sys/compat/cloudabi/cloudabi_fd.c

   1 /*-
   2  * Copyright (c) 2015 Nuxi, https://nuxi.nl/
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  23  * SUCH DAMAGE.
  24  */
  25
  26 #include <sys/cdefs.h>
  27 __FBSDID("$FreeBSD$");
  28
  29 #include <sys/param.h>
  30 #include <sys/capsicum.h>
  31 #include <sys/filedesc.h>
  32 #include <sys/proc.h>
  33 #include <sys/mman.h>
  34 #include <sys/socketvar.h>
  35 #include <sys/syscallsubr.h>
  36 #include <sys/sysproto.h>
  37 #include <sys/systm.h>
  38 #include <sys/unistd.h>
  39 #include <sys/vnode.h>
  40
  41 #include <contrib/cloudabi/cloudabi_types_common.h>
  42
  43 #include <compat/cloudabi/cloudabi_proto.h>
  44 #include <compat/cloudabi/cloudabi_util.h>
  45
  46 /* Translation between CloudABI and Capsicum rights. */
  47 #define RIGHTS_MAPPINGS \
  48         MAPPING(CLOUDABI_RIGHT_FD_DATASYNC, CAP_FSYNC)                  \
  49         MAPPING(CLOUDABI_RIGHT_FD_READ, CAP_READ)                       \
  50         MAPPING(CLOUDABI_RIGHT_FD_SEEK, CAP_SEEK)                       \
  51         MAPPING(CLOUDABI_RIGHT_FD_STAT_PUT_FLAGS, CAP_FCNTL)            \
  52         MAPPING(CLOUDABI_RIGHT_FD_SYNC, CAP_FSYNC)                      \
  53         MAPPING(CLOUDABI_RIGHT_FD_TELL, CAP_SEEK_TELL)                  \
  54         MAPPING(CLOUDABI_RIGHT_FD_WRITE, CAP_WRITE)                     \
  55         MAPPING(CLOUDABI_RIGHT_FILE_ADVISE)                             \
  56         MAPPING(CLOUDABI_RIGHT_FILE_ALLOCATE, CAP_WRITE)                \
  57         MAPPING(CLOUDABI_RIGHT_FILE_CREATE_DIRECTORY, CAP_MKDIRAT)      \
  58         MAPPING(CLOUDABI_RIGHT_FILE_CREATE_FILE, CAP_CREATE)            \
  59         MAPPING(CLOUDABI_RIGHT_FILE_LINK_SOURCE, CAP_LINKAT_SOURCE)     \
  60         MAPPING(CLOUDABI_RIGHT_FILE_LINK_TARGET, CAP_LINKAT_TARGET)     \
  61         MAPPING(CLOUDABI_RIGHT_FILE_OPEN, CAP_LOOKUP)                   \
  62         MAPPING(CLOUDABI_RIGHT_FILE_READDIR, CAP_READ)                  \
  63         MAPPING(CLOUDABI_RIGHT_FILE_READLINK, CAP_LOOKUP)               \
  64         MAPPING(CLOUDABI_RIGHT_FILE_RENAME_SOURCE, CAP_RENAMEAT_SOURCE) \
  65         MAPPING(CLOUDABI_RIGHT_FILE_RENAME_TARGET, CAP_RENAMEAT_TARGET) \
  66         MAPPING(CLOUDABI_RIGHT_FILE_STAT_FGET, CAP_FSTAT)               \
  67         MAPPING(CLOUDABI_RIGHT_FILE_STAT_FPUT_SIZE, CAP_FTRUNCATE)      \
  68         MAPPING(CLOUDABI_RIGHT_FILE_STAT_FPUT_TIMES, CAP_FUTIMES)       \
  69         MAPPING(CLOUDABI_RIGHT_FILE_STAT_GET, CAP_FSTATAT)              \
  70         MAPPING(CLOUDABI_RIGHT_FILE_STAT_PUT_TIMES, CAP_FUTIMESAT)      \
  71         MAPPING(CLOUDABI_RIGHT_FILE_SYMLINK, CAP_SYMLINKAT)             \
  72         MAPPING(CLOUDABI_RIGHT_FILE_UNLINK, CAP_UNLINKAT)               \
  73         MAPPING(CLOUDABI_RIGHT_MEM_MAP, CAP_MMAP)                       \
  74         MAPPING(CLOUDABI_RIGHT_MEM_MAP_EXEC, CAP_MMAP_X)                \
  75         MAPPING(CLOUDABI_RIGHT_POLL_FD_READWRITE, CAP_EVENT)            \
  76         MAPPING(CLOUDABI_RIGHT_POLL_MODIFY, CAP_KQUEUE_CHANGE)          \
  77         MAPPING(CLOUDABI_RIGHT_POLL_PROC_TERMINATE, CAP_EVENT)          \
  78         MAPPING(CLOUDABI_RIGHT_POLL_WAIT, CAP_KQUEUE_EVENT)             \
  79         MAPPING(CLOUDABI_RIGHT_PROC_EXEC, CAP_FEXECVE)                  \
  80         MAPPING(CLOUDABI_RIGHT_SOCK_SHUTDOWN, CAP_SHUTDOWN)             \
  81
  82 int
  83 cloudabi_sys_fd_close(struct thread *td, struct cloudabi_sys_fd_close_args *uap)
  84 {
  85
  86         return (kern_close(td, uap->fd));
  87 }
  88
  89 int
  90 cloudabi_sys_fd_create1(struct thread *td,
  91     struct cloudabi_sys_fd_create1_args *uap)
  92 {
  93         struct filecaps fcaps = {};
  94
  95         switch (uap->type) {
  96         case CLOUDABI_FILETYPE_POLL:
  97                 cap_rights_init(&fcaps.fc_rights, CAP_FSTAT, CAP_KQUEUE);
  98                 return (kern_kqueue(td, 0, &fcaps));
  99         case CLOUDABI_FILETYPE_SHARED_MEMORY:
 100                 cap_rights_init(&fcaps.fc_rights, CAP_FSTAT, CAP_FTRUNCATE,
 101                     CAP_MMAP_RWX);
 102                 return (kern_shm_open(td, SHM_ANON, O_RDWR, 0, &fcaps));
 103         default:
 104                 return (EINVAL);
 105         }
 106 }
 107
 108 int
 109 cloudabi_sys_fd_create2(struct thread *td,
 110     struct cloudabi_sys_fd_create2_args *uap)
 111 {
 112         int fds[2];
 113         int error, type;
 114
 115         switch (uap->type) {
 116         case CLOUDABI_FILETYPE_SOCKET_DGRAM:
 117                 type = SOCK_DGRAM;
 118                 break;
 119         case CLOUDABI_FILETYPE_SOCKET_STREAM:
 120                 type = SOCK_STREAM;
 121                 break;
 122         default:
 123                 return (EINVAL);
 124         }
 125
 126         error = kern_socketpair(td, AF_UNIX, type, 0, fds);
 127         if (error == 0) {
 128                 td->td_retval[0] = fds[0];
 129                 td->td_retval[1] = fds[1];
 130         }
 131         return (0);
 132 }
 133
 134 int
 135 cloudabi_sys_fd_datasync(struct thread *td,
 136     struct cloudabi_sys_fd_datasync_args *uap)
 137 {
 138
 139         return (kern_fsync(td, uap->fd, false));
 140 }
 141
 142 int
 143 cloudabi_sys_fd_dup(struct thread *td, struct cloudabi_sys_fd_dup_args *uap)
 144 {
 145
 146         return (kern_dup(td, FDDUP_NORMAL, 0, uap->from, 0));
 147 }
 148
 149 int
 150 cloudabi_sys_fd_replace(struct thread *td,
 151     struct cloudabi_sys_fd_replace_args *uap)
 152 {
 153         int error;
 154
 155         /*
 156          * CloudABI's equivalent to dup2(). CloudABI processes should
 157          * not depend on hardcoded file descriptor layouts, but simply
 158          * use the file descriptor numbers that are allocated by the
 159          * kernel. Duplicating file descriptors to arbitrary numbers
 160          * should not be done.
 161          *
 162          * Invoke kern_dup() with FDDUP_MUSTREPLACE, so that we return
 163          * EBADF when duplicating to a nonexistent file descriptor. Also
 164          * clear the return value, as this system call yields no return
 165          * value.
 166          */
 167         error = kern_dup(td, FDDUP_MUSTREPLACE, 0, uap->from, uap->to);
 168         td->td_retval[0] = 0;
 169         return (error);
 170 }
 171
 172 int
 173 cloudabi_sys_fd_seek(struct thread *td, struct cloudabi_sys_fd_seek_args *uap)
 174 {
 175         int whence;
 176
 177         switch (uap->whence) {
 178         case CLOUDABI_WHENCE_CUR:
 179                 whence = SEEK_CUR;
 180                 break;
 181         case CLOUDABI_WHENCE_END:
 182                 whence = SEEK_END;
 183                 break;
 184         case CLOUDABI_WHENCE_SET:
 185                 whence = SEEK_SET;
 186                 break;
 187         default:
 188                 return (EINVAL);
 189         }
 190
 191         return (kern_lseek(td, uap->fd, uap->offset, whence));
 192 }
 193
 194 /* Converts a file descriptor to a CloudABI file descriptor type. */
 195 cloudabi_filetype_t
 196 cloudabi_convert_filetype(const struct file *fp)
 197 {
 198         struct socket *so;
 199         struct vnode *vp;
 200
 201         switch (fp->f_type) {
 202         case DTYPE_FIFO:
 203                 return (CLOUDABI_FILETYPE_SOCKET_STREAM);
 204         case DTYPE_KQUEUE:
 205                 return (CLOUDABI_FILETYPE_POLL);
 206         case DTYPE_PIPE:
 207                 return (CLOUDABI_FILETYPE_SOCKET_STREAM);
 208         case DTYPE_PROCDESC:
 209                 return (CLOUDABI_FILETYPE_PROCESS);
 210         case DTYPE_SHM:
 211                 return (CLOUDABI_FILETYPE_SHARED_MEMORY);
 212         case DTYPE_SOCKET:
 213                 so = fp->f_data;
 214                 switch (so->so_type) {
 215                 case SOCK_DGRAM:
 216                         return (CLOUDABI_FILETYPE_SOCKET_DGRAM);
 217                 case SOCK_STREAM:
 218                         return (CLOUDABI_FILETYPE_SOCKET_STREAM);
 219                 default:
 220                         return (CLOUDABI_FILETYPE_UNKNOWN);
 221                 }
 222         case DTYPE_VNODE:
 223                 vp = fp->f_vnode;
 224                 switch (vp->v_type) {
 225                 case VBLK:
 226                         return (CLOUDABI_FILETYPE_BLOCK_DEVICE);
 227                 case VCHR:
 228                         return (CLOUDABI_FILETYPE_CHARACTER_DEVICE);
 229                 case VDIR:
 230                         return (CLOUDABI_FILETYPE_DIRECTORY);
 231                 case VFIFO:
 232                         return (CLOUDABI_FILETYPE_SOCKET_STREAM);
 233                 case VLNK:
 234                         return (CLOUDABI_FILETYPE_SYMBOLIC_LINK);
 235                 case VREG:
 236                         return (CLOUDABI_FILETYPE_REGULAR_FILE);
 237                 case VSOCK:
 238                         return (CLOUDABI_FILETYPE_SOCKET_STREAM);
 239                 default:
 240                         return (CLOUDABI_FILETYPE_UNKNOWN);
 241                 }
 242         default:
 243                 return (CLOUDABI_FILETYPE_UNKNOWN);
 244         }
 245 }
 246
 247 /* Removes rights that conflict with the file descriptor type. */
 248 void
 249 cloudabi_remove_conflicting_rights(cloudabi_filetype_t filetype,
 250     cloudabi_rights_t *base, cloudabi_rights_t *inheriting)
 251 {
 252
 253         /*
 254          * CloudABI has a small number of additional rights bits to
 255          * disambiguate between multiple purposes. Remove the bits that
 256          * don't apply to the type of the file descriptor.
 257          *
 258          * As file descriptor access modes (O_ACCMODE) has been fully
 259          * replaced by rights bits, CloudABI distinguishes between
 260          * rights that apply to the file descriptor itself (base) versus
 261          * rights of new file descriptors derived from them
 262          * (inheriting). The code below approximates the pair by
 263          * decomposing depending on the file descriptor type.
 264          *
 265          * We need to be somewhat accurate about which actions can
 266          * actually be performed on the file descriptor, as functions
 267          * like fcntl(fd, F_GETFL) are emulated on top of this.
 268          */
 269         switch (filetype) {
 270         case CLOUDABI_FILETYPE_DIRECTORY:
 271                 *base &= CLOUDABI_RIGHT_FD_STAT_PUT_FLAGS |
 272                     CLOUDABI_RIGHT_FD_SYNC | CLOUDABI_RIGHT_FILE_ADVISE |
 273                     CLOUDABI_RIGHT_FILE_CREATE_DIRECTORY |
 274                     CLOUDABI_RIGHT_FILE_CREATE_FILE |
 275                     CLOUDABI_RIGHT_FILE_LINK_SOURCE |
 276                     CLOUDABI_RIGHT_FILE_LINK_TARGET |
 277                     CLOUDABI_RIGHT_FILE_OPEN |
 278                     CLOUDABI_RIGHT_FILE_READDIR |
 279                     CLOUDABI_RIGHT_FILE_READLINK |
 280                     CLOUDABI_RIGHT_FILE_RENAME_SOURCE |
 281                     CLOUDABI_RIGHT_FILE_RENAME_TARGET |
 282                     CLOUDABI_RIGHT_FILE_STAT_FGET |
 283                     CLOUDABI_RIGHT_FILE_STAT_FPUT_TIMES |
 284                     CLOUDABI_RIGHT_FILE_STAT_GET |
 285                     CLOUDABI_RIGHT_FILE_STAT_PUT_TIMES |
 286                     CLOUDABI_RIGHT_FILE_SYMLINK |
 287                     CLOUDABI_RIGHT_FILE_UNLINK |
 288                     CLOUDABI_RIGHT_POLL_FD_READWRITE;
 289                 *inheriting &= CLOUDABI_RIGHT_FD_DATASYNC |
 290                     CLOUDABI_RIGHT_FD_READ |
 291                     CLOUDABI_RIGHT_FD_SEEK |
 292                     CLOUDABI_RIGHT_FD_STAT_PUT_FLAGS |
 293                     CLOUDABI_RIGHT_FD_SYNC |
 294                     CLOUDABI_RIGHT_FD_TELL |
 295                     CLOUDABI_RIGHT_FD_WRITE |
 296                     CLOUDABI_RIGHT_FILE_ADVISE |
 297                     CLOUDABI_RIGHT_FILE_ALLOCATE |
 298                     CLOUDABI_RIGHT_FILE_CREATE_DIRECTORY |
 299                     CLOUDABI_RIGHT_FILE_CREATE_FILE |
 300                     CLOUDABI_RIGHT_FILE_LINK_SOURCE |
 301                     CLOUDABI_RIGHT_FILE_LINK_TARGET |
 302                     CLOUDABI_RIGHT_FILE_OPEN |
 303                     CLOUDABI_RIGHT_FILE_READDIR |
 304                     CLOUDABI_RIGHT_FILE_READLINK |
 305                     CLOUDABI_RIGHT_FILE_RENAME_SOURCE |
 306                     CLOUDABI_RIGHT_FILE_RENAME_TARGET |
 307                     CLOUDABI_RIGHT_FILE_STAT_FGET |
 308                     CLOUDABI_RIGHT_FILE_STAT_FPUT_SIZE |
 309                     CLOUDABI_RIGHT_FILE_STAT_FPUT_TIMES |
 310                     CLOUDABI_RIGHT_FILE_STAT_GET |
 311                     CLOUDABI_RIGHT_FILE_STAT_PUT_TIMES |
 312                     CLOUDABI_RIGHT_FILE_SYMLINK |
 313                     CLOUDABI_RIGHT_FILE_UNLINK |
 314                     CLOUDABI_RIGHT_MEM_MAP |
 315                     CLOUDABI_RIGHT_MEM_MAP_EXEC |
 316                     CLOUDABI_RIGHT_POLL_FD_READWRITE |
 317                     CLOUDABI_RIGHT_PROC_EXEC;
 318                 break;
 319         case CLOUDABI_FILETYPE_POLL:
 320                 *base &= ~CLOUDABI_RIGHT_FILE_ADVISE;
 321                 *inheriting = 0;
 322                 break;
 323         case CLOUDABI_FILETYPE_PROCESS:
 324                 *base &= ~(CLOUDABI_RIGHT_FILE_ADVISE |
 325                     CLOUDABI_RIGHT_POLL_FD_READWRITE);
 326                 *inheriting = 0;
 327                 break;
 328         case CLOUDABI_FILETYPE_REGULAR_FILE:
 329                 *base &= CLOUDABI_RIGHT_FD_DATASYNC |
 330                     CLOUDABI_RIGHT_FD_READ |
 331                     CLOUDABI_RIGHT_FD_SEEK |
 332                     CLOUDABI_RIGHT_FD_STAT_PUT_FLAGS |
 333                     CLOUDABI_RIGHT_FD_SYNC |
 334                     CLOUDABI_RIGHT_FD_TELL |
 335                     CLOUDABI_RIGHT_FD_WRITE |
 336                     CLOUDABI_RIGHT_FILE_ADVISE |
 337                     CLOUDABI_RIGHT_FILE_ALLOCATE |
 338                     CLOUDABI_RIGHT_FILE_STAT_FGET |
 339                     CLOUDABI_RIGHT_FILE_STAT_FPUT_SIZE |
 340                     CLOUDABI_RIGHT_FILE_STAT_FPUT_TIMES |
 341                     CLOUDABI_RIGHT_MEM_MAP |
 342                     CLOUDABI_RIGHT_MEM_MAP_EXEC |
 343                     CLOUDABI_RIGHT_POLL_FD_READWRITE |
 344                     CLOUDABI_RIGHT_PROC_EXEC;
 345                 *inheriting = 0;
 346                 break;
 347         case CLOUDABI_FILETYPE_SHARED_MEMORY:
 348                 *base &= ~(CLOUDABI_RIGHT_FD_SEEK |
 349                     CLOUDABI_RIGHT_FD_TELL |
 350                     CLOUDABI_RIGHT_FILE_ADVISE |
 351                     CLOUDABI_RIGHT_FILE_ALLOCATE |
 352                     CLOUDABI_RIGHT_FILE_READDIR);
 353                 *inheriting = 0;
 354                 break;
 355         case CLOUDABI_FILETYPE_SOCKET_DGRAM:
 356         case CLOUDABI_FILETYPE_SOCKET_STREAM:
 357                 *base &= CLOUDABI_RIGHT_FD_READ |
 358                     CLOUDABI_RIGHT_FD_STAT_PUT_FLAGS |
 359                     CLOUDABI_RIGHT_FD_WRITE |
 360                     CLOUDABI_RIGHT_FILE_STAT_FGET |
 361                     CLOUDABI_RIGHT_POLL_FD_READWRITE |
 362                     CLOUDABI_RIGHT_SOCK_SHUTDOWN;
 363                 break;
 364         default:
 365                 *inheriting = 0;
 366                 break;
 367         }
 368 }
 369
 370 /* Converts FreeBSD's Capsicum rights to CloudABI's set of rights. */
 371 static void
 372 convert_capabilities(const cap_rights_t *capabilities,
 373     cloudabi_filetype_t filetype, cloudabi_rights_t *base,
 374     cloudabi_rights_t *inheriting)
 375 {
 376         cloudabi_rights_t rights;
 377
 378         /* Convert FreeBSD bits to CloudABI bits. */
 379         rights = 0;
 380 #define MAPPING(cloudabi, ...) do {                             \
 381         if (cap_rights_is_set(capabilities, ##__VA_ARGS__))     \
 382                 rights |= (cloudabi);                           \
 383 } while (0);
 384         RIGHTS_MAPPINGS
 385 #undef MAPPING
 386
 387         *base = rights;
 388         *inheriting = rights;
 389         cloudabi_remove_conflicting_rights(filetype, base, inheriting);
 390 }
 391
 392 int
 393 cloudabi_sys_fd_stat_get(struct thread *td,
 394     struct cloudabi_sys_fd_stat_get_args *uap)
 395 {
 396         cloudabi_fdstat_t fsb = {};
 397         struct file *fp;
 398         cap_rights_t rights;
 399         struct filecaps fcaps;
 400         int error, oflags;
 401
 402         /* Obtain file descriptor properties. */
 403         error = fget_cap(td, uap->fd, cap_rights_init(&rights), &fp,
 404             &fcaps);
 405         if (error != 0)
 406                 return (error);
 407         oflags = OFLAGS(fp->f_flag);
 408         fsb.fs_filetype = cloudabi_convert_filetype(fp);
 409         fdrop(fp, td);
 410
 411         /* Convert file descriptor flags. */
 412         if (oflags & O_APPEND)
 413                 fsb.fs_flags |= CLOUDABI_FDFLAG_APPEND;
 414         if (oflags & O_NONBLOCK)
 415                 fsb.fs_flags |= CLOUDABI_FDFLAG_NONBLOCK;
 416         if (oflags & O_SYNC)
 417                 fsb.fs_flags |= CLOUDABI_FDFLAG_SYNC;
 418
 419         /* Convert capabilities to CloudABI rights. */
 420         convert_capabilities(&fcaps.fc_rights, fsb.fs_filetype,
 421             &fsb.fs_rights_base, &fsb.fs_rights_inheriting);
 422         filecaps_free(&fcaps);
 423         return (copyout(&fsb, (void *)uap->buf, sizeof(fsb)));
 424 }
 425
 426 /* Converts CloudABI rights to a set of Capsicum capabilities. */
 427 int
 428 cloudabi_convert_rights(cloudabi_rights_t in, cap_rights_t *out)
 429 {
 430
 431         cap_rights_init(out);
 432 #define MAPPING(cloudabi, ...) do {                     \
 433         if (in & (cloudabi)) {                          \
 434                 cap_rights_set(out, ##__VA_ARGS__);     \
 435                 in &= ~(cloudabi);                      \
 436         }                                               \
 437 } while (0);
 438         RIGHTS_MAPPINGS
 439 #undef MAPPING
 440         if (in != 0)
 441                 return (ENOTCAPABLE);
 442         return (0);
 443 }
 444
 445 int
 446 cloudabi_sys_fd_stat_put(struct thread *td,
 447     struct cloudabi_sys_fd_stat_put_args *uap)
 448 {
 449         cloudabi_fdstat_t fsb;
 450         cap_rights_t rights;
 451         int error, oflags;
 452
 453         error = copyin(uap->buf, &fsb, sizeof(fsb));
 454         if (error != 0)
 455                 return (error);
 456
 457         if (uap->flags == CLOUDABI_FDSTAT_FLAGS) {
 458                 /* Convert flags. */
 459                 oflags = 0;
 460                 if (fsb.fs_flags & CLOUDABI_FDFLAG_APPEND)
 461                         oflags |= O_APPEND;
 462                 if (fsb.fs_flags & CLOUDABI_FDFLAG_NONBLOCK)
 463                         oflags |= O_NONBLOCK;
 464                 if (fsb.fs_flags & (CLOUDABI_FDFLAG_SYNC |
 465                     CLOUDABI_FDFLAG_DSYNC | CLOUDABI_FDFLAG_RSYNC))
 466                         oflags |= O_SYNC;
 467                 return (kern_fcntl(td, uap->fd, F_SETFL, oflags));
 468         } else if (uap->flags == CLOUDABI_FDSTAT_RIGHTS) {
 469                 /* Convert rights. */
 470                 error = cloudabi_convert_rights(
 471                     fsb.fs_rights_base | fsb.fs_rights_inheriting, &rights);
 472                 if (error != 0)
 473                         return (error);
 474                 return (kern_cap_rights_limit(td, uap->fd, &rights));
 475         }
 476         return (EINVAL);
 477 }
 478
 479 int
 480 cloudabi_sys_fd_sync(struct thread *td, struct cloudabi_sys_fd_sync_args *uap)
 481 {
 482
 483         return (kern_fsync(td, uap->fd, true));
 484 }