Packet->append does increase the data region, but the packet len value stays the same.

[sarsanaee]

Once we allocate a packet, we usually append some free space to be able to fit our data in the packet.

The way we are doing this is by calling packet->alloc. This, however, does not change the packet length property.

So if we call packet->length() we do not observe the new length there. Check here as an example:

machnet/src/include/machnet_engine.h

Line 928 in 15a937d

auto *response = CHECK_NOTNULL(packet_pool_->PacketAlloc());

[marinosi]

Hi Ryan Sana (@sarsanaee),

Could you please elaborate on the issue?

PacketAlloc() is not meant to change the underlying mbuf size; it's merely an allocation from the pool.

The append method, is increasing the length of the packet using the underlying DPDK function.

machnet/src/include/packet.h

Line 132 in 15a937d

template <typename T = void *>

Does this not work? Or you are pointing out that in this line:

machnet/src/include/machnet_engine.h

Line 929 in 15a937d

auto *response_eh = response->append<Ethernet *>(pkt->length());

there is no check for the return value ?