app/testpmd: fix eth packet dump for small buffers

In the rather unlikely case where the first segment is too small to
contain an ethernet header, we can't go and directly dereference the
mbuf data buffer.

Using rte_pktmbuf_read is a little more expensive but this is still
acceptable for a debugging feature.

Fixes: af75078fece3 ("first public release")
Cc: stable@dpdk.org
Signed-off-by: David Marchand <david.marchand@redhat.com>
Acked-by: Bernard Iremonger <bernard.iremonger@intel.com>

diff --git a/app/test-pmd/util.c b/app/test-pmd/util.c
index a1164b7..18dfdca 100644 (file)
--- a/app/test-pmd/util.c
+++ b/app/test-pmd/util.c
@@ -14,7 +14,7 @@
 #include "testpmd.h"
 
 static inline void
-print_ether_addr(const char *what, struct rte_ether_addr *eth_addr)
+print_ether_addr(const char *what, const struct rte_ether_addr *eth_addr)
 {
        char buf[RTE_ETHER_ADDR_FMT_SIZE];
        rte_ether_format_addr(buf, RTE_ETHER_ADDR_FMT_SIZE, eth_addr);
@@ -26,7 +26,8 @@ dump_pkt_burst(uint16_t port_id, uint16_t queue, struct rte_mbuf *pkts[],
              uint16_t nb_pkts, int is_rx)
 {
        struct rte_mbuf  *mb;
-       struct rte_ether_hdr *eth_hdr;
+       const struct rte_ether_hdr *eth_hdr;
+       struct rte_ether_hdr _eth_hdr;
        uint16_t eth_type;
        uint64_t ol_flags;
        uint16_t i, packet_type;
@@ -46,7 +47,7 @@ dump_pkt_burst(uint16_t port_id, uint16_t queue, struct rte_mbuf *pkts[],
               (unsigned int) nb_pkts);
        for (i = 0; i < nb_pkts; i++) {
                mb = pkts[i];
-               eth_hdr = rte_pktmbuf_mtod(mb, struct rte_ether_hdr *);
+               eth_hdr = rte_pktmbuf_read(mb, 0, sizeof(_eth_hdr), &_eth_hdr);
                eth_type = RTE_BE_TO_CPU_16(eth_hdr->ether_type);
                ol_flags = mb->ol_flags;
                packet_type = mb->packet_type;