[src/trunk]: src/sys/netmpls reserve space for ICMP header accordingly to RFC...

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

details:   https://anonhg.NetBSD.org/src/rev/7214e6d8ff8d
branches:  trunk
changeset: 789116:7214e6d8ff8d
user:      kefren <kefren%NetBSD.org@localhost>
date:      Wed Aug 07 06:55:00 2013 +0000

description:
reserve space for ICMP header accordingly to RFC4884

diffstat:

 sys/netmpls/mpls_ttl.c |  23 ++++++++++++-----------
 1 files changed, 12 insertions(+), 11 deletions(-)

diffs (68 lines):

diff -r 5a0879766682 -r 7214e6d8ff8d sys/netmpls/mpls_ttl.c
--- a/sys/netmpls/mpls_ttl.c    Wed Aug 07 06:09:32 2013 +0000
+++ b/sys/netmpls/mpls_ttl.c    Wed Aug 07 06:55:00 2013 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: mpls_ttl.c,v 1.3 2010/07/05 09:54:26 kefren Exp $ */
+/*     $NetBSD: mpls_ttl.c,v 1.4 2013/08/07 06:55:00 kefren Exp $ */
 
 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -97,7 +97,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: mpls_ttl.c,v 1.3 2010/07/05 09:54:26 kefren Exp $");
+__KERNEL_RCSID(0, "$NetBSD: mpls_ttl.c,v 1.4 2013/08/07 06:55:00 kefren Exp $");
 
 #include "opt_inet.h"
 #include "opt_mpls.h"
@@ -165,8 +165,9 @@
 static bool ip4_check(struct mbuf *);
 
 /*
- * Reference: http://tools.ietf.org/html/rfc4950
+ * References: RFC 4884 and RFC 4950
  * This should be in sync with icmp_error() in sys/netinet/ip_icmp.c
+ * XXX: is called only for ICMP_TIMXCEED_INTRANS but code is too general
  */
 
 static void
@@ -238,7 +239,8 @@
                mblen += m->m_len;
        icmplen = min(mblen, icmplen);
 
-       packetlen = sizeof(struct ip) + ICMP_EXT_OFFSET + sizeof(mpls_icmp_ext);
+       packetlen = sizeof(struct ip) + offsetof(struct icmp, icmp_ip) +
+           ICMP_EXT_OFFSET + sizeof(mpls_icmp_ext);
 
        /*
         * As we are not required to return everything we have,
@@ -265,13 +267,12 @@
        m->m_len = packetlen;
        if ((m->m_flags & M_EXT) == 0)
                MH_ALIGN(m, m->m_len);
-       else {
-               m->m_data += sizeof(struct ip);
-               m->m_len -= sizeof(struct ip);
-       }
+       m->m_data += sizeof(struct ip);
+       m->m_len -= sizeof(struct ip);
+
        icp = mtod(m, struct icmp *);
        if ((u_int)type > ICMP_MAXTYPE)
-               panic("icmp error");
+               panic("icmp error (mpls_ttl)");
        ICMP_STATINC(ICMP_STAT_OUTHIST + type);
        icp->icmp_type = type;
        if (type == ICMP_REDIRECT)
@@ -377,8 +378,8 @@
        union mpls_shim top_shim, bossh;
 #endif
 
-       if (m->m_len < sizeof(union mpls_shim) &&
-           (m = m_pullup(m, sizeof(union mpls_shim))) == NULL)
+       if (__predict_false(m->m_len < sizeof(union mpls_shim) &&
+           (m = m_pullup(m, sizeof(union mpls_shim))) == NULL))
                return NULL;
        mshim = mtod(m, union mpls_shim *);
        mshim->s_addr = ntohl(mshim->s_addr);