2022-11-24 12:04:34

by Richard Gobert

Subject: [PATCH] net: setsockopt: fix IPV6_UNICAST_IF option for connected sockets

Change the behaviour of ip6_datagram_connect to consider the interface
set by the IPV6_UNICAST_IF socket option, similarly to udpv6_sendmsg.

This change is the IPv6 counterpart of the fix for IP_UNICAST_IF.
The tests introduced by that patch showed that the incorrect
behavior is present in IPv6 as well.
This patch fixes the broken test.

Reported-by: kernel test robot <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

Signed-off-by: Richard Gobert <[email protected]>
---
net/ipv6/datagram.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/net/ipv6/datagram.c b/net/ipv6/datagram.c
index 7c7155b48f17..c3999f9e3545 100644
--- a/net/ipv6/datagram.c
+++ b/net/ipv6/datagram.c
@@ -42,24 +42,30 @@ static void ip6_datagram_flow_key_init(struct flowi6 *fl6, struct sock *sk)
{
struct inet_sock *inet = inet_sk(sk);
struct ipv6_pinfo *np = inet6_sk(sk);
+ int oif;

memset(fl6, 0, sizeof(*fl6));
fl6->flowi6_proto = sk->sk_protocol;
fl6->daddr = sk->sk_v6_daddr;
fl6->saddr = np->saddr;
- fl6->flowi6_oif = sk->sk_bound_dev_if;
+ oif = sk->sk_bound_dev_if;
fl6->flowi6_mark = sk->sk_mark;
fl6->fl6_dport = inet->inet_dport;
fl6->fl6_sport = inet->inet_sport;
fl6->flowlabel = np->flow_label;
fl6->flowi6_uid = sk->sk_uid;

- if (!fl6->flowi6_oif)
- fl6->flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
+ if (!oif)
+ oif = np->sticky_pktinfo.ipi6_ifindex;

- if (!fl6->flowi6_oif && ipv6_addr_is_multicast(&fl6->daddr))
- fl6->flowi6_oif = np->mcast_oif;
+ if (!oif) {
+ if (ipv6_addr_is_multicast(&fl6->daddr))
+ oif = np->mcast_oif;
+ else
+ oif = np->ucast_oif;
+ }

+ fl6->flowi6_oif = oif;
security_sk_classify_flow(sk, flowi6_to_flowi_common(fl6));
}

--
2.36.1

2022-11-25 04:34:37

by David Ahern

Subject: Re: [PATCH] net: setsockopt: fix IPV6_UNICAST_IF option for connected sockets

On 11/24/22 4:48 AM, Richard Gobert wrote:
> Change the behaviour of ip6_datagram_connect to consider the interface
> set by the IPV6_UNICAST_IF socket option, similarly to udpv6_sendmsg.
>
> This change is the IPv6 counterpart of the fix for IP_UNICAST_IF.
> The tests introduced by that patch showed that the incorrect
> behavior is present in IPv6 as well.
> This patch fixes the broken test.
>
> Reported-by: kernel test robot <[email protected]>
> Link: https://lore.kernel.org/r/[email protected]
>

Fixes tag here.

> Signed-off-by: Richard Gobert <[email protected]>
> ---
> net/ipv6/datagram.c | 16 +++++++++++-----
> 1 file changed, 11 insertions(+), 5 deletions(-)
>
> diff --git a/net/ipv6/datagram.c b/net/ipv6/datagram.c
> index 7c7155b48f17..c3999f9e3545 100644
> --- a/net/ipv6/datagram.c
> +++ b/net/ipv6/datagram.c
> @@ -42,24 +42,30 @@ static void ip6_datagram_flow_key_init(struct flowi6 *fl6, struct sock *sk)
> {
> struct inet_sock *inet = inet_sk(sk);
> struct ipv6_pinfo *np = inet6_sk(sk);
> + int oif;

int oif = sk->sk_bound_dev_if;
>
> memset(fl6, 0, sizeof(*fl6));
> fl6->flowi6_proto = sk->sk_protocol;
> fl6->daddr = sk->sk_v6_daddr;
> fl6->saddr = np->saddr;
> - fl6->flowi6_oif = sk->sk_bound_dev_if;
> + oif = sk->sk_bound_dev_if;

and then drop this line in the middle of all of the fl6 setup.

> fl6->flowi6_mark = sk->sk_mark;
> fl6->fl6_dport = inet->inet_dport;
> fl6->fl6_sport = inet->inet_sport;
> fl6->flowlabel = np->flow_label;
> fl6->flowi6_uid = sk->sk_uid;
>
> - if (!fl6->flowi6_oif)
> - fl6->flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
> + if (!oif)
> + oif = np->sticky_pktinfo.ipi6_ifindex;
>
> - if (!fl6->flowi6_oif && ipv6_addr_is_multicast(&fl6->daddr))
> - fl6->flowi6_oif = np->mcast_oif;
> + if (!oif) {
> + if (ipv6_addr_is_multicast(&fl6->daddr))
> + oif = np->mcast_oif;
> + else
> + oif = np->ucast_oif;
> + }
>
> + fl6->flowi6_oif = oif;
> security_sk_classify_flow(sk, flowi6_to_flowi_common(fl6));
> }
>

thanks for the fix.

Besides the nit,
Reviewed-by: David Ahern <[email protected]>