rte_pktmbuf_linearize

static inline int
rte_pktmbuf_linearize(struct rte_mbuf *mbuf)
{
        if (rte_pktmbuf_is_contiguous(mbuf))
                return 0;
        return __rte_pktmbuf_linearize(mbuf);
}

/**
 * Test if mbuf data is contiguous.
 *
 * @param m
 *   The packet mbuf.
 * @return
 *   - 1, if all data is contiguous (one segment).
 *   - 0, if there is several segments.
 */
static inline int rte_pktmbuf_is_contiguous(const struct rte_mbuf *m)
{
        __rte_mbuf_sanity_check(m, 1);
        return !!(m->nb_segs == 1);
}

__rte_pktmbuf_linearize(struct rte_mbuf *mbuf)
{
        size_t seg_len, copy_len;
        struct rte_mbuf *m;
        struct rte_mbuf *m_next;
        char *buffer;

        /* Extend first segment to the total packet length */
        copy_len = rte_pktmbuf_pkt_len(mbuf) - rte_pktmbuf_data_len(mbuf);

        if (unlikely(copy_len > rte_pktmbuf_tailroom(mbuf)))
                return -1;

        buffer = rte_pktmbuf_mtod_offset(mbuf, char *, mbuf->data_len);
        mbuf->data_len = (uint16_t)(mbuf->pkt_len);

        /* Append data from next segments to the first one */
        m = mbuf->next;
        while (m != NULL) {
                m_next = m->next;

                seg_len = rte_pktmbuf_data_len(m);
                rte_memcpy(buffer, rte_pktmbuf_mtod(m, char *), seg_len);
                buffer += seg_len;

                rte_pktmbuf_free_seg(m);
                m = m_next;
        }

        mbuf->next = NULL;
        mbuf->nb_segs = 1;

        return 0;
}

static inline uint16_t rte_pktmbuf_headroom(const struct rte_mbuf *m)
{
        __rte_mbuf_sanity_check(m, 0);
        return m->data_off;
}

/**
 * Get the tailroom of a packet mbuf.
 *
 * @param m
 *   The packet mbuf.
 * @return
 *   The length of the tailroom.
 */
static inline uint16_t rte_pktmbuf_tailroom(const struct rte_mbuf *m)
{
        __rte_mbuf_sanity_check(m, 0);
        return (uint16_t)(m->buf_len - rte_pktmbuf_headroom(m) -
                          m->data_len);
}