From 655a51e536c09d15ffa3603b1b6fce2b45b85a1f Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Sat, 9 Feb 2019 23:22:24 -0800 Subject: bpf: Add struct bpf_tcp_sock and BPF_FUNC_tcp_sock This patch adds a helper function BPF_FUNC_tcp_sock and it is currently available for cg_skb and sched_(cls|act): struct bpf_tcp_sock *bpf_tcp_sock(struct bpf_sock *sk); int cg_skb_foo(struct __sk_buff *skb) { struct bpf_tcp_sock *tp; struct bpf_sock *sk; __u32 snd_cwnd; sk = skb->sk; if (!sk) return 1; tp = bpf_tcp_sock(sk); if (!tp) return 1; snd_cwnd = tp->snd_cwnd; /* ... */ return 1; } A 'struct bpf_tcp_sock' is also added to the uapi bpf.h to provide read-only access. bpf_tcp_sock has all the existing tcp_sock's fields that has already been exposed by the bpf_sock_ops. i.e. no new tcp_sock's fields are exposed in bpf.h. This helper returns a pointer to the tcp_sock. If it is not a tcp_sock or it cannot be traced back to a tcp_sock by sk_to_full_sk(), it returns NULL. Hence, the caller needs to check for NULL before accessing it. The current use case is to expose members from tcp_sock to allow a cg_skb_bpf_prog to provide per cgroup traffic policing/shaping. Acked-by: Alexei Starovoitov Signed-off-by: Martin KaFai Lau Signed-off-by: Alexei Starovoitov --- include/uapi/linux/bpf.h | 51 +++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 50 insertions(+), 1 deletion(-) (limited to 'include/uapi/linux/bpf.h') diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index d8f91777c5b6..25c8c0e62ecf 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -2337,6 +2337,15 @@ union bpf_attr { * Return * A **struct bpf_sock** pointer on success, or NULL in * case of failure. + * + * struct bpf_tcp_sock *bpf_tcp_sock(struct bpf_sock *sk) + * Description + * This helper gets a **struct bpf_tcp_sock** pointer from a + * **struct bpf_sock** pointer. + * + * Return + * A **struct bpf_tcp_sock** pointer on success, or NULL in + * case of failure. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -2434,7 +2443,8 @@ union bpf_attr { FN(rc_pointer_rel), \ FN(spin_lock), \ FN(spin_unlock), \ - FN(sk_fullsock), + FN(sk_fullsock), \ + FN(tcp_sock), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call @@ -2616,6 +2626,45 @@ struct bpf_sock { __u32 state; }; +struct bpf_tcp_sock { + __u32 snd_cwnd; /* Sending congestion window */ + __u32 srtt_us; /* smoothed round trip time << 3 in usecs */ + __u32 rtt_min; + __u32 snd_ssthresh; /* Slow start size threshold */ + __u32 rcv_nxt; /* What we want to receive next */ + __u32 snd_nxt; /* Next sequence we send */ + __u32 snd_una; /* First byte we want an ack for */ + __u32 mss_cache; /* Cached effective mss, not including SACKS */ + __u32 ecn_flags; /* ECN status bits. */ + __u32 rate_delivered; /* saved rate sample: packets delivered */ + __u32 rate_interval_us; /* saved rate sample: time elapsed */ + __u32 packets_out; /* Packets which are "in flight" */ + __u32 retrans_out; /* Retransmitted packets out */ + __u32 total_retrans; /* Total retransmits for entire connection */ + __u32 segs_in; /* RFC4898 tcpEStatsPerfSegsIn + * total number of segments in. + */ + __u32 data_segs_in; /* RFC4898 tcpEStatsPerfDataSegsIn + * total number of data segments in. + */ + __u32 segs_out; /* RFC4898 tcpEStatsPerfSegsOut + * The total number of segments sent. + */ + __u32 data_segs_out; /* RFC4898 tcpEStatsPerfDataSegsOut + * total number of data segments sent. + */ + __u32 lost_out; /* Lost packets */ + __u32 sacked_out; /* SACK'd packets */ + __u64 bytes_received; /* RFC4898 tcpEStatsAppHCThruOctetsReceived + * sum(delta(rcv_nxt)), or how many bytes + * were acked. + */ + __u64 bytes_acked; /* RFC4898 tcpEStatsAppHCThruOctetsAcked + * sum(delta(snd_una)), or how many bytes + * were acked. + */ +}; + struct bpf_sock_tuple { union { struct { -- cgit v1.2.3-55-g7522