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 void os_close_file(int fd) 244 { 245 close(fd); 246 } 247 int os_fsync_file(int fd) 248 { 249 if (fsync(fd) < 0) 250 return -errno; 251 return 0; 252 } 253 254 int os_seek_file(int fd, unsigned long long offset) 255 { 256 unsigned long long actual; 257 258 actual = lseek64(fd, offset, SEEK_SET); 259 if (actual != offset) 260 return -errno; 261 return 0; 262 } 263 264 int os_read_file(int fd, void *buf, int len) 265 { 266 int n = read(fd, buf, len); 267 268 if (n < 0) 269 return -errno; 270 return n; 271 } 272 273 int os_pread_file(int fd, void *buf, int len, unsigned long long offset) 274 { 275 int n = pread(fd, buf, len, offset); 276 277 if (n < 0) 278 return -errno; 279 return n; 280 } 281 282 int os_write_file(int fd, const void *buf, int len) 283 { 284 int n = write(fd, (void *) buf, len); 285 286 if (n < 0) 287 return -errno; 288 return n; 289 } 290 291 int os_sync_file(int fd) 292 { 293 int n = fdatasync(fd); 294 295 if (n < 0) 296 return -errno; 297 return n; 298 } 299 300 int os_pwrite_file(int fd, const void *buf, int len, unsigned long long offset) 301 { 302 int n = pwrite(fd, (void *) buf, len, offset); 303 304 if (n < 0) 305 return -errno; 306 return n; 307 } 308 309 310 int os_file_size(const char *file, unsigned long long *size_out) 311 { 312 struct uml_stat buf; 313 int err; 314 315 err = os_stat_file(file, &buf); 316 if (err < 0) { 317 printk(UM_KERN_ERR "Couldn't stat \"%s\" : err = %d\n", file, 318 -err); 319 return err; 320 } 321 322 if (S_ISBLK(buf.ust_mode)) { 323 int fd; 324 long blocks; 325 326 fd = open(file, O_RDONLY, 0); 327 if (fd < 0) { 328 err = -errno; 329 printk(UM_KERN_ERR "Couldn't open \"%s\", " 330 "errno = %d\n", file, errno); 331 return err; 332 } 333 if (ioctl(fd, BLKGETSIZE, &blocks) < 0) { 334 err = -errno; 335 printk(UM_KERN_ERR "Couldn't get the block size of " 336 "\"%s\", errno = %d\n", file, errno); 337 close(fd); 338 return err; 339 } 340 *size_out = ((long long) blocks) * 512; 341 close(fd); 342 } 343 else *size_out = buf.ust_size; 344 345 return 0; 346 } 347 348 int os_file_modtime(const char *file, long long *modtime) 349 { 350 struct uml_stat buf; 351 int err; 352 353 err = os_stat_file(file, &buf); 354 if (err < 0) { 355 printk(UM_KERN_ERR "Couldn't stat \"%s\" : err = %d\n", file, 356 -err); 357 return err; 358 } 359 360 *modtime = buf.ust_mtime; 361 return 0; 362 } 363 364 int os_set_exec_close(int fd) 365 { 366 int err; 367 368 CATCH_EINTR(err = fcntl(fd, F_SETFD, FD_CLOEXEC)); 369 370 if (err < 0) 371 return -errno; 372 return err; 373 } 374 375 int os_pipe(int *fds, int stream, int close_on_exec) 376 { 377 int err, type = stream ? SOCK_STREAM : SOCK_DGRAM; 378 379 err = socketpair(AF_UNIX, type, 0, fds); 380 if (err < 0) 381 return -errno; 382 383 if (!close_on_exec) 384 return 0; 385 386 err = os_set_exec_close(fds[0]); 387 if (err < 0) 388 goto error; 389 390 err = os_set_exec_close(fds[1]); 391 if (err < 0) 392 goto error; 393 394 return 0; 395 396 error: 397 printk(UM_KERN_ERR "os_pipe : Setting FD_CLOEXEC failed, err = %d\n", 398 -err); 399 close(fds[1]); 400 close(fds[0]); 401 return err; 402 } 403 404 int os_set_fd_async(int fd) 405 { 406 int err, flags; 407 408 flags = fcntl(fd, F_GETFL); 409 if (flags < 0) 410 return -errno; 411 412 flags |= O_ASYNC | O_NONBLOCK; 413 if (fcntl(fd, F_SETFL, flags) < 0) { 414 err = -errno; 415 printk(UM_KERN_ERR "os_set_fd_async : failed to set O_ASYNC " 416 "and O_NONBLOCK on fd # %d, errno = %d\n", fd, errno); 417 return err; 418 } 419 420 if ((fcntl(fd, F_SETSIG, SIGIO) < 0) || 421 (fcntl(fd, F_SETOWN, os_getpid()) < 0)) { 422 err = -errno; 423 printk(UM_KERN_ERR "os_set_fd_async : Failed to fcntl F_SETOWN " 424 "(or F_SETSIG) fd %d, errno = %d\n", fd, errno); 425 return err; 426 } 427 428 return 0; 429 } 430 431 int os_clear_fd_async(int fd) 432 { 433 int flags; 434 435 flags = fcntl(fd, F_GETFL); 436 if (flags < 0) 437 return -errno; 438 439 flags &= ~(O_ASYNC | O_NONBLOCK); 440 if (fcntl(fd, F_SETFL, flags) < 0) 441 return -errno; 442 return 0; 443 } 444 445 int os_set_fd_block(int fd, int blocking) 446 { 447 int flags; 448 449 flags = fcntl(fd, F_GETFL); 450 if (flags < 0) 451 return -errno; 452 453 if (blocking) 454 flags &= ~O_NONBLOCK; 455 else 456 flags |= O_NONBLOCK; 457 458 if (fcntl(fd, F_SETFL, flags) < 0) 459 return -errno; 460 461 return 0; 462 } 463 464 int os_accept_connection(int fd) 465 { 466 int new; 467 468 new = accept(fd, NULL, 0); 469 if (new < 0) 470 return -errno; 471 return new; 472 } 473 474 #ifndef SHUT_RD 475 #define SHUT_RD 0 476 #endif 477 478 #ifndef SHUT_WR 479 #define SHUT_WR 1 480 #endif 481 482 #ifndef SHUT_RDWR 483 #define SHUT_RDWR 2 484 #endif 485 486 int os_shutdown_socket(int fd, int r, int w) 487 { 488 int what, err; 489 490 if (r && w) 491 what = SHUT_RDWR; 492 else if (r) 493 what = SHUT_RD; 494 else if (w) 495 what = SHUT_WR; 496 else 497 return -EINVAL; 498 499 err = shutdown(fd, what); 500 if (err < 0) 501 return -errno; 502 return 0; 503 } 504 505 int os_rcv_fd(int fd, int *helper_pid_out) 506 { 507 int new, n; 508 char buf[CMSG_SPACE(sizeof(new))]; 509 struct msghdr msg; 510 struct cmsghdr *cmsg; 511 struct iovec iov; 512 513 msg.msg_name = NULL; 514 msg.msg_namelen = 0; 515 iov = ((struct iovec) { .iov_base = helper_pid_out, 516 .iov_len = sizeof(*helper_pid_out) }); 517 msg.msg_iov = &iov; 518 msg.msg_iovlen = 1; 519 msg.msg_control = buf; 520 msg.msg_controllen = sizeof(buf); 521 msg.msg_flags = 0; 522 523 n = recvmsg(fd, &msg, 0); 524 if (n < 0) 525 return -errno; 526 else if (n != iov.iov_len) 527 *helper_pid_out = -1; 528 529 cmsg = CMSG_FIRSTHDR(&msg); 530 if (cmsg == NULL) { 531 printk(UM_KERN_ERR "rcv_fd didn't receive anything, " 532 "error = %d\n", errno); 533 return -1; 534 } 535 if ((cmsg->cmsg_level != SOL_SOCKET) || 536 (cmsg->cmsg_type != SCM_RIGHTS)) { 537 printk(UM_KERN_ERR "rcv_fd didn't receive a descriptor\n"); 538 return -1; 539 } 540 541 new = ((int *) CMSG_DATA(cmsg))[0]; 542 return new; 543 } 544 545 int os_create_unix_socket(const char *file, int len, int close_on_exec) 546 { 547 struct sockaddr_un addr; 548 int sock, err; 549 550 sock = socket(PF_UNIX, SOCK_DGRAM, 0); 551 if (sock < 0) 552 return -errno; 553 554 if (close_on_exec) { 555 err = os_set_exec_close(sock); 556 if (err < 0) 557 printk(UM_KERN_ERR "create_unix_socket : " 558 "close_on_exec failed, err = %d", -err); 559 } 560 561 addr.sun_family = AF_UNIX; 562 563 snprintf(addr.sun_path, len, "%s", file); 564 565 err = bind(sock, (struct sockaddr *) &addr, sizeof(addr)); 566 if (err < 0) 567 return -errno; 568 569 return sock; 570 } 571 572 void os_flush_stdout(void) 573 { 574 fflush(stdout); 575 } 576 577 int os_lock_file(int fd, int excl) 578 { 579 int type = excl ? F_WRLCK : F_RDLCK; 580 struct flock lock = ((struct flock) { .l_type = type, 581 .l_whence = SEEK_SET, 582 .l_start = 0, 583 .l_len = 0 } ); 584 int err, save; 585 586 err = fcntl(fd, F_SETLK, &lock); 587 if (!err) 588 goto out; 589 590 save = -errno; 591 err = fcntl(fd, F_GETLK, &lock); 592 if (err) { 593 err = -errno; 594 goto out; 595 } 596 597 printk(UM_KERN_ERR "F_SETLK failed, file already locked by pid %d\n", 598 lock.l_pid); 599 err = save; 600 out: 601 return err; 602 } 603 604 unsigned os_major(unsigned long long dev) 605 { 606 return major(dev); 607 } 608 609 unsigned os_minor(unsigned long long dev) 610 { 611 return minor(dev); 612 } 613 614 unsigned long long os_makedev(unsigned major, unsigned minor) 615 { 616 return makedev(major, minor); 617 } 618 619 int os_falloc_punch(int fd, unsigned long long offset, int len) 620 { 621 int n = fallocate(fd, FALLOC_FL_PUNCH_HOLE|FALLOC_FL_KEEP_SIZE, offset, len); 622 623 if (n < 0) 624 return -errno; 625 return n; 626 } 627 628 int os_eventfd(unsigned int initval, int flags) 629 { 630 int fd = eventfd(initval, flags); 631 632 if (fd < 0) 633 return -errno; 634 return fd; 635 } 636 637 int os_sendmsg_fds(int fd, const void *buf, unsigned int len, const int *fds, 638 unsigned int fds_num) 639 { 640 struct iovec iov = { 641 .iov_base = (void *) buf, 642 .iov_len = len, 643 }; 644 union { 645 char control[CMSG_SPACE(sizeof(*fds) * OS_SENDMSG_MAX_FDS)]; 646 struct cmsghdr align; 647 } u; 648 unsigned int fds_size = sizeof(*fds) * fds_num; 649 struct msghdr msg = { 650 .msg_iov = &iov, 651 .msg_iovlen = 1, 652 .msg_control = u.control, 653 .msg_controllen = CMSG_SPACE(fds_size), 654 }; 655 struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msg); 656 int err; 657 658 if (fds_num > OS_SENDMSG_MAX_FDS) 659 return -EINVAL; 660 memset(u.control, 0, sizeof(u.control)); 661 cmsg->cmsg_level = SOL_SOCKET; 662 cmsg->cmsg_type = SCM_RIGHTS; 663 cmsg->cmsg_len = CMSG_LEN(fds_size); 664 memcpy(CMSG_DATA(cmsg), fds, fds_size); 665 err = sendmsg(fd, &msg, 0); 666 667 if (err < 0) 668 return -errno; 669 return err; 670 } 671 672 int os_poll(unsigned int n, const int *fds) 673 { 674 /* currently need 2 FDs at most so avoid dynamic allocation */ 675 struct pollfd pollfds[2] = {}; 676 unsigned int i; 677 int ret; 678 679 if (n > ARRAY_SIZE(pollfds)) 680 return -EINVAL; 681 682 for (i = 0; i < n; i++) { 683 pollfds[i].fd = fds[i]; 684 pollfds[i].events = POLLIN; 685 } 686 687 ret = poll(pollfds, n, -1); 688 if (ret < 0) 689 return -errno; 690 691 /* Return the index of the available FD */ 692 for (i = 0; i < n; i++) { 693 if (pollfds[i].revents) 694 return i; 695 } 696 697 return -EIO; 698 } 699