[src/trunk]: src/sys/netinet6 use ip6_{last, next}hdr in icmp6 inbound packet ...

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

details:   https://anonhg.NetBSD.org/src/rev/a0e787e03cae
branches:  trunk
changeset: 483974:a0e787e03cae
user:      itojun <itojun%NetBSD.org@localhost>
date:      Wed Mar 22 04:42:01 2000 +0000

description:
use ip6_{last,next}hdr in icmp6 inbound packet parsing.

diffstat:

 sys/netinet6/icmp6.c |  111 +++++++++++++++++----------------------------------
 1 files changed, 37 insertions(+), 74 deletions(-)

diffs (148 lines):

diff -r c40e3390b0ce -r a0e787e03cae sys/netinet6/icmp6.c
--- a/sys/netinet6/icmp6.c      Wed Mar 22 03:27:56 2000 +0000
+++ b/sys/netinet6/icmp6.c      Wed Mar 22 04:42:01 2000 +0000
@@ -1,5 +1,5 @@
-/*     $NetBSD: icmp6.c,v 1.26 2000/03/01 12:49:44 itojun Exp $        */
-/*     $KAME: icmp6.c,v 1.71 2000/02/28 09:25:42 jinmei Exp $  */
+/*     $NetBSD: icmp6.c,v 1.27 2000/03/22 04:42:01 itojun Exp $        */
+/*     $KAME: icmp6.c,v 1.75 2000/03/11 09:32:17 itojun Exp $  */
 
 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -154,7 +154,7 @@
        struct icmp6_hdr *icmp6;
        u_int preplen;
        int off;
-       u_char nxt;
+       int nxt;
 
        icmp6stat.icp6s_error++;
 
@@ -192,86 +192,41 @@
                goto freeit;
 
        /*
-        * If the erroneous packet is also an ICMP error, discard it.
+        * If we are about to send ICMPv6 against ICMPv6 error/redirect,
+        * don't do it.
         */
-       off = sizeof(struct ip6_hdr);
-       nxt = oip6->ip6_nxt;
-       while (1) {             /* XXX: should avoid inf. loop explicitly? */
-               struct ip6_ext *ip6e;
+       nxt = -1;
+       off = ip6_lasthdr(m, sizeof(struct ip6_hdr), oip6->ip6_nxt, &nxt);
+       if (off >= 0 && nxt == IPPROTO_ICMPV6) {
                struct icmp6_hdr *icp;
 
-               switch(nxt) {
-               case IPPROTO_IPV6:
-               case IPPROTO_IPV4:
-               case IPPROTO_UDP:
-               case IPPROTO_TCP:
-               case IPPROTO_ESP:
-               case IPPROTO_IPCOMP:
-               case IPPROTO_FRAGMENT:
-                       /*
-                        * ICMPv6 error must not be fragmented.
-                        * XXX: but can we trust the sender?
-                        */
-               default:
-                       /* What if unknown header followed by ICMP error? */
-                       goto generate;
-               case IPPROTO_ICMPV6:
 #ifndef PULLDOWN_TEST
-                       IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), );
-                       icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
+               IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct icmp6_hdr), );
+               icp = (struct icmp6_hdr *)(mtod(m, caddr_t) + off);
 #else
-                       IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
-                               sizeof(*icp));
-                       if (icp == NULL) {
-                               icmp6stat.icp6s_tooshort++;
-                               return;
-                       }
+               IP6_EXTHDR_GET(icp, struct icmp6_hdr *, m, off,
+                       sizeof(*icp));
+               if (icp == NULL) {
+                       icmp6stat.icp6s_tooshort++;
+                       return;
+               }
 #endif
-                       if (icp->icmp6_type < ICMP6_ECHO_REQUEST
-                        || icp->icmp6_type == ND_REDIRECT) {
-                               /*
-                                * ICMPv6 error
-                                * Special case: for redirect (which is
-                                * informational) we must not send icmp6 error.
-                                */
-                               icmp6stat.icp6s_canterror++;
-                               goto freeit;
-                       } else {
-                               /* ICMPv6 informational */
-                               goto generate;
-                       }
-               case IPPROTO_HOPOPTS:
-               case IPPROTO_DSTOPTS:
-               case IPPROTO_ROUTING:
-               case IPPROTO_AH:
-#ifndef PULLDOWN_TEST
-                       IP6_EXTHDR_CHECK(m, 0, off + sizeof(struct ip6_ext), );
-                       ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off);
-#else
-                       IP6_EXTHDR_GET(ip6e, struct ip6_ext *, m, off,
-                               sizeof(*ip6e));
-                       if (ip6e == NULL) {
-                               /*XXX stat */
-                               return;
-                       }
-#endif
-                       if (nxt == IPPROTO_AH)
-                               off += (ip6e->ip6e_len + 2) << 2;
-                       else
-                               off += (ip6e->ip6e_len + 1) << 3;
-                       nxt = ip6e->ip6e_nxt;
-                       break;
+               if (icp->icmp6_type < ICMP6_ECHO_REQUEST ||
+                   icp->icmp6_type == ND_REDIRECT) {
+                       /*
+                        * ICMPv6 error
+                        * Special case: for redirect (which is
+                        * informational) we must not send icmp6 error.
+                        */
+                       icmp6stat.icp6s_canterror++;
+                       goto freeit;
+               } else {
+                       /* ICMPv6 informational - send the error */
                }
+       } else {
+               /* non-ICMPv6 - send the error */
        }
 
-  freeit:
-       /*
-        * If we can't tell wheter or not we can generate ICMP6, free it.
-        */
-       m_freem(m);
-       return;
-
-  generate:
        oip6 = mtod(m, struct ip6_hdr *); /* adjust pointer */
 
        /* Finally, do rate limitation check. */
@@ -312,6 +267,14 @@
 
        icmp6stat.icp6s_outhist[type]++;
        icmp6_reflect(m, sizeof(struct ip6_hdr)); /*header order: IPv6 - ICMPv6*/
+
+       return;
+
+  freeit:
+       /*
+        * If we can't tell wheter or not we can generate ICMP6, free it.
+        */
+       m_freem(m);
 }
 
 /*