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 "librpc/rpc/dcerpc.h"
  31 #include "../libcli/nbt/libnbt.h"
  32
  33 /*
  34  create a new composite_context structure
  35  and initialize it
  36 */
  37 _PUBLIC_ struct composite_context *composite_create(TALLOC_CTX *mem_ctx,
  38                                                     struct tevent_context *ev)
  39 {
  40         struct composite_context *c;
  41
  42         c = talloc_zero(mem_ctx, struct composite_context);
  43         if (!c) return NULL;
  44         c->state = COMPOSITE_STATE_IN_PROGRESS;
  45         c->event_ctx = ev;
  46
  47         return c;
  48 }
  49
  50 /*
  51   block until a composite function has completed, then return the status
  52 */
  53 _PUBLIC_ NTSTATUS composite_wait(struct composite_context *c)
  54 {
  55         if (c == NULL) return NT_STATUS_NO_MEMORY;
  56
  57         c->used_wait = true;
  58
  59         while (c->state < COMPOSITE_STATE_DONE) {
  60                 if (event_loop_once(c->event_ctx) != 0) {
  61                         return NT_STATUS_UNSUCCESSFUL;
  62                 }
  63         }
  64
  65         return c->status;
  66 }
  67
  68 /*
  69   block until a composite function has completed, then return the status.
  70   Free the composite context before returning
  71 */
  72 _PUBLIC_ NTSTATUS composite_wait_free(struct composite_context *c)
  73 {
  74         NTSTATUS status = composite_wait(c);
  75         talloc_free(c);
  76         return status;
  77 }
  78
  79 /*
  80    callback from composite_done() and composite_error()
  81
  82    this is used to allow for a composite function to complete without
  83    going through any state transitions. When that happens the caller
  84    has had no opportunity to fill in the async callback fields
  85    (ctx->async.fn and ctx->async.private_data) which means the usual way of
  86    dealing with composite functions doesn't work. To cope with this,
  87    we trigger a timer event that will happen then the event loop is
  88    re-entered. This gives the caller a chance to setup the callback,
  89    and allows the caller to ignore the fact that the composite
  90    function completed early
  91 */
  92 static void composite_trigger(struct tevent_context *ev, struct tevent_timer *te,
  93                               struct timeval t, void *ptr)
  94 {
  95         struct composite_context *c = talloc_get_type(ptr, struct composite_context);
  96         if (c->async.fn) {
  97                 c->async.fn(c);
  98         }
  99 }
 100
 101
 102 _PUBLIC_ void composite_error(struct composite_context *ctx, NTSTATUS status)
 103 {
 104         /* you are allowed to pass NT_STATUS_OK to composite_error(), in which
 105            case it is equivalent to composite_done() */
 106         if (NT_STATUS_IS_OK(status)) {
 107                 composite_done(ctx);
 108                 return;
 109         }
 110         if (!ctx->used_wait && !ctx->async.fn) {
 111                 event_add_timed(ctx->event_ctx, ctx, timeval_zero(), composite_trigger, ctx);
 112         }
 113         ctx->status = status;
 114         ctx->state = COMPOSITE_STATE_ERROR;
 115         if (ctx->async.fn != NULL) {
 116                 ctx->async.fn(ctx);
 117         }
 118 }
 119
 120 _PUBLIC_ bool composite_nomem(const void *p, struct composite_context *ctx)
 121 {
 122         if (p != NULL) {
 123                 return false;
 124         }
 125         composite_error(ctx, NT_STATUS_NO_MEMORY);
 126         return true;
 127 }
 128
 129 _PUBLIC_ bool composite_is_ok(struct composite_context *ctx)
 130 {
 131         if (NT_STATUS_IS_OK(ctx->status)) {
 132                 return true;
 133         }
 134         composite_error(ctx, ctx->status);
 135         return false;
 136 }
 137
 138 _PUBLIC_ void composite_done(struct composite_context *ctx)
 139 {
 140         if (!ctx->used_wait && !ctx->async.fn) {
 141                 event_add_timed(ctx->event_ctx, ctx, timeval_zero(), composite_trigger, ctx);
 142         }
 143         ctx->state = COMPOSITE_STATE_DONE;
 144         if (ctx->async.fn != NULL) {
 145                 ctx->async.fn(ctx);
 146         }
 147 }
 148
 149 _PUBLIC_ void composite_continue(struct composite_context *ctx,
 150                                  struct composite_context *new_ctx,
 151                                  void (*continuation)(struct composite_context *),
 152                                  void *private_data)
 153 {
 154         if (composite_nomem(new_ctx, ctx)) return;
 155         new_ctx->async.fn = continuation;
 156         new_ctx->async.private_data = private_data;
 157
 158         /* if we are setting up a continuation, and the context has
 159            already finished, then we should run the callback with an
 160            immediate event, otherwise we can be stuck forever */
 161         if (new_ctx->state >= COMPOSITE_STATE_DONE && continuation) {
 162                 event_add_timed(new_ctx->event_ctx, new_ctx, timeval_zero(), composite_trigger, new_ctx);
 163         }
 164 }
 165
 166 _PUBLIC_ void composite_continue_rpc(struct composite_context *ctx,
 167                                      struct rpc_request *new_req,
 168                                      void (*continuation)(struct rpc_request *),
 169                                      void *private_data)
 170 {
 171         if (composite_nomem(new_req, ctx)) return;
 172         new_req->async.callback = continuation;
 173         new_req->async.private_data = private_data;
 174 }
 175
 176 _PUBLIC_ void composite_continue_irpc(struct composite_context *ctx,
 177                                       struct irpc_request *new_req,
 178                                       void (*continuation)(struct irpc_request *),
 179                                       void *private_data)
 180 {
 181         if (composite_nomem(new_req, ctx)) return;
 182         new_req->async.fn = continuation;
 183         new_req->async.private_data = private_data;
 184 }
 185
 186 _PUBLIC_ void composite_continue_smb(struct composite_context *ctx,
 187                                      struct smbcli_request *new_req,
 188                                      void (*continuation)(struct smbcli_request *),
 189                                      void *private_data)
 190 {
 191         if (composite_nomem(new_req, ctx)) return;
 192         new_req->async.fn = continuation;
 193         new_req->async.private_data = private_data;
 194 }
 195
 196 _PUBLIC_ void composite_continue_smb2(struct composite_context *ctx,
 197                                       struct smb2_request *new_req,
 198                                       void (*continuation)(struct smb2_request *),
 199                                       void *private_data)
 200 {
 201         if (composite_nomem(new_req, ctx)) return;
 202         new_req->async.fn = continuation;
 203         new_req->async.private_data = private_data;
 204 }
 205
 206 _PUBLIC_ void composite_continue_nbt(struct composite_context *ctx,
 207                                      struct nbt_name_request *new_req,
 208                                      void (*continuation)(struct nbt_name_request *),
 209                                      void *private_data)
 210 {
 211         if (composite_nomem(new_req, ctx)) return;
 212         new_req->async.fn = continuation;
 213         new_req->async.private_data = private_data;
 214 }