source4/libcli/composite/composite.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    Copyright (C) Volker Lendecke 2005
   5    Copyright (C) Andrew Tridgell 2005
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20 /*
  21   composite API helper functions
  22 */
  23
  24 #include "includes.h"
  25 #include "lib/events/events.h"
  26 #include "libcli/raw/libcliraw.h"
  27 #include "libcli/smb2/smb2.h"
  28 #include "libcli/composite/composite.h"
  29 #include "../libcli/nbt/libnbt.h"
  30
  31 /*
  32  create a new composite_context structure
  33  and initialize it
  34 */
  35 _PUBLIC_ struct composite_context *composite_create(TALLOC_CTX *mem_ctx,
  36                                                     struct tevent_context *ev)
  37 {
  38         struct composite_context *c;
  39
  40         c = talloc_zero(mem_ctx, struct composite_context);
  41         if (!c) return NULL;
  42         c->state = COMPOSITE_STATE_IN_PROGRESS;
  43         c->event_ctx = ev;
  44
  45         return c;
  46 }
  47
  48 /*
  49   block until a composite function has completed, then return the status
  50 */
  51 _PUBLIC_ NTSTATUS composite_wait(struct composite_context *c)
  52 {
  53         if (c == NULL) return NT_STATUS_NO_MEMORY;
  54
  55         c->used_wait = true;
  56
  57         while (c->state < COMPOSITE_STATE_DONE) {
  58                 if (tevent_loop_once(c->event_ctx) != 0) {
  59                         return NT_STATUS_UNSUCCESSFUL;
  60                 }
  61         }
  62
  63         return c->status;
  64 }
  65
  66 /*
  67   block until a composite function has completed, then return the status.
  68   Free the composite context before returning
  69 */
  70 _PUBLIC_ NTSTATUS composite_wait_free(struct composite_context *c)
  71 {
  72         NTSTATUS status = composite_wait(c);
  73         talloc_free(c);
  74         return status;
  75 }
  76
  77 /*
  78    callback from composite_done() and composite_error()
  79
  80    this is used to allow for a composite function to complete without
  81    going through any state transitions. When that happens the caller
  82    has had no opportunity to fill in the async callback fields
  83    (ctx->async.fn and ctx->async.private_data) which means the usual way of
  84    dealing with composite functions doesn't work. To cope with this,
  85    we trigger a timer event that will happen then the event loop is
  86    re-entered. This gives the caller a chance to setup the callback,
  87    and allows the caller to ignore the fact that the composite
  88    function completed early
  89 */
  90 static void composite_trigger(struct tevent_context *ev, struct tevent_timer *te,
  91                               struct timeval t, void *ptr)
  92 {
  93         struct composite_context *c = talloc_get_type(ptr, struct composite_context);
  94         if (c->async.fn) {
  95                 c->async.fn(c);
  96         }
  97 }
  98
  99
 100 _PUBLIC_ void composite_error(struct composite_context *ctx, NTSTATUS status)
 101 {
 102         /* you are allowed to pass NT_STATUS_OK to composite_error(), in which
 103            case it is equivalent to composite_done() */
 104         if (NT_STATUS_IS_OK(status)) {
 105                 composite_done(ctx);
 106                 return;
 107         }
 108         if (!ctx->used_wait && !ctx->async.fn) {
 109                 tevent_add_timer(ctx->event_ctx, ctx, timeval_zero(), composite_trigger, ctx);
 110         }
 111         ctx->status = status;
 112         ctx->state = COMPOSITE_STATE_ERROR;
 113         if (ctx->async.fn != NULL) {
 114                 ctx->async.fn(ctx);
 115         }
 116 }
 117
 118 _PUBLIC_ bool composite_nomem(const void *p, struct composite_context *ctx)
 119 {
 120         if (p != NULL) {
 121                 return false;
 122         }
 123         composite_error(ctx, NT_STATUS_NO_MEMORY);
 124         return true;
 125 }
 126
 127 _PUBLIC_ bool composite_is_ok(struct composite_context *ctx)
 128 {
 129         if (NT_STATUS_IS_OK(ctx->status)) {
 130                 return true;
 131         }
 132         composite_error(ctx, ctx->status);
 133         return false;
 134 }
 135
 136 _PUBLIC_ void composite_done(struct composite_context *ctx)
 137 {
 138         if (!ctx->used_wait && !ctx->async.fn) {
 139                 tevent_add_timer(ctx->event_ctx, ctx, timeval_zero(), composite_trigger, ctx);
 140         }
 141         ctx->state = COMPOSITE_STATE_DONE;
 142         if (ctx->async.fn != NULL) {
 143                 ctx->async.fn(ctx);
 144         }
 145 }
 146
 147 _PUBLIC_ void composite_continue(struct composite_context *ctx,
 148                                  struct composite_context *new_ctx,
 149                                  void (*continuation)(struct composite_context *),
 150                                  void *private_data)
 151 {
 152         if (composite_nomem(new_ctx, ctx)) return;
 153         new_ctx->async.fn = continuation;
 154         new_ctx->async.private_data = private_data;
 155
 156         /* if we are setting up a continuation, and the context has
 157            already finished, then we should run the callback with an
 158            immediate event, otherwise we can be stuck forever */
 159         if (new_ctx->state >= COMPOSITE_STATE_DONE && continuation) {
 160                 tevent_add_timer(new_ctx->event_ctx, new_ctx, timeval_zero(), composite_trigger, new_ctx);
 161         }
 162 }
 163
 164 _PUBLIC_ void composite_continue_smb(struct composite_context *ctx,
 165                                      struct smbcli_request *new_req,
 166                                      void (*continuation)(struct smbcli_request *),
 167                                      void *private_data)
 168 {
 169         if (composite_nomem(new_req, ctx)) return;
 170         new_req->async.fn = continuation;
 171         new_req->async.private_data = private_data;
 172 }
 173
 174 _PUBLIC_ void composite_continue_smb2(struct composite_context *ctx,
 175                                       struct smb2_request *new_req,
 176                                       void (*continuation)(struct smb2_request *),
 177                                       void *private_data)
 178 {
 179         if (composite_nomem(new_req, ctx)) return;
 180         new_req->async.fn = continuation;
 181         new_req->async.private_data = private_data;
 182 }
 183
 184 _PUBLIC_ void composite_continue_nbt(struct composite_context *ctx,
 185                                      struct nbt_name_request *new_req,
 186                                      void (*continuation)(struct nbt_name_request *),
 187                                      void *private_data)
 188 {
 189         if (composite_nomem(new_req, ctx)) return;
 190         new_req->async.fn = continuation;
 191         new_req->async.private_data = private_data;
 192 }