diff mbox series

[net-next,v6,04/11] tcp: directly drop skb in cookie check for ipv6

Message ID 20240219032838.91723-5-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State Superseded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: 942 this patch: 942
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: 957 this patch: 957
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: 959 this patch: 959
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 35 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 pending net-next-2024-02-19--09-00 (tests: 391)

Commit Message

Jason Xing Feb. 19, 2024, 3:28 a.m. UTC 
From: Jason Xing <kernelxing@tencent.com>

Like previous patch does, only moving skb drop logical code to
cookie_v6_check() for later refinement.

Signed-off-by: Jason Xing <kernelxing@tencent.com>
--
v6
Link: https://lore.kernel.org/all/c987d2c79e4a4655166eb8eafef473384edb37fb.camel@redhat.com/
Link: https://lore.kernel.org/all/CAL+tcoAgSjwsmFnDh_Gs9ZgMi-y5awtVx+4VhJPNRADjo7LLSA@mail.gmail.com/
1. take one case into consideration, behave like old days, or else it will trigger errors.

v5
Link: https://lore.kernel.org/netdev/CANn89iKz7=1q7e8KY57Dn3ED7O=RCOfLxoHQKO4eNXnZa1OPWg@mail.gmail.com/
1. avoid duplication of these opt_skb tests/actions (Eric)
---
 net/ipv6/syncookies.c | 4 ++++
 net/ipv6/tcp_ipv6.c   | 7 +++----
 2 files changed, 7 insertions(+), 4 deletions(-)

Comments

Kuniyuki Iwashima Feb. 19, 2024, 4:38 a.m. UTC | #1 
From: Jason Xing <kerneljasonxing@gmail.com>
Date: Mon, 19 Feb 2024 11:28:31 +0800
> From: Jason Xing <kernelxing@tencent.com>
> 
> Like previous patch does, only moving skb drop logical code to
> cookie_v6_check() for later refinement.
> 
> Signed-off-by: Jason Xing <kernelxing@tencent.com>
> --
> v6
> Link: https://lore.kernel.org/all/c987d2c79e4a4655166eb8eafef473384edb37fb.camel@redhat.com/
> Link: https://lore.kernel.org/all/CAL+tcoAgSjwsmFnDh_Gs9ZgMi-y5awtVx+4VhJPNRADjo7LLSA@mail.gmail.com/
> 1. take one case into consideration, behave like old days, or else it will trigger errors.
> 
> v5
> Link: https://lore.kernel.org/netdev/CANn89iKz7=1q7e8KY57Dn3ED7O=RCOfLxoHQKO4eNXnZa1OPWg@mail.gmail.com/
> 1. avoid duplication of these opt_skb tests/actions (Eric)
> ---
>  net/ipv6/syncookies.c | 4 ++++
>  net/ipv6/tcp_ipv6.c   | 7 +++----
>  2 files changed, 7 insertions(+), 4 deletions(-)
> 
> diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c
> index 6b9c69278819..ea0d9954a29f 100644
> --- a/net/ipv6/syncookies.c
> +++ b/net/ipv6/syncookies.c
> @@ -177,6 +177,7 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
>  	struct sock *ret = sk;
>  	__u8 rcv_wscale;
>  	int full_space;
> +	SKB_DR(reason);
>  
>  	if (!READ_ONCE(net->ipv4.sysctl_tcp_syncookies) ||
>  	    !th->ack || th->rst)
> @@ -256,10 +257,13 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
>  	ireq->ecn_ok &= cookie_ecn_ok(net, dst);
>  
>  	ret = tcp_get_cookie_sock(sk, skb, req, dst);
> +	if (!ret)
> +		goto out_drop;
>  out:
>  	return ret;
>  out_free:
>  	reqsk_free(req);
>  out_drop:
> +	kfree_skb_reason(skb, reason);
>  	return NULL;
>  }
> diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
> index 57b25b1fc9d9..4cfeedfb871f 100644
> --- a/net/ipv6/tcp_ipv6.c
> +++ b/net/ipv6/tcp_ipv6.c
> @@ -1653,12 +1653,11 @@ int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
>  	if (sk->sk_state == TCP_LISTEN) {
>  		struct sock *nsk = tcp_v6_cookie_check(sk, skb);
>  
> -		if (!nsk)
> -			goto discard;
> -
> -		if (nsk != sk) {
> +		if (nsk && nsk != sk) {
>  			if (tcp_child_process(sk, nsk, skb))
>  				goto reset;
> +		}
> +		if (!nsk || nsk != sk) {

!nsk is redundant, when nsk is NULL, nsk != sk is true.

We can keep the original nsk != sk check and call tcp_child_process()
only when nsk is not NULL:

---8<---
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 57b25b1fc9d9..0c180bb8187f 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1653,11 +1653,8 @@ int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
 	if (sk->sk_state == TCP_LISTEN) {
 		struct sock *nsk = tcp_v6_cookie_check(sk, skb);
 
-		if (!nsk)
-			goto discard;
-
 		if (nsk != sk) {
-			if (tcp_child_process(sk, nsk, skb))
+			if (nsk && tcp_child_process(sk, nsk, skb))
 				goto reset;
 			if (opt_skb)
 				__kfree_skb(opt_skb);
---8<---
Jason Xing Feb. 19, 2024, 4:57 a.m. UTC | #2 
On Mon, Feb 19, 2024 at 12:38 PM Kuniyuki Iwashima <kuniyu@amazon.com> wrote:
>
> From: Jason Xing <kerneljasonxing@gmail.com>
> Date: Mon, 19 Feb 2024 11:28:31 +0800
> > From: Jason Xing <kernelxing@tencent.com>
> >
> > Like previous patch does, only moving skb drop logical code to
> > cookie_v6_check() for later refinement.
> >
> > Signed-off-by: Jason Xing <kernelxing@tencent.com>
> > --
> > v6
> > Link: https://lore.kernel.org/all/c987d2c79e4a4655166eb8eafef473384edb37fb.camel@redhat.com/
> > Link: https://lore.kernel.org/all/CAL+tcoAgSjwsmFnDh_Gs9ZgMi-y5awtVx+4VhJPNRADjo7LLSA@mail.gmail.com/
> > 1. take one case into consideration, behave like old days, or else it will trigger errors.
> >
> > v5
> > Link: https://lore.kernel.org/netdev/CANn89iKz7=1q7e8KY57Dn3ED7O=RCOfLxoHQKO4eNXnZa1OPWg@mail.gmail.com/
> > 1. avoid duplication of these opt_skb tests/actions (Eric)
> > ---
> >  net/ipv6/syncookies.c | 4 ++++
> >  net/ipv6/tcp_ipv6.c   | 7 +++----
> >  2 files changed, 7 insertions(+), 4 deletions(-)
> >
> > diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c
> > index 6b9c69278819..ea0d9954a29f 100644
> > --- a/net/ipv6/syncookies.c
> > +++ b/net/ipv6/syncookies.c
> > @@ -177,6 +177,7 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
> >       struct sock *ret = sk;
> >       __u8 rcv_wscale;
> >       int full_space;
> > +     SKB_DR(reason);
> >
> >       if (!READ_ONCE(net->ipv4.sysctl_tcp_syncookies) ||
> >           !th->ack || th->rst)
> > @@ -256,10 +257,13 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
> >       ireq->ecn_ok &= cookie_ecn_ok(net, dst);
> >
> >       ret = tcp_get_cookie_sock(sk, skb, req, dst);
> > +     if (!ret)
> > +             goto out_drop;
> >  out:
> >       return ret;
> >  out_free:
> >       reqsk_free(req);
> >  out_drop:
> > +     kfree_skb_reason(skb, reason);
> >       return NULL;
> >  }
> > diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
> > index 57b25b1fc9d9..4cfeedfb871f 100644
> > --- a/net/ipv6/tcp_ipv6.c
> > +++ b/net/ipv6/tcp_ipv6.c
> > @@ -1653,12 +1653,11 @@ int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
> >       if (sk->sk_state == TCP_LISTEN) {
> >               struct sock *nsk = tcp_v6_cookie_check(sk, skb);
> >
> > -             if (!nsk)
> > -                     goto discard;
> > -
> > -             if (nsk != sk) {
> > +             if (nsk && nsk != sk) {
> >                       if (tcp_child_process(sk, nsk, skb))
> >                               goto reset;
> > +             }
> > +             if (!nsk || nsk != sk) {
>
> !nsk is redundant, when nsk is NULL, nsk != sk is true.
>
> We can keep the original nsk != sk check and call tcp_child_process()
> only when nsk is not NULL:
>
> ---8<---
> diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
> index 57b25b1fc9d9..0c180bb8187f 100644
> --- a/net/ipv6/tcp_ipv6.c
> +++ b/net/ipv6/tcp_ipv6.c
> @@ -1653,11 +1653,8 @@ int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
>         if (sk->sk_state == TCP_LISTEN) {
>                 struct sock *nsk = tcp_v6_cookie_check(sk, skb);
>
> -               if (!nsk)
> -                       goto discard;
> -
>                 if (nsk != sk) {
> -                       if (tcp_child_process(sk, nsk, skb))
> +                       if (nsk && tcp_child_process(sk, nsk, skb))
>                                 goto reset;
>                         if (opt_skb)
>                                 __kfree_skb(opt_skb);
> ---8<---

Agreed. It looks much better. I'll take it. Thanks!
diff mbox series

Patch

diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c
index 6b9c69278819..ea0d9954a29f 100644
--- a/net/ipv6/syncookies.c
+++ b/net/ipv6/syncookies.c
@@ -177,6 +177,7 @@  struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
 	struct sock *ret = sk;
 	__u8 rcv_wscale;
 	int full_space;
+	SKB_DR(reason);
 
 	if (!READ_ONCE(net->ipv4.sysctl_tcp_syncookies) ||
 	    !th->ack || th->rst)
@@ -256,10 +257,13 @@  struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
 	ireq->ecn_ok &= cookie_ecn_ok(net, dst);
 
 	ret = tcp_get_cookie_sock(sk, skb, req, dst);
+	if (!ret)
+		goto out_drop;
 out:
 	return ret;
 out_free:
 	reqsk_free(req);
 out_drop:
+	kfree_skb_reason(skb, reason);
 	return NULL;
 }
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 57b25b1fc9d9..4cfeedfb871f 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1653,12 +1653,11 @@  int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
 	if (sk->sk_state == TCP_LISTEN) {
 		struct sock *nsk = tcp_v6_cookie_check(sk, skb);
 
-		if (!nsk)
-			goto discard;
-
-		if (nsk != sk) {
+		if (nsk && nsk != sk) {
 			if (tcp_child_process(sk, nsk, skb))
 				goto reset;
+		}
+		if (!nsk || nsk != sk) {
 			if (opt_skb)
 				__kfree_skb(opt_skb);
 			return 0;