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 event_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 = talloc_reference(c, ev);
  46         if (!c->event_ctx) {
  47                 talloc_free(c);
  48                 return NULL;
  49         }
  50
  51         return c;
  52 }
  53
  54 /*
  55   block until a composite function has completed, then return the status
  56 */
  57 _PUBLIC_ NTSTATUS composite_wait(struct composite_context *c)
  58 {
  59         if (c == NULL) return NT_STATUS_NO_MEMORY;
  60
  61         c->used_wait = true;
  62
  63         while (c->state < COMPOSITE_STATE_DONE) {
  64                 if (event_loop_once(c->event_ctx) != 0) {
  65                         return NT_STATUS_UNSUCCESSFUL;
  66                 }
  67         }
  68
  69         return c->status;
  70 }
  71
  72 /*
  73   block until a composite function has completed, then return the status.
  74   Free the composite context before returning
  75 */
  76 _PUBLIC_ NTSTATUS composite_wait_free(struct composite_context *c)
  77 {
  78         NTSTATUS status = composite_wait(c);
  79         talloc_free(c);
  80         return status;
  81 }
  82
  83 /*
  84    callback from composite_done() and composite_error()
  85
  86    this is used to allow for a composite function to complete without
  87    going through any state transitions. When that happens the caller
  88    has had no opportunity to fill in the async callback fields
  89    (ctx->async.fn and ctx->async.private) which means the usual way of
  90    dealing with composite functions doesn't work. To cope with this,
  91    we trigger a timer event that will happen then the event loop is
  92    re-entered. This gives the caller a chance to setup the callback,
  93    and allows the caller to ignore the fact that the composite
  94    function completed early
  95 */
  96 static void composite_trigger(struct event_context *ev, struct timed_event *te,
  97                               struct timeval t, void *ptr)
  98 {
  99         struct composite_context *c = talloc_get_type(ptr, struct composite_context);
 100         if (c->async.fn) {
 101                 c->async.fn(c);
 102         }
 103 }
 104
 105
 106 _PUBLIC_ void composite_error(struct composite_context *ctx, NTSTATUS status)
 107 {
 108         /* you are allowed to pass NT_STATUS_OK to composite_error(), in which
 109            case it is equivalent to composite_done() */
 110         if (NT_STATUS_IS_OK(status)) {
 111                 composite_done(ctx);
 112                 return;
 113         }
 114         if (!ctx->used_wait && !ctx->async.fn) {
 115                 event_add_timed(ctx->event_ctx, ctx, timeval_zero(), composite_trigger, ctx);
 116         }
 117         ctx->status = status;
 118         ctx->state = COMPOSITE_STATE_ERROR;
 119         if (ctx->async.fn != NULL) {
 120                 ctx->async.fn(ctx);
 121         }
 122 }
 123
 124 _PUBLIC_ bool composite_nomem(const void *p, struct composite_context *ctx)
 125 {
 126         if (p != NULL) {
 127                 return false;
 128         }
 129         composite_error(ctx, NT_STATUS_NO_MEMORY);
 130         return true;
 131 }
 132
 133 _PUBLIC_ bool composite_is_ok(struct composite_context *ctx)
 134 {
 135         if (NT_STATUS_IS_OK(ctx->status)) {
 136                 return true;
 137         }
 138         composite_error(ctx, ctx->status);
 139         return false;
 140 }
 141
 142 _PUBLIC_ void composite_done(struct composite_context *ctx)
 143 {
 144         if (!ctx->used_wait && !ctx->async.fn) {
 145                 event_add_timed(ctx->event_ctx, ctx, timeval_zero(), composite_trigger, ctx);
 146         }
 147         ctx->state = COMPOSITE_STATE_DONE;
 148         if (ctx->async.fn != NULL) {
 149                 ctx->async.fn(ctx);
 150         }
 151 }
 152
 153 _PUBLIC_ void composite_continue(struct composite_context *ctx,
 154                                  struct composite_context *new_ctx,
 155                                  void (*continuation)(struct composite_context *),
 156                                  void *private_data)
 157 {
 158         if (composite_nomem(new_ctx, ctx)) return;
 159         new_ctx->async.fn = continuation;
 160         new_ctx->async.private_data = private_data;
 161
 162         /* if we are setting up a continuation, and the context has
 163            already finished, then we should run the callback with an
 164            immediate event, otherwise we can be stuck forever */
 165         if (new_ctx->state >= COMPOSITE_STATE_DONE && continuation) {
 166                 event_add_timed(new_ctx->event_ctx, new_ctx, timeval_zero(), composite_trigger, new_ctx);
 167         }
 168 }
 169
 170 _PUBLIC_ void composite_continue_rpc(struct composite_context *ctx,
 171                                      struct rpc_request *new_req,
 172                                      void (*continuation)(struct rpc_request *),
 173                                      void *private_data)
 174 {
 175         if (composite_nomem(new_req, ctx)) return;
 176         new_req->async.callback = continuation;
 177         new_req->async.private_data = private_data;
 178 }
 179
 180 _PUBLIC_ void composite_continue_irpc(struct composite_context *ctx,
 181                                       struct irpc_request *new_req,
 182                                       void (*continuation)(struct irpc_request *),
 183                                       void *private_data)
 184 {
 185         if (composite_nomem(new_req, ctx)) return;
 186         new_req->async.fn = continuation;
 187         new_req->async.private = private_data;
 188 }
 189
 190 _PUBLIC_ void composite_continue_smb(struct composite_context *ctx,
 191                                      struct smbcli_request *new_req,
 192                                      void (*continuation)(struct smbcli_request *),
 193                                      void *private_data)
 194 {
 195         if (composite_nomem(new_req, ctx)) return;
 196         new_req->async.fn = continuation;
 197         new_req->async.private = private_data;
 198 }
 199
 200 _PUBLIC_ void composite_continue_smb2(struct composite_context *ctx,
 201                                       struct smb2_request *new_req,
 202                                       void (*continuation)(struct smb2_request *),
 203                                       void *private_data)
 204 {
 205         if (composite_nomem(new_req, ctx)) return;
 206         new_req->async.fn = continuation;
 207         new_req->async.private_data = private_data;
 208 }
 209
 210 _PUBLIC_ void composite_continue_nbt(struct composite_context *ctx,
 211                                      struct nbt_name_request *new_req,
 212                                      void (*continuation)(struct nbt_name_request *),
 213                                      void *private_data)
 214 {
 215         if (composite_nomem(new_req, ctx)) return;
 216         new_req->async.fn = continuation;
 217         new_req->async.private_data = private_data;
 218 }