1 /* 2 * os-win32.c 3 * 4 * Copyright (c) 2003-2008 Fabrice Bellard 5 * Copyright (c) 2010-2016 Red Hat, Inc. 6 * 7 * QEMU library functions for win32 which are shared between QEMU and 8 * the QEMU tools. 9 * 10 * Permission is hereby granted, free of charge, to any person obtaining a copy 11 * of this software and associated documentation files (the "Software"), to deal 12 * in the Software without restriction, including without limitation the rights 13 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 14 * copies of the Software, and to permit persons to whom the Software is 15 * furnished to do so, subject to the following conditions: 16 * 17 * The above copyright notice and this permission notice shall be included in 18 * all copies or substantial portions of the Software. 19 * 20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 21 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 23 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 24 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 25 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 26 * THE SOFTWARE. 27 * 28 * The implementation of g_poll (functions poll_rest, g_poll) at the end of 29 * this file are based on code from GNOME glib-2 and use a different license, 30 * see the license comment there. 31 */ 32 #include "qemu/osdep.h" 33 #include <windows.h> 34 #include <glib.h> 35 #include "qapi/error.h" 36 #include "sysemu/sysemu.h" 37 #include "qemu/main-loop.h" 38 #include "trace.h" 39 #include "qemu/sockets.h" 40 #include "qemu/cutils.h" 41 42 /* this must come after including "trace.h" */ 43 #include <shlobj.h> 44 45 void *qemu_oom_check(void *ptr) 46 { 47 if (ptr == NULL) { 48 fprintf(stderr, "Failed to allocate memory: %lu\n", GetLastError()); 49 abort(); 50 } 51 return ptr; 52 } 53 54 void *qemu_try_memalign(size_t alignment, size_t size) 55 { 56 void *ptr; 57 58 if (!size) { 59 abort(); 60 } 61 ptr = VirtualAlloc(NULL, size, MEM_COMMIT, PAGE_READWRITE); 62 trace_qemu_memalign(alignment, size, ptr); 63 return ptr; 64 } 65 66 void *qemu_memalign(size_t alignment, size_t size) 67 { 68 return qemu_oom_check(qemu_try_memalign(alignment, size)); 69 } 70 71 void *qemu_anon_ram_alloc(size_t size, uint64_t *align) 72 { 73 void *ptr; 74 75 /* FIXME: this is not exactly optimal solution since VirtualAlloc 76 has 64Kb granularity, but at least it guarantees us that the 77 memory is page aligned. */ 78 ptr = VirtualAlloc(NULL, size, MEM_COMMIT, PAGE_READWRITE); 79 trace_qemu_anon_ram_alloc(size, ptr); 80 return ptr; 81 } 82 83 void qemu_vfree(void *ptr) 84 { 85 trace_qemu_vfree(ptr); 86 if (ptr) { 87 VirtualFree(ptr, 0, MEM_RELEASE); 88 } 89 } 90 91 void qemu_anon_ram_free(void *ptr, size_t size) 92 { 93 trace_qemu_anon_ram_free(ptr, size); 94 if (ptr) { 95 VirtualFree(ptr, 0, MEM_RELEASE); 96 } 97 } 98 99 #ifndef CONFIG_LOCALTIME_R 100 /* FIXME: add proper locking */ 101 struct tm *gmtime_r(const time_t *timep, struct tm *result) 102 { 103 struct tm *p = gmtime(timep); 104 memset(result, 0, sizeof(*result)); 105 if (p) { 106 *result = *p; 107 p = result; 108 } 109 return p; 110 } 111 112 /* FIXME: add proper locking */ 113 struct tm *localtime_r(const time_t *timep, struct tm *result) 114 { 115 struct tm *p = localtime(timep); 116 memset(result, 0, sizeof(*result)); 117 if (p) { 118 *result = *p; 119 p = result; 120 } 121 return p; 122 } 123 #endif /* CONFIG_LOCALTIME_R */ 124 125 void qemu_set_block(int fd) 126 { 127 unsigned long opt = 0; 128 WSAEventSelect(fd, NULL, 0); 129 ioctlsocket(fd, FIONBIO, &opt); 130 } 131 132 void qemu_set_nonblock(int fd) 133 { 134 unsigned long opt = 1; 135 ioctlsocket(fd, FIONBIO, &opt); 136 qemu_fd_register(fd); 137 } 138 139 int socket_set_fast_reuse(int fd) 140 { 141 /* Enabling the reuse of an endpoint that was used by a socket still in 142 * TIME_WAIT state is usually performed by setting SO_REUSEADDR. On Windows 143 * fast reuse is the default and SO_REUSEADDR does strange things. So we 144 * don't have to do anything here. More info can be found at: 145 * http://msdn.microsoft.com/en-us/library/windows/desktop/ms740621.aspx */ 146 return 0; 147 } 148 149 150 static int socket_error(void) 151 { 152 switch (WSAGetLastError()) { 153 case 0: 154 return 0; 155 case WSAEINTR: 156 return EINTR; 157 case WSAEINVAL: 158 return EINVAL; 159 case WSA_INVALID_HANDLE: 160 return EBADF; 161 case WSA_NOT_ENOUGH_MEMORY: 162 return ENOMEM; 163 case WSA_INVALID_PARAMETER: 164 return EINVAL; 165 case WSAENAMETOOLONG: 166 return ENAMETOOLONG; 167 case WSAENOTEMPTY: 168 return ENOTEMPTY; 169 case WSAEWOULDBLOCK: 170 /* not using EWOULDBLOCK as we don't want code to have 171 * to check both EWOULDBLOCK and EAGAIN */ 172 return EAGAIN; 173 case WSAEINPROGRESS: 174 return EINPROGRESS; 175 case WSAEALREADY: 176 return EALREADY; 177 case WSAENOTSOCK: 178 return ENOTSOCK; 179 case WSAEDESTADDRREQ: 180 return EDESTADDRREQ; 181 case WSAEMSGSIZE: 182 return EMSGSIZE; 183 case WSAEPROTOTYPE: 184 return EPROTOTYPE; 185 case WSAENOPROTOOPT: 186 return ENOPROTOOPT; 187 case WSAEPROTONOSUPPORT: 188 return EPROTONOSUPPORT; 189 case WSAEOPNOTSUPP: 190 return EOPNOTSUPP; 191 case WSAEAFNOSUPPORT: 192 return EAFNOSUPPORT; 193 case WSAEADDRINUSE: 194 return EADDRINUSE; 195 case WSAEADDRNOTAVAIL: 196 return EADDRNOTAVAIL; 197 case WSAENETDOWN: 198 return ENETDOWN; 199 case WSAENETUNREACH: 200 return ENETUNREACH; 201 case WSAENETRESET: 202 return ENETRESET; 203 case WSAECONNABORTED: 204 return ECONNABORTED; 205 case WSAECONNRESET: 206 return ECONNRESET; 207 case WSAENOBUFS: 208 return ENOBUFS; 209 case WSAEISCONN: 210 return EISCONN; 211 case WSAENOTCONN: 212 return ENOTCONN; 213 case WSAETIMEDOUT: 214 return ETIMEDOUT; 215 case WSAECONNREFUSED: 216 return ECONNREFUSED; 217 case WSAELOOP: 218 return ELOOP; 219 case WSAEHOSTUNREACH: 220 return EHOSTUNREACH; 221 default: 222 return EIO; 223 } 224 } 225 226 int inet_aton(const char *cp, struct in_addr *ia) 227 { 228 uint32_t addr = inet_addr(cp); 229 if (addr == 0xffffffff) { 230 return 0; 231 } 232 ia->s_addr = addr; 233 return 1; 234 } 235 236 void qemu_set_cloexec(int fd) 237 { 238 } 239 240 /* Offset between 1/1/1601 and 1/1/1970 in 100 nanosec units */ 241 #define _W32_FT_OFFSET (116444736000000000ULL) 242 243 int qemu_gettimeofday(qemu_timeval *tp) 244 { 245 union { 246 unsigned long long ns100; /*time since 1 Jan 1601 in 100ns units */ 247 FILETIME ft; 248 } _now; 249 250 if(tp) { 251 GetSystemTimeAsFileTime (&_now.ft); 252 tp->tv_usec=(long)((_now.ns100 / 10ULL) % 1000000ULL ); 253 tp->tv_sec= (long)((_now.ns100 - _W32_FT_OFFSET) / 10000000ULL); 254 } 255 /* Always return 0 as per Open Group Base Specifications Issue 6. 256 Do not set errno on error. */ 257 return 0; 258 } 259 260 int qemu_get_thread_id(void) 261 { 262 return GetCurrentThreadId(); 263 } 264 265 char * 266 qemu_get_local_state_pathname(const char *relative_pathname) 267 { 268 HRESULT result; 269 char base_path[MAX_PATH+1] = ""; 270 271 result = SHGetFolderPath(NULL, CSIDL_COMMON_APPDATA, NULL, 272 /* SHGFP_TYPE_CURRENT */ 0, base_path); 273 if (result != S_OK) { 274 /* misconfigured environment */ 275 g_critical("CSIDL_COMMON_APPDATA unavailable: %ld", (long)result); 276 abort(); 277 } 278 return g_strdup_printf("%s" G_DIR_SEPARATOR_S "%s", base_path, 279 relative_pathname); 280 } 281 282 void qemu_set_tty_echo(int fd, bool echo) 283 { 284 HANDLE handle = (HANDLE)_get_osfhandle(fd); 285 DWORD dwMode = 0; 286 287 if (handle == INVALID_HANDLE_VALUE) { 288 return; 289 } 290 291 GetConsoleMode(handle, &dwMode); 292 293 if (echo) { 294 SetConsoleMode(handle, dwMode | ENABLE_ECHO_INPUT | ENABLE_LINE_INPUT); 295 } else { 296 SetConsoleMode(handle, 297 dwMode & ~(ENABLE_ECHO_INPUT | ENABLE_LINE_INPUT)); 298 } 299 } 300 301 static char exec_dir[PATH_MAX]; 302 303 void qemu_init_exec_dir(const char *argv0) 304 { 305 306 char *p; 307 char buf[MAX_PATH]; 308 DWORD len; 309 310 len = GetModuleFileName(NULL, buf, sizeof(buf) - 1); 311 if (len == 0) { 312 return; 313 } 314 315 buf[len] = 0; 316 p = buf + len - 1; 317 while (p != buf && *p != '\\') { 318 p--; 319 } 320 *p = 0; 321 if (access(buf, R_OK) == 0) { 322 pstrcpy(exec_dir, sizeof(exec_dir), buf); 323 } 324 } 325 326 char *qemu_get_exec_dir(void) 327 { 328 return g_strdup(exec_dir); 329 } 330 331 /* 332 * The original implementation of g_poll from glib has a problem on Windows 333 * when using timeouts < 10 ms. 334 * 335 * Whenever g_poll is called with timeout < 10 ms, it does a quick poll instead 336 * of wait. This causes significant performance degradation of QEMU. 337 * 338 * The following code is a copy of the original code from glib/gpoll.c 339 * (glib commit 20f4d1820b8d4d0fc4447188e33efffd6d4a88d8 from 2014-02-19). 340 * Some debug code was removed and the code was reformatted. 341 * All other code modifications are marked with 'QEMU'. 342 */ 343 344 /* 345 * gpoll.c: poll(2) abstraction 346 * Copyright 1998 Owen Taylor 347 * Copyright 2008 Red Hat, Inc. 348 * 349 * This library is free software; you can redistribute it and/or 350 * modify it under the terms of the GNU Lesser General Public 351 * License as published by the Free Software Foundation; either 352 * version 2 of the License, or (at your option) any later version. 353 * 354 * This library is distributed in the hope that it will be useful, 355 * but WITHOUT ANY WARRANTY; without even the implied warranty of 356 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 357 * Lesser General Public License for more details. 358 * 359 * You should have received a copy of the GNU Lesser General Public 360 * License along with this library; if not, see <http://www.gnu.org/licenses/>. 361 */ 362 363 static int poll_rest(gboolean poll_msgs, HANDLE *handles, gint nhandles, 364 GPollFD *fds, guint nfds, gint timeout) 365 { 366 DWORD ready; 367 GPollFD *f; 368 int recursed_result; 369 370 if (poll_msgs) { 371 /* Wait for either messages or handles 372 * -> Use MsgWaitForMultipleObjectsEx 373 */ 374 ready = MsgWaitForMultipleObjectsEx(nhandles, handles, timeout, 375 QS_ALLINPUT, MWMO_ALERTABLE); 376 377 if (ready == WAIT_FAILED) { 378 gchar *emsg = g_win32_error_message(GetLastError()); 379 g_warning("MsgWaitForMultipleObjectsEx failed: %s", emsg); 380 g_free(emsg); 381 } 382 } else if (nhandles == 0) { 383 /* No handles to wait for, just the timeout */ 384 if (timeout == INFINITE) { 385 ready = WAIT_FAILED; 386 } else { 387 SleepEx(timeout, TRUE); 388 ready = WAIT_TIMEOUT; 389 } 390 } else { 391 /* Wait for just handles 392 * -> Use WaitForMultipleObjectsEx 393 */ 394 ready = 395 WaitForMultipleObjectsEx(nhandles, handles, FALSE, timeout, TRUE); 396 if (ready == WAIT_FAILED) { 397 gchar *emsg = g_win32_error_message(GetLastError()); 398 g_warning("WaitForMultipleObjectsEx failed: %s", emsg); 399 g_free(emsg); 400 } 401 } 402 403 if (ready == WAIT_FAILED) { 404 return -1; 405 } else if (ready == WAIT_TIMEOUT || ready == WAIT_IO_COMPLETION) { 406 return 0; 407 } else if (poll_msgs && ready == WAIT_OBJECT_0 + nhandles) { 408 for (f = fds; f < &fds[nfds]; ++f) { 409 if (f->fd == G_WIN32_MSG_HANDLE && f->events & G_IO_IN) { 410 f->revents |= G_IO_IN; 411 } 412 } 413 414 /* If we have a timeout, or no handles to poll, be satisfied 415 * with just noticing we have messages waiting. 416 */ 417 if (timeout != 0 || nhandles == 0) { 418 return 1; 419 } 420 421 /* If no timeout and handles to poll, recurse to poll them, 422 * too. 423 */ 424 recursed_result = poll_rest(FALSE, handles, nhandles, fds, nfds, 0); 425 return (recursed_result == -1) ? -1 : 1 + recursed_result; 426 } else if (/* QEMU: removed the following unneeded statement which causes 427 * a compiler warning: ready >= WAIT_OBJECT_0 && */ 428 ready < WAIT_OBJECT_0 + nhandles) { 429 for (f = fds; f < &fds[nfds]; ++f) { 430 if ((HANDLE) f->fd == handles[ready - WAIT_OBJECT_0]) { 431 f->revents = f->events; 432 } 433 } 434 435 /* If no timeout and polling several handles, recurse to poll 436 * the rest of them. 437 */ 438 if (timeout == 0 && nhandles > 1) { 439 /* Remove the handle that fired */ 440 int i; 441 if (ready < nhandles - 1) { 442 for (i = ready - WAIT_OBJECT_0 + 1; i < nhandles; i++) { 443 handles[i-1] = handles[i]; 444 } 445 } 446 nhandles--; 447 recursed_result = poll_rest(FALSE, handles, nhandles, fds, nfds, 0); 448 return (recursed_result == -1) ? -1 : 1 + recursed_result; 449 } 450 return 1; 451 } 452 453 return 0; 454 } 455 456 gint g_poll(GPollFD *fds, guint nfds, gint timeout) 457 { 458 HANDLE handles[MAXIMUM_WAIT_OBJECTS]; 459 gboolean poll_msgs = FALSE; 460 GPollFD *f; 461 gint nhandles = 0; 462 int retval; 463 464 for (f = fds; f < &fds[nfds]; ++f) { 465 if (f->fd == G_WIN32_MSG_HANDLE && (f->events & G_IO_IN)) { 466 poll_msgs = TRUE; 467 } else if (f->fd > 0) { 468 /* Don't add the same handle several times into the array, as 469 * docs say that is not allowed, even if it actually does seem 470 * to work. 471 */ 472 gint i; 473 474 for (i = 0; i < nhandles; i++) { 475 if (handles[i] == (HANDLE) f->fd) { 476 break; 477 } 478 } 479 480 if (i == nhandles) { 481 if (nhandles == MAXIMUM_WAIT_OBJECTS) { 482 g_warning("Too many handles to wait for!\n"); 483 break; 484 } else { 485 handles[nhandles++] = (HANDLE) f->fd; 486 } 487 } 488 } 489 } 490 491 for (f = fds; f < &fds[nfds]; ++f) { 492 f->revents = 0; 493 } 494 495 if (timeout == -1) { 496 timeout = INFINITE; 497 } 498 499 /* Polling for several things? */ 500 if (nhandles > 1 || (nhandles > 0 && poll_msgs)) { 501 /* First check if one or several of them are immediately 502 * available 503 */ 504 retval = poll_rest(poll_msgs, handles, nhandles, fds, nfds, 0); 505 506 /* If not, and we have a significant timeout, poll again with 507 * timeout then. Note that this will return indication for only 508 * one event, or only for messages. We ignore timeouts less than 509 * ten milliseconds as they are mostly pointless on Windows, the 510 * MsgWaitForMultipleObjectsEx() call will timeout right away 511 * anyway. 512 * 513 * Modification for QEMU: replaced timeout >= 10 by timeout > 0. 514 */ 515 if (retval == 0 && (timeout == INFINITE || timeout > 0)) { 516 retval = poll_rest(poll_msgs, handles, nhandles, 517 fds, nfds, timeout); 518 } 519 } else { 520 /* Just polling for one thing, so no need to check first if 521 * available immediately 522 */ 523 retval = poll_rest(poll_msgs, handles, nhandles, fds, nfds, timeout); 524 } 525 526 if (retval == -1) { 527 for (f = fds; f < &fds[nfds]; ++f) { 528 f->revents = 0; 529 } 530 } 531 532 return retval; 533 } 534 535 int getpagesize(void) 536 { 537 SYSTEM_INFO system_info; 538 539 GetSystemInfo(&system_info); 540 return system_info.dwPageSize; 541 } 542 543 void os_mem_prealloc(int fd, char *area, size_t memory) 544 { 545 int i; 546 size_t pagesize = getpagesize(); 547 548 memory = (memory + pagesize - 1) & -pagesize; 549 for (i = 0; i < memory / pagesize; i++) { 550 memset(area + pagesize * i, 0, 1); 551 } 552 } 553 554 555 /* XXX: put correct support for win32 */ 556 int qemu_read_password(char *buf, int buf_size) 557 { 558 int c, i; 559 560 printf("Password: "); 561 fflush(stdout); 562 i = 0; 563 for (;;) { 564 c = getchar(); 565 if (c < 0) { 566 buf[i] = '\0'; 567 return -1; 568 } else if (c == '\n') { 569 break; 570 } else if (i < (buf_size - 1)) { 571 buf[i++] = c; 572 } 573 } 574 buf[i] = '\0'; 575 return 0; 576 } 577 578 579 pid_t qemu_fork(Error **errp) 580 { 581 errno = ENOSYS; 582 error_setg_errno(errp, errno, 583 "cannot fork child process"); 584 return -1; 585 } 586 587 588 #undef connect 589 int qemu_connect_wrap(int sockfd, const struct sockaddr *addr, 590 socklen_t addrlen) 591 { 592 int ret; 593 ret = connect(sockfd, addr, addrlen); 594 if (ret < 0) { 595 errno = socket_error(); 596 } 597 return ret; 598 } 599 600 601 #undef listen 602 int qemu_listen_wrap(int sockfd, int backlog) 603 { 604 int ret; 605 ret = listen(sockfd, backlog); 606 if (ret < 0) { 607 errno = socket_error(); 608 } 609 return ret; 610 } 611 612 613 #undef bind 614 int qemu_bind_wrap(int sockfd, const struct sockaddr *addr, 615 socklen_t addrlen) 616 { 617 int ret; 618 ret = bind(sockfd, addr, addrlen); 619 if (ret < 0) { 620 errno = socket_error(); 621 } 622 return ret; 623 } 624 625 626 #undef socket 627 int qemu_socket_wrap(int domain, int type, int protocol) 628 { 629 int ret; 630 ret = socket(domain, type, protocol); 631 if (ret < 0) { 632 errno = socket_error(); 633 } 634 return ret; 635 } 636 637 638 #undef accept 639 int qemu_accept_wrap(int sockfd, struct sockaddr *addr, 640 socklen_t *addrlen) 641 { 642 int ret; 643 ret = accept(sockfd, addr, addrlen); 644 if (ret < 0) { 645 errno = socket_error(); 646 } 647 return ret; 648 } 649 650 651 #undef shutdown 652 int qemu_shutdown_wrap(int sockfd, int how) 653 { 654 int ret; 655 ret = shutdown(sockfd, how); 656 if (ret < 0) { 657 errno = socket_error(); 658 } 659 return ret; 660 } 661 662 663 #undef ioctlsocket 664 int qemu_ioctlsocket_wrap(int fd, int req, void *val) 665 { 666 int ret; 667 ret = ioctlsocket(fd, req, val); 668 if (ret < 0) { 669 errno = socket_error(); 670 } 671 return ret; 672 } 673 674 675 #undef closesocket 676 int qemu_closesocket_wrap(int fd) 677 { 678 int ret; 679 ret = closesocket(fd); 680 if (ret < 0) { 681 errno = socket_error(); 682 } 683 return ret; 684 } 685 686 687 #undef getsockopt 688 int qemu_getsockopt_wrap(int sockfd, int level, int optname, 689 void *optval, socklen_t *optlen) 690 { 691 int ret; 692 ret = getsockopt(sockfd, level, optname, optval, optlen); 693 if (ret < 0) { 694 errno = socket_error(); 695 } 696 return ret; 697 } 698 699 700 #undef setsockopt 701 int qemu_setsockopt_wrap(int sockfd, int level, int optname, 702 const void *optval, socklen_t optlen) 703 { 704 int ret; 705 ret = setsockopt(sockfd, level, optname, optval, optlen); 706 if (ret < 0) { 707 errno = socket_error(); 708 } 709 return ret; 710 } 711 712 713 #undef getpeername 714 int qemu_getpeername_wrap(int sockfd, struct sockaddr *addr, 715 socklen_t *addrlen) 716 { 717 int ret; 718 ret = getpeername(sockfd, addr, addrlen); 719 if (ret < 0) { 720 errno = socket_error(); 721 } 722 return ret; 723 } 724 725 726 #undef getsockname 727 int qemu_getsockname_wrap(int sockfd, struct sockaddr *addr, 728 socklen_t *addrlen) 729 { 730 int ret; 731 ret = getsockname(sockfd, addr, addrlen); 732 if (ret < 0) { 733 errno = socket_error(); 734 } 735 return ret; 736 } 737 738 739 #undef send 740 ssize_t qemu_send_wrap(int sockfd, const void *buf, size_t len, int flags) 741 { 742 int ret; 743 ret = send(sockfd, buf, len, flags); 744 if (ret < 0) { 745 errno = socket_error(); 746 } 747 return ret; 748 } 749 750 751 #undef sendto 752 ssize_t qemu_sendto_wrap(int sockfd, const void *buf, size_t len, int flags, 753 const struct sockaddr *addr, socklen_t addrlen) 754 { 755 int ret; 756 ret = sendto(sockfd, buf, len, flags, addr, addrlen); 757 if (ret < 0) { 758 errno = socket_error(); 759 } 760 return ret; 761 } 762 763 764 #undef recv 765 ssize_t qemu_recv_wrap(int sockfd, void *buf, size_t len, int flags) 766 { 767 int ret; 768 ret = recv(sockfd, buf, len, flags); 769 if (ret < 0) { 770 errno = socket_error(); 771 } 772 return ret; 773 } 774 775 776 #undef recvfrom 777 ssize_t qemu_recvfrom_wrap(int sockfd, void *buf, size_t len, int flags, 778 struct sockaddr *addr, socklen_t *addrlen) 779 { 780 int ret; 781 ret = recvfrom(sockfd, buf, len, flags, addr, addrlen); 782 if (ret < 0) { 783 errno = socket_error(); 784 } 785 return ret; 786 } 787