swh:1:snp:49cd9498d6cccc5e78252c27dcb645bcf7bf0c91
Tip revision: 92ed301919932f777713b9172e525674157e983d authored by Linus Torvalds on 26 July 2020, 21:14:06 UTC
Linux 5.8-rc7
Linux 5.8-rc7
Tip revision: 92ed301
file.c
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
*/
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <linux/falloc.h>
#include <sys/ioctl.h>
#include <sys/mount.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/sysmacros.h>
#include <sys/un.h>
#include <sys/types.h>
#include <sys/eventfd.h>
#include <poll.h>
#include <os.h>
static void copy_stat(struct uml_stat *dst, const struct stat64 *src)
{
*dst = ((struct uml_stat) {
.ust_dev = src->st_dev, /* device */
.ust_ino = src->st_ino, /* inode */
.ust_mode = src->st_mode, /* protection */
.ust_nlink = src->st_nlink, /* number of hard links */
.ust_uid = src->st_uid, /* user ID of owner */
.ust_gid = src->st_gid, /* group ID of owner */
.ust_size = src->st_size, /* total size, in bytes */
.ust_blksize = src->st_blksize, /* blocksize for filesys I/O */
.ust_blocks = src->st_blocks, /* number of blocks allocated */
.ust_atime = src->st_atime, /* time of last access */
.ust_mtime = src->st_mtime, /* time of last modification */
.ust_ctime = src->st_ctime, /* time of last change */
});
}
int os_stat_fd(const int fd, struct uml_stat *ubuf)
{
struct stat64 sbuf;
int err;
CATCH_EINTR(err = fstat64(fd, &sbuf));
if (err < 0)
return -errno;
if (ubuf != NULL)
copy_stat(ubuf, &sbuf);
return err;
}
int os_stat_file(const char *file_name, struct uml_stat *ubuf)
{
struct stat64 sbuf;
int err;
CATCH_EINTR(err = stat64(file_name, &sbuf));
if (err < 0)
return -errno;
if (ubuf != NULL)
copy_stat(ubuf, &sbuf);
return err;
}
int os_access(const char *file, int mode)
{
int amode, err;
amode = (mode & OS_ACC_R_OK ? R_OK : 0) |
(mode & OS_ACC_W_OK ? W_OK : 0) |
(mode & OS_ACC_X_OK ? X_OK : 0) |
(mode & OS_ACC_F_OK ? F_OK : 0);
err = access(file, amode);
if (err < 0)
return -errno;
return 0;
}
/* FIXME? required only by hostaudio (because it passes ioctls verbatim) */
int os_ioctl_generic(int fd, unsigned int cmd, unsigned long arg)
{
int err;
err = ioctl(fd, cmd, arg);
if (err < 0)
return -errno;
return err;
}
/* FIXME: ensure namebuf in os_get_if_name is big enough */
int os_get_ifname(int fd, char* namebuf)
{
if (ioctl(fd, SIOCGIFNAME, namebuf) < 0)
return -errno;
return 0;
}
int os_set_slip(int fd)
{
int disc, sencap;
disc = N_SLIP;
if (ioctl(fd, TIOCSETD, &disc) < 0)
return -errno;
sencap = 0;
if (ioctl(fd, SIOCSIFENCAP, &sencap) < 0)
return -errno;
return 0;
}
int os_mode_fd(int fd, int mode)
{
int err;
CATCH_EINTR(err = fchmod(fd, mode));
if (err < 0)
return -errno;
return 0;
}
int os_file_type(char *file)
{
struct uml_stat buf;
int err;
err = os_stat_file(file, &buf);
if (err < 0)
return err;
if (S_ISDIR(buf.ust_mode))
return OS_TYPE_DIR;
else if (S_ISLNK(buf.ust_mode))
return OS_TYPE_SYMLINK;
else if (S_ISCHR(buf.ust_mode))
return OS_TYPE_CHARDEV;
else if (S_ISBLK(buf.ust_mode))
return OS_TYPE_BLOCKDEV;
else if (S_ISFIFO(buf.ust_mode))
return OS_TYPE_FIFO;
else if (S_ISSOCK(buf.ust_mode))
return OS_TYPE_SOCK;
else return OS_TYPE_FILE;
}
int os_file_mode(const char *file, struct openflags *mode_out)
{
int err;
*mode_out = OPENFLAGS();
err = access(file, W_OK);
if (err && (errno != EACCES))
return -errno;
else if (!err)
*mode_out = of_write(*mode_out);
err = access(file, R_OK);
if (err && (errno != EACCES))
return -errno;
else if (!err)
*mode_out = of_read(*mode_out);
return err;
}
int os_open_file(const char *file, struct openflags flags, int mode)
{
int fd, err, f = 0;
if (flags.r && flags.w)
f = O_RDWR;
else if (flags.r)
f = O_RDONLY;
else if (flags.w)
f = O_WRONLY;
else f = 0;
if (flags.s)
f |= O_SYNC;
if (flags.c)
f |= O_CREAT;
if (flags.t)
f |= O_TRUNC;
if (flags.e)
f |= O_EXCL;
if (flags.a)
f |= O_APPEND;
fd = open64(file, f, mode);
if (fd < 0)
return -errno;
if (flags.cl && fcntl(fd, F_SETFD, 1)) {
err = -errno;
close(fd);
return err;
}
return fd;
}
int os_connect_socket(const char *name)
{
struct sockaddr_un sock;
int fd, err;
sock.sun_family = AF_UNIX;
snprintf(sock.sun_path, sizeof(sock.sun_path), "%s", name);
fd = socket(AF_UNIX, SOCK_STREAM, 0);
if (fd < 0) {
err = -errno;
goto out;
}
err = connect(fd, (struct sockaddr *) &sock, sizeof(sock));
if (err) {
err = -errno;
goto out_close;
}
return fd;
out_close:
close(fd);
out:
return err;
}
void os_close_file(int fd)
{
close(fd);
}
int os_fsync_file(int fd)
{
if (fsync(fd) < 0)
return -errno;
return 0;
}
int os_seek_file(int fd, unsigned long long offset)
{
unsigned long long actual;
actual = lseek64(fd, offset, SEEK_SET);
if (actual != offset)
return -errno;
return 0;
}
int os_read_file(int fd, void *buf, int len)
{
int n = read(fd, buf, len);
if (n < 0)
return -errno;
return n;
}
int os_pread_file(int fd, void *buf, int len, unsigned long long offset)
{
int n = pread(fd, buf, len, offset);
if (n < 0)
return -errno;
return n;
}
int os_write_file(int fd, const void *buf, int len)
{
int n = write(fd, (void *) buf, len);
if (n < 0)
return -errno;
return n;
}
int os_sync_file(int fd)
{
int n = fdatasync(fd);
if (n < 0)
return -errno;
return n;
}
int os_pwrite_file(int fd, const void *buf, int len, unsigned long long offset)
{
int n = pwrite(fd, (void *) buf, len, offset);
if (n < 0)
return -errno;
return n;
}
int os_file_size(const char *file, unsigned long long *size_out)
{
struct uml_stat buf;
int err;
err = os_stat_file(file, &buf);
if (err < 0) {
printk(UM_KERN_ERR "Couldn't stat \"%s\" : err = %d\n", file,
-err);
return err;
}
if (S_ISBLK(buf.ust_mode)) {
int fd;
long blocks;
fd = open(file, O_RDONLY, 0);
if (fd < 0) {
err = -errno;
printk(UM_KERN_ERR "Couldn't open \"%s\", "
"errno = %d\n", file, errno);
return err;
}
if (ioctl(fd, BLKGETSIZE, &blocks) < 0) {
err = -errno;
printk(UM_KERN_ERR "Couldn't get the block size of "
"\"%s\", errno = %d\n", file, errno);
close(fd);
return err;
}
*size_out = ((long long) blocks) * 512;
close(fd);
}
else *size_out = buf.ust_size;
return 0;
}
int os_file_modtime(const char *file, long long *modtime)
{
struct uml_stat buf;
int err;
err = os_stat_file(file, &buf);
if (err < 0) {
printk(UM_KERN_ERR "Couldn't stat \"%s\" : err = %d\n", file,
-err);
return err;
}
*modtime = buf.ust_mtime;
return 0;
}
int os_set_exec_close(int fd)
{
int err;
CATCH_EINTR(err = fcntl(fd, F_SETFD, FD_CLOEXEC));
if (err < 0)
return -errno;
return err;
}
int os_pipe(int *fds, int stream, int close_on_exec)
{
int err, type = stream ? SOCK_STREAM : SOCK_DGRAM;
err = socketpair(AF_UNIX, type, 0, fds);
if (err < 0)
return -errno;
if (!close_on_exec)
return 0;
err = os_set_exec_close(fds[0]);
if (err < 0)
goto error;
err = os_set_exec_close(fds[1]);
if (err < 0)
goto error;
return 0;
error:
printk(UM_KERN_ERR "os_pipe : Setting FD_CLOEXEC failed, err = %d\n",
-err);
close(fds[1]);
close(fds[0]);
return err;
}
int os_set_fd_async(int fd)
{
int err, flags;
flags = fcntl(fd, F_GETFL);
if (flags < 0)
return -errno;
flags |= O_ASYNC | O_NONBLOCK;
if (fcntl(fd, F_SETFL, flags) < 0) {
err = -errno;
printk(UM_KERN_ERR "os_set_fd_async : failed to set O_ASYNC "
"and O_NONBLOCK on fd # %d, errno = %d\n", fd, errno);
return err;
}
if ((fcntl(fd, F_SETSIG, SIGIO) < 0) ||
(fcntl(fd, F_SETOWN, os_getpid()) < 0)) {
err = -errno;
printk(UM_KERN_ERR "os_set_fd_async : Failed to fcntl F_SETOWN "
"(or F_SETSIG) fd %d, errno = %d\n", fd, errno);
return err;
}
return 0;
}
int os_clear_fd_async(int fd)
{
int flags;
flags = fcntl(fd, F_GETFL);
if (flags < 0)
return -errno;
flags &= ~(O_ASYNC | O_NONBLOCK);
if (fcntl(fd, F_SETFL, flags) < 0)
return -errno;
return 0;
}
int os_set_fd_block(int fd, int blocking)
{
int flags;
flags = fcntl(fd, F_GETFL);
if (flags < 0)
return -errno;
if (blocking)
flags &= ~O_NONBLOCK;
else
flags |= O_NONBLOCK;
if (fcntl(fd, F_SETFL, flags) < 0)
return -errno;
return 0;
}
int os_accept_connection(int fd)
{
int new;
new = accept(fd, NULL, 0);
if (new < 0)
return -errno;
return new;
}
#ifndef SHUT_RD
#define SHUT_RD 0
#endif
#ifndef SHUT_WR
#define SHUT_WR 1
#endif
#ifndef SHUT_RDWR
#define SHUT_RDWR 2
#endif
int os_shutdown_socket(int fd, int r, int w)
{
int what, err;
if (r && w)
what = SHUT_RDWR;
else if (r)
what = SHUT_RD;
else if (w)
what = SHUT_WR;
else
return -EINVAL;
err = shutdown(fd, what);
if (err < 0)
return -errno;
return 0;
}
int os_rcv_fd(int fd, int *helper_pid_out)
{
int new, n;
char buf[CMSG_SPACE(sizeof(new))];
struct msghdr msg;
struct cmsghdr *cmsg;
struct iovec iov;
msg.msg_name = NULL;
msg.msg_namelen = 0;
iov = ((struct iovec) { .iov_base = helper_pid_out,
.iov_len = sizeof(*helper_pid_out) });
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_control = buf;
msg.msg_controllen = sizeof(buf);
msg.msg_flags = 0;
n = recvmsg(fd, &msg, 0);
if (n < 0)
return -errno;
else if (n != iov.iov_len)
*helper_pid_out = -1;
cmsg = CMSG_FIRSTHDR(&msg);
if (cmsg == NULL) {
printk(UM_KERN_ERR "rcv_fd didn't receive anything, "
"error = %d\n", errno);
return -1;
}
if ((cmsg->cmsg_level != SOL_SOCKET) ||
(cmsg->cmsg_type != SCM_RIGHTS)) {
printk(UM_KERN_ERR "rcv_fd didn't receive a descriptor\n");
return -1;
}
new = ((int *) CMSG_DATA(cmsg))[0];
return new;
}
int os_create_unix_socket(const char *file, int len, int close_on_exec)
{
struct sockaddr_un addr;
int sock, err;
sock = socket(PF_UNIX, SOCK_DGRAM, 0);
if (sock < 0)
return -errno;
if (close_on_exec) {
err = os_set_exec_close(sock);
if (err < 0)
printk(UM_KERN_ERR "create_unix_socket : "
"close_on_exec failed, err = %d", -err);
}
addr.sun_family = AF_UNIX;
snprintf(addr.sun_path, len, "%s", file);
err = bind(sock, (struct sockaddr *) &addr, sizeof(addr));
if (err < 0)
return -errno;
return sock;
}
void os_flush_stdout(void)
{
fflush(stdout);
}
int os_lock_file(int fd, int excl)
{
int type = excl ? F_WRLCK : F_RDLCK;
struct flock lock = ((struct flock) { .l_type = type,
.l_whence = SEEK_SET,
.l_start = 0,
.l_len = 0 } );
int err, save;
err = fcntl(fd, F_SETLK, &lock);
if (!err)
goto out;
save = -errno;
err = fcntl(fd, F_GETLK, &lock);
if (err) {
err = -errno;
goto out;
}
printk(UM_KERN_ERR "F_SETLK failed, file already locked by pid %d\n",
lock.l_pid);
err = save;
out:
return err;
}
unsigned os_major(unsigned long long dev)
{
return major(dev);
}
unsigned os_minor(unsigned long long dev)
{
return minor(dev);
}
unsigned long long os_makedev(unsigned major, unsigned minor)
{
return makedev(major, minor);
}
int os_falloc_punch(int fd, unsigned long long offset, int len)
{
int n = fallocate(fd, FALLOC_FL_PUNCH_HOLE|FALLOC_FL_KEEP_SIZE, offset, len);
if (n < 0)
return -errno;
return n;
}
int os_eventfd(unsigned int initval, int flags)
{
int fd = eventfd(initval, flags);
if (fd < 0)
return -errno;
return fd;
}
int os_sendmsg_fds(int fd, const void *buf, unsigned int len, const int *fds,
unsigned int fds_num)
{
struct iovec iov = {
.iov_base = (void *) buf,
.iov_len = len,
};
union {
char control[CMSG_SPACE(sizeof(*fds) * OS_SENDMSG_MAX_FDS)];
struct cmsghdr align;
} u;
unsigned int fds_size = sizeof(*fds) * fds_num;
struct msghdr msg = {
.msg_iov = &iov,
.msg_iovlen = 1,
.msg_control = u.control,
.msg_controllen = CMSG_SPACE(fds_size),
};
struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msg);
int err;
if (fds_num > OS_SENDMSG_MAX_FDS)
return -EINVAL;
memset(u.control, 0, sizeof(u.control));
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_RIGHTS;
cmsg->cmsg_len = CMSG_LEN(fds_size);
memcpy(CMSG_DATA(cmsg), fds, fds_size);
err = sendmsg(fd, &msg, 0);
if (err < 0)
return -errno;
return err;
}
int os_poll(unsigned int n, const int *fds)
{
/* currently need 2 FDs at most so avoid dynamic allocation */
struct pollfd pollfds[2] = {};
unsigned int i;
int ret;
if (n > ARRAY_SIZE(pollfds))
return -EINVAL;
for (i = 0; i < n; i++) {
pollfds[i].fd = fds[i];
pollfds[i].events = POLLIN;
}
ret = poll(pollfds, n, -1);
if (ret < 0)
return -errno;
/* Return the index of the available FD */
for (i = 0; i < n; i++) {
if (pollfds[i].revents)
return i;
}
return -EIO;
}