Commit bf976514 authored by Mat Martineau's avatar Mat Martineau Committed by David S. Miller
Browse files

sock: Make sk_protocol a 16-bit value 



Match the 16-bit width of skbuff->protocol. Fills an 8-bit hole so
sizeof(struct sock) does not change.

Also take care of BPF field access for sk_type/sk_protocol. Both of them
are now outside the bitfield, so we can use load instructions without
further shifting/masking.

v5 -> v6:
 - update eBPF accessors, too (Intel's kbuild test robot)
v2 -> v3:
 - keep 'sk_type' 2 bytes aligned (Eric)
v1 -> v2:
 - preserve sk_pacing_shift as bit field (Eric)

Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: bpf@vger.kernel.org
Co-developed-by: default avatarPaolo Abeni <pabeni@redhat.com>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
Co-developed-by: default avatarMatthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: default avatarMatthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: default avatarMat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent e9cdced7

include/net/sock.h

+5 −20
Original line number Diff line number Diff line
@@ -436,30 +436,15 @@ struct sock { 
	 * Because of non atomicity rules, all

	 * changes are protected by socket lock.

	 */

	unsigned int		__sk_flags_offset[0];

#ifdef __BIG_ENDIAN_BITFIELD

#define SK_FL_PROTO_SHIFT  16

#define SK_FL_PROTO_MASK   0x00ff0000



#define SK_FL_TYPE_SHIFT   0

#define SK_FL_TYPE_MASK    0x0000ffff

#else

#define SK_FL_PROTO_SHIFT  8

#define SK_FL_PROTO_MASK   0x0000ff00



#define SK_FL_TYPE_SHIFT   16

#define SK_FL_TYPE_MASK    0xffff0000

#endif



	unsigned int		sk_padding : 1,

	u8			sk_padding : 1,

				sk_kern_sock : 1,

				sk_no_check_tx : 1,

				sk_no_check_rx : 1,

				sk_userlocks : 4,

				sk_protocol  : 8,

				sk_type      : 16;

	u16			sk_gso_max_segs;

				sk_userlocks : 4;

	u8			sk_pacing_shift;

	u16			sk_type;

	u16			sk_protocol;

	u16			sk_gso_max_segs;

	unsigned long	        sk_lingertime;

	struct proto		*sk_prot_creator;

	rwlock_t		sk_callback_lock;

include/trace/events/sock.h

+1 −1
Original line number Diff line number Diff line
@@ -147,7 +147,7 @@ TRACE_EVENT(inet_sock_set_state, 
		__field(__u16, sport)

		__field(__u16, dport)

		__field(__u16, family)

		__field(__u8, protocol)

		__field(__u16, protocol)

		__array(__u8, saddr, 4)

		__array(__u8, daddr, 4)

		__array(__u8, saddr_v6, 16)

net/core/filter.c

+22 −38
Original line number Diff line number Diff line
@@ -7607,21 +7607,21 @@ u32 bpf_sock_convert_ctx_access(enum bpf_access_type type, 
		break;



	case offsetof(struct bpf_sock, type):

		BUILD_BUG_ON(HWEIGHT32(SK_FL_TYPE_MASK) != BITS_PER_BYTE * 2);

		*insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->src_reg,

				      offsetof(struct sock, __sk_flags_offset));

		*insn++ = BPF_ALU32_IMM(BPF_AND, si->dst_reg, SK_FL_TYPE_MASK);

		*insn++ = BPF_ALU32_IMM(BPF_RSH, si->dst_reg, SK_FL_TYPE_SHIFT);

		*target_size = 2;

		*insn++ = BPF_LDX_MEM(

			BPF_FIELD_SIZEOF(struct sock, sk_type),

			si->dst_reg, si->src_reg,

			bpf_target_off(struct sock, sk_type,

				       sizeof_field(struct sock, sk_type),

				       target_size));

		break;



	case offsetof(struct bpf_sock, protocol):

		BUILD_BUG_ON(HWEIGHT32(SK_FL_PROTO_MASK) != BITS_PER_BYTE);

		*insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->src_reg,

				      offsetof(struct sock, __sk_flags_offset));

		*insn++ = BPF_ALU32_IMM(BPF_AND, si->dst_reg, SK_FL_PROTO_MASK);

		*insn++ = BPF_ALU32_IMM(BPF_RSH, si->dst_reg, SK_FL_PROTO_SHIFT);

		*target_size = 1;

		*insn++ = BPF_LDX_MEM(

			BPF_FIELD_SIZEOF(struct sock, sk_protocol),

			si->dst_reg, si->src_reg,

			bpf_target_off(struct sock, sk_protocol,

				       sizeof_field(struct sock, sk_protocol),

				       target_size));

		break;



	case offsetof(struct bpf_sock, src_ip4):
@@ -7903,20 +7903,13 @@ static u32 sock_addr_convert_ctx_access(enum bpf_access_type type, 
		break;



	case offsetof(struct bpf_sock_addr, type):

		SOCK_ADDR_LOAD_NESTED_FIELD_SIZE_OFF(

			struct bpf_sock_addr_kern, struct sock, sk,

			__sk_flags_offset, BPF_W, 0);

		*insn++ = BPF_ALU32_IMM(BPF_AND, si->dst_reg, SK_FL_TYPE_MASK);

		*insn++ = BPF_ALU32_IMM(BPF_RSH, si->dst_reg, SK_FL_TYPE_SHIFT);

		SOCK_ADDR_LOAD_NESTED_FIELD(struct bpf_sock_addr_kern,

					    struct sock, sk, sk_type);

		break;



	case offsetof(struct bpf_sock_addr, protocol):

		SOCK_ADDR_LOAD_NESTED_FIELD_SIZE_OFF(

			struct bpf_sock_addr_kern, struct sock, sk,

			__sk_flags_offset, BPF_W, 0);

		*insn++ = BPF_ALU32_IMM(BPF_AND, si->dst_reg, SK_FL_PROTO_MASK);

		*insn++ = BPF_ALU32_IMM(BPF_RSH, si->dst_reg,

					SK_FL_PROTO_SHIFT);

		SOCK_ADDR_LOAD_NESTED_FIELD(struct bpf_sock_addr_kern,

					    struct sock, sk, sk_protocol);

		break;



	case offsetof(struct bpf_sock_addr, msg_src_ip4):
@@ -8835,11 +8828,11 @@ sk_reuseport_is_valid_access(int off, int size, 
				    skb,				\

				    SKB_FIELD)



#define SK_REUSEPORT_LOAD_SK_FIELD_SIZE_OFF(SK_FIELD, BPF_SIZE, EXTRA_OFF) \

	SOCK_ADDR_LOAD_NESTED_FIELD_SIZE_OFF(struct sk_reuseport_kern,	\

#define SK_REUSEPORT_LOAD_SK_FIELD(SK_FIELD)				\

	SOCK_ADDR_LOAD_NESTED_FIELD(struct sk_reuseport_kern,		\

				    struct sock,			\

				    sk,					\

					     SK_FIELD, BPF_SIZE, EXTRA_OFF)

				    SK_FIELD)



static u32 sk_reuseport_convert_ctx_access(enum bpf_access_type type,

					   const struct bpf_insn *si,
@@ -8863,16 +8856,7 @@ static u32 sk_reuseport_convert_ctx_access(enum bpf_access_type type, 
		break;



	case offsetof(struct sk_reuseport_md, ip_protocol):

		BUILD_BUG_ON(HWEIGHT32(SK_FL_PROTO_MASK) != BITS_PER_BYTE);

		SK_REUSEPORT_LOAD_SK_FIELD_SIZE_OFF(__sk_flags_offset,

						    BPF_W, 0);

		*insn++ = BPF_ALU32_IMM(BPF_AND, si->dst_reg, SK_FL_PROTO_MASK);

		*insn++ = BPF_ALU32_IMM(BPF_RSH, si->dst_reg,

					SK_FL_PROTO_SHIFT);

		/* SK_FL_PROTO_MASK and SK_FL_PROTO_SHIFT are endian

		 * aware.  No further narrowing or masking is needed.

		 */

		*target_size = 1;

		SK_REUSEPORT_LOAD_SK_FIELD(sk_protocol);

		break;



	case offsetof(struct sk_reuseport_md, data_end):

CRA Git | Maintained and supported by SUSTech CRA and CCSE