examples/tep_termination/vxlan.c

/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright(c) 2010-2015 Intel Corporation
 */

#include <stdint.h>
#include <rte_mbuf.h>
#include <rte_hash_crc.h>
#include <rte_byteorder.h>
#include <rte_udp.h>
#include <rte_tcp.h>
#include <rte_sctp.h>

#include "main.h"
#include "vxlan.h"

static uint16_t
get_psd_sum(void *l3_hdr, uint16_t ethertype, uint64_t ol_flags)
{
        if (ethertype == ETHER_TYPE_IPv4)
                return rte_ipv4_phdr_cksum(l3_hdr, ol_flags);
        else /* assume ethertype == ETHER_TYPE_IPv6 */
                return rte_ipv6_phdr_cksum(l3_hdr, ol_flags);
}

static void
parse_ethernet(struct ether_hdr *eth_hdr, union tunnel_offload_info *info,
                uint8_t *l4_proto)
{
        struct ipv4_hdr *ipv4_hdr;
        struct ipv6_hdr *ipv6_hdr;
        uint16_t ethertype;

        info->outer_l2_len = sizeof(struct ether_hdr);
        ethertype = rte_be_to_cpu_16(eth_hdr->ether_type);

        if (ethertype == ETHER_TYPE_VLAN) {
                struct vlan_hdr *vlan_hdr = (struct vlan_hdr *)(eth_hdr + 1);
                info->outer_l2_len  += sizeof(struct vlan_hdr);
                ethertype = rte_be_to_cpu_16(vlan_hdr->eth_proto);
        }

        switch (ethertype) {
        case ETHER_TYPE_IPv4:
                ipv4_hdr = (struct ipv4_hdr *)
                        ((char *)eth_hdr + info->outer_l2_len);
                info->outer_l3_len = sizeof(struct ipv4_hdr);
                *l4_proto = ipv4_hdr->next_proto_id;
                break;
        case ETHER_TYPE_IPv6:
                ipv6_hdr = (struct ipv6_hdr *)
                        ((char *)eth_hdr + info->outer_l2_len);
                info->outer_l3_len = sizeof(struct ipv6_hdr);
                *l4_proto = ipv6_hdr->proto;
                break;
        default:
                info->outer_l3_len = 0;
                *l4_proto = 0;
                break;
        }
}

static uint64_t
process_inner_cksums(struct ether_hdr *eth_hdr, union tunnel_offload_info *info)
{
        void *l3_hdr = NULL;
        uint8_t l4_proto;
        uint16_t ethertype;
        struct ipv4_hdr *ipv4_hdr;
        struct ipv6_hdr *ipv6_hdr;
        struct udp_hdr *udp_hdr;
        struct tcp_hdr *tcp_hdr;
        struct sctp_hdr *sctp_hdr;
        uint64_t ol_flags = 0;

        info->l2_len = sizeof(struct ether_hdr);
        ethertype = rte_be_to_cpu_16(eth_hdr->ether_type);

        if (ethertype == ETHER_TYPE_VLAN) {
                struct vlan_hdr *vlan_hdr = (struct vlan_hdr *)(eth_hdr + 1);
                info->l2_len  += sizeof(struct vlan_hdr);
                ethertype = rte_be_to_cpu_16(vlan_hdr->eth_proto);
        }

        l3_hdr = (char *)eth_hdr + info->l2_len;

        if (ethertype == ETHER_TYPE_IPv4) {
                ipv4_hdr = (struct ipv4_hdr *)l3_hdr;
                ipv4_hdr->hdr_checksum = 0;
                ol_flags |= PKT_TX_IPV4;
                ol_flags |= PKT_TX_IP_CKSUM;
                info->l3_len = sizeof(struct ipv4_hdr);
                l4_proto = ipv4_hdr->next_proto_id;
        } else if (ethertype == ETHER_TYPE_IPv6) {
                ipv6_hdr = (struct ipv6_hdr *)l3_hdr;
                info->l3_len = sizeof(struct ipv6_hdr);
                l4_proto = ipv6_hdr->proto;
                ol_flags |= PKT_TX_IPV6;
        } else
                return 0; /* packet type not supported, nothing to do */

        if (l4_proto == IPPROTO_UDP) {
                udp_hdr = (struct udp_hdr *)((char *)l3_hdr + info->l3_len);
                ol_flags |= PKT_TX_UDP_CKSUM;
                udp_hdr->dgram_cksum = get_psd_sum(l3_hdr,
                                ethertype, ol_flags);
        } else if (l4_proto == IPPROTO_TCP) {
                tcp_hdr = (struct tcp_hdr *)((char *)l3_hdr + info->l3_len);
                /* Put PKT_TX_TCP_SEG bit setting before get_psd_sum(), because
                 * it depends on PKT_TX_TCP_SEG to calculate pseudo-header
                 * checksum.
                 */
                if (tso_segsz != 0) {
                        ol_flags |= PKT_TX_TCP_SEG;
                        info->tso_segsz = tso_segsz;
                        info->l4_len = (tcp_hdr->data_off & 0xf0) >> 2;
                }
                ol_flags |= PKT_TX_TCP_CKSUM;
                tcp_hdr->cksum = get_psd_sum(l3_hdr, ethertype, ol_flags);

        } else if (l4_proto == IPPROTO_SCTP) {
                sctp_hdr = (struct sctp_hdr *)((char *)l3_hdr + info->l3_len);
                sctp_hdr->cksum = 0;
                ol_flags |= PKT_TX_SCTP_CKSUM;
        }

        return ol_flags;
}

int
decapsulation(struct rte_mbuf *pkt)
{
        uint8_t l4_proto = 0;
        uint16_t outer_header_len;
        struct udp_hdr *udp_hdr;
        union tunnel_offload_info info = { .data = 0 };
        struct ether_hdr *phdr = rte_pktmbuf_mtod(pkt, struct ether_hdr *);

        parse_ethernet(phdr, &info, &l4_proto);

        if (l4_proto != IPPROTO_UDP)
                return -1;

        udp_hdr = (struct udp_hdr *)((char *)phdr +
                info.outer_l2_len + info.outer_l3_len);

        if (udp_hdr->dst_port != rte_cpu_to_be_16(DEFAULT_VXLAN_PORT) &&
                (pkt->packet_type & RTE_PTYPE_TUNNEL_MASK) == 0)
                return -1;
        outer_header_len = info.outer_l2_len + info.outer_l3_len
                + sizeof(struct udp_hdr) + sizeof(struct vxlan_hdr);

        rte_pktmbuf_adj(pkt, outer_header_len);

        return 0;
}

void
encapsulation(struct rte_mbuf *m, uint8_t queue_id)
{
        uint vport_id;
        uint64_t ol_flags = 0;
        uint32_t old_len = m->pkt_len, hash;
        union tunnel_offload_info tx_offload = { .data = 0 };
        struct ether_hdr *phdr = rte_pktmbuf_mtod(m, struct ether_hdr *);

        /*Allocate space for new ethernet, IPv4, UDP and VXLAN headers*/
        struct ether_hdr *pneth = (struct ether_hdr *) rte_pktmbuf_prepend(m,
                sizeof(struct ether_hdr) + sizeof(struct ipv4_hdr)
                + sizeof(struct udp_hdr) + sizeof(struct vxlan_hdr));

        struct ipv4_hdr *ip = (struct ipv4_hdr *) &pneth[1];
        struct udp_hdr *udp = (struct udp_hdr *) &ip[1];
        struct vxlan_hdr *vxlan = (struct vxlan_hdr *) &udp[1];

        /* convert TX queue ID to vport ID */
        vport_id = queue_id - 1;

        /* replace original Ethernet header with ours */
        pneth = rte_memcpy(pneth, &app_l2_hdr[vport_id],
                sizeof(struct ether_hdr));

        /* copy in IP header */
        ip = rte_memcpy(ip, &app_ip_hdr[vport_id],
                sizeof(struct ipv4_hdr));
        ip->total_length = rte_cpu_to_be_16(m->pkt_len
                                - sizeof(struct ether_hdr));

        /* outer IP checksum */
        ol_flags |= PKT_TX_OUTER_IP_CKSUM;
        ip->hdr_checksum = 0;

        /* inner IP checksum offload */
        if (tx_checksum) {
                ol_flags |= process_inner_cksums(phdr, &tx_offload);
                m->l2_len = tx_offload.l2_len;
                m->l3_len = tx_offload.l3_len;
                m->l4_len = tx_offload.l4_len;
                m->l2_len += ETHER_VXLAN_HLEN;
        }

        m->outer_l2_len = sizeof(struct ether_hdr);
        m->outer_l3_len = sizeof(struct ipv4_hdr);

        ol_flags |= PKT_TX_TUNNEL_VXLAN;

        m->ol_flags |= ol_flags;
        m->tso_segsz = tx_offload.tso_segsz;

        /*VXLAN HEADER*/
        vxlan->vx_flags = rte_cpu_to_be_32(VXLAN_HF_VNI);
        vxlan->vx_vni = rte_cpu_to_be_32(vxdev.out_key << 8);

        /*UDP HEADER*/
        udp->dgram_cksum = 0;
        udp->dgram_len = rte_cpu_to_be_16(old_len
                                + sizeof(struct udp_hdr)
                                + sizeof(struct vxlan_hdr));

        udp->dst_port = rte_cpu_to_be_16(vxdev.dst_port);
        hash = rte_hash_crc(phdr, 2 * ETHER_ADDR_LEN, phdr->ether_type);
        udp->src_port = rte_cpu_to_be_16((((uint64_t) hash * PORT_RANGE) >> 32)
                                        + PORT_MIN);

        return;
}