Re: [PATCH v2 1/2] udp: UDP socket send queue repair

From: Eric Dumazet
Date: Wed Aug 11 2021 - 12:14:41 EST




On 8/11/21 5:45 PM, Bui Quang Minh wrote:
> In this patch, I implement UDP_REPAIR sockoption and a new path in
> udp_recvmsg for dumping the corked packet in UDP socket's send queue.
>
> A userspace program can use recvmsg syscall to get the packet's data and
> the msg_name information of the packet. Currently, other related
> information in inet_cork that are set in cmsg are not dumped.
>
> While working on this, I was aware of Lese Doru Calin's patch and got some
> ideas from it.


What is the use case for this feature, adding a test in UDP fast path ?

CORKed UDP is hardly used nowadays.

IMO, TCP_REPAIR hijacking standard system calls was a design error,
we should have added new system calls.