[src/trunk]: src/usr.sbin/ndp Simplify code to print the router/prefix list: ...

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

details:   https://anonhg.NetBSD.org/src/rev/e5b9afed8c48
branches:  trunk
changeset: 792052:e5b9afed8c48
user:      martin <martin%NetBSD.org@localhost>
date:      Tue Dec 17 20:26:46 2013 +0000

description:
Simplify code to print the router/prefix list: use memcpy and local structs
properly aligned on the stack to decode the binary format passed by the
kernel - instead of (bogusly) assuming the format will obey all local
alignement requirements.

diffstat:

 usr.sbin/ndp/ndp.c |  68 +++++++++++++++++++++++++++---------------------------
 1 files changed, 34 insertions(+), 34 deletions(-)

diffs (133 lines):

diff -r 33325c188ab0 -r e5b9afed8c48 usr.sbin/ndp/ndp.c
--- a/usr.sbin/ndp/ndp.c        Tue Dec 17 20:25:00 2013 +0000
+++ b/usr.sbin/ndp/ndp.c        Tue Dec 17 20:26:46 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: ndp.c,v 1.41 2013/10/19 17:16:25 christos Exp $        */
+/*     $NetBSD: ndp.c,v 1.42 2013/12/17 20:26:46 martin Exp $  */
 /*     $KAME: ndp.c,v 1.121 2005/07/13 11:30:13 keiichi Exp $  */
 
 /*
@@ -1111,9 +1111,8 @@
 {
 #ifdef ICMPV6CTL_ND6_PRLIST
        int mib[] = { CTL_NET, PF_INET6, IPPROTO_ICMPV6, ICMPV6CTL_ND6_PRLIST };
-       char *buf;
-       struct in6_prefix *p, *ep, *n;
-       struct sockaddr_in6 *advrtr;
+       char *buf, *p, *ep;
+       struct in6_prefix pfx;
        size_t l;
        struct timeval tim;
        const int niflags = NI_NUMERICHOST;
@@ -1134,17 +1133,17 @@
                /*NOTREACHED*/
        }
 
-       ep = (struct in6_prefix *)(void *)(buf + l);
-       for (p = (struct in6_prefix *)(void *)buf; p < ep; p = n) {
-               advrtr = (struct sockaddr_in6 *)(void *)(p + 1);
-               n = (struct in6_prefix *)(void *)&advrtr[p->advrtrs];
+       ep = buf + l;
+       for (p = buf; p < ep; ) {
+               memcpy(&pfx, p, sizeof(pfx));
+               p += sizeof(pfx);
 
-               if (getnameinfo((struct sockaddr *)(void *)&p->prefix,
-                   (socklen_t)p->prefix.sin6_len, namebuf, sizeof(namebuf),
+               if (getnameinfo((struct sockaddr*)&pfx.prefix,
+                   (socklen_t)pfx.prefix.sin6_len, namebuf, sizeof(namebuf),
                    NULL, 0, niflags) != 0)
                        (void)strlcpy(namebuf, "?", sizeof(namebuf));
-               (void)printf("%s/%d if=%s\n", namebuf, p->prefixlen,
-                   if_indextoname((unsigned int)p->if_index, ifix_buf));
+               (void)printf("%s/%d if=%s\n", namebuf, pfx.prefixlen,
+                   if_indextoname((unsigned int)pfx.if_index, ifix_buf));
 
                (void)gettimeofday(&tim, 0);
                /*
@@ -1152,54 +1151,56 @@
                 * by origin.  notify the difference to the users.
                 */
                (void)printf("flags=%s%s%s%s%s",
-                   p->raflags.onlink ? "L" : "",
-                   p->raflags.autonomous ? "A" : "",
-                   (p->flags & NDPRF_ONLINK) != 0 ? "O" : "",
-                   (p->flags & NDPRF_DETACHED) != 0 ? "D" : "",
+                   pfx.raflags.onlink ? "L" : "",
+                   pfx.raflags.autonomous ? "A" : "",
+                   (pfx.flags & NDPRF_ONLINK) != 0 ? "O" : "",
+                   (pfx.flags & NDPRF_DETACHED) != 0 ? "D" : "",
 #ifdef NDPRF_HOME
-                   (p->flags & NDPRF_HOME) != 0 ? "H" : ""
+                   (pfx.flags & NDPRF_HOME) != 0 ? "H" : ""
 #else
                    ""
 #endif
                    );
-               if (p->vltime == ND6_INFINITE_LIFETIME)
+               if (pfx.vltime == ND6_INFINITE_LIFETIME)
                        (void)printf(" vltime=infinity");
                else
-                       (void)printf(" vltime=%lu", (unsigned long)p->vltime);
-               if (p->pltime == ND6_INFINITE_LIFETIME)
+                       (void)printf(" vltime=%lu", (unsigned long)pfx.vltime);
+               if (pfx.pltime == ND6_INFINITE_LIFETIME)
                        (void)printf(", pltime=infinity");
                else
-                       (void)printf(", pltime=%lu", (unsigned long)p->pltime);
-               if (p->expire == 0)
+                       (void)printf(", pltime=%lu", (unsigned long)pfx.pltime);
+               if (pfx.expire == 0)
                        (void)printf(", expire=Never");
-               else if (p->expire >= tim.tv_sec)
+               else if (pfx.expire >= tim.tv_sec)
                        (void)printf(", expire=%s",
-                           sec2str(p->expire - tim.tv_sec));
+                           sec2str(pfx.expire - tim.tv_sec));
                else
                        (void)printf(", expired");
-               (void)printf(", ref=%d", p->refcnt);
+               (void)printf(", ref=%d", pfx.refcnt);
                (void)printf("\n");
                /*
                 * "advertising router" list is meaningful only if the prefix
                 * information is from RA.
                 */
-               if (p->advrtrs) {
+               if (pfx.advrtrs) {
                        int j;
-                       struct sockaddr_in6 *sin6;
+                       struct sockaddr_in6 sin6;
 
-                       sin6 = advrtr;
                        (void)printf("  advertised by\n");
-                       for (j = 0; j < p->advrtrs; j++) {
+                       for (j = 0; j < pfx.advrtrs && p <= ep; j++) {
                                struct in6_nbrinfo *nbi;
 
-                               if (getnameinfo((struct sockaddr *)(void *)sin6,
-                                   (socklen_t)sin6->sin6_len, namebuf,
+                               memcpy(&sin6, p, sizeof(sin6));
+                               p += sizeof(sin6);
+
+                               if (getnameinfo((struct sockaddr *)&sin6,
+                                   (socklen_t)sin6.sin6_len, namebuf,
                                    sizeof(namebuf), NULL, 0, ninflags) != 0)
                                        (void)strlcpy(namebuf, "?", sizeof(namebuf));
                                (void)printf("    %s", namebuf);
 
-                               nbi = getnbrinfo(&sin6->sin6_addr,
-                                   (unsigned int)p->if_index, 0);
+                               nbi = getnbrinfo(&sin6.sin6_addr,
+                                   (unsigned int)pfx.if_index, 0);
                                if (nbi) {
                                        switch (nbi->state) {
                                        case ND6_LLINFO_REACHABLE:
@@ -1213,7 +1214,6 @@
                                        }
                                } else
                                        (void)printf(" (no neighbor state)\n");
-                               sin6++;
                        }
                } else
                        (void)printf("  No advertising router\n");