Commit 5b4cb650 authored by Taehee Yoo's avatar Taehee Yoo Committed by David S. Miller
Browse files

net: bpfilter: use cleanup callback to release umh_info



Now, UMH process is killed, do_exit() calls the umh_info->cleanup callback
to release members of the umh_info.
This patch makes bpfilter_umh's cleanup routine to use the
umh_info->cleanup callback.
Signed-off-by: default avatarTaehee Yoo <ap420073@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 73ab1cb2
...@@ -3,13 +3,18 @@ ...@@ -3,13 +3,18 @@
#define _LINUX_BPFILTER_H #define _LINUX_BPFILTER_H
#include <uapi/linux/bpfilter.h> #include <uapi/linux/bpfilter.h>
#include <linux/umh.h>
struct sock; struct sock;
int bpfilter_ip_set_sockopt(struct sock *sk, int optname, char __user *optval, int bpfilter_ip_set_sockopt(struct sock *sk, int optname, char __user *optval,
unsigned int optlen); unsigned int optlen);
int bpfilter_ip_get_sockopt(struct sock *sk, int optname, char __user *optval, int bpfilter_ip_get_sockopt(struct sock *sk, int optname, char __user *optval,
int __user *optlen); int __user *optlen);
extern int (*bpfilter_process_sockopt)(struct sock *sk, int optname, struct bpfilter_umh_ops {
char __user *optval, struct umh_info info;
unsigned int optlen, bool is_set); int (*sockopt)(struct sock *sk, int optname,
char __user *optval,
unsigned int optlen, bool is_set);
};
extern struct bpfilter_umh_ops bpfilter_ops;
#endif #endif
...@@ -13,7 +13,6 @@ ...@@ -13,7 +13,6 @@
extern char bpfilter_umh_start; extern char bpfilter_umh_start;
extern char bpfilter_umh_end; extern char bpfilter_umh_end;
static struct umh_info info;
/* since ip_getsockopt() can run in parallel, serialize access to umh */ /* since ip_getsockopt() can run in parallel, serialize access to umh */
static DEFINE_MUTEX(bpfilter_lock); static DEFINE_MUTEX(bpfilter_lock);
...@@ -28,16 +27,13 @@ static void shutdown_umh(struct umh_info *info) ...@@ -28,16 +27,13 @@ static void shutdown_umh(struct umh_info *info)
force_sig(SIGKILL, tsk); force_sig(SIGKILL, tsk);
put_task_struct(tsk); put_task_struct(tsk);
} }
fput(info->pipe_to_umh);
fput(info->pipe_from_umh);
info->pid = 0;
} }
static void __stop_umh(void) static void __stop_umh(void)
{ {
if (IS_ENABLED(CONFIG_INET)) { if (IS_ENABLED(CONFIG_INET)) {
bpfilter_process_sockopt = NULL; bpfilter_ops.sockopt = NULL;
shutdown_umh(&info); shutdown_umh(&bpfilter_ops.info);
} }
} }
...@@ -64,9 +60,10 @@ static int __bpfilter_process_sockopt(struct sock *sk, int optname, ...@@ -64,9 +60,10 @@ static int __bpfilter_process_sockopt(struct sock *sk, int optname,
req.addr = (long __force __user)optval; req.addr = (long __force __user)optval;
req.len = optlen; req.len = optlen;
mutex_lock(&bpfilter_lock); mutex_lock(&bpfilter_lock);
if (!info.pid) if (!bpfilter_ops.info.pid)
goto out; goto out;
n = __kernel_write(info.pipe_to_umh, &req, sizeof(req), &pos); n = __kernel_write(bpfilter_ops.info.pipe_to_umh, &req, sizeof(req),
&pos);
if (n != sizeof(req)) { if (n != sizeof(req)) {
pr_err("write fail %zd\n", n); pr_err("write fail %zd\n", n);
__stop_umh(); __stop_umh();
...@@ -74,7 +71,8 @@ static int __bpfilter_process_sockopt(struct sock *sk, int optname, ...@@ -74,7 +71,8 @@ static int __bpfilter_process_sockopt(struct sock *sk, int optname,
goto out; goto out;
} }
pos = 0; pos = 0;
n = kernel_read(info.pipe_from_umh, &reply, sizeof(reply), &pos); n = kernel_read(bpfilter_ops.info.pipe_from_umh, &reply, sizeof(reply),
&pos);
if (n != sizeof(reply)) { if (n != sizeof(reply)) {
pr_err("read fail %zd\n", n); pr_err("read fail %zd\n", n);
__stop_umh(); __stop_umh();
...@@ -92,13 +90,12 @@ static int __init load_umh(void) ...@@ -92,13 +90,12 @@ static int __init load_umh(void)
int err; int err;
/* fork usermode process */ /* fork usermode process */
info.cmdline = "bpfilter_umh";
err = fork_usermode_blob(&bpfilter_umh_start, err = fork_usermode_blob(&bpfilter_umh_start,
&bpfilter_umh_end - &bpfilter_umh_start, &bpfilter_umh_end - &bpfilter_umh_start,
&info); &bpfilter_ops.info);
if (err) if (err)
return err; return err;
pr_info("Loaded bpfilter_umh pid %d\n", info.pid); pr_info("Loaded bpfilter_umh pid %d\n", bpfilter_ops.info.pid);
/* health check that usermode process started correctly */ /* health check that usermode process started correctly */
if (__bpfilter_process_sockopt(NULL, 0, NULL, 0, 0) != 0) { if (__bpfilter_process_sockopt(NULL, 0, NULL, 0, 0) != 0) {
...@@ -106,7 +103,7 @@ static int __init load_umh(void) ...@@ -106,7 +103,7 @@ static int __init load_umh(void)
return -EFAULT; return -EFAULT;
} }
if (IS_ENABLED(CONFIG_INET)) if (IS_ENABLED(CONFIG_INET))
bpfilter_process_sockopt = &__bpfilter_process_sockopt; bpfilter_ops.sockopt = &__bpfilter_process_sockopt;
return 0; return 0;
} }
......
// SPDX-License-Identifier: GPL-2.0 // SPDX-License-Identifier: GPL-2.0
#include <linux/init.h>
#include <linux/module.h>
#include <linux/uaccess.h> #include <linux/uaccess.h>
#include <linux/bpfilter.h> #include <linux/bpfilter.h>
#include <uapi/linux/bpf.h> #include <uapi/linux/bpf.h>
#include <linux/wait.h> #include <linux/wait.h>
#include <linux/kmod.h> #include <linux/kmod.h>
#include <linux/fs.h>
#include <linux/file.h>
int (*bpfilter_process_sockopt)(struct sock *sk, int optname, struct bpfilter_umh_ops bpfilter_ops;
char __user *optval, EXPORT_SYMBOL_GPL(bpfilter_ops);
unsigned int optlen, bool is_set);
EXPORT_SYMBOL_GPL(bpfilter_process_sockopt); static void bpfilter_umh_cleanup(struct umh_info *info)
{
fput(info->pipe_to_umh);
fput(info->pipe_from_umh);
info->pid = 0;
}
static int bpfilter_mbox_request(struct sock *sk, int optname, static int bpfilter_mbox_request(struct sock *sk, int optname,
char __user *optval, char __user *optval,
unsigned int optlen, bool is_set) unsigned int optlen, bool is_set)
{ {
if (!bpfilter_process_sockopt) { if (!bpfilter_ops.sockopt) {
int err = request_module("bpfilter"); int err = request_module("bpfilter");
if (err) if (err)
return err; return err;
if (!bpfilter_process_sockopt) if (!bpfilter_ops.sockopt)
return -ECHILD; return -ECHILD;
} }
return bpfilter_process_sockopt(sk, optname, optval, optlen, is_set); return bpfilter_ops.sockopt(sk, optname, optval, optlen, is_set);
} }
int bpfilter_ip_set_sockopt(struct sock *sk, int optname, char __user *optval, int bpfilter_ip_set_sockopt(struct sock *sk, int optname, char __user *optval,
...@@ -41,3 +50,13 @@ int bpfilter_ip_get_sockopt(struct sock *sk, int optname, char __user *optval, ...@@ -41,3 +50,13 @@ int bpfilter_ip_get_sockopt(struct sock *sk, int optname, char __user *optval,
return bpfilter_mbox_request(sk, optname, optval, len, false); return bpfilter_mbox_request(sk, optname, optval, len, false);
} }
static int __init bpfilter_sockopt_init(void)
{
bpfilter_ops.info.cmdline = "bpfilter_umh";
bpfilter_ops.info.cleanup = &bpfilter_umh_cleanup;
return 0;
}
module_init(bpfilter_sockopt_init);
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