Fix deletion of ifaddr lle entries when deleting prefix from interface in

  down state.

Regression appeared in r287789, where the "prefix has no corresponding
  installed route" case was forgotten. Additionally, lltable_delete_addr()
  was called with incorrect byte order (default is network for lltable code).
While here, improve comments on given cases and byte order.

PR:		203573
Submitted by:	phk

diff --git a/sys/netinet/in.c b/sys/netinet/in.c
index 1441936c38085555d68737186a91a3da43ed5ad1..2607a1750ffdf54d96216ab0a2006d71e8abda6c 100644 (file)
--- a/sys/netinet/in.c
+++ b/sys/netinet/in.c
@@ -734,14 +734,10 @@ in_scrubprefixlle(struct in_ifaddr *ia, int all, u_int flags)
        struct sockaddr *saddr, *smask;
        struct ifnet *ifp;
 
-       /*
-        * remove all L2 entries on the given prefix
-        */
        saddr = (struct sockaddr *)&addr;
        bzero(&addr, sizeof(addr));
        addr.sin_len = sizeof(addr);
        addr.sin_family = AF_INET;
-       addr.sin_addr.s_addr = ntohl(ia->ia_addr.sin_addr.s_addr);
        smask = (struct sockaddr *)&mask;
        bzero(&mask, sizeof(mask));
        mask.sin_len = sizeof(mask);
@@ -749,10 +745,21 @@ in_scrubprefixlle(struct in_ifaddr *ia, int all, u_int flags)
        mask.sin_addr.s_addr = ia->ia_subnetmask;
        ifp = ia->ia_ifp;
 
-       if (all)
+       if (all) {
+
+               /*
+                * Remove all L2 entries matching given prefix.
+                * Convert address to host representation to avoid
+                * doing this on every callback. ia_subnetmask is already
+                * stored in host representation.
+                */
+               addr.sin_addr.s_addr = ntohl(ia->ia_addr.sin_addr.s_addr);
                lltable_prefix_free(AF_INET, saddr, smask, flags);
-       else
+       } else {
+               /* Remove interface address only */
+               addr.sin_addr.s_addr = ia->ia_addr.sin_addr.s_addr;
                lltable_delete_addr(LLTABLE(ifp), LLE_IFADDR, saddr);
+       }
 }
 
 /*
@@ -808,6 +815,14 @@ in_scrubprefix(struct in_ifaddr *target, u_int flags)
                fibnum = V_rt_add_addr_allfibs ? RT_ALL_FIBS :
                        target->ia_ifp->if_fib;
                rt_addrmsg(RTM_DELETE, &target->ia_ifa, fibnum);
+       
+               /*
+                * Removing address from !IFF_UP interface or
+                * prefix which exists on other interface (along with route).
+                * No entries should exist here except target addr.
+                * Given that, delete this entry only.
+                */
+               in_scrubprefixlle(target, 0, flags);
                return (0);
        }