| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <c992e03b-eee5-471a-9002-f35bdfa1be2d@quicinc.com>
Date: Mon, 15 Apr 2024 13:27:56 -0700
From: "Abhishek Chauhan (ABC)" <quic_abchauha@...cinc.com>
To: Willem de Bruijn <willemdebruijn.kernel@...il.com>,
"David S. Miller"
<davem@...emloft.net>,
Eric Dumazet <edumazet@...gle.com>, Jakub Kicinski
<kuba@...nel.org>,
Paolo Abeni <pabeni@...hat.com>, <netdev@...r.kernel.org>,
<linux-kernel@...r.kernel.org>, Andrew Halaney <ahalaney@...hat.com>,
"Martin
KaFai Lau" <martin.lau@...nel.org>,
Martin KaFai Lau <martin.lau@...ux.dev>,
Daniel Borkmann <daniel@...earbox.net>, bpf <bpf@...r.kernel.org>
CC: <kernel@...cinc.com>
Subject: Re: [RFC PATCH bpf-next v3 1/2] net: Rename mono_delivery_time to
tstamp_type for scalabilty
On 4/13/2024 11:54 AM, Willem de Bruijn wrote:
> Abhishek Chauhan wrote:
>> mono_delivery_time was added to check if skb->tstamp has delivery
>> time in mono clock base (i.e. EDT) otherwise skb->tstamp has
>> timestamp in ingress and delivery_time at egress.
>>
>> Renaming the bitfield from mono_delivery_time to tstamp_type is for
>> extensibilty for other timestamps such as userspace timestamp
>> (i.e. SO_TXTIME) set via sock opts.
>>
>> As we are renaming the mono_delivery_time to tstamp_type, it makes
>> sense to start assigning tstamp_type based out if enum defined as
>> part of this commit
>>
>> Earlier we used bool arg flag to check if the tstamp is mono in
>> function skb_set_delivery_time, Now the signature of the functions
>> accepts enum to distinguish between mono and real time
>>
>> Bridge driver today has no support to forward the userspace timestamp
>> packets and ends up resetting the timestamp. ETF qdisc checks the
>> packet coming from userspace and encounters to be 0 thereby dropping
>> time sensitive packets. These changes will allow userspace timestamps
>> packets to be forwarded from the bridge to NIC drivers.
>>
>> In future tstamp_type:1 can be extended to support userspace timestamp
>> by increasing the bitfield.
>>
>> Link: https://lore.kernel.org/netdev/bc037db4-58bb-4861-ac31-a361a93841d3@linux.dev/
>> Signed-off-by: Abhishek Chauhan <quic_abchauha@...cinc.com>
>> ---
>> Changes since v2
>> - Minor changes to commit subject
>>
>> Changes since v1
>> - Squashed the two commits into one as mentioned by Willem.
>> - Introduced switch in skb_set_delivery_time.
>> - Renamed and removed directionality aspects w.r.t tstamp_type
>> as mentioned by Willem.
>>
>> include/linux/skbuff.h | 33 +++++++++++++++-------
>> include/net/inet_frag.h | 4 +--
>> net/bridge/netfilter/nf_conntrack_bridge.c | 6 ++--
>> net/core/dev.c | 2 +-
>> net/core/filter.c | 8 +++---
>> net/ipv4/inet_fragment.c | 2 +-
>> net/ipv4/ip_fragment.c | 2 +-
>> net/ipv4/ip_output.c | 8 +++---
>> net/ipv4/tcp_output.c | 14 ++++-----
>> net/ipv6/ip6_output.c | 6 ++--
>> net/ipv6/netfilter.c | 6 ++--
>> net/ipv6/netfilter/nf_conntrack_reasm.c | 2 +-
>> net/ipv6/reassembly.c | 2 +-
>> net/ipv6/tcp_ipv6.c | 2 +-
>> net/sched/act_bpf.c | 4 +--
>> net/sched/cls_bpf.c | 4 +--
>> 16 files changed, 59 insertions(+), 46 deletions(-)
>>
>> diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
>> index 7135a3e94afd..a83a2120b57f 100644
>> --- a/include/linux/skbuff.h
>> +++ b/include/linux/skbuff.h
>> @@ -702,6 +702,11 @@ typedef unsigned int sk_buff_data_t;
>> typedef unsigned char *sk_buff_data_t;
>> #endif
>>
>> +enum skb_tstamp_type {
>> + CLOCK_REAL = 0, /* Time base is realtime */
>> + CLOCK_MONO = 1, /* Time base is Monotonic */
>> +};
>
> Minor: inconsistent capitalization
>
I will fix this.
>> +
>> /**
>> * DOC: Basic sk_buff geometry
>> *
>> @@ -819,7 +824,7 @@ typedef unsigned char *sk_buff_data_t;
>> * @dst_pending_confirm: need to confirm neighbour
>> * @decrypted: Decrypted SKB
>> * @slow_gro: state present at GRO time, slower prepare step required
>> - * @mono_delivery_time: When set, skb->tstamp has the
>> + * @tstamp_type: When set, skb->tstamp has the
>> * delivery_time in mono clock base (i.e. EDT). Otherwise, the
>> * skb->tstamp has the (rcv) timestamp at ingress and
>> * delivery_time at egress.
>> @@ -950,7 +955,7 @@ struct sk_buff {
>> /* private: */
>> __u8 __mono_tc_offset[0];
>> /* public: */
>> - __u8 mono_delivery_time:1; /* See SKB_MONO_DELIVERY_TIME_MASK */
>> + __u8 tstamp_type:1; /* See SKB_MONO_DELIVERY_TIME_MASK */
>
> Also remove reference to MONO_DELIVERY_TIME_MASK, or instead refer to
> skb_tstamp_type.
>
>> #ifdef CONFIG_NET_XGRESS
>> __u8 tc_at_ingress:1; /* See TC_AT_INGRESS_MASK */
>> __u8 tc_skip_classify:1;
>> @@ -4237,7 +4242,7 @@ static inline void skb_get_new_timestampns(const struct sk_buff *skb,
>> static inline void __net_timestamp(struct sk_buff *skb)
>> {
>> skb->tstamp = ktime_get_real();
>> - skb->mono_delivery_time = 0;
>> + skb->tstamp_type = CLOCK_REAL;
>> }
>>
>> static inline ktime_t net_timedelta(ktime_t t)
>> @@ -4246,10 +4251,18 @@ static inline ktime_t net_timedelta(ktime_t t)
>> }
>>
>> static inline void skb_set_delivery_time(struct sk_buff *skb, ktime_t kt,
>> - bool mono)
>> + u8 tstamp_type)
>> {
>> skb->tstamp = kt;
>> - skb->mono_delivery_time = kt && mono;
>> +
>> + switch (tstamp_type) {
>> + case CLOCK_REAL:
>> + skb->tstamp_type = CLOCK_REAL;
>> + break;
>> + case CLOCK_MONO:
>> + skb->tstamp_type = kt && tstamp_type;
>> + break;
>> + }
>
> Technically this leaves the tstamp_type undefined if (skb, 0, CLOCK_REAL)
Do you think i should be checking for valid value of tstamp before setting the tstamp_type ? Only then set it.
>> }
>>
>> DECLARE_STATIC_KEY_FALSE(netstamp_needed_key);
>> @@ -4259,8 +4272,8 @@ DECLARE_STATIC_KEY_FALSE(netstamp_needed_key);
>> */
>> static inline void skb_clear_delivery_time(struct sk_buff *skb)
>> {
>> - if (skb->mono_delivery_time) {
>> - skb->mono_delivery_time = 0;
>> + if (skb->tstamp_type) {
>> + skb->tstamp_type = CLOCK_REAL;
>> if (static_branch_unlikely(&netstamp_needed_key))
>> skb->tstamp = ktime_get_real();
>> else
>> @@ -4270,7 +4283,7 @@ static inline void skb_clear_delivery_time(struct sk_buff *skb)
>>
>> static inline void skb_clear_tstamp(struct sk_buff *skb)
>> {
>> - if (skb->mono_delivery_time)
>> + if (skb->tstamp_type)
>> return;
>>
>> skb->tstamp = 0;
>> @@ -4278,7 +4291,7 @@ static inline void skb_clear_tstamp(struct sk_buff *skb)
>>
>> static inline ktime_t skb_tstamp(const struct sk_buff *skb)
>> {
>> - if (skb->mono_delivery_time)
>> + if (skb->tstamp_type == CLOCK_MONO)
>> return 0;
>
> Should this be if (skb->tstamp_type), in line with skb_clear_tstamp,
> right above?
I think so too. I thought i will not alter the existing functionality and keep it as close to the previous working changes.
>
>> @@ -1649,7 +1649,7 @@ void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb,
>> arg->csumoffset) = csum_fold(csum_add(nskb->csum,
>> arg->csum));
>> nskb->ip_summed = CHECKSUM_NONE;
>> - nskb->mono_delivery_time = !!transmit_time;
>> + nskb->tstamp_type = !!transmit_time;
>
> In anticipation of more tstamp_types, explicitly set to CLOCK_MONO.
I will set it to SKB_CLOCK_MONO
>
>> if (txhash)
>> skb_set_hash(nskb, txhash, PKT_HASH_TYPE_L4);
>> ip_push_pending_frames(sk, &fl4);
Powered by blists - more mailing lists