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 #include "user_util.h"
  22
  23 static void copy_stat(struct uml_stat *dst, struct stat64 *src)
  24 {
  25         *dst = ((struct uml_stat) {
  26                 .ust_dev     = src->st_dev,     /* device */
  27                 .ust_ino     = src->st_ino,     /* inode */
  28                 .ust_mode    = src->st_mode,    /* protection */
  29                 .ust_nlink   = src->st_nlink,   /* number of hard links */
  30                 .ust_uid     = src->st_uid,     /* user ID of owner */
  31                 .ust_gid     = src->st_gid,     /* group ID of owner */
  32                 .ust_size    = src->st_size,    /* total size, in bytes */
  33                 .ust_blksize = src->st_blksize, /* blocksize for filesys I/O */
  34                 .ust_blocks  = src->st_blocks,  /* number of blocks allocated */
  35                 .ust_atime   = src->st_atime,   /* time of last access */
  36                 .ust_mtime   = src->st_mtime,   /* time of last modification */
  37                 .ust_ctime   = src->st_ctime,   /* time of last change */
  38         });
  39 }
  40
  41 int os_stat_fd(const int fd, struct uml_stat *ubuf)
  42 {
  43         struct stat64 sbuf;
  44         int err;
  45
  46         CATCH_EINTR(err = fstat64(fd, &sbuf));
  47         if(err < 0)
  48                 return -errno;
  49
  50         if(ubuf != NULL)
  51                 copy_stat(ubuf, &sbuf);
  52         return err;
  53 }
  54
  55 int os_stat_file(const char *file_name, struct uml_stat *ubuf)
  56 {
  57         struct stat64 sbuf;
  58         int err;
  59
  60         do {
  61                 err = stat64(file_name, &sbuf);
  62         } while((err < 0) && (errno == EINTR)) ;
  63
  64         if(err < 0)
  65                 return -errno;
  66
  67         if(ubuf != NULL)
  68                 copy_stat(ubuf, &sbuf);
  69         return err;
  70 }
  71
  72 int os_access(const char* file, int mode)
  73 {
  74         int amode, err;
  75
  76         amode=(mode&OS_ACC_R_OK ? R_OK : 0) | (mode&OS_ACC_W_OK ? W_OK : 0) |
  77               (mode&OS_ACC_X_OK ? X_OK : 0) | (mode&OS_ACC_F_OK ? F_OK : 0) ;
  78
  79         err = access(file, amode);
  80         if(err < 0)
  81                 return -errno;
  82
  83         return 0;
  84 }
  85
  86 void os_print_error(int error, const char* str)
  87 {
  88         errno = error < 0 ? -error : error;
  89
  90         perror(str);
  91 }
  92
  93 /* FIXME? required only by hostaudio (because it passes ioctls verbatim) */
  94 int os_ioctl_generic(int fd, unsigned int cmd, unsigned long arg)
  95 {
  96         int err;
  97
  98         err = ioctl(fd, cmd, arg);
  99         if(err < 0)
 100                 return -errno;
 101
 102         return err;
 103 }
 104
 105 int os_window_size(int fd, int *rows, int *cols)
 106 {
 107         struct winsize size;
 108
 109         if(ioctl(fd, TIOCGWINSZ, &size) < 0)
 110                 return -errno;
 111
 112         *rows = size.ws_row;
 113         *cols = size.ws_col;
 114
 115         return 0;
 116 }
 117
 118 int os_new_tty_pgrp(int fd, int pid)
 119 {
 120         if(ioctl(fd, TIOCSCTTY, 0) < 0)
 121                 return -errno;
 122
 123         if(tcsetpgrp(fd, pid) < 0)
 124                 return -errno;
 125
 126         return 0;
 127 }
 128
 129 /* FIXME: ensure namebuf in os_get_if_name is big enough */
 130 int os_get_ifname(int fd, char* namebuf)
 131 {
 132         if(ioctl(fd, SIOCGIFNAME, namebuf) < 0)
 133                 return -errno;
 134
 135         return 0;
 136 }
 137
 138 int os_set_slip(int fd)
 139 {
 140         int disc, sencap;
 141
 142         disc = N_SLIP;
 143         if(ioctl(fd, TIOCSETD, &disc) < 0)
 144                 return -errno;
 145
 146         sencap = 0;
 147         if(ioctl(fd, SIOCSIFENCAP, &sencap) < 0)
 148                 return -errno;
 149
 150         return 0;
 151 }
 152
 153 int os_set_owner(int fd, int pid)
 154 {
 155         if(fcntl(fd, F_SETOWN, pid) < 0){
 156                 int save_errno = errno;
 157
 158                 if(fcntl(fd, F_GETOWN, 0) != pid)
 159                         return -save_errno;
 160         }
 161
 162         return 0;
 163 }
 164
 165 /* FIXME? moved wholesale from sigio_user.c to get fcntls out of that file */
 166 int os_sigio_async(int master, int slave)
 167 {
 168         int flags;
 169
 170         flags = fcntl(master, F_GETFL);
 171         if(flags < 0)
 172                 return -errno;
 173
 174         if((fcntl(master, F_SETFL, flags | O_NONBLOCK | O_ASYNC) < 0) ||
 175            (fcntl(master, F_SETOWN, os_getpid()) < 0))
 176                 return -errno;
 177
 178         if((fcntl(slave, F_SETFL, flags | O_NONBLOCK) < 0))
 179                 return -errno;
 180
 181         return(0);
 182 }
 183
 184 int os_mode_fd(int fd, int mode)
 185 {
 186         int err;
 187
 188         do {
 189                 err = fchmod(fd, mode);
 190         } while((err < 0) && (errno==EINTR)) ;
 191
 192         if(err < 0)
 193                 return -errno;
 194
 195         return 0;
 196 }
 197
 198 int os_file_type(char *file)
 199 {
 200         struct uml_stat buf;
 201         int err;
 202
 203         err = os_stat_file(file, &buf);
 204         if(err < 0)
 205                 return err;
 206
 207         if(S_ISDIR(buf.ust_mode))
 208                 return OS_TYPE_DIR;
 209         else if(S_ISLNK(buf.ust_mode))
 210                 return OS_TYPE_SYMLINK;
 211         else if(S_ISCHR(buf.ust_mode))
 212                 return OS_TYPE_CHARDEV;
 213         else if(S_ISBLK(buf.ust_mode))
 214                 return OS_TYPE_BLOCKDEV;
 215         else if(S_ISFIFO(buf.ust_mode))
 216                 return OS_TYPE_FIFO;
 217         else if(S_ISSOCK(buf.ust_mode))
 218                 return OS_TYPE_SOCK;
 219         else return OS_TYPE_FILE;
 220 }
 221
 222 int os_file_mode(char *file, struct openflags *mode_out)
 223 {
 224         int err;
 225
 226         *mode_out = OPENFLAGS();
 227
 228         err = os_access(file, OS_ACC_W_OK);
 229         if((err < 0) && (err != -EACCES))
 230                 return(err);
 231
 232         *mode_out = of_write(*mode_out);
 233
 234         err = os_access(file, OS_ACC_R_OK);
 235         if((err < 0) && (err != -EACCES))
 236                 return(err);
 237
 238         *mode_out = of_read(*mode_out);
 239
 240         return(0);
 241 }
 242
 243 int os_open_file(char *file, struct openflags flags, int mode)
 244 {
 245         int fd, err, f = 0;
 246
 247         if(flags.r && flags.w) f = O_RDWR;
 248         else if(flags.r) f = O_RDONLY;
 249         else if(flags.w) f = O_WRONLY;
 250         else f = 0;
 251
 252         if(flags.s) f |= O_SYNC;
 253         if(flags.c) f |= O_CREAT;
 254         if(flags.t) f |= O_TRUNC;
 255         if(flags.e) f |= O_EXCL;
 256
 257         fd = open64(file, f, mode);
 258         if(fd < 0)
 259                 return(-errno);
 260
 261         if(flags.cl && fcntl(fd, F_SETFD, 1)){
 262                 err = -errno;
 263                 os_close_file(fd);
 264                 return err;
 265         }
 266
 267         return(fd);
 268 }
 269
 270 int os_connect_socket(char *name)
 271 {
 272         struct sockaddr_un sock;
 273         int fd, err;
 274
 275         sock.sun_family = AF_UNIX;
 276         snprintf(sock.sun_path, sizeof(sock.sun_path), "%s", name);
 277
 278         fd = socket(AF_UNIX, SOCK_STREAM, 0);
 279         if(fd < 0) {
 280                 err = -errno;
 281                 goto out;
 282         }
 283
 284         err = connect(fd, (struct sockaddr *) &sock, sizeof(sock));
 285         if(err) {
 286                 err = -errno;
 287                 goto out_close;
 288         }
 289
 290         return fd;
 291
 292 out_close:
 293         close(fd);
 294 out:
 295         return err;
 296 }
 297
 298 void os_close_file(int fd)
 299 {
 300         close(fd);
 301 }
 302
 303 int os_seek_file(int fd, __u64 offset)
 304 {
 305         __u64 actual;
 306
 307         actual = lseek64(fd, offset, SEEK_SET);
 308         if(actual != offset)
 309                 return -errno;
 310         return 0;
 311 }
 312
 313 static int fault_buffer(void *start, int len,
 314                         int (*copy_proc)(void *addr, void *buf, int len))
 315 {
 316         int page = getpagesize(), i;
 317         char c;
 318
 319         for(i = 0; i < len; i += page){
 320                 if((*copy_proc)(start + i, &c, sizeof(c)))
 321                         return -EFAULT;
 322         }
 323         if((len % page) != 0){
 324                 if((*copy_proc)(start + len - 1, &c, sizeof(c)))
 325                         return -EFAULT;
 326         }
 327         return 0;
 328 }
 329
 330 static int file_io(int fd, void *buf, int len,
 331                    int (*io_proc)(int fd, void *buf, int len),
 332                    int (*copy_user_proc)(void *addr, void *buf, int len))
 333 {
 334         int n, err;
 335
 336         do {
 337                 n = (*io_proc)(fd, buf, len);
 338                 if((n < 0) && (errno == EFAULT)){
 339                         err = fault_buffer(buf, len, copy_user_proc);
 340                         if(err)
 341                                 return err;
 342                         n = (*io_proc)(fd, buf, len);
 343                 }
 344         } while((n < 0) && (errno == EINTR));
 345
 346         if(n < 0)
 347                 return -errno;
 348         return n;
 349 }
 350
 351 int os_read_file(int fd, void *buf, int len)
 352 {
 353         return file_io(fd, buf, len, (int (*)(int, void *, int)) read,
 354                        copy_from_user_proc);
 355 }
 356
 357 int os_write_file(int fd, const void *buf, int len)
 358 {
 359         return file_io(fd, (void *) buf, len,
 360                        (int (*)(int, void *, int)) write, copy_to_user_proc);
 361 }
 362
 363 int os_file_size(char *file, unsigned long long *size_out)
 364 {
 365         struct uml_stat buf;
 366         int err;
 367
 368         err = os_stat_file(file, &buf);
 369         if(err < 0){
 370                 printk("Couldn't stat \"%s\" : err = %d\n", file, -err);
 371                 return(err);
 372         }
 373
 374         if(S_ISBLK(buf.ust_mode)){
 375                 int fd, blocks;
 376
 377                 fd = os_open_file(file, of_read(OPENFLAGS()), 0);
 378                 if(fd < 0){
 379                         printk("Couldn't open \"%s\", errno = %d\n", file, -fd);
 380                         return(fd);
 381                 }
 382                 if(ioctl(fd, BLKGETSIZE, &blocks) < 0){
 383                         err = -errno;
 384                         printk("Couldn't get the block size of \"%s\", "
 385                                "errno = %d\n", file, errno);
 386                         os_close_file(fd);
 387                         return(err);
 388                 }
 389                 *size_out = ((long long) blocks) * 512;
 390                 os_close_file(fd);
 391                 return(0);
 392         }
 393         *size_out = buf.ust_size;
 394         return(0);
 395 }
 396
 397 int os_file_modtime(char *file, unsigned long *modtime)
 398 {
 399         struct uml_stat buf;
 400         int err;
 401
 402         err = os_stat_file(file, &buf);
 403         if(err < 0){
 404                 printk("Couldn't stat \"%s\" : err = %d\n", file, -err);
 405                 return err;
 406         }
 407
 408         *modtime = buf.ust_mtime;
 409         return 0;
 410 }
 411
 412 int os_get_exec_close(int fd, int* close_on_exec)
 413 {
 414         int ret;
 415
 416         do {
 417                 ret = fcntl(fd, F_GETFD);
 418         } while((ret < 0) && (errno == EINTR)) ;
 419
 420         if(ret < 0)
 421                 return(-errno);
 422
 423         *close_on_exec = (ret&FD_CLOEXEC) ? 1 : 0;
 424         return(ret);
 425 }
 426
 427 int os_set_exec_close(int fd, int close_on_exec)
 428 {
 429         int flag, err;
 430
 431         if(close_on_exec) flag = FD_CLOEXEC;
 432         else flag = 0;
 433
 434         do {
 435                 err = fcntl(fd, F_SETFD, flag);
 436         } while((err < 0) && (errno == EINTR)) ;
 437
 438         if(err < 0)
 439                 return(-errno);
 440         return(err);
 441 }
 442
 443 int os_pipe(int *fds, int stream, int close_on_exec)
 444 {
 445         int err, type = stream ? SOCK_STREAM : SOCK_DGRAM;
 446
 447         err = socketpair(AF_UNIX, type, 0, fds);
 448         if(err < 0)
 449                 return(-errno);
 450
 451         if(!close_on_exec)
 452                 return(0);
 453
 454         err = os_set_exec_close(fds[0], 1);
 455         if(err < 0)
 456                 goto error;
 457
 458         err = os_set_exec_close(fds[1], 1);
 459         if(err < 0)
 460                 goto error;
 461
 462         return 0;
 463
 464  error:
 465         printk("os_pipe : Setting FD_CLOEXEC failed, err = %d\n", -err);
 466         os_close_file(fds[1]);
 467         os_close_file(fds[0]);
 468         return(err);
 469 }
 470
 471 int os_set_fd_async(int fd, int owner)
 472 {
 473         int err;
 474
 475         /* XXX This should do F_GETFL first */
 476         if(fcntl(fd, F_SETFL, O_ASYNC | O_NONBLOCK) < 0){
 477                 err = -errno;
 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 err;
 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                 err = -errno;
 492                 printk("os_set_fd_async : Failed to fcntl F_SETOWN "
 493                        "(or F_SETSIG) fd %d to pid %d, errno = %d\n", fd,
 494                        owner, errno);
 495                 return err;
 496         }
 497
 498         return 0;
 499 }
 500
 501 int os_clear_fd_async(int fd)
 502 {
 503         int flags = fcntl(fd, F_GETFL);
 504
 505         flags &= ~(O_ASYNC | O_NONBLOCK);
 506         if(fcntl(fd, F_SETFL, flags) < 0)
 507                 return -errno;
 508         return 0;
 509 }
 510
 511 int os_set_fd_block(int fd, int blocking)
 512 {
 513         int flags;
 514
 515         flags = fcntl(fd, F_GETFL);
 516
 517         if(blocking) flags &= ~O_NONBLOCK;
 518         else flags |= O_NONBLOCK;
 519
 520         if(fcntl(fd, F_SETFL, flags) < 0)
 521                 return -errno;
 522
 523         return 0;
 524 }
 525
 526 int os_accept_connection(int fd)
 527 {
 528         int new;
 529
 530         new = accept(fd, NULL, 0);
 531         if(new < 0)
 532                 return -errno;
 533         return new;
 534 }
 535
 536 #ifndef SHUT_RD
 537 #define SHUT_RD 0
 538 #endif
 539
 540 #ifndef SHUT_WR
 541 #define SHUT_WR 1
 542 #endif
 543
 544 #ifndef SHUT_RDWR
 545 #define SHUT_RDWR 2
 546 #endif
 547
 548 int os_shutdown_socket(int fd, int r, int w)
 549 {
 550         int what, err;
 551
 552         if(r && w) what = SHUT_RDWR;
 553         else if(r) what = SHUT_RD;
 554         else if(w) what = SHUT_WR;
 555         else {
 556                 printk("os_shutdown_socket : neither r or w was set\n");
 557                 return -EINVAL;
 558         }
 559         err = shutdown(fd, what);
 560         if(err < 0)
 561                 return -errno;
 562         return 0;
 563 }
 564
 565 int os_rcv_fd(int fd, int *helper_pid_out)
 566 {
 567         int new, n;
 568         char buf[CMSG_SPACE(sizeof(new))];
 569         struct msghdr msg;
 570         struct cmsghdr *cmsg;
 571         struct iovec iov;
 572
 573         msg.msg_name = NULL;
 574         msg.msg_namelen = 0;
 575         iov = ((struct iovec) { .iov_base  = helper_pid_out,
 576                                 .iov_len   = sizeof(*helper_pid_out) });
 577         msg.msg_iov = &iov;
 578         msg.msg_iovlen = 1;
 579         msg.msg_control = buf;
 580         msg.msg_controllen = sizeof(buf);
 581         msg.msg_flags = 0;
 582
 583         n = recvmsg(fd, &msg, 0);
 584         if(n < 0)
 585                 return -errno;
 586
 587         else if(n != sizeof(iov.iov_len))
 588                 *helper_pid_out = -1;
 589
 590         cmsg = CMSG_FIRSTHDR(&msg);
 591         if(cmsg == NULL){
 592                 printk("rcv_fd didn't receive anything, error = %d\n", errno);
 593                 return -1;
 594         }
 595         if((cmsg->cmsg_level != SOL_SOCKET) ||
 596            (cmsg->cmsg_type != SCM_RIGHTS)){
 597                 printk("rcv_fd didn't receive a descriptor\n");
 598                 return -1;
 599         }
 600
 601         new = ((int *) CMSG_DATA(cmsg))[0];
 602         return new;
 603 }
 604
 605 int os_create_unix_socket(char *file, int len, int close_on_exec)
 606 {
 607         struct sockaddr_un addr;
 608         int sock, err;
 609
 610         sock = socket(PF_UNIX, SOCK_DGRAM, 0);
 611         if(sock < 0)
 612                 return -errno;
 613
 614         if(close_on_exec) {
 615                 err = os_set_exec_close(sock, 1);
 616                 if(err < 0)
 617                         printk("create_unix_socket : close_on_exec failed, "
 618                        "err = %d", -err);
 619         }
 620
 621         addr.sun_family = AF_UNIX;
 622
 623         /* XXX Be more careful about overflow */
 624         snprintf(addr.sun_path, len, "%s", file);
 625
 626         err = bind(sock, (struct sockaddr *) &addr, sizeof(addr));
 627         if(err < 0)
 628                 return -errno;
 629
 630         return sock;
 631 }
 632
 633 void os_flush_stdout(void)
 634 {
 635         fflush(stdout);
 636 }
 637
 638 int os_lock_file(int fd, int excl)
 639 {
 640         int type = excl ? F_WRLCK : F_RDLCK;
 641         struct flock lock = ((struct flock) { .l_type   = type,
 642                                               .l_whence = SEEK_SET,
 643                                               .l_start  = 0,
 644                                               .l_len    = 0 } );
 645         int err, save;
 646
 647         err = fcntl(fd, F_SETLK, &lock);
 648         if(!err)
 649                 goto out;
 650
 651         save = -errno;
 652         err = fcntl(fd, F_GETLK, &lock);
 653         if(err){
 654                 err = -errno;
 655                 goto out;
 656         }
 657
 658         printk("F_SETLK failed, file already locked by pid %d\n", lock.l_pid);
 659         err = save;
 660  out:
 661         return err;
 662 }