// SPDX-License-Identifier: GPL-2.0
|
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
|
#include <linux/init.h>
|
#include <linux/module.h>
|
#include <linux/umh.h>
|
#include <linux/bpfilter.h>
|
#include <linux/sched.h>
|
#include <linux/sched/signal.h>
|
#include <linux/fs.h>
|
#include <linux/file.h>
|
#include "msgfmt.h"
|
|
extern char bpfilter_umh_start;
|
extern char bpfilter_umh_end;
|
|
static void shutdown_umh(void)
|
{
|
struct umd_info *info = &bpfilter_ops.info;
|
struct pid *tgid = info->tgid;
|
|
if (tgid) {
|
kill_pid(tgid, SIGKILL, 1);
|
wait_event(tgid->wait_pidfd, thread_group_exited(tgid));
|
bpfilter_umh_cleanup(info);
|
}
|
}
|
|
static void __stop_umh(void)
|
{
|
if (IS_ENABLED(CONFIG_INET))
|
shutdown_umh();
|
}
|
|
static int bpfilter_send_req(struct mbox_request *req)
|
{
|
struct mbox_reply reply;
|
loff_t pos = 0;
|
ssize_t n;
|
|
if (!bpfilter_ops.info.tgid)
|
return -EFAULT;
|
pos = 0;
|
n = kernel_write(bpfilter_ops.info.pipe_to_umh, req, sizeof(*req),
|
&pos);
|
if (n != sizeof(*req)) {
|
pr_err("write fail %zd\n", n);
|
goto stop;
|
}
|
pos = 0;
|
n = kernel_read(bpfilter_ops.info.pipe_from_umh, &reply, sizeof(reply),
|
&pos);
|
if (n != sizeof(reply)) {
|
pr_err("read fail %zd\n", n);
|
goto stop;
|
}
|
return reply.status;
|
stop:
|
__stop_umh();
|
return -EFAULT;
|
}
|
|
static int bpfilter_process_sockopt(struct sock *sk, int optname,
|
sockptr_t optval, unsigned int optlen,
|
bool is_set)
|
{
|
struct mbox_request req = {
|
.is_set = is_set,
|
.pid = current->pid,
|
.cmd = optname,
|
.addr = (uintptr_t)optval.user,
|
.len = optlen,
|
};
|
if (uaccess_kernel() || sockptr_is_kernel(optval)) {
|
pr_err("kernel access not supported\n");
|
return -EFAULT;
|
}
|
return bpfilter_send_req(&req);
|
}
|
|
static int start_umh(void)
|
{
|
struct mbox_request req = { .pid = current->pid };
|
int err;
|
|
/* fork usermode process */
|
err = fork_usermode_driver(&bpfilter_ops.info);
|
if (err)
|
return err;
|
pr_info("Loaded bpfilter_umh pid %d\n", pid_nr(bpfilter_ops.info.tgid));
|
|
/* health check that usermode process started correctly */
|
if (bpfilter_send_req(&req) != 0) {
|
shutdown_umh();
|
return -EFAULT;
|
}
|
|
return 0;
|
}
|
|
static int __init load_umh(void)
|
{
|
int err;
|
|
err = umd_load_blob(&bpfilter_ops.info,
|
&bpfilter_umh_start,
|
&bpfilter_umh_end - &bpfilter_umh_start);
|
if (err)
|
return err;
|
|
mutex_lock(&bpfilter_ops.lock);
|
err = start_umh();
|
if (!err && IS_ENABLED(CONFIG_INET)) {
|
bpfilter_ops.sockopt = &bpfilter_process_sockopt;
|
bpfilter_ops.start = &start_umh;
|
}
|
mutex_unlock(&bpfilter_ops.lock);
|
if (err)
|
umd_unload_blob(&bpfilter_ops.info);
|
return err;
|
}
|
|
static void __exit fini_umh(void)
|
{
|
mutex_lock(&bpfilter_ops.lock);
|
if (IS_ENABLED(CONFIG_INET)) {
|
shutdown_umh();
|
bpfilter_ops.start = NULL;
|
bpfilter_ops.sockopt = NULL;
|
}
|
mutex_unlock(&bpfilter_ops.lock);
|
|
umd_unload_blob(&bpfilter_ops.info);
|
}
|
module_init(load_umh);
|
module_exit(fini_umh);
|
MODULE_LICENSE("GPL");
|
MODULE_IMPORT_NS(VFS_internal_I_am_really_a_filesystem_and_am_NOT_a_driver);
|
