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/smb2/smb2.h"
  27 #include "libcli/composite/composite.h"
  28 #include "../libcli/nbt/libnbt.h"
  29
  30 /*
  31  create a new composite_context structure
  32  and initialize it
  33 */
  34 _PUBLIC_ struct composite_context *composite_create(TALLOC_CTX *mem_ctx,
  35                                                     struct tevent_context *ev)
  36 {
  37         struct composite_context *c;
  38
  39         c = talloc_zero(mem_ctx, struct composite_context);
  40         if (!c) return NULL;
  41         c->state = COMPOSITE_STATE_IN_PROGRESS;
  42         c->event_ctx = ev;
  43
  44         return c;
  45 }
  46
  47 /*
  48   block until a composite function has completed, then return the status
  49 */
  50 _PUBLIC_ NTSTATUS composite_wait(struct composite_context *c)
  51 {
  52         if (c == NULL) return NT_STATUS_NO_MEMORY;
  53
  54         c->used_wait = true;
  55
  56         while (c->state < COMPOSITE_STATE_DONE) {
  57                 if (tevent_loop_once(c->event_ctx) != 0) {
  58                         return NT_STATUS_UNSUCCESSFUL;
  59                 }
  60         }
  61
  62         return c->status;
  63 }
  64
  65 /*
  66   block until a composite function has completed, then return the status.
  67   Free the composite context before returning
  68 */
  69 _PUBLIC_ NTSTATUS composite_wait_free(struct composite_context *c)
  70 {
  71         NTSTATUS status = composite_wait(c);
  72         talloc_free(c);
  73         return status;
  74 }
  75
  76 /*
  77    callback from composite_done() and composite_error()
  78
  79    this is used to allow for a composite function to complete without
  80    going through any state transitions. When that happens the caller
  81    has had no opportunity to fill in the async callback fields
  82    (ctx->async.fn and ctx->async.private_data) which means the usual way of
  83    dealing with composite functions doesn't work. To cope with this,
  84    we trigger a timer event that will happen then the event loop is
  85    re-entered. This gives the caller a chance to setup the callback,
  86    and allows the caller to ignore the fact that the composite
  87    function completed early
  88 */
  89 static void composite_trigger(struct tevent_context *ev, struct tevent_timer *te,
  90                               struct timeval t, void *ptr)
  91 {
  92         struct composite_context *c = talloc_get_type(ptr, struct composite_context);
  93         if (c->async.fn) {
  94                 c->async.fn(c);
  95         }
  96 }
  97
  98
  99 _PUBLIC_ void composite_error(struct composite_context *ctx, NTSTATUS status)
 100 {
 101         /* you are allowed to pass NT_STATUS_OK to composite_error(), in which
 102            case it is equivalent to composite_done() */
 103         if (NT_STATUS_IS_OK(status)) {
 104                 composite_done(ctx);
 105                 return;
 106         }
 107         if (!ctx->used_wait && !ctx->async.fn) {
 108                 tevent_add_timer(ctx->event_ctx, ctx, timeval_zero(), composite_trigger, ctx);
 109         }
 110         ctx->status = status;
 111         ctx->state = COMPOSITE_STATE_ERROR;
 112         if (ctx->async.fn != NULL) {
 113                 ctx->async.fn(ctx);
 114         }
 115 }
 116
 117 _PUBLIC_ bool composite_nomem(const void *p, struct composite_context *ctx)
 118 {
 119         if (p != NULL) {
 120                 return false;
 121         }
 122         composite_error(ctx, NT_STATUS_NO_MEMORY);
 123         return true;
 124 }
 125
 126 _PUBLIC_ bool composite_is_ok(struct composite_context *ctx)
 127 {
 128         if (NT_STATUS_IS_OK(ctx->status)) {
 129                 return true;
 130         }
 131         composite_error(ctx, ctx->status);
 132         return false;
 133 }
 134
 135 _PUBLIC_ void composite_done(struct composite_context *ctx)
 136 {
 137         if (!ctx->used_wait && !ctx->async.fn) {
 138                 tevent_add_timer(ctx->event_ctx, ctx, timeval_zero(), composite_trigger, ctx);
 139         }
 140         ctx->state = COMPOSITE_STATE_DONE;
 141         if (ctx->async.fn != NULL) {
 142                 ctx->async.fn(ctx);
 143         }
 144 }
 145
 146 _PUBLIC_ void composite_continue(struct composite_context *ctx,
 147                                  struct composite_context *new_ctx,
 148                                  void (*continuation)(struct composite_context *),
 149                                  void *private_data)
 150 {
 151         if (composite_nomem(new_ctx, ctx)) return;
 152         new_ctx->async.fn = continuation;
 153         new_ctx->async.private_data = private_data;
 154
 155         /* if we are setting up a continuation, and the context has
 156            already finished, then we should run the callback with an
 157            immediate event, otherwise we can be stuck forever */
 158         if (new_ctx->state >= COMPOSITE_STATE_DONE && continuation) {
 159                 tevent_add_timer(new_ctx->event_ctx, new_ctx, timeval_zero(), composite_trigger, new_ctx);
 160         }
 161 }
 162
 163 _PUBLIC_ void composite_continue_smb(struct composite_context *ctx,
 164                                      struct smbcli_request *new_req,
 165                                      void (*continuation)(struct smbcli_request *),
 166                                      void *private_data)
 167 {
 168         if (composite_nomem(new_req, ctx)) return;
 169         if (new_req->state > SMBCLI_REQUEST_RECV) {
 170                 composite_error(ctx, new_req->status);
 171                 return;
 172         }
 173         new_req->async.fn = continuation;
 174         new_req->async.private_data = private_data;
 175 }
 176
 177 _PUBLIC_ void composite_continue_smb2(struct composite_context *ctx,
 178                                       struct smb2_request *new_req,
 179                                       void (*continuation)(struct smb2_request *),
 180                                       void *private_data)
 181 {
 182         if (composite_nomem(new_req, ctx)) return;
 183         if (new_req->state > SMB2_REQUEST_RECV) {
 184                 composite_error(ctx, new_req->status);
 185                 return;
 186         }
 187         new_req->async.fn = continuation;
 188         new_req->async.private_data = private_data;
 189 }
 190
 191 _PUBLIC_ void composite_continue_nbt(struct composite_context *ctx,
 192                                      struct nbt_name_request *new_req,
 193                                      void (*continuation)(struct nbt_name_request *),
 194                                      void *private_data)
 195 {
 196         if (composite_nomem(new_req, ctx)) return;
 197         new_req->async.fn = continuation;
 198         new_req->async.private_data = private_data;
 199 }