[lng-odp] [API-NEXT PATCH v4 19/23] linux-gen: socket: use trunc instead of pull tail

[Petri Savolainen]

This is a bug correction for multi-segment packet handling. Packet
pull tail cannot decrement packet length more than there are data
in the last segment. Trunc tail must be used instead.

Signed-off-by: Petri Savolainen <petri.savolai...@nokia.com>
---
 platform/linux-generic/pktio/socket.c | 25 +++++++++++++++++++------
 1 file changed, 19 insertions(+), 6 deletions(-)

diff --git a/platform/linux-generic/pktio/socket.c 
b/platform/linux-generic/pktio/socket.c
index 9fe4a7e..7d23968 100644
--- a/platform/linux-generic/pktio/socket.c
+++ b/platform/linux-generic/pktio/socket.c
@@ -674,6 +674,7 @@ static int sock_mmsg_recv(pktio_entry_t *pktio_entry, int 
index ODP_UNUSED,
                        if (cls_classify_packet(pktio_entry, base, pkt_len,
                                                pkt_len, &pool, &parsed_hdr))
                                continue;
+
                        num = packet_alloc_multi(pool, pkt_len, &pkt, 1);
                        if (num != 1)
                                continue;
@@ -700,6 +701,7 @@ static int sock_mmsg_recv(pktio_entry_t *pktio_entry, int 
index ODP_UNUSED,
 
                        num = packet_alloc_multi(pkt_sock->pool, pkt_sock->mtu,
                                                 &pkt_table[i], 1);
+
                        if (odp_unlikely(num != 1)) {
                                pkt_table[i] = ODP_PACKET_INVALID;
                                break;
@@ -724,23 +726,34 @@ static int sock_mmsg_recv(pktio_entry_t *pktio_entry, int 
index ODP_UNUSED,
                        void *base = msgvec[i].msg_hdr.msg_iov->iov_base;
                        struct ethhdr *eth_hdr = base;
                        odp_packet_hdr_t *pkt_hdr;
+                       odp_packet_t pkt;
+                       int ret;
+
+                       pkt = pkt_table[i];
 
                        /* Don't receive packets sent by ourselves */
                        if (odp_unlikely(ethaddrs_equal(pkt_sock->if_mac,
                                                        eth_hdr->h_source))) {
-                               odp_packet_free(pkt_table[i]);
+                               odp_packet_free(pkt);
                                continue;
                        }
-                       pkt_hdr = odp_packet_hdr(pkt_table[i]);
+
                        /* Parse and set packet header data */
-                       odp_packet_pull_tail(pkt_table[i],
-                                            odp_packet_len(pkt_table[i]) -
-                                            msgvec[i].msg_len);
+                       ret = odp_packet_trunc_tail(&pkt, odp_packet_len(pkt) -
+                                                   msgvec[i].msg_len,
+                                                   NULL, NULL);
+                       if (ret < 0) {
+                               ODP_ERR("trunk_tail failed");
+                               odp_packet_free(pkt);
+                               continue;
+                       }
+
+                       pkt_hdr = odp_packet_hdr(pkt);
                        packet_parse_l2(&pkt_hdr->p, pkt_hdr->frame_len);
                        packet_set_ts(pkt_hdr, ts);
                        pkt_hdr->input = pktio_entry->s.handle;
 
-                       pkt_table[nb_rx] = pkt_table[i];
+                       pkt_table[nb_rx] = pkt;
                        nb_rx++;
                }
 
-- 
2.8.1