diff options
| author |   Jason Xing <kerneljasonxing@gmail.com> | 2025-02-20 15:29:39 +0800 |
|---|---|---|
| committer |   Martin KaFai Lau <martin.lau@kernel.org> | 2025-02-20 14:30:02 -0800 |
| commit | 59422464266f8baa091edcb3779f0955a21abf00 (patch) | |
| tree | 4b244bd463f9919f319ebea4927093f148759124 /net | |
| parent | bpf: Add BPF_SOCK_OPS_TSTAMP_SENDMSG_CB callback (diff) | |
| download | wireguard-linux-59422464266f8baa091edcb3779f0955a21abf00.tar.xz wireguard-linux-59422464266f8baa091edcb3779f0955a21abf00.zip | |
bpf: Support selective sampling for bpf timestamping
Add the bpf_sock_ops_enable_tx_tstamp kfunc to allow BPF programs to
selectively enable TX timestamping on a skb during tcp_sendmsg().
For example, BPF program will limit tracking X numbers of packets
and then will stop there instead of tracing all the sendmsgs of
matched flow all along. It would be helpful for users who cannot
afford to calculate latencies from every sendmsg call probably
due to the performance or storage space consideration.
Signed-off-by: Jason Xing <kerneljasonxing@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250220072940.99994-12-kerneljasonxing@gmail.com
Diffstat (limited to 'net')
| -rw-r--r-- | net/core/filter.c | 31 |
1 files changed, 30 insertions, 1 deletions
diff --git a/net/core/filter.c b/net/core/filter.c index 90a8fbc2e096..a0867c5b32b3 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -12103,6 +12103,25 @@ __bpf_kfunc int bpf_sk_assign_tcp_reqsk(struct __sk_buff *s, struct sock *sk, #endif } +__bpf_kfunc int bpf_sock_ops_enable_tx_tstamp(struct bpf_sock_ops_kern *skops, + u64 flags) +{ + struct sk_buff *skb; + + if (skops->op != BPF_SOCK_OPS_TSTAMP_SENDMSG_CB) + return -EOPNOTSUPP; + + if (flags) + return -EINVAL; + + skb = skops->skb; + skb_shinfo(skb)->tx_flags |= SKBTX_BPF; + TCP_SKB_CB(skb)->txstamp_ack |= TSTAMP_ACK_BPF; + skb_shinfo(skb)->tskey = TCP_SKB_CB(skb)->seq + skb->len - 1; + + return 0; +} + __bpf_kfunc_end_defs(); int bpf_dynptr_from_skb_rdonly(struct __sk_buff *skb, u64 flags, @@ -12136,6 +12155,10 @@ BTF_KFUNCS_START(bpf_kfunc_check_set_tcp_reqsk) BTF_ID_FLAGS(func, bpf_sk_assign_tcp_reqsk, KF_TRUSTED_ARGS) BTF_KFUNCS_END(bpf_kfunc_check_set_tcp_reqsk) +BTF_KFUNCS_START(bpf_kfunc_check_set_sock_ops) +BTF_ID_FLAGS(func, bpf_sock_ops_enable_tx_tstamp, KF_TRUSTED_ARGS) +BTF_KFUNCS_END(bpf_kfunc_check_set_sock_ops) + static const struct btf_kfunc_id_set bpf_kfunc_set_skb = { .owner = THIS_MODULE, .set = &bpf_kfunc_check_set_skb, @@ -12156,6 +12179,11 @@ static const struct btf_kfunc_id_set bpf_kfunc_set_tcp_reqsk = { .set = &bpf_kfunc_check_set_tcp_reqsk, }; +static const struct btf_kfunc_id_set bpf_kfunc_set_sock_ops = { + .owner = THIS_MODULE, + .set = &bpf_kfunc_check_set_sock_ops, +}; + static int __init bpf_kfunc_init(void) { int ret; @@ -12174,7 +12202,8 @@ static int __init bpf_kfunc_init(void) ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_XDP, &bpf_kfunc_set_xdp); ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_CGROUP_SOCK_ADDR, &bpf_kfunc_set_sock_addr); - return ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS, &bpf_kfunc_set_tcp_reqsk); + ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS, &bpf_kfunc_set_tcp_reqsk); + return ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SOCK_OPS, &bpf_kfunc_set_sock_ops); } late_initcall(bpf_kfunc_init); |