Re: [PATCH v12 net-next 06/23] net/tcp: Add TCP-AO sign to outgoing packets
From: Paolo Abeni <pabeni@redhat.com>
Date: 2023-09-21 21:52:04
Also in:
lkml
On Mon, 2023-09-18 at 20:00 +0100, Dmitry Safonov wrote:
quoted hunk ↗ jump to hunk
@@ -615,19 +616,43 @@ static void bpf_skops_write_hdr_opt(struct sock *sk, struct sk_buff *skb, * (but it may well be that other scenarios fail similarly). */ static void tcp_options_write(struct tcphdr *th, struct tcp_sock *tp, - struct tcp_out_options *opts) + struct tcp_out_options *opts, + struct tcp_key *key) { __be32 *ptr = (__be32 *)(th + 1); u16 options = opts->options; /* mungable copy */ - if (unlikely(OPTION_MD5 & options)) { + if (tcp_key_is_md5(key)) { *ptr++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG); /* overload cookie hash location */ opts->hash_location = (__u8 *)ptr; ptr += 4; - } + } else if (tcp_key_is_ao(key)) { +#ifdef CONFIG_TCP_AO + struct tcp_ao_key *rnext_key; + struct tcp_ao_info *ao_info; + u8 maclen; + ao_info = rcu_dereference_check(tp->ao_info, + lockdep_sock_is_held(&tp->inet_conn.icsk_inet.sk)); + rnext_key = READ_ONCE(ao_info->rnext_key); + if (WARN_ON_ONCE(!rnext_key)) + goto out_ao; + maclen = tcp_ao_maclen(key->ao_key);
It looks like only TCP_AO really accesses 'key', and TCP_AO can easily
fetch it from ao_info. Can the AO key change in between
tcp_get_current_key() and here?
Otherwise I think it would be better omitting the 'key' argument here
and use the 'options' flag to pick TCP_AO vs MD5.
And:
if (unlikely(OPTION_MD5 & options)) {
could possibly be moved under a CONFIG_MD5 compiler conditional.
Cheers,
Paolo