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[79.55.200.170]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-432da299dadsm189813325e9.43.2024.11.19.02.42.26 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 19 Nov 2024 02:42:27 -0800 (PST) Message-ID: <82c02bbc-5d64-464d-83c1-66f1d71a1a44@redhat.com> Date: Tue, 19 Nov 2024 11:42:26 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH net-next v4 2/4] net: ipv6: ioam6_iptunnel: mitigate 2-realloc issue To: Justin Iurman , netdev@vger.kernel.org Cc: davem@davemloft.net, dsahern@kernel.org, edumazet@google.com, kuba@kernel.org, horms@kernel.org, linux-kernel@vger.kernel.org References: <20241118131502.10077-1-justin.iurman@uliege.be> <20241118131502.10077-3-justin.iurman@uliege.be> Content-Language: en-US From: Paolo Abeni In-Reply-To: <20241118131502.10077-3-justin.iurman@uliege.be> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 11/18/24 14:15, Justin Iurman wrote: > @@ -387,45 +392,40 @@ static int ioam6_output(struct net *net, struct sock *sk, struct sk_buff *skb) > goto drop; > } > > - err = skb_cow_head(skb, LL_RESERVED_SPACE(dst->dev)); > - if (unlikely(err)) > - goto drop; > + if (unlikely(!dst)) { > + struct ipv6hdr *hdr = ipv6_hdr(skb); > + struct flowi6 fl6; > + > + memset(&fl6, 0, sizeof(fl6)); > + fl6.daddr = hdr->daddr; > + fl6.saddr = hdr->saddr; > + fl6.flowlabel = ip6_flowinfo(hdr); > + fl6.flowi6_mark = skb->mark; > + fl6.flowi6_proto = hdr->nexthdr; > + > + dst = ip6_route_output(net, NULL, &fl6); > + if (dst->error) { > + err = dst->error; > + dst_release(dst); > + goto drop; > + } > > - if (!ipv6_addr_equal(&orig_daddr, &ipv6_hdr(skb)->daddr)) { > local_bh_disable(); > - dst = dst_cache_get(&ilwt->cache); > + dst_cache_set_ip6(&ilwt->cache, dst, &fl6.saddr); > local_bh_enable(); > > - if (unlikely(!dst)) { > - struct ipv6hdr *hdr = ipv6_hdr(skb); > - struct flowi6 fl6; > - > - memset(&fl6, 0, sizeof(fl6)); > - fl6.daddr = hdr->daddr; > - fl6.saddr = hdr->saddr; > - fl6.flowlabel = ip6_flowinfo(hdr); > - fl6.flowi6_mark = skb->mark; > - fl6.flowi6_proto = hdr->nexthdr; > - > - dst = ip6_route_output(net, NULL, &fl6); > - if (dst->error) { > - err = dst->error; > - dst_release(dst); > - goto drop; > - } > - > - local_bh_disable(); > - dst_cache_set_ip6(&ilwt->cache, dst, &fl6.saddr); > - local_bh_enable(); > - } > + err = skb_cow_head(skb, LL_RESERVED_SPACE(dst->dev)); > + if (unlikely(err)) > + goto drop; > + } > > - skb_dst_drop(skb); > - skb_dst_set(skb, dst); > + skb_dst_drop(skb); > + skb_dst_set(skb, dst); Why the above 2 statements are not done only in case of ip address match, as in the existing code? > > + if (!ipv6_addr_equal(&orig_daddr, &ipv6_hdr(skb)->daddr)) > return dst_output(net, sk, skb); > - } Thanks, Paolo