[src/trunk]: src/sys/netmpls * correct packet size

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

details:   https://anonhg.NetBSD.org/src/rev/f8cac0ff4c17
branches:  trunk
changeset: 756009:f8cac0ff4c17
user:      kefren <kefren%NetBSD.org@localhost>
date:      Fri Jul 02 12:25:54 2010 +0000

description:
* correct packet size
* fix crash when cluster was involved
* extension offset is constant
* fix endianess issues in BoS loop
* free cluster if INET not defined but icmp_respond sysctl != 1

diffstat:

 sys/netmpls/mpls_ttl.c |  58 +++++++++++++++++++++++++------------------------
 1 files changed, 30 insertions(+), 28 deletions(-)

diffs (142 lines):

diff -r bd59f74f0919 -r f8cac0ff4c17 sys/netmpls/mpls_ttl.c
--- a/sys/netmpls/mpls_ttl.c    Fri Jul 02 12:13:11 2010 +0000
+++ b/sys/netmpls/mpls_ttl.c    Fri Jul 02 12:25:54 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: mpls_ttl.c,v 1.1 2010/06/26 14:24:29 kefren Exp $ */
+/*     $NetBSD: mpls_ttl.c,v 1.2 2010/07/02 12:25:54 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 1.1 2010/06/26 14:24:29 kefren Exp $");
+__KERNEL_RCSID(0, "$NetBSD: mpls_ttl.c,v 1.2 2010/07/02 12:25:54 kefren Exp $");
 
 #include "opt_inet.h"
 #include "opt_mpls.h"
@@ -131,9 +131,8 @@
 /* ICMP Extensions */
 
 #define ICMP_EXT_VERSION 2
-#define ICMP_EXT_OFFSET        (ICMP_MINLEN + 128)     /* 128 bytes from original
-                                                * datagram required */
-#define MPLS_ICMP_LEN  (ICMP_EXT_OFFSET + sizeof(struct mpls_extension))
+#define        MPLS_RETURN_DATA 128
+#define        ICMP_EXT_OFFSET 128
 
 struct icmp_ext_cmn_hdr {
 #if BYTE_ORDER == BIG_ENDIAN
@@ -172,12 +171,11 @@
 mpls_icmp_error(struct mbuf *n, int type, int code, n_long dest,
     int destmtu, union mpls_shim *shim)
 {
-        struct ip *oip = mtod(n, struct ip *), *nip;
-        unsigned oiplen = oip->ip_hl << 2;
-        struct icmp *icp;
-        struct mbuf *m;
-        unsigned icmplen, mblen;
-
+       struct ip *oip = mtod(n, struct ip *), *nip;
+       unsigned oiplen = oip->ip_hl << 2;
+       struct icmp *icp;
+       struct mbuf *m;
+       unsigned icmplen, mblen, packetlen;
        struct mpls_extension mpls_icmp_ext;
        
        memset(&mpls_icmp_ext, 0, sizeof(mpls_icmp_ext));
@@ -238,6 +236,8 @@
                mblen += m->m_len;
        icmplen = min(mblen, icmplen);
 
+       packetlen = sizeof(struct ip) + ICMP_EXT_OFFSET + sizeof(mpls_icmp_ext);
+
        /*
         * As we are not required to return everything we have,
         * we return whatever we can return at ease.
@@ -247,15 +247,10 @@
         * icmp_sysctl will keep things below that limit.
         */
 
-       /* XXX: should we leave this here ? MCLBYTES should be > 200 anyway
-        * XXX: but it's arch dependant after all and let's keep
-        * XXX: surprises out
-        */
-       KASSERT (MPLS_ICMP_LEN + ICMP_MINLEN <= MCLBYTES);
+       KASSERT (packetlen <= MCLBYTES);
 
        m = m_gethdr(M_DONTWAIT, MT_HEADER);
-       /* XXX: MPLS_ICMP_LEN + ICMP_MINLEN should be always > MHLEN but ... */
-       if (m && (MPLS_ICMP_LEN + ICMP_MINLEN > MHLEN)) {
+       if (m && (packetlen > MHLEN)) {
                MCLGET(m, M_DONTWAIT);
                if ((m->m_flags & M_EXT) == 0) {
                        m_freem(m);
@@ -265,9 +260,13 @@
        if (m == NULL)
                goto freeit;
        MCLAIM(m, n->m_owner);
-       m->m_len = MPLS_ICMP_LEN;
+       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);
+       }
        icp = mtod(m, struct icmp *);
        if ((u_int)type > ICMP_MAXTYPE)
                panic("icmp error");
@@ -290,20 +289,21 @@
        }
 
        icp->icmp_code = code;
-       
-       /* Zero padding in case icmplen < ICMP_EXT_OFFSET */
-       memset(&icp->icmp_ip, 0, MPLS_ICMP_LEN);
+
+       memset(&icp->icmp_ip, 0, ICMP_EXT_OFFSET);
        m_copydata(n, 0, icmplen, (char *)&icp->icmp_ip);
 
-       /* Copy the extension structures */
-       memcpy(((char*)&icp->icmp_ip) + ICMP_EXT_OFFSET - ICMP_MINLEN,
+       /* Append the extension structure */
+       memcpy(((char*)&icp->icmp_ip) + ICMP_EXT_OFFSET,
            &mpls_icmp_ext, sizeof(mpls_icmp_ext));
 
        /*
         * Now, copy old ip header (without options)
         * in front of icmp message.
        */
-       KASSERT(m->m_data - sizeof(struct ip) >= m->m_pktdat);
+       if ((m->m_flags & M_EXT) == 0 &&
+           m->m_data - sizeof(struct ip) < m->m_pktdat)
+               panic("icmp len");
        m->m_data -= sizeof(struct ip);
        m->m_len += sizeof(struct ip);
        m->m_pkthdr.len = m->m_len;
@@ -351,11 +351,11 @@
 
 #ifdef INET
                /*
-                * shim ttl exceed 
+                * shim ttl exceeded
                 * send back ICMP type 11 code 0
                 */
-               bossh.s_addr = top_shim.s_addr =
-                       ntohl(mtod(m, union mpls_shim *)->s_addr);
+               bossh.s_addr = mshim->s_addr;
+               top_shim.s_addr = htonl(mshim->s_addr);
                m_adj(m, sizeof(union mpls_shim));
 
                /* Goto BOS */
@@ -371,6 +371,8 @@
 
                mpls_icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS,
                    0, 0, &top_shim);
+#else
+               m_freem(m);
 #endif
                return NULL;
        }