Prior to this commit IP/UDP/TCP checksum offload calculations
were skipped in case of a multi segments packet.
This commit enables TAP checksum calculations for multi segments
packets.
The only restriction is that the first segment must contain all
headers of layers 2, 3 and 4 (where layer 4 header size equals
TCP header size).
Signed-off-by: Ophir Munk <ophi...@mellanox.com>
---
drivers/net/tap/rte_eth_tap.c | 54 ++++++++++++++++++++++++++++++++-----------
1 file changed, 40 insertions(+), 14 deletions(-)
diff --git a/drivers/net/tap/rte_eth_tap.c b/drivers/net/tap/rte_eth_tap.c
index 61d6465..df23c4d 100644
--- a/drivers/net/tap/rte_eth_tap.c
+++ b/drivers/net/tap/rte_eth_tap.c
@@ -509,6 +509,10 @@ pmd_tx_burst(void *queue, struct rte_mbuf **bufs, uint16_t
nb_pkts)
char m_copy[mbuf->data_len];
int n;
int j;
+ int k; /* first index in iovecs for copying segments */
+ uint16_t l234_len; /* length of layers 2,3,4 headers */
+ uint16_t seg_len; /* length of first segment */
+ uint16_t nb_segs;
/* stats.errs will be incremented */
if (rte_pktmbuf_pkt_len(mbuf) > max_size)
@@ -529,30 +533,52 @@ pmd_tx_burst(void *queue, struct rte_mbuf **bufs,
uint16_t nb_pkts)
if (j & (0x40 | 0x60))
pi.proto = (j == 0x40) ? 0x0008 : 0xdd86;
- iovecs[0].iov_base = π
- iovecs[0].iov_len = sizeof(pi);
- for (j = 1; j <= mbuf->nb_segs; j++) {
- iovecs[j].iov_len = rte_pktmbuf_data_len(seg);
- iovecs[j].iov_base =
- rte_pktmbuf_mtod(seg, void *);
- seg = seg->next;
- }
+ k = 0;
+ iovecs[k].iov_base = π
+ iovecs[k].iov_len = sizeof(pi);
+ k++;
+ nb_segs = mbuf->nb_segs;
if (txq->csum &&
((mbuf->ol_flags & (PKT_TX_IP_CKSUM | PKT_TX_IPV4) ||
(mbuf->ol_flags & PKT_TX_L4_MASK) == PKT_TX_UDP_CKSUM ||
(mbuf->ol_flags & PKT_TX_L4_MASK) == PKT_TX_TCP_CKSUM))) {
- /* Support only packets with all data in the same seg */
- if (mbuf->nb_segs > 1)
+ /* Support only packets with at least layer 4
+ * header included in the first segment
+ */
+ seg_len = rte_pktmbuf_data_len(mbuf);
+ l234_len = mbuf->l2_len + mbuf->l3_len +
+ sizeof(struct tcp_hdr);
+ if (seg_len < l234_len)
break;
- /* To change checksums, work on a copy of data. */
+
+ /* To change checksums, work on a
+ * copy of l2, l3 l4 headers.
+ */
rte_memcpy(m_copy, rte_pktmbuf_mtod(mbuf, void *),
- rte_pktmbuf_data_len(mbuf));
+ l234_len);
tap_tx_offload(m_copy, mbuf->ol_flags,
mbuf->l2_len, mbuf->l3_len);
- iovecs[1].iov_base = m_copy;
+ iovecs[k].iov_base = m_copy;
+ iovecs[k].iov_len = l234_len;
+ k++;
+ /* Update next iovecs[] beyond l2, l3, l4 headers */
+ if (seg_len > l234_len) {
+ iovecs[k].iov_len = seg_len - l234_len;
+ iovecs[k].iov_base =
+ rte_pktmbuf_mtod(seg, char *) +
+ l234_len;
+ k++;
+ }
+ nb_segs--;
+ seg = seg->next;
+ }
+ for (j = k; j <= nb_segs; j++) {
+ iovecs[j].iov_len = rte_pktmbuf_data_len(seg);
+ iovecs[j].iov_base = rte_pktmbuf_mtod(seg, void *);
+ seg = seg->next;
}
/* copy the tx frame data */
- n = writev(txq->fd, iovecs, mbuf->nb_segs + 1);
+ n = writev(txq->fd, iovecs, j);
if (n <= 0)
break;
--
2.7.4
