source4/samba/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 "samba/process_model.h"
  26 #include "system/filesys.h"
  27 #include "cluster/cluster.h"
  28
  29 NTSTATUS process_model_single_init(TALLOC_CTX *);
  30
  31 /*
  32   called when the process model is selected
  33 */
  34 static void single_model_init(void)
  35 {
  36 }
  37
  38 /*
  39   called when a listening socket becomes readable.
  40 */
  41 static void single_accept_connection(struct tevent_context *ev,
  42                                      struct loadparm_context *lp_ctx,
  43                                      struct socket_context *listen_socket,
  44                                      void (*new_conn)(struct tevent_context *,
  45                                                       struct loadparm_context *,
  46                                                       struct socket_context *,
  47                                                       struct server_id, void *,
  48                                                       void *),
  49                                      void *private_data,
  50                                      void *process_context)
  51 {
  52         NTSTATUS status;
  53         struct socket_context *connected_socket;
  54         pid_t pid = getpid();
  55
  56         /* accept an incoming connection. */
  57         status = socket_accept(listen_socket, &connected_socket);
  58         if (!NT_STATUS_IS_OK(status)) {
  59                 DBG_ERR("single_accept_connection: accept: %s\n",
  60                         nt_errstr(status));
  61                 /* this looks strange, but is correct.
  62
  63                    We can only be here if woken up from select, due to
  64                    an incoming connection.
  65
  66                    We need to throttle things until the system clears
  67                    enough resources to handle this new socket.
  68
  69                    If we don't then we will spin filling the log and
  70                    causing more problems. We don't panic as this is
  71                    probably a temporary resource constraint */
  72                 sleep(1);
  73                 return;
  74         }
  75
  76         talloc_steal(private_data, connected_socket);
  77
  78         /*
  79          * We use the PID so we cannot collide in with cluster ids
  80          * generated in other single mode tasks, and, and won't
  81          * collide with PIDs from process model standard because a the
  82          * combination of pid/fd should be unique system-wide
  83          */
  84         new_conn(ev, lp_ctx, connected_socket,
  85                  cluster_id(pid, socket_get_fd(connected_socket)), private_data,
  86                             process_context);
  87 }
  88
  89 /*
  90   called to startup a new task
  91 */
  92 static void single_new_task(struct tevent_context *ev,
  93                             struct loadparm_context *lp_ctx,
  94                             const char *service_name,
  95                             struct task_server *(*new_task)(struct tevent_context *,
  96                                              struct loadparm_context *,
  97                                              struct server_id, void *, void *),
  98                             void *private_data,
  99                             const struct service_details *service_details,
 100                             int from_parent_fd)
 101 {
 102         pid_t pid = getpid();
 103         /* start our taskids at MAX_INT32, the first 2^31 tasks are is reserved for fd numbers */
 104         static uint32_t taskid = INT32_MAX;
 105         struct task_server *task = NULL;
 106         /*
 107          * We use the PID so we cannot collide in with cluster ids
 108          * generated in other single mode tasks, and, and won't
 109          * collide with PIDs from process model starndard because a the
 110          * combination of pid/task_id should be unique system-wide
 111          *
 112          * Using the pid unaltered makes debugging of which process
 113          * owns the messaging socket easier.
 114          */
 115         task = new_task(ev, lp_ctx, cluster_id(pid, taskid++), private_data, NULL);
 116         if (task != NULL && service_details->post_fork != NULL) {
 117                 struct process_details pd = initial_process_details;
 118                 service_details->post_fork(task, &pd);
 119         }
 120 }
 121
 122 /*
 123  * Called when a task goes down
 124  */
 125 static void single_terminate_task(struct tevent_context *ev,
 126                                   struct loadparm_context *lp_ctx,
 127                                   const char *reason,
 128                                   bool fatal,
 129                                   void *process_context)
 130 {
 131         DBG_NOTICE("single_terminate: reason[%s]\n",reason);
 132 }
 133
 134 /*
 135  * Called when a connection has ended
 136  */
 137 static void single_terminate_connection(struct tevent_context *ev,
 138                                         struct loadparm_context *lp_ctx,
 139                                         const char *reason,
 140                                         void *process_context)
 141 {
 142 }
 143
 144 /* called to set a title of a task or connection */
 145 static void single_set_title(struct tevent_context *ev, const char *title)
 146 {
 147 }
 148
 149 const struct model_ops single_ops = {
 150         .name                   = "single",
 151         .model_init             = single_model_init,
 152         .new_task               = single_new_task,
 153         .accept_connection      = single_accept_connection,
 154         .terminate_task         = single_terminate_task,
 155         .terminate_connection   = single_terminate_connection,
 156         .set_title              = single_set_title,
 157 };
 158
 159 /*
 160   initialise the single process model, registering ourselves with the
 161   process model subsystem
 162  */
 163 NTSTATUS process_model_single_init(TALLOC_CTX *ctx)
 164 {
 165         return register_process_model(&single_ops);
 166 }