RE: [DPDK/ethdev Bug 1416] net/af_packet: tx_burst() can modify packets

[Konstantin Ananyev <konstantin.ananyev@huawei.com>]

> 
> > static uint16_t
> > eth_af_packet_tx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
> > {
> >         ...
> >         for (i = 0; i < nb_pkts; i++) {
> >                 mbuf = *bufs++;
> >
> >                 ...
> >
> >                 /* insert vlan info if necessary */
> >                 if (mbuf->ol_flags & RTE_MBUF_F_TX_VLAN) {
> >                         if (rte_vlan_insert(&mbuf)) {
> >                                 rte_pktmbuf_free(mbuf);
> >                                 continue;
> >
> > AFAIU, it does copy of mbuf contents into pbuf anyway (just few line below).
> > So the fix might be - simply insert VLAN tag at copying stage.
> > Feel free to correct me, if I missed something.
> 
> vlan_insert will fail if the mbuf is has refcnt > 1.
> 
> static inline int rte_vlan_insert(struct rte_mbuf **m)
> {
> 	struct rte_ether_hdr *oh, *nh;
> 	struct rte_vlan_hdr *vh;
> 
> 	/* Can't insert header if mbuf is shared */
> 	if (!RTE_MBUF_DIRECT(*m) || rte_mbuf_refcnt_read(*m) > 1)
> 		return -EINVAL;

You are right, I missed that.
Will close it then.
Thanks
Konstantin