From 5b4cb650e569db2e6a09d2fa0ef8eb789a0ac5d8 Mon Sep 17 00:00:00 2001 From: Taehee Yoo Date: Wed, 9 Jan 2019 02:24:34 +0900 Subject: [PATCH] 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: Taehee Yoo Signed-off-by: David S. Miller --- include/linux/bpfilter.h | 11 ++++++++--- net/bpfilter/bpfilter_kern.c | 23 ++++++++++------------- net/ipv4/bpfilter/sockopt.c | 33 ++++++++++++++++++++++++++------- 3 files changed, 44 insertions(+), 23 deletions(-) diff --git a/include/linux/bpfilter.h b/include/linux/bpfilter.h index f02cee0225d4..70ffeed280e9 100644 --- a/include/linux/bpfilter.h +++ b/include/linux/bpfilter.h @@ -3,13 +3,18 @@ #define _LINUX_BPFILTER_H #include +#include struct sock; int bpfilter_ip_set_sockopt(struct sock *sk, int optname, char __user *optval, unsigned int optlen); int bpfilter_ip_get_sockopt(struct sock *sk, int optname, char __user *optval, int __user *optlen); -extern int (*bpfilter_process_sockopt)(struct sock *sk, int optname, - char __user *optval, - unsigned int optlen, bool is_set); +struct bpfilter_umh_ops { + struct umh_info info; + int (*sockopt)(struct sock *sk, int optname, + char __user *optval, + unsigned int optlen, bool is_set); +}; +extern struct bpfilter_umh_ops bpfilter_ops; #endif diff --git a/net/bpfilter/bpfilter_kern.c b/net/bpfilter/bpfilter_kern.c index 7acfc83087d5..a68940b74c01 100644 --- a/net/bpfilter/bpfilter_kern.c +++ b/net/bpfilter/bpfilter_kern.c @@ -13,7 +13,6 @@ extern char bpfilter_umh_start; extern char bpfilter_umh_end; -static struct umh_info info; /* since ip_getsockopt() can run in parallel, serialize access to umh */ static DEFINE_MUTEX(bpfilter_lock); @@ -28,16 +27,13 @@ static void shutdown_umh(struct umh_info *info) force_sig(SIGKILL, tsk); put_task_struct(tsk); } - fput(info->pipe_to_umh); - fput(info->pipe_from_umh); - info->pid = 0; } static void __stop_umh(void) { if (IS_ENABLED(CONFIG_INET)) { - bpfilter_process_sockopt = NULL; - shutdown_umh(&info); + bpfilter_ops.sockopt = NULL; + shutdown_umh(&bpfilter_ops.info); } } @@ -64,9 +60,10 @@ static int __bpfilter_process_sockopt(struct sock *sk, int optname, req.addr = (long __force __user)optval; req.len = optlen; mutex_lock(&bpfilter_lock); - if (!info.pid) + if (!bpfilter_ops.info.pid) 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)) { pr_err("write fail %zd\n", n); __stop_umh(); @@ -74,7 +71,8 @@ static int __bpfilter_process_sockopt(struct sock *sk, int optname, goto out; } 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)) { pr_err("read fail %zd\n", n); __stop_umh(); @@ -92,13 +90,12 @@ static int __init load_umh(void) int err; /* fork usermode process */ - info.cmdline = "bpfilter_umh"; err = fork_usermode_blob(&bpfilter_umh_start, &bpfilter_umh_end - &bpfilter_umh_start, - &info); + &bpfilter_ops.info); if (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 */ if (__bpfilter_process_sockopt(NULL, 0, NULL, 0, 0) != 0) { @@ -106,7 +103,7 @@ static int __init load_umh(void) return -EFAULT; } if (IS_ENABLED(CONFIG_INET)) - bpfilter_process_sockopt = &__bpfilter_process_sockopt; + bpfilter_ops.sockopt = &__bpfilter_process_sockopt; return 0; } diff --git a/net/ipv4/bpfilter/sockopt.c b/net/ipv4/bpfilter/sockopt.c index 5e04ed25bc0e..c326cfbc0f62 100644 --- a/net/ipv4/bpfilter/sockopt.c +++ b/net/ipv4/bpfilter/sockopt.c @@ -1,28 +1,37 @@ // SPDX-License-Identifier: GPL-2.0 +#include +#include #include #include #include #include #include +#include +#include -int (*bpfilter_process_sockopt)(struct sock *sk, int optname, - char __user *optval, - unsigned int optlen, bool is_set); -EXPORT_SYMBOL_GPL(bpfilter_process_sockopt); +struct bpfilter_umh_ops bpfilter_ops; +EXPORT_SYMBOL_GPL(bpfilter_ops); + +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, char __user *optval, unsigned int optlen, bool is_set) { - if (!bpfilter_process_sockopt) { + if (!bpfilter_ops.sockopt) { int err = request_module("bpfilter"); if (err) return err; - if (!bpfilter_process_sockopt) + if (!bpfilter_ops.sockopt) 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, @@ -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); } + +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);