Date: Sat, 10 Nov 2001 07:11:26 +0300 (MSK) From: .@babolo.ru To: FreeBSD-gnats-submit@freebsd.org Subject: kern/31891: Change mask of loopback net breaks compatibility with older versions Message-ID: <200111100411.HAA12504@aaz.links.ru>
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>Number: 31891
>Category: kern
>Synopsis: Change mask of loopback net breaks compatibility with older versions
>Confidential: no
>Severity: serious
>Priority: low
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Fri Nov 09 20:10:02 PST 2001
>Closed-Date:
>Last-Modified:
>Originator: Aleksandr A. Babaylov
>Release: FreeBSD 4.4
>Organization:
home
>Environment:
FreeBSD cicuta.babolo.ru 4.4-STABLE FreeBSD 4.4-STABLE #0: Sat Oct 6 21:36:53 MSD 2001 babolo@cicuta.babolo.ru:/tmp/babolo/usr/src/sys/cicuta i386
>Description:
There was 4.2 RELEASE, where packets with 127.0.0.0/24 source address
droped on input interfaces. Now it changed to 127.0.0.0/8,
which is incombatible with old configuration.
This net - 127.0.0.0/8 is extremly useful
as private net in clustering environment,
so I propose configuration variable MYLOOP_MASKLEN,
with default meaning that conforms RFC1122
>How-To-Repeat:
Try P2P addresses in 127.0.0.0/8 net.
>Fix:
--- sys/netinet/myloop_masklen.h Sun Aug 26 04:51:23 2001
+++ sys/netinet/myloop_masklen.h Sun Aug 26 04:51:14 2001
@@ -0,0 +1,7 @@
+#include "opt_myloop_masklen.h"
+
+#ifndef MYLOOP_MASKLEN
+#define IN_MY_LOOP(i) (((u_int32_t)(i) & IN_CLASSA_NET) == (IN_LOOPBACKNET << IN_CLASSA_NSHIFT))
+#else
+#define IN_MY_LOOP(i) (((u_int32_t)(i) & (INADDR_BROADCAST << (32 - MYLOOP_MASKLEN))) == (IN_LOOPBACKNET << IN_CLASSA_NSHIFT))
+#endif
--- sys/netinet/in.c Mon Aug 13 20:26:17 2001
+++ sys/netinet/in.c Sun Aug 26 04:52:53 2001
@@ -48,6 +48,7 @@
#include <net/route.h>
#include <netinet/in.h>
+#include <netinet/myloop_masklen.h>
#include <netinet/in_var.h>
#include <netinet/in_pcb.h>
@@ -112,11 +113,11 @@
register u_long i = ntohl(in.s_addr);
register u_long net;
- if (IN_EXPERIMENTAL(i) || IN_MULTICAST(i))
+ if (IN_EXPERIMENTAL(i) || IN_MULTICAST(i) || IN_MY_LOOP(i))
return (0);
if (IN_CLASSA(i)) {
net = i & IN_CLASSA_NET;
- if (net == 0 || net == (IN_LOOPBACKNET << IN_CLASSA_NSHIFT))
+ if (net == 0)
return (0);
}
return (1);
--- sys/netinet/ip_icmp.c Tue Jul 3 15:01:46 2001
+++ sys/netinet/ip_icmp.c Sun Aug 26 04:53:46 2001
@@ -50,6 +50,7 @@
#define _IP_VHL
#include <netinet/in.h>
+#include <netinet/myloop_masklen.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
@@ -612,8 +613,7 @@
int optlen = (IP_VHL_HL(ip->ip_vhl) << 2) - sizeof(struct ip);
if (!in_canforward(ip->ip_src) &&
- ((ntohl(ip->ip_src.s_addr) & IN_CLASSA_NET) !=
- (IN_LOOPBACKNET << IN_CLASSA_NSHIFT))) {
+ !IN_MY_LOOP(ntohl(ip->ip_src.s_addr))) {
m_freem(m); /* Bad return address */
goto done; /* Ip_output() will check for broadcast */
}
--- sys/netinet/ip_input.c Thu Jul 19 10:37:26 2001
+++ sys/netinet/ip_input.c Sun Aug 26 04:54:13 2001
@@ -65,6 +65,7 @@
#include <net/intrq.h>
#include <netinet/in.h>
+#include <netinet/myloop_masklen.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
@@ -347,8 +348,9 @@
}
/* 127/8 must not appear on wire - RFC1122 */
- if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
- (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
+ /* Local change: 127/MYLOOP_MASKLEN */
+ if (IN_MY_LOOP(ntohl(ip->ip_dst.s_addr)) ||
+ IN_MY_LOOP(ntohl(ip->ip_src.s_addr))) {
if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) {
ipstat.ips_badaddr++;
goto bad;
--- sys/i386/conf/LINT Wed Aug 15 05:23:49 2001
+++ sys/i386/conf/LINT Sun Aug 26 02:02:45 2001
@@ -425,6 +425,11 @@
# mchain library. It can be either loaded as KLD or compiled into kernel
options LIBMCHAIN #mbuf management library
+# Usually kernel must to drop any external packet with src in 127/8
+# But it is useful in clusters narrow this mask in kernel to use
+# some nets in 127/8 for kernels interoperate in cluster.
+options MYLOOP_MASKLEN=8
+
# netgraph(4). Enable the base netgraph code with the NETGRAPH option.
# Individual node types can be enabled with the corresponding option
# listed below; however, this is not strictly necessary as netgraph
--- sys/conf/options Fri Aug 3 04:47:27 2001
+++ sys/conf/options Sun Aug 26 02:09:29 2001
@@ -272,6 +272,8 @@
TCPDEBUG
TCP_DROP_SYNFIN opt_tcp_input.h
XBONEHACK
+# For interconnect beetween kernels in cluster
+MYLOOP_MASKLEN
# Netgraph(4). Use option NETGRAPH to enable the base netgraph code.
# Each netgraph node type can be either be compiled into the kernel
>Release-Note:
>Audit-Trail:
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