On 2/18/20 6:10 PM, Jakub Sitnicki wrote:
This patch set turns SOCK{MAP,HASH} into generic collections for TCP
sockets, both listening and established. Adding support for listening
sockets enables us to use these BPF map types with reuseport BPF programs.
Why? SOCKMAP and SOCKHASH, in comparison to REUSEPORT_SOCKARRAY, allow the
socket to be in more than one map at the same time.
Having a BPF map type that can hold listening sockets, and gracefully
co-exist with reuseport BPF is important if, in the future, we want
BPF programs that run at socket lookup time [0]. Cover letter for v1 of
this series tells the full story of how we got here [1].
Although SOCK{MAP,HASH} are not a drop-in replacement for SOCKARRAY just
yet, because UDP support is lacking, it's a step in this direction. We're
working with Lorenz on extending SOCK{MAP,HASH} to hold UDP sockets, and
expect to post RFC series for sockmap + UDP in the near future.
I've dropped Acks from all patches that have been touched since v6.
The audit for missing READ_ONCE annotations for access to sk_prot is
ongoing. Thus far I've found one location specific to TCP listening sockets
that needed annotating. This got fixed it in this iteration. I wonder if
sparse checker could be put to work to identify places where we have
sk_prot access while not holding sk_lock...
The patch series depends on another one, posted earlier [2], that has been
split out of it.
Thanks,
jkbs
[0] https://lore.kernel.org/bpf/20190828072250.29828-1-jakub@xxxxxxxxxxxxxx/
[1] https://lore.kernel.org/bpf/20191123110751.6729-1-jakub@xxxxxxxxxxxxxx/
[2] https://lore.kernel.org/bpf/20200217121530.754315-1-jakub@xxxxxxxxxxxxxx/
v6 -> v7:
- Extended the series to cover SOCKHASH. (patches 4-8, 10-11) (John)
- Rebased onto recent bpf-next. Resolved conflicts in recent fixes to
sk_state checks on sockmap/sockhash update path. (patch 4)
- Added missing READ_ONCE annotation in sock_copy. (patch 1)
- Split out patches that simplify sk_psock_restore_proto [2].
Applied, thanks!
