arch/um/os-Linux/file.c

   1 /*
   2  * Copyright (C) 2002 Jeff Dike (jdike@karaya.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/types.h>
  12 #include <sys/stat.h>
  13 #include <sys/socket.h>
  14 #include <sys/un.h>
  15 #include <sys/ioctl.h>
  16 #include <sys/mount.h>
  17 #include <sys/uio.h>
  18 #include "os.h"
  19 #include "user.h"
  20 #include "kern_util.h"
  21
  22 static void copy_stat(struct uml_stat *dst, struct stat64 *src)
  23 {
  24         *dst = ((struct uml_stat) {
  25                 .ust_dev     = src->st_dev,     /* device */
  26                 .ust_ino     = src->st_ino,     /* inode */
  27                 .ust_mode    = src->st_mode,    /* protection */
  28                 .ust_nlink   = src->st_nlink,   /* number of hard links */
  29                 .ust_uid     = src->st_uid,     /* user ID of owner */
  30                 .ust_gid     = src->st_gid,     /* group ID of owner */
  31                 .ust_size    = src->st_size,    /* total size, in bytes */
  32                 .ust_blksize = src->st_blksize, /* blocksize for filesys I/O */
  33                 .ust_blocks  = src->st_blocks,  /* number of blocks allocated */
  34                 .ust_atime   = src->st_atime,   /* time of last access */
  35                 .ust_mtime   = src->st_mtime,   /* time of last modification */
  36                 .ust_ctime   = src->st_ctime,   /* time of last change */
  37         });
  38 }
  39
  40 int os_stat_fd(const int fd, struct uml_stat *ubuf)
  41 {
  42         struct stat64 sbuf;
  43         int err;
  44
  45         do {
  46                 err = fstat64(fd, &sbuf);
  47         } while((err < 0) && (errno == EINTR)) ;
  48
  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         do {
  63                 err = stat64(file_name, &sbuf);
  64         } while((err < 0) && (errno == EINTR)) ;
  65
  66         if(err < 0)
  67                 return(-errno);
  68
  69         if(ubuf != NULL)
  70                 copy_stat(ubuf, &sbuf);
  71         return(err);
  72 }
  73
  74 int os_access(const char* file, int mode)
  75 {
  76         int amode, err;
  77
  78         amode=(mode&OS_ACC_R_OK ? R_OK : 0) | (mode&OS_ACC_W_OK ? W_OK : 0) |
  79               (mode&OS_ACC_X_OK ? X_OK : 0) | (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 void os_print_error(int error, const char* str)
  89 {
  90         errno = error < 0 ? -error : error;
  91
  92         perror(str);
  93 }
  94
  95 /* FIXME? required only by hostaudio (because it passes ioctls verbatim) */
  96 int os_ioctl_generic(int fd, unsigned int cmd, unsigned long arg)
  97 {
  98         int err;
  99
 100         err = ioctl(fd, cmd, arg);
 101         if(err < 0)
 102                 return(-errno);
 103
 104         return(err);
 105 }
 106
 107 int os_window_size(int fd, int *rows, int *cols)
 108 {
 109         struct winsize size;
 110
 111         if(ioctl(fd, TIOCGWINSZ, &size) < 0)
 112                 return(-errno);
 113
 114         *rows = size.ws_row;
 115         *cols = size.ws_col;
 116
 117         return(0);
 118 }
 119
 120 int os_new_tty_pgrp(int fd, int pid)
 121 {
 122         if(ioctl(fd, TIOCSCTTY, 0) < 0)
 123                 return -errno;
 124
 125         if(tcsetpgrp(fd, pid) < 0)
 126                 return -errno;
 127
 128         return(0);
 129 }
 130
 131 /* FIXME: ensure namebuf in os_get_if_name is big enough */
 132 int os_get_ifname(int fd, char* namebuf)
 133 {
 134         if(ioctl(fd, SIOCGIFNAME, namebuf) < 0)
 135                 return(-errno);
 136
 137         return(0);
 138 }
 139
 140 int os_set_slip(int fd)
 141 {
 142         int disc, sencap;
 143
 144         disc = N_SLIP;
 145         if(ioctl(fd, TIOCSETD, &disc) < 0)
 146                 return -errno;
 147
 148         sencap = 0;
 149         if(ioctl(fd, SIOCSIFENCAP, &sencap) < 0)
 150                 return -errno;
 151
 152         return(0);
 153 }
 154
 155 int os_set_owner(int fd, int pid)
 156 {
 157         if(fcntl(fd, F_SETOWN, pid) < 0){
 158                 int save_errno = errno;
 159
 160                 if(fcntl(fd, F_GETOWN, 0) != pid)
 161                         return(-save_errno);
 162         }
 163
 164         return(0);
 165 }
 166
 167 /* FIXME? moved wholesale from sigio_user.c to get fcntls out of that file */
 168 int os_sigio_async(int master, int slave)
 169 {
 170         int flags;
 171
 172         flags = fcntl(master, F_GETFL);
 173         if(flags < 0)
 174                 return -errno;
 175
 176         if((fcntl(master, F_SETFL, flags | O_NONBLOCK | O_ASYNC) < 0) ||
 177            (fcntl(master, F_SETOWN, os_getpid()) < 0))
 178                 return -errno;
 179
 180         if((fcntl(slave, F_SETFL, flags | O_NONBLOCK) < 0))
 181                 return -errno;
 182
 183         return(0);
 184 }
 185
 186 int os_mode_fd(int fd, int mode)
 187 {
 188         int err;
 189
 190         do {
 191                 err = fchmod(fd, mode);
 192         } while((err < 0) && (errno==EINTR)) ;
 193
 194         if(err < 0)
 195                 return(-errno);
 196
 197         return(0);
 198 }
 199
 200 int os_file_type(char *file)
 201 {
 202         struct uml_stat buf;
 203         int err;
 204
 205         err = os_stat_file(file, &buf);
 206         if(err < 0)
 207                 return(err);
 208
 209         if(S_ISDIR(buf.ust_mode)) return(OS_TYPE_DIR);
 210         else if(S_ISLNK(buf.ust_mode)) return(OS_TYPE_SYMLINK);
 211         else if(S_ISCHR(buf.ust_mode)) return(OS_TYPE_CHARDEV);
 212         else if(S_ISBLK(buf.ust_mode)) return(OS_TYPE_BLOCKDEV);
 213         else if(S_ISFIFO(buf.ust_mode)) return(OS_TYPE_FIFO);
 214         else if(S_ISSOCK(buf.ust_mode)) return(OS_TYPE_SOCK);
 215         else return(OS_TYPE_FILE);
 216 }
 217
 218 int os_file_mode(char *file, struct openflags *mode_out)
 219 {
 220         int err;
 221
 222         *mode_out = OPENFLAGS();
 223
 224         err = os_access(file, OS_ACC_W_OK);
 225         if((err < 0) && (err != -EACCES))
 226                 return(err);
 227
 228         *mode_out = of_write(*mode_out);
 229
 230         err = os_access(file, OS_ACC_R_OK);
 231         if((err < 0) && (err != -EACCES))
 232                 return(err);
 233
 234         *mode_out = of_read(*mode_out);
 235
 236         return(0);
 237 }
 238
 239 int os_open_file(char *file, struct openflags flags, int mode)
 240 {
 241         int fd, err, f = 0;
 242
 243         if(flags.r && flags.w) f = O_RDWR;
 244         else if(flags.r) f = O_RDONLY;
 245         else if(flags.w) f = O_WRONLY;
 246         else f = 0;
 247
 248         if(flags.s) f |= O_SYNC;
 249         if(flags.c) f |= O_CREAT;
 250         if(flags.t) f |= O_TRUNC;
 251         if(flags.e) f |= O_EXCL;
 252
 253         fd = open64(file, f, mode);
 254         if(fd < 0)
 255                 return(-errno);
 256
 257         if(flags.cl && fcntl(fd, F_SETFD, 1)){
 258                 err = -errno;
 259                 os_close_file(fd);
 260                 return err;
 261         }
 262
 263         return(fd);
 264 }
 265
 266 int os_connect_socket(char *name)
 267 {
 268         struct sockaddr_un sock;
 269         int fd, err;
 270
 271         sock.sun_family = AF_UNIX;
 272         snprintf(sock.sun_path, sizeof(sock.sun_path), "%s", name);
 273
 274         fd = socket(AF_UNIX, SOCK_STREAM, 0);
 275         if(fd < 0) {
 276                 err = -errno;
 277                 goto out;
 278         }
 279
 280         err = connect(fd, (struct sockaddr *) &sock, sizeof(sock));
 281         if(err) {
 282                 err = -errno;
 283                 goto out_close;
 284         }
 285
 286         return fd;
 287
 288 out_close:
 289         close(fd);
 290 out:
 291         return err;
 292 }
 293
 294 void os_close_file(int fd)
 295 {
 296         close(fd);
 297 }
 298
 299 int os_seek_file(int fd, __u64 offset)
 300 {
 301         __u64 actual;
 302
 303         actual = lseek64(fd, offset, SEEK_SET);
 304         if(actual != offset)
 305                 return(-errno);
 306         return(0);
 307 }
 308
 309 static int fault_buffer(void *start, int len,
 310                         int (*copy_proc)(void *addr, void *buf, int len))
 311 {
 312         int page = getpagesize(), i;
 313         char c;
 314
 315         for(i = 0; i < len; i += page){
 316                 if((*copy_proc)(start + i, &c, sizeof(c)))
 317                         return(-EFAULT);
 318         }
 319         if((len % page) != 0){
 320                 if((*copy_proc)(start + len - 1, &c, sizeof(c)))
 321                         return(-EFAULT);
 322         }
 323         return(0);
 324 }
 325
 326 static int file_io(int fd, void *buf, int len,
 327                    int (*io_proc)(int fd, void *buf, int len),
 328                    int (*copy_user_proc)(void *addr, void *buf, int len))
 329 {
 330         int n, err;
 331
 332         do {
 333                 n = (*io_proc)(fd, buf, len);
 334                 if((n < 0) && (errno == EFAULT)){
 335                         err = fault_buffer(buf, len, copy_user_proc);
 336                         if(err)
 337                                 return(err);
 338                         n = (*io_proc)(fd, buf, len);
 339                 }
 340         } while((n < 0) && (errno == EINTR));
 341
 342         if(n < 0)
 343                 return(-errno);
 344         return(n);
 345 }
 346
 347 int os_read_file(int fd, void *buf, int len)
 348 {
 349         return(file_io(fd, buf, len, (int (*)(int, void *, int)) read,
 350                        copy_from_user_proc));
 351 }
 352
 353 int os_write_file(int fd, const void *buf, int len)
 354 {
 355         return(file_io(fd, (void *) buf, len,
 356                        (int (*)(int, void *, int)) write, copy_to_user_proc));
 357 }
 358
 359 int os_file_size(char *file, unsigned long long *size_out)
 360 {
 361         struct uml_stat buf;
 362         int err;
 363
 364         err = os_stat_file(file, &buf);
 365         if(err < 0){
 366                 printk("Couldn't stat \"%s\" : err = %d\n", file, -err);
 367                 return(err);
 368         }
 369
 370         if(S_ISBLK(buf.ust_mode)){
 371                 int fd, blocks;
 372
 373                 fd = os_open_file(file, of_read(OPENFLAGS()), 0);
 374                 if(fd < 0){
 375                         printk("Couldn't open \"%s\", errno = %d\n", file, -fd);
 376                         return(fd);
 377                 }
 378                 if(ioctl(fd, BLKGETSIZE, &blocks) < 0){
 379                         err = -errno;
 380                         printk("Couldn't get the block size of \"%s\", "
 381                                "errno = %d\n", file, errno);
 382                         os_close_file(fd);
 383                         return(err);
 384                 }
 385                 *size_out = ((long long) blocks) * 512;
 386                 os_close_file(fd);
 387                 return(0);
 388         }
 389         *size_out = buf.ust_size;
 390         return(0);
 391 }
 392
 393 int os_file_modtime(char *file, unsigned long *modtime)
 394 {
 395         struct uml_stat buf;
 396         int err;
 397
 398         err = os_stat_file(file, &buf);
 399         if(err < 0){
 400                 printk("Couldn't stat \"%s\" : err = %d\n", file, -err);
 401                 return(err);
 402         }
 403
 404         *modtime = buf.ust_mtime;
 405         return(0);
 406 }
 407
 408 int os_get_exec_close(int fd, int* close_on_exec)
 409 {
 410         int ret;
 411
 412         do {
 413                 ret = fcntl(fd, F_GETFD);
 414         } while((ret < 0) && (errno == EINTR)) ;
 415
 416         if(ret < 0)
 417                 return(-errno);
 418
 419         *close_on_exec = (ret&FD_CLOEXEC) ? 1 : 0;
 420         return(ret);
 421 }
 422
 423 int os_set_exec_close(int fd, int close_on_exec)
 424 {
 425         int flag, err;
 426
 427         if(close_on_exec) flag = FD_CLOEXEC;
 428         else flag = 0;
 429
 430         do {
 431                 err = fcntl(fd, F_SETFD, flag);
 432         } while((err < 0) && (errno == EINTR)) ;
 433
 434         if(err < 0)
 435                 return(-errno);
 436         return(err);
 437 }
 438
 439 int os_pipe(int *fds, int stream, int close_on_exec)
 440 {
 441         int err, type = stream ? SOCK_STREAM : SOCK_DGRAM;
 442
 443         err = socketpair(AF_UNIX, type, 0, fds);
 444         if(err < 0)
 445                 return(-errno);
 446
 447         if(!close_on_exec)
 448                 return(0);
 449
 450         err = os_set_exec_close(fds[0], 1);
 451         if(err < 0)
 452                 goto error;
 453
 454         err = os_set_exec_close(fds[1], 1);
 455         if(err < 0)
 456                 goto error;
 457
 458         return(0);
 459
 460  error:
 461         printk("os_pipe : Setting FD_CLOEXEC failed, err = %d\n", -err);
 462         os_close_file(fds[1]);
 463         os_close_file(fds[0]);
 464         return(err);
 465 }
 466
 467 int os_set_fd_async(int fd, int owner)
 468 {
 469         int err;
 470
 471         /* XXX This should do F_GETFL first */
 472         if(fcntl(fd, F_SETFL, O_ASYNC | O_NONBLOCK) < 0){
 473                 err = -errno;
 474                 printk("os_set_fd_async : failed to set O_ASYNC and "
 475                        "O_NONBLOCK on fd # %d, errno = %d\n", fd, errno);
 476                 return err;
 477         }
 478 #ifdef notdef
 479         if(fcntl(fd, F_SETFD, 1) < 0){
 480                 printk("os_set_fd_async : Setting FD_CLOEXEC failed, "
 481                        "errno = %d\n", errno);
 482         }
 483 #endif
 484
 485         if((fcntl(fd, F_SETSIG, SIGIO) < 0) ||
 486            (fcntl(fd, F_SETOWN, owner) < 0)){
 487                 err = -errno;
 488                 printk("os_set_fd_async : Failed to fcntl F_SETOWN "
 489                        "(or F_SETSIG) fd %d to pid %d, errno = %d\n", fd,
 490                        owner, errno);
 491                 return err;
 492         }
 493
 494         return(0);
 495 }
 496
 497 int os_clear_fd_async(int fd)
 498 {
 499         int flags = fcntl(fd, F_GETFL);
 500
 501         flags &= ~(O_ASYNC | O_NONBLOCK);
 502         if(fcntl(fd, F_SETFL, flags) < 0)
 503                 return(-errno);
 504         return(0);
 505 }
 506
 507 int os_set_fd_block(int fd, int blocking)
 508 {
 509         int flags;
 510
 511         flags = fcntl(fd, F_GETFL);
 512
 513         if(blocking) flags &= ~O_NONBLOCK;
 514         else flags |= O_NONBLOCK;
 515
 516         if(fcntl(fd, F_SETFL, flags) < 0)
 517                 return -errno;
 518
 519         return(0);
 520 }
 521
 522 int os_accept_connection(int fd)
 523 {
 524         int new;
 525
 526         new = accept(fd, NULL, 0);
 527         if(new < 0)
 528                 return(-errno);
 529         return(new);
 530 }
 531
 532 #ifndef SHUT_RD
 533 #define SHUT_RD 0
 534 #endif
 535
 536 #ifndef SHUT_WR
 537 #define SHUT_WR 1
 538 #endif
 539
 540 #ifndef SHUT_RDWR
 541 #define SHUT_RDWR 2
 542 #endif
 543
 544 int os_shutdown_socket(int fd, int r, int w)
 545 {
 546         int what, err;
 547
 548         if(r && w) what = SHUT_RDWR;
 549         else if(r) what = SHUT_RD;
 550         else if(w) what = SHUT_WR;
 551         else {
 552                 printk("os_shutdown_socket : neither r or w was set\n");
 553                 return(-EINVAL);
 554         }
 555         err = shutdown(fd, what);
 556         if(err < 0)
 557                 return(-errno);
 558         return(0);
 559 }
 560
 561 int os_rcv_fd(int fd, int *helper_pid_out)
 562 {
 563         int new, n;
 564         char buf[CMSG_SPACE(sizeof(new))];
 565         struct msghdr msg;
 566         struct cmsghdr *cmsg;
 567         struct iovec iov;
 568
 569         msg.msg_name = NULL;
 570         msg.msg_namelen = 0;
 571         iov = ((struct iovec) { .iov_base  = helper_pid_out,
 572                                 .iov_len   = sizeof(*helper_pid_out) });
 573         msg.msg_iov = &iov;
 574         msg.msg_iovlen = 1;
 575         msg.msg_control = buf;
 576         msg.msg_controllen = sizeof(buf);
 577         msg.msg_flags = 0;
 578
 579         n = recvmsg(fd, &msg, 0);
 580         if(n < 0)
 581                 return(-errno);
 582
 583         else if(n != sizeof(iov.iov_len))
 584                 *helper_pid_out = -1;
 585
 586         cmsg = CMSG_FIRSTHDR(&msg);
 587         if(cmsg == NULL){
 588                 printk("rcv_fd didn't receive anything, error = %d\n", errno);
 589                 return(-1);
 590         }
 591         if((cmsg->cmsg_level != SOL_SOCKET) ||
 592            (cmsg->cmsg_type != SCM_RIGHTS)){
 593                 printk("rcv_fd didn't receive a descriptor\n");
 594                 return(-1);
 595         }
 596
 597         new = ((int *) CMSG_DATA(cmsg))[0];
 598         return(new);
 599 }
 600
 601 int os_create_unix_socket(char *file, int len, int close_on_exec)
 602 {
 603         struct sockaddr_un addr;
 604         int sock, err;
 605
 606         sock = socket(PF_UNIX, SOCK_DGRAM, 0);
 607         if(sock < 0)
 608                 return -errno;
 609
 610         if(close_on_exec) {
 611                 err = os_set_exec_close(sock, 1);
 612                 if(err < 0)
 613                         printk("create_unix_socket : close_on_exec failed, "
 614                        "err = %d", -err);
 615         }
 616
 617         addr.sun_family = AF_UNIX;
 618
 619         /* XXX Be more careful about overflow */
 620         snprintf(addr.sun_path, len, "%s", file);
 621
 622         err = bind(sock, (struct sockaddr *) &addr, sizeof(addr));
 623         if(err < 0)
 624                 return -errno;
 625
 626         return(sock);
 627 }
 628
 629 void os_flush_stdout(void)
 630 {
 631         fflush(stdout);
 632 }
 633
 634 int os_lock_file(int fd, int excl)
 635 {
 636         int type = excl ? F_WRLCK : F_RDLCK;
 637         struct flock lock = ((struct flock) { .l_type   = type,
 638                                               .l_whence = SEEK_SET,
 639                                               .l_start  = 0,
 640                                               .l_len    = 0 } );
 641         int err, save;
 642
 643         err = fcntl(fd, F_SETLK, &lock);
 644         if(!err)
 645                 goto out;
 646
 647         save = -errno;
 648         err = fcntl(fd, F_GETLK, &lock);
 649         if(err){
 650                 err = -errno;
 651                 goto out;
 652         }
 653
 654         printk("F_SETLK failed, file already locked by pid %d\n", lock.l_pid);
 655         err = save;
 656  out:
 657         return(err);
 658 }
 659
 660 /*
 661  * Overrides for Emacs so that we follow Linus's tabbing style.
 662  * Emacs will notice this stuff at the end of the file and automatically
 663  * adjust the settings for this buffer only.  This must remain at the end
 664  * of the file.
 665  * ---------------------------------------------------------------------------
 666  * Local variables:
 667  * c-file-style: "linux"
 668  * End:
 669  */