ish/kernel/fs.c
2017-10-18 15:58:46 -07:00

378 lines
9.9 KiB
C

#include "debug.h"
#include <string.h>
#include <sys/stat.h>
#include "kernel/calls.h"
#include "kernel/errno.h"
#include "kernel/process.h"
#include "kernel/fs.h"
fd_t fd_next() {
for (fd_t fd = 0; fd < MAX_FD; fd++)
if (current->files[fd] == NULL)
return fd;
return -1;
}
struct fd *at_fd(fd_t f) {
if (f == AT_FDCWD_)
return current->pwd;
return current->files[f];
}
// TODO ENAMETOOLONG
dword_t sys_access(addr_t path_addr, dword_t mode) {
char path[MAX_PATH];
if (user_read_string(path_addr, path, sizeof(path)))
return _EFAULT;
return generic_access(path, mode);
}
fd_t sys_openat(fd_t at_f, addr_t path_addr, dword_t flags, dword_t mode) {
char path[MAX_PATH];
if (user_read_string(path_addr, path, sizeof(path)))
return _EFAULT;
STRACE("openat(%d, \"%s\", 0x%x, 0x%x)", at_f, path, flags, mode);
if (flags & O_CREAT_)
mode &= ~current->umask;
fd_t fd_no = fd_next();
if (fd_no == -1)
return _EMFILE;
struct fd *at = at_fd(at_f);
if (at == NULL)
return _EBADF;
struct fd *fd = generic_openat(at, path, flags, mode);
if (IS_ERR(fd))
return PTR_ERR(fd);
current->files[fd_no] = fd;
return fd_no;
}
fd_t sys_open(addr_t path_addr, dword_t flags, dword_t mode) {
return sys_openat(AT_FDCWD_, path_addr, flags, mode);
}
dword_t sys_readlink(addr_t path_addr, addr_t buf_addr, dword_t bufsize) {
char path[MAX_PATH];
if (user_read_string(path_addr, path, sizeof(path)))
return _EFAULT;
char buf[bufsize];
int err = generic_readlink(path, buf, bufsize);
if (err >= 0)
if (user_write_string(buf_addr, buf))
return _EFAULT;
return err;
}
dword_t sys_unlinkat(fd_t at_f, addr_t path_addr) {
char path[MAX_PATH];
if (user_read_string(path_addr, path, sizeof(path)))
return _EFAULT;
struct fd *at = at_fd(at_f);
if (at == NULL)
return _EBADF;
return generic_unlinkat(at, path);
}
dword_t sys_unlink(addr_t path_addr) {
return sys_unlinkat(AT_FDCWD_, path_addr);
}
dword_t sys_close(fd_t f) {
STRACE("close(%d)", f);
struct fd *fd = current->files[f];
if (fd == NULL)
return _EBADF;
if (--fd->refcount == 0) {
int err = fd->ops->close(fd);
if (err < 0)
return err;
free(fd);
}
current->files[f] = NULL;
return 0;
}
dword_t sys_read(fd_t fd_no, addr_t buf_addr, dword_t size) {
char buf[size+1];
struct fd *fd = current->files[fd_no];
if (fd == NULL)
return _EBADF;
int res = fd->ops->read(fd, buf, size);
buf[size] = 0; // null termination for nice debug output
STRACE("read(%d, \"%s\", %d)", fd_no, buf, size);
if (res >= 0)
if (user_write(buf_addr, buf, res))
return _EFAULT;
return res;
}
dword_t sys_readv(fd_t fd_no, addr_t iovec_addr, dword_t iovec_count) {
struct io_vec iovecs[iovec_count];
if (user_get(iovec_addr, iovecs))
return _EFAULT;
int res;
dword_t count = 0;
for (unsigned i = 0; i < iovec_count; i++) {
res = sys_read(fd_no, iovecs[i].base, iovecs[i].len);
if (iovecs[i].len != 0 && res == 0)
break;
if (res < 0)
return res;
count += res;
}
return count;
}
dword_t sys_write(fd_t fd_no, addr_t buf_addr, dword_t size) {
char buf[size+1];
if (user_read(buf_addr, buf, size))
return _EFAULT;
buf[size] = 0; // null termination for nice debug output
STRACE("write(%d, \"%s\", %d)", fd_no, buf, size);
struct fd *fd = current->files[fd_no];
if (fd == NULL)
return _EBADF;
return fd->ops->write(fd, buf, size);
}
dword_t sys_writev(fd_t fd_no, addr_t iovec_addr, dword_t iovec_count) {
struct io_vec iovecs[iovec_count];
if (user_get(iovec_addr, iovecs))
return _EFAULT;
int res;
dword_t count = 0;
for (unsigned i = 0; i < iovec_count; i++) {
res = sys_write(fd_no, iovecs[i].base, iovecs[i].len);
if (res < 0)
return res;
count += res;
}
return count;
}
// TODO doesn't work very well if off_t isn't 64 bits
dword_t sys__llseek(fd_t f, dword_t off_high, dword_t off_low, addr_t res_addr, dword_t whence) {
struct fd *fd = current->files[f];
if (fd == NULL)
return _EBADF;
off_t off = ((off_t) off_high << 32) | off_low;
off_t res = fd->ops->lseek(fd, off, whence);
if (res < 0)
return res;
if (user_put(res_addr, res))
return _EFAULT;
return 0;
}
dword_t sys_lseek(fd_t f, dword_t off, dword_t whence) {
struct fd *fd = current->files[f];
if (fd == NULL)
return _EBADF;
off_t res = fd->ops->lseek(fd, off, whence);
if ((dword_t) res != res)
return _EOVERFLOW;
return res;
}
dword_t sys_ioctl(fd_t f, dword_t cmd, dword_t arg) {
STRACE("ioctl(%d, 0x%x, 0x%x)", f, cmd, arg);
struct fd *fd = current->files[f];
if (fd == NULL)
return _EBADF;
ssize_t size = fd->ops->ioctl_size(fd, cmd);
if (size < 0) {
println("unknown ioctl %x", cmd);
return _EINVAL;
}
if (size == 0)
return fd->ops->ioctl(fd, cmd, (void *) (long) arg);
// praying that this won't break
char buf[size];
if (user_read(arg, buf, size))
return _EFAULT;
int res = fd->ops->ioctl(fd, cmd, buf);
if (res < 0)
return res;
if (user_write(arg, buf, size))
return _EFAULT;
return res;
}
#define F_DUPFD_ 0
#define F_GETFD_ 1
#define F_SETFD_ 2
#define F_GETFL_ 3
#define F_SETFL_ 4
dword_t sys_fcntl64(fd_t f, dword_t cmd, dword_t arg) {
struct fd *fd = current->files[f];
if (fd == NULL)
return _EBADF;
switch (cmd) {
case F_DUPFD_: {
STRACE("fcntl(%d, F_DUPFD, %d)", f, arg);
fd_t new_fd;
for (new_fd = arg; new_fd < MAX_FD; new_fd++)
if (current->files[new_fd] == NULL)
break;
if (new_fd == MAX_FD)
return _EMFILE;
current->files[new_fd] = current->files[f];
current->files[new_fd]->refcount++;
return new_fd;
}
case F_GETFD_:
STRACE("fcntl(%d, F_GETFD)", f);
return fd->flags;
case F_SETFD_:
STRACE("fcntl(%d, F_SETFD, 0x%x)", f, arg);
fd->flags = arg;
return 0;
default:
return _EINVAL;
}
}
dword_t sys_dup(fd_t fd) {
if (current->files[fd] == NULL)
return _EBADF;
fd_t new_fd = fd_next();
if (new_fd < 0)
return _EMFILE;
current->files[new_fd] = current->files[fd];
current->files[new_fd]->refcount++;
return new_fd;
}
dword_t sys_dup2(fd_t fd, fd_t new_fd) {
int res;
if (fd == new_fd)
return fd;
if (current->files[fd] == NULL)
return _EBADF;
if (new_fd >= MAX_FD)
return _EBADF;
if (current->files[new_fd] != NULL) {
res = sys_close(new_fd);
if (res < 0)
return res;
}
current->files[new_fd] = current->files[fd];
current->files[new_fd]->refcount++;
return new_fd;
}
dword_t sys_getcwd(addr_t buf_addr, dword_t size) {
char pwd[MAX_PATH];
int err = current->pwd->ops->getpath(current->pwd, pwd);
if (err < 0)
return err;
if (strlen(pwd) + 1 > size)
return _ERANGE;
char buf[size];
strcpy(buf, pwd);
if (user_write(buf_addr, buf, sizeof(buf)))
return _EFAULT;
return size;
}
dword_t sys_chdir(addr_t path_addr) {
char path[MAX_PATH];
if (user_read_string(path_addr, path, sizeof(path)))
return _EFAULT;
// TODO only normalize the path once
struct statbuf stat;
int err = generic_statat(NULL, path, &stat, true);
if (err < 0)
return err;
if (!(stat.mode & S_IFDIR))
return _ENOTDIR;
struct fd *dir = generic_open(path, O_RDONLY_, 0);
if (IS_ERR(dir))
return PTR_ERR(dir);
current->pwd = dir;
return 0;
}
dword_t sys_umask(dword_t mask) {
mode_t_ old_umask = current->umask;
current->umask = ((mode_t_) mask) & 0777;
return old_umask;
}
static dword_t statfs_mount(struct mount *mount, addr_t buf_addr) {
struct statfsbuf stat;
int err = mount->fs->statfs(mount, &stat);
if (err >= 0)
if (user_put(buf_addr, stat))
return _EFAULT;
return err;
}
dword_t sys_statfs64(addr_t path_addr, addr_t buf_addr) {
char path[MAX_PATH];
if (user_read_string(path_addr, path, sizeof(path)))
return _EFAULT;
return statfs_mount(find_mount(path), buf_addr);
}
dword_t sys_fstatfs64(fd_t f, addr_t buf_addr) {
return statfs_mount(current->files[f]->mount, buf_addr);
}
dword_t sys_flock(fd_t f, dword_t operation) {
struct fd *fd = current->files[f];
if (fd == NULL)
return _EBADF;
return fd->mount->fs->flock(fd, operation);
}
dword_t sys_utimensat(fd_t at_f, addr_t path_addr, addr_t times_addr, dword_t flags) {
struct timespec_ times[2];
if (user_get(times_addr, times))
return _EFAULT;
char path[MAX_PATH];
if (user_read_string(path_addr, path, sizeof(path)))
return _EFAULT;
return 0; // TODO implement
}
dword_t sys_fchmod(fd_t f, dword_t mode) {
struct fd *fd = current->files[f];
if (fd == NULL)
return _EBADF;
mode &= ~S_IFMT;
return fd->mount->fs->fchmod(fd, mode);
}
dword_t sys_fchown32(fd_t f, dword_t owner, dword_t group) {
struct fd *fd = current->files[f];
if (fd == NULL)
return _EBADF;
return fd->mount->fs->fchown(fd, owner, group);
}
// a few stubs
dword_t sys_sendfile(fd_t out_fd, fd_t in_fd, addr_t offset_addr, dword_t count) {
return _EINVAL;
}
dword_t sys_sendfile64(fd_t out_fd, fd_t in_fd, addr_t offset_addr, dword_t count) {
return _EINVAL;
}
dword_t sys_mount(addr_t source_addr, addr_t target_addr, addr_t type_addr, dword_t flags, addr_t data_addr) {
return _EINVAL; // I'm sorry, we do not support this action at this time.
}
struct mount *mounts;