arch/um/os-Linux/file.c

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