udp: support sctp over udp in skb_udp_tunnel_segment (527beb8e) · Commits · 戴 / test

For the gso of sctp over udp packets, sctp_gso_segment() will be called in skb_udp_tunnel_segment(), we need to set transport_header to sctp header. As all the current HWs can't handle both crc checksum and udp checksum at the same time, the crc checksum has to be done in sctp_gso_segment() by removing the NETIF_F_SCTP_CRC flag from the features. Meanwhile, if the HW can't do udp checksum, csum and csum_start has to be set correctly, and udp checksum will be done in __skb_udp_tunnel_segment() by calling gso_make_checksum(). Thanks to Paolo, Marcelo and Guillaume for helping with this one. v1->v2: - no change. v2->v3: - remove the he NETIF_F_SCTP_CRC flag from the features. - set csum and csum_start in sctp_gso_make_checksum(). Signed-off-by:

Xin Long <lucien.xin@gmail.com> Acked-by:

Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by:

Jakub Kicinski <kuba@kernel.org>

net/ipv4/udp_offload.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -49,6 +49,7 @@ static struct sk_buff __skb_udp_tunnel_segment(struct sk_buff skb,
		__skb_pull(skb, tnl_hlen);
		skb_reset_mac_header(skb);
		skb_set_network_header(skb, skb_inner_network_offset(skb));
		skb_set_transport_header(skb, skb_inner_transport_offset(skb));
		skb->mac_len = skb_inner_network_offset(skb);
		skb->protocol = new_protocol;

		@@ -67,6 +68,8 @@ static struct sk_buff __skb_udp_tunnel_segment(struct sk_buff skb,
		(NETIF_F_HW_CSUM \| NETIF_F_IP_CSUM))));

		features &= skb->dev->hw_enc_features;
		/* CRC checksum can't be handled by HW when it's a UDP tunneling packet. */
		features &= ~NETIF_F_SCTP_CRC;

		/* The only checksum offload we care about from here on out is the
		* outer one so strip the existing checksum feature flags and

net/sctp/offload.c

+5 −1

Original line number	Diff line number	Diff line
		@@ -27,7 +27,11 @@ static __le32 sctp_gso_make_checksum(struct sk_buff *skb)
		{
		skb->ip_summed = CHECKSUM_NONE;
		skb->csum_not_inet = 0;
		gso_reset_checksum(skb, ~0);
		/* csum and csum_start in GSO CB may be needed to do the UDP
		* checksum when it's a UDP tunneling packet.
		*/
		SKB_GSO_CB(skb)->csum = (__force __wsum)~0;
		SKB_GSO_CB(skb)->csum_start = skb_headroom(skb) + skb->len;
		return sctp_compute_cksum(skb, skb_transport_offset(skb));
		}

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