Re: [MPTCP] [PATCH v2 00/25] TCP Extra-option framework for TCP-MD5 and SMC

Finally, the second version of this patch-set. At netdev I talked about this with Eric, and he is looking forward to see TCP-MD5 get out of the hot TCP data-path. He was planning to avoid TCP-MD5 with static jump-labels and also move TCP-MD5 in a separate file.

There are quite a few changes in this new set. I extended much more the extra-option framework. Making the list on a per-socket basis in the request-socket, tcp-socket and time-wait-socket. This eliminates the need for RCU-locking. See patch "tcp_extra_options: Make extra-option list per-socket" I also added callbacks for response_write/prepare that can be called from the tcp_v4_send_ack/rst, and v6 counterparts. This is needed because in these code-paths the skb and sk have entirely different semantics. Finally, in the input-path I added a check-callback and a post-process callback. This is needed because after parsing the option in tcp_parse_options() we also need to act on them. The actions can be either before any other checks (e.g., as is the case for TCP_MD5, because we want to drop segments) or after the validity checks (e.g., as is needed for SMC). And I also opted SMC into the new framework. And, I made the TCP-MD5 input code-path use the framework.

There are still a few things that I need to double-check, notably sk_nocaps_add() in TCP_MD5. And, I need to test ;-)

But I would like to have some early feedback already - especially on the patches prefixed with "tcp_extra_options". If they look good, I can merge them into Mat's patch, which will simplify my patch-juggling.

I want to get this patch-set out to netdev as an RFC as quickly as possible, so that we can make some progress.

Christoph Paasch (24): tcp: Write options after the header has been fully done tcp: Pass sock to tcp_options_write instead of tcp_sock tcp: Pass skb in tcp_options_write tcp: Allow tcp_fast_parse_options to drop segments tcp: Make smc_parse_options return 1 on success tcp_md5: Don't pass along md5-key tcp_md5: Detect key inside tcp_v4_send_ack instead of passing it as an argument tcp_md5: Detect key inside tcp_v6_send_response instead of passing it as an argument tcp_extra_options: Extend tcp_extra_options_write tcp_extra_options: Make extra-option list per-socket tcp_extra_options: Export module fixes tcp_extra_options: Add response_prepare callback tcp_extra_options: Check static branch before _parse tcp_extra_options: Skip fast-path when extra-options are present tcp_extra_options: Pass sk to tcp_parse_options instead of tp tcp_extra_options: Add check-callback right after parsing the option tcp_extra_options: Allow to parse experimental options tcp_extra_options: Add post_process callback tcp_smc: Make SMC use TCP extra-option framework tcp_md5: Check for TCP_MD5 after TCP Timestamps in tcp_established_options tcp_md5: Move TCP-MD5 code out of TCP itself tcp_md5: Use tcp_extra_options in output path tcp_md5: Cleanup TCP-code tcp_md5: Use TCP extra-options on the input path Mat Martineau (1): tcp: Register handlers for extra TCP options drivers/infiniband/hw/cxgb4/cm.c | 2 +- include/linux/inet_diag.h | 1 + include/linux/tcp.h | 41 +- include/linux/tcp_md5.h | 38 ++ include/net/inet_sock.h | 3 +- include/net/tcp.h | 216 ++++--- net/ipv4/Makefile | 1 + net/ipv4/syncookies.c | 6 +- net/ipv4/tcp.c | 372 ++++++++--- net/ipv4/tcp_diag.c | 81 +-- net/ipv4/tcp_input.c | 134 ++-- net/ipv4/tcp_ipv4.c | 553 ++-------------- net/ipv4/tcp_md5.c | 1317 ++++++++++++++++++++++++++++++++++++++ net/ipv4/tcp_minisocks.c | 76 +-- net/ipv4/tcp_output.c | 183 +----- net/ipv6/syncookies.c | 6 +- net/ipv6/tcp_ipv6.c | 386 ++--------- net/smc/af_smc.c | 170 ++++- 18 files changed, 2148 insertions(+), 1438 deletions(-) create mode 100644 include/linux/tcp_md5.h create mode 100644 net/ipv4/tcp_md5.c -- 2.15.0