tc: bpf: generalize pedit action (608cd71a) · Commits · 戴 / test

include/linux/bpf.h

+1 −0

Original line number	Original line	Diff line number	Diff line
	@@ -59,6 +59,7 @@ enum bpf_arg_type {
	ARG_PTR_TO_STACK, /* any pointer to eBPF program stack */		ARG_PTR_TO_STACK, /* any pointer to eBPF program stack */
	ARG_CONST_STACK_SIZE, /* number of bytes accessed from stack */		ARG_CONST_STACK_SIZE, /* number of bytes accessed from stack */

			ARG_PTR_TO_CTX, /* pointer to context */
	ARG_ANYTHING, /* any (initialized) argument is ok */		ARG_ANYTHING, /* any (initialized) argument is ok */
	};		};

include/uapi/linux/bpf.h

+1 −0

Original line number	Original line	Diff line number	Diff line
	@@ -168,6 +168,7 @@ enum bpf_func_id {
	BPF_FUNC_map_delete_elem, /* int map_delete_elem(&map, &key) */		BPF_FUNC_map_delete_elem, /* int map_delete_elem(&map, &key) */
	BPF_FUNC_get_prandom_u32, /* u32 prandom_u32(void) */		BPF_FUNC_get_prandom_u32, /* u32 prandom_u32(void) */
	BPF_FUNC_get_smp_processor_id, /* u32 raw_smp_processor_id(void) */		BPF_FUNC_get_smp_processor_id, /* u32 raw_smp_processor_id(void) */
			BPF_FUNC_skb_store_bytes, /* int skb_store_bytes(skb, offset, from, len) */
	__BPF_FUNC_MAX_ID,		__BPF_FUNC_MAX_ID,
	};		};

kernel/bpf/verifier.c

+2 −0

Original line number	Original line	Diff line number	Diff line
	@@ -773,6 +773,8 @@ static int check_func_arg(struct verifier_env *env, u32 regno,
	expected_type = CONST_IMM;		expected_type = CONST_IMM;
	} else if (arg_type == ARG_CONST_MAP_PTR) {		} else if (arg_type == ARG_CONST_MAP_PTR) {
	expected_type = CONST_PTR_TO_MAP;		expected_type = CONST_PTR_TO_MAP;
			} else if (arg_type == ARG_PTR_TO_CTX) {
			expected_type = PTR_TO_CTX;
	} else {		} else {
	verbose("unsupported arg_type %d\n", arg_type);		verbose("unsupported arg_type %d\n", arg_type);
	return -EFAULT;		return -EFAULT;

net/core/filter.c

+69 −2

Original line number	Original line	Diff line number	Diff line
	@@ -1175,6 +1175,56 @@ int sk_attach_bpf(u32 ufd, struct sock *sk)
	return 0;		return 0;
	}		}

			static u64 bpf_skb_store_bytes(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
			{
			struct sk_buff skb = (struct sk_buff ) (long) r1;
			unsigned int offset = (unsigned int) r2;
			void from = (void ) (long) r3;
			unsigned int len = (unsigned int) r4;
			char buf[16];
			void *ptr;

			/* bpf verifier guarantees that:
			* 'from' pointer points to bpf program stack
			* 'len' bytes of it were initialized
			* 'len' > 0
			* 'skb' is a valid pointer to 'struct sk_buff'
			*
			* so check for invalid 'offset' and too large 'len'
			*/
			if (offset > 0xffff \|\| len > sizeof(buf))
			return -EFAULT;

			if (skb_cloned(skb) && !skb_clone_writable(skb, offset + len))
			return -EFAULT;

			ptr = skb_header_pointer(skb, offset, len, buf);
			if (unlikely(!ptr))
			return -EFAULT;

			skb_postpull_rcsum(skb, ptr, len);

			memcpy(ptr, from, len);

			if (ptr == buf)
			/* skb_store_bits cannot return -EFAULT here */
			skb_store_bits(skb, offset, ptr, len);

			if (skb->ip_summed == CHECKSUM_COMPLETE)
			skb->csum = csum_add(skb->csum, csum_partial(ptr, len, 0));
			return 0;
			}

			const struct bpf_func_proto bpf_skb_store_bytes_proto = {
			.func = bpf_skb_store_bytes,
			.gpl_only = false,
			.ret_type = RET_INTEGER,
			.arg1_type = ARG_PTR_TO_CTX,
			.arg2_type = ARG_ANYTHING,
			.arg3_type = ARG_PTR_TO_STACK,
			.arg4_type = ARG_CONST_STACK_SIZE,
			};

	static const struct bpf_func_proto *		static const struct bpf_func_proto *
	sk_filter_func_proto(enum bpf_func_id func_id)		sk_filter_func_proto(enum bpf_func_id func_id)
	{		{
	@@ -1194,6 +1244,17 @@ sk_filter_func_proto(enum bpf_func_id func_id)
	}		}
	}		}

			static const struct bpf_func_proto *
			tc_cls_act_func_proto(enum bpf_func_id func_id)
			{
			switch (func_id) {
			case BPF_FUNC_skb_store_bytes:
			return &bpf_skb_store_bytes_proto;
			default:
			return sk_filter_func_proto(func_id);
			}
			}

	static bool sk_filter_is_valid_access(int off, int size,		static bool sk_filter_is_valid_access(int off, int size,
	enum bpf_access_type type)		enum bpf_access_type type)
	{		{
	@@ -1270,18 +1331,24 @@ static const struct bpf_verifier_ops sk_filter_ops = {
	.convert_ctx_access = sk_filter_convert_ctx_access,		.convert_ctx_access = sk_filter_convert_ctx_access,
	};		};

			static const struct bpf_verifier_ops tc_cls_act_ops = {
			.get_func_proto = tc_cls_act_func_proto,
			.is_valid_access = sk_filter_is_valid_access,
			.convert_ctx_access = sk_filter_convert_ctx_access,
			};

	static struct bpf_prog_type_list sk_filter_type __read_mostly = {		static struct bpf_prog_type_list sk_filter_type __read_mostly = {
	.ops = &sk_filter_ops,		.ops = &sk_filter_ops,
	.type = BPF_PROG_TYPE_SOCKET_FILTER,		.type = BPF_PROG_TYPE_SOCKET_FILTER,
	};		};

	static struct bpf_prog_type_list sched_cls_type __read_mostly = {		static struct bpf_prog_type_list sched_cls_type __read_mostly = {
	.ops = &sk_filter_ops,		.ops = &tc_cls_act_ops,
	.type = BPF_PROG_TYPE_SCHED_CLS,		.type = BPF_PROG_TYPE_SCHED_CLS,
	};		};

	static struct bpf_prog_type_list sched_act_type __read_mostly = {		static struct bpf_prog_type_list sched_act_type __read_mostly = {
	.ops = &sk_filter_ops,		.ops = &tc_cls_act_ops,
	.type = BPF_PROG_TYPE_SCHED_ACT,		.type = BPF_PROG_TYPE_SCHED_ACT,
	};		};

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