BPF: ETLS: RECV FLOW

BPF: ETLS: RECV FLOW

[Shridhar Venkatraman]

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