[v2,1/5] examples/ipsec-secgw: fix invalid packet length

  for packets smaller then 64B some NICs reports pkt_len=64B.
As ipsec-secgw (and librte_ipsec) relies on pkt_len value to determine
payload length, that causes problems for small packets.
To fix the issue, check that pkt_len matches values in IPv4/IPv6 header
and re-adjust pkt_len if necessary.

Fixes: 906257e965b7 ("examples/ipsec-secgw: support IPv6")
Fixes: d299106e8e31 ("examples/ipsec-secgw: add IPsec sample application")
Cc: stable@dpdk.org

Signed-off-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
---
 examples/ipsec-secgw/ipsec-secgw.c | 59 +++++++++++++++++++++++-------
 1 file changed, 46 insertions(+), 13 deletions(-)
  

Hi Konstantin,

Could you please rebase this patchset. There are some conflicting changes because of Marcin's patches.
Also could you please squash your doc patch with " examples/ipsec-secgw: support packet fragmentation and reassembly "
As per convention followed, there should not be separate doc patches.

Thanks,
Akhil
> 
> for packets smaller then 64B some NICs reports pkt_len=64B.
> As ipsec-secgw (and librte_ipsec) relies on pkt_len value to determine
> payload length, that causes problems for small packets.
> To fix the issue, check that pkt_len matches values in IPv4/IPv6 header
> and re-adjust pkt_len if necessary.
> 
> Fixes: 906257e965b7 ("examples/ipsec-secgw: support IPv6")
> Fixes: d299106e8e31 ("examples/ipsec-secgw: add IPsec sample application")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
> ---
>  examples/ipsec-secgw/ipsec-secgw.c | 59 +++++++++++++++++++++++-------
>  1 file changed, 46 insertions(+), 13 deletions(-)
> 
> diff --git a/examples/ipsec-secgw/ipsec-secgw.c b/examples/ipsec-
> secgw/ipsec-secgw.c
> index 6c626fa5f..4004f2bc2 100644
> --- a/examples/ipsec-secgw/ipsec-secgw.c
> +++ b/examples/ipsec-secgw/ipsec-secgw.c
> @@ -229,35 +229,68 @@ static struct rte_eth_conf port_conf = {
> 
>  static struct socket_ctx socket_ctx[NB_SOCKETS];
> 
> +static inline void
> +adjust_ipv4_pktlen(struct rte_mbuf *m, const struct rte_ipv4_hdr *iph,
> +	uint32_t l2_len)
> +{
> +	uint32_t plen, trim;
> +
> +	plen = rte_be_to_cpu_16(iph->total_length) + l2_len;
> +	if (plen < m->pkt_len) {
> +		trim = m->pkt_len - plen;
> +		rte_pktmbuf_trim(m, trim);
> +	}
> +}
> +
> +static inline void
> +adjust_ipv6_pktlen(struct rte_mbuf *m, const struct rte_ipv6_hdr *iph,
> +	uint32_t l2_len)
> +{
> +	uint32_t plen, trim;
> +
> +	plen = rte_be_to_cpu_16(iph->payload_len) + sizeof(*iph) + l2_len;
> +	if (plen < m->pkt_len) {
> +		trim = m->pkt_len - plen;
> +		rte_pktmbuf_trim(m, trim);
> +	}
> +}
> +
>  static inline void
>  prepare_one_packet(struct rte_mbuf *pkt, struct ipsec_traffic *t)
>  {
> -	uint8_t *nlp;
> -	struct rte_ether_hdr *eth;
> +	const struct rte_ether_hdr *eth;
> +	const struct rte_ipv4_hdr *iph4;
> +	const struct rte_ipv6_hdr *iph6;
> 
> -	eth = rte_pktmbuf_mtod(pkt, struct rte_ether_hdr *);
> +	eth = rte_pktmbuf_mtod(pkt, const struct rte_ether_hdr *);
>  	if (eth->ether_type == rte_cpu_to_be_16(RTE_ETHER_TYPE_IPV4)) {
> -		nlp = (uint8_t *)rte_pktmbuf_adj(pkt, RTE_ETHER_HDR_LEN);
> -		nlp = RTE_PTR_ADD(nlp, offsetof(struct ip, ip_p));
> -		if (*nlp == IPPROTO_ESP)
> +
> +		iph4 = (const struct rte_ipv4_hdr *)rte_pktmbuf_adj(pkt,
> +			RTE_ETHER_HDR_LEN);
> +		adjust_ipv4_pktlen(pkt, iph4, 0);
> +
> +		if (iph4->next_proto_id == IPPROTO_ESP)
>  			t->ipsec.pkts[(t->ipsec.num)++] = pkt;
>  		else {
> -			t->ip4.data[t->ip4.num] = nlp;
> +			t->ip4.data[t->ip4.num] = &iph4->next_proto_id;
>  			t->ip4.pkts[(t->ip4.num)++] = pkt;
>  		}
>  		pkt->l2_len = 0;
> -		pkt->l3_len = sizeof(struct ip);
> +		pkt->l3_len = sizeof(*iph4);
>  	} else if (eth->ether_type == rte_cpu_to_be_16(RTE_ETHER_TYPE_IPV6))
> {
> -		nlp = (uint8_t *)rte_pktmbuf_adj(pkt, RTE_ETHER_HDR_LEN);
> -		nlp = RTE_PTR_ADD(nlp, offsetof(struct ip6_hdr, ip6_nxt));
> -		if (*nlp == IPPROTO_ESP)
> +
> +		iph6 = (const struct rte_ipv6_hdr *)rte_pktmbuf_adj(pkt,
> +			RTE_ETHER_HDR_LEN);
> +		adjust_ipv6_pktlen(pkt, iph6, 0);
> +
> +		if (iph6->proto == IPPROTO_ESP)
>  			t->ipsec.pkts[(t->ipsec.num)++] = pkt;
>  		else {
> -			t->ip6.data[t->ip6.num] = nlp;
> +			t->ip6.data[t->ip6.num] = &iph6->proto;
>  			t->ip6.pkts[(t->ip6.num)++] = pkt;
>  		}
>  		pkt->l2_len = 0;
> -		pkt->l3_len = sizeof(struct ip6_hdr);
> +		pkt->l3_len = sizeof(*iph6);
>  	} else {
>  		/* Unknown/Unsupported type, drop the packet */
>  		RTE_LOG(ERR, IPSEC, "Unsupported packet type 0x%x\n",
> --
> 2.17.1
  

Hi Akhil, 

> 
> Hi Konstantin,
> 
> Could you please rebase this patchset. There are some conflicting changes because of Marcin's patches.
> Also could you please squash your doc patch with " examples/ipsec-secgw: support packet fragmentation and reassembly "
> As per convention followed, there should not be separate doc patches.

Sure, will do.
Konstantin