2017/11/08_OVS+DPDK封包處理流程追蹤

Struct flow

    /* L3 (64-bit aligned) */

    ovs_be32 nw_src;            /* IPv4 source address or ARP SPA. */

    ovs_be32 nw_dst;            /* IPv4 destination address or ARP TPA. */

#define IP_HEADER_LEN 20

struct ip_header {

    uint8_t ip_ihl_ver;

    uint8_t ip_tos;

    ovs_be16 ip_tot_len;

    ovs_be16 ip_id;

    ovs_be16 ip_frag_off;

    uint8_t ip_ttl;

    uint8_t ip_proto;

    ovs_be16 ip_csum;

    ovs_16aligned_be32 ip_src;

    ovs_16aligned_be32 ip_dst;

};

    /* Network layer. */

    packet->l3_ofs = (char *)data - l2;

    nw_frag = 0;

    if (OVS_LIKELY(dl_type == htons(ETH_TYPE_IP))) {

        const struct ip_header *nh = data;

        int ip_len;

        uint16_t tot_len;

        if (OVS_UNLIKELY(size < IP_HEADER_LEN)) {

            goto out;

        }

        ip_len = IP_IHL(nh->ip_ihl_ver) * 4;

        if (OVS_UNLIKELY(ip_len < IP_HEADER_LEN)) {

            goto out;

        }

        if (OVS_UNLIKELY(size < ip_len)) {

            goto out;

        }

        tot_len = ntohs(nh->ip_tot_len);

        if (OVS_UNLIKELY(tot_len > size || ip_len > tot_len)) {

            goto out;

        }

        if (OVS_UNLIKELY(size - tot_len > UINT8_MAX)) {

            goto out;

        }

        dp_packet_set_l2_pad_size(packet, size - tot_len);

        size = tot_len;   /* Never pull padding. */

        /* Push both source and destination address at once. */

        miniflow_push_words(mf, nw_src, &nh->ip_src, 1);

        miniflow_push_be32(mf, ipv6_label, 0); /* Padding for IPv4. */

        nw_tos = nh->ip_tos;

        nw_ttl = nh->ip_ttl;

        nw_proto = nh->ip_proto;

        if (OVS_UNLIKELY(IP_IS_FRAGMENT(nh->ip_frag_off))) {

            nw_frag = FLOW_NW_FRAG_ANY;

            if (nh->ip_frag_off & htons(IP_FRAG_OFF_MASK)) {

                nw_frag |= FLOW_NW_FRAG_LATER;

            }

        }

        data_pull(&data, &size, ip_len);

#632 miniflow_extract(struct dp_packet *packet, struct miniflow *dst)

#306 #define miniflow_push_words(MF, FIELD, VALUEP, N_WORDS)                 \

#307 miniflow_push_words_(MF, offsetof(struct flow, FIELD), VALUEP, N_WORDS)

＃1985  miniflow_hash_5tuple(const struct miniflow *flow, uint32_t basis)

＃2006  hash = hash_add(hash, MINIFLOW_GET_U32(flow, nw_src));

 #define IP_HEADER_LEN 20

struct ip_header {

    uint8_t ip_ihl_ver;

    uint8_t ip_tos;

    ovs_be16 ip_tot_len;

    ovs_be16 ip_id;

    ovs_be16 ip_frag_off;

    uint8_t ip_ttl;

    uint8_t ip_proto;

    ovs_be16 ip_csum;

    ovs_16aligned_be32 ip_src;

    ovs_16aligned_be32 ip_dst;

};