diff -urN linux-2.4.26-pre5/Documentation/filesystems/proc.txt linux-2.4.26-pre5-sts/Documentation/filesystems/proc.txt
--- linux-2.4.26-pre5/Documentation/filesystems/proc.txt Mon Apr 21 22:40:56 2003
+++ linux-2.4.26-pre5-sts/Documentation/filesystems/proc.txt Sat Mar 20 23:28:36 2004
@@ -1527,6 +1527,15 @@
Log packets with source addresses with no known route to kernel log.
+loop
+----
+
+By default (loop=0) the traffic between local IP addresses
+is routed via interface "lo". Setting this flag for two
+interfaces allows traffic between their IP addresses to
+be looped externally. This is useful for setups where the
+interfaces are attached to same broadcast medium.
+
mc_forwarding
-------------
diff -urN linux-2.4.26-pre5/Documentation/networking/ip-sysctl.txt linux-2.4.26-pre5-sts/Documentation/networking/ip-sysctl.txt
--- linux-2.4.26-pre5/Documentation/networking/ip-sysctl.txt Sat Mar 20 10:08:18 2004
+++ linux-2.4.26-pre5-sts/Documentation/networking/ip-sysctl.txt Sat Mar 20 23:28:36 2004
@@ -391,6 +391,13 @@
conf/all/mc_forwarding must also be set to TRUE to enable multicast routing
for the interface
+loop - BOOLEAN
+ By default (loop=0) the traffic between local IP addresses
+ is routed via interface "lo". Setting this flag for two
+ interfaces allows traffic between their IP addresses to
+ be looped externally. This is useful for setups where the
+ interfaces are attached to same broadcast medium.
+
medium_id - INTEGER
Integer value used to differentiate the devices by the medium they
are attached to. Two devices can have different id values when
diff -urN linux-2.4.26-pre5/include/linux/inetdevice.h linux-2.4.26-pre5-sts/include/linux/inetdevice.h
--- linux-2.4.26-pre5/include/linux/inetdevice.h Sat Mar 20 10:08:20 2004
+++ linux-2.4.26-pre5-sts/include/linux/inetdevice.h Sat Mar 20 23:29:55 2004
@@ -22,6 +22,7 @@
int arp_ignore;
int medium_id;
int force_igmp_version;
+ int loop;
void *sysctl;
};
@@ -73,6 +74,7 @@
#define IN_DEV_ARPFILTER(in_dev) (ipv4_devconf.arp_filter || (in_dev)->cnf.arp_filter)
#define IN_DEV_ARP_ANNOUNCE(in_dev) (max(ipv4_devconf.arp_announce, (in_dev)->cnf.arp_announce))
#define IN_DEV_ARP_IGNORE(in_dev) (max(ipv4_devconf.arp_ignore, (in_dev)->cnf.arp_ignore))
+#define IN_DEV_LOOP(in_dev) ((in_dev)->cnf.loop)
struct in_ifaddr
{
diff -urN linux-2.4.26-pre5/include/linux/sysctl.h linux-2.4.26-pre5-sts/include/linux/sysctl.h
--- linux-2.4.26-pre5/include/linux/sysctl.h Sat Mar 20 10:10:11 2004
+++ linux-2.4.26-pre5-sts/include/linux/sysctl.h Sat Mar 20 23:30:48 2004
@@ -364,6 +364,7 @@
NET_IPV4_CONF_FORCE_IGMP_VERSION=17,
NET_IPV4_CONF_ARP_ANNOUNCE=18,
NET_IPV4_CONF_ARP_IGNORE=19,
+ NET_IPV4_CONF_LOOP=20,
};
/* /proc/sys/net/ipv4/netfilter */
diff -urN linux-2.4.26-pre5/net/ipv4/devinet.c linux-2.4.26-pre5-sts/net/ipv4/devinet.c
--- linux-2.4.26-pre5/net/ipv4/devinet.c Sat Mar 20 10:08:21 2004
+++ linux-2.4.26-pre5-sts/net/ipv4/devinet.c Sat Mar 20 23:32:05 2004
@@ -1134,7 +1134,7 @@
static struct devinet_sysctl_table
{
struct ctl_table_header *sysctl_header;
- ctl_table devinet_vars[20];
+ ctl_table devinet_vars[21];
ctl_table devinet_dev[2];
ctl_table devinet_conf_dir[2];
ctl_table devinet_proto_dir[2];
@@ -1188,6 +1188,9 @@
&proc_dointvec},
{NET_IPV4_CONF_ARP_IGNORE, "arp_ignore",
&ipv4_devconf.arp_ignore, sizeof(int), 0644, NULL,
+ &proc_dointvec},
+ {NET_IPV4_CONF_LOOP, "loop",
+ &ipv4_devconf.loop, sizeof(int), 0644, NULL,
&proc_dointvec},
{NET_IPV4_CONF_FORCE_IGMP_VERSION, "force_igmp_version",
&ipv4_devconf.force_igmp_version, sizeof(int), 0644, NULL,
diff -urN linux-2.4.26-pre5/net/ipv4/fib_frontend.c linux-2.4.26-pre5-sts/net/ipv4/fib_frontend.c
--- linux-2.4.26-pre5/net/ipv4/fib_frontend.c Sat Sep 13 07:57:34 2003
+++ linux-2.4.26-pre5-sts/net/ipv4/fib_frontend.c Sat Mar 20 23:28:36 2004
@@ -209,7 +209,7 @@
struct in_device *in_dev;
struct rt_key key;
struct fib_result res;
- int no_addr, rpf;
+ int no_addr, rpf, loop;
int ret;
key.dst = src;
@@ -219,12 +219,13 @@
key.iif = oif;
key.scope = RT_SCOPE_UNIVERSE;
- no_addr = rpf = 0;
+ no_addr = rpf = loop = 0;
read_lock(&inetdev_lock);
in_dev = __in_dev_get(dev);
if (in_dev) {
no_addr = in_dev->ifa_list == NULL;
rpf = IN_DEV_RPFILTER(in_dev);
+ loop = IN_DEV_LOOP(in_dev);
}
read_unlock(&inetdev_lock);
@@ -233,6 +234,11 @@
if (fib_lookup(&key, &res))
goto last_resort;
+ if (loop && res.type == RTN_LOCAL) {
+ *spec_dst = FIB_RES_PREFSRC(res);
+ fib_res_put(&res);
+ return 0;
+ }
if (res.type != RTN_UNICAST)
goto e_inval_res;
*spec_dst = FIB_RES_PREFSRC(res);
diff -urN linux-2.4.26-pre5/net/ipv4/route.c linux-2.4.26-pre5-sts/net/ipv4/route.c
--- linux-2.4.26-pre5/net/ipv4/route.c Sat Dec 6 08:14:52 2003
+++ linux-2.4.26-pre5-sts/net/ipv4/route.c Sat Mar 20 23:28:36 2004
@@ -1853,6 +1853,11 @@
dev_put(dev_out);
goto out; /* Wrong error code */
}
+ err = -ENETDOWN;
+ if (!(dev_out->flags&IFF_UP)) {
+ dev_put(dev_out);
+ goto out;
+ }
if (LOCAL_MCAST(oldkey->dst) || oldkey->dst == 0xFFFFFFFF) {
if (!key.src)
@@ -1922,10 +1927,41 @@
goto e_inval;
if (res.type == RTN_LOCAL) {
- if (!key.src)
- key.src = key.dst;
+ struct in_device *in_dev;
+ u32 src;
+
if (dev_out)
dev_put(dev_out);
+ dev_out = FIB_RES_DEV(res);
+ in_dev = in_dev_get(dev_out);
+ src = key.src? : FIB_RES_PREFSRC(res);
+ if (in_dev && IN_DEV_LOOP(in_dev) && src) {
+ struct net_device *dev_src;
+
+ in_dev_put(in_dev);
+ in_dev = NULL;
+ dev_src = ip_dev_find(src);
+ if (dev_src && dev_src != dev_out &&
+ (in_dev = in_dev_get(dev_src)) &&
+ IN_DEV_LOOP(in_dev)) {
+ in_dev_put(in_dev);
+ dev_out = dev_src;
+ key.src = src;
+ key.oif = dev_out->ifindex;
+ res.type = RTN_UNICAST;
+ if (res.fi) {
+ fib_info_put(res.fi);
+ res.fi = NULL;
+ }
+ goto make_route;
+ }
+ if (dev_src)
+ dev_put(dev_src);
+ }
+ if (in_dev)
+ in_dev_put(in_dev);
+ if (!key.src)
+ key.src = key.dst;
dev_out = &loopback_dev;
dev_hold(dev_out);
key.oif = dev_out->ifindex;