[src/trunk]: src/sys/netinet6 Instead of voodo casts use simple byte pointer ...

[martin <martin%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/ab6a0e799c3b
branches:  trunk
changeset: 325311:ab6a0e799c3b
user:      martin <martin%NetBSD.org@localhost>
date:      Tue Dec 17 20:25:00 2013 +0000

description:
Instead of voodo casts use simple byte pointer arithmetic and memcpy to
create the "packed" binary format we pass out to userland when querying
the router/prefix list.

diffstat:

 sys/netinet6/nd6.c |  78 ++++++++++++++++++++++++++++-------------------------
 1 files changed, 41 insertions(+), 37 deletions(-)

diffs (146 lines):

diff -r 1f207efb1cb1 -r ab6a0e799c3b sys/netinet6/nd6.c
--- a/sys/netinet6/nd6.c        Tue Dec 17 17:13:46 2013 +0000
+++ b/sys/netinet6/nd6.c        Tue Dec 17 20:25:00 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: nd6.c,v 1.145 2013/05/21 08:37:27 roy Exp $    */
+/*     $NetBSD: nd6.c,v 1.146 2013/12/17 20:25:00 martin Exp $ */
 /*     $KAME: nd6.c,v 1.279 2002/06/08 11:16:51 itojun Exp $   */
 
 /*
@@ -31,7 +31,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: nd6.c,v 1.145 2013/05/21 08:37:27 roy Exp $");
+__KERNEL_RCSID(0, "$NetBSD: nd6.c,v 1.146 2013/12/17 20:25:00 martin Exp $");
 
 #include "opt_ipsec.h"
 
@@ -2385,44 +2385,43 @@
 {
        int error = 0, s;
        struct nd_prefix *pr;
-       struct in6_prefix *p = NULL;
-       struct in6_prefix *pe = NULL;
+       uint8_t *p = NULL, *ps = NULL;
+       uint8_t *pe = NULL;
        size_t l;
 
        s = splsoftnet();
 
        if (oldp) {
-               p = (struct in6_prefix *)oldp;
-               pe = (struct in6_prefix *)((char *)oldp + *oldlenp);
+               ps = p = (uint8_t*)oldp;
+               pe = (uint8_t*)oldp + *oldlenp;
        }
        l = 0;
 
        LIST_FOREACH(pr, &nd_prefix, ndpr_entry) {
                u_short advrtrs;
-               size_t advance;
-               struct sockaddr_in6 *sin6;
-               struct sockaddr_in6 *s6;
+               struct sockaddr_in6 sin6;
                struct nd_pfxrouter *pfr;
+               struct in6_prefix pfx;
 
-               if (oldp && p + 1 <= pe)
+               if (oldp && p + sizeof(struct in6_prefix) <= pe)
                {
-                       memset(p, 0, sizeof(*p));
-                       sin6 = (struct sockaddr_in6 *)(p + 1);
+                       memset(&pfx, 0, sizeof(pfx));
+                       ps = p;
+                       pfx.prefix = pr->ndpr_prefix;
 
-                       p->prefix = pr->ndpr_prefix;
-                       if (sa6_recoverscope(&p->prefix)) {
+                       if (sa6_recoverscope(&pfx.prefix)) {
                                log(LOG_ERR,
                                    "scope error in prefix list (%s)\n",
-                                   ip6_sprintf(&p->prefix.sin6_addr));
+                                   ip6_sprintf(&pfx.prefix.sin6_addr));
                                /* XXX: press on... */
                        }
-                       p->raflags = pr->ndpr_raf;
-                       p->prefixlen = pr->ndpr_plen;
-                       p->vltime = pr->ndpr_vltime;
-                       p->pltime = pr->ndpr_pltime;
-                       p->if_index = pr->ndpr_ifp->if_index;
+                       pfx.raflags = pr->ndpr_raf;
+                       pfx.prefixlen = pr->ndpr_plen;
+                       pfx.vltime = pr->ndpr_vltime;
+                       pfx.pltime = pr->ndpr_pltime;
+                       pfx.if_index = pr->ndpr_ifp->if_index;
                        if (pr->ndpr_vltime == ND6_INFINITE_LIFETIME)
-                               p->expire = 0;
+                               pfx.expire = 0;
                        else {
                                time_t maxexpire;
 
@@ -2432,43 +2431,48 @@
                                    ((sizeof(maxexpire) * 8) - 1));
                                if (pr->ndpr_vltime <
                                    maxexpire - pr->ndpr_lastupdate) {
-                                       p->expire = pr->ndpr_lastupdate +
+                                       pfx.expire = pr->ndpr_lastupdate +
                                                pr->ndpr_vltime;
                                } else
-                                       p->expire = maxexpire;
+                                       pfx.expire = maxexpire;
                        }
-                       p->refcnt = pr->ndpr_refcnt;
-                       p->flags = pr->ndpr_stateflags;
-                       p->origin = PR_ORIG_RA;
+                       pfx.refcnt = pr->ndpr_refcnt;
+                       pfx.flags = pr->ndpr_stateflags;
+                       pfx.origin = PR_ORIG_RA;
+
+                       p += sizeof(pfx); l += sizeof(pfx);
+
                        advrtrs = 0;
                        LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry) {
-                               if ((void *)&sin6[advrtrs + 1] > (void *)pe) {
+                               if (p + sizeof(sin6) > pe) {
                                        advrtrs++;
                                        continue;
                                }
-                               s6 = &sin6[advrtrs];
-                               sockaddr_in6_init(s6, &pfr->router->rtaddr,
+
+                               sockaddr_in6_init(&sin6, &pfr->router->rtaddr,
                                    0, 0, 0);
-                               if (sa6_recoverscope(s6)) {
+                               if (sa6_recoverscope(&sin6)) {
                                        log(LOG_ERR,
                                            "scope error in "
                                            "prefix list (%s)\n",
                                            ip6_sprintf(&pfr->router->rtaddr));
                                }
                                advrtrs++;
+                               memcpy(p, &sin6, sizeof(sin6));
+                               p += sizeof(sin6);
+                               l += sizeof(sin6);
                        }
-                       p->advrtrs = advrtrs;
+                       pfx.advrtrs = advrtrs;
+                       memcpy(ps, &pfx, sizeof(pfx));
                }
                else {
+                       l += sizeof(pfx);
                        advrtrs = 0;
-                       LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry)
+                       LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry) {
                                advrtrs++;
+                               l += sizeof(sin6);
+                       }
                }
-
-               advance = sizeof(*p) + sizeof(*sin6) * advrtrs;
-               l += advance;
-               if (p)
-                       p = (struct in6_prefix *)((char *)p + advance);
        }
 
        if (oldp) {