| Message ID | 20221027204347.529913-1-dima@arista.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | net/tcp: Add TCP-AO support | expand |
Thinking about how to move the TCP-AO intent forward: clearly a 36-patch set is a bit much. The first 6 patches are prep work, and we know there is a use case for those. We could handle patches 3 and 4 as a stand alone set first. Once merged, deal with the crypto API and users until those maintainers are good. That would be patches 1, 2, 5 and 6. Once those are merged it drops down to just networking patches with selftests. Those can be split into AO (19) and selftests (11) making it 4 total sets of manageable size. The AO patches can be reviewed until convergence on a good starting point. Sound reasonable?
Hi David, On 11/1/22 02:22, David Ahern wrote: > Thinking about how to move the TCP-AO intent forward: clearly a 36-patch > set is a bit much. The first 6 patches are prep work, and we know there > is a use case for those. > > We could handle patches 3 and 4 as a stand alone set first. > > Once merged, deal with the crypto API and users until those maintainers > are good. That would be patches 1, 2, 5 and 6. > > Once those are merged it drops down to just networking patches with > selftests. Those can be split into AO (19) and selftests (11) making it > 4 total sets of manageable size. > > The AO patches can be reviewed until convergence on a good starting point. > > Sound reasonable? That sounds reasonable to me. I'll submit patches 3 & 4 for review and then, once merged, 1, 2, 5 and 6. And later (re)-base TCP-AO on linux-next. Thanks, Dmitry
In TODO (expect in next versions): - Documentation/ page about TCP-AO kernel design, UAPI - Support VRFs in setsockopt() - setsockopt() UAPI padding + a test that structures are of the same size on 32-bit as on 64-bit platforms - IPv4-mapped-IPv6 addresses - Measure/benchmark TCP-AO and regular TCP connections (on hw) - setsockopt(TCP_REPAIR) with TCP-AO Changes from v2: - Added more missing `static' declarations for local functions (kernel test robot <lkp@intel.com>) - Building now with CONFIG_TCP_AO=n and CONFIG_TCP_MD5SIG=n (kernel test robot <lkp@intel.com>) - Now setsockopt(TCP_AO) is allowed when it's TCP_LISTEN or TCP_CLOSE state OR the key added is not the first key on a socket (by Salam) - CONFIG_TCP_AO does not depend on CONFIG_TCP_MD5SIG anymore - Don't leak tcp_md5_needed static branch counter when TCP-MD5 key is modified/changed - TCP-AO lookups are dynamically enabled/disabled with static key when there is ao_info in the system (and when it is destroyed) - Wired SYN cookies up to TCP-AO (by Salam) - Fix verification for possible re-transmitted SYN packets (by Salam) - use sockopt_lock_sock() instead of lock_sock() (from v6.1 rebase, commit d51bbff2aba7) - use sockptr_t in getsockopt(TCP_AO_GET) (from v6.1 rebase, commit 34704ef024ae) - Fixed reallocating crypto_pool's scratch area by IPI while crypto_pool_get() was get by another CPU - selftests on older kernels (or with CONFIG_TCP_AO=n) should exit with SKIP, not FAIL (Shuah Khan <shuah@kernel.org>) - selftests that check interaction between TCP-AO and TCP-MD5 now SKIP when CONFIG_TCP_MD5SIG=n - Measured the performance of different hashing algorithms for TCP-AO and compare with TCP-MD5 performance. This is done with hacky patches to iperf (see [3]). At this moment I've done it in qemu/KVM with CPU affinities set on Intel(R) Core(TM) i7-7600U CPU @ 2.80GHz. No performance degradation was noticed before/after patches, but given the measures were done in a VM, without measuring it on a physical dut it only gives a hint of relative speed for different hash algorithms with TCP-AO. Here are results, averaging on 30 measures each: TCP: 3.51Gbits/sec TCP-MD5: 1.12Gbits/sec TCP-AO(HMAC(SHA1)): 1.53Gbits/sec TCP-AO(CMAC(AES128)): 621Mbits/sec TCP-AO(HMAC(SHA512)): 1.21Gbits/sec TCP-AO(HMAC(SHA384)): 1.20Gbits/sec TCP-AO(HMAC(SHA224)): 961Mbits/sec TCP-AO(HMAC(SHA3-512)): 157Mbits/sec TCP-AO(HMAC(RMD160)): 659Mbits/sec TCP-AO(HMAC(MD5): 1.12Gbits/sec (the last one is just for fun, but may make sense as it provides the same security as TCP-MD5, but allows multiple keys and a mechanism to change them from RFC5925) Changes from v1: - Building now with CONFIG_IPV6=n (kernel test robot <lkp@intel.com>) - Added missing static declarations for local functions (kernel test robot <lkp@intel.com>) - Addressed static analyzer and review comments by Dan Carpenter (thanks, they were very useful!) - Fix elif without defined() for !CONFIG_TCP_AO - Recursively build selftests/net/tcp_ao (Shuah Khan), patches in: https://lore.kernel.org/all/20220919201958.279545-1-dima@arista.com/T/#u - Don't leak crypto_pool reference when TCP-MD5 key is modified/changed - Add TCP-AO support for nettest.c and fcnal-test.sh (will be used for VRF testing in later versions) Comparison between Leonard proposal and this (overview): https://lore.kernel.org/all/3cf03d51-74db-675c-b392-e4647fa5b5a6@arista.com/T/#u Version 2: https://lore.kernel.org/all/20220923201319.493208-1-dima@arista.com/T/#u Version 1: https://lore.kernel.org/all/20220818170005.747015-1-dima@arista.com/T/#u This patchset implements the TCP-AO option as described in RFC5925. There is a request from industry to move away from TCP-MD5SIG and it seems the time is right to have a TCP-AO upstreamed. This TCP option is meant to replace the TCP MD5 option and address its shortcomings. Specifically, it provides more secure hashing, key rotation and support for long-lived connections (see the summary of TCP-AO advantages over TCP-MD5 in (1.3) of RFC5925). The patch series starts with six patches that are not specific to TCP-AO but implement a general crypto facility that we thought is useful to eliminate code duplication between TCP-MD5SIG and TCP-AO as well as other crypto users. These six patches are being submitted separately in a different patchset [1]. Including them here will show better the gain in code sharing. Next are 18 patches that implement the actual TCP-AO option, followed by patches implementing selftests. The patch set was written as a collaboration of three authors (in alphabetical order): Dmitry Safonov, Francesco Ruggeri and Salam Noureddine. Additional credits should be given to Prasad Koya, who was involved in early prototyping a few years back. There is also a separate submission done by Leonard Crestez whom we thank for his efforts getting an implementation of RFC5925 submitted for review upstream [2]. This is an independent implementation that makes different design decisions. For example, we chose a similar design to the TCP-MD5SIG implementation and used setsockopts to program per-socket keys, avoiding the extra complexity of managing a centralized key database in the kernel. A centralized database in the kernel has dubious benefits since it doesn’t eliminate per-socket setsockopts needed to specify which sockets need TCP-AO and what are the currently preferred keys. It also complicates traffic key caching and preventing deletion of in-use keys. In this implementation, a centralized database of keys can be thought of as living in user space and user applications would have to program those keys on matching sockets. On the server side, the user application programs keys (MKTS in TCP-AO nomenclature) on the listening socket for all peers that are expected to connect. Prefix matching on the peer address is supported. When a peer issues a successful connect, all the MKTs matching the IP address of the peer are copied to the newly created socket. On the active side, when a connect() is issued all MKTs that do not match the peer are deleted from the socket since they will never match the peer. This implementation uses three setsockopt()s for adding, deleting and modifying keys on a socket. All three setsockopt()s have extensive sanity checks that prevent inconsistencies in the keys on a given socket. A getsockopt() is provided to get key information from any given socket. Few things to note about this implementation: - Traffic keys are cached for established connections avoiding the cost of such calculation for each packet received or sent. - Great care has been taken to avoid deleting in-use MKTs as required by the RFC. - Any crypto algorithm supported by the Linux kernel can be used to calculate packet hashes. - Fastopen works with TCP-AO but hasn’t been tested extensively. - Tested for interop with other major networking vendors (on linux-4.19), including testing for key rotation and long lived connections. [1]: https://lore.kernel.org/all/20220726201600.1715505-1-dima@arista.com/ [2]: https://lore.kernel.org/all/cover.1658815925.git.cdleonard@gmail.com/ [3]: https://github.com/0x7f454c46/iperf/tree/tcp-md5-ao Cc: Andy Lutomirski <luto@amacapital.net> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Bob Gilligan <gilligan@arista.com> Cc: Dan Carpenter <dan.carpenter@oracle.com> Cc: David Ahern <dsahern@kernel.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Dmitry Safonov <0x7f454c46@gmail.com> Cc: Eric Biggers <ebiggers@kernel.org> Cc: Eric Dumazet <edumazet@google.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Francesco Ruggeri <fruggeri@arista.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org> Cc: Ivan Delalande <colona@arista.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Leonard Crestez <cdleonard@gmail.com> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Salam Noureddine <noureddine@arista.com> Cc: Shuah Khan <shuah@kernel.org> Cc: netdev@vger.kernel.org Cc: linux-crypto@vger.kernel.org Cc: linux-kernel@vger.kernel.org Dmitry Safonov (36): crypto: Introduce crypto_pool crypto_pool: Add crypto_pool_reserve_scratch() net/tcp: Separate tcp_md5sig_info allocation into tcp_md5sig_info_add() net/tcp: Disable TCP-MD5 static key on tcp_md5sig_info destruction net/tcp: Use crypto_pool for TCP-MD5 net/ipv6: sr: Switch to using crypto_pool tcp: Add TCP-AO config and structures net/tcp: Introduce TCP_AO setsockopt()s net/tcp: Prevent TCP-MD5 with TCP-AO being set net/tcp: Calculate TCP-AO traffic keys net/tcp: Add TCP-AO sign to outgoing packets net/tcp: Add tcp_parse_auth_options() net/tcp: Add AO sign to RST packets net/tcp: Add TCP-AO sign to twsk net/tcp: Wire TCP-AO to request sockets net/tcp: Sign SYN-ACK segments with TCP-AO net/tcp: Verify inbound TCP-AO signed segments net/tcp: Add TCP-AO segments counters net/tcp: Add TCP-AO SNE support net/tcp: Add tcp_hash_fail() ratelimited logs net/tcp: Ignore specific ICMPs for TCP-AO connections net/tcp: Add option for TCP-AO to (not) hash header net/tcp: Add getsockopt(TCP_AO_GET) net/tcp: Allow asynchronous delete for TCP-AO keys (MKTs) net/tcp-ao: Add static_key for TCP-AO selftests/net: Add TCP-AO library selftests/net: Verify that TCP-AO complies with ignoring ICMPs selftest/net: Add TCP-AO ICMPs accept test selftest/tcp-ao: Add a test for MKT matching selftest/tcp-ao: Add test for TCP-AO add setsockopt() command selftests/tcp-ao: Add TCP-AO + TCP-MD5 + no sign listen socket tests selftests/aolib: Add test/benchmark for removing MKTs selftests/nettest: Remove client_pw selftest/nettest: Rename md5_prefix* => auth_prefix* selftests/nettest: Add TCP-AO support selftests/fcnal-test.sh: Add TCP-AO tests crypto/Kconfig | 12 + crypto/Makefile | 1 + crypto/crypto_pool.c | 338 +++ include/crypto/pool.h | 33 + include/linux/sockptr.h | 23 + include/linux/tcp.h | 30 +- include/net/dropreason.h | 25 + include/net/seg6_hmac.h | 7 - include/net/tcp.h | 195 +- include/net/tcp_ao.h | 305 +++ include/uapi/linux/snmp.h | 5 + include/uapi/linux/tcp.h | 62 + net/ipv4/Kconfig | 14 +- net/ipv4/Makefile | 1 + net/ipv4/proc.c | 5 + net/ipv4/syncookies.c | 2 + net/ipv4/tcp.c | 197 +- net/ipv4/tcp_ao.c | 2038 +++++++++++++++++ net/ipv4/tcp_input.c | 105 +- net/ipv4/tcp_ipv4.c | 404 +++- net/ipv4/tcp_minisocks.c | 37 +- net/ipv4/tcp_output.c | 192 +- net/ipv6/Kconfig | 2 +- net/ipv6/Makefile | 1 + net/ipv6/seg6.c | 3 - net/ipv6/seg6_hmac.c | 204 +- net/ipv6/syncookies.c | 2 + net/ipv6/tcp_ao.c | 151 ++ net/ipv6/tcp_ipv6.c | 357 ++- tools/testing/selftests/Makefile | 1 + tools/testing/selftests/net/fcnal-test.sh | 471 +++- tools/testing/selftests/net/nettest.c | 217 +- tools/testing/selftests/net/tcp_ao/.gitignore | 2 + tools/testing/selftests/net/tcp_ao/Makefile | 50 + .../selftests/net/tcp_ao/bench-lookups.c | 403 ++++ .../selftests/net/tcp_ao/connect-deny.c | 217 ++ tools/testing/selftests/net/tcp_ao/connect.c | 81 + .../selftests/net/tcp_ao/icmps-accept.c | 1 + .../selftests/net/tcp_ao/icmps-discard.c | 446 ++++ .../testing/selftests/net/tcp_ao/lib/aolib.h | 336 +++ .../selftests/net/tcp_ao/lib/netlink.c | 341 +++ tools/testing/selftests/net/tcp_ao/lib/proc.c | 267 +++ .../testing/selftests/net/tcp_ao/lib/setup.c | 343 +++ tools/testing/selftests/net/tcp_ao/lib/sock.c | 294 +++ .../testing/selftests/net/tcp_ao/lib/utils.c | 30 + .../selftests/net/tcp_ao/setsockopt-closed.c | 191 ++ .../selftests/net/tcp_ao/unsigned-md5.c | 524 +++++ 47 files changed, 8323 insertions(+), 643 deletions(-) create mode 100644 crypto/crypto_pool.c create mode 100644 include/crypto/pool.h create mode 100644 include/net/tcp_ao.h create mode 100644 net/ipv4/tcp_ao.c create mode 100644 net/ipv6/tcp_ao.c create mode 100644 tools/testing/selftests/net/tcp_ao/.gitignore create mode 100644 tools/testing/selftests/net/tcp_ao/Makefile create mode 100644 tools/testing/selftests/net/tcp_ao/bench-lookups.c create mode 100644 tools/testing/selftests/net/tcp_ao/connect-deny.c create mode 100644 tools/testing/selftests/net/tcp_ao/connect.c create mode 120000 tools/testing/selftests/net/tcp_ao/icmps-accept.c create mode 100644 tools/testing/selftests/net/tcp_ao/icmps-discard.c create mode 100644 tools/testing/selftests/net/tcp_ao/lib/aolib.h create mode 100644 tools/testing/selftests/net/tcp_ao/lib/netlink.c create mode 100644 tools/testing/selftests/net/tcp_ao/lib/proc.c create mode 100644 tools/testing/selftests/net/tcp_ao/lib/setup.c create mode 100644 tools/testing/selftests/net/tcp_ao/lib/sock.c create mode 100644 tools/testing/selftests/net/tcp_ao/lib/utils.c create mode 100644 tools/testing/selftests/net/tcp_ao/setsockopt-closed.c create mode 100644 tools/testing/selftests/net/tcp_ao/unsigned-md5.c base-commit: 4dc12f37a8e98e1dca5521c14625c869537b50b6