TCP socket iterators use iter->offset to track progress through a
bucket, which is a measure of the number of matching sockets from the
current bucket that have been seen or processed by the iterator. On
subsequent iterations, if the current bucket has unprocessed items, we
skip at least iter->offset matching items in the bucket before adding
any remaining items to the next batch. However, iter->offset isn't
always an accurate measure of "things already seen" when the underlying
bucket changes between reads which can lead to repeated or skipped
sockets. Instead, this series remembers the cookies of the sockets we
haven't seen yet in the current bucket and resumes from the first cookie
in that list that we can find on the next iteration.
This is a continuation of the work started in [1]. This series largely
replicates the patterns applied to UDP socket iterators, applying them
instead to TCP socket iterators.
Note: This series depends on [1] to apply cleanly, which is currently
available only in bpf-next/net. As such, CI may not pass if it
tries to test on top of bpf-next/master, but manual CI executions
on my branch that included commits from [1] were green.
[1]: https://lore.kernel.org/bpf/20250502161528.264630-1-jordan@xxxxxxxx/
Jordan Rife (10):
bpf: tcp: Make mem flags configurable through
bpf_iter_tcp_realloc_batch
bpf: tcp: Make sure iter->batch always contains a full bucket snapshot
bpf: tcp: Get rid of st_bucket_done
bpf: tcp: Use bpf_tcp_iter_batch_item for bpf_tcp_iter_state batch
items
bpf: tcp: Avoid socket skips and repeats during iteration
selftests/bpf: Add tests for bucket resume logic in listening sockets
selftests/bpf: Allow for iteration over multiple ports
selftests/bpf: Make ehash buckets configurable in socket iterator
tests
selftests/bpf: Create established sockets in socket iterator tests
selftests/bpf: Add tests for bucket resume logic in established
sockets
net/ipv4/tcp_ipv4.c | 262 ++++++++---
.../bpf/prog_tests/sock_iter_batch.c | 442 +++++++++++++++++-
.../selftests/bpf/progs/sock_iter_batch.c | 4 +
3 files changed, 631 insertions(+), 77 deletions(-)
--
2.43.0
