[PATCH ipsec-next v2 0/6] ipsec: add TCP encapsulation support (RFC 8229)

[Sabrina Dubroca <sd@queasysnail.net>]

This patchset introduces support for TCP encapsulation of IKE and ESP
messages, as defined by RFC 8229 [0]. It is an evolution of what
Herbert Xu proposed in January 2018 [1] that addresses the main
criticism against it, by not interfering with the TCP implementation
at all. The networking stack now has infrastructure for this: TCP ULPs
and Stream Parsers.

The first patches are preparation and refactoring, and the final patch
adds the feature.

The main omission in this submission is IPv6 support. ESP
encapsulation over UDP with IPv6 is currently not supported in the
kernel either, as UDP encapsulation is aimed at NAT traversal, and NAT
is not frequently used with IPv6.

Some of the code is taken directly, or slightly modified, from Herbert
Xu's original submission [1]. The ULP and strparser pieces are
new. This work was presented and discussed at the IPsec workshop and
netdev 0x13 conference [2] in Prague, last March.

[0] https://tools.ietf.org/html/rfc8229
[1] https://patchwork.ozlabs.org/patch/859107/
[2] https://netdevconf.org/0x13/session.html?talk-ipsec-encap

Changes since v1:
 - drop patch 1, already present in the tree as commit bd95e678e0f6
   ("bpf: sockmap, fix use after free from sleep in psock backlog
   workqueue")
 - patch 1/6: fix doc error reported by kbuild test robot <lkp@intel.com>
 - patch 6/6, fix things reported by Steffen Klassert:
   - remove unneeded goto and improve error handling in
     esp_output_tcp_finish
   - clean up the ifdefs by providing dummy implementations of those
     functions
   - fix Kconfig select, missing NET_SOCK_MSG

Sabrina Dubroca (6):
  net: add queue argument to __skb_wait_for_more_packets and
    __skb_{,try_}recv_datagram
  xfrm: introduce xfrm_trans_queue_net
  xfrm: add route lookup to xfrm4_rcv_encap
  esp4: prepare esp_input_done2 for non-UDP encapsulation
  esp4: split esp_output_udp_encap and introduce esp_output_encap
  xfrm: add espintcp (RFC 8229)

 include/linux/skbuff.h    |  11 +-
 include/net/espintcp.h    |  38 +++
 include/net/xfrm.h        |   4 +
 include/uapi/linux/udp.h  |   1 +
 net/core/datagram.c       |  27 +-
 net/ipv4/esp4.c           | 264 ++++++++++++++++++--
 net/ipv4/udp.c            |   3 +-
 net/ipv4/xfrm4_protocol.c |   9 +
 net/unix/af_unix.c        |   7 +-
 net/xfrm/Kconfig          |  10 +
 net/xfrm/Makefile         |   1 +
 net/xfrm/espintcp.c       | 505 ++++++++++++++++++++++++++++++++++++++
 net/xfrm/xfrm_input.c     |  21 +-
 net/xfrm/xfrm_policy.c    |   7 +
 net/xfrm/xfrm_state.c     |   3 +
 15 files changed, 865 insertions(+), 46 deletions(-)
 create mode 100644 include/net/espintcp.h
 create mode 100644 net/xfrm/espintcp.c

-- 
2.22.0