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                 return(fd);
 277
 278         err = connect(fd, (struct sockaddr *) &sock, sizeof(sock));
 279         if(err)
 280                 return(-errno);
 281
 282         return(fd);
 283 }
 284
 285 void os_close_file(int fd)
 286 {
 287         close(fd);
 288 }
 289
 290 int os_seek_file(int fd, __u64 offset)
 291 {
 292         __u64 actual;
 293
 294         actual = lseek64(fd, offset, SEEK_SET);
 295         if(actual != offset)
 296                 return(-errno);
 297         return(0);
 298 }
 299
 300 static int fault_buffer(void *start, int len,
 301                         int (*copy_proc)(void *addr, void *buf, int len))
 302 {
 303         int page = getpagesize(), i;
 304         char c;
 305
 306         for(i = 0; i < len; i += page){
 307                 if((*copy_proc)(start + i, &c, sizeof(c)))
 308                         return(-EFAULT);
 309         }
 310         if((len % page) != 0){
 311                 if((*copy_proc)(start + len - 1, &c, sizeof(c)))
 312                         return(-EFAULT);
 313         }
 314         return(0);
 315 }
 316
 317 static int file_io(int fd, void *buf, int len,
 318                    int (*io_proc)(int fd, void *buf, int len),
 319                    int (*copy_user_proc)(void *addr, void *buf, int len))
 320 {
 321         int n, err;
 322
 323         do {
 324                 n = (*io_proc)(fd, buf, len);
 325                 if((n < 0) && (errno == EFAULT)){
 326                         err = fault_buffer(buf, len, copy_user_proc);
 327                         if(err)
 328                                 return(err);
 329                         n = (*io_proc)(fd, buf, len);
 330                 }
 331         } while((n < 0) && (errno == EINTR));
 332
 333         if(n < 0)
 334                 return(-errno);
 335         return(n);
 336 }
 337
 338 int os_read_file(int fd, void *buf, int len)
 339 {
 340         return(file_io(fd, buf, len, (int (*)(int, void *, int)) read,
 341                        copy_from_user_proc));
 342 }
 343
 344 int os_write_file(int fd, const void *buf, int len)
 345 {
 346         return(file_io(fd, (void *) buf, len,
 347                        (int (*)(int, void *, int)) write, copy_to_user_proc));
 348 }
 349
 350 int os_file_size(char *file, unsigned long long *size_out)
 351 {
 352         struct uml_stat buf;
 353         int err;
 354
 355         err = os_stat_file(file, &buf);
 356         if(err < 0){
 357                 printk("Couldn't stat \"%s\" : err = %d\n", file, -err);
 358                 return(err);
 359         }
 360
 361         if(S_ISBLK(buf.ust_mode)){
 362                 int fd, blocks;
 363
 364                 fd = os_open_file(file, of_read(OPENFLAGS()), 0);
 365                 if(fd < 0){
 366                         printk("Couldn't open \"%s\", errno = %d\n", file, -fd);
 367                         return(fd);
 368                 }
 369                 if(ioctl(fd, BLKGETSIZE, &blocks) < 0){
 370                         err = -errno;
 371                         printk("Couldn't get the block size of \"%s\", "
 372                                "errno = %d\n", file, errno);
 373                         os_close_file(fd);
 374                         return(err);
 375                 }
 376                 *size_out = ((long long) blocks) * 512;
 377                 os_close_file(fd);
 378                 return(0);
 379         }
 380         *size_out = buf.ust_size;
 381         return(0);
 382 }
 383
 384 int os_file_modtime(char *file, unsigned long *modtime)
 385 {
 386         struct uml_stat buf;
 387         int err;
 388
 389         err = os_stat_file(file, &buf);
 390         if(err < 0){
 391                 printk("Couldn't stat \"%s\" : err = %d\n", file, -err);
 392                 return(err);
 393         }
 394
 395         *modtime = buf.ust_mtime;
 396         return(0);
 397 }
 398
 399 int os_get_exec_close(int fd, int* close_on_exec)
 400 {
 401         int ret;
 402
 403         do {
 404                 ret = fcntl(fd, F_GETFD);
 405         } while((ret < 0) && (errno == EINTR)) ;
 406
 407         if(ret < 0)
 408                 return(-errno);
 409
 410         *close_on_exec = (ret&FD_CLOEXEC) ? 1 : 0;
 411         return(ret);
 412 }
 413
 414 int os_set_exec_close(int fd, int close_on_exec)
 415 {
 416         int flag, err;
 417
 418         if(close_on_exec) flag = FD_CLOEXEC;
 419         else flag = 0;
 420
 421         do {
 422                 err = fcntl(fd, F_SETFD, flag);
 423         } while((err < 0) && (errno == EINTR)) ;
 424
 425         if(err < 0)
 426                 return(-errno);
 427         return(err);
 428 }
 429
 430 int os_pipe(int *fds, int stream, int close_on_exec)
 431 {
 432         int err, type = stream ? SOCK_STREAM : SOCK_DGRAM;
 433
 434         err = socketpair(AF_UNIX, type, 0, fds);
 435         if(err < 0)
 436                 return(-errno);
 437
 438         if(!close_on_exec)
 439                 return(0);
 440
 441         err = os_set_exec_close(fds[0], 1);
 442         if(err < 0)
 443                 goto error;
 444
 445         err = os_set_exec_close(fds[1], 1);
 446         if(err < 0)
 447                 goto error;
 448
 449         return(0);
 450
 451  error:
 452         printk("os_pipe : Setting FD_CLOEXEC failed, err = %d\n", -err);
 453         os_close_file(fds[1]);
 454         os_close_file(fds[0]);
 455         return(err);
 456 }
 457
 458 int os_set_fd_async(int fd, int owner)
 459 {
 460         int err;
 461
 462         /* XXX This should do F_GETFL first */
 463         if(fcntl(fd, F_SETFL, O_ASYNC | O_NONBLOCK) < 0){
 464                 err = -errno;
 465                 printk("os_set_fd_async : failed to set O_ASYNC and "
 466                        "O_NONBLOCK on fd # %d, errno = %d\n", fd, errno);
 467                 return err;
 468         }
 469 #ifdef notdef
 470         if(fcntl(fd, F_SETFD, 1) < 0){
 471                 printk("os_set_fd_async : Setting FD_CLOEXEC failed, "
 472                        "errno = %d\n", errno);
 473         }
 474 #endif
 475
 476         if((fcntl(fd, F_SETSIG, SIGIO) < 0) ||
 477            (fcntl(fd, F_SETOWN, owner) < 0)){
 478                 err = -errno;
 479                 printk("os_set_fd_async : Failed to fcntl F_SETOWN "
 480                        "(or F_SETSIG) fd %d to pid %d, errno = %d\n", fd,
 481                        owner, errno);
 482                 return err;
 483         }
 484
 485         return(0);
 486 }
 487
 488 int os_clear_fd_async(int fd)
 489 {
 490         int flags = fcntl(fd, F_GETFL);
 491
 492         flags &= ~(O_ASYNC | O_NONBLOCK);
 493         if(fcntl(fd, F_SETFL, flags) < 0)
 494                 return(-errno);
 495         return(0);
 496 }
 497
 498 int os_set_fd_block(int fd, int blocking)
 499 {
 500         int flags;
 501
 502         flags = fcntl(fd, F_GETFL);
 503
 504         if(blocking) flags &= ~O_NONBLOCK;
 505         else flags |= O_NONBLOCK;
 506
 507         if(fcntl(fd, F_SETFL, flags) < 0)
 508                 return -errno;
 509
 510         return(0);
 511 }
 512
 513 int os_accept_connection(int fd)
 514 {
 515         int new;
 516
 517         new = accept(fd, NULL, 0);
 518         if(new < 0)
 519                 return(-errno);
 520         return(new);
 521 }
 522
 523 #ifndef SHUT_RD
 524 #define SHUT_RD 0
 525 #endif
 526
 527 #ifndef SHUT_WR
 528 #define SHUT_WR 1
 529 #endif
 530
 531 #ifndef SHUT_RDWR
 532 #define SHUT_RDWR 2
 533 #endif
 534
 535 int os_shutdown_socket(int fd, int r, int w)
 536 {
 537         int what, err;
 538
 539         if(r && w) what = SHUT_RDWR;
 540         else if(r) what = SHUT_RD;
 541         else if(w) what = SHUT_WR;
 542         else {
 543                 printk("os_shutdown_socket : neither r or w was set\n");
 544                 return(-EINVAL);
 545         }
 546         err = shutdown(fd, what);
 547         if(err < 0)
 548                 return(-errno);
 549         return(0);
 550 }
 551
 552 int os_rcv_fd(int fd, int *helper_pid_out)
 553 {
 554         int new, n;
 555         char buf[CMSG_SPACE(sizeof(new))];
 556         struct msghdr msg;
 557         struct cmsghdr *cmsg;
 558         struct iovec iov;
 559
 560         msg.msg_name = NULL;
 561         msg.msg_namelen = 0;
 562         iov = ((struct iovec) { .iov_base  = helper_pid_out,
 563                                 .iov_len   = sizeof(*helper_pid_out) });
 564         msg.msg_iov = &iov;
 565         msg.msg_iovlen = 1;
 566         msg.msg_control = buf;
 567         msg.msg_controllen = sizeof(buf);
 568         msg.msg_flags = 0;
 569
 570         n = recvmsg(fd, &msg, 0);
 571         if(n < 0)
 572                 return(-errno);
 573
 574         else if(n != sizeof(iov.iov_len))
 575                 *helper_pid_out = -1;
 576
 577         cmsg = CMSG_FIRSTHDR(&msg);
 578         if(cmsg == NULL){
 579                 printk("rcv_fd didn't receive anything, error = %d\n", errno);
 580                 return(-1);
 581         }
 582         if((cmsg->cmsg_level != SOL_SOCKET) ||
 583            (cmsg->cmsg_type != SCM_RIGHTS)){
 584                 printk("rcv_fd didn't receive a descriptor\n");
 585                 return(-1);
 586         }
 587
 588         new = ((int *) CMSG_DATA(cmsg))[0];
 589         return(new);
 590 }
 591
 592 int os_create_unix_socket(char *file, int len, int close_on_exec)
 593 {
 594         struct sockaddr_un addr;
 595         int sock, err;
 596
 597         sock = socket(PF_UNIX, SOCK_DGRAM, 0);
 598         if(sock < 0)
 599                 return -errno;
 600
 601         if(close_on_exec) {
 602                 err = os_set_exec_close(sock, 1);
 603                 if(err < 0)
 604                         printk("create_unix_socket : close_on_exec failed, "
 605                        "err = %d", -err);
 606         }
 607
 608         addr.sun_family = AF_UNIX;
 609
 610         /* XXX Be more careful about overflow */
 611         snprintf(addr.sun_path, len, "%s", file);
 612
 613         err = bind(sock, (struct sockaddr *) &addr, sizeof(addr));
 614         if(err < 0)
 615                 return -errno;
 616
 617         return(sock);
 618 }
 619
 620 void os_flush_stdout(void)
 621 {
 622         fflush(stdout);
 623 }
 624
 625 int os_lock_file(int fd, int excl)
 626 {
 627         int type = excl ? F_WRLCK : F_RDLCK;
 628         struct flock lock = ((struct flock) { .l_type   = type,
 629                                               .l_whence = SEEK_SET,
 630                                               .l_start  = 0,
 631                                               .l_len    = 0 } );
 632         int err, save;
 633
 634         err = fcntl(fd, F_SETLK, &lock);
 635         if(!err)
 636                 goto out;
 637
 638         save = -errno;
 639         err = fcntl(fd, F_GETLK, &lock);
 640         if(err){
 641                 err = -errno;
 642                 goto out;
 643         }
 644
 645         printk("F_SETLK failed, file already locked by pid %d\n", lock.l_pid);
 646         err = save;
 647  out:
 648         return(err);
 649 }
 650
 651 /*
 652  * Overrides for Emacs so that we follow Linus's tabbing style.
 653  * Emacs will notice this stuff at the end of the file and automatically
 654  * adjust the settings for this buffer only.  This must remain at the end
 655  * of the file.
 656  * ---------------------------------------------------------------------------
 657  * Local variables:
 658  * c-file-style: "linux"
 659  * End:
 660  */