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