arch/um/os-Linux/file.c

   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/mman.h>
  21 #include <sys/types.h>
  22 #include <sys/eventfd.h>
  23 #include <poll.h>
  24 #include <os.h>
  25
  26 static void copy_stat(struct uml_stat *dst, const struct stat64 *src)
  27 {
  28         *dst = ((struct uml_stat) {
  29                 .ust_dev     = src->st_dev,     /* device */
  30                 .ust_ino     = src->st_ino,     /* inode */
  31                 .ust_mode    = src->st_mode,    /* protection */
  32                 .ust_nlink   = src->st_nlink,   /* number of hard links */
  33                 .ust_uid     = src->st_uid,     /* user ID of owner */
  34                 .ust_gid     = src->st_gid,     /* group ID of owner */
  35                 .ust_size    = src->st_size,    /* total size, in bytes */
  36                 .ust_blksize = src->st_blksize, /* blocksize for filesys I/O */
  37                 .ust_blocks  = src->st_blocks,  /* number of blocks allocated */
  38                 .ust_atime   = src->st_atime,   /* time of last access */
  39                 .ust_mtime   = src->st_mtime,   /* time of last modification */
  40                 .ust_ctime   = src->st_ctime,   /* time of last change */
  41         });
  42 }
  43
  44 int os_stat_fd(const int fd, struct uml_stat *ubuf)
  45 {
  46         struct stat64 sbuf;
  47         int err;
  48
  49         CATCH_EINTR(err = fstat64(fd, &sbuf));
  50         if (err < 0)
  51                 return -errno;
  52
  53         if (ubuf != NULL)
  54                 copy_stat(ubuf, &sbuf);
  55         return err;
  56 }
  57
  58 int os_stat_file(const char *file_name, struct uml_stat *ubuf)
  59 {
  60         struct stat64 sbuf;
  61         int err;
  62
  63         CATCH_EINTR(err = stat64(file_name, &sbuf));
  64         if (err < 0)
  65                 return -errno;
  66
  67         if (ubuf != NULL)
  68                 copy_stat(ubuf, &sbuf);
  69         return err;
  70 }
  71
  72 int os_access(const char *file, int mode)
  73 {
  74         int amode, err;
  75
  76         amode = (mode & OS_ACC_R_OK ? R_OK : 0) |
  77                 (mode & OS_ACC_W_OK ? W_OK : 0) |
  78                 (mode & OS_ACC_X_OK ? X_OK : 0) |
  79                 (mode & OS_ACC_F_OK ? F_OK : 0);
  80
  81         err = access(file, amode);
  82         if (err < 0)
  83                 return -errno;
  84
  85         return 0;
  86 }
  87
  88 /* FIXME? required only by hostaudio (because it passes ioctls verbatim) */
  89 int os_ioctl_generic(int fd, unsigned int cmd, unsigned long arg)
  90 {
  91         int err;
  92
  93         err = ioctl(fd, cmd, arg);
  94         if (err < 0)
  95                 return -errno;
  96
  97         return err;
  98 }
  99
 100 /* FIXME: ensure namebuf in os_get_if_name is big enough */
 101 int os_get_ifname(int fd, char* namebuf)
 102 {
 103         if (ioctl(fd, SIOCGIFNAME, namebuf) < 0)
 104                 return -errno;
 105
 106         return 0;
 107 }
 108
 109 int os_set_slip(int fd)
 110 {
 111         int disc, sencap;
 112
 113         disc = N_SLIP;
 114         if (ioctl(fd, TIOCSETD, &disc) < 0)
 115                 return -errno;
 116
 117         sencap = 0;
 118         if (ioctl(fd, SIOCSIFENCAP, &sencap) < 0)
 119                 return -errno;
 120
 121         return 0;
 122 }
 123
 124 int os_mode_fd(int fd, int mode)
 125 {
 126         int err;
 127
 128         CATCH_EINTR(err = fchmod(fd, mode));
 129         if (err < 0)
 130                 return -errno;
 131
 132         return 0;
 133 }
 134
 135 int os_file_type(char *file)
 136 {
 137         struct uml_stat buf;
 138         int err;
 139
 140         err = os_stat_file(file, &buf);
 141         if (err < 0)
 142                 return err;
 143
 144         if (S_ISDIR(buf.ust_mode))
 145                 return OS_TYPE_DIR;
 146         else if (S_ISLNK(buf.ust_mode))
 147                 return OS_TYPE_SYMLINK;
 148         else if (S_ISCHR(buf.ust_mode))
 149                 return OS_TYPE_CHARDEV;
 150         else if (S_ISBLK(buf.ust_mode))
 151                 return OS_TYPE_BLOCKDEV;
 152         else if (S_ISFIFO(buf.ust_mode))
 153                 return OS_TYPE_FIFO;
 154         else if (S_ISSOCK(buf.ust_mode))
 155                 return OS_TYPE_SOCK;
 156         else return OS_TYPE_FILE;
 157 }
 158
 159 int os_file_mode(const char *file, struct openflags *mode_out)
 160 {
 161         int err;
 162
 163         *mode_out = OPENFLAGS();
 164
 165         err = access(file, W_OK);
 166         if (err && (errno != EACCES))
 167                 return -errno;
 168         else if (!err)
 169                 *mode_out = of_write(*mode_out);
 170
 171         err = access(file, R_OK);
 172         if (err && (errno != EACCES))
 173                 return -errno;
 174         else if (!err)
 175                 *mode_out = of_read(*mode_out);
 176
 177         return err;
 178 }
 179
 180 int os_open_file(const char *file, struct openflags flags, int mode)
 181 {
 182         int fd, err, f = 0;
 183
 184         if (flags.r && flags.w)
 185                 f = O_RDWR;
 186         else if (flags.r)
 187                 f = O_RDONLY;
 188         else if (flags.w)
 189                 f = O_WRONLY;
 190         else f = 0;
 191
 192         if (flags.s)
 193                 f |= O_SYNC;
 194         if (flags.c)
 195                 f |= O_CREAT;
 196         if (flags.t)
 197                 f |= O_TRUNC;
 198         if (flags.e)
 199                 f |= O_EXCL;
 200         if (flags.a)
 201                 f |= O_APPEND;
 202
 203         fd = open64(file, f, mode);
 204         if (fd < 0)
 205                 return -errno;
 206
 207         if (flags.cl && fcntl(fd, F_SETFD, 1)) {
 208                 err = -errno;
 209                 close(fd);
 210                 return err;
 211         }
 212
 213         return fd;
 214 }
 215
 216 int os_connect_socket(const char *name)
 217 {
 218         struct sockaddr_un sock;
 219         int fd, err;
 220
 221         sock.sun_family = AF_UNIX;
 222         snprintf(sock.sun_path, sizeof(sock.sun_path), "%s", name);
 223
 224         fd = socket(AF_UNIX, SOCK_STREAM, 0);
 225         if (fd < 0) {
 226                 err = -errno;
 227                 goto out;
 228         }
 229
 230         err = connect(fd, (struct sockaddr *) &sock, sizeof(sock));
 231         if (err) {
 232                 err = -errno;
 233                 goto out_close;
 234         }
 235
 236         return fd;
 237
 238 out_close:
 239         close(fd);
 240 out:
 241         return err;
 242 }
 243
 244 int os_dup_file(int fd)
 245 {
 246         int new_fd = dup(fd);
 247
 248         if (new_fd < 0)
 249                 return -errno;
 250
 251         return new_fd;
 252 }
 253
 254 void os_close_file(int fd)
 255 {
 256         close(fd);
 257 }
 258 int os_fsync_file(int fd)
 259 {
 260         if (fsync(fd) < 0)
 261             return -errno;
 262         return 0;
 263 }
 264
 265 int os_seek_file(int fd, unsigned long long offset)
 266 {
 267         unsigned long long actual;
 268
 269         actual = lseek64(fd, offset, SEEK_SET);
 270         if (actual != offset)
 271                 return -errno;
 272         return 0;
 273 }
 274
 275 int os_read_file(int fd, void *buf, int len)
 276 {
 277         int n = read(fd, buf, len);
 278
 279         if (n < 0)
 280                 return -errno;
 281         return n;
 282 }
 283
 284 int os_pread_file(int fd, void *buf, int len, unsigned long long offset)
 285 {
 286         int n = pread(fd, buf, len, offset);
 287
 288         if (n < 0)
 289                 return -errno;
 290         return n;
 291 }
 292
 293 int os_write_file(int fd, const void *buf, int len)
 294 {
 295         int n = write(fd, (void *) buf, len);
 296
 297         if (n < 0)
 298                 return -errno;
 299         return n;
 300 }
 301
 302 int os_sync_file(int fd)
 303 {
 304         int n = fdatasync(fd);
 305
 306         if (n < 0)
 307                 return -errno;
 308         return n;
 309 }
 310
 311 int os_pwrite_file(int fd, const void *buf, int len, unsigned long long offset)
 312 {
 313         int n = pwrite(fd, (void *) buf, len, offset);
 314
 315         if (n < 0)
 316                 return -errno;
 317         return n;
 318 }
 319
 320
 321 int os_file_size(const char *file, unsigned long long *size_out)
 322 {
 323         struct uml_stat buf;
 324         int err;
 325
 326         err = os_stat_file(file, &buf);
 327         if (err < 0) {
 328                 printk(UM_KERN_ERR "Couldn't stat \"%s\" : err = %d\n", file,
 329                        -err);
 330                 return err;
 331         }
 332
 333         if (S_ISBLK(buf.ust_mode)) {
 334                 int fd;
 335                 long blocks;
 336
 337                 fd = open(file, O_RDONLY, 0);
 338                 if (fd < 0) {
 339                         err = -errno;
 340                         printk(UM_KERN_ERR "Couldn't open \"%s\", "
 341                                "errno = %d\n", file, errno);
 342                         return err;
 343                 }
 344                 if (ioctl(fd, BLKGETSIZE, &blocks) < 0) {
 345                         err = -errno;
 346                         printk(UM_KERN_ERR "Couldn't get the block size of "
 347                                "\"%s\", errno = %d\n", file, errno);
 348                         close(fd);
 349                         return err;
 350                 }
 351                 *size_out = ((long long) blocks) * 512;
 352                 close(fd);
 353         }
 354         else *size_out = buf.ust_size;
 355
 356         return 0;
 357 }
 358
 359 int os_file_modtime(const char *file, long long *modtime)
 360 {
 361         struct uml_stat buf;
 362         int err;
 363
 364         err = os_stat_file(file, &buf);
 365         if (err < 0) {
 366                 printk(UM_KERN_ERR "Couldn't stat \"%s\" : err = %d\n", file,
 367                        -err);
 368                 return err;
 369         }
 370
 371         *modtime = buf.ust_mtime;
 372         return 0;
 373 }
 374
 375 int os_set_exec_close(int fd)
 376 {
 377         int err;
 378
 379         CATCH_EINTR(err = fcntl(fd, F_SETFD, FD_CLOEXEC));
 380
 381         if (err < 0)
 382                 return -errno;
 383         return err;
 384 }
 385
 386 int os_pipe(int *fds, int stream, int close_on_exec)
 387 {
 388         int err, type = stream ? SOCK_STREAM : SOCK_DGRAM;
 389
 390         err = socketpair(AF_UNIX, type, 0, fds);
 391         if (err < 0)
 392                 return -errno;
 393
 394         if (!close_on_exec)
 395                 return 0;
 396
 397         err = os_set_exec_close(fds[0]);
 398         if (err < 0)
 399                 goto error;
 400
 401         err = os_set_exec_close(fds[1]);
 402         if (err < 0)
 403                 goto error;
 404
 405         return 0;
 406
 407  error:
 408         printk(UM_KERN_ERR "os_pipe : Setting FD_CLOEXEC failed, err = %d\n",
 409                -err);
 410         close(fds[1]);
 411         close(fds[0]);
 412         return err;
 413 }
 414
 415 int os_set_fd_async(int fd)
 416 {
 417         int err, flags;
 418
 419         flags = fcntl(fd, F_GETFL);
 420         if (flags < 0)
 421                 return -errno;
 422
 423         flags |= O_ASYNC | O_NONBLOCK;
 424         if (fcntl(fd, F_SETFL, flags) < 0) {
 425                 err = -errno;
 426                 printk(UM_KERN_ERR "os_set_fd_async : failed to set O_ASYNC "
 427                        "and O_NONBLOCK on fd # %d, errno = %d\n", fd, errno);
 428                 return err;
 429         }
 430
 431         if ((fcntl(fd, F_SETSIG, SIGIO) < 0) ||
 432             (fcntl(fd, F_SETOWN, os_getpid()) < 0)) {
 433                 err = -errno;
 434                 printk(UM_KERN_ERR "os_set_fd_async : Failed to fcntl F_SETOWN "
 435                        "(or F_SETSIG) fd %d, errno = %d\n", fd, errno);
 436                 return err;
 437         }
 438
 439         return 0;
 440 }
 441
 442 int os_clear_fd_async(int fd)
 443 {
 444         int flags;
 445
 446         flags = fcntl(fd, F_GETFL);
 447         if (flags < 0)
 448                 return -errno;
 449
 450         flags &= ~(O_ASYNC | O_NONBLOCK);
 451         if (fcntl(fd, F_SETFL, flags) < 0)
 452                 return -errno;
 453         return 0;
 454 }
 455
 456 int os_set_fd_block(int fd, int blocking)
 457 {
 458         int flags;
 459
 460         flags = fcntl(fd, F_GETFL);
 461         if (flags < 0)
 462                 return -errno;
 463
 464         if (blocking)
 465                 flags &= ~O_NONBLOCK;
 466         else
 467                 flags |= O_NONBLOCK;
 468
 469         if (fcntl(fd, F_SETFL, flags) < 0)
 470                 return -errno;
 471
 472         return 0;
 473 }
 474
 475 int os_accept_connection(int fd)
 476 {
 477         int new;
 478
 479         new = accept(fd, NULL, 0);
 480         if (new < 0)
 481                 return -errno;
 482         return new;
 483 }
 484
 485 #ifndef SHUT_RD
 486 #define SHUT_RD 0
 487 #endif
 488
 489 #ifndef SHUT_WR
 490 #define SHUT_WR 1
 491 #endif
 492
 493 #ifndef SHUT_RDWR
 494 #define SHUT_RDWR 2
 495 #endif
 496
 497 int os_shutdown_socket(int fd, int r, int w)
 498 {
 499         int what, err;
 500
 501         if (r && w)
 502                 what = SHUT_RDWR;
 503         else if (r)
 504                 what = SHUT_RD;
 505         else if (w)
 506                 what = SHUT_WR;
 507         else
 508                 return -EINVAL;
 509
 510         err = shutdown(fd, what);
 511         if (err < 0)
 512                 return -errno;
 513         return 0;
 514 }
 515
 516 /**
 517  * os_rcv_fd_msg - receive message with (optional) FDs
 518  * @fd: the FD to receive from
 519  * @fds: the array for FDs to write to
 520  * @n_fds: number of FDs to receive (@fds array size)
 521  * @data: the message buffer
 522  * @data_len: the size of the message to receive
 523  *
 524  * Receive a message with FDs.
 525  *
 526  * Returns: the size of the received message, or an error code
 527  */
 528 ssize_t os_rcv_fd_msg(int fd, int *fds, unsigned int n_fds,
 529                       void *data, size_t data_len)
 530 {
 531 #define MAX_RCV_FDS     2
 532         char buf[CMSG_SPACE(sizeof(*fds) * MAX_RCV_FDS)];
 533         struct cmsghdr *cmsg;
 534         struct iovec iov = {
 535                 .iov_base = data,
 536                 .iov_len = data_len,
 537         };
 538         struct msghdr msg = {
 539                 .msg_iov = &iov,
 540                 .msg_iovlen = 1,
 541                 .msg_control = buf,
 542                 .msg_controllen = CMSG_SPACE(sizeof(*fds) * n_fds),
 543         };
 544         int n;
 545
 546         if (n_fds > MAX_RCV_FDS)
 547                 return -EINVAL;
 548
 549         n = recvmsg(fd, &msg, 0);
 550         if (n < 0)
 551                 return -errno;
 552
 553         cmsg = CMSG_FIRSTHDR(&msg);
 554         if (!cmsg ||
 555             cmsg->cmsg_level != SOL_SOCKET ||
 556             cmsg->cmsg_type != SCM_RIGHTS)
 557                 return n;
 558
 559         memcpy(fds, CMSG_DATA(cmsg), cmsg->cmsg_len);
 560         return n;
 561 }
 562
 563 int os_create_unix_socket(const char *file, int len, int close_on_exec)
 564 {
 565         struct sockaddr_un addr;
 566         int sock, err;
 567
 568         sock = socket(PF_UNIX, SOCK_DGRAM, 0);
 569         if (sock < 0)
 570                 return -errno;
 571
 572         if (close_on_exec) {
 573                 err = os_set_exec_close(sock);
 574                 if (err < 0)
 575                         printk(UM_KERN_ERR "create_unix_socket : "
 576                                "close_on_exec failed, err = %d", -err);
 577         }
 578
 579         addr.sun_family = AF_UNIX;
 580
 581         snprintf(addr.sun_path, len, "%s", file);
 582
 583         err = bind(sock, (struct sockaddr *) &addr, sizeof(addr));
 584         if (err < 0)
 585                 return -errno;
 586
 587         return sock;
 588 }
 589
 590 void os_flush_stdout(void)
 591 {
 592         fflush(stdout);
 593 }
 594
 595 int os_lock_file(int fd, int excl)
 596 {
 597         int type = excl ? F_WRLCK : F_RDLCK;
 598         struct flock lock = ((struct flock) { .l_type   = type,
 599                                               .l_whence = SEEK_SET,
 600                                               .l_start  = 0,
 601                                               .l_len    = 0 } );
 602         int err, save;
 603
 604         err = fcntl(fd, F_SETLK, &lock);
 605         if (!err)
 606                 goto out;
 607
 608         save = -errno;
 609         err = fcntl(fd, F_GETLK, &lock);
 610         if (err) {
 611                 err = -errno;
 612                 goto out;
 613         }
 614
 615         printk(UM_KERN_ERR "F_SETLK failed, file already locked by pid %d\n",
 616                lock.l_pid);
 617         err = save;
 618  out:
 619         return err;
 620 }
 621
 622 unsigned os_major(unsigned long long dev)
 623 {
 624         return major(dev);
 625 }
 626
 627 unsigned os_minor(unsigned long long dev)
 628 {
 629         return minor(dev);
 630 }
 631
 632 unsigned long long os_makedev(unsigned major, unsigned minor)
 633 {
 634         return makedev(major, minor);
 635 }
 636
 637 int os_falloc_punch(int fd, unsigned long long offset, int len)
 638 {
 639         int n = fallocate(fd, FALLOC_FL_PUNCH_HOLE|FALLOC_FL_KEEP_SIZE, offset, len);
 640
 641         if (n < 0)
 642                 return -errno;
 643         return n;
 644 }
 645
 646 int os_falloc_zeroes(int fd, unsigned long long offset, int len)
 647 {
 648         int n = fallocate(fd, FALLOC_FL_ZERO_RANGE|FALLOC_FL_KEEP_SIZE, offset, len);
 649
 650         if (n < 0)
 651                 return -errno;
 652         return n;
 653 }
 654
 655 int os_eventfd(unsigned int initval, int flags)
 656 {
 657         int fd = eventfd(initval, flags);
 658
 659         if (fd < 0)
 660                 return -errno;
 661         return fd;
 662 }
 663
 664 int os_sendmsg_fds(int fd, const void *buf, unsigned int len, const int *fds,
 665                    unsigned int fds_num)
 666 {
 667         struct iovec iov = {
 668                 .iov_base = (void *) buf,
 669                 .iov_len = len,
 670         };
 671         union {
 672                 char control[CMSG_SPACE(sizeof(*fds) * OS_SENDMSG_MAX_FDS)];
 673                 struct cmsghdr align;
 674         } u;
 675         unsigned int fds_size = sizeof(*fds) * fds_num;
 676         struct msghdr msg = {
 677                 .msg_iov = &iov,
 678                 .msg_iovlen = 1,
 679                 .msg_control = u.control,
 680                 .msg_controllen = CMSG_SPACE(fds_size),
 681         };
 682         struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msg);
 683         int err;
 684
 685         if (fds_num > OS_SENDMSG_MAX_FDS)
 686                 return -EINVAL;
 687         memset(u.control, 0, sizeof(u.control));
 688         cmsg->cmsg_level = SOL_SOCKET;
 689         cmsg->cmsg_type = SCM_RIGHTS;
 690         cmsg->cmsg_len = CMSG_LEN(fds_size);
 691         memcpy(CMSG_DATA(cmsg), fds, fds_size);
 692         err = sendmsg(fd, &msg, 0);
 693
 694         if (err < 0)
 695                 return -errno;
 696         return err;
 697 }
 698
 699 int os_poll(unsigned int n, const int *fds)
 700 {
 701         /* currently need 2 FDs at most so avoid dynamic allocation */
 702         struct pollfd pollfds[2] = {};
 703         unsigned int i;
 704         int ret;
 705
 706         if (n > ARRAY_SIZE(pollfds))
 707                 return -EINVAL;
 708
 709         for (i = 0; i < n; i++) {
 710                 pollfds[i].fd = fds[i];
 711                 pollfds[i].events = POLLIN;
 712         }
 713
 714         ret = poll(pollfds, n, -1);
 715         if (ret < 0)
 716                 return -errno;
 717
 718         /* Return the index of the available FD */
 719         for (i = 0; i < n; i++) {
 720                 if (pollfds[i].revents)
 721                         return i;
 722         }
 723
 724         return -EIO;
 725 }
 726
 727 void *os_mmap_rw_shared(int fd, size_t size)
 728 {
 729         void *res = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
 730
 731         if (res == MAP_FAILED)
 732                 return NULL;
 733
 734         return res;
 735 }
 736
 737 void *os_mremap_rw_shared(void *old_addr, size_t old_size, size_t new_size)
 738 {
 739         void *res;
 740
 741         res = mremap(old_addr, old_size, new_size, MREMAP_MAYMOVE, NULL);
 742
 743         if (res == MAP_FAILED)
 744                 return NULL;
 745
 746         return res;
 747 }