From 44f0e43037d3a17b043843ba67610ac7c7e37db6 Mon Sep 17 00:00:00 2001 From: Lawrence Brakmo Date: Thu, 25 Jan 2018 16:14:12 -0800 Subject: [PATCH] bpf: Add support for reading sk_state and more Add support for reading many more tcp_sock fields state, same as sk->sk_state rtt_min same as sk->rtt_min.s[0].v (current rtt_min) snd_ssthresh rcv_nxt snd_nxt snd_una mss_cache ecn_flags rate_delivered rate_interval_us packets_out retrans_out total_retrans segs_in data_segs_in segs_out data_segs_out lost_out sacked_out sk_txhash bytes_received (__u64) bytes_acked (__u64) Signed-off-by: Lawrence Brakmo Signed-off-by: Alexei Starovoitov --- include/uapi/linux/bpf.h | 22 ++++++ net/core/filter.c | 143 ++++++++++++++++++++++++++++++++++++--- 2 files changed, 154 insertions(+), 11 deletions(-) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index c8cecf9cf5bd..46520eae37fa 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -979,6 +979,28 @@ struct bpf_sock_ops { __u32 snd_cwnd; __u32 srtt_us; /* Averaged RTT << 3 in usecs */ __u32 bpf_sock_ops_cb_flags; /* flags defined in uapi/linux/tcp.h */ + __u32 state; + __u32 rtt_min; + __u32 snd_ssthresh; + __u32 rcv_nxt; + __u32 snd_nxt; + __u32 snd_una; + __u32 mss_cache; + __u32 ecn_flags; + __u32 rate_delivered; + __u32 rate_interval_us; + __u32 packets_out; + __u32 retrans_out; + __u32 total_retrans; + __u32 segs_in; + __u32 data_segs_in; + __u32 segs_out; + __u32 data_segs_out; + __u32 lost_out; + __u32 sacked_out; + __u32 sk_txhash; + __u64 bytes_received; + __u64 bytes_acked; }; /* Definitions for bpf_sock_ops_cb_flags */ diff --git a/net/core/filter.c b/net/core/filter.c index 6936d19ac736..a858ebc4ece4 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -3855,33 +3855,43 @@ void bpf_warn_invalid_xdp_action(u32 act) } EXPORT_SYMBOL_GPL(bpf_warn_invalid_xdp_action); -static bool __is_valid_sock_ops_access(int off, int size) +static bool sock_ops_is_valid_access(int off, int size, + enum bpf_access_type type, + struct bpf_insn_access_aux *info) { + const int size_default = sizeof(__u32); + if (off < 0 || off >= sizeof(struct bpf_sock_ops)) return false; + /* The verifier guarantees that size > 0. */ if (off % size != 0) return false; - if (size != sizeof(__u32)) - return false; - - return true; -} -static bool sock_ops_is_valid_access(int off, int size, - enum bpf_access_type type, - struct bpf_insn_access_aux *info) -{ if (type == BPF_WRITE) { switch (off) { case offsetof(struct bpf_sock_ops, reply): + if (size != size_default) + return false; break; default: return false; } + } else { + switch (off) { + case bpf_ctx_range_till(struct bpf_sock_ops, bytes_received, + bytes_acked): + if (size != sizeof(__u64)) + return false; + break; + default: + if (size != size_default) + return false; + break; + } } - return __is_valid_sock_ops_access(off, size); + return true; } static int sk_skb_prologue(struct bpf_insn *insn_buf, bool direct_write, @@ -4498,6 +4508,32 @@ static u32 sock_ops_convert_ctx_access(enum bpf_access_type type, is_fullsock)); break; + case offsetof(struct bpf_sock_ops, state): + BUILD_BUG_ON(FIELD_SIZEOF(struct sock_common, skc_state) != 1); + + *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF( + struct bpf_sock_ops_kern, sk), + si->dst_reg, si->src_reg, + offsetof(struct bpf_sock_ops_kern, sk)); + *insn++ = BPF_LDX_MEM(BPF_B, si->dst_reg, si->dst_reg, + offsetof(struct sock_common, skc_state)); + break; + + case offsetof(struct bpf_sock_ops, rtt_min): + BUILD_BUG_ON(FIELD_SIZEOF(struct tcp_sock, rtt_min) != + sizeof(struct minmax)); + BUILD_BUG_ON(sizeof(struct minmax) < + sizeof(struct minmax_sample)); + + *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF( + struct bpf_sock_ops_kern, sk), + si->dst_reg, si->src_reg, + offsetof(struct bpf_sock_ops_kern, sk)); + *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->dst_reg, + offsetof(struct tcp_sock, rtt_min) + + FIELD_SIZEOF(struct minmax_sample, t)); + break; + /* Helper macro for adding read access to tcp_sock or sock fields. */ #define SOCK_OPS_GET_FIELD(BPF_FIELD, OBJ_FIELD, OBJ) \ do { \ @@ -4580,6 +4616,91 @@ static u32 sock_ops_convert_ctx_access(enum bpf_access_type type, SOCK_OPS_GET_FIELD(bpf_sock_ops_cb_flags, bpf_sock_ops_cb_flags, struct tcp_sock); break; + + case offsetof(struct bpf_sock_ops, snd_ssthresh): + SOCK_OPS_GET_FIELD(snd_ssthresh, snd_ssthresh, struct tcp_sock); + break; + + case offsetof(struct bpf_sock_ops, rcv_nxt): + SOCK_OPS_GET_FIELD(rcv_nxt, rcv_nxt, struct tcp_sock); + break; + + case offsetof(struct bpf_sock_ops, snd_nxt): + SOCK_OPS_GET_FIELD(snd_nxt, snd_nxt, struct tcp_sock); + break; + + case offsetof(struct bpf_sock_ops, snd_una): + SOCK_OPS_GET_FIELD(snd_una, snd_una, struct tcp_sock); + break; + + case offsetof(struct bpf_sock_ops, mss_cache): + SOCK_OPS_GET_FIELD(mss_cache, mss_cache, struct tcp_sock); + break; + + case offsetof(struct bpf_sock_ops, ecn_flags): + SOCK_OPS_GET_FIELD(ecn_flags, ecn_flags, struct tcp_sock); + break; + + case offsetof(struct bpf_sock_ops, rate_delivered): + SOCK_OPS_GET_FIELD(rate_delivered, rate_delivered, + struct tcp_sock); + break; + + case offsetof(struct bpf_sock_ops, rate_interval_us): + SOCK_OPS_GET_FIELD(rate_interval_us, rate_interval_us, + struct tcp_sock); + break; + + case offsetof(struct bpf_sock_ops, packets_out): + SOCK_OPS_GET_FIELD(packets_out, packets_out, struct tcp_sock); + break; + + case offsetof(struct bpf_sock_ops, retrans_out): + SOCK_OPS_GET_FIELD(retrans_out, retrans_out, struct tcp_sock); + break; + + case offsetof(struct bpf_sock_ops, total_retrans): + SOCK_OPS_GET_FIELD(total_retrans, total_retrans, + struct tcp_sock); + break; + + case offsetof(struct bpf_sock_ops, segs_in): + SOCK_OPS_GET_FIELD(segs_in, segs_in, struct tcp_sock); + break; + + case offsetof(struct bpf_sock_ops, data_segs_in): + SOCK_OPS_GET_FIELD(data_segs_in, data_segs_in, struct tcp_sock); + break; + + case offsetof(struct bpf_sock_ops, segs_out): + SOCK_OPS_GET_FIELD(segs_out, segs_out, struct tcp_sock); + break; + + case offsetof(struct bpf_sock_ops, data_segs_out): + SOCK_OPS_GET_FIELD(data_segs_out, data_segs_out, + struct tcp_sock); + break; + + case offsetof(struct bpf_sock_ops, lost_out): + SOCK_OPS_GET_FIELD(lost_out, lost_out, struct tcp_sock); + break; + + case offsetof(struct bpf_sock_ops, sacked_out): + SOCK_OPS_GET_FIELD(sacked_out, sacked_out, struct tcp_sock); + break; + + case offsetof(struct bpf_sock_ops, sk_txhash): + SOCK_OPS_GET_FIELD(sk_txhash, sk_txhash, struct sock); + break; + + case offsetof(struct bpf_sock_ops, bytes_received): + SOCK_OPS_GET_FIELD(bytes_received, bytes_received, + struct tcp_sock); + break; + + case offsetof(struct bpf_sock_ops, bytes_acked): + SOCK_OPS_GET_FIELD(bytes_acked, bytes_acked, struct tcp_sock); + break; } return insn - insn_buf; } -- 2.30.2