diff mbox series

[net-next,v9,02/10] tcp: directly drop skb in cookie check for ipv4

Message ID 20240223102851.83749-3-kerneljasonxing@gmail.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series introduce drop reasons for tcp receive path | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next, async
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 960 this patch: 960
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 5 of 5 maintainers
netdev/build_clang success Errors and warnings before: 958 this patch: 958
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 977 this patch: 977
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 28 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-02-23--18-00 (tests: 1457)

Commit Message

Jason Xing Feb. 23, 2024, 10:28 a.m. UTC 
From: Jason Xing <kernelxing@tencent.com>

Only move the skb drop from tcp_v4_do_rcv() to cookie_v4_check() itself,
no other changes made. It can help us refine the specific drop reasons
later.

Signed-off-by: Jason Xing <kernelxing@tencent.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
--
v9
Link: https://lore.kernel.org/netdev/c5640fc4-16dc-4058-97c6-bd84bae4fda1@kernel.org/
1. add reviewed-by tag (David)

v8
Link: https://lore.kernel.org/netdev/CANn89i+foA-AW3KCNw232eCC5GDi_3O0JG-mpvyiQJYuxKxnRA@mail.gmail.com/
1. add reviewed-by tag (Eric)

v7
Link: https://lore.kernel.org/all/20240219041350.95304-1-kuniyu@amazon.com/
1. add reviewed-by tag (Kuniyuki)
---
 net/ipv4/syncookies.c | 4 ++++
 net/ipv4/tcp_ipv4.c   | 2 +-
 2 files changed, 5 insertions(+), 1 deletion(-)

Comments

Kuniyuki Iwashima Feb. 23, 2024, 7:17 p.m. UTC | #1 
From: Jason Xing <kerneljasonxing@gmail.com>
Date: Fri, 23 Feb 2024 18:28:43 +0800
> From: Jason Xing <kernelxing@tencent.com>
> 
> Only move the skb drop from tcp_v4_do_rcv() to cookie_v4_check() itself,
> no other changes made. It can help us refine the specific drop reasons
> later.
> 
> Signed-off-by: Jason Xing <kernelxing@tencent.com>
> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
> Reviewed-by: Eric Dumazet <edumazet@google.com>
> Reviewed-by: David Ahern <dsahern@kernel.org>
> --
> v9
> Link: https://lore.kernel.org/netdev/c5640fc4-16dc-4058-97c6-bd84bae4fda1@kernel.org/
> 1. add reviewed-by tag (David)
> 
> v8
> Link: https://lore.kernel.org/netdev/CANn89i+foA-AW3KCNw232eCC5GDi_3O0JG-mpvyiQJYuxKxnRA@mail.gmail.com/
> 1. add reviewed-by tag (Eric)
> 
> v7
> Link: https://lore.kernel.org/all/20240219041350.95304-1-kuniyu@amazon.com/
> 1. add reviewed-by tag (Kuniyuki)
> ---
>  net/ipv4/syncookies.c | 4 ++++
>  net/ipv4/tcp_ipv4.c   | 2 +-
>  2 files changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c
> index be88bf586ff9..38f331da6677 100644
> --- a/net/ipv4/syncookies.c
> +++ b/net/ipv4/syncookies.c
> @@ -408,6 +408,7 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb)
>  	struct rtable *rt;
>  	__u8 rcv_wscale;
>  	int full_space;
> +	SKB_DR(reason);
>  
>  	if (!READ_ONCE(net->ipv4.sysctl_tcp_syncookies) ||
>  	    !th->ack || th->rst)
> @@ -477,10 +478,13 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb)
>  	 */
>  	if (ret)
>  		inet_sk(ret)->cork.fl.u.ip4 = fl4;
> +	else
> +		goto out_drop;

nit: It would be nice to use the same style with IPv6 change.

	if (!ret)
		goto out_drop;

	inet_sk(ret)->cork.fl.u.ip4 = fl4;

Otherwise looks good.

Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>


>  out:
>  	return ret;
>  out_free:
>  	reqsk_free(req);
>  out_drop:
> +	kfree_skb_reason(skb, reason);
>  	return NULL;
>  }
> diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
> index 0c50c5a32b84..0a944e109088 100644
> --- a/net/ipv4/tcp_ipv4.c
> +++ b/net/ipv4/tcp_ipv4.c
> @@ -1915,7 +1915,7 @@ int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
>  		struct sock *nsk = tcp_v4_cookie_check(sk, skb);
>  
>  		if (!nsk)
> -			goto discard;
> +			return 0;
>  		if (nsk != sk) {
>  			if (tcp_child_process(sk, nsk, skb)) {
>  				rsk = nsk;
> -- 
> 2.37.3
Kuniyuki Iwashima Feb. 23, 2024, 7:21 p.m. UTC | #2 
From: Kuniyuki Iwashima <kuniyu@amazon.com>
Date: Fri, 23 Feb 2024 11:17:36 -0800
> From: Jason Xing <kerneljasonxing@gmail.com>
> Date: Fri, 23 Feb 2024 18:28:43 +0800
> > From: Jason Xing <kernelxing@tencent.com>
> > 
> > Only move the skb drop from tcp_v4_do_rcv() to cookie_v4_check() itself,
> > no other changes made. It can help us refine the specific drop reasons
> > later.
> > 
> > Signed-off-by: Jason Xing <kernelxing@tencent.com>
> > Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
> > Reviewed-by: Eric Dumazet <edumazet@google.com>
> > Reviewed-by: David Ahern <dsahern@kernel.org>
> > --
> > v9
> > Link: https://lore.kernel.org/netdev/c5640fc4-16dc-4058-97c6-bd84bae4fda1@kernel.org/
> > 1. add reviewed-by tag (David)
> > 
> > v8
> > Link: https://lore.kernel.org/netdev/CANn89i+foA-AW3KCNw232eCC5GDi_3O0JG-mpvyiQJYuxKxnRA@mail.gmail.com/
> > 1. add reviewed-by tag (Eric)
> > 
> > v7
> > Link: https://lore.kernel.org/all/20240219041350.95304-1-kuniyu@amazon.com/
> > 1. add reviewed-by tag (Kuniyuki)
> > ---
> >  net/ipv4/syncookies.c | 4 ++++
> >  net/ipv4/tcp_ipv4.c   | 2 +-
> >  2 files changed, 5 insertions(+), 1 deletion(-)
> > 
> > diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c
> > index be88bf586ff9..38f331da6677 100644
> > --- a/net/ipv4/syncookies.c
> > +++ b/net/ipv4/syncookies.c
> > @@ -408,6 +408,7 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb)
> >  	struct rtable *rt;
> >  	__u8 rcv_wscale;
> >  	int full_space;
> > +	SKB_DR(reason);
> >  
> >  	if (!READ_ONCE(net->ipv4.sysctl_tcp_syncookies) ||
> >  	    !th->ack || th->rst)
> > @@ -477,10 +478,13 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb)
> >  	 */
> >  	if (ret)
> >  		inet_sk(ret)->cork.fl.u.ip4 = fl4;
> > +	else
> > +		goto out_drop;
> 
> nit: It would be nice to use the same style with IPv6 change.
> 
> 	if (!ret)
> 		goto out_drop;
> 
> 	inet_sk(ret)->cork.fl.u.ip4 = fl4;

I just noticed you changed so in the next patch, so please
ignore my comment.
diff mbox series

Patch

diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c
index be88bf586ff9..38f331da6677 100644
--- a/net/ipv4/syncookies.c
+++ b/net/ipv4/syncookies.c
@@ -408,6 +408,7 @@  struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb)
 	struct rtable *rt;
 	__u8 rcv_wscale;
 	int full_space;
+	SKB_DR(reason);
 
 	if (!READ_ONCE(net->ipv4.sysctl_tcp_syncookies) ||
 	    !th->ack || th->rst)
@@ -477,10 +478,13 @@  struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb)
 	 */
 	if (ret)
 		inet_sk(ret)->cork.fl.u.ip4 = fl4;
+	else
+		goto out_drop;
 out:
 	return ret;
 out_free:
 	reqsk_free(req);
 out_drop:
+	kfree_skb_reason(skb, reason);
 	return NULL;
 }
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 0c50c5a32b84..0a944e109088 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1915,7 +1915,7 @@  int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
 		struct sock *nsk = tcp_v4_cookie_check(sk, skb);
 
 		if (!nsk)
-			goto discard;
+			return 0;
 		if (nsk != sk) {
 			if (tcp_child_process(sk, nsk, skb)) {
 				rsk = nsk;