1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) 4 */ 5 6 #include <stdio.h> 7 #include <unistd.h> 8 #include <stdlib.h> 9 #include <string.h> 10 #include <errno.h> 11 #include <fcntl.h> 12 #include <signal.h> 13 #include <linux/falloc.h> 14 #include <sys/ioctl.h> 15 #include <sys/mount.h> 16 #include <sys/socket.h> 17 #include <sys/stat.h> 18 #include <sys/sysmacros.h> 19 #include <sys/un.h> 20 #include <sys/types.h> 21 #include <sys/eventfd.h> 22 #include <poll.h> 23 #include <os.h> 24 25 static void copy_stat(struct uml_stat *dst, const struct stat64 *src) 26 { 27 *dst = ((struct uml_stat) { 28 .ust_dev = src->st_dev, /* device */ 29 .ust_ino = src->st_ino, /* inode */ 30 .ust_mode = src->st_mode, /* protection */ 31 .ust_nlink = src->st_nlink, /* number of hard links */ 32 .ust_uid = src->st_uid, /* user ID of owner */ 33 .ust_gid = src->st_gid, /* group ID of owner */ 34 .ust_size = src->st_size, /* total size, in bytes */ 35 .ust_blksize = src->st_blksize, /* blocksize for filesys I/O */ 36 .ust_blocks = src->st_blocks, /* number of blocks allocated */ 37 .ust_atime = src->st_atime, /* time of last access */ 38 .ust_mtime = src->st_mtime, /* time of last modification */ 39 .ust_ctime = src->st_ctime, /* time of last change */ 40 }); 41 } 42 43 int os_stat_fd(const int fd, struct uml_stat *ubuf) 44 { 45 struct stat64 sbuf; 46 int err; 47 48 CATCH_EINTR(err = fstat64(fd, &sbuf)); 49 if (err < 0) 50 return -errno; 51 52 if (ubuf != NULL) 53 copy_stat(ubuf, &sbuf); 54 return err; 55 } 56 57 int os_stat_file(const char *file_name, struct uml_stat *ubuf) 58 { 59 struct stat64 sbuf; 60 int err; 61 62 CATCH_EINTR(err = stat64(file_name, &sbuf)); 63 if (err < 0) 64 return -errno; 65 66 if (ubuf != NULL) 67 copy_stat(ubuf, &sbuf); 68 return err; 69 } 70 71 int os_access(const char *file, int mode) 72 { 73 int amode, err; 74 75 amode = (mode & OS_ACC_R_OK ? R_OK : 0) | 76 (mode & OS_ACC_W_OK ? W_OK : 0) | 77 (mode & OS_ACC_X_OK ? X_OK : 0) | 78 (mode & OS_ACC_F_OK ? F_OK : 0); 79 80 err = access(file, amode); 81 if (err < 0) 82 return -errno; 83 84 return 0; 85 } 86 87 /* FIXME? required only by hostaudio (because it passes ioctls verbatim) */ 88 int os_ioctl_generic(int fd, unsigned int cmd, unsigned long arg) 89 { 90 int err; 91 92 err = ioctl(fd, cmd, arg); 93 if (err < 0) 94 return -errno; 95 96 return err; 97 } 98 99 /* FIXME: ensure namebuf in os_get_if_name is big enough */ 100 int os_get_ifname(int fd, char* namebuf) 101 { 102 if (ioctl(fd, SIOCGIFNAME, namebuf) < 0) 103 return -errno; 104 105 return 0; 106 } 107 108 int os_set_slip(int fd) 109 { 110 int disc, sencap; 111 112 disc = N_SLIP; 113 if (ioctl(fd, TIOCSETD, &disc) < 0) 114 return -errno; 115 116 sencap = 0; 117 if (ioctl(fd, SIOCSIFENCAP, &sencap) < 0) 118 return -errno; 119 120 return 0; 121 } 122 123 int os_mode_fd(int fd, int mode) 124 { 125 int err; 126 127 CATCH_EINTR(err = fchmod(fd, mode)); 128 if (err < 0) 129 return -errno; 130 131 return 0; 132 } 133 134 int os_file_type(char *file) 135 { 136 struct uml_stat buf; 137 int err; 138 139 err = os_stat_file(file, &buf); 140 if (err < 0) 141 return err; 142 143 if (S_ISDIR(buf.ust_mode)) 144 return OS_TYPE_DIR; 145 else if (S_ISLNK(buf.ust_mode)) 146 return OS_TYPE_SYMLINK; 147 else if (S_ISCHR(buf.ust_mode)) 148 return OS_TYPE_CHARDEV; 149 else if (S_ISBLK(buf.ust_mode)) 150 return OS_TYPE_BLOCKDEV; 151 else if (S_ISFIFO(buf.ust_mode)) 152 return OS_TYPE_FIFO; 153 else if (S_ISSOCK(buf.ust_mode)) 154 return OS_TYPE_SOCK; 155 else return OS_TYPE_FILE; 156 } 157 158 int os_file_mode(const char *file, struct openflags *mode_out) 159 { 160 int err; 161 162 *mode_out = OPENFLAGS(); 163 164 err = access(file, W_OK); 165 if (err && (errno != EACCES)) 166 return -errno; 167 else if (!err) 168 *mode_out = of_write(*mode_out); 169 170 err = access(file, R_OK); 171 if (err && (errno != EACCES)) 172 return -errno; 173 else if (!err) 174 *mode_out = of_read(*mode_out); 175 176 return err; 177 } 178 179 int os_open_file(const char *file, struct openflags flags, int mode) 180 { 181 int fd, err, f = 0; 182 183 if (flags.r && flags.w) 184 f = O_RDWR; 185 else if (flags.r) 186 f = O_RDONLY; 187 else if (flags.w) 188 f = O_WRONLY; 189 else f = 0; 190 191 if (flags.s) 192 f |= O_SYNC; 193 if (flags.c) 194 f |= O_CREAT; 195 if (flags.t) 196 f |= O_TRUNC; 197 if (flags.e) 198 f |= O_EXCL; 199 if (flags.a) 200 f |= O_APPEND; 201 202 fd = open64(file, f, mode); 203 if (fd < 0) 204 return -errno; 205 206 if (flags.cl && fcntl(fd, F_SETFD, 1)) { 207 err = -errno; 208 close(fd); 209 return err; 210 } 211 212 return fd; 213 } 214 215 int os_connect_socket(const char *name) 216 { 217 struct sockaddr_un sock; 218 int fd, err; 219 220 sock.sun_family = AF_UNIX; 221 snprintf(sock.sun_path, sizeof(sock.sun_path), "%s", name); 222 223 fd = socket(AF_UNIX, SOCK_STREAM, 0); 224 if (fd < 0) { 225 err = -errno; 226 goto out; 227 } 228 229 err = connect(fd, (struct sockaddr *) &sock, sizeof(sock)); 230 if (err) { 231 err = -errno; 232 goto out_close; 233 } 234 235 return fd; 236 237 out_close: 238 close(fd); 239 out: 240 return err; 241 } 242 243 int os_dup_file(int fd) 244 { 245 int new_fd = dup(fd); 246 247 if (new_fd < 0) 248 return -errno; 249 250 return new_fd; 251 } 252 253 void os_close_file(int fd) 254 { 255 close(fd); 256 } 257 int os_fsync_file(int fd) 258 { 259 if (fsync(fd) < 0) 260 return -errno; 261 return 0; 262 } 263 264 int os_seek_file(int fd, unsigned long long offset) 265 { 266 unsigned long long actual; 267 268 actual = lseek64(fd, offset, SEEK_SET); 269 if (actual != offset) 270 return -errno; 271 return 0; 272 } 273 274 int os_read_file(int fd, void *buf, int len) 275 { 276 int n = read(fd, buf, len); 277 278 if (n < 0) 279 return -errno; 280 return n; 281 } 282 283 int os_pread_file(int fd, void *buf, int len, unsigned long long offset) 284 { 285 int n = pread(fd, buf, len, offset); 286 287 if (n < 0) 288 return -errno; 289 return n; 290 } 291 292 int os_write_file(int fd, const void *buf, int len) 293 { 294 int n = write(fd, (void *) buf, len); 295 296 if (n < 0) 297 return -errno; 298 return n; 299 } 300 301 int os_sync_file(int fd) 302 { 303 int n = fdatasync(fd); 304 305 if (n < 0) 306 return -errno; 307 return n; 308 } 309 310 int os_pwrite_file(int fd, const void *buf, int len, unsigned long long offset) 311 { 312 int n = pwrite(fd, (void *) buf, len, offset); 313 314 if (n < 0) 315 return -errno; 316 return n; 317 } 318 319 320 int os_file_size(const char *file, unsigned long long *size_out) 321 { 322 struct uml_stat buf; 323 int err; 324 325 err = os_stat_file(file, &buf); 326 if (err < 0) { 327 printk(UM_KERN_ERR "Couldn't stat \"%s\" : err = %d\n", file, 328 -err); 329 return err; 330 } 331 332 if (S_ISBLK(buf.ust_mode)) { 333 int fd; 334 long blocks; 335 336 fd = open(file, O_RDONLY, 0); 337 if (fd < 0) { 338 err = -errno; 339 printk(UM_KERN_ERR "Couldn't open \"%s\", " 340 "errno = %d\n", file, errno); 341 return err; 342 } 343 if (ioctl(fd, BLKGETSIZE, &blocks) < 0) { 344 err = -errno; 345 printk(UM_KERN_ERR "Couldn't get the block size of " 346 "\"%s\", errno = %d\n", file, errno); 347 close(fd); 348 return err; 349 } 350 *size_out = ((long long) blocks) * 512; 351 close(fd); 352 } 353 else *size_out = buf.ust_size; 354 355 return 0; 356 } 357 358 int os_file_modtime(const char *file, long long *modtime) 359 { 360 struct uml_stat buf; 361 int err; 362 363 err = os_stat_file(file, &buf); 364 if (err < 0) { 365 printk(UM_KERN_ERR "Couldn't stat \"%s\" : err = %d\n", file, 366 -err); 367 return err; 368 } 369 370 *modtime = buf.ust_mtime; 371 return 0; 372 } 373 374 int os_set_exec_close(int fd) 375 { 376 int err; 377 378 CATCH_EINTR(err = fcntl(fd, F_SETFD, FD_CLOEXEC)); 379 380 if (err < 0) 381 return -errno; 382 return err; 383 } 384 385 int os_pipe(int *fds, int stream, int close_on_exec) 386 { 387 int err, type = stream ? SOCK_STREAM : SOCK_DGRAM; 388 389 err = socketpair(AF_UNIX, type, 0, fds); 390 if (err < 0) 391 return -errno; 392 393 if (!close_on_exec) 394 return 0; 395 396 err = os_set_exec_close(fds[0]); 397 if (err < 0) 398 goto error; 399 400 err = os_set_exec_close(fds[1]); 401 if (err < 0) 402 goto error; 403 404 return 0; 405 406 error: 407 printk(UM_KERN_ERR "os_pipe : Setting FD_CLOEXEC failed, err = %d\n", 408 -err); 409 close(fds[1]); 410 close(fds[0]); 411 return err; 412 } 413 414 int os_set_fd_async(int fd) 415 { 416 int err, flags; 417 418 flags = fcntl(fd, F_GETFL); 419 if (flags < 0) 420 return -errno; 421 422 flags |= O_ASYNC | O_NONBLOCK; 423 if (fcntl(fd, F_SETFL, flags) < 0) { 424 err = -errno; 425 printk(UM_KERN_ERR "os_set_fd_async : failed to set O_ASYNC " 426 "and O_NONBLOCK on fd # %d, errno = %d\n", fd, errno); 427 return err; 428 } 429 430 if ((fcntl(fd, F_SETSIG, SIGIO) < 0) || 431 (fcntl(fd, F_SETOWN, os_getpid()) < 0)) { 432 err = -errno; 433 printk(UM_KERN_ERR "os_set_fd_async : Failed to fcntl F_SETOWN " 434 "(or F_SETSIG) fd %d, errno = %d\n", fd, errno); 435 return err; 436 } 437 438 return 0; 439 } 440 441 int os_clear_fd_async(int fd) 442 { 443 int flags; 444 445 flags = fcntl(fd, F_GETFL); 446 if (flags < 0) 447 return -errno; 448 449 flags &= ~(O_ASYNC | O_NONBLOCK); 450 if (fcntl(fd, F_SETFL, flags) < 0) 451 return -errno; 452 return 0; 453 } 454 455 int os_set_fd_block(int fd, int blocking) 456 { 457 int flags; 458 459 flags = fcntl(fd, F_GETFL); 460 if (flags < 0) 461 return -errno; 462 463 if (blocking) 464 flags &= ~O_NONBLOCK; 465 else 466 flags |= O_NONBLOCK; 467 468 if (fcntl(fd, F_SETFL, flags) < 0) 469 return -errno; 470 471 return 0; 472 } 473 474 int os_accept_connection(int fd) 475 { 476 int new; 477 478 new = accept(fd, NULL, 0); 479 if (new < 0) 480 return -errno; 481 return new; 482 } 483 484 #ifndef SHUT_RD 485 #define SHUT_RD 0 486 #endif 487 488 #ifndef SHUT_WR 489 #define SHUT_WR 1 490 #endif 491 492 #ifndef SHUT_RDWR 493 #define SHUT_RDWR 2 494 #endif 495 496 int os_shutdown_socket(int fd, int r, int w) 497 { 498 int what, err; 499 500 if (r && w) 501 what = SHUT_RDWR; 502 else if (r) 503 what = SHUT_RD; 504 else if (w) 505 what = SHUT_WR; 506 else 507 return -EINVAL; 508 509 err = shutdown(fd, what); 510 if (err < 0) 511 return -errno; 512 return 0; 513 } 514 515 int os_rcv_fd(int fd, int *helper_pid_out) 516 { 517 int new, n; 518 char buf[CMSG_SPACE(sizeof(new))]; 519 struct msghdr msg; 520 struct cmsghdr *cmsg; 521 struct iovec iov; 522 523 msg.msg_name = NULL; 524 msg.msg_namelen = 0; 525 iov = ((struct iovec) { .iov_base = helper_pid_out, 526 .iov_len = sizeof(*helper_pid_out) }); 527 msg.msg_iov = &iov; 528 msg.msg_iovlen = 1; 529 msg.msg_control = buf; 530 msg.msg_controllen = sizeof(buf); 531 msg.msg_flags = 0; 532 533 n = recvmsg(fd, &msg, 0); 534 if (n < 0) 535 return -errno; 536 else if (n != iov.iov_len) 537 *helper_pid_out = -1; 538 539 cmsg = CMSG_FIRSTHDR(&msg); 540 if (cmsg == NULL) { 541 printk(UM_KERN_ERR "rcv_fd didn't receive anything, " 542 "error = %d\n", errno); 543 return -1; 544 } 545 if ((cmsg->cmsg_level != SOL_SOCKET) || 546 (cmsg->cmsg_type != SCM_RIGHTS)) { 547 printk(UM_KERN_ERR "rcv_fd didn't receive a descriptor\n"); 548 return -1; 549 } 550 551 new = ((int *) CMSG_DATA(cmsg))[0]; 552 return new; 553 } 554 555 int os_create_unix_socket(const char *file, int len, int close_on_exec) 556 { 557 struct sockaddr_un addr; 558 int sock, err; 559 560 sock = socket(PF_UNIX, SOCK_DGRAM, 0); 561 if (sock < 0) 562 return -errno; 563 564 if (close_on_exec) { 565 err = os_set_exec_close(sock); 566 if (err < 0) 567 printk(UM_KERN_ERR "create_unix_socket : " 568 "close_on_exec failed, err = %d", -err); 569 } 570 571 addr.sun_family = AF_UNIX; 572 573 snprintf(addr.sun_path, len, "%s", file); 574 575 err = bind(sock, (struct sockaddr *) &addr, sizeof(addr)); 576 if (err < 0) 577 return -errno; 578 579 return sock; 580 } 581 582 void os_flush_stdout(void) 583 { 584 fflush(stdout); 585 } 586 587 int os_lock_file(int fd, int excl) 588 { 589 int type = excl ? F_WRLCK : F_RDLCK; 590 struct flock lock = ((struct flock) { .l_type = type, 591 .l_whence = SEEK_SET, 592 .l_start = 0, 593 .l_len = 0 } ); 594 int err, save; 595 596 err = fcntl(fd, F_SETLK, &lock); 597 if (!err) 598 goto out; 599 600 save = -errno; 601 err = fcntl(fd, F_GETLK, &lock); 602 if (err) { 603 err = -errno; 604 goto out; 605 } 606 607 printk(UM_KERN_ERR "F_SETLK failed, file already locked by pid %d\n", 608 lock.l_pid); 609 err = save; 610 out: 611 return err; 612 } 613 614 unsigned os_major(unsigned long long dev) 615 { 616 return major(dev); 617 } 618 619 unsigned os_minor(unsigned long long dev) 620 { 621 return minor(dev); 622 } 623 624 unsigned long long os_makedev(unsigned major, unsigned minor) 625 { 626 return makedev(major, minor); 627 } 628 629 int os_falloc_punch(int fd, unsigned long long offset, int len) 630 { 631 int n = fallocate(fd, FALLOC_FL_PUNCH_HOLE|FALLOC_FL_KEEP_SIZE, offset, len); 632 633 if (n < 0) 634 return -errno; 635 return n; 636 } 637 638 int os_falloc_zeroes(int fd, unsigned long long offset, int len) 639 { 640 int n = fallocate(fd, FALLOC_FL_ZERO_RANGE|FALLOC_FL_KEEP_SIZE, offset, len); 641 642 if (n < 0) 643 return -errno; 644 return n; 645 } 646 647 int os_eventfd(unsigned int initval, int flags) 648 { 649 int fd = eventfd(initval, flags); 650 651 if (fd < 0) 652 return -errno; 653 return fd; 654 } 655 656 int os_sendmsg_fds(int fd, const void *buf, unsigned int len, const int *fds, 657 unsigned int fds_num) 658 { 659 struct iovec iov = { 660 .iov_base = (void *) buf, 661 .iov_len = len, 662 }; 663 union { 664 char control[CMSG_SPACE(sizeof(*fds) * OS_SENDMSG_MAX_FDS)]; 665 struct cmsghdr align; 666 } u; 667 unsigned int fds_size = sizeof(*fds) * fds_num; 668 struct msghdr msg = { 669 .msg_iov = &iov, 670 .msg_iovlen = 1, 671 .msg_control = u.control, 672 .msg_controllen = CMSG_SPACE(fds_size), 673 }; 674 struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msg); 675 int err; 676 677 if (fds_num > OS_SENDMSG_MAX_FDS) 678 return -EINVAL; 679 memset(u.control, 0, sizeof(u.control)); 680 cmsg->cmsg_level = SOL_SOCKET; 681 cmsg->cmsg_type = SCM_RIGHTS; 682 cmsg->cmsg_len = CMSG_LEN(fds_size); 683 memcpy(CMSG_DATA(cmsg), fds, fds_size); 684 err = sendmsg(fd, &msg, 0); 685 686 if (err < 0) 687 return -errno; 688 return err; 689 } 690 691 int os_poll(unsigned int n, const int *fds) 692 { 693 /* currently need 2 FDs at most so avoid dynamic allocation */ 694 struct pollfd pollfds[2] = {}; 695 unsigned int i; 696 int ret; 697 698 if (n > ARRAY_SIZE(pollfds)) 699 return -EINVAL; 700 701 for (i = 0; i < n; i++) { 702 pollfds[i].fd = fds[i]; 703 pollfds[i].events = POLLIN; 704 } 705 706 ret = poll(pollfds, n, -1); 707 if (ret < 0) 708 return -errno; 709 710 /* Return the index of the available FD */ 711 for (i = 0; i < n; i++) { 712 if (pollfds[i].revents) 713 return i; 714 } 715 716 return -EIO; 717 } 718