diff options
Diffstat (limited to 'net/bpfilter/bpfilter_kern.c')
-rw-r--r-- | net/bpfilter/bpfilter_kern.c | 76 |
1 files changed, 42 insertions, 34 deletions
diff --git a/net/bpfilter/bpfilter_kern.c b/net/bpfilter/bpfilter_kern.c index 7acfc83087d5..7ee4fea93637 100644 --- a/net/bpfilter/bpfilter_kern.c +++ b/net/bpfilter/bpfilter_kern.c @@ -13,39 +13,24 @@ 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); - -static void shutdown_umh(struct umh_info *info) +static void shutdown_umh(void) { struct task_struct *tsk; - if (!info->pid) + if (bpfilter_ops.stop) return; - tsk = get_pid_task(find_vpid(info->pid), PIDTYPE_PID); + + tsk = get_pid_task(find_vpid(bpfilter_ops.info.pid), PIDTYPE_PID); if (tsk) { 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); - } -} - -static void stop_umh(void) -{ - mutex_lock(&bpfilter_lock); - __stop_umh(); - mutex_unlock(&bpfilter_lock); + if (IS_ENABLED(CONFIG_INET)) + shutdown_umh(); } static int __bpfilter_process_sockopt(struct sock *sk, int optname, @@ -63,10 +48,10 @@ static int __bpfilter_process_sockopt(struct sock *sk, int optname, req.cmd = 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 +59,8 @@ 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(); @@ -83,37 +69,59 @@ static int __bpfilter_process_sockopt(struct sock *sk, int optname, } ret = reply.status; out: - mutex_unlock(&bpfilter_lock); return ret; } -static int __init load_umh(void) +static int start_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); + bpfilter_ops.stop = false; + 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) { - stop_umh(); + shutdown_umh(); return -EFAULT; } - if (IS_ENABLED(CONFIG_INET)) - bpfilter_process_sockopt = &__bpfilter_process_sockopt; return 0; } +static int __init load_umh(void) +{ + int err; + + mutex_lock(&bpfilter_ops.lock); + if (!bpfilter_ops.stop) { + err = -EFAULT; + goto out; + } + err = start_umh(); + if (!err && IS_ENABLED(CONFIG_INET)) { + bpfilter_ops.sockopt = &__bpfilter_process_sockopt; + bpfilter_ops.start = &start_umh; + } +out: + mutex_unlock(&bpfilter_ops.lock); + return err; +} + static void __exit fini_umh(void) { - stop_umh(); + 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); } module_init(load_umh); module_exit(fini_umh); |