netdev - Re: [PATCH net-next v4 1/5] tcp: add dropreasons definitions and prepare for cookie check

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

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CANn89i+iELpsoea6+C-08m6+=JkneEEM=nAj-28eNtcOCkwQjw@mail.gmail.com>
Date: Tue, 13 Feb 2024 16:23:53 +0100
From: Eric Dumazet <edumazet@...gle.com>
To: Jason Xing <kerneljasonxing@...il.com>
Cc: davem@...emloft.net, kuba@...nel.org, pabeni@...hat.com, 
	dsahern@...nel.org, kuniyu@...zon.com, netdev@...r.kernel.org, 
	Jason Xing <kernelxing@...cent.com>
Subject: Re: [PATCH net-next v4 1/5] tcp: add dropreasons definitions and
 prepare for cookie check

On Tue, Feb 13, 2024 at 2:42 PM Jason Xing <kerneljasonxing@...il.com> wrote:
>
> From: Jason Xing <kernelxing@...cent.com>
>
> Only add five drop reasons to detect the condition of skb dropped
> in cookie check for later use.
>
> Signed-off-by: Jason Xing <kernelxing@...cent.com>
> --
> v2
> Link: https://lore.kernel.org/netdev/20240212172302.3f95e454@kernel.org/
> 1. fix misspelled name in kdoc as Jakub said
> ---
>  include/net/dropreason-core.h | 21 +++++++++++++++++++++
>  1 file changed, 21 insertions(+)
>
> diff --git a/include/net/dropreason-core.h b/include/net/dropreason-core.h
> index 6d3a20163260..065caba42b0b 100644
> --- a/include/net/dropreason-core.h
> +++ b/include/net/dropreason-core.h
> @@ -6,6 +6,7 @@
>  #define DEFINE_DROP_REASON(FN, FNe)    \
>         FN(NOT_SPECIFIED)               \
>         FN(NO_SOCKET)                   \
> +       FN(NO_REQSK_ALLOC)              \
>         FN(PKT_TOO_SMALL)               \
>         FN(TCP_CSUM)                    \
>         FN(SOCKET_FILTER)               \
> @@ -43,10 +44,12 @@
>         FN(TCP_FASTOPEN)                \
>         FN(TCP_OLD_ACK)                 \
>         FN(TCP_TOO_OLD_ACK)             \
> +       FN(COOKIE_NOCHILD)              \
>         FN(TCP_ACK_UNSENT_DATA)         \
>         FN(TCP_OFO_QUEUE_PRUNE)         \
>         FN(TCP_OFO_DROP)                \
>         FN(IP_OUTNOROUTES)              \
> +       FN(IP_ROUTEOUTPUTKEY)           \
>         FN(BPF_CGROUP_EGRESS)           \
>         FN(IPV6DISABLED)                \
>         FN(NEIGH_CREATEFAIL)            \
> @@ -54,6 +57,7 @@
>         FN(NEIGH_QUEUEFULL)             \
>         FN(NEIGH_DEAD)                  \
>         FN(TC_EGRESS)                   \
> +       FN(SECURITY_HOOK)               \
>         FN(QDISC_DROP)                  \
>         FN(CPU_BACKLOG)                 \
>         FN(XDP)                         \
> @@ -71,6 +75,7 @@
>         FN(TAP_TXFILTER)                \
>         FN(ICMP_CSUM)                   \
>         FN(INVALID_PROTO)               \
> +       FN(INVALID_DST)                 \

We already have  SKB_DROP_REASON_IP_OUTNOROUTES ?

>         FN(IP_INADDRERRORS)             \
>         FN(IP_INNOROUTES)               \
>         FN(PKT_TOO_BIG)                 \
> @@ -107,6 +112,11 @@ enum skb_drop_reason {
>         SKB_DROP_REASON_NOT_SPECIFIED,
>         /** @SKB_DROP_REASON_NO_SOCKET: socket not found */
>         SKB_DROP_REASON_NO_SOCKET,
> +       /**
> +        * @SKB_DROP_REASON_NO_REQSK_ALLOC: request socket allocation failed
> +        * probably because of no available memory for now
> +        */

We have SKB_DROP_REASON_NOMEM, I do not think we need to be very precise.
REQSK are implementation details.

> +       SKB_DROP_REASON_NO_REQSK_ALLOC,
>         /** @SKB_DROP_REASON_PKT_TOO_SMALL: packet size is too small */
>         SKB_DROP_REASON_PKT_TOO_SMALL,
>         /** @SKB_DROP_REASON_TCP_CSUM: TCP checksum error */
> @@ -243,6 +253,11 @@ enum skb_drop_reason {
>         SKB_DROP_REASON_TCP_OLD_ACK,
>         /** @SKB_DROP_REASON_TCP_TOO_OLD_ACK: TCP ACK is too old */
>         SKB_DROP_REASON_TCP_TOO_OLD_ACK,
> +       /**
> +        * @SKB_DROP_REASON_COOKIE_NOCHILD: no child socket in cookie mode
> +        * reason could be the failure of child socket allocation

This makes no sense to me. There are many reasons for this.

Either the reason is deterministic, or just reuse a generic and
existing drop_reason that can be augmented later.

You are adding weak or duplicate drop_reasons, we already have them.