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