Re: [PATCH net-next v11 14/23] ovpn: implement peer lookup logic

From: Sabrina Dubroca
Date: Mon Nov 04 2024 - 06:31:42 EST


2024-10-29, 11:47:27 +0100, Antonio Quartulli wrote:
> struct ovpn_peer *ovpn_peer_get_by_transp_addr(struct ovpn_struct *ovpn,
> struct sk_buff *skb)
> {
> - struct ovpn_peer *peer = NULL;
> + struct ovpn_peer *tmp, *peer = NULL;
> struct sockaddr_storage ss = { 0 };
> + struct hlist_nulls_head *nhead;
> + struct hlist_nulls_node *ntmp;
> + size_t sa_len;
>
> if (unlikely(!ovpn_peer_skb_to_sockaddr(skb, &ss)))
> return NULL;
>
> if (ovpn->mode == OVPN_MODE_P2P)
> - peer = ovpn_peer_get_by_transp_addr_p2p(ovpn, &ss);
> + return ovpn_peer_get_by_transp_addr_p2p(ovpn, &ss);
> +
> + switch (ss.ss_family) {
> + case AF_INET:
> + sa_len = sizeof(struct sockaddr_in);
> + break;
> + case AF_INET6:
> + sa_len = sizeof(struct sockaddr_in6);
> + break;
> + default:
> + return NULL;
> + }

You could get rid of that switch by having ovpn_peer_skb_to_sockaddr
also set sa_len (or return 0/the size).

> +
> + nhead = ovpn_get_hash_head(ovpn->peers->by_transp_addr, &ss, sa_len);
> +
> + rcu_read_lock();
> + hlist_nulls_for_each_entry_rcu(tmp, ntmp, nhead,
> + hash_entry_transp_addr) {

I think that's missing the retry in case we ended up in the wrong
bucket due to a peer rehash?

> + if (!ovpn_peer_transp_match(tmp, &ss))
> + continue;
> +
> + if (!ovpn_peer_hold(tmp))
> + continue;
> +
> + peer = tmp;
> + break;
> + }
> + rcu_read_unlock();
>
> return peer;
> }

--
Sabrina