From: David Ahern <dsahern@kernel.org>
To: Eric Dumazet <edumazet@kernel.org>,
"David S . Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>
Cc: Simon Horman <horms@kernel.org>,
Willem de Bruijn <willemb@google.com>,
Ido Schimmel <idosch@nvidia.com>,
netdev@vger.kernel.org, edumazet@google.com
Subject: Re: [PATCH net 2/2] ipv4: reserve one IP ID per segment for UDP GSO packets
Date: Wed, 30 Sep 2026 06:28:59 -0600 [thread overview]
Message-ID: <a6f0e657-8674-4216-a1aa-88045c19643b@kernel.org> (raw)
In-Reply-To: <20260929131247.401104-3-edumazet@kernel.org>
On 9/29/26 8:12 AM, Eric Dumazet wrote:
> @@ -1464,7 +1465,19 @@ struct sk_buff *__ip_make_skb(struct sock *sk,
> iph->ttl = ttl;
> iph->protocol = sk->sk_protocol;
> ip_copy_addrs(iph, fl4);
> - ip_select_ident(net, skb, sk);
> +
> + /* UDP GSO packets are segmented later (see udp_send_skb()):
> + * reserve one IP ID per segment.
> + */
> + segs = 1;
> + if (cork->gso_size) {
> + int datalen = skb->len - skb_transport_offset(skb) -
> + sizeof(struct udphdr);
hard coding a specific transport header in L3 code is crossing layers.
> +
> + if (datalen > cork->gso_size)
> + segs = DIV_ROUND_UP(datalen, cork->gso_size);
> + }
> + ip_select_ident_segs(net, skb, sk, segs);
>
> if (opt) {
> iph->ihl += opt->optlen >> 2;
next prev parent reply other threads:[~2026-09-30 12:29 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-29 13:12 [PATCH net 0/2] ipv4: fix IP ID reuse for GSO packets Eric Dumazet
2026-09-29 13:12 ` [PATCH net 1/2] ipv4: fix IP ID reuse in ip_select_ident_segs() Eric Dumazet
2026-09-30 6:20 ` Jiayuan Chen
2026-09-30 12:30 ` David Ahern
2026-09-29 13:12 ` [PATCH net 2/2] ipv4: reserve one IP ID per segment for UDP GSO packets Eric Dumazet
2026-09-30 6:18 ` Jiayuan Chen
2026-09-30 12:28 ` David Ahern [this message]
2026-09-30 12:58 ` Eric Dumazet
2026-09-30 13:50 ` David Ahern
2026-09-30 14:24 ` Eric Dumazet
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