On 6/25/2020 1:27 PM, Andrew Rybchenko wrote:
> On 5/29/20 8:43 AM, Stephen Hemminger wrote:
>> On Wed, 27 May 2020 15:31:41 +0100
>> Andrew Rybchenko <arybche...@solarflare.com> wrote:
>>
>>> SW VLAN insertion relies on Ethernet addresses location in contigous
>>> memory (do not split across mbuf segments). There is no any formal
>>> requirements on data location and mbuf structure which guarantee it.
>>> So, check it explicitly to avoid corrupted packets if the condition
>>> is violated. Typically software VLAN insertion is done on Tx prepare
>>> stage and application will get indication that the packet is invalid
>>> and cannot be transmitted.
>>>
>>> Signed-off-by: Andrew Rybchenko <arybche...@solarflare.com>
>>> ---
>>> lib/librte_net/rte_ether.h | 4 ++++
>>> 1 file changed, 4 insertions(+)
>>>
>>> diff --git a/lib/librte_net/rte_ether.h b/lib/librte_net/rte_ether.h
>>> index 0ae4e75b6c..d7c076bba8 100644
>>> --- a/lib/librte_net/rte_ether.h
>>> +++ b/lib/librte_net/rte_ether.h
>>> @@ -357,6 +357,10 @@ static inline int rte_vlan_insert(struct rte_mbuf **m)
>>> if (!RTE_MBUF_DIRECT(*m) || rte_mbuf_refcnt_read(*m) > 1)
>>> return -EINVAL;
>>>
>>> + /* Can't insert header if the first segment is too short */
>>> + if (rte_pktmbuf_data_len(*m) < 2 * RTE_ETHER_ADDR_LEN)
>>> + return -EINVAL;
>>
>> Looks good, but you could also make it handle the fragment case with:
>>
>> diff --git a/lib/librte_net/rte_ether.h b/lib/librte_net/rte_ether.h
>> index 0ae4e75b6c58..4d0e310a4fac 100644
>> --- a/lib/librte_net/rte_ether.h
>> +++ b/lib/librte_net/rte_ether.h
>> @@ -350,14 +350,18 @@ static inline int rte_vlan_strip(struct rte_mbuf *m)
>> */
>> static inline int rte_vlan_insert(struct rte_mbuf **m)
>> {
>> - struct rte_ether_hdr *oh, *nh;
>> + struct rte_ether_hdr *nh, tmp;
>> + const struct rte_ether_hdr *oh;
>> 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;
>>
>> - oh = rte_pktmbuf_mtod(*m, struct rte_ether_hdr *);
>> + oh = rte_pktmbuf_read(*m, 0, sizeof(*oh), &tmp);
>> + if (unlikely(oh == NULL))
>> + return -EINVAL;
>> +
>> nh = (struct rte_ether_hdr *)
>> rte_pktmbuf_prepend(*m, sizeof(struct rte_vlan_hdr));
>> if (nh == NULL)
>>
>
> It is more complicated since memmove() below should be
> rewritten in a similar way as rte_pktmbuf_read(), but
> write. I'm not sure it worse the effort.
>
Reviewed-by: Ferruh Yigit <ferruh.yi...@intel.com>
Applied to dpdk-next-net/main, thanks.
