1 files changed, 140 insertions, 0 deletions
diff --git a/net/smc/smc_hs_bpf.c b/net/smc/smc_hs_bpf.c
new file mode 100644
index 000000000000..063d23d85850
--- /dev/null
+++ b/net/smc/smc_hs_bpf.c
@@ -0,0 +1,140 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  Shared Memory Communications over RDMA (SMC-R) and RoCE
+ *
+ *  Generic hook for SMC handshake flow.
+ *
+ *  Copyright IBM Corp. 2016
+ *  Copyright (c) 2025, Alibaba Inc.
+ *
+ *  Author: D. Wythe <alibuda@linux.alibaba.com>
+ */
+
+#include <linux/bpf_verifier.h>
+#include <linux/bpf.h>
+#include <linux/btf.h>
+#include <linux/rculist.h>
+
+#include "smc_hs_bpf.h"
+
+static DEFINE_SPINLOCK(smc_hs_ctrl_list_lock);
+static LIST_HEAD(smc_hs_ctrl_list);
+
+static int smc_hs_ctrl_reg(struct smc_hs_ctrl *ctrl)
+{
+	int ret = 0;
+
+	spin_lock(&smc_hs_ctrl_list_lock);
+	/* already exist or duplicate name */
+	if (smc_hs_ctrl_find_by_name(ctrl->name))
+		ret = -EEXIST;
+	else
+		list_add_tail_rcu(&ctrl->list, &smc_hs_ctrl_list);
+	spin_unlock(&smc_hs_ctrl_list_lock);
+	return ret;
+}
+
+static void smc_hs_ctrl_unreg(struct smc_hs_ctrl *ctrl)
+{
+	spin_lock(&smc_hs_ctrl_list_lock);
+	list_del_rcu(&ctrl->list);
+	spin_unlock(&smc_hs_ctrl_list_lock);
+
+	/* Ensure that all readers to complete */
+	synchronize_rcu();
+}
+
+struct smc_hs_ctrl *smc_hs_ctrl_find_by_name(const char *name)
+{
+	struct smc_hs_ctrl *ctrl;
+
+	list_for_each_entry_rcu(ctrl, &smc_hs_ctrl_list, list) {
+		if (strcmp(ctrl->name, name) == 0)
+			return ctrl;
+	}
+	return NULL;
+}
+
+static int __smc_bpf_stub_set_tcp_option(struct tcp_sock *tp) { return 1; }
+static int __smc_bpf_stub_set_tcp_option_cond(const struct tcp_sock *tp,
+					      struct inet_request_sock *ireq)
+{
+	return 1;
+}
+
+static struct smc_hs_ctrl __smc_bpf_hs_ctrl = {
+	.syn_option	= __smc_bpf_stub_set_tcp_option,
+	.synack_option	= __smc_bpf_stub_set_tcp_option_cond,
+};
+
+static int smc_bpf_hs_ctrl_init(struct btf *btf) { return 0; }
+
+static int smc_bpf_hs_ctrl_reg(void *kdata, struct bpf_link *link)
+{
+	if (link)
+		return -EOPNOTSUPP;
+
+	return smc_hs_ctrl_reg(kdata);
+}
+
+static void smc_bpf_hs_ctrl_unreg(void *kdata, struct bpf_link *link)
+{
+	smc_hs_ctrl_unreg(kdata);
+}
+
+static int smc_bpf_hs_ctrl_init_member(const struct btf_type *t,
+				       const struct btf_member *member,
+				       void *kdata, const void *udata)
+{
+	const struct smc_hs_ctrl *u_ctrl;
+	struct smc_hs_ctrl *k_ctrl;
+	u32 moff;
+
+	u_ctrl = (const struct smc_hs_ctrl *)udata;
+	k_ctrl = (struct smc_hs_ctrl *)kdata;
+
+	moff = __btf_member_bit_offset(t, member) / 8;
+	switch (moff) {
+	case offsetof(struct smc_hs_ctrl, name):
+		if (bpf_obj_name_cpy(k_ctrl->name, u_ctrl->name,
+				     sizeof(u_ctrl->name)) <= 0)
+			return -EINVAL;
+		return 1;
+	case offsetof(struct smc_hs_ctrl, flags):
+		if (u_ctrl->flags & ~SMC_HS_CTRL_ALL_FLAGS)
+			return -EINVAL;
+		k_ctrl->flags = u_ctrl->flags;
+		return 1;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static const struct bpf_func_proto *
+bpf_smc_hs_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
+{
+	return bpf_base_func_proto(func_id, prog);
+}
+
+static const struct bpf_verifier_ops smc_bpf_verifier_ops = {
+	.get_func_proto		= bpf_smc_hs_func_proto,
+	.is_valid_access	= bpf_tracing_btf_ctx_access,
+};
+
+static struct bpf_struct_ops bpf_smc_hs_ctrl_ops = {
+	.name		= "smc_hs_ctrl",
+	.init		= smc_bpf_hs_ctrl_init,
+	.reg		= smc_bpf_hs_ctrl_reg,
+	.unreg		= smc_bpf_hs_ctrl_unreg,
+	.cfi_stubs	= &__smc_bpf_hs_ctrl,
+	.verifier_ops	= &smc_bpf_verifier_ops,
+	.init_member	= smc_bpf_hs_ctrl_init_member,
+	.owner		= THIS_MODULE,
+};
+
+int bpf_smc_hs_ctrl_init(void)
+{
+	return register_bpf_struct_ops(&bpf_smc_hs_ctrl_ops, smc_hs_ctrl);
+}