
  33 {
  34 }
  35
  36 /*
  37   called when a listening socket becomes readable.
  38 */
  39 static void single_accept_connection(struct tevent_context *ev,
  40                                      struct loadparm_context *lp_ctx,
  41                                      struct socket_context *listen_socket,
  42                                      void (*new_conn)(struct tevent_context *,
  43                                                       struct loadparm_context *,
  44                                                       struct socket_context *,
  45                                                       struct server_id , void *),
  46                                      void *private_data)
  47 {
  48         NTSTATUS status;
  49         struct socket_context *connected_socket;
  50
  51         /* accept an incoming connection. */
  52         status = socket_accept(listen_socket, &connected_socket);
  53         if (!NT_STATUS_IS_OK(status)) {
  54                 DEBUG(0,("single_accept_connection: accept: %s\n", nt_errstr(status)));
  55                 /* this looks strange, but is correct.
  56
  57                    We can only be here if woken up from select, due to
  58                    an incoming connection.
  59
  60                    We need to throttle things until the system clears
  61                    enough resources to handle this new socket.
  62
  63                    If we don't then we will spin filling the log and
  64                    causing more problems. We don't panic as this is
  65                    probably a temporary resource constraint */
  66                 sleep(1);
  67                 return;
  68         }
  69
  70         talloc_steal(private_data, connected_socket);
  71
  72         /* The cluster_id(0, fd) cannot collide with the incrementing
  73          * task below, as the first component is 0, not 1 */
  74         new_conn(ev, lp_ctx, connected_socket,
  75                  cluster_id(0, socket_get_fd(connected_socket)), private_data);
  76 }
  77
  78 /*
  79   called to startup a new task
  80 */
  81 static void single_new_task(struct tevent_context *ev,
  82                             struct loadparm_context *lp_ctx,
  83                             const char *service_name,
  84                             void (*new_task)(struct tevent_context *, struct loadparm_context *, struct server_id, void *),
  85                             void *private_data)
  86 {
  87         /* start our taskids at 1, zero is reserved for the top
  88            level samba task */
  89         static uint32_t taskid = 1;
  90
  91         /* We use 1 so we cannot collide in with cluster ids generated
  92          * in the accept connection above, and unlikly to collide with
  93          * PIDs from process modal standard (don't run samba as
  94          * init) */
  95         new_task(ev, lp_ctx, cluster_id(1, taskid++), private_data);
  96 }
  97
  98
  99 /* called when a task goes down */
 100 static void single_terminate(struct tevent_context *ev, struct loadparm_context *lp_ctx, const char *reason)
 101 {
 102         DEBUG(3,("single_terminate: reason[%s]\n",reason));
 103 }
 104
 105 /* called to set a title of a task or connection */
 106 static void single_set_title(struct tevent_context *ev, const char *title)
 107 {
 108 }
 109
 110 const struct model_ops single_ops = {
 111         .name                   = "single",
 112         .model_init             = single_model_init,
 113         .new_task               = single_new_task,
 114         .accept_connection      = single_accept_connection,
 115         .terminate              = single_terminate,
 116         .set_title              = single_set_title,
 117 };
 118
 119 /*
 120   initialise the single process model, registering ourselves with the
 121   process model subsystem
 122  */
 123 NTSTATUS process_model_single_init(void)
 124 {
 125         return register_process_model(&single_ops);
 126 }