diff options
| author | Jason Xing <[email protected]> | 2025-02-20 07:29:38 +0000 |
|---|---|---|
| committer | Martin KaFai Lau <[email protected]> | 2025-02-20 22:29:48 +0000 |
| commit | c9525d240c8117de35171ae705058ddf9667be27 (patch) | |
| tree | 6dc65b46fda900064c633445963488eadb803d76 /net/ipv4/tcp.c | |
| parent | bpf: Add BPF_SOCK_OPS_TSTAMP_ACK_CB callback (diff) | |
| download | kernel-c9525d240c8117de35171ae705058ddf9667be27.tar.gz kernel-c9525d240c8117de35171ae705058ddf9667be27.zip | |
bpf: Add BPF_SOCK_OPS_TSTAMP_SENDMSG_CB callback
This patch introduces a new callback in tcp_tx_timestamp() to correlate
tcp_sendmsg timestamp with timestamps from other tx timestamping
callbacks (e.g., SND/SW/ACK).
Without this patch, BPF program wouldn't know which timestamps belong
to which flow because of no socket lock protection. This new callback
is inserted in tcp_tx_timestamp() to address this issue because
tcp_tx_timestamp() still owns the same socket lock with
tcp_sendmsg_locked() in the meanwhile tcp_tx_timestamp() initializes
the timestamping related fields for the skb, especially tskey. The
tskey is the bridge to do the correlation.
For TCP, BPF program hooks the beginning of tcp_sendmsg_locked() and
then stores the sendmsg timestamp at the bpf_sk_storage, correlating
this timestamp with its tskey that are later used in other sending
timestamping callbacks.
Signed-off-by: Jason Xing <[email protected]>
Signed-off-by: Martin KaFai Lau <[email protected]>
Reviewed-by: Willem de Bruijn <[email protected]>
Link: https://patch.msgid.link/[email protected]
Diffstat (limited to 'net/ipv4/tcp.c')
| -rw-r--r-- | net/ipv4/tcp.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 2171e2f045bb..298d1da05bee 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -496,6 +496,10 @@ static void tcp_tx_timestamp(struct sock *sk, struct sockcm_cookie *sockc) if (tsflags & SOF_TIMESTAMPING_TX_RECORD_MASK) shinfo->tskey = TCP_SKB_CB(skb)->seq + skb->len - 1; } + + if (cgroup_bpf_enabled(CGROUP_SOCK_OPS) && + SK_BPF_CB_FLAG_TEST(sk, SK_BPF_CB_TX_TIMESTAMPING) && skb) + bpf_skops_tx_timestamping(sk, skb, BPF_SOCK_OPS_TSTAMP_SENDMSG_CB); } static bool tcp_stream_is_readable(struct sock *sk, int target) |