lib/async_req/async_sock.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    async socket syscalls
   4    Copyright (C) Volker Lendecke 2008
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "includes.h"
  21 #include "lib/talloc/talloc.h"
  22 #include "lib/tevent/tevent.h"
  23 #include "lib/async_req/async_req.h"
  24 #include "lib/async_req/async_sock.h"
  25 #include "lib/util/tevent_unix.h"
  26 #include <fcntl.h>
  27
  28 #ifndef TALLOC_FREE
  29 #define TALLOC_FREE(ctx) do { talloc_free(ctx); ctx=NULL; } while(0)
  30 #endif
  31
  32 /**
  33  * @brief Map async_req states to unix-style errnos
  34  * @param[in]  req      The async req to get the state from
  35  * @param[out] err      Pointer to take the unix-style errno
  36  *
  37  * @return true if the async_req is in an error state, false otherwise
  38  */
  39
  40 bool async_req_is_errno(struct async_req *req, int *err)
  41 {
  42         enum async_req_state state;
  43         uint64_t error;
  44
  45         if (!async_req_is_error(req, &state, &error)) {
  46                 return false;
  47         }
  48
  49         switch (state) {
  50         case ASYNC_REQ_USER_ERROR:
  51                 *err = (int)error;
  52                 break;
  53         case ASYNC_REQ_TIMED_OUT:
  54 #ifdef ETIMEDOUT
  55                 *err = ETIMEDOUT;
  56 #else
  57                 *err = EAGAIN;
  58 #endif
  59                 break;
  60         case ASYNC_REQ_NO_MEMORY:
  61                 *err = ENOMEM;
  62                 break;
  63         default:
  64                 *err = EIO;
  65                 break;
  66         }
  67         return true;
  68 }
  69
  70 int async_req_simple_recv_errno(struct async_req *req)
  71 {
  72         int err;
  73
  74         if (async_req_is_errno(req, &err)) {
  75                 return err;
  76         }
  77
  78         return 0;
  79 }
  80
  81 struct async_send_state {
  82         int fd;
  83         const void *buf;
  84         size_t len;
  85         int flags;
  86         ssize_t sent;
  87 };
  88
  89 static void async_send_handler(struct tevent_context *ev,
  90                                struct tevent_fd *fde,
  91                                uint16_t flags, void *private_data);
  92
  93 struct tevent_req *async_send_send(TALLOC_CTX *mem_ctx,
  94                                    struct tevent_context *ev,
  95                                    int fd, const void *buf, size_t len,
  96                                    int flags)
  97 {
  98         struct tevent_req *result;
  99         struct async_send_state *state;
 100         struct tevent_fd *fde;
 101
 102         result = tevent_req_create(mem_ctx, &state, struct async_send_state);
 103         if (result == NULL) {
 104                 return result;
 105         }
 106         state->fd = fd;
 107         state->buf = buf;
 108         state->len = len;
 109         state->flags = flags;
 110
 111         fde = tevent_add_fd(ev, state, fd, TEVENT_FD_WRITE, async_send_handler,
 112                             result);
 113         if (fde == NULL) {
 114                 TALLOC_FREE(result);
 115                 return NULL;
 116         }
 117         return result;
 118 }
 119
 120 static void async_send_handler(struct tevent_context *ev,
 121                                struct tevent_fd *fde,
 122                                uint16_t flags, void *private_data)
 123 {
 124         struct tevent_req *req = talloc_get_type_abort(
 125                 private_data, struct tevent_req);
 126         struct async_send_state *state =
 127                 tevent_req_data(req, struct async_send_state);
 128
 129         state->sent = send(state->fd, state->buf, state->len, state->flags);
 130         if (state->sent == -1) {
 131                 tevent_req_error(req, errno);
 132                 return;
 133         }
 134         tevent_req_done(req);
 135 }
 136
 137 ssize_t async_send_recv(struct tevent_req *req, int *perrno)
 138 {
 139         struct async_send_state *state =
 140                 tevent_req_data(req, struct async_send_state);
 141
 142         if (tevent_req_is_unix_error(req, perrno)) {
 143                 return -1;
 144         }
 145         return state->sent;
 146 }
 147
 148 struct async_recv_state {
 149         int fd;
 150         void *buf;
 151         size_t len;
 152         int flags;
 153         ssize_t received;
 154 };
 155
 156 static void async_recv_handler(struct tevent_context *ev,
 157                                struct tevent_fd *fde,
 158                                uint16_t flags, void *private_data);
 159
 160 struct tevent_req *async_recv_send(TALLOC_CTX *mem_ctx,
 161                                    struct tevent_context *ev,
 162                                    int fd, void *buf, size_t len, int flags)
 163 {
 164         struct tevent_req *result;
 165         struct async_recv_state *state;
 166         struct tevent_fd *fde;
 167
 168         result = tevent_req_create(mem_ctx, &state, struct async_recv_state);
 169         if (result == NULL) {
 170                 return result;
 171         }
 172         state->fd = fd;
 173         state->buf = buf;
 174         state->len = len;
 175         state->flags = flags;
 176
 177         fde = tevent_add_fd(ev, state, fd, TEVENT_FD_READ, async_recv_handler,
 178                             result);
 179         if (fde == NULL) {
 180                 TALLOC_FREE(result);
 181                 return NULL;
 182         }
 183         return result;
 184 }
 185
 186 static void async_recv_handler(struct tevent_context *ev,
 187                                struct tevent_fd *fde,
 188                                uint16_t flags, void *private_data)
 189 {
 190         struct tevent_req *req = talloc_get_type_abort(
 191                 private_data, struct tevent_req);
 192         struct async_recv_state *state =
 193                 tevent_req_data(req, struct async_recv_state);
 194
 195         state->received = recv(state->fd, state->buf, state->len,
 196                                state->flags);
 197         if (state->received == -1) {
 198                 tevent_req_error(req, errno);
 199                 return;
 200         }
 201         tevent_req_done(req);
 202 }
 203
 204 ssize_t async_recv_recv(struct tevent_req *req, int *perrno)
 205 {
 206         struct async_recv_state *state =
 207                 tevent_req_data(req, struct async_recv_state);
 208
 209         if (tevent_req_is_unix_error(req, perrno)) {
 210                 return -1;
 211         }
 212         return state->received;
 213 }
 214
 215 struct async_connect_state {
 216         int fd;
 217         int result;
 218         int sys_errno;
 219         long old_sockflags;
 220 };
 221
 222 static void async_connect_connected(struct tevent_context *ev,
 223                                     struct tevent_fd *fde, uint16_t flags,
 224                                     void *priv);
 225
 226 /**
 227  * @brief async version of connect(2)
 228  * @param[in] mem_ctx   The memory context to hang the result off
 229  * @param[in] ev        The event context to work from
 230  * @param[in] fd        The socket to recv from
 231  * @param[in] address   Where to connect?
 232  * @param[in] address_len Length of *address
 233  * @retval The async request
 234  *
 235  * This function sets the socket into non-blocking state to be able to call
 236  * connect in an async state. This will be reset when the request is finished.
 237  */
 238
 239 struct tevent_req *async_connect_send(TALLOC_CTX *mem_ctx,
 240                                       struct tevent_context *ev,
 241                                       int fd, const struct sockaddr *address,
 242                                       socklen_t address_len)
 243 {
 244         struct tevent_req *result;
 245         struct async_connect_state *state;
 246         struct tevent_fd *fde;
 247
 248         result = tevent_req_create(
 249                 mem_ctx, &state, struct async_connect_state);
 250         if (result == NULL) {
 251                 return NULL;
 252         }
 253
 254         /**
 255          * We have to set the socket to nonblocking for async connect(2). Keep
 256          * the old sockflags around.
 257          */
 258
 259         state->fd = fd;
 260         state->sys_errno = 0;
 261
 262         state->old_sockflags = fcntl(fd, F_GETFL, 0);
 263         if (state->old_sockflags == -1) {
 264                 goto post_errno;
 265         }
 266
 267         set_blocking(fd, false);
 268
 269         state->result = connect(fd, address, address_len);
 270         if (state->result == 0) {
 271                 tevent_req_done(result);
 272                 goto done;
 273         }
 274
 275         /**
 276          * A number of error messages show that something good is progressing
 277          * and that we have to wait for readability.
 278          *
 279          * If none of them are present, bail out.
 280          */
 281
 282         if (!(errno == EINPROGRESS || errno == EALREADY ||
 283 #ifdef EISCONN
 284               errno == EISCONN ||
 285 #endif
 286               errno == EAGAIN || errno == EINTR)) {
 287                 state->sys_errno = errno;
 288                 goto post_errno;
 289         }
 290
 291         fde = tevent_add_fd(ev, state, fd, TEVENT_FD_READ | TEVENT_FD_WRITE,
 292                            async_connect_connected, result);
 293         if (fde == NULL) {
 294                 state->sys_errno = ENOMEM;
 295                 goto post_errno;
 296         }
 297         return result;
 298
 299  post_errno:
 300         tevent_req_error(result, state->sys_errno);
 301  done:
 302         fcntl(fd, F_SETFL, state->old_sockflags);
 303         return tevent_req_post(result, ev);
 304 }
 305
 306 /**
 307  * fde event handler for connect(2)
 308  * @param[in] ev        The event context that sent us here
 309  * @param[in] fde       The file descriptor event associated with the connect
 310  * @param[in] flags     Indicate read/writeability of the socket
 311  * @param[in] priv      private data, "struct async_req *" in this case
 312  */
 313
 314 static void async_connect_connected(struct tevent_context *ev,
 315                                     struct tevent_fd *fde, uint16_t flags,
 316                                     void *priv)
 317 {
 318         struct tevent_req *req = talloc_get_type_abort(
 319                 priv, struct tevent_req);
 320         struct async_connect_state *state =
 321                 tevent_req_data(req, struct async_connect_state);
 322
 323         TALLOC_FREE(fde);
 324
 325         /*
 326          * Stevens, Network Programming says that if there's a
 327          * successful connect, the socket is only writable. Upon an
 328          * error, it's both readable and writable.
 329          */
 330         if ((flags & (TEVENT_FD_READ|TEVENT_FD_WRITE))
 331             == (TEVENT_FD_READ|TEVENT_FD_WRITE)) {
 332                 int sockerr;
 333                 socklen_t err_len = sizeof(sockerr);
 334
 335                 if (getsockopt(state->fd, SOL_SOCKET, SO_ERROR,
 336                                (void *)&sockerr, &err_len) == 0) {
 337                         errno = sockerr;
 338                 }
 339
 340                 state->sys_errno = errno;
 341
 342                 DEBUG(10, ("connect returned %s\n", strerror(errno)));
 343
 344                 fcntl(state->fd, F_SETFL, state->old_sockflags);
 345                 tevent_req_error(req, state->sys_errno);
 346                 return;
 347         }
 348
 349         state->sys_errno = 0;
 350         tevent_req_done(req);
 351 }
 352
 353 int async_connect_recv(struct tevent_req *req, int *perrno)
 354 {
 355         struct async_connect_state *state =
 356                 tevent_req_data(req, struct async_connect_state);
 357         int err;
 358
 359         fcntl(state->fd, F_SETFL, state->old_sockflags);
 360
 361         if (tevent_req_is_unix_error(req, &err)) {
 362                 *perrno = err;
 363                 return -1;
 364         }
 365
 366         if (state->sys_errno == 0) {
 367                 return 0;
 368         }
 369
 370         *perrno = state->sys_errno;
 371         return -1;
 372 }
 373
 374 struct writev_state {
 375         struct tevent_context *ev;
 376         int fd;
 377         struct iovec *iov;
 378         int count;
 379         size_t total_size;
 380 };
 381
 382 static void writev_trigger(struct tevent_req *req, void *private_data);
 383 static void writev_handler(struct tevent_context *ev, struct tevent_fd *fde,
 384                            uint16_t flags, void *private_data);
 385
 386 struct tevent_req *writev_send(TALLOC_CTX *mem_ctx, struct tevent_context *ev,
 387                                struct tevent_queue *queue, int fd,
 388                                struct iovec *iov, int count)
 389 {
 390         struct tevent_req *result;
 391         struct writev_state *state;
 392
 393         result = tevent_req_create(mem_ctx, &state, struct writev_state);
 394         if (result == NULL) {
 395                 return NULL;
 396         }
 397         state->ev = ev;
 398         state->fd = fd;
 399         state->total_size = 0;
 400         state->count = count;
 401         state->iov = (struct iovec *)talloc_memdup(
 402                 state, iov, sizeof(struct iovec) * count);
 403         if (state->iov == NULL) {
 404                 goto fail;
 405         }
 406
 407         if (!tevent_queue_add(queue, ev, result, writev_trigger, NULL)) {
 408                 goto fail;
 409         }
 410         return result;
 411  fail:
 412         TALLOC_FREE(result);
 413         return NULL;
 414 }
 415
 416 static void writev_trigger(struct tevent_req *req, void *private_data)
 417 {
 418         struct writev_state *state = tevent_req_data(req, struct writev_state);
 419         struct tevent_fd *fde;
 420
 421         fde = tevent_add_fd(state->ev, state, state->fd, TEVENT_FD_WRITE,
 422                             writev_handler, req);
 423         if (fde == NULL) {
 424                 tevent_req_error(req, ENOMEM);
 425         }
 426 }
 427
 428 static void writev_handler(struct tevent_context *ev, struct tevent_fd *fde,
 429                            uint16_t flags, void *private_data)
 430 {
 431         struct tevent_req *req = talloc_get_type_abort(
 432                 private_data, struct tevent_req);
 433         struct writev_state *state =
 434                 tevent_req_data(req, struct writev_state);
 435         size_t to_write, written;
 436         int i;
 437
 438         to_write = 0;
 439
 440         for (i=0; i<state->count; i++) {
 441                 to_write += state->iov[i].iov_len;
 442         }
 443
 444         written = sys_writev(state->fd, state->iov, state->count);
 445         if (written == -1) {
 446                 tevent_req_error(req, errno);
 447                 return;
 448         }
 449         if (written == 0) {
 450                 tevent_req_error(req, EPIPE);
 451                 return;
 452         }
 453         state->total_size += written;
 454
 455         if (written == to_write) {
 456                 tevent_req_done(req);
 457                 return;
 458         }
 459
 460         /*
 461          * We've written less than we were asked to, drop stuff from
 462          * state->iov.
 463          */
 464
 465         while (written > 0) {
 466                 if (written < state->iov[0].iov_len) {
 467                         state->iov[0].iov_base =
 468                                 (char *)state->iov[0].iov_base + written;
 469                         state->iov[0].iov_len -= written;
 470                         break;
 471                 }
 472                 written -= state->iov[0].iov_len;
 473                 state->iov += 1;
 474                 state->count -= 1;
 475         }
 476 }
 477
 478 ssize_t writev_recv(struct tevent_req *req, int *perrno)
 479 {
 480         struct writev_state *state =
 481                 tevent_req_data(req, struct writev_state);
 482
 483         if (tevent_req_is_unix_error(req, perrno)) {
 484                 return -1;
 485         }
 486         return state->total_size;
 487 }
 488
 489 struct read_packet_state {
 490         int fd;
 491         uint8_t *buf;
 492         size_t nread;
 493         ssize_t (*more)(uint8_t *buf, size_t buflen, void *private_data);
 494         void *private_data;
 495 };
 496
 497 static void read_packet_handler(struct tevent_context *ev,
 498                                 struct tevent_fd *fde,
 499                                 uint16_t flags, void *private_data);
 500
 501 struct tevent_req *read_packet_send(TALLOC_CTX *mem_ctx,
 502                                     struct tevent_context *ev,
 503                                     int fd, size_t initial,
 504                                     ssize_t (*more)(uint8_t *buf,
 505                                                     size_t buflen,
 506                                                     void *private_data),
 507                                     void *private_data)
 508 {
 509         struct tevent_req *result;
 510         struct read_packet_state *state;
 511         struct tevent_fd *fde;
 512
 513         result = tevent_req_create(mem_ctx, &state, struct read_packet_state);
 514         if (result == NULL) {
 515                 return NULL;
 516         }
 517         state->fd = fd;
 518         state->nread = 0;
 519         state->more = more;
 520         state->private_data = private_data;
 521
 522         state->buf = talloc_array(state, uint8_t, initial);
 523         if (state->buf == NULL) {
 524                 goto fail;
 525         }
 526
 527         fde = tevent_add_fd(ev, state, fd, TEVENT_FD_READ, read_packet_handler,
 528                             result);
 529         if (fde == NULL) {
 530                 goto fail;
 531         }
 532         return result;
 533  fail:
 534         TALLOC_FREE(result);
 535         return NULL;
 536 }
 537
 538 static void read_packet_handler(struct tevent_context *ev,
 539                                 struct tevent_fd *fde,
 540                                 uint16_t flags, void *private_data)
 541 {
 542         struct tevent_req *req = talloc_get_type_abort(
 543                 private_data, struct tevent_req);
 544         struct read_packet_state *state =
 545                 tevent_req_data(req, struct read_packet_state);
 546         size_t total = talloc_get_size(state->buf);
 547         ssize_t nread, more;
 548         uint8_t *tmp;
 549
 550         nread = recv(state->fd, state->buf+state->nread, total-state->nread,
 551                      0);
 552         if (nread == -1) {
 553                 tevent_req_error(req, errno);
 554                 return;
 555         }
 556         if (nread == 0) {
 557                 tevent_req_error(req, EPIPE);
 558                 return;
 559         }
 560
 561         state->nread += nread;
 562         if (state->nread < total) {
 563                 /* Come back later */
 564                 return;
 565         }
 566
 567         /*
 568          * We got what was initially requested. See if "more" asks for -- more.
 569          */
 570         if (state->more == NULL) {
 571                 /* Nobody to ask, this is a async read_data */
 572                 tevent_req_done(req);
 573                 return;
 574         }
 575
 576         more = state->more(state->buf, total, state->private_data);
 577         if (more == -1) {
 578                 /* We got an invalid packet, tell the caller */
 579                 tevent_req_error(req, EIO);
 580                 return;
 581         }
 582         if (more == 0) {
 583                 /* We're done, full packet received */
 584                 tevent_req_done(req);
 585                 return;
 586         }
 587
 588         tmp = TALLOC_REALLOC_ARRAY(state, state->buf, uint8_t, total+more);
 589         if (tevent_req_nomem(tmp, req)) {
 590                 return;
 591         }
 592         state->buf = tmp;
 593 }
 594
 595 ssize_t read_packet_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
 596                          uint8_t **pbuf, int *perrno)
 597 {
 598         struct read_packet_state *state =
 599                 tevent_req_data(req, struct read_packet_state);
 600
 601         if (tevent_req_is_unix_error(req, perrno)) {
 602                 return -1;
 603         }
 604         *pbuf = talloc_move(mem_ctx, &state->buf);
 605         return talloc_get_size(*pbuf);
 606 }