[dpdk-dev] [PATCH v4 4/5] gso: add GRE GSO support

Tan, Jianfeng jianfeng.tan at intel.com
Wed Sep 20 04:53:53 CEST 2017


Hi,


On 9/19/2017 3:32 PM, Jiayu Hu wrote:
> From: Mark Kavanagh <mark.b.kavanagh at intel.com>
>
> This patch adds GSO support for GRE-tunneled packets. Supported GRE
> packets must contain an outer IPv4 header, and inner TCP/IPv4 headers.
> They may also contain a single VLAN tag. GRE GSO doesn't check if all
> input packets have correct checksums and doesn't update checksums for
> output packets. Additionally, it doesn't process IP fragmented packets.
>
> As with VxLAN GSO, GRE GSO uses a two-segment MBUF to organize each
> output packet, which requires multi-segment mbuf support in the TX
> functions of the NIC driver. Also, if a packet is GSOed, GRE GSO reduces
> its MBUF refcnt by 1. As a result, when all of its GSOed segments are
> freed, the packet is freed automatically.
>
> GRE GSO clears the PKT_TX_TCP_SEG flag for the input packet and GSO
> segments on the event of success.
>
> Signed-off-by: Mark Kavanagh <mark.b.kavanagh at intel.com>
> Signed-off-by: Jiayu Hu <jiayu.hu at intel.com>
> ---
>   doc/guides/rel_notes/release_17_11.rst |  3 +++
>   lib/librte_gso/gso_common.c            | 31 +++++++++++++++++++++++++++++++
>   lib/librte_gso/gso_common.h            | 25 +++++++++++++++++++++++++
>   lib/librte_gso/gso_tunnel_tcp4.c       |  2 ++
>   lib/librte_gso/rte_gso.c               |  8 +++++---
>   5 files changed, 66 insertions(+), 3 deletions(-)
>
> diff --git a/doc/guides/rel_notes/release_17_11.rst b/doc/guides/rel_notes/release_17_11.rst
> index 2dc6b89..119f662 100644
> --- a/doc/guides/rel_notes/release_17_11.rst
> +++ b/doc/guides/rel_notes/release_17_11.rst
> @@ -51,6 +51,9 @@ New Features
>     * VxLAN packets, which must have an outer IPv4 header (prepended by
>       an optional VLAN tag), and contain an inner TCP/IPv4 packet (with
>       an optional VLAN tag).
> +  * GRE packets, which must contain an outer IPv4 header (prepended by
> +    an optional VLAN tag), and inner TCP/IPv4 headers (with an optional
> +    VLAN tag).
>   
>     The GSO library doesn't check if the input packets have correct
>     checksums, and doesn't update checksums for output packets.
> diff --git a/lib/librte_gso/gso_common.c b/lib/librte_gso/gso_common.c
> index 90fcb2a..3629625 100644
> --- a/lib/librte_gso/gso_common.c
> +++ b/lib/librte_gso/gso_common.c
> @@ -37,6 +37,7 @@
>   #include <rte_memcpy.h>
>   #include <rte_mempool.h>
>   #include <rte_ether.h>
> +#include <rte_gre.h>
>   #include <rte_ip.h>
>   #include <rte_tcp.h>
>   #include <rte_udp.h>
> @@ -258,3 +259,33 @@ update_ipv4_vxlan_tcp4_header(struct rte_mbuf *pkt, uint8_t ipid_delta,
>   		sent_seq += (segs[i]->pkt_len - segs[i]->data_len);
>   	}
>   }
> +
> +void
> +update_ipv4_gre_tcp4_header(struct rte_mbuf *pkt, uint8_t ipid_delta,
> +		struct rte_mbuf **segs, uint16_t nb_segs)
> +{

This function seems to have too many duplicated code with above 
function, can we merge?

> +	struct ipv4_hdr *ipv4_hdr;
> +	struct tcp_hdr *tcp_hdr;
> +	uint32_t sent_seq;
> +	uint16_t l2_len, outer_id, inner_id, tail_idx, i;
> +
> +	ipv4_hdr = (struct ipv4_hdr *)(rte_pktmbuf_mtod(pkt, char *) +
> +			pkt->outer_l2_len);
> +	outer_id = rte_be_to_cpu_16(ipv4_hdr->packet_id);
> +
> +	l2_len = pkt->outer_l2_len + pkt->outer_l3_len + pkt->l2_len;
> +	ipv4_hdr = (struct ipv4_hdr *)(rte_pktmbuf_mtod(pkt, char *) + l2_len);
> +	inner_id = rte_be_to_cpu_16(ipv4_hdr->packet_id);
> +	tcp_hdr = (struct tcp_hdr *)((char *)ipv4_hdr + pkt->l3_len);
> +	sent_seq = rte_be_to_cpu_32(tcp_hdr->sent_seq);
> +	tail_idx = nb_segs - 1;
> +	for (i = 0; i < nb_segs; i++) {
> +		__update_outer_ipv4_header(segs[i], outer_id);
> +		outer_id += ipid_delta;

We should update both outer and inner IPID? Could you add some spec 
reference here?

> +
> +		__update_ipv4_tcp_header(segs[i], l2_len, inner_id, sent_seq,
> +				i < tail_idx);
> +		inner_id += ipid_delta;
> +		sent_seq += (segs[i]->pkt_len - segs[i]->data_len);
> +	}
> +}
> diff --git a/lib/librte_gso/gso_common.h b/lib/librte_gso/gso_common.h
> index 0b0d8ed..433e952 100644
> --- a/lib/librte_gso/gso_common.h
> +++ b/lib/librte_gso/gso_common.h
> @@ -53,6 +53,11 @@
>   		(PKT_TX_TCP_SEG | PKT_TX_IPV4 | PKT_TX_OUTER_IPV4 | \
>   		 PKT_TX_TUNNEL_VXLAN))
>   
> +#define IS_IPV4_GRE_TCP4(flag) (((flag) & (PKT_TX_TCP_SEG | PKT_TX_IPV4 | \
> +				PKT_TX_OUTER_IPV4 | PKT_TX_TUNNEL_GRE)) == \
> +		(PKT_TX_TCP_SEG | PKT_TX_IPV4 | PKT_TX_OUTER_IPV4 | \
> +		 PKT_TX_TUNNEL_GRE))
> +
>   /**
>    * Internal function which updates relevant packet headers for TCP/IPv4
>    * packets, following segmentation. This is required to update, for
> @@ -94,6 +99,26 @@ void update_ipv4_vxlan_tcp4_header(struct rte_mbuf *pkt,
>   		uint16_t nb_segs);
>   
>   /**
> + * Internal function which updates relevant packet headers for GRE
> + * packets, following segmentation. This is required to update, for
> + * example, the IPv4 'total_length' field, to reflect the reduced
> + * length of the now-segmented packet.
> + *
> + * @param pkt
> + *  The original packet.
> + * @param ipid_delta
> + *  The increasing uint of IP ids.

uint -> unit?

> + * @param segs
> + *  Pointer array used for storing mbuf addresses for GSO segments.
> + * @param nb_segs
> + *  The number of GSO segments placed in segs.
> + */
> +void update_ipv4_gre_tcp4_header(struct rte_mbuf *pkt,
> +		uint8_t ipid_delta,
> +		struct rte_mbuf **segs,
> +		uint16_t nb_segs);
> +
> +/**
>    * Internal function which divides the input packet into small segments.
>    * Each of the newly-created segments is organized as a two-segment MBUF,
>    * where the first segment is a standard mbuf, which stores a copy of
> diff --git a/lib/librte_gso/gso_tunnel_tcp4.c b/lib/librte_gso/gso_tunnel_tcp4.c
> index cc017bd..5d5930a 100644
> --- a/lib/librte_gso/gso_tunnel_tcp4.c
> +++ b/lib/librte_gso/gso_tunnel_tcp4.c
> @@ -82,6 +82,8 @@ gso_tunnel_tcp4_segment(struct rte_mbuf *pkt,
>   
>   	if (pkt->ol_flags & PKT_TX_TUNNEL_VXLAN)
>   		update_ipv4_vxlan_tcp4_header(pkt, ipid_delta, pkts_out, ret);
> +	else if (pkt->ol_flags & PKT_TX_TUNNEL_GRE)
> +		update_ipv4_gre_tcp4_header(pkt, ipid_delta, pkts_out, ret);
>   
>   	return ret;
>   }
> diff --git a/lib/librte_gso/rte_gso.c b/lib/librte_gso/rte_gso.c
> index d1a723b..5464831 100644
> --- a/lib/librte_gso/rte_gso.c
> +++ b/lib/librte_gso/rte_gso.c
> @@ -60,8 +60,9 @@ rte_gso_segment(struct rte_mbuf *pkt,
>   
>   	if ((gso_ctx->gso_size >= pkt->pkt_len) || (gso_ctx->gso_types &
>   				(DEV_TX_OFFLOAD_TCP_TSO |
> -				 DEV_TX_OFFLOAD_VXLAN_TNL_TSO)) !=
> -				gso_ctx->gso_types) {
> +				 DEV_TX_OFFLOAD_VXLAN_TNL_TSO |
> +				 DEV_TX_OFFLOAD_GRE_TNL_TSO)) !=
> +				 gso_ctx->gso_types) {
>   		pkt->ol_flags &= (~PKT_TX_TCP_SEG);
>   		pkts_out[0] = pkt;
>   		return ret;
> @@ -73,7 +74,8 @@ rte_gso_segment(struct rte_mbuf *pkt,
>   	ipid_delta = (gso_ctx->ipid_flag != RTE_GSO_IPID_FIXED);
>   	ol_flags = pkt->ol_flags;
>   
> -	if (IS_IPV4_VXLAN_TCP4(pkt->ol_flags)) {
> +	if (IS_IPV4_VXLAN_TCP4(pkt->ol_flags) ||
> +			IS_IPV4_GRE_TCP4(pkt->ol_flags)) {
>   		pkt->ol_flags &= (~PKT_TX_TCP_SEG);
>   		ret = gso_tunnel_tcp4_segment(pkt, gso_size, ipid_delta,
>   				direct_pool, indirect_pool,



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