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-rw-r--r--kernel/bpf/offload.c182
1 files changed, 182 insertions, 0 deletions
diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c
new file mode 100644
index 000000000000..5553e0e2f8b1
--- /dev/null
+++ b/kernel/bpf/offload.c
@@ -0,0 +1,182 @@
+#include <linux/bpf.h>
+#include <linux/bpf_verifier.h>
+#include <linux/bug.h>
+#include <linux/list.h>
+#include <linux/netdevice.h>
+#include <linux/printk.h>
+#include <linux/rtnetlink.h>
+
+/* protected by RTNL */
+static LIST_HEAD(bpf_prog_offload_devs);
+
+int bpf_prog_offload_init(struct bpf_prog *prog, union bpf_attr *attr)
+{
+ struct net *net = current->nsproxy->net_ns;
+ struct bpf_dev_offload *offload;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ if (attr->prog_flags)
+ return -EINVAL;
+
+ offload = kzalloc(sizeof(*offload), GFP_USER);
+ if (!offload)
+ return -ENOMEM;
+
+ offload->prog = prog;
+ init_waitqueue_head(&offload->verifier_done);
+
+ rtnl_lock();
+ offload->netdev = __dev_get_by_index(net, attr->prog_target_ifindex);
+ if (!offload->netdev) {
+ rtnl_unlock();
+ kfree(offload);
+ return -EINVAL;
+ }
+
+ prog->aux->offload = offload;
+ list_add_tail(&offload->offloads, &bpf_prog_offload_devs);
+ rtnl_unlock();
+
+ return 0;
+}
+
+static int __bpf_offload_ndo(struct bpf_prog *prog, enum bpf_netdev_command cmd,
+ struct netdev_bpf *data)
+{
+ struct net_device *netdev = prog->aux->offload->netdev;
+
+ ASSERT_RTNL();
+
+ if (!netdev)
+ return -ENODEV;
+ if (!netdev->netdev_ops->ndo_bpf)
+ return -EOPNOTSUPP;
+
+ data->command = cmd;
+
+ return netdev->netdev_ops->ndo_bpf(netdev, data);
+}
+
+int bpf_prog_offload_verifier_prep(struct bpf_verifier_env *env)
+{
+ struct netdev_bpf data = {};
+ int err;
+
+ data.verifier.prog = env->prog;
+
+ rtnl_lock();
+ err = __bpf_offload_ndo(env->prog, BPF_OFFLOAD_VERIFIER_PREP, &data);
+ if (err)
+ goto exit_unlock;
+
+ env->dev_ops = data.verifier.ops;
+
+ env->prog->aux->offload->dev_state = true;
+ env->prog->aux->offload->verifier_running = true;
+exit_unlock:
+ rtnl_unlock();
+ return err;
+}
+
+static void __bpf_prog_offload_destroy(struct bpf_prog *prog)
+{
+ struct bpf_dev_offload *offload = prog->aux->offload;
+ struct netdev_bpf data = {};
+
+ data.offload.prog = prog;
+
+ if (offload->verifier_running)
+ wait_event(offload->verifier_done, !offload->verifier_running);
+
+ if (offload->dev_state)
+ WARN_ON(__bpf_offload_ndo(prog, BPF_OFFLOAD_DESTROY, &data));
+
+ offload->dev_state = false;
+ list_del_init(&offload->offloads);
+ offload->netdev = NULL;
+}
+
+void bpf_prog_offload_destroy(struct bpf_prog *prog)
+{
+ struct bpf_dev_offload *offload = prog->aux->offload;
+
+ offload->verifier_running = false;
+ wake_up(&offload->verifier_done);
+
+ rtnl_lock();
+ __bpf_prog_offload_destroy(prog);
+ rtnl_unlock();
+
+ kfree(offload);
+}
+
+static int bpf_prog_offload_translate(struct bpf_prog *prog)
+{
+ struct bpf_dev_offload *offload = prog->aux->offload;
+ struct netdev_bpf data = {};
+ int ret;
+
+ data.offload.prog = prog;
+
+ offload->verifier_running = false;
+ wake_up(&offload->verifier_done);
+
+ rtnl_lock();
+ ret = __bpf_offload_ndo(prog, BPF_OFFLOAD_TRANSLATE, &data);
+ rtnl_unlock();
+
+ return ret;
+}
+
+static unsigned int bpf_prog_warn_on_exec(const void *ctx,
+ const struct bpf_insn *insn)
+{
+ WARN(1, "attempt to execute device eBPF program on the host!");
+ return 0;
+}
+
+int bpf_prog_offload_compile(struct bpf_prog *prog)
+{
+ prog->bpf_func = bpf_prog_warn_on_exec;
+
+ return bpf_prog_offload_translate(prog);
+}
+
+const struct bpf_prog_ops bpf_offload_prog_ops = {
+};
+
+static int bpf_offload_notification(struct notifier_block *notifier,
+ ulong event, void *ptr)
+{
+ struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
+ struct bpf_dev_offload *offload, *tmp;
+
+ ASSERT_RTNL();
+
+ switch (event) {
+ case NETDEV_UNREGISTER:
+ list_for_each_entry_safe(offload, tmp, &bpf_prog_offload_devs,
+ offloads) {
+ if (offload->netdev == netdev)
+ __bpf_prog_offload_destroy(offload->prog);
+ }
+ break;
+ default:
+ break;
+ }
+ return NOTIFY_OK;
+}
+
+static struct notifier_block bpf_offload_notifier = {
+ .notifier_call = bpf_offload_notification,
+};
+
+static int __init bpf_offload_init(void)
+{
+ register_netdevice_notifier(&bpf_offload_notifier);
+ return 0;
+}
+
+subsys_initcall(bpf_offload_init);