source3/lib/util_sock.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Samba utility functions
   4    Copyright (C) Andrew Tridgell 1992-1998
   5    Copyright (C) Tim Potter      2000-2001
   6    Copyright (C) Jeremy Allison  1992-2007
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 #include "includes.h"
  23 #include "system/filesys.h"
  24 #include "../lib/util/memcache.h"
  25 #include "../lib/async_req/async_sock.h"
  26 #include "../lib/util/select.h"
  27 #include "lib/socket/interfaces.h"
  28 #include "../lib/util/tevent_unix.h"
  29 #include "../lib/util/tevent_ntstatus.h"
  30 #include "../lib/tsocket/tsocket.h"
  31 #include "lib/sys_rw.h"
  32 #include "lib/sys_rw_data.h"
  33
  34 const char *client_addr(int fd, char *addr, size_t addrlen)
  35 {
  36         return get_peer_addr(fd,addr,addrlen);
  37 }
  38
  39 #if 0
  40 /* Not currently used. JRA. */
  41 int client_socket_port(int fd)
  42 {
  43         return get_socket_port(fd);
  44 }
  45 #endif
  46
  47 /****************************************************************************
  48  Determine if a file descriptor is in fact a socket.
  49 ****************************************************************************/
  50
  51 bool is_a_socket(int fd)
  52 {
  53         int v;
  54         socklen_t l;
  55         l = sizeof(int);
  56         return(getsockopt(fd, SOL_SOCKET, SO_TYPE, (char *)&v, &l) == 0);
  57 }
  58
  59 /****************************************************************************
  60  Read from a socket.
  61 ****************************************************************************/
  62
  63 ssize_t read_udp_v4_socket(int fd,
  64                         char *buf,
  65                         size_t len,
  66                         struct sockaddr_storage *psa)
  67 {
  68         ssize_t ret;
  69         socklen_t socklen = sizeof(*psa);
  70         struct sockaddr_in *si = (struct sockaddr_in *)psa;
  71
  72         memset((char *)psa,'\0',socklen);
  73
  74         ret = (ssize_t)sys_recvfrom(fd,buf,len,0,
  75                         (struct sockaddr *)psa,&socklen);
  76         if (ret <= 0) {
  77                 /* Don't print a low debug error for a non-blocking socket. */
  78                 if (errno == EAGAIN) {
  79                         DEBUG(10,("read_udp_v4_socket: returned EAGAIN\n"));
  80                 } else {
  81                         DEBUG(2,("read_udp_v4_socket: failed. errno=%s\n",
  82                                 strerror(errno)));
  83                 }
  84                 return 0;
  85         }
  86
  87         if (psa->ss_family != AF_INET) {
  88                 DEBUG(2,("read_udp_v4_socket: invalid address family %d "
  89                         "(not IPv4)\n", (int)psa->ss_family));
  90                 return 0;
  91         }
  92
  93         DEBUG(10,("read_udp_v4_socket: ip %s port %d read: %lu\n",
  94                         inet_ntoa(si->sin_addr),
  95                         si->sin_port,
  96                         (unsigned long)ret));
  97
  98         return ret;
  99 }
 100
 101 /****************************************************************************
 102  Read data from a file descriptor with a timout in msec.
 103  mincount = if timeout, minimum to read before returning
 104  maxcount = number to be read.
 105  time_out = timeout in milliseconds
 106  NB. This can be called with a non-socket fd, don't change
 107  sys_read() to sys_recv() or other socket call.
 108 ****************************************************************************/
 109
 110 NTSTATUS read_fd_with_timeout(int fd, char *buf,
 111                                   size_t mincnt, size_t maxcnt,
 112                                   unsigned int time_out,
 113                                   size_t *size_ret)
 114 {
 115         int pollrtn;
 116         ssize_t readret;
 117         size_t nread = 0;
 118
 119         /* just checking .... */
 120         if (maxcnt <= 0)
 121                 return NT_STATUS_OK;
 122
 123         /* Blocking read */
 124         if (time_out == 0) {
 125                 if (mincnt == 0) {
 126                         mincnt = maxcnt;
 127                 }
 128
 129                 while (nread < mincnt) {
 130                         readret = sys_read(fd, buf + nread, maxcnt - nread);
 131
 132                         if (readret == 0) {
 133                                 DEBUG(5,("read_fd_with_timeout: "
 134                                         "blocking read. EOF from client.\n"));
 135                                 return NT_STATUS_END_OF_FILE;
 136                         }
 137
 138                         if (readret == -1) {
 139                                 return map_nt_error_from_unix(errno);
 140                         }
 141                         nread += readret;
 142                 }
 143                 goto done;
 144         }
 145
 146         /* Most difficult - timeout read */
 147         /* If this is ever called on a disk file and
 148            mincnt is greater then the filesize then
 149            system performance will suffer severely as
 150            select always returns true on disk files */
 151
 152         for (nread=0; nread < mincnt; ) {
 153                 int revents;
 154
 155                 pollrtn = poll_intr_one_fd(fd, POLLIN|POLLHUP, time_out,
 156                                            &revents);
 157
 158                 /* Check if error */
 159                 if (pollrtn == -1) {
 160                         return map_nt_error_from_unix(errno);
 161                 }
 162
 163                 /* Did we timeout ? */
 164                 if ((pollrtn == 0) ||
 165                     ((revents & (POLLIN|POLLHUP|POLLERR)) == 0)) {
 166                         DEBUG(10,("read_fd_with_timeout: timeout read. "
 167                                 "select timed out.\n"));
 168                         return NT_STATUS_IO_TIMEOUT;
 169                 }
 170
 171                 readret = sys_read(fd, buf+nread, maxcnt-nread);
 172
 173                 if (readret == 0) {
 174                         /* we got EOF on the file descriptor */
 175                         DEBUG(5,("read_fd_with_timeout: timeout read. "
 176                                 "EOF from client.\n"));
 177                         return NT_STATUS_END_OF_FILE;
 178                 }
 179
 180                 if (readret == -1) {
 181                         return map_nt_error_from_unix(errno);
 182                 }
 183
 184                 nread += readret;
 185         }
 186
 187  done:
 188         /* Return the number we got */
 189         if (size_ret) {
 190                 *size_ret = nread;
 191         }
 192         return NT_STATUS_OK;
 193 }
 194
 195 /****************************************************************************
 196  Read data from an fd, reading exactly N bytes.
 197  NB. This can be called with a non-socket fd, don't add dependencies
 198  on socket calls.
 199 ****************************************************************************/
 200
 201 NTSTATUS read_data_ntstatus(int fd, char *buffer, size_t N)
 202 {
 203         return read_fd_with_timeout(fd, buffer, N, N, 0, NULL);
 204 }
 205
 206 /****************************************************************************
 207  Send a keepalive packet (rfc1002).
 208 ****************************************************************************/
 209
 210 bool send_keepalive(int client)
 211 {
 212         unsigned char buf[4];
 213
 214         buf[0] = NBSSkeepalive;
 215         buf[1] = buf[2] = buf[3] = 0;
 216
 217         return(write_data(client,(char *)buf,4) == 4);
 218 }
 219
 220 /****************************************************************************
 221  Read 4 bytes of a smb packet and return the smb length of the packet.
 222  Store the result in the buffer.
 223  This version of the function will return a length of zero on receiving
 224  a keepalive packet.
 225  Timeout is in milliseconds.
 226 ****************************************************************************/
 227
 228 NTSTATUS read_smb_length_return_keepalive(int fd, char *inbuf,
 229                                           unsigned int timeout,
 230                                           size_t *len)
 231 {
 232         int msg_type;
 233         NTSTATUS status;
 234
 235         status = read_fd_with_timeout(fd, inbuf, 4, 4, timeout, NULL);
 236
 237         if (!NT_STATUS_IS_OK(status)) {
 238                 return status;
 239         }
 240
 241         *len = smb_len(inbuf);
 242         msg_type = CVAL(inbuf,0);
 243
 244         if (msg_type == NBSSkeepalive) {
 245                 DEBUG(5,("Got keepalive packet\n"));
 246         }
 247
 248         DEBUG(10,("got smb length of %lu\n",(unsigned long)(*len)));
 249
 250         return NT_STATUS_OK;
 251 }
 252
 253 /****************************************************************************
 254  Read an smb from a fd.
 255  The timeout is in milliseconds.
 256  This function will return on receipt of a session keepalive packet.
 257  maxlen is the max number of bytes to return, not including the 4 byte
 258  length. If zero it means buflen limit.
 259  Doesn't check the MAC on signed packets.
 260 ****************************************************************************/
 261
 262 NTSTATUS receive_smb_raw(int fd, char *buffer, size_t buflen, unsigned int timeout,
 263                          size_t maxlen, size_t *p_len)
 264 {
 265         size_t len;
 266         NTSTATUS status;
 267
 268         status = read_smb_length_return_keepalive(fd,buffer,timeout,&len);
 269
 270         if (!NT_STATUS_IS_OK(status)) {
 271                 DEBUG(0, ("read_fd_with_timeout failed, read "
 272                           "error = %s.\n", nt_errstr(status)));
 273                 return status;
 274         }
 275
 276         if (len > buflen) {
 277                 DEBUG(0,("Invalid packet length! (%lu bytes).\n",
 278                                         (unsigned long)len));
 279                 return NT_STATUS_INVALID_PARAMETER;
 280         }
 281
 282         if(len > 0) {
 283                 if (maxlen) {
 284                         len = MIN(len,maxlen);
 285                 }
 286
 287                 status = read_fd_with_timeout(
 288                         fd, buffer+4, len, len, timeout, &len);
 289
 290                 if (!NT_STATUS_IS_OK(status)) {
 291                         DEBUG(0, ("read_fd_with_timeout failed, read error = "
 292                                   "%s.\n", nt_errstr(status)));
 293                         return status;
 294                 }
 295
 296                 /* not all of samba3 properly checks for packet-termination
 297                  * of strings. This ensures that we don't run off into
 298                  * empty space. */
 299                 SSVAL(buffer+4,len, 0);
 300         }
 301
 302         *p_len = len;
 303         return NT_STATUS_OK;
 304 }
 305
 306 /****************************************************************************
 307  Open a socket of the specified type, port, and address for incoming data.
 308 ****************************************************************************/
 309
 310 int open_socket_in(int type,
 311                 uint16_t port,
 312                 int dlevel,
 313                 const struct sockaddr_storage *psock,
 314                 bool rebind)
 315 {
 316         struct sockaddr_storage sock;
 317         int res;
 318         socklen_t slen = sizeof(struct sockaddr_in);
 319
 320         sock = *psock;
 321
 322 #if defined(HAVE_IPV6)
 323         if (sock.ss_family == AF_INET6) {
 324                 ((struct sockaddr_in6 *)&sock)->sin6_port = htons(port);
 325                 slen = sizeof(struct sockaddr_in6);
 326         }
 327 #endif
 328         if (sock.ss_family == AF_INET) {
 329                 ((struct sockaddr_in *)&sock)->sin_port = htons(port);
 330         }
 331
 332         res = socket(sock.ss_family, type, 0 );
 333         if( res == -1 ) {
 334                 if( DEBUGLVL(0) ) {
 335                         dbgtext( "open_socket_in(): socket() call failed: " );
 336                         dbgtext( "%s\n", strerror( errno ) );
 337                 }
 338                 return -1;
 339         }
 340
 341         /* This block sets/clears the SO_REUSEADDR and possibly SO_REUSEPORT. */
 342         {
 343                 int val = rebind ? 1 : 0;
 344                 if( setsockopt(res,SOL_SOCKET,SO_REUSEADDR,
 345                                         (char *)&val,sizeof(val)) == -1 ) {
 346                         if( DEBUGLVL( dlevel ) ) {
 347                                 dbgtext( "open_socket_in(): setsockopt: " );
 348                                 dbgtext( "SO_REUSEADDR = %s ",
 349                                                 val?"true":"false" );
 350                                 dbgtext( "on port %d failed ", port );
 351                                 dbgtext( "with error = %s\n", strerror(errno) );
 352                         }
 353                 }
 354 #ifdef SO_REUSEPORT
 355                 if( setsockopt(res,SOL_SOCKET,SO_REUSEPORT,
 356                                         (char *)&val,sizeof(val)) == -1 ) {
 357                         if( DEBUGLVL( dlevel ) ) {
 358                                 dbgtext( "open_socket_in(): setsockopt: ");
 359                                 dbgtext( "SO_REUSEPORT = %s ",
 360                                                 val?"true":"false");
 361                                 dbgtext( "on port %d failed ", port);
 362                                 dbgtext( "with error = %s\n", strerror(errno));
 363                         }
 364                 }
 365 #endif /* SO_REUSEPORT */
 366         }
 367
 368 #ifdef HAVE_IPV6
 369         /*
 370          * As IPV6_V6ONLY is the default on some systems,
 371          * we better try to be consistent and always use it.
 372          *
 373          * This also avoids using IPv4 via AF_INET6 sockets
 374          * and makes sure %I never resolves to a '::ffff:192.168.0.1'
 375          * string.
 376          */
 377         if (sock.ss_family == AF_INET6) {
 378                 int val = 1;
 379                 int ret;
 380
 381                 ret = setsockopt(res, IPPROTO_IPV6, IPV6_V6ONLY,
 382                                  (const void *)&val, sizeof(val));
 383                 if (ret == -1) {
 384                         if(DEBUGLVL(0)) {
 385                                 dbgtext("open_socket_in(): IPV6_ONLY failed: ");
 386                                 dbgtext("%s\n", strerror(errno));
 387                         }
 388                         close(res);
 389                         return -1;
 390                 }
 391         }
 392 #endif
 393
 394         /* now we've got a socket - we need to bind it */
 395         if (bind(res, (struct sockaddr *)&sock, slen) == -1 ) {
 396                 if( DEBUGLVL(dlevel) && (port == NMB_PORT ||
 397                                          port == NBT_SMB_PORT ||
 398                                          port == TCP_SMB_PORT) ) {
 399                         char addr[INET6_ADDRSTRLEN];
 400                         print_sockaddr(addr, sizeof(addr),
 401                                         &sock);
 402                         dbgtext( "bind failed on port %d ", port);
 403                         dbgtext( "socket_addr = %s.\n", addr);
 404                         dbgtext( "Error = %s\n", strerror(errno));
 405                 }
 406                 close(res);
 407                 return -1;
 408         }
 409
 410         DEBUG( 10, ( "bind succeeded on port %d\n", port ) );
 411         return( res );
 412  }
 413
 414 struct open_socket_out_state {
 415         int fd;
 416         struct tevent_context *ev;
 417         struct sockaddr_storage ss;
 418         socklen_t salen;
 419         uint16_t port;
 420         int wait_usec;
 421         struct tevent_req *connect_subreq;
 422 };
 423
 424 static void open_socket_out_connected(struct tevent_req *subreq);
 425
 426 static void open_socket_out_cleanup(struct tevent_req *req,
 427                                     enum tevent_req_state req_state)
 428 {
 429         struct open_socket_out_state *state =
 430                 tevent_req_data(req, struct open_socket_out_state);
 431
 432         /*
 433          * Make sure that the async_connect_send subreq has a chance to reset
 434          * fcntl before the socket goes away.
 435          */
 436         TALLOC_FREE(state->connect_subreq);
 437
 438         if (req_state == TEVENT_REQ_DONE) {
 439                 /*
 440                  * we keep the socket open for the caller to use
 441                  */
 442                 return;
 443         }
 444
 445         if (state->fd != -1) {
 446                 close(state->fd);
 447                 state->fd = -1;
 448         }
 449 }
 450
 451 /****************************************************************************
 452  Create an outgoing socket. timeout is in milliseconds.
 453 **************************************************************************/
 454
 455 struct tevent_req *open_socket_out_send(TALLOC_CTX *mem_ctx,
 456                                         struct tevent_context *ev,
 457                                         const struct sockaddr_storage *pss,
 458                                         uint16_t port,
 459                                         int timeout)
 460 {
 461         char addr[INET6_ADDRSTRLEN];
 462         struct tevent_req *result;
 463         struct open_socket_out_state *state;
 464         NTSTATUS status;
 465
 466         result = tevent_req_create(mem_ctx, &state,
 467                                    struct open_socket_out_state);
 468         if (result == NULL) {
 469                 return NULL;
 470         }
 471         state->ev = ev;
 472         state->ss = *pss;
 473         state->port = port;
 474         state->wait_usec = 10000;
 475         state->salen = -1;
 476
 477         state->fd = socket(state->ss.ss_family, SOCK_STREAM, 0);
 478         if (state->fd == -1) {
 479                 status = map_nt_error_from_unix(errno);
 480                 goto post_status;
 481         }
 482
 483         tevent_req_set_cleanup_fn(result, open_socket_out_cleanup);
 484
 485         if (!tevent_req_set_endtime(
 486                     result, ev, timeval_current_ofs_msec(timeout))) {
 487                 goto fail;
 488         }
 489
 490 #if defined(HAVE_IPV6)
 491         if (pss->ss_family == AF_INET6) {
 492                 struct sockaddr_in6 *psa6;
 493                 psa6 = (struct sockaddr_in6 *)&state->ss;
 494                 psa6->sin6_port = htons(port);
 495                 if (psa6->sin6_scope_id == 0
 496                     && IN6_IS_ADDR_LINKLOCAL(&psa6->sin6_addr)) {
 497                         setup_linklocal_scope_id(
 498                                 (struct sockaddr *)&(state->ss));
 499                 }
 500                 state->salen = sizeof(struct sockaddr_in6);
 501         }
 502 #endif
 503         if (pss->ss_family == AF_INET) {
 504                 struct sockaddr_in *psa;
 505                 psa = (struct sockaddr_in *)&state->ss;
 506                 psa->sin_port = htons(port);
 507                 state->salen = sizeof(struct sockaddr_in);
 508         }
 509
 510         if (pss->ss_family == AF_UNIX) {
 511                 state->salen = sizeof(struct sockaddr_un);
 512         }
 513
 514         print_sockaddr(addr, sizeof(addr), &state->ss);
 515         DEBUG(3,("Connecting to %s at port %u\n", addr, (unsigned int)port));
 516
 517         state->connect_subreq = async_connect_send(
 518                 state, state->ev, state->fd, (struct sockaddr *)&state->ss,
 519                 state->salen, NULL, NULL, NULL);
 520         if ((state->connect_subreq == NULL)
 521             || !tevent_req_set_endtime(
 522                     state->connect_subreq, state->ev,
 523                     timeval_current_ofs(0, state->wait_usec))) {
 524                 goto fail;
 525         }
 526         tevent_req_set_callback(state->connect_subreq,
 527                                 open_socket_out_connected, result);
 528         return result;
 529
 530  post_status:
 531         tevent_req_nterror(result, status);
 532         return tevent_req_post(result, ev);
 533  fail:
 534         TALLOC_FREE(result);
 535         return NULL;
 536 }
 537
 538 static void open_socket_out_connected(struct tevent_req *subreq)
 539 {
 540         struct tevent_req *req =
 541                 tevent_req_callback_data(subreq, struct tevent_req);
 542         struct open_socket_out_state *state =
 543                 tevent_req_data(req, struct open_socket_out_state);
 544         int ret;
 545         int sys_errno;
 546
 547         ret = async_connect_recv(subreq, &sys_errno);
 548         TALLOC_FREE(subreq);
 549         state->connect_subreq = NULL;
 550         if (ret == 0) {
 551                 tevent_req_done(req);
 552                 return;
 553         }
 554
 555         if (
 556 #ifdef ETIMEDOUT
 557                 (sys_errno == ETIMEDOUT) ||
 558 #endif
 559                 (sys_errno == EINPROGRESS) ||
 560                 (sys_errno == EALREADY) ||
 561                 (sys_errno == EAGAIN)) {
 562
 563                 /*
 564                  * retry
 565                  */
 566
 567                 if (state->wait_usec < 250000) {
 568                         state->wait_usec *= 1.5;
 569                 }
 570
 571                 subreq = async_connect_send(state, state->ev, state->fd,
 572                                             (struct sockaddr *)&state->ss,
 573                                             state->salen, NULL, NULL, NULL);
 574                 if (tevent_req_nomem(subreq, req)) {
 575                         return;
 576                 }
 577                 if (!tevent_req_set_endtime(
 578                             subreq, state->ev,
 579                             timeval_current_ofs_usec(state->wait_usec))) {
 580                         tevent_req_nterror(req, NT_STATUS_NO_MEMORY);
 581                         return;
 582                 }
 583                 tevent_req_set_callback(subreq, open_socket_out_connected, req);
 584                 return;
 585         }
 586
 587 #ifdef EISCONN
 588         if (sys_errno == EISCONN) {
 589                 tevent_req_done(req);
 590                 return;
 591         }
 592 #endif
 593
 594         /* real error */
 595         tevent_req_nterror(req, map_nt_error_from_unix(sys_errno));
 596 }
 597
 598 NTSTATUS open_socket_out_recv(struct tevent_req *req, int *pfd)
 599 {
 600         struct open_socket_out_state *state =
 601                 tevent_req_data(req, struct open_socket_out_state);
 602         NTSTATUS status;
 603
 604         if (tevent_req_is_nterror(req, &status)) {
 605                 return status;
 606         }
 607         *pfd = state->fd;
 608         state->fd = -1;
 609         return NT_STATUS_OK;
 610 }
 611
 612 /**
 613 * @brief open a socket
 614 *
 615 * @param pss a struct sockaddr_storage defining the address to connect to
 616 * @param port to connect to
 617 * @param timeout in MILLISECONDS
 618 * @param pfd file descriptor returned
 619 *
 620 * @return NTSTATUS code
 621 */
 622 NTSTATUS open_socket_out(const struct sockaddr_storage *pss, uint16_t port,
 623                          int timeout, int *pfd)
 624 {
 625         TALLOC_CTX *frame = talloc_stackframe();
 626         struct tevent_context *ev;
 627         struct tevent_req *req;
 628         NTSTATUS status = NT_STATUS_NO_MEMORY;
 629
 630         ev = samba_tevent_context_init(frame);
 631         if (ev == NULL) {
 632                 goto fail;
 633         }
 634
 635         req = open_socket_out_send(frame, ev, pss, port, timeout);
 636         if (req == NULL) {
 637                 goto fail;
 638         }
 639         if (!tevent_req_poll(req, ev)) {
 640                 status = NT_STATUS_INTERNAL_ERROR;
 641                 goto fail;
 642         }
 643         status = open_socket_out_recv(req, pfd);
 644  fail:
 645         TALLOC_FREE(frame);
 646         return status;
 647 }
 648
 649 struct open_socket_out_defer_state {
 650         struct tevent_context *ev;
 651         struct sockaddr_storage ss;
 652         uint16_t port;
 653         int timeout;
 654         int fd;
 655 };
 656
 657 static void open_socket_out_defer_waited(struct tevent_req *subreq);
 658 static void open_socket_out_defer_connected(struct tevent_req *subreq);
 659
 660 struct tevent_req *open_socket_out_defer_send(TALLOC_CTX *mem_ctx,
 661                                               struct tevent_context *ev,
 662                                               struct timeval wait_time,
 663                                               const struct sockaddr_storage *pss,
 664                                               uint16_t port,
 665                                               int timeout)
 666 {
 667         struct tevent_req *req, *subreq;
 668         struct open_socket_out_defer_state *state;
 669
 670         req = tevent_req_create(mem_ctx, &state,
 671                                 struct open_socket_out_defer_state);
 672         if (req == NULL) {
 673                 return NULL;
 674         }
 675         state->ev = ev;
 676         state->ss = *pss;
 677         state->port = port;
 678         state->timeout = timeout;
 679
 680         subreq = tevent_wakeup_send(
 681                 state, ev,
 682                 timeval_current_ofs(wait_time.tv_sec, wait_time.tv_usec));
 683         if (subreq == NULL) {
 684                 goto fail;
 685         }
 686         tevent_req_set_callback(subreq, open_socket_out_defer_waited, req);
 687         return req;
 688  fail:
 689         TALLOC_FREE(req);
 690         return NULL;
 691 }
 692
 693 static void open_socket_out_defer_waited(struct tevent_req *subreq)
 694 {
 695         struct tevent_req *req = tevent_req_callback_data(
 696                 subreq, struct tevent_req);
 697         struct open_socket_out_defer_state *state = tevent_req_data(
 698                 req, struct open_socket_out_defer_state);
 699         bool ret;
 700
 701         ret = tevent_wakeup_recv(subreq);
 702         TALLOC_FREE(subreq);
 703         if (!ret) {
 704                 tevent_req_nterror(req, NT_STATUS_INTERNAL_ERROR);
 705                 return;
 706         }
 707
 708         subreq = open_socket_out_send(state, state->ev, &state->ss,
 709                                       state->port, state->timeout);
 710         if (tevent_req_nomem(subreq, req)) {
 711                 return;
 712         }
 713         tevent_req_set_callback(subreq, open_socket_out_defer_connected, req);
 714 }
 715
 716 static void open_socket_out_defer_connected(struct tevent_req *subreq)
 717 {
 718         struct tevent_req *req = tevent_req_callback_data(
 719                 subreq, struct tevent_req);
 720         struct open_socket_out_defer_state *state = tevent_req_data(
 721                 req, struct open_socket_out_defer_state);
 722         NTSTATUS status;
 723
 724         status = open_socket_out_recv(subreq, &state->fd);
 725         TALLOC_FREE(subreq);
 726         if (!NT_STATUS_IS_OK(status)) {
 727                 tevent_req_nterror(req, status);
 728                 return;
 729         }
 730         tevent_req_done(req);
 731 }
 732
 733 NTSTATUS open_socket_out_defer_recv(struct tevent_req *req, int *pfd)
 734 {
 735         struct open_socket_out_defer_state *state = tevent_req_data(
 736                 req, struct open_socket_out_defer_state);
 737         NTSTATUS status;
 738
 739         if (tevent_req_is_nterror(req, &status)) {
 740                 return status;
 741         }
 742         *pfd = state->fd;
 743         state->fd = -1;
 744         return NT_STATUS_OK;
 745 }
 746
 747 /****************************************************************************
 748  Open a connected UDP socket to host on port
 749 **************************************************************************/
 750
 751 int open_udp_socket(const char *host, int port)
 752 {
 753         struct sockaddr_storage ss;
 754         int res;
 755         socklen_t salen;
 756
 757         if (!interpret_string_addr(&ss, host, 0)) {
 758                 DEBUG(10,("open_udp_socket: can't resolve name %s\n",
 759                         host));
 760                 return -1;
 761         }
 762
 763         res = socket(ss.ss_family, SOCK_DGRAM, 0);
 764         if (res == -1) {
 765                 return -1;
 766         }
 767
 768 #if defined(HAVE_IPV6)
 769         if (ss.ss_family == AF_INET6) {
 770                 struct sockaddr_in6 *psa6;
 771                 psa6 = (struct sockaddr_in6 *)&ss;
 772                 psa6->sin6_port = htons(port);
 773                 if (psa6->sin6_scope_id == 0
 774                                 && IN6_IS_ADDR_LINKLOCAL(&psa6->sin6_addr)) {
 775                         setup_linklocal_scope_id(
 776                                 (struct sockaddr *)&ss);
 777                 }
 778                 salen = sizeof(struct sockaddr_in6);
 779         } else
 780 #endif
 781         if (ss.ss_family == AF_INET) {
 782                 struct sockaddr_in *psa;
 783                 psa = (struct sockaddr_in *)&ss;
 784                 psa->sin_port = htons(port);
 785             salen = sizeof(struct sockaddr_in);
 786         } else {
 787                 DEBUG(1, ("unknown socket family %d", ss.ss_family));
 788                 close(res);
 789                 return -1;
 790         }
 791
 792         if (connect(res, (struct sockaddr *)&ss, salen)) {
 793                 close(res);
 794                 return -1;
 795         }
 796
 797         return res;
 798 }
 799
 800 /*******************************************************************
 801  Return the IP addr of the remote end of a socket as a string.
 802  Optionally return the struct sockaddr_storage.
 803  ******************************************************************/
 804
 805 static const char *get_peer_addr_internal(int fd,
 806                                 char *addr_buf,
 807                                 size_t addr_buf_len,
 808                                 struct sockaddr *pss,
 809                                 socklen_t *plength)
 810 {
 811         struct sockaddr_storage ss;
 812         socklen_t length = sizeof(ss);
 813
 814         strlcpy(addr_buf,"0.0.0.0",addr_buf_len);
 815
 816         if (fd == -1) {
 817                 return addr_buf;
 818         }
 819
 820         if (pss == NULL) {
 821                 pss = (struct sockaddr *)&ss;
 822                 plength = &length;
 823         }
 824
 825         if (getpeername(fd, (struct sockaddr *)pss, plength) < 0) {
 826                 int level = (errno == ENOTCONN) ? 2 : 0;
 827                 DEBUG(level, ("getpeername failed. Error was %s\n",
 828                                strerror(errno)));
 829                 return addr_buf;
 830         }
 831
 832         print_sockaddr_len(addr_buf,
 833                         addr_buf_len,
 834                         pss,
 835                         *plength);
 836         return addr_buf;
 837 }
 838
 839 /*******************************************************************
 840  Matchname - determine if host name matches IP address. Used to
 841  confirm a hostname lookup to prevent spoof attacks.
 842 ******************************************************************/
 843
 844 static bool matchname(const char *remotehost,
 845                 const struct sockaddr *pss,
 846                 socklen_t len)
 847 {
 848         struct addrinfo *res = NULL;
 849         struct addrinfo *ailist = NULL;
 850         char addr_buf[INET6_ADDRSTRLEN];
 851         bool ret = interpret_string_addr_internal(&ailist,
 852                         remotehost,
 853                         AI_ADDRCONFIG|AI_CANONNAME);
 854
 855         if (!ret || ailist == NULL) {
 856                 DEBUG(3,("matchname: getaddrinfo failed for "
 857                         "name %s [%s]\n",
 858                         remotehost,
 859                         gai_strerror(ret) ));
 860                 return false;
 861         }
 862
 863         /*
 864          * Make sure that getaddrinfo() returns the "correct" host name.
 865          */
 866
 867         if (ailist->ai_canonname == NULL ||
 868                 (!strequal(remotehost, ailist->ai_canonname) &&
 869                  !strequal(remotehost, "localhost"))) {
 870                 DEBUG(0,("matchname: host name/name mismatch: %s != %s\n",
 871                          remotehost,
 872                          ailist->ai_canonname ?
 873                                  ailist->ai_canonname : "(NULL)"));
 874                 freeaddrinfo(ailist);
 875                 return false;
 876         }
 877
 878         /* Look up the host address in the address list we just got. */
 879         for (res = ailist; res; res = res->ai_next) {
 880                 if (!res->ai_addr) {
 881                         continue;
 882                 }
 883                 if (sockaddr_equal((const struct sockaddr *)res->ai_addr,
 884                                         (const struct sockaddr *)pss)) {
 885                         freeaddrinfo(ailist);
 886                         return true;
 887                 }
 888         }
 889
 890         /*
 891          * The host name does not map to the original host address. Perhaps
 892          * someone has compromised a name server. More likely someone botched
 893          * it, but that could be dangerous, too.
 894          */
 895
 896         DEBUG(0,("matchname: host name/address mismatch: %s != %s\n",
 897                 print_sockaddr_len(addr_buf,
 898                         sizeof(addr_buf),
 899                         pss,
 900                         len),
 901                  ailist->ai_canonname ? ailist->ai_canonname : "(NULL)"));
 902
 903         if (ailist) {
 904                 freeaddrinfo(ailist);
 905         }
 906         return false;
 907 }
 908
 909 /*******************************************************************
 910  Deal with the singleton cache.
 911 ******************************************************************/
 912
 913 struct name_addr_pair {
 914         struct sockaddr_storage ss;
 915         const char *name;
 916 };
 917
 918 /*******************************************************************
 919  Lookup a name/addr pair. Returns memory allocated from memcache.
 920 ******************************************************************/
 921
 922 static bool lookup_nc(struct name_addr_pair *nc)
 923 {
 924         DATA_BLOB tmp;
 925
 926         ZERO_STRUCTP(nc);
 927
 928         if (!memcache_lookup(
 929                         NULL, SINGLETON_CACHE,
 930                         data_blob_string_const_null("get_peer_name"),
 931                         &tmp)) {
 932                 return false;
 933         }
 934
 935         memcpy(&nc->ss, tmp.data, sizeof(nc->ss));
 936         nc->name = (const char *)tmp.data + sizeof(nc->ss);
 937         return true;
 938 }
 939
 940 /*******************************************************************
 941  Save a name/addr pair.
 942 ******************************************************************/
 943
 944 static void store_nc(const struct name_addr_pair *nc)
 945 {
 946         DATA_BLOB tmp;
 947         size_t namelen = strlen(nc->name);
 948
 949         tmp = data_blob(NULL, sizeof(nc->ss) + namelen + 1);
 950         if (!tmp.data) {
 951                 return;
 952         }
 953         memcpy(tmp.data, &nc->ss, sizeof(nc->ss));
 954         memcpy(tmp.data+sizeof(nc->ss), nc->name, namelen+1);
 955
 956         memcache_add(NULL, SINGLETON_CACHE,
 957                         data_blob_string_const_null("get_peer_name"),
 958                         tmp);
 959         data_blob_free(&tmp);
 960 }
 961
 962 /*******************************************************************
 963  Return the IP addr of the remote end of a socket as a string.
 964  ******************************************************************/
 965
 966 const char *get_peer_addr(int fd, char *addr, size_t addr_len)
 967 {
 968         return get_peer_addr_internal(fd, addr, addr_len, NULL, NULL);
 969 }
 970
 971 int get_remote_hostname(const struct tsocket_address *remote_address,
 972                         char **name,
 973                         TALLOC_CTX *mem_ctx)
 974 {
 975         char name_buf[MAX_DNS_NAME_LENGTH];
 976         char tmp_name[MAX_DNS_NAME_LENGTH];
 977         struct name_addr_pair nc;
 978         struct sockaddr_storage ss;
 979         ssize_t len;
 980         int rc;
 981
 982         if (!lp_hostname_lookups()) {
 983                 nc.name = tsocket_address_inet_addr_string(remote_address,
 984                                                            mem_ctx);
 985                 if (nc.name == NULL) {
 986                         return -1;
 987                 }
 988
 989                 len = tsocket_address_bsd_sockaddr(remote_address,
 990                                                    (struct sockaddr *) &nc.ss,
 991                                                    sizeof(struct sockaddr_storage));
 992                 if (len < 0) {
 993                         return -1;
 994                 }
 995
 996                 store_nc(&nc);
 997                 lookup_nc(&nc);
 998
 999                 if (nc.name == NULL) {
1000                         *name = talloc_strdup(mem_ctx, "UNKNOWN");
1001                 } else {
1002                         *name = talloc_strdup(mem_ctx, nc.name);
1003                 }
1004                 return 0;
1005         }
1006
1007         lookup_nc(&nc);
1008
1009         ZERO_STRUCT(ss);
1010
1011         len = tsocket_address_bsd_sockaddr(remote_address,
1012                                            (struct sockaddr *) &ss,
1013                                            sizeof(struct sockaddr_storage));
1014         if (len < 0) {
1015                 return -1;
1016         }
1017
1018         /* it might be the same as the last one - save some DNS work */
1019         if (sockaddr_equal((struct sockaddr *)&ss, (struct sockaddr *)&nc.ss)) {
1020                 if (nc.name == NULL) {
1021                         *name = talloc_strdup(mem_ctx, "UNKNOWN");
1022                 } else {
1023                         *name = talloc_strdup(mem_ctx, nc.name);
1024                 }
1025                 return 0;
1026         }
1027
1028         /* Look up the remote host name. */
1029         rc = sys_getnameinfo((struct sockaddr *) &ss,
1030                              len,
1031                              name_buf,
1032                              sizeof(name_buf),
1033                              NULL,
1034                              0,
1035                              0);
1036         if (rc < 0) {
1037                 char *p;
1038
1039                 p = tsocket_address_inet_addr_string(remote_address, mem_ctx);
1040                 if (p == NULL) {
1041                         return -1;
1042                 }
1043
1044                 DEBUG(1,("getnameinfo failed for %s with error %s\n",
1045                          p,
1046                          gai_strerror(rc)));
1047                 strlcpy(name_buf, p, sizeof(name_buf));
1048
1049                 TALLOC_FREE(p);
1050         } else {
1051                 if (!matchname(name_buf, (struct sockaddr *)&ss, len)) {
1052                         DEBUG(0,("matchname failed on %s\n", name_buf));
1053                         strlcpy(name_buf, "UNKNOWN", sizeof(name_buf));
1054                 }
1055         }
1056
1057         strlcpy(tmp_name, name_buf, sizeof(tmp_name));
1058         alpha_strcpy(name_buf, tmp_name, "_-.", sizeof(name_buf));
1059         if (strstr(name_buf,"..")) {
1060                 strlcpy(name_buf, "UNKNOWN", sizeof(name_buf));
1061         }
1062
1063         nc.name = name_buf;
1064         nc.ss = ss;
1065
1066         store_nc(&nc);
1067         lookup_nc(&nc);
1068
1069         if (nc.name == NULL) {
1070                 *name = talloc_strdup(mem_ctx, "UNKOWN");
1071         } else {
1072                 *name = talloc_strdup(mem_ctx, nc.name);
1073         }
1074
1075         return 0;
1076 }
1077
1078 /*******************************************************************
1079  Create protected unix domain socket.
1080
1081  Some unixes cannot set permissions on a ux-dom-sock, so we
1082  have to make sure that the directory contains the protection
1083  permissions instead.
1084  ******************************************************************/
1085
1086 int create_pipe_sock(const char *socket_dir,
1087                      const char *socket_name,
1088                      mode_t dir_perms)
1089 {
1090 #ifdef HAVE_UNIXSOCKET
1091         struct sockaddr_un sunaddr;
1092         bool ok;
1093         int sock = -1;
1094         mode_t old_umask;
1095         char *path = NULL;
1096
1097         old_umask = umask(0);
1098
1099         ok = directory_create_or_exist_strict(socket_dir,
1100                                               sec_initial_uid(),
1101                                               dir_perms);
1102         if (!ok) {
1103                 goto out_close;
1104         }
1105
1106         /* Create the socket file */
1107         sock = socket(AF_UNIX, SOCK_STREAM, 0);
1108
1109         if (sock == -1) {
1110                 DEBUG(0, ("create_pipe_sock: socket error %s\n",
1111                         strerror(errno) ));
1112                 goto out_close;
1113         }
1114
1115         if (asprintf(&path, "%s/%s", socket_dir, socket_name) == -1) {
1116                 goto out_close;
1117         }
1118
1119         unlink(path);
1120         memset(&sunaddr, 0, sizeof(sunaddr));
1121         sunaddr.sun_family = AF_UNIX;
1122         strlcpy(sunaddr.sun_path, path, sizeof(sunaddr.sun_path));
1123
1124         if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) == -1) {
1125                 DEBUG(0, ("bind failed on pipe socket %s: %s\n", path,
1126                         strerror(errno)));
1127                 goto out_close;
1128         }
1129
1130         SAFE_FREE(path);
1131
1132         umask(old_umask);
1133         return sock;
1134
1135 out_close:
1136         SAFE_FREE(path);
1137         if (sock != -1)
1138                 close(sock);
1139
1140         umask(old_umask);
1141         return -1;
1142
1143 #else
1144         DEBUG(0, ("create_pipe_sock: No Unix sockets on this system\n"));
1145         return -1;
1146 #endif /* HAVE_UNIXSOCKET */
1147 }
1148
1149 /****************************************************************************
1150  Get my own canonical name, including domain.
1151 ****************************************************************************/
1152
1153 const char *get_mydnsfullname(void)
1154 {
1155         struct addrinfo *res = NULL;
1156         char my_hostname[HOST_NAME_MAX];
1157         bool ret;
1158         DATA_BLOB tmp;
1159
1160         if (memcache_lookup(NULL, SINGLETON_CACHE,
1161                         data_blob_string_const_null("get_mydnsfullname"),
1162                         &tmp)) {
1163                 SMB_ASSERT(tmp.length > 0);
1164                 return (const char *)tmp.data;
1165         }
1166
1167         /* get my host name */
1168         if (gethostname(my_hostname, sizeof(my_hostname)) == -1) {
1169                 DEBUG(0,("get_mydnsfullname: gethostname failed\n"));
1170                 return NULL;
1171         }
1172
1173         /* Ensure null termination. */
1174         my_hostname[sizeof(my_hostname)-1] = '\0';
1175
1176         ret = interpret_string_addr_internal(&res,
1177                                 my_hostname,
1178                                 AI_ADDRCONFIG|AI_CANONNAME);
1179
1180         if (!ret || res == NULL) {
1181                 DEBUG(3,("get_mydnsfullname: getaddrinfo failed for "
1182                         "name %s [%s]\n",
1183                         my_hostname,
1184                         gai_strerror(ret) ));
1185                 return NULL;
1186         }
1187
1188         /*
1189          * Make sure that getaddrinfo() returns the "correct" host name.
1190          */
1191
1192         if (res->ai_canonname == NULL) {
1193                 DEBUG(3,("get_mydnsfullname: failed to get "
1194                         "canonical name for %s\n",
1195                         my_hostname));
1196                 freeaddrinfo(res);
1197                 return NULL;
1198         }
1199
1200         /* This copies the data, so we must do a lookup
1201          * afterwards to find the value to return.
1202          */
1203
1204         memcache_add(NULL, SINGLETON_CACHE,
1205                         data_blob_string_const_null("get_mydnsfullname"),
1206                         data_blob_string_const_null(res->ai_canonname));
1207
1208         if (!memcache_lookup(NULL, SINGLETON_CACHE,
1209                         data_blob_string_const_null("get_mydnsfullname"),
1210                         &tmp)) {
1211                 tmp = data_blob_talloc(talloc_tos(), res->ai_canonname,
1212                                 strlen(res->ai_canonname) + 1);
1213         }
1214
1215         freeaddrinfo(res);
1216
1217         return (const char *)tmp.data;
1218 }
1219
1220 /************************************************************
1221  Is this my ip address ?
1222 ************************************************************/
1223
1224 static bool is_my_ipaddr(const char *ipaddr_str)
1225 {
1226         struct sockaddr_storage ss;
1227         struct iface_struct *nics;
1228         int i, n;
1229
1230         if (!interpret_string_addr(&ss, ipaddr_str, AI_NUMERICHOST)) {
1231                 return false;
1232         }
1233
1234         if (is_zero_addr(&ss)) {
1235                 return false;
1236         }
1237
1238         if (ismyaddr((struct sockaddr *)&ss) ||
1239                         is_loopback_addr((struct sockaddr *)&ss)) {
1240                 return true;
1241         }
1242
1243         n = get_interfaces(talloc_tos(), &nics);
1244         for (i=0; i<n; i++) {
1245                 if (sockaddr_equal((struct sockaddr *)&nics[i].ip, (struct sockaddr *)&ss)) {
1246                         TALLOC_FREE(nics);
1247                         return true;
1248                 }
1249         }
1250         TALLOC_FREE(nics);
1251         return false;
1252 }
1253
1254 /************************************************************
1255  Is this my name ?
1256 ************************************************************/
1257
1258 bool is_myname_or_ipaddr(const char *s)
1259 {
1260         TALLOC_CTX *ctx = talloc_tos();
1261         char *name = NULL;
1262         const char *dnsname;
1263         char *servername = NULL;
1264
1265         if (!s) {
1266                 return false;
1267         }
1268
1269         /* Santize the string from '\\name' */
1270         name = talloc_strdup(ctx, s);
1271         if (!name) {
1272                 return false;
1273         }
1274
1275         servername = strrchr_m(name, '\\' );
1276         if (!servername) {
1277                 servername = name;
1278         } else {
1279                 servername++;
1280         }
1281
1282         /* Optimize for the common case */
1283         if (strequal(servername, lp_netbios_name())) {
1284                 return true;
1285         }
1286
1287         /* Check for an alias */
1288         if (is_myname(servername)) {
1289                 return true;
1290         }
1291
1292         /* Check for loopback */
1293         if (strequal(servername, "127.0.0.1") ||
1294                         strequal(servername, "::1")) {
1295                 return true;
1296         }
1297
1298         if (strequal(servername, "localhost")) {
1299                 return true;
1300         }
1301
1302         /* Maybe it's my dns name */
1303         dnsname = get_mydnsfullname();
1304         if (dnsname && strequal(servername, dnsname)) {
1305                 return true;
1306         }
1307
1308         /* Maybe its an IP address? */
1309         if (is_ipaddress(servername)) {
1310                 return is_my_ipaddr(servername);
1311         }
1312
1313         /* Handle possible CNAME records - convert to an IP addr. list. */
1314         {
1315                 /* Use DNS to resolve the name, check all addresses. */
1316                 struct addrinfo *p = NULL;
1317                 struct addrinfo *res = NULL;
1318
1319                 if (!interpret_string_addr_internal(&res,
1320                                 servername,
1321                                 AI_ADDRCONFIG)) {
1322                         return false;
1323                 }
1324
1325                 for (p = res; p; p = p->ai_next) {
1326                         char addr[INET6_ADDRSTRLEN];
1327                         struct sockaddr_storage ss;
1328
1329                         ZERO_STRUCT(ss);
1330                         memcpy(&ss, p->ai_addr, p->ai_addrlen);
1331                         print_sockaddr(addr,
1332                                         sizeof(addr),
1333                                         &ss);
1334                         if (is_my_ipaddr(addr)) {
1335                                 freeaddrinfo(res);
1336                                 return true;
1337                         }
1338                 }
1339                 freeaddrinfo(res);
1340         }
1341
1342         /* No match */
1343         return false;
1344 }
1345
1346 struct getaddrinfo_state {
1347         const char *node;
1348         const char *service;
1349         const struct addrinfo *hints;
1350         struct addrinfo *res;
1351         int ret;
1352 };
1353
1354 static void getaddrinfo_do(void *private_data);
1355 static void getaddrinfo_done(struct tevent_req *subreq);
1356
1357 struct tevent_req *getaddrinfo_send(TALLOC_CTX *mem_ctx,
1358                                     struct tevent_context *ev,
1359                                     struct fncall_context *ctx,
1360                                     const char *node,
1361                                     const char *service,
1362                                     const struct addrinfo *hints)
1363 {
1364         struct tevent_req *req, *subreq;
1365         struct getaddrinfo_state *state;
1366
1367         req = tevent_req_create(mem_ctx, &state, struct getaddrinfo_state);
1368         if (req == NULL) {
1369                 return NULL;
1370         }
1371
1372         state->node = node;
1373         state->service = service;
1374         state->hints = hints;
1375
1376         subreq = fncall_send(state, ev, ctx, getaddrinfo_do, state);
1377         if (tevent_req_nomem(subreq, req)) {
1378                 return tevent_req_post(req, ev);
1379         }
1380         tevent_req_set_callback(subreq, getaddrinfo_done, req);
1381         return req;
1382 }
1383
1384 static void getaddrinfo_do(void *private_data)
1385 {
1386         struct getaddrinfo_state *state =
1387                 talloc_get_type_abort(private_data, struct getaddrinfo_state);
1388
1389         state->ret = getaddrinfo(state->node, state->service, state->hints,
1390                                  &state->res);
1391 }
1392
1393 static void getaddrinfo_done(struct tevent_req *subreq)
1394 {
1395         struct tevent_req *req = tevent_req_callback_data(
1396                 subreq, struct tevent_req);
1397         int ret, err;
1398
1399         ret = fncall_recv(subreq, &err);
1400         TALLOC_FREE(subreq);
1401         if (ret == -1) {
1402                 tevent_req_error(req, err);
1403                 return;
1404         }
1405         tevent_req_done(req);
1406 }
1407
1408 int getaddrinfo_recv(struct tevent_req *req, struct addrinfo **res)
1409 {
1410         struct getaddrinfo_state *state = tevent_req_data(
1411                 req, struct getaddrinfo_state);
1412         int err;
1413
1414         if (tevent_req_is_unix_error(req, &err)) {
1415                 switch(err) {
1416                 case ENOMEM:
1417                         return EAI_MEMORY;
1418                 default:
1419                         return EAI_FAIL;
1420                 }
1421         }
1422         if (state->ret == 0) {
1423                 *res = state->res;
1424         }
1425         return state->ret;
1426 }
1427
1428 int poll_one_fd(int fd, int events, int timeout, int *revents)
1429 {
1430         struct pollfd pfd;
1431         int ret;
1432
1433         pfd.fd = fd;
1434         pfd.events = events;
1435
1436         ret = poll(&pfd, 1, timeout);
1437
1438         /*
1439          * Assign whatever poll did, even in the ret<=0 case.
1440          */
1441         *revents = pfd.revents;
1442
1443         return ret;
1444 }
1445
1446 int poll_intr_one_fd(int fd, int events, int timeout, int *revents)
1447 {
1448         struct pollfd pfd;
1449         int ret;
1450
1451         pfd.fd = fd;
1452         pfd.events = events;
1453
1454         ret = sys_poll_intr(&pfd, 1, timeout);
1455         if (ret <= 0) {
1456                 *revents = 0;
1457                 return ret;
1458         }
1459         *revents = pfd.revents;
1460         return 1;
1461 }