Author: ed Date: Thu Aug 6 06:47:28 2015 New Revision: 286359 URL: https://svnweb.freebsd.org/changeset/base/286359
Log: Add file_open(): the underlying system call of openat(). CloudABI purely operates on file descriptor rights (CAP_*). File descriptor access modes (O_ACCMODE) are emulated on top of rights. Instead of accepting the traditional flags argument, file_open() copies in an fdstat_t object that contains the initial rights the descriptor should have, but also file descriptor flags that should persist after opening (APPEND, NONBLOCK, *SYNC). Only flags that don't persist (EXCL, TRUNC, CREAT, DIRECTORY) are passed in as an argument. file_open() first converts the rights, the persistent flags and the non-persistent flags to fflags. It then calls into vn_open(). If successful, it installs the file descriptor with the requested rights, trimming off rights that don't apply to the type of the file that has been opened. Unlike kern_openat(), this function does not support /dev/fd/*. I can't think of a reason why we need to support this for CloudABI. Obtained from: https://github.com/NuxiNL/freebsd Differential Revision: https://reviews.freebsd.org/D3235 Modified: head/sys/compat/cloudabi/cloudabi_fd.c head/sys/compat/cloudabi/cloudabi_file.c head/sys/compat/cloudabi/cloudabi_util.h Modified: head/sys/compat/cloudabi/cloudabi_fd.c ============================================================================== --- head/sys/compat/cloudabi/cloudabi_fd.c Thu Aug 6 01:49:18 2015 (r286358) +++ head/sys/compat/cloudabi/cloudabi_fd.c Thu Aug 6 06:47:28 2015 (r286359) @@ -290,7 +290,7 @@ cloudabi_convert_filetype(const struct f } /* Removes rights that conflict with the file descriptor type. */ -static void +void cloudabi_remove_conflicting_rights(cloudabi_filetype_t filetype, cloudabi_rights_t *base, cloudabi_rights_t *inheriting) { @@ -499,6 +499,25 @@ cloudabi_sys_fd_stat_get(struct thread * return (copyout(&fsb, (void *)uap->buf, sizeof(fsb))); } +/* Converts CloudABI rights to a set of Capsicum capabilities. */ +int +cloudabi_convert_rights(cloudabi_rights_t in, cap_rights_t *out) +{ + + cap_rights_init(out); +#define MAPPING(cloudabi, ...) do { \ + if (in & (cloudabi)) { \ + cap_rights_set(out, ##__VA_ARGS__); \ + in &= ~(cloudabi); \ + } \ +} while (0); + RIGHTS_MAPPINGS +#undef MAPPING + if (in != 0) + return (ENOTCAPABLE); + return (0); +} + int cloudabi_sys_fd_stat_put(struct thread *td, struct cloudabi_sys_fd_stat_put_args *uap) Modified: head/sys/compat/cloudabi/cloudabi_file.c ============================================================================== --- head/sys/compat/cloudabi/cloudabi_file.c Thu Aug 6 01:49:18 2015 (r286358) +++ head/sys/compat/cloudabi/cloudabi_file.c Thu Aug 6 06:47:28 2015 (r286359) @@ -197,9 +197,128 @@ int cloudabi_sys_file_open(struct thread *td, struct cloudabi_sys_file_open_args *uap) { + cloudabi_fdstat_t fds; + cap_rights_t rights; + struct filecaps fcaps = {}; + struct nameidata nd; + struct file *fp; + struct vnode *vp; + char *path; + int error, fd, fflags; + bool read, write; + + error = copyin(uap->fds, &fds, sizeof(fds)); + if (error != 0) + return (error); + + /* All the requested rights should be set on the descriptor. */ + error = cloudabi_convert_rights( + fds.fs_rights_base | fds.fs_rights_inheriting, &rights); + if (error != 0) + return (error); + cap_rights_set(&rights, CAP_LOOKUP); - /* Not implemented. */ - return (ENOSYS); + /* Convert rights to corresponding access mode. */ + read = (fds.fs_rights_base & (CLOUDABI_RIGHT_FD_READ | + CLOUDABI_RIGHT_FILE_READDIR | CLOUDABI_RIGHT_MEM_MAP_EXEC)) != 0; + write = (fds.fs_rights_base & (CLOUDABI_RIGHT_FD_DATASYNC | + CLOUDABI_RIGHT_FD_WRITE | CLOUDABI_RIGHT_FILE_ALLOCATE | + CLOUDABI_RIGHT_FILE_STAT_FPUT_SIZE)) != 0; + fflags = read ? write ? FREAD | FWRITE : FREAD : FWRITE; + + /* Convert open flags. */ + if ((uap->oflags & CLOUDABI_O_CREAT) != 0) { + fflags |= O_CREAT; + cap_rights_set(&rights, CAP_CREATE); + } + if ((uap->oflags & CLOUDABI_O_DIRECTORY) != 0) + fflags |= O_DIRECTORY; + if ((uap->oflags & CLOUDABI_O_EXCL) != 0) + fflags |= O_EXCL; + if ((uap->oflags & CLOUDABI_O_TRUNC) != 0) { + fflags |= O_TRUNC; + cap_rights_set(&rights, CAP_FTRUNCATE); + } + if ((fds.fs_flags & CLOUDABI_FDFLAG_APPEND) != 0) + fflags |= O_APPEND; + if ((fds.fs_flags & CLOUDABI_FDFLAG_NONBLOCK) != 0) + fflags |= O_NONBLOCK; + if ((fds.fs_flags & (CLOUDABI_FDFLAG_SYNC | CLOUDABI_FDFLAG_DSYNC | + CLOUDABI_FDFLAG_RSYNC)) != 0) { + fflags |= O_SYNC; + cap_rights_set(&rights, CAP_FSYNC); + } + if ((uap->fd & CLOUDABI_LOOKUP_SYMLINK_FOLLOW) == 0) + fflags |= O_NOFOLLOW; + if (write && (fflags & (O_APPEND | O_TRUNC)) == 0) + cap_rights_set(&rights, CAP_SEEK); + + /* Allocate new file descriptor. */ + error = falloc_noinstall(td, &fp); + if (error != 0) + return (error); + fp->f_flag = fflags & FMASK; + + /* Open path. */ + error = copyin_path(uap->path, uap->pathlen, &path); + if (error != 0) { + fdrop(fp, td); + return (error); + } + NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, path, uap->fd, + &rights, td); + error = vn_open(&nd, &fflags, 0777 & ~td->td_proc->p_fd->fd_cmask, fp); + cloudabi_freestr(path); + if (error != 0) { + /* Custom operations provided. */ + if (error == ENXIO && fp->f_ops != &badfileops) + goto success; + + /* + * POSIX compliance: return ELOOP in case openat() is + * called on a symbolic link and O_NOFOLLOW is set. + */ + if (error == EMLINK) + error = ELOOP; + fdrop(fp, td); + return (error); + } + NDFREE(&nd, NDF_ONLY_PNBUF); + filecaps_free(&nd.ni_filecaps); + fp->f_vnode = vp = nd.ni_vp; + + /* Install vnode operations if no custom operations are provided. */ + if (fp->f_ops == &badfileops) { + fp->f_seqcount = 1; + finit(fp, (fflags & FMASK) | (fp->f_flag & FHASLOCK), + DTYPE_VNODE, vp, &vnops); + } + VOP_UNLOCK(vp, 0); + + /* Truncate file. */ + if (fflags & O_TRUNC) { + error = fo_truncate(fp, 0, td->td_ucred, td); + if (error != 0) { + fdrop(fp, td); + return (error); + } + } + +success: + /* Determine which Capsicum rights to set on the file descriptor. */ + cloudabi_remove_conflicting_rights(cloudabi_convert_filetype(fp), + &fds.fs_rights_base, &fds.fs_rights_inheriting); + cloudabi_convert_rights(fds.fs_rights_base | fds.fs_rights_inheriting, + &fcaps.fc_rights); + if (cap_rights_is_set(&fcaps.fc_rights)) + fcaps.fc_fcntls = CAP_FCNTL_SETFL; + + error = finstall(td, fp, &fd, fflags, &fcaps); + fdrop(fp, td); + if (error != 0) + return (error); + td->td_retval[0] = fd; + return (0); } /* Converts a FreeBSD directory entry structure and writes it to userspace. */ Modified: head/sys/compat/cloudabi/cloudabi_util.h ============================================================================== --- head/sys/compat/cloudabi/cloudabi_util.h Thu Aug 6 01:49:18 2015 (r286358) +++ head/sys/compat/cloudabi/cloudabi_util.h Thu Aug 6 06:47:28 2015 (r286359) @@ -50,6 +50,13 @@ void cloudabi_convert_sockaddr(const str /* Converts a file descriptor to a CloudABI file descriptor type. */ cloudabi_filetype_t cloudabi_convert_filetype(const struct file *); +/* Converts CloudABI rights to a set of Capsicum capabilities. */ +int cloudabi_convert_rights(cloudabi_rights_t, cap_rights_t *); + +/* Removes rights that conflict with the file descriptor type. */ +void cloudabi_remove_conflicting_rights(cloudabi_filetype_t, + cloudabi_rights_t *, cloudabi_rights_t *); + /* Converts a struct timespec to a CloudABI timestamp. */ int cloudabi_convert_timespec(const struct timespec *, cloudabi_timestamp_t *); _______________________________________________ svn-src-head@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
