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                 printk("TIOCSCTTY failed, errno = %d\n", errno);
 124                 return(-errno);
 125         }
 126
 127         if(tcsetpgrp(fd, pid) < 0){
 128                 printk("tcsetpgrp failed, errno = %d\n", errno);
 129                 return(-errno);
 130         }
 131
 132         return(0);
 133 }
 134
 135 /* FIXME: ensure namebuf in os_get_if_name is big enough */
 136 int os_get_ifname(int fd, char* namebuf)
 137 {
 138         if(ioctl(fd, SIOCGIFNAME, namebuf) < 0)
 139                 return(-errno);
 140
 141         return(0);
 142 }
 143
 144 int os_set_slip(int fd)
 145 {
 146         int disc, sencap;
 147
 148         disc = N_SLIP;
 149         if(ioctl(fd, TIOCSETD, &disc) < 0){
 150                 printk("Failed to set slip line discipline - "
 151                        "errno = %d\n", errno);
 152                 return(-errno);
 153         }
 154
 155         sencap = 0;
 156         if(ioctl(fd, SIOCSIFENCAP, &sencap) < 0){
 157                 printk("Failed to set slip encapsulation - "
 158                        "errno = %d\n", errno);
 159                 return(-errno);
 160         }
 161
 162         return(0);
 163 }
 164
 165 int os_set_owner(int fd, int pid)
 166 {
 167         if(fcntl(fd, F_SETOWN, pid) < 0){
 168                 int save_errno = errno;
 169
 170                 if(fcntl(fd, F_GETOWN, 0) != pid)
 171                         return(-save_errno);
 172         }
 173
 174         return(0);
 175 }
 176
 177 /* FIXME? moved wholesale from sigio_user.c to get fcntls out of that file */
 178 int os_sigio_async(int master, int slave)
 179 {
 180         int flags;
 181
 182         flags = fcntl(master, F_GETFL);
 183         if(flags < 0) {
 184                 printk("fcntl F_GETFL failed, errno = %d\n", errno);
 185                 return(-errno);
 186         }
 187
 188         if((fcntl(master, F_SETFL, flags | O_NONBLOCK | O_ASYNC) < 0) ||
 189            (fcntl(master, F_SETOWN, os_getpid()) < 0)){
 190                 printk("fcntl F_SETFL or F_SETOWN failed, errno = %d\n",
 191                        errno);
 192                 return(-errno);
 193         }
 194
 195         if((fcntl(slave, F_SETFL, flags | O_NONBLOCK) < 0)){
 196                 printk("fcntl F_SETFL failed, errno = %d\n", errno);
 197                 return(-errno);
 198         }
 199
 200         return(0);
 201 }
 202
 203 int os_mode_fd(int fd, int mode)
 204 {
 205         int err;
 206
 207         do {
 208                 err = fchmod(fd, mode);
 209         } while((err < 0) && (errno==EINTR)) ;
 210
 211         if(err < 0)
 212                 return(-errno);
 213
 214         return(0);
 215 }
 216
 217 int os_file_type(char *file)
 218 {
 219         struct uml_stat buf;
 220         int err;
 221
 222         err = os_stat_file(file, &buf);
 223         if(err < 0)
 224                 return(err);
 225
 226         if(S_ISDIR(buf.ust_mode)) return(OS_TYPE_DIR);
 227         else if(S_ISLNK(buf.ust_mode)) return(OS_TYPE_SYMLINK);
 228         else if(S_ISCHR(buf.ust_mode)) return(OS_TYPE_CHARDEV);
 229         else if(S_ISBLK(buf.ust_mode)) return(OS_TYPE_BLOCKDEV);
 230         else if(S_ISFIFO(buf.ust_mode)) return(OS_TYPE_FIFO);
 231         else if(S_ISSOCK(buf.ust_mode)) return(OS_TYPE_SOCK);
 232         else return(OS_TYPE_FILE);
 233 }
 234
 235 int os_file_mode(char *file, struct openflags *mode_out)
 236 {
 237         int err;
 238
 239         *mode_out = OPENFLAGS();
 240
 241         err = os_access(file, OS_ACC_W_OK);
 242         if((err < 0) && (err != -EACCES))
 243                 return(err);
 244
 245         *mode_out = of_write(*mode_out);
 246
 247         err = os_access(file, OS_ACC_R_OK);
 248         if((err < 0) && (err != -EACCES))
 249                 return(err);
 250
 251         *mode_out = of_read(*mode_out);
 252
 253         return(0);
 254 }
 255
 256 int os_open_file(char *file, struct openflags flags, int mode)
 257 {
 258         int fd, f = 0;
 259
 260         if(flags.r && flags.w) f = O_RDWR;
 261         else if(flags.r) f = O_RDONLY;
 262         else if(flags.w) f = O_WRONLY;
 263         else f = 0;
 264
 265         if(flags.s) f |= O_SYNC;
 266         if(flags.c) f |= O_CREAT;
 267         if(flags.t) f |= O_TRUNC;
 268         if(flags.e) f |= O_EXCL;
 269
 270         fd = open64(file, f, mode);
 271         if(fd < 0)
 272                 return(-errno);
 273
 274         if(flags.cl && fcntl(fd, F_SETFD, 1)){
 275                 os_close_file(fd);
 276                 return(-errno);
 277         }
 278
 279         return(fd);
 280 }
 281
 282 int os_connect_socket(char *name)
 283 {
 284         struct sockaddr_un sock;
 285         int fd, err;
 286
 287         sock.sun_family = AF_UNIX;
 288         snprintf(sock.sun_path, sizeof(sock.sun_path), "%s", name);
 289
 290         fd = socket(AF_UNIX, SOCK_STREAM, 0);
 291         if(fd < 0)
 292                 return(fd);
 293
 294         err = connect(fd, (struct sockaddr *) &sock, sizeof(sock));
 295         if(err)
 296                 return(-errno);
 297
 298         return(fd);
 299 }
 300
 301 void os_close_file(int fd)
 302 {
 303         close(fd);
 304 }
 305
 306 int os_seek_file(int fd, __u64 offset)
 307 {
 308         __u64 actual;
 309
 310         actual = lseek64(fd, offset, SEEK_SET);
 311         if(actual != offset)
 312                 return(-errno);
 313         return(0);
 314 }
 315
 316 static int fault_buffer(void *start, int len,
 317                         int (*copy_proc)(void *addr, void *buf, int len))
 318 {
 319         int page = getpagesize(), i;
 320         char c;
 321
 322         for(i = 0; i < len; i += page){
 323                 if((*copy_proc)(start + i, &c, sizeof(c)))
 324                         return(-EFAULT);
 325         }
 326         if((len % page) != 0){
 327                 if((*copy_proc)(start + len - 1, &c, sizeof(c)))
 328                         return(-EFAULT);
 329         }
 330         return(0);
 331 }
 332
 333 static int file_io(int fd, void *buf, int len,
 334                    int (*io_proc)(int fd, void *buf, int len),
 335                    int (*copy_user_proc)(void *addr, void *buf, int len))
 336 {
 337         int n, err;
 338
 339         do {
 340                 n = (*io_proc)(fd, buf, len);
 341                 if((n < 0) && (errno == EFAULT)){
 342                         err = fault_buffer(buf, len, copy_user_proc);
 343                         if(err)
 344                                 return(err);
 345                         n = (*io_proc)(fd, buf, len);
 346                 }
 347         } while((n < 0) && (errno == EINTR));
 348
 349         if(n < 0)
 350                 return(-errno);
 351         return(n);
 352 }
 353
 354 int os_read_file(int fd, void *buf, int len)
 355 {
 356         return(file_io(fd, buf, len, (int (*)(int, void *, int)) read,
 357                        copy_from_user_proc));
 358 }
 359
 360 int os_write_file(int fd, const void *buf, int len)
 361 {
 362         return(file_io(fd, (void *) buf, len,
 363                        (int (*)(int, void *, int)) write, copy_to_user_proc));
 364 }
 365
 366 int os_file_size(char *file, long long *size_out)
 367 {
 368         struct uml_stat buf;
 369         int err;
 370
 371         err = os_stat_file(file, &buf);
 372         if(err < 0){
 373                 printk("Couldn't stat \"%s\" : err = %d\n", file, -err);
 374                 return(err);
 375         }
 376
 377         if(S_ISBLK(buf.ust_mode)){
 378                 int fd, blocks;
 379
 380                 fd = os_open_file(file, of_read(OPENFLAGS()), 0);
 381                 if(fd < 0){
 382                         printk("Couldn't open \"%s\", errno = %d\n", file, -fd);
 383                         return(fd);
 384                 }
 385                 if(ioctl(fd, BLKGETSIZE, &blocks) < 0){
 386                         printk("Couldn't get the block size of \"%s\", "
 387                                "errno = %d\n", file, errno);
 388                         err = -errno;
 389                         os_close_file(fd);
 390                         return(err);
 391                 }
 392                 *size_out = ((long long) blocks) * 512;
 393                 os_close_file(fd);
 394                 return(0);
 395         }
 396         *size_out = buf.ust_size;
 397         return(0);
 398 }
 399
 400 int os_file_modtime(char *file, unsigned long *modtime)
 401 {
 402         struct uml_stat buf;
 403         int err;
 404
 405         err = os_stat_file(file, &buf);
 406         if(err < 0){
 407                 printk("Couldn't stat \"%s\" : err = %d\n", file, -err);
 408                 return(err);
 409         }
 410
 411         *modtime = buf.ust_mtime;
 412         return(0);
 413 }
 414
 415 int os_get_exec_close(int fd, int* close_on_exec)
 416 {
 417         int ret;
 418
 419         do {
 420                 ret = fcntl(fd, F_GETFD);
 421         } while((ret < 0) && (errno == EINTR)) ;
 422
 423         if(ret < 0)
 424                 return(-errno);
 425
 426         *close_on_exec = (ret&FD_CLOEXEC) ? 1 : 0;
 427         return(ret);
 428 }
 429
 430 int os_set_exec_close(int fd, int close_on_exec)
 431 {
 432         int flag, err;
 433
 434         if(close_on_exec) flag = FD_CLOEXEC;
 435         else flag = 0;
 436
 437         do {
 438                 err = fcntl(fd, F_SETFD, flag);
 439         } while((err < 0) && (errno == EINTR)) ;
 440
 441         if(err < 0)
 442                 return(-errno);
 443         return(err);
 444 }
 445
 446 int os_pipe(int *fds, int stream, int close_on_exec)
 447 {
 448         int err, type = stream ? SOCK_STREAM : SOCK_DGRAM;
 449
 450         err = socketpair(AF_UNIX, type, 0, fds);
 451         if(err < 0)
 452                 return(-errno);
 453
 454         if(!close_on_exec)
 455                 return(0);
 456
 457         err = os_set_exec_close(fds[0], 1);
 458         if(err < 0)
 459                 goto error;
 460
 461         err = os_set_exec_close(fds[1], 1);
 462         if(err < 0)
 463                 goto error;
 464
 465         return(0);
 466
 467  error:
 468         printk("os_pipe : Setting FD_CLOEXEC failed, err = %d\n", -err);
 469         os_close_file(fds[1]);
 470         os_close_file(fds[0]);
 471         return(err);
 472 }
 473
 474 int os_set_fd_async(int fd, int owner)
 475 {
 476         /* XXX This should do F_GETFL first */
 477         if(fcntl(fd, F_SETFL, O_ASYNC | O_NONBLOCK) < 0){
 478                 printk("os_set_fd_async : failed to set O_ASYNC and "
 479                        "O_NONBLOCK on fd # %d, errno = %d\n", fd, errno);
 480                 return(-errno);
 481         }
 482 #ifdef notdef
 483         if(fcntl(fd, F_SETFD, 1) < 0){
 484                 printk("os_set_fd_async : Setting FD_CLOEXEC failed, "
 485                        "errno = %d\n", errno);
 486         }
 487 #endif
 488
 489         if((fcntl(fd, F_SETSIG, SIGIO) < 0) ||
 490            (fcntl(fd, F_SETOWN, owner) < 0)){
 491                 printk("os_set_fd_async : Failed to fcntl F_SETOWN "
 492                        "(or F_SETSIG) fd %d to pid %d, errno = %d\n", fd,
 493                        owner, errno);
 494                 return(-errno);
 495         }
 496
 497         return(0);
 498 }
 499
 500 int os_clear_fd_async(int fd)
 501 {
 502         int flags = fcntl(fd, F_GETFL);
 503
 504         flags &= ~(O_ASYNC | O_NONBLOCK);
 505         if(fcntl(fd, F_SETFL, flags) < 0)
 506                 return(-errno);
 507         return(0);
 508 }
 509
 510 int os_set_fd_block(int fd, int blocking)
 511 {
 512         int flags;
 513
 514         flags = fcntl(fd, F_GETFL);
 515
 516         if(blocking) flags &= ~O_NONBLOCK;
 517         else flags |= O_NONBLOCK;
 518
 519         if(fcntl(fd, F_SETFL, flags) < 0){
 520                 printk("Failed to change blocking on fd # %d, errno = %d\n",
 521                        fd, errno);
 522                 return(-errno);
 523         }
 524         return(0);
 525 }
 526
 527 int os_accept_connection(int fd)
 528 {
 529         int new;
 530
 531         new = accept(fd, NULL, 0);
 532         if(new < 0)
 533                 return(-errno);
 534         return(new);
 535 }
 536
 537 #ifndef SHUT_RD
 538 #define SHUT_RD 0
 539 #endif
 540
 541 #ifndef SHUT_WR
 542 #define SHUT_WR 1
 543 #endif
 544
 545 #ifndef SHUT_RDWR
 546 #define SHUT_RDWR 2
 547 #endif
 548
 549 int os_shutdown_socket(int fd, int r, int w)
 550 {
 551         int what, err;
 552
 553         if(r && w) what = SHUT_RDWR;
 554         else if(r) what = SHUT_RD;
 555         else if(w) what = SHUT_WR;
 556         else {
 557                 printk("os_shutdown_socket : neither r or w was set\n");
 558                 return(-EINVAL);
 559         }
 560         err = shutdown(fd, what);
 561         if(err < 0)
 562                 return(-errno);
 563         return(0);
 564 }
 565
 566 int os_rcv_fd(int fd, int *helper_pid_out)
 567 {
 568         int new, n;
 569         char buf[CMSG_SPACE(sizeof(new))];
 570         struct msghdr msg;
 571         struct cmsghdr *cmsg;
 572         struct iovec iov;
 573
 574         msg.msg_name = NULL;
 575         msg.msg_namelen = 0;
 576         iov = ((struct iovec) { .iov_base  = helper_pid_out,
 577                                 .iov_len   = sizeof(*helper_pid_out) });
 578         msg.msg_iov = &iov;
 579         msg.msg_iovlen = 1;
 580         msg.msg_control = buf;
 581         msg.msg_controllen = sizeof(buf);
 582         msg.msg_flags = 0;
 583
 584         n = recvmsg(fd, &msg, 0);
 585         if(n < 0)
 586                 return(-errno);
 587
 588         else if(n != sizeof(iov.iov_len))
 589                 *helper_pid_out = -1;
 590
 591         cmsg = CMSG_FIRSTHDR(&msg);
 592         if(cmsg == NULL){
 593                 printk("rcv_fd didn't receive anything, error = %d\n", errno);
 594                 return(-1);
 595         }
 596         if((cmsg->cmsg_level != SOL_SOCKET) ||
 597            (cmsg->cmsg_type != SCM_RIGHTS)){
 598                 printk("rcv_fd didn't receive a descriptor\n");
 599                 return(-1);
 600         }
 601
 602         new = ((int *) CMSG_DATA(cmsg))[0];
 603         return(new);
 604 }
 605
 606 int os_create_unix_socket(char *file, int len, int close_on_exec)
 607 {
 608         struct sockaddr_un addr;
 609         int sock, err;
 610
 611         sock = socket(PF_UNIX, SOCK_DGRAM, 0);
 612         if (sock < 0){
 613                 printk("create_unix_socket - socket failed, errno = %d\n",
 614                        errno);
 615                 return(-errno);
 616         }
 617
 618         if(close_on_exec) {
 619                 err = os_set_exec_close(sock, 1);
 620                 if(err < 0)
 621                         printk("create_unix_socket : close_on_exec failed, "
 622                        "err = %d", -err);
 623         }
 624
 625         addr.sun_family = AF_UNIX;
 626
 627         /* XXX Be more careful about overflow */
 628         snprintf(addr.sun_path, len, "%s", file);
 629
 630         err = bind(sock, (struct sockaddr *) &addr, sizeof(addr));
 631         if (err < 0){
 632                 printk("create_listening_socket at '%s' - bind failed, "
 633                        "errno = %d\n", file, errno);
 634                 return(-errno);
 635         }
 636
 637         return(sock);
 638 }
 639
 640 void os_flush_stdout(void)
 641 {
 642         fflush(stdout);
 643 }
 644
 645 int os_lock_file(int fd, int excl)
 646 {
 647         int type = excl ? F_WRLCK : F_RDLCK;
 648         struct flock lock = ((struct flock) { .l_type   = type,
 649                                               .l_whence = SEEK_SET,
 650                                               .l_start  = 0,
 651                                               .l_len    = 0 } );
 652         int err, save;
 653
 654         err = fcntl(fd, F_SETLK, &lock);
 655         if(!err)
 656                 goto out;
 657
 658         save = -errno;
 659         err = fcntl(fd, F_GETLK, &lock);
 660         if(err){
 661                 err = -errno;
 662                 goto out;
 663         }
 664
 665         printk("F_SETLK failed, file already locked by pid %d\n", lock.l_pid);
 666         err = save;
 667  out:
 668         return(err);
 669 }
 670
 671 /*
 672  * Overrides for Emacs so that we follow Linus's tabbing style.
 673  * Emacs will notice this stuff at the end of the file and automatically
 674  * adjust the settings for this buffer only.  This must remain at the end
 675  * of the file.
 676  * ---------------------------------------------------------------------------
 677  * Local variables:
 678  * c-file-style: "linux"
 679  * End:
 680  */