netdev - Re: BPF: ETLS: RECV FLOW

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Date:   Sun, 4 Aug 2019 15:09:02 +0530
From:   Shridhar Venkatraman <shridhar@...mtree.com>
To:     netdev@...r.kernel.org
Subject: Re: BPF: ETLS: RECV FLOW

Hi,

The eTLS work has BPF integration which is great.
However there is one spot where access to the clear text is not available.

>From kernel 4.20 - receiver BPF support added for KTLS.

a. receiver BPF is applied on encrypted message
b. after applying BPF, message is decrypted
c. BPF run logic on the decrypted plain message   - can we add this support ?
d. then copy the decrypted message back to userspace.

code flow reference: tls receive message call flow:
--------------------------------------------------------------

tls_sw_recvmsg
  __tcp_bpf_recvmsg [ bpf exec function called on encrypted message ]
  decrypt_skb_update
  decrypt_internal
  BPF_PROG_RUN on decrypted plain message - can we add this support ?
  skb_copy_datagram_msg [ decrypted message copied back to userspace ]

Thanks
ps: I sent this to the bpf list as I don't know which one it should go to