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