"Push kernel lock into in6_ioctl()" on tech@ talks about ND6 locking,
here is one cleanup and one documentation change (squashed) for this.

---
Remove struct nd_ifinfo's unused .initialized member

Added/set in 2002 nd6.h r1.17/nd6.c r1.42, respectively, but never read:
    attach nd_ifinfo structure to if_afdata.
    split IPv6 MTU (advertised by RA) from real link MTU.
    sync with kame

Outside of _KERNEL, but nothing in base uses it, either.
===
Document struct nd_ifinfo protection, remove unused initialized member

IPv6 Neighbour Discovery information is fully protected by the net lock.

All access to struct ifnet's member *if_nd is read-only, with the one
write exception being nd6_slowtimo() updating ND information.

The output of `grep -srw -e if_nd -e nd6if /sys/' shows these and fits
on a screen, probably with enough -C context to show locking details.
---

Feedback? Objection? OK?

diff --git a/sys/netinet6/nd6.c b/sys/netinet6/nd6.c
index d6ccfd3a272..df9b25f3c39 100644
--- a/sys/netinet6/nd6.c
+++ b/sys/netinet6/nd6.c
@@ -133,8 +133,6 @@ nd6_ifattach(struct ifnet *ifp)
 
        nd = malloc(sizeof(*nd), M_IP6NDP, M_WAITOK | M_ZERO);
 
-       nd->initialized = 1;
-
        nd->basereachable = REACHABLE_TIME;
        nd->reachable = ND_COMPUTE_RTIME(nd->basereachable);
        nd->retrans = RETRANS_TIMER;
diff --git a/sys/netinet6/nd6.h b/sys/netinet6/nd6.h
index 52c1e31da78..ff80d75a351 100644
--- a/sys/netinet6/nd6.h
+++ b/sys/netinet6/nd6.h
@@ -43,12 +43,16 @@
 #define ND6_LLINFO_DELAY       3
 #define ND6_LLINFO_PROBE       4
 
+/*
+ *  Locks used to protect struct members in this file:
+ *     N       net lock
+ */
+
 struct nd_ifinfo {
-       u_int32_t basereachable;        /* BaseReachableTime */
-       u_int32_t reachable;            /* Reachable Time */
-       u_int32_t retrans;              /* Retrans Timer */
-       int recalctm;                   /* BaseReacable re-calculation timer */
-       u_int8_t initialized; /* Flag to see the entry is initialized */
+       u_int32_t basereachable;        /* [N] BaseReachableTime */
+       u_int32_t reachable;            /* [N] Reachable Time */
+       u_int32_t retrans;              /* [N] Retrans Timer */
+       int recalctm;                   /* [N] BaseReachable recalc timer */
 };
 
 struct in6_nbrinfo {

Reply via email to