On Fri, Jan 17, 2020 at 07:08:05PM +0530, Ayush Sawal wrote: > Hi steffen, > > On 1/17/2020 5:47 PM, Steffen Klassert wrote: > > On Fri, Jan 17, 2020 at 04:28:54PM +0530, Ayush Sawal wrote: > > > Hi steffen, > > > > > > On 1/17/2020 12:34 PM, Steffen Klassert wrote: > > > > On Fri, Jan 17, 2020 at 12:13:07PM +0530, Ayush Sawal wrote: > > > > > Hi Herbert, > > > > > > > > > > On 1/17/2020 11:53 AM, Herbert Xu wrote: > > > > > > On Thu, Jan 16, 2020 at 01:27:24PM +0530, Ayush Sawal wrote: > > > > > > > The max data limit is 15 sgs where each sg contains data of mtu size . > > > > > > > we are running a netperf udp stream test over ipsec tunnel .The ipsec tunnel > > > > > > > is established between two hosts which are directly connected > > > > > > Are you actually getting 15-element SG lists from IPsec? What is > > > > > > generating an skb with 15-element SG lists? > > > > > we have established the ipsec tunnel in transport mode using ip xfrm. > > > > > and running traffic using netserver and netperf. > > > > > > > > > > In server side we are running > > > > > netserver -4 > > > > > In client side we are running > > > > > "netperf -H <serverip> -p <port> -t UDP_STREAM -Cc -- -m 21k" > > > > > where the packet size is 21k ,which is then fragmented into 15 ip fragments > > > > > each of mtu size. > > > > I'm lacking a bit of context here, but this should generate 15 IP > > > > packets that are encrypted one by one. > > > This is what i observed ,please correct me if i am wrong. > > > The packet when reaches esp_output(),is in socket buffer and based on the > > > number of frags ,sg is initialized using > > > sg_init_table(sg,frags),where frags are 15 in our case. > > The packet should be IP fragmented before it enters esp_output() > > unless this is a UDP GSO packet. What kind of device do you use > > here? Is it a crypto accelerator or a NIC that can do ESP offloads? > > We have device which works as a crypto accelerator . It just encrypts the > packets and send it back to kernel. I just did a test and I see the same behaviour. Seems like I was mistaken, we actually fragment the ESP packets. The only case where we do pre-encap fragmentation is IPv6 tunnel mode. But I wonder if it would make sense to avoid to have ESP fragments on the wire.
