On Thu, Jul 22, 2021 at 03:25:39PM +0200, Eric Dumazet wrote: > > > On 7/1/21 10:05 PM, Martin KaFai Lau wrote: > > This set is to allow bpf tcp iter to call bpf_(get|set)sockopt. > > > > With bpf-tcp-cc, new algo rollout happens more often. Instead of > > restarting the applications to pick up the new tcp-cc, this set > > allows the bpf tcp iter to call bpf_(get|set)sockopt(TCP_CONGESTION). > > It is not limited to TCP_CONGESTION, the bpf tcp iter can call > > bpf_(get|set)sockopt() with other options. The bpf tcp iter can read > > into all the fields of a tcp_sock, so there is a lot of flexibility > > to select the desired sk to do setsockopt(), e.g. it can test for > > TCP_LISTEN only and leave the established connections untouched, > > or check the addr/port, or check the current tcp-cc name, ...etc. > > > > Patch 1-4 are some cleanup and prep work in the tcp and bpf seq_file. > > > > Patch 5 is to have the tcp seq_file iterate on the > > port+addr lhash2 instead of the port only listening_hash. > > > > Patch 6 is to have the bpf tcp iter doing batching which > > then allows lock_sock. lock_sock is needed for setsockopt. > > > > Patch 7 allows the bpf tcp iter to call bpf_(get|set)sockopt. > > > > v2: > > - Use __GFP_NOWARN in patch 6 > > - Add bpf_getsockopt() in patch 7 to give a symmetrical user experience. > > selftest in patch 8 is changed to also cover bpf_getsockopt(). > > - Remove CAP_NET_ADMIN check in patch 7. Tracing bpf prog has already > > required CAP_SYS_ADMIN or CAP_PERFMON. > > - Move some def macros to bpf_tracing_net.h in patch 8 > > > > Martin KaFai Lau (8): > > tcp: seq_file: Avoid skipping sk during tcp_seek_last_pos > > tcp: seq_file: Refactor net and family matching > > bpf: tcp: seq_file: Remove bpf_seq_afinfo from tcp_iter_state > > tcp: seq_file: Add listening_get_first() > > tcp: seq_file: Replace listening_hash with lhash2 > > bpf: tcp: bpf iter batching and lock_sock > > bpf: tcp: Support bpf_(get|set)sockopt in bpf tcp iter > > bpf: selftest: Test batching and bpf_(get|set)sockopt in bpf tcp iter > > For the whole series : > > Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx> > > Sorry for the delay. > > BTW, it seems weird for new BPF features to use /proc/net "legacy" > infrastructure and update it. bpf iter uses seq_file, so the initial bpf_iter_tcp reuses most of the pieces from /proc/net/tcp. This set refactored a few things such that the bpf_iter_tcp only shares the legacy tcp_seek_last_pos(), so the dependency on /proc/net/tcp should be less going forward. A similar modification could also be done to bpf_iter_udp in the future. Thanks for the review!
