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