@@ -429,17 +429,49 @@ dp_packet_size(const struct dp_packet *b)
static inline void
dp_packet_set_size(struct dp_packet *b, uint32_t v)
{
- /* netdev-dpdk does not currently support segmentation; consequently, for
- * all intents and purposes, 'data_len' (16 bit) and 'pkt_len' (32 bit) may
- * be used interchangably.
- *
- * On the datapath, it is expected that the size of packets
- * (and thus 'v') will always be <= UINT16_MAX; this means that there is no
- * loss of accuracy in assigning 'v' to 'data_len'.
- */
- b->mbuf.data_len = (uint16_t)v; /* Current seg length. */
- b->mbuf.pkt_len = v; /* Total length of all segments linked to
- * this segment. */
+ if (b->source == DPBUF_DPDK) {
+ struct rte_mbuf *mbuf = &b->mbuf;
+ uint16_t new_len = v;
+ uint16_t data_len;
+ uint16_t nb_segs = 0;
+ uint16_t pkt_len = 0;
+
+ /* Trim 'v' length bytes from the end of the chained buffers, freeing
+ any buffers that may be left floating */
+ while (mbuf) {
+ data_len = MIN(new_len, mbuf->data_len);
+ mbuf->data_len = data_len;
+
+ if (new_len - data_len <= 0) {
+ /* Free the rest of chained mbufs */
+ free_dpdk_buf(CONTAINER_OF(mbuf->next, struct dp_packet,
+ mbuf));
+ mbuf->next = NULL;
+ } else if (!mbuf->next) {
+ /* Don't assign more than what we have available */
+ mbuf->data_len = MIN(new_len,
+ mbuf->buf_len - mbuf->data_off);
+ }
+
+ new_len -= data_len;
+ nb_segs += 1;
+ pkt_len += mbuf->data_len;
+ mbuf = mbuf->next;
+ }
+
+ /* pkt_len != v would effectively mean that pkt_len < than 'v' (as
+ * being bigger is logically impossible). Being < than 'v' would mean
+ * the 'v' provided was bigger than the available room, which is the
+ * responsibility of the caller to make sure there is enough room */
+ ovs_assert(pkt_len == v);
+
+ b->mbuf.nb_segs = nb_segs;
+ b->mbuf.pkt_len = pkt_len;
+ } else {
+ b->mbuf.data_len = v;
+ /* Total length of all segments linked to this segment. */
+ b->mbuf.pkt_len = v;
+ }
}
static inline uint16_t
@@ -451,7 +483,27 @@ __packet_data(const struct dp_packet *b)
static inline void
__packet_set_data(struct dp_packet *b, uint16_t v)
{
- b->mbuf.data_off = v;
+ if (b->source == DPBUF_DPDK) {
+ /* Moving data_off away from the first mbuf in the chain is not a
+ * possibility using DPBUF_DPDK dp_packets */
+ ovs_assert(v == UINT16_MAX || v <= b->mbuf.buf_len);
+
+ uint16_t prev_ofs = b->mbuf.data_off;
+ b->mbuf.data_off = v;
+ int16_t ofs_diff = prev_ofs - b->mbuf.data_off;
+
+ /* When dealing with DPDK mbufs, keep data_off and data_len in sync.
+ * Thus, update data_len if the length changes with the move of
+ * data_off. However, if data_len is 0, there's no data to move and
+ * data_len should remain 0. */
+
+ if (b->mbuf.data_len != 0) {
+ b->mbuf.data_len = MIN(b->mbuf.data_len + ofs_diff,
+ b->mbuf.buf_len - b->mbuf.data_off);
+ }
+ } else {
+ b->mbuf.data_off = v;
+ }
}
static inline uint16_t