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;
}