lib/tsocket/tsocket_helpers.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    Copyright (C) Stefan Metzmacher 2009
   5
   6      ** NOTE! The following LGPL license applies to the tevent
   7      ** library. This does NOT imply that all of Samba is released
   8      ** under the LGPL
   9
  10    This library is free software; you can redistribute it and/or
  11    modify it under the terms of the GNU Lesser General Public
  12    License as published by the Free Software Foundation; either
  13    version 3 of the License, or (at your option) any later version.
  14
  15    This library is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18    Lesser General Public License for more details.
  19
  20    You should have received a copy of the GNU Lesser General Public
  21    License along with this library; if not, see <http://www.gnu.org/licenses/>.
  22 */
  23
  24 #include "replace.h"
  25 #include "system/filesys.h"
  26 #include "tsocket.h"
  27 #include "tsocket_internal.h"
  28
  29 struct tdgram_sendto_queue_state {
  30         /* this structs are owned by the caller */
  31         struct {
  32                 struct tevent_context *ev;
  33                 struct tdgram_context *dgram;
  34                 const uint8_t *buf;
  35                 size_t len;
  36                 const struct tsocket_address *dst;
  37         } caller;
  38         ssize_t ret;
  39 };
  40
  41 static void tdgram_sendto_queue_trigger(struct tevent_req *req,
  42                                          void *private_data);
  43 static void tdgram_sendto_queue_done(struct tevent_req *subreq);
  44
  45 /**
  46  * @brief Queue a dgram blob for sending through the socket
  47  * @param[in] mem_ctx   The memory context for the result
  48  * @param[in] ev        The event context the operation should work on
  49  * @param[in] dgram     The tdgram_context to send the message buffer
  50  * @param[in] queue     The existing dgram queue
  51  * @param[in] buf       The message buffer
  52  * @param[in] len       The message length
  53  * @param[in] dst       The destination socket address
  54  * @retval              The async request handle
  55  *
  56  * This function queues a blob for sending to destination through an existing
  57  * dgram socket. The async callback is triggered when the whole blob is
  58  * delivered to the underlying system socket.
  59  *
  60  * The caller needs to make sure that all non-scalar input parameters hang
  61  * arround for the whole lifetime of the request.
  62  */
  63 struct tevent_req *tdgram_sendto_queue_send(TALLOC_CTX *mem_ctx,
  64                                             struct tevent_context *ev,
  65                                             struct tdgram_context *dgram,
  66                                             struct tevent_queue *queue,
  67                                             const uint8_t *buf,
  68                                             size_t len,
  69                                             struct tsocket_address *dst)
  70 {
  71         struct tevent_req *req;
  72         struct tdgram_sendto_queue_state *state;
  73         bool ok;
  74
  75         req = tevent_req_create(mem_ctx, &state,
  76                                 struct tdgram_sendto_queue_state);
  77         if (!req) {
  78                 return NULL;
  79         }
  80
  81         state->caller.ev        = ev;
  82         state->caller.dgram     = dgram;
  83         state->caller.buf       = buf;
  84         state->caller.len       = len;
  85         state->caller.dst       = dst;
  86         state->ret              = -1;
  87
  88         ok = tevent_queue_add(queue,
  89                               ev,
  90                               req,
  91                               tdgram_sendto_queue_trigger,
  92                               NULL);
  93         if (!ok) {
  94                 tevent_req_nomem(NULL, req);
  95                 goto post;
  96         }
  97
  98         return req;
  99
 100  post:
 101         tevent_req_post(req, ev);
 102         return req;
 103 }
 104
 105 static void tdgram_sendto_queue_trigger(struct tevent_req *req,
 106                                          void *private_data)
 107 {
 108         struct tdgram_sendto_queue_state *state = tevent_req_data(req,
 109                                         struct tdgram_sendto_queue_state);
 110         struct tevent_req *subreq;
 111
 112         subreq = tdgram_sendto_send(state,
 113                                     state->caller.ev,
 114                                     state->caller.dgram,
 115                                     state->caller.buf,
 116                                     state->caller.len,
 117                                     state->caller.dst);
 118         if (tevent_req_nomem(subreq, req)) {
 119                 return;
 120         }
 121         tevent_req_set_callback(subreq, tdgram_sendto_queue_done, req);
 122 }
 123
 124 static void tdgram_sendto_queue_done(struct tevent_req *subreq)
 125 {
 126         struct tevent_req *req = tevent_req_callback_data(subreq,
 127                                  struct tevent_req);
 128         struct tdgram_sendto_queue_state *state = tevent_req_data(req,
 129                                         struct tdgram_sendto_queue_state);
 130         ssize_t ret;
 131         int sys_errno;
 132
 133         ret = tdgram_sendto_recv(subreq, &sys_errno);
 134         talloc_free(subreq);
 135         if (ret == -1) {
 136                 tevent_req_error(req, sys_errno);
 137                 return;
 138         }
 139         state->ret = ret;
 140
 141         tevent_req_done(req);
 142 }
 143
 144 ssize_t tdgram_sendto_queue_recv(struct tevent_req *req, int *perrno)
 145 {
 146         struct tdgram_sendto_queue_state *state = tevent_req_data(req,
 147                                         struct tdgram_sendto_queue_state);
 148         ssize_t ret;
 149
 150         ret = tsocket_simple_int_recv(req, perrno);
 151         if (ret == 0) {
 152                 ret = state->ret;
 153         }
 154
 155         tevent_req_received(req);
 156         return ret;
 157 }
 158
 159 struct tstream_readv_pdu_state {
 160         /* this structs are owned by the caller */
 161         struct {
 162                 struct tevent_context *ev;
 163                 struct tstream_context *stream;
 164                 tstream_readv_pdu_next_vector_t next_vector_fn;
 165                 void *next_vector_private;
 166         } caller;
 167
 168         /*
 169          * Each call to the callback resets iov and count
 170          * the callback allocated the iov as child of our state,
 171          * that means we are allowed to modify and free it.
 172          *
 173          * we should call the callback every time we filled the given
 174          * vector and ask for a new vector. We return if the callback
 175          * ask for 0 bytes.
 176          */
 177         struct iovec *vector;
 178         size_t count;
 179
 180         /*
 181          * the total number of bytes we read,
 182          * the return value of the _recv function
 183          */
 184         int total_read;
 185 };
 186
 187 static void tstream_readv_pdu_ask_for_next_vector(struct tevent_req *req);
 188 static void tstream_readv_pdu_readv_done(struct tevent_req *subreq);
 189
 190 struct tevent_req *tstream_readv_pdu_send(TALLOC_CTX *mem_ctx,
 191                                 struct tevent_context *ev,
 192                                 struct tstream_context *stream,
 193                                 tstream_readv_pdu_next_vector_t next_vector_fn,
 194                                 void *next_vector_private)
 195 {
 196         struct tevent_req *req;
 197         struct tstream_readv_pdu_state *state;
 198
 199         req = tevent_req_create(mem_ctx, &state,
 200                                 struct tstream_readv_pdu_state);
 201         if (!req) {
 202                 return NULL;
 203         }
 204
 205         state->caller.ev                        = ev;
 206         state->caller.stream                    = stream;
 207         state->caller.next_vector_fn            = next_vector_fn;
 208         state->caller.next_vector_private       = next_vector_private;
 209
 210         state->vector           = NULL;
 211         state->count            = 0;
 212         state->total_read       = 0;
 213
 214         tstream_readv_pdu_ask_for_next_vector(req);
 215         if (!tevent_req_is_in_progress(req)) {
 216                 goto post;
 217         }
 218
 219         return req;
 220
 221  post:
 222         return tevent_req_post(req, ev);
 223 }
 224
 225 static void tstream_readv_pdu_ask_for_next_vector(struct tevent_req *req)
 226 {
 227         struct tstream_readv_pdu_state *state = tevent_req_data(req,
 228                                             struct tstream_readv_pdu_state);
 229         int ret;
 230         size_t to_read = 0;
 231         size_t i;
 232         struct tevent_req *subreq;
 233
 234         TALLOC_FREE(state->vector);
 235         state->count = 0;
 236
 237         ret = state->caller.next_vector_fn(state->caller.stream,
 238                                            state->caller.next_vector_private,
 239                                            state, &state->vector, &state->count);
 240         if (ret == -1) {
 241                 tevent_req_error(req, errno);
 242                 return;
 243         }
 244
 245         if (state->count == 0) {
 246                 tevent_req_done(req);
 247                 return;
 248         }
 249
 250         for (i=0; i < state->count; i++) {
 251                 size_t tmp = to_read;
 252                 tmp += state->vector[i].iov_len;
 253
 254                 if (tmp < to_read) {
 255                         tevent_req_error(req, EMSGSIZE);
 256                         return;
 257                 }
 258
 259                 to_read = tmp;
 260         }
 261
 262         /*
 263          * this is invalid the next vector function should have
 264          * reported count == 0.
 265          */
 266         if (to_read == 0) {
 267                 tevent_req_error(req, EINVAL);
 268                 return;
 269         }
 270
 271         if (state->total_read + to_read < state->total_read) {
 272                 tevent_req_error(req, EMSGSIZE);
 273                 return;
 274         }
 275
 276         subreq = tstream_readv_send(state,
 277                                     state->caller.ev,
 278                                     state->caller.stream,
 279                                     state->vector,
 280                                     state->count);
 281         if (tevent_req_nomem(subreq, req)) {
 282                 return;
 283         }
 284         tevent_req_set_callback(subreq, tstream_readv_pdu_readv_done, req);
 285 }
 286
 287 static void tstream_readv_pdu_readv_done(struct tevent_req *subreq)
 288 {
 289         struct tevent_req *req = tevent_req_callback_data(subreq,
 290                                  struct tevent_req);
 291         struct tstream_readv_pdu_state *state = tevent_req_data(req,
 292                                             struct tstream_readv_pdu_state);
 293         int ret;
 294         int sys_errno;
 295
 296         ret = tstream_readv_recv(subreq, &sys_errno);
 297         if (ret == -1) {
 298                 tevent_req_error(req, sys_errno);
 299                 return;
 300         }
 301
 302         state->total_read += ret;
 303
 304         /* ask the callback for a new vector we should fill */
 305         tstream_readv_pdu_ask_for_next_vector(req);
 306 }
 307
 308 int tstream_readv_pdu_recv(struct tevent_req *req, int *perrno)
 309 {
 310         struct tstream_readv_pdu_state *state = tevent_req_data(req,
 311                                             struct tstream_readv_pdu_state);
 312         int ret;
 313
 314         ret = tsocket_simple_int_recv(req, perrno);
 315         if (ret == 0) {
 316                 ret = state->total_read;
 317         }
 318
 319         tevent_req_received(req);
 320         return ret;
 321 }
 322