From: Kuniyuki Iwashima <kuniyu@amazon.com>
To: <sinquersw@gmail.com>
Cc: <andrii@kernel.org>, <ast@kernel.org>, <bpf@vger.kernel.org>,
<daniel@iogearbox.net>, <davem@davemloft.net>,
<dsahern@kernel.org>, <edumazet@google.com>, <haoluo@google.com>,
<john.fastabend@gmail.com>, <jolsa@kernel.org>,
<kpsingh@kernel.org>, <kuba@kernel.org>, <kuni1840@gmail.com>,
<kuniyu@amazon.com>, <martin.lau@linux.dev>, <mykolal@fb.com>,
<netdev@vger.kernel.org>, <pabeni@redhat.com>, <sdf@google.com>,
<song@kernel.org>, <yonghong.song@linux.dev>
Subject: Re: [PATCH v1 bpf-next 03/11] tcp: Clean up goto labels in cookie_v[46]_check().
Date: Mon, 16 Oct 2023 17:30:58 -0700 [thread overview]
Message-ID: <20231017003058.6254-1-kuniyu@amazon.com> (raw)
In-Reply-To: <effba957-26ce-4b04-841a-40c863e6931f@gmail.com>
From: Kui-Feng Lee <sinquersw@gmail.com>
Date: Mon, 16 Oct 2023 17:00:39 -0700
> On 10/13/23 15:04, Kuniyuki Iwashima wrote:
> > We will add a SOCK_OPS hook to validate SYN Cookie.
> >
> > We invoke the hook after allocating reqsk. In case it fails,
> > we will respond with RST instead of just dropping the ACK.
> >
> > Then, there would be more duplicated error handling patterns.
> > To avoid that, let's clean up goto labels.
> >
> > Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
> > ---
> > net/ipv4/syncookies.c | 22 +++++++++++-----------
> > net/ipv6/syncookies.c | 4 ++--
> > 2 files changed, 13 insertions(+), 13 deletions(-)
> >
> > diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c
> > index 64280cf42667..b0cf6f4d66d8 100644
> > --- a/net/ipv4/syncookies.c
> > +++ b/net/ipv4/syncookies.c
> > @@ -369,11 +369,10 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb)
> > if (!cookie_timestamp_decode(net, &tcp_opt))
> > goto out;
> >
> > - ret = NULL;
> > req = cookie_tcp_reqsk_alloc(&tcp_request_sock_ops,
> > &tcp_request_sock_ipv4_ops, sk, skb);
> > if (!req)
> > - goto out;
> > + goto out_drop;
> >
> > ireq = inet_rsk(req);
> > treq = tcp_rsk(req);
> > @@ -405,10 +404,8 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb)
> > */
> > RCU_INIT_POINTER(ireq->ireq_opt, tcp_v4_save_options(net, skb));
> >
> > - if (security_inet_conn_request(sk, skb, req)) {
> > - reqsk_free(req);
> > - goto out;
> > - }
> > + if (security_inet_conn_request(sk, skb, req))
> > + goto out_free;
> >
> > req->num_retrans = 0;
> >
> > @@ -425,10 +422,8 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb)
> > ireq->ir_loc_addr, th->source, th->dest, sk->sk_uid);
> > security_req_classify_flow(req, flowi4_to_flowi_common(&fl4));
> > rt = ip_route_output_key(net, &fl4);
> > - if (IS_ERR(rt)) {
> > - reqsk_free(req);
> > - goto out;
> > - }
> > + if (IS_ERR(rt))
> > + goto out_free;
> >
> > /* Try to redo what tcp_v4_send_synack did. */
> > req->rsk_window_clamp = tp->window_clamp ? :dst_metric(&rt->dst, RTAX_WINDOW);
> > @@ -452,5 +447,10 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb)
> > */
> > if (ret)
> > inet_sk(ret)->cork.fl.u.ip4 = fl4;
> > -out: return ret;
> > +out:
> > + return ret;
> > +out_free:
> > + reqsk_free(req);
> > +out_drop:
> > + return NULL;
> > }
>
> Looks like you don't use out_free and out_drop at all
> in the patch 5 & 6. Are these changes still necessary?
> Especially, the line 'goto out_drop' can be 'return NULL' concisely.
I think it's hard to follow a function where goto and return
are mixed, so I cleaned up the labels while at it.
next prev parent reply other threads:[~2023-10-17 0:31 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-13 22:04 [PATCH v1 bpf-next 00/11] bpf: tcp: Add SYN Cookie generation/validation SOCK_OPS hooks Kuniyuki Iwashima
2023-10-13 22:04 ` [PATCH v1 bpf-next 01/11] tcp: Clean up reverse xmas tree in cookie_v[46]_check() Kuniyuki Iwashima
2023-10-13 22:04 ` [PATCH v1 bpf-next 02/11] tcp: Cache sock_net(sk) " Kuniyuki Iwashima
2023-10-13 22:04 ` [PATCH v1 bpf-next 03/11] tcp: Clean up goto labels " Kuniyuki Iwashima
2023-10-17 0:00 ` Kui-Feng Lee
2023-10-17 0:30 ` Kuniyuki Iwashima [this message]
2023-10-13 22:04 ` [PATCH v1 bpf-next 04/11] tcp: Don't initialise tp->tsoffset in tcp_get_cookie_sock() Kuniyuki Iwashima
2023-10-13 22:04 ` [PATCH v1 bpf-next 05/11] bpf: tcp: Add SYN Cookie generation SOCK_OPS hook Kuniyuki Iwashima
2023-10-18 0:54 ` Martin KaFai Lau
2023-10-18 17:00 ` Kuniyuki Iwashima
2023-10-13 22:04 ` [PATCH v1 bpf-next 06/11] bpf: tcp: Add SYN Cookie validation " Kuniyuki Iwashima
2023-10-16 20:38 ` Stanislav Fomichev
2023-10-16 22:02 ` Kuniyuki Iwashima
2023-10-17 16:52 ` Kuniyuki Iwashima
2023-10-13 22:04 ` [PATCH v1 bpf-next 07/11] bpf: Make bpf_sock_ops.replylong[1] writable Kuniyuki Iwashima
2023-10-13 22:04 ` [PATCH v1 bpf-next 08/11] bpf: tcp: Make TS available for SYN Cookie storage Kuniyuki Iwashima
2023-10-13 22:04 ` [PATCH v1 bpf-next 09/11] tcp: Split cookie_ecn_ok() Kuniyuki Iwashima
2023-10-13 22:04 ` [PATCH v1 bpf-next 10/11] bpf: tcp: Make WS, SACK, ECN configurable from BPF SYN Cookie Kuniyuki Iwashima
2023-10-18 1:08 ` Martin KaFai Lau
2023-10-18 17:02 ` Kuniyuki Iwashima
2023-10-13 22:04 ` [PATCH v1 bpf-next 11/11] selftest: bpf: Test BPF_SOCK_OPS_(GEN|CHECK)_SYNCOOKIE_CB Kuniyuki Iwashima
2023-10-17 5:50 ` Martin KaFai Lau
2023-10-17 16:29 ` Kuniyuki Iwashima
2023-10-16 13:05 ` [PATCH v1 bpf-next 00/11] bpf: tcp: Add SYN Cookie generation/validation SOCK_OPS hooks Daniel Borkmann
2023-10-16 16:11 ` Kuniyuki Iwashima
2023-10-16 14:19 ` Willem de Bruijn
2023-10-16 16:46 ` Kuniyuki Iwashima
2023-10-16 18:41 ` Willem de Bruijn
2023-10-17 5:53 ` Martin KaFai Lau
2023-10-17 16:48 ` Kuniyuki Iwashima
2023-10-18 6:19 ` Martin KaFai Lau
2023-10-18 8:02 ` Eric Dumazet
2023-10-18 17:20 ` Kuniyuki Iwashima
2023-10-18 21:47 ` Kui-Feng Lee
2023-10-18 22:31 ` Kuniyuki Iwashima
2023-10-19 7:25 ` Martin KaFai Lau
2023-10-19 18:01 ` Kuniyuki Iwashima
2023-10-20 19:59 ` Martin KaFai Lau
2023-10-20 23:10 ` Kuniyuki Iwashima
2023-10-21 6:48 ` Kuniyuki Iwashima
2023-10-23 21:35 ` Martin KaFai Lau
2023-10-24 0:37 ` Kui-Feng Lee
2023-10-24 1:22 ` Kuniyuki Iwashima
2023-10-24 17:55 ` Kui-Feng Lee
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20231017003058.6254-1-kuniyu@amazon.com \
--to=kuniyu@amazon.com \
--cc=andrii@kernel.org \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=davem@davemloft.net \
--cc=dsahern@kernel.org \
--cc=edumazet@google.com \
--cc=haoluo@google.com \
--cc=john.fastabend@gmail.com \
--cc=jolsa@kernel.org \
--cc=kpsingh@kernel.org \
--cc=kuba@kernel.org \
--cc=kuni1840@gmail.com \
--cc=martin.lau@linux.dev \
--cc=mykolal@fb.com \
--cc=netdev@vger.kernel.org \
--cc=pabeni@redhat.com \
--cc=sdf@google.com \
--cc=sinquersw@gmail.com \
--cc=song@kernel.org \
--cc=yonghong.song@linux.dev \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).