On Fri, Dec 13, 2024 at 7:26 AM Martin KaFai Lau <martin.lau@xxxxxxxxx> wrote: > > On 12/7/24 9:37 AM, Jason Xing wrote: > > From: Jason Xing <kernelxing@xxxxxxxxxxx> > > > > Passing the hwtstamp to bpf prog which can print. > > > > Signed-off-by: Jason Xing <kernelxing@xxxxxxxxxxx> > > --- > > include/net/sock.h | 6 ++++-- > > net/core/skbuff.c | 17 +++++++++++++---- > > net/core/sock.c | 4 +++- > > 3 files changed, 20 insertions(+), 7 deletions(-) > > > > diff --git a/include/net/sock.h b/include/net/sock.h > > index f88a00108a2f..9bc883573208 100644 > > --- a/include/net/sock.h > > +++ b/include/net/sock.h > > @@ -2921,9 +2921,11 @@ int sock_set_timestamping(struct sock *sk, int optname, > > > > void sock_enable_timestamps(struct sock *sk); > > #if defined(CONFIG_CGROUP_BPF) && defined(CONFIG_BPF_SYSCALL) > > -void bpf_skops_tx_timestamping(struct sock *sk, struct sk_buff *skb, int op); > > +void bpf_skops_tx_timestamping(struct sock *sk, struct sk_buff *skb, int op, > > + u32 nargs, u32 *args); > > #else > > -static inline void bpf_skops_tx_timestamping(struct sock *sk, struct sk_buff *skb, int op) > > +static inline void bpf_skops_tx_timestamping(struct sock *sk, struct sk_buff *skb, int op, > > + u32 nargs, u32 *args) > > { > > } > > #endif > > diff --git a/net/core/skbuff.c b/net/core/skbuff.c > > index 48b0c71e9522..182a44815630 100644 > > --- a/net/core/skbuff.c > > +++ b/net/core/skbuff.c > > @@ -5539,8 +5539,12 @@ void skb_complete_tx_timestamp(struct sk_buff *skb, > > } > > EXPORT_SYMBOL_GPL(skb_complete_tx_timestamp); > > > > -static void __skb_tstamp_tx_bpf(struct sock *sk, struct sk_buff *skb, int tstype) > > +static void __skb_tstamp_tx_bpf(struct sock *sk, struct sk_buff *skb, > > + struct skb_shared_hwtstamps *hwtstamps, > > + int tstype) > > { > > + struct timespec64 tstamp; > > + u32 args[2] = {0, 0}; > > int op; > > > > if (!sk) > > @@ -5552,6 +5556,11 @@ static void __skb_tstamp_tx_bpf(struct sock *sk, struct sk_buff *skb, int tstype > > break; > > case SCM_TSTAMP_SND: > > op = BPF_SOCK_OPS_TS_SW_OPT_CB; > > > + if (hwtstamps) { > > + tstamp = ktime_to_timespec64(hwtstamps->hwtstamp); > > Avoid this conversion which is likely not useful to the bpf prog. Directly pass > hwtstamps->hwtstamp (in ns?) to the bpf prog. Put lower 32bits in args[0] and > higher 32bits in args[1]. It makes sense. > > Also, how about adding a BPF_SOCK_OPS_TS_"HW"_OPT_CB for the "hwtstamps != NULL" > case instead of reusing the BPF_SOCK_OPS_TS_"SW"_OPT_CB? Good suggestion. Will do that. > > A more subtle thing for the hwtstamps case is, afaik the bpf prog will not be > called. All drivers are still only testing SKBTX_HW_TSTAMP instead of testing > (SKBTX_HW_TSTAMP | SKBTX_BPF). Ah, I didn't realize that!! > > There are a lot of drivers to change though. A quick thought is to rename the > existing SKBTX_HW_TSTAMP (e.g. __SKBTX_HW_TSTAMP = 1 << 0) and define > SKBTX_HW_TSTAMP like: > > #define SKBTX_HW_TSTAMP (__SKBTX_HW_TSTAMP | SKBTX_BPF) I will take it, thanks! > > Then change some of the existing skb_shinfo(skb)->tx_flags "setting" site to use > __SKBTX_HW_TSTAMP instead. e.g. in __sock_tx_timestamp(). Not very pretty but > may be still better than changing many drivers. May be there is a better way... I agree with your approach. Changing so many drivers would be a head-ache thing. > > While talking about where to test the SKBTX_BPF bit, I wonder if the new > skb_tstamp_is_set() is needed. For the non SKBTX_HW_TSTAMP case, the number of > tx_flags testing sites should be limited, so should be easy to add the SKBTX_BPF > bit test. e.g. at the __dev_queue_xmit, test "if > (unlikely(skb_shinfo(skb)->tx_flags & (SKBTX_SCHED_TSTAMP | SKBTX_BPF)))". Patch > 6 has also tested the bpf specific bit at tcp_ack_tstamp() before calling the > __skb_tstamp_tx(). > > At the beginning of __skb_tstamp_tx(), do something like this: > > void __skb_tstamp_tx(struct sk_buff *orig_skb, > const struct sk_buff *ack_skb, > struct skb_shared_hwtstamps *hwtstamps, > struct sock *sk, int tstype) > { > if (cgroup_bpf_enabled(CGROUP_SOCK_OPS) && > unlikely(skb_shinfo(skb)->tx_flags & SKBTX_BPF)) > __skb_tstamp_tx_bpf(sk, orig_skb, hwtstamps, tstype); > > if (unlikely(!(skb_shinfo(skb)->tx_flags & ~SKBTX_BPF))) > return; > > Then the new skb_tstamp_tx_output() shuffle is probably not be needed also. > > > + args[0] = tstamp.tv_sec; > > + args[1] = tstamp.tv_nsec; > > + } > > break; > > case SCM_TSTAMP_ACK: > > op = BPF_SOCK_OPS_TS_ACK_OPT_CB; > > @@ -5560,7 +5569,7 @@ static void __skb_tstamp_tx_bpf(struct sock *sk, struct sk_buff *skb, int tstype > > return; > > } > > > > - bpf_skops_tx_timestamping(sk, skb, op); > > + bpf_skops_tx_timestamping(sk, skb, op, 2, args); > > } > > > > static void skb_tstamp_tx_output(struct sk_buff *orig_skb, > > @@ -5651,7 +5660,7 @@ void __skb_tstamp_tx(struct sk_buff *orig_skb, > > if (unlikely(skb_tstamp_is_set(orig_skb, tstype, false))) > > skb_tstamp_tx_output(orig_skb, ack_skb, hwtstamps, sk, tstype); > > if (unlikely(skb_tstamp_is_set(orig_skb, tstype, true))) > > - __skb_tstamp_tx_bpf(sk, orig_skb, tstype); > > + __skb_tstamp_tx_bpf(sk, orig_skb, hwtstamps, tstype); > > } > > EXPORT_SYMBOL_GPL(__skb_tstamp_tx); > > > > @@ -5662,7 +5671,7 @@ void skb_tstamp_tx(struct sk_buff *orig_skb, > > > > skb_tstamp_tx_output(orig_skb, NULL, hwtstamps, orig_skb->sk, tstype); > > if (unlikely(skb_tstamp_is_set(orig_skb, tstype, true))) > > - __skb_tstamp_tx_bpf(orig_skb->sk, orig_skb, tstype); > > + __skb_tstamp_tx_bpf(orig_skb->sk, orig_skb, hwtstamps, tstype); > > } > > EXPORT_SYMBOL_GPL(skb_tstamp_tx); > > > > diff --git a/net/core/sock.c b/net/core/sock.c > > index 79cb5c74c76c..504939bafe0c 100644 > > --- a/net/core/sock.c > > +++ b/net/core/sock.c > > @@ -942,7 +942,8 @@ int sock_set_timestamping(struct sock *sk, int optname, > > } > > > > #if defined(CONFIG_CGROUP_BPF) && defined(CONFIG_BPF_SYSCALL) > > -void bpf_skops_tx_timestamping(struct sock *sk, struct sk_buff *skb, int op) > > +void bpf_skops_tx_timestamping(struct sock *sk, struct sk_buff *skb, int op, > > + u32 nargs, u32 *args) > > Directly pass hwtstamps->hwtstamp instead of args and nargs. Save a memcpy below. > > > { > > struct bpf_sock_ops_kern sock_ops; > > > > @@ -952,6 +953,7 @@ void bpf_skops_tx_timestamping(struct sock *sk, struct sk_buff *skb, int op) > > sock_ops.op = op; > > sock_ops.is_fullsock = 1; > > sock_ops.sk = sk; > > + memcpy(sock_ops.args, args, nargs * sizeof(*args)); > > __cgroup_bpf_run_filter_sock_ops(sk, &sock_ops, CGROUP_SOCK_OPS); > > } > > #endif >