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 "lib/messaging/irpc.h"
  30 #include "../libcli/nbt/libnbt.h"
  31
  32 /*
  33  create a new composite_context structure
  34  and initialize it
  35 */
  36 _PUBLIC_ struct composite_context *composite_create(TALLOC_CTX *mem_ctx,
  37                                                     struct tevent_context *ev)
  38 {
  39         struct composite_context *c;
  40
  41         c = talloc_zero(mem_ctx, struct composite_context);
  42         if (!c) return NULL;
  43         c->state = COMPOSITE_STATE_IN_PROGRESS;
  44         c->event_ctx = ev;
  45
  46         return c;
  47 }
  48
  49 /*
  50   block until a composite function has completed, then return the status
  51 */
  52 _PUBLIC_ NTSTATUS composite_wait(struct composite_context *c)
  53 {
  54         if (c == NULL) return NT_STATUS_NO_MEMORY;
  55
  56         c->used_wait = true;
  57
  58         while (c->state < COMPOSITE_STATE_DONE) {
  59                 if (event_loop_once(c->event_ctx) != 0) {
  60                         return NT_STATUS_UNSUCCESSFUL;
  61                 }
  62         }
  63
  64         return c->status;
  65 }
  66
  67 /*
  68   block until a composite function has completed, then return the status.
  69   Free the composite context before returning
  70 */
  71 _PUBLIC_ NTSTATUS composite_wait_free(struct composite_context *c)
  72 {
  73         NTSTATUS status = composite_wait(c);
  74         talloc_free(c);
  75         return status;
  76 }
  77
  78 /*
  79    callback from composite_done() and composite_error()
  80
  81    this is used to allow for a composite function to complete without
  82    going through any state transitions. When that happens the caller
  83    has had no opportunity to fill in the async callback fields
  84    (ctx->async.fn and ctx->async.private_data) which means the usual way of
  85    dealing with composite functions doesn't work. To cope with this,
  86    we trigger a timer event that will happen then the event loop is
  87    re-entered. This gives the caller a chance to setup the callback,
  88    and allows the caller to ignore the fact that the composite
  89    function completed early
  90 */
  91 static void composite_trigger(struct tevent_context *ev, struct tevent_timer *te,
  92                               struct timeval t, void *ptr)
  93 {
  94         struct composite_context *c = talloc_get_type(ptr, struct composite_context);
  95         if (c->async.fn) {
  96                 c->async.fn(c);
  97         }
  98 }
  99
 100
 101 _PUBLIC_ void composite_error(struct composite_context *ctx, NTSTATUS status)
 102 {
 103         /* you are allowed to pass NT_STATUS_OK to composite_error(), in which
 104            case it is equivalent to composite_done() */
 105         if (NT_STATUS_IS_OK(status)) {
 106                 composite_done(ctx);
 107                 return;
 108         }
 109         if (!ctx->used_wait && !ctx->async.fn) {
 110                 event_add_timed(ctx->event_ctx, ctx, timeval_zero(), composite_trigger, ctx);
 111         }
 112         ctx->status = status;
 113         ctx->state = COMPOSITE_STATE_ERROR;
 114         if (ctx->async.fn != NULL) {
 115                 ctx->async.fn(ctx);
 116         }
 117 }
 118
 119 _PUBLIC_ bool composite_nomem(const void *p, struct composite_context *ctx)
 120 {
 121         if (p != NULL) {
 122                 return false;
 123         }
 124         composite_error(ctx, NT_STATUS_NO_MEMORY);
 125         return true;
 126 }
 127
 128 _PUBLIC_ bool composite_is_ok(struct composite_context *ctx)
 129 {
 130         if (NT_STATUS_IS_OK(ctx->status)) {
 131                 return true;
 132         }
 133         composite_error(ctx, ctx->status);
 134         return false;
 135 }
 136
 137 _PUBLIC_ void composite_done(struct composite_context *ctx)
 138 {
 139         if (!ctx->used_wait && !ctx->async.fn) {
 140                 event_add_timed(ctx->event_ctx, ctx, timeval_zero(), composite_trigger, ctx);
 141         }
 142         ctx->state = COMPOSITE_STATE_DONE;
 143         if (ctx->async.fn != NULL) {
 144                 ctx->async.fn(ctx);
 145         }
 146 }
 147
 148 _PUBLIC_ void composite_continue(struct composite_context *ctx,
 149                                  struct composite_context *new_ctx,
 150                                  void (*continuation)(struct composite_context *),
 151                                  void *private_data)
 152 {
 153         if (composite_nomem(new_ctx, ctx)) return;
 154         new_ctx->async.fn = continuation;
 155         new_ctx->async.private_data = private_data;
 156
 157         /* if we are setting up a continuation, and the context has
 158            already finished, then we should run the callback with an
 159            immediate event, otherwise we can be stuck forever */
 160         if (new_ctx->state >= COMPOSITE_STATE_DONE && continuation) {
 161                 event_add_timed(new_ctx->event_ctx, new_ctx, timeval_zero(), composite_trigger, new_ctx);
 162         }
 163 }
 164
 165 _PUBLIC_ void composite_continue_irpc(struct composite_context *ctx,
 166                                       struct irpc_request *new_req,
 167                                       void (*continuation)(struct irpc_request *),
 168                                       void *private_data)
 169 {
 170         if (composite_nomem(new_req, ctx)) return;
 171         new_req->async.fn = continuation;
 172         new_req->async.private_data = private_data;
 173 }
 174
 175 _PUBLIC_ void composite_continue_smb(struct composite_context *ctx,
 176                                      struct smbcli_request *new_req,
 177                                      void (*continuation)(struct smbcli_request *),
 178                                      void *private_data)
 179 {
 180         if (composite_nomem(new_req, ctx)) return;
 181         new_req->async.fn = continuation;
 182         new_req->async.private_data = private_data;
 183 }
 184
 185 _PUBLIC_ void composite_continue_smb2(struct composite_context *ctx,
 186                                       struct smb2_request *new_req,
 187                                       void (*continuation)(struct smb2_request *),
 188                                       void *private_data)
 189 {
 190         if (composite_nomem(new_req, ctx)) return;
 191         new_req->async.fn = continuation;
 192         new_req->async.private_data = private_data;
 193 }
 194
 195 _PUBLIC_ void composite_continue_nbt(struct composite_context *ctx,
 196                                      struct nbt_name_request *new_req,
 197                                      void (*continuation)(struct nbt_name_request *),
 198                                      void *private_data)
 199 {
 200         if (composite_nomem(new_req, ctx)) return;
 201         new_req->async.fn = continuation;
 202         new_req->async.private_data = private_data;
 203 }