On Fri, Sep 13, 2024 at 10:39:20AM +0100, Tiago Lam wrote:
> This follows the same rationale provided for the ipv4 counterpart, where
> it now runs a reverse socket lookup when source addresses and/or ports
> are changed, on sendmsg, to check whether egress traffic should be
> allowed to go through or not.
>
> As with ipv4, the ipv6 sendmsg path is also extended here to support the
> IPV6_ORIGDSTADDR ancilliary message to be able to specify a source
Hi Tiago Lam,
Some minor nits from my side.
ancilliary -> ancillary
Likewise in patch 3/3.
Flagged by checkpatch.pl --codespell
> address/port.
>
> Suggested-by: Jakub Sitnicki <ja...@cloudflare.com>
> Signed-off-by: Tiago Lam <tiago...@cloudflare.com>
> ---
> net/ipv6/datagram.c | 76
> +++++++++++++++++++++++++++++++++++++++++++++++++++++
> net/ipv6/udp.c | 8 ++++--
> 2 files changed, 82 insertions(+), 2 deletions(-)
>
> diff --git a/net/ipv6/datagram.c b/net/ipv6/datagram.c
> index fff78496803d..4214dda1c320 100644
> --- a/net/ipv6/datagram.c
> +++ b/net/ipv6/datagram.c
> @@ -756,6 +756,27 @@ void ip6_datagram_recv_ctl(struct sock *sk, struct
> msghdr *msg,
> }
> EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
>
> +static inline bool reverse_sk_lookup(struct flowi6 *fl6, struct sock *sk,
> + struct in6_addr *saddr, __be16 sport)
> +{
> + if (static_branch_unlikely(&bpf_sk_lookup_enabled) &&
> + (saddr && sport) &&
> + (ipv6_addr_cmp(&sk->sk_v6_rcv_saddr, saddr) ||
> inet_sk(sk)->inet_sport != sport)) {
Please consider, where it can trivially be achieved, limiting Networking
code to 80 columns wide.
Checkpatch can be run with a flag to check for this.
> + struct sock *sk_egress;
> +
> + bpf_sk_lookup_run_v6(sock_net(sk), IPPROTO_UDP, &fl6->daddr,
> fl6->fl6_dport,
> + saddr, ntohs(sport), 0, &sk_egress);
> + if (!IS_ERR_OR_NULL(sk_egress) &&
> + atomic64_read(&sk_egress->sk_cookie) ==
> atomic64_read(&sk->sk_cookie))
> + return true;
> +
> + net_info_ratelimited("No reverse socket lookup match for local
> addr %pI6:%d remote addr %pI6:%d\n",
> + &saddr, ntohs(sport), &fl6->daddr,
> ntohs(fl6->fl6_dport));
> + }
> +
> + return false;
> +}
> +
> int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
> struct msghdr *msg, struct flowi6 *fl6,
> struct ipcm6_cookie *ipc6)
...
