diff options
author | Dmitry Safonov <dima@arista.com> | 2023-10-23 22:21:53 +0300 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2023-10-27 12:35:44 +0300 |
commit | 8c73b26315aadb82218360d0a9a05e515f6e4118 (patch) | |
tree | 75f950cf423f5488d419134a958663ef2caac17a /net/ipv4/tcp_minisocks.c | |
parent | cc54d2e2c58a40a82dfd39afa95d3d27f3d6509d (diff) | |
download | linux-8c73b26315aadb82218360d0a9a05e515f6e4118.tar.xz |
net/tcp: Prepare tcp_md5sig_pool for TCP-AO
TCP-AO, similarly to TCP-MD5, needs to allocate tfms on a slow-path,
which is setsockopt() and use crypto ahash requests on fast paths,
which are RX/TX softirqs. Also, it needs a temporary/scratch buffer
for preparing the hash.
Rework tcp_md5sig_pool in order to support other hashing algorithms
than MD5. It will make it possible to share pre-allocated crypto_ahash
descriptors and scratch area between all TCP hash users.
Internally tcp_sigpool calls crypto_clone_ahash() API over pre-allocated
crypto ahash tfm. Kudos to Herbert, who provided this new crypto API.
I was a little concerned over GFP_ATOMIC allocations of ahash and
crypto_request in RX/TX (see tcp_sigpool_start()), so I benchmarked both
"backends" with different algorithms, using patched version of iperf3[2].
On my laptop with i7-7600U @ 2.80GHz:
clone-tfm per-CPU-requests
TCP-MD5 2.25 Gbits/sec 2.30 Gbits/sec
TCP-AO(hmac(sha1)) 2.53 Gbits/sec 2.54 Gbits/sec
TCP-AO(hmac(sha512)) 1.67 Gbits/sec 1.64 Gbits/sec
TCP-AO(hmac(sha384)) 1.77 Gbits/sec 1.80 Gbits/sec
TCP-AO(hmac(sha224)) 1.29 Gbits/sec 1.30 Gbits/sec
TCP-AO(hmac(sha3-512)) 481 Mbits/sec 480 Mbits/sec
TCP-AO(hmac(md5)) 2.07 Gbits/sec 2.12 Gbits/sec
TCP-AO(hmac(rmd160)) 1.01 Gbits/sec 995 Mbits/sec
TCP-AO(cmac(aes128)) [not supporetd yet] 2.11 Gbits/sec
So, it seems that my concerns don't have strong grounds and per-CPU
crypto_request allocation can be dropped/removed from tcp_sigpool once
ciphers get crypto_clone_ahash() support.
[1]: https://lore.kernel.org/all/ZDefxOq6Ax0JeTRH@gondor.apana.org.au/T/#u
[2]: https://github.com/0x7f454c46/iperf/tree/tcp-md5-ao
Signed-off-by: Dmitry Safonov <dima@arista.com>
Reviewed-by: Steen Hegelund <Steen.Hegelund@microchip.com>
Acked-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_minisocks.c')
-rw-r--r-- | net/ipv4/tcp_minisocks.c | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c index ace806c5bd0c..3dcb3fc36e64 100644 --- a/net/ipv4/tcp_minisocks.c +++ b/net/ipv4/tcp_minisocks.c @@ -261,10 +261,9 @@ static void tcp_time_wait_init(struct sock *sk, struct tcp_timewait_sock *tcptw) tcptw->tw_md5_key = kmemdup(key, sizeof(*key), GFP_ATOMIC); if (!tcptw->tw_md5_key) return; - if (!tcp_alloc_md5sig_pool()) - goto out_free; if (!static_key_fast_inc_not_disabled(&tcp_md5_needed.key.key)) goto out_free; + tcp_md5_add_sigpool(); } return; out_free: @@ -349,16 +348,26 @@ void tcp_time_wait(struct sock *sk, int state, int timeo) } EXPORT_SYMBOL(tcp_time_wait); +#ifdef CONFIG_TCP_MD5SIG +static void tcp_md5_twsk_free_rcu(struct rcu_head *head) +{ + struct tcp_md5sig_key *key; + + key = container_of(head, struct tcp_md5sig_key, rcu); + kfree(key); + static_branch_slow_dec_deferred(&tcp_md5_needed); + tcp_md5_release_sigpool(); +} +#endif + void tcp_twsk_destructor(struct sock *sk) { #ifdef CONFIG_TCP_MD5SIG if (static_branch_unlikely(&tcp_md5_needed.key)) { struct tcp_timewait_sock *twsk = tcp_twsk(sk); - if (twsk->tw_md5_key) { - kfree_rcu(twsk->tw_md5_key, rcu); - static_branch_slow_dec_deferred(&tcp_md5_needed); - } + if (twsk->tw_md5_key) + call_rcu(&twsk->tw_md5_key->rcu, tcp_md5_twsk_free_rcu); } #endif } |