From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E6F61C433FE for ; Wed, 16 Mar 2022 03:17:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1353451AbiCPDS1 (ORCPT ); Tue, 15 Mar 2022 23:18:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46380 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234584AbiCPDSY (ORCPT ); Tue, 15 Mar 2022 23:18:24 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EB84E5E15C; Tue, 15 Mar 2022 20:17:10 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id A336FB8181C; Wed, 16 Mar 2022 03:17:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C6187C340E8; Wed, 16 Mar 2022 03:17:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1647400628; bh=PlSgv56mxNRopY1yc16lOuudQ7ENlgRXJivgph2Ss9M=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=UGPsFoLJYgTGlZ8MU0IVJ+3MuoMplzorQGMbSsXLoCyfFEKaiRK3+TYtaOfynic2m hZWSpYmyL6rCTW/6D3M0L26M1HviLCZjpIuKbvq1gYizHSCjiKPZ/KmvvQMuNwUcyt xOBuGqSHSC4W3sDacQczboPIPIksiFQ4notEKneTAEIB+ATiZl8qmGlAIUVOMV3Ms1 Nw1azlYZNZi58uJTV56EoeGZRK5SIuAo1+1kzgbGHjpbFKi7j7FOG2EWccTsNeK7qb BgMB2kTc+O8VBHFLVtIfz+wDbeNAcIVv8u7BivUe2mwN6v2v7ml2bVCclcmNydvjLl JRa/hfmpuIvDQ== Date: Tue, 15 Mar 2022 20:17:06 -0700 From: Jakub Kicinski To: menglong8.dong@gmail.com Cc: dsahern@kernel.org, rostedt@goodmis.org, mingo@redhat.com, xeb@mail.ru, davem@davemloft.net, yoshfuji@linux-ipv6.org, imagedong@tencent.com, edumazet@google.com, kafai@fb.com, talalahmad@google.com, keescook@chromium.org, alobakin@pm.me, flyingpeng@tencent.com, mengensun@tencent.com, dongli.zhang@oracle.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Biao Jiang Subject: Re: [PATCH net-next 3/3] net: ipgre: add skb drop reasons to gre_rcv() Message-ID: <20220315201706.464d5ecd@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> In-Reply-To: <20220314133312.336653-4-imagedong@tencent.com> References: <20220314133312.336653-1-imagedong@tencent.com> <20220314133312.336653-4-imagedong@tencent.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 14 Mar 2022 21:33:12 +0800 menglong8.dong@gmail.com wrote: > From: Menglong Dong > > Replace kfree_skb() used in gre_rcv() with kfree_skb_reason(). With > previous patch, we can tell that no tunnel device is found when > PACKET_NEXT is returned by erspan_rcv() or ipgre_rcv(). > > In this commit, following new drop reasons are added: > > SKB_DROP_REASON_GRE_CSUM > SKB_DROP_REASON_GRE_NOTUNNEL > > Reviewed-by: Hao Peng > Reviewed-by: Biao Jiang > Signed-off-by: Menglong Dong > --- > include/linux/skbuff.h | 2 ++ > include/trace/events/skb.h | 2 ++ > net/ipv4/ip_gre.c | 28 ++++++++++++++++++---------- > 3 files changed, 22 insertions(+), 10 deletions(-) > > diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h > index 5edb704af5bb..4f5e58e717ee 100644 > --- a/include/linux/skbuff.h > +++ b/include/linux/skbuff.h > @@ -448,6 +448,8 @@ enum skb_drop_reason { > SKB_DROP_REASON_GRE_NOHANDLER, /* no handler found (version not > * supported?) > */ > + SKB_DROP_REASON_GRE_CSUM, /* GRE csum error */ > + SKB_DROP_REASON_GRE_NOTUNNEL, /* no tunnel device found */ > SKB_DROP_REASON_MAX, > }; > > diff --git a/include/trace/events/skb.h b/include/trace/events/skb.h > index f2bcffdc4bae..e8f95c96cf9d 100644 > --- a/include/trace/events/skb.h > +++ b/include/trace/events/skb.h > @@ -63,6 +63,8 @@ > EM(SKB_DROP_REASON_TAP_TXFILTER, TAP_TXFILTER) \ > EM(SKB_DROP_REASON_GRE_VERSION, GRE_VERSION) \ > EM(SKB_DROP_REASON_GRE_NOHANDLER, GRE_NOHANDLER) \ > + EM(SKB_DROP_REASON_GRE_CSUM, GRE_CSUM) \ > + EM(SKB_DROP_REASON_GRE_NOTUNNEL, GRE_NOTUNNEL) \ > EMe(SKB_DROP_REASON_MAX, MAX) > > #undef EM > diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c > index b1579d8374fd..b989239e4abc 100644 > --- a/net/ipv4/ip_gre.c > +++ b/net/ipv4/ip_gre.c > @@ -421,9 +421,10 @@ static int ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi, > > static int gre_rcv(struct sk_buff *skb) > { > + enum skb_drop_reason reason = SKB_DROP_REASON_NOT_SPECIFIED; > struct tnl_ptk_info tpi; > bool csum_err = false; > - int hdr_len; > + int hdr_len, ret; > > #ifdef CONFIG_NET_IPGRE_BROADCAST > if (ipv4_is_multicast(ip_hdr(skb)->daddr)) { > @@ -438,19 +439,26 @@ static int gre_rcv(struct sk_buff *skb) I feel like gre_parse_header() is a good candidate for converting to return a reason instead of errno. > goto drop; > > if (unlikely(tpi.proto == htons(ETH_P_ERSPAN) || > - tpi.proto == htons(ETH_P_ERSPAN2))) { > - if (erspan_rcv(skb, &tpi, hdr_len) == PACKET_RCVD) > - return 0; > - goto out; > - } > + tpi.proto == htons(ETH_P_ERSPAN2))) > + ret = erspan_rcv(skb, &tpi, hdr_len); > + else > + ret = ipgre_rcv(skb, &tpi, hdr_len); ipgre_rcv() OTOH may be better off taking the reason as an output argument. Assuming PACKET_REJECT means NOMEM is a little fragile. > > - if (ipgre_rcv(skb, &tpi, hdr_len) == PACKET_RCVD) > + switch (ret) { > + case PACKET_NEXT: > + reason = SKB_DROP_REASON_GRE_NOTUNNEL; > + break; > + case PACKET_RCVD: > return 0; > - > -out: > + case PACKET_REJECT: > + reason = SKB_DROP_REASON_NOMEM; > + break; > + } > icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); > drop: > - kfree_skb(skb); > + if (csum_err) > + reason = SKB_DROP_REASON_GRE_CSUM; > + kfree_skb_reason(skb, reason); > return 0; > } >