From bf9765145b856fa2e238a5b8a54453795ba30ad6 Mon Sep 17 00:00:00 2001 From: Mat Martineau Date: Thu, 9 Jan 2020 07:59:15 -0800 Subject: 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 Cc: Daniel Borkmann Cc: bpf@vger.kernel.org Co-developed-by: Paolo Abeni Signed-off-by: Paolo Abeni Co-developed-by: Matthieu Baerts Signed-off-by: Matthieu Baerts Signed-off-by: Mat Martineau Signed-off-by: David S. Miller --- include/net/sock.h | 25 ++++--------------- include/trace/events/sock.h | 2 +- net/core/filter.c | 60 +++++++++++++++++---------------------------- 3 files changed, 28 insertions(+), 59 deletions(-) diff --git a/include/net/sock.h b/include/net/sock.h index 091e55428415..8766f9bc3e70 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -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; diff --git a/include/trace/events/sock.h b/include/trace/events/sock.h index 51fe9f6719eb..3ff12b90048d 100644 --- a/include/trace/events/sock.h +++ b/include/trace/events/sock.h @@ -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) diff --git a/net/core/filter.c b/net/core/filter.c index 42fd17c48c5f..ef01c5599501 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -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, \ - struct sock, \ - sk, \ - SK_FIELD, BPF_SIZE, EXTRA_OFF) +#define SK_REUSEPORT_LOAD_SK_FIELD(SK_FIELD) \ + SOCK_ADDR_LOAD_NESTED_FIELD(struct sk_reuseport_kern, \ + struct sock, \ + sk, \ + 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): -- cgit v1.2.3-59-g8ed1b