1 files changed, 79 insertions, 0 deletions

diff --git a/net/core/filter.c b/net/core/filter.c
index 22e3992..6c627bc 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -2410,6 +2410,12 @@ tc_cls_act_func_proto(enum bpf_func_id func_id)
 	}
 }
 
+static const struct bpf_func_proto *
+xdp_func_proto(enum bpf_func_id func_id)
+{
+	return sk_filter_func_proto(func_id);
+}
+
 static bool __is_valid_access(int off, int size, enum bpf_access_type type)
 {
 	if (off < 0 || off >= sizeof(struct __sk_buff))
@@ -2477,6 +2483,44 @@ static bool tc_cls_act_is_valid_access(int off, int size,
 	return __is_valid_access(off, size, type);
 }
 
+static bool __is_valid_xdp_access(int off, int size,
+				  enum bpf_access_type type)
+{
+	if (off < 0 || off >= sizeof(struct xdp_md))
+		return false;
+	if (off % size != 0)
+		return false;
+	if (size != 4)
+		return false;
+
+	return true;
+}
+
+static bool xdp_is_valid_access(int off, int size,
+				enum bpf_access_type type,
+				enum bpf_reg_type *reg_type)
+{
+	if (type == BPF_WRITE)
+		return false;
+
+	switch (off) {
+	case offsetof(struct xdp_md, data):
+		*reg_type = PTR_TO_PACKET;
+		break;
+	case offsetof(struct xdp_md, data_end):
+		*reg_type = PTR_TO_PACKET_END;
+		break;
+	}
+
+	return __is_valid_xdp_access(off, size, type);
+}
+
+void bpf_warn_invalid_xdp_action(u32 act)
+{
+	WARN_ONCE(1, "Illegal XDP return value %u, expect packet loss\n", act);
+}
+EXPORT_SYMBOL_GPL(bpf_warn_invalid_xdp_action);
+
 static u32 bpf_net_convert_ctx_access(enum bpf_access_type type, int dst_reg,
 				      int src_reg, int ctx_off,
 				      struct bpf_insn *insn_buf,
@@ -2628,6 +2672,29 @@ static u32 bpf_net_convert_ctx_access(enum bpf_access_type type, int dst_reg,
 	return insn - insn_buf;
 }
 
+static u32 xdp_convert_ctx_access(enum bpf_access_type type, int dst_reg,
+				  int src_reg, int ctx_off,
+				  struct bpf_insn *insn_buf,
+				  struct bpf_prog *prog)
+{
+	struct bpf_insn *insn = insn_buf;
+
+	switch (ctx_off) {
+	case offsetof(struct xdp_md, data):
+		*insn++ = BPF_LDX_MEM(bytes_to_bpf_size(FIELD_SIZEOF(struct xdp_buff, data)),
+				      dst_reg, src_reg,
+				      offsetof(struct xdp_buff, data));
+		break;
+	case offsetof(struct xdp_md, data_end):
+		*insn++ = BPF_LDX_MEM(bytes_to_bpf_size(FIELD_SIZEOF(struct xdp_buff, data_end)),
+				      dst_reg, src_reg,
+				      offsetof(struct xdp_buff, data_end));
+		break;
+	}
+
+	return insn - insn_buf;
+}
+
 static const struct bpf_verifier_ops sk_filter_ops = {
 	.get_func_proto		= sk_filter_func_proto,
 	.is_valid_access	= sk_filter_is_valid_access,
@@ -2640,6 +2707,12 @@ static const struct bpf_verifier_ops tc_cls_act_ops = {
 	.convert_ctx_access	= bpf_net_convert_ctx_access,
 };
 
+static const struct bpf_verifier_ops xdp_ops = {
+	.get_func_proto		= xdp_func_proto,
+	.is_valid_access	= xdp_is_valid_access,
+	.convert_ctx_access	= xdp_convert_ctx_access,
+};
+
 static struct bpf_prog_type_list sk_filter_type __read_mostly = {
 	.ops	= &sk_filter_ops,
 	.type	= BPF_PROG_TYPE_SOCKET_FILTER,
@@ -2655,11 +2728,17 @@ static struct bpf_prog_type_list sched_act_type __read_mostly = {
 	.type	= BPF_PROG_TYPE_SCHED_ACT,
 };
 
+static struct bpf_prog_type_list xdp_type __read_mostly = {
+	.ops	= &xdp_ops,
+	.type	= BPF_PROG_TYPE_XDP,
+};
+
 static int __init register_sk_filter_ops(void)
 {
 	bpf_register_prog_type(&sk_filter_type);
 	bpf_register_prog_type(&sched_cls_type);
 	bpf_register_prog_type(&sched_act_type);
+	bpf_register_prog_type(&xdp_type);
 
 	return 0;
 }