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- /* Copyright (C) 2014 Stony Brook University
- This file is part of Graphene Library OS.
- Graphene Library OS is free software: you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public License
- as published by the Free Software Foundation, either version 3 of the
- License, or (at your option) any later version.
- Graphene Library OS is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU Lesser General Public License for more details.
- You should have received a copy of the GNU Lesser General Public License
- along with this program. If not, see <http://www.gnu.org/licenses/>. */
- /*
- * shim_stat.c
- *
- * Implementation of system call "stat", "lstat", "fstat" and "readlink".
- */
- #include <errno.h>
- #include <linux/fcntl.h>
- #include <pal.h>
- #include <pal_error.h>
- #include <shim_fs.h>
- #include <shim_handle.h>
- #include <shim_internal.h>
- #include <shim_profile.h>
- #include <shim_table.h>
- #include <shim_thread.h>
- int shim_do_stat(const char* file, struct stat* stat) {
- if (!file || test_user_string(file))
- return -EFAULT;
- if (!stat || test_user_memory(stat, sizeof(*stat), true))
- return -EFAULT;
- int ret;
- struct shim_dentry* dent = NULL;
- if ((ret = path_lookupat(NULL, file, LOOKUP_ACCESS | LOOKUP_FOLLOW, &dent, NULL)) < 0)
- goto out;
- struct shim_mount* fs = dent->fs;
- if (!fs->d_ops || !fs->d_ops->stat) {
- ret = -EACCES;
- goto out_dentry;
- }
- ret = fs->d_ops->stat(dent, stat);
- out_dentry:
- put_dentry(dent);
- out:
- return ret;
- }
- int shim_do_lstat(const char* file, struct stat* stat) {
- if (!file || test_user_string(file))
- return -EFAULT;
- if (!stat || test_user_memory(stat, sizeof(*stat), true))
- return -EFAULT;
- int ret;
- struct shim_dentry* dent = NULL;
- if ((ret = path_lookupat(NULL, file, LOOKUP_ACCESS, &dent, NULL)) < 0)
- goto out;
- struct shim_mount* fs = dent->fs;
- if (!fs->d_ops || !fs->d_ops->stat) {
- ret = -EACCES;
- goto out_dentry;
- }
- ret = fs->d_ops->stat(dent, stat);
- out_dentry:
- put_dentry(dent);
- out:
- return ret;
- }
- int shim_do_fstat(int fd, struct stat* stat) {
- struct shim_handle* hdl = get_fd_handle(fd, NULL, NULL);
- if (!hdl)
- return -EBADF;
- int ret = -EACCES;
- struct shim_mount* fs = hdl->fs;
- if (!fs || !fs->fs_ops)
- goto out;
- if (!fs->fs_ops->hstat)
- goto out;
- ret = fs->fs_ops->hstat(hdl, stat);
- out:
- put_handle(hdl);
- return ret;
- }
- int shim_do_readlink(const char* file, char* buf, size_t bufsize) {
- if (!file || test_user_string(file))
- return -EFAULT;
- if (!buf || !bufsize || test_user_memory(buf, bufsize, true))
- return -EFAULT;
- if (bufsize <= 0)
- return -EINVAL;
- int ret;
- struct shim_dentry* dent = NULL;
- struct shim_qstr qstr = QSTR_INIT;
- if ((ret = path_lookupat(NULL, file, LOOKUP_ACCESS, &dent, NULL)) < 0)
- return ret;
- ret = -EINVAL;
- /* The correct behavior is to return -EINVAL if file is not a
- symbolic link */
- if (!(dent->state & DENTRY_ISLINK))
- goto out;
- if (!dent->fs || !dent->fs->d_ops || !dent->fs->d_ops->follow_link)
- goto out;
- ret = dent->fs->d_ops->follow_link(dent, &qstr);
- if (ret < 0)
- goto out;
- ret = -ENAMETOOLONG;
- if (qstr.len >= bufsize)
- goto out;
- memcpy(buf, qstrgetstr(&qstr), qstr.len);
- ret = qstr.len;
- out:
- put_dentry(dent);
- return ret;
- }
- static int __do_statfs(struct shim_mount* fs, struct statfs* buf) {
- __UNUSED(fs);
- if (!buf || test_user_memory(buf, sizeof(*buf), true))
- return -EFAULT;
- memset(buf, 0, sizeof(*buf));
- buf->f_bsize = 4096;
- buf->f_blocks = 20000000;
- buf->f_bfree = 10000000;
- buf->f_bavail = 10000000;
- debug("statfs: %ld %ld %ld\n", buf->f_blocks, buf->f_bfree, buf->f_bavail);
- return 0;
- }
- int shim_do_statfs(const char* path, struct statfs* buf) {
- if (!path || test_user_string(path))
- return -EFAULT;
- int ret;
- struct shim_dentry* dent = NULL;
- if ((ret = path_lookupat(NULL, path, LOOKUP_ACCESS | LOOKUP_FOLLOW, &dent, NULL)) < 0)
- return ret;
- struct shim_mount* fs = dent->fs;
- put_dentry(dent);
- return __do_statfs(fs, buf);
- }
- int shim_do_fstatfs(int fd, struct statfs* buf) {
- struct shim_handle* hdl = get_fd_handle(fd, NULL, NULL);
- if (!hdl)
- return -EBADF;
- struct shim_mount* fs = hdl->fs;
- put_handle(hdl);
- return __do_statfs(fs, buf);
- }
- int shim_do_newfstatat(int dirfd, const char* pathname, struct stat* statbuf, int flags) {
- if (flags & ~(AT_EMPTY_PATH | AT_NO_AUTOMOUNT | AT_SYMLINK_NOFOLLOW))
- return -EINVAL;
- if (test_user_string(pathname))
- return -EFAULT;
- if (test_user_memory(statbuf, sizeof(*statbuf), true))
- return -EFAULT;
- int lookup_flags = LOOKUP_ACCESS | LOOKUP_FOLLOW;
- if (flags & AT_SYMLINK_NOFOLLOW)
- lookup_flags &= ~LOOKUP_FOLLOW;
- if (flags & AT_NO_AUTOMOUNT) {
- /* Do nothing as automount isn't supported */
- debug("ignoring AT_NO_AUTOMOUNT.");
- }
- if (!*pathname) {
- if (!(flags & AT_EMPTY_PATH))
- return -ENOENT;
- if (dirfd == AT_FDCWD) {
- struct shim_dentry* cwd = get_cur_thread()->cwd;
- struct shim_d_ops* d_ops = cwd->fs->d_ops;
- if (d_ops && d_ops->stat)
- return d_ops->stat(cwd, statbuf);
- return -EACCES;
- }
- return shim_do_fstat(dirfd, statbuf);
- }
- struct shim_dentry* dir = NULL;
- if (*pathname != '/') {
- int ret = get_dirfd_dentry(dirfd, &dir);
- if (ret < 0)
- return ret;
- }
- struct shim_dentry* dent;
- int ret = path_lookupat(dir, pathname, lookup_flags, &dent, NULL);
- if (ret >= 0) {
- struct shim_d_ops* d_ops = dent->fs->d_ops;
- if (d_ops && d_ops->stat)
- ret = d_ops->stat(dent, statbuf);
- else
- ret = -EACCES;
- put_dentry(dent);
- }
- if (dir)
- put_dentry(dir);
- return ret;
- }
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