Re: Unlock nd6_ioctl(), push kernel lock into in6_ioctl_{get,change_ifaddr}()

[Klemens Nanni]

On Wed, Nov 30, 2022 at 02:25:46AM +0300, Vitaliy Makkoveev wrote:
> I like to have current "error =" notation for both mrt6_ioctl()
> and in6_ioctl() within in6_control().

Alright.

> Also, `data’ passed to in6_ioctl_change_ifaddr() is the local
> variable, kernel lock could be pushed deep down, just before
> netlock.

Sure.

OK?
---
Neighbour Discovery information is protected by the net lock, as
documented in nd6.h struct nd_ifinfo.

ndp(8) is the only SIOCGIFINFO_IN6 and SIOCGNBRINFO_IN6 user in base.

nd6_lookup(), also used in ICMP6 input and IPv6 forwarding, only needs
the net lock.

diff --git a/sys/netinet6/in6.c b/sys/netinet6/in6.c
index 44dfa3488ef..a34e3860916 100644
--- a/sys/netinet6/in6.c
+++ b/sys/netinet6/in6.c
@@ -213,9 +213,7 @@ in6_control(struct socket *so, u_long cmd, caddr_t data, 
struct ifnet *ifp)
                break;
 #endif /* MROUTING */
        default:
-               KERNEL_LOCK();
                error = in6_ioctl(cmd, data, ifp, privileged);
-               KERNEL_UNLOCK();
                break;
        }
 
@@ -296,6 +294,7 @@ in6_ioctl_change_ifaddr(u_long cmd, caddr_t data, struct 
ifnet *ifp)
                        return (error);
        }
 
+       KERNEL_LOCK();
        NET_LOCK();
 
        if (sa6 != NULL) {
@@ -402,6 +401,7 @@ in6_ioctl_change_ifaddr(u_long cmd, caddr_t data, struct 
ifnet *ifp)
 
 err:
        NET_UNLOCK();
+       KERNEL_UNLOCK();
        return (error);
 }
 
@@ -422,6 +422,7 @@ in6_ioctl_get(u_long cmd, caddr_t data, struct ifnet *ifp)
                        return (error);
        }
 
+       KERNEL_LOCK();
        NET_LOCK_SHARED();
 
        if (sa6 != NULL) {
@@ -517,6 +518,7 @@ in6_ioctl_get(u_long cmd, caddr_t data, struct ifnet *ifp)
 
 err:
        NET_UNLOCK_SHARED();
+       KERNEL_UNLOCK();
        return (error);
 }