Message ID | 20250121012901.87763-12-kerneljasonxing@gmail.com (mailing list archive) |
---|---|
State | Superseded |
Delegated to: | Netdev Maintainers |
Headers | show |
Series | net-timestamp: bpf extension to equip applications transparently | expand |
On 1/20/25 5:28 PM, Jason Xing wrote: > Introduce the callback to correlate tcp_sendmsg timestamp with other > three points (SND/SW/ACK). We can let bpf trace the beginning of > tcp_sendmsg_locked() and fetch the socket addr, so that in > tcp_tx_timestamp() we can correlate the tskey with the socket addr. > It is accurate since they are under the protect of socket lock. > More details can be found in the selftest. > > Signed-off-by: Jason Xing <kerneljasonxing@gmail.com> > --- > include/uapi/linux/bpf.h | 3 +++ > net/ipv4/tcp.c | 1 + > tools/include/uapi/linux/bpf.h | 3 +++ > 3 files changed, 7 insertions(+) > > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h > index 3b9bfc88345c..55c74fa18163 100644 > --- a/include/uapi/linux/bpf.h > +++ b/include/uapi/linux/bpf.h > @@ -7042,6 +7042,9 @@ enum { > * feature is on. It indicates the > * recorded timestamp. > */ > + BPF_SOCK_OPS_TS_TCP_SND_CB, /* Called when every tcp_sendmsg > + * syscall is triggered > + */ I recall we agreed in v5 to adjust the "TCP_" naming part because it will be used in UDP also. Like completely remove the "TCP_" from the name? > }; > > /* List of TCP states. There is a build check in net/ipv4/tcp.c to detect > diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c > index 0a41006b10d1..49e489c346ea 100644 > --- a/net/ipv4/tcp.c > +++ b/net/ipv4/tcp.c > @@ -500,6 +500,7 @@ static void tcp_tx_timestamp(struct sock *sk, struct sockcm_cookie *sockc) > tcb->txstamp_ack_bpf = 1; > shinfo->tx_flags |= SKBTX_BPF; > shinfo->tskey = TCP_SKB_CB(skb)->seq + skb->len - 1; > + bpf_skops_tx_timestamping(sk, skb, BPF_SOCK_OPS_TS_TCP_SND_CB); > } > } > > diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h > index b463aa9c27da..38fc04a7ac20 100644 > --- a/tools/include/uapi/linux/bpf.h > +++ b/tools/include/uapi/linux/bpf.h > @@ -7035,6 +7035,9 @@ enum { > * feature is on. It indicates the > * recorded timestamp. > */ > + BPF_SOCK_OPS_TS_TCP_SND_CB, /* Called when every tcp_sendmsg > + * syscall is triggered > + */ > }; > > /* List of TCP states. There is a build check in net/ipv4/tcp.c to detect
On Sat, Jan 25, 2025 at 8:50 AM Martin KaFai Lau <martin.lau@linux.dev> wrote: > > On 1/20/25 5:28 PM, Jason Xing wrote: > > Introduce the callback to correlate tcp_sendmsg timestamp with other > > three points (SND/SW/ACK). We can let bpf trace the beginning of > > tcp_sendmsg_locked() and fetch the socket addr, so that in > > tcp_tx_timestamp() we can correlate the tskey with the socket addr. > > It is accurate since they are under the protect of socket lock. > > More details can be found in the selftest. > > > > Signed-off-by: Jason Xing <kerneljasonxing@gmail.com> > > --- > > include/uapi/linux/bpf.h | 3 +++ > > net/ipv4/tcp.c | 1 + > > tools/include/uapi/linux/bpf.h | 3 +++ > > 3 files changed, 7 insertions(+) > > > > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h > > index 3b9bfc88345c..55c74fa18163 100644 > > --- a/include/uapi/linux/bpf.h > > +++ b/include/uapi/linux/bpf.h > > @@ -7042,6 +7042,9 @@ enum { > > * feature is on. It indicates the > > * recorded timestamp. > > */ > > + BPF_SOCK_OPS_TS_TCP_SND_CB, /* Called when every tcp_sendmsg > > + * syscall is triggered > > + */ > > I recall we agreed in v5 to adjust the "TCP_" naming part because it will be > used in UDP also. Like completely remove the "TCP_" from the name? Right. The thing is that, after that discussion, I altered my thoughts because I'm not so sure if I need this for UDP (I need more time to think about the UDP case) which can be trace by fentry, sorry. I will follow your instructions to remove "TCP_". Thanks, Jaosn > > > }; > > > > /* List of TCP states. There is a build check in net/ipv4/tcp.c to detect > > diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c > > index 0a41006b10d1..49e489c346ea 100644 > > --- a/net/ipv4/tcp.c > > +++ b/net/ipv4/tcp.c > > @@ -500,6 +500,7 @@ static void tcp_tx_timestamp(struct sock *sk, struct sockcm_cookie *sockc) > > tcb->txstamp_ack_bpf = 1; > > shinfo->tx_flags |= SKBTX_BPF; > > shinfo->tskey = TCP_SKB_CB(skb)->seq + skb->len - 1; > > + bpf_skops_tx_timestamping(sk, skb, BPF_SOCK_OPS_TS_TCP_SND_CB); > > } > > } > > > > diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h > > index b463aa9c27da..38fc04a7ac20 100644 > > --- a/tools/include/uapi/linux/bpf.h > > +++ b/tools/include/uapi/linux/bpf.h > > @@ -7035,6 +7035,9 @@ enum { > > * feature is on. It indicates the > > * recorded timestamp. > > */ > > + BPF_SOCK_OPS_TS_TCP_SND_CB, /* Called when every tcp_sendmsg > > + * syscall is triggered > > + */ > > }; > > > > /* List of TCP states. There is a build check in net/ipv4/tcp.c to detect >
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 3b9bfc88345c..55c74fa18163 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -7042,6 +7042,9 @@ enum { * feature is on. It indicates the * recorded timestamp. */ + BPF_SOCK_OPS_TS_TCP_SND_CB, /* Called when every tcp_sendmsg + * syscall is triggered + */ }; /* List of TCP states. There is a build check in net/ipv4/tcp.c to detect diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 0a41006b10d1..49e489c346ea 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -500,6 +500,7 @@ static void tcp_tx_timestamp(struct sock *sk, struct sockcm_cookie *sockc) tcb->txstamp_ack_bpf = 1; shinfo->tx_flags |= SKBTX_BPF; shinfo->tskey = TCP_SKB_CB(skb)->seq + skb->len - 1; + bpf_skops_tx_timestamping(sk, skb, BPF_SOCK_OPS_TS_TCP_SND_CB); } } diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index b463aa9c27da..38fc04a7ac20 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -7035,6 +7035,9 @@ enum { * feature is on. It indicates the * recorded timestamp. */ + BPF_SOCK_OPS_TS_TCP_SND_CB, /* Called when every tcp_sendmsg + * syscall is triggered + */ }; /* List of TCP states. There is a build check in net/ipv4/tcp.c to detect
Introduce the callback to correlate tcp_sendmsg timestamp with other three points (SND/SW/ACK). We can let bpf trace the beginning of tcp_sendmsg_locked() and fetch the socket addr, so that in tcp_tx_timestamp() we can correlate the tskey with the socket addr. It is accurate since they are under the protect of socket lock. More details can be found in the selftest. Signed-off-by: Jason Xing <kerneljasonxing@gmail.com> --- include/uapi/linux/bpf.h | 3 +++ net/ipv4/tcp.c | 1 + tools/include/uapi/linux/bpf.h | 3 +++ 3 files changed, 7 insertions(+)