From: Jamal Hadi Salim <hadi@cyberus.ca>
Date: Sat, 26 Dec 2009 01:30:22 +0000 (-0800)
Subject: net: restore ip source validation
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=28f6aeea3f12d37bd258b2c0d5ba891bff4ec479;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git

net: restore ip source validation

when using policy routing and the skb mark:
there are cases where a back path validation requires us
to use a different routing table for src ip validation than
the one used for mapping ingress dst ip.
One such a case is transparent proxying where we pretend to be
the destination system and therefore the local table
is used for incoming packets but possibly a main table would
be used on outbound.
Make the default behavior to allow the above and if users
need to turn on the symmetry via sysctl src_valid_mark

Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/include/linux/inetdevice.h b/include/linux/inetdevice.h
index 699e85c01a4d..b2304929434e 100644
--- a/include/linux/inetdevice.h
+++ b/include/linux/inetdevice.h
@@ -81,6 +81,7 @@ static inline void ipv4_devconf_setall(struct in_device *in_dev)
 #define IN_DEV_FORWARD(in_dev)		IN_DEV_CONF_GET((in_dev), FORWARDING)
 #define IN_DEV_MFORWARD(in_dev)		IN_DEV_ANDCONF((in_dev), MC_FORWARDING)
 #define IN_DEV_RPFILTER(in_dev)		IN_DEV_MAXCONF((in_dev), RP_FILTER)
+#define IN_DEV_SRC_VMARK(in_dev)    	IN_DEV_ORCONF((in_dev), SRC_VMARK)
 #define IN_DEV_SOURCE_ROUTE(in_dev)	IN_DEV_ANDCONF((in_dev), \
 						       ACCEPT_SOURCE_ROUTE)
 #define IN_DEV_ACCEPT_LOCAL(in_dev)	IN_DEV_ORCONF((in_dev), ACCEPT_LOCAL)
diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 877ba039e6a4..bd27fbc9db62 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -482,6 +482,7 @@ enum
 	NET_IPV4_CONF_ARP_ACCEPT=21,
 	NET_IPV4_CONF_ARP_NOTIFY=22,
 	NET_IPV4_CONF_ACCEPT_LOCAL=23,
+	NET_IPV4_CONF_SRC_VMARK=24,
 	__NET_IPV4_CONF_MAX
 };
 
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 5cdbc102a418..040c4f05b653 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -1397,6 +1397,7 @@ static struct devinet_sysctl_table {
 		DEVINET_SYSCTL_RW_ENTRY(ACCEPT_SOURCE_ROUTE,
 					"accept_source_route"),
 		DEVINET_SYSCTL_RW_ENTRY(ACCEPT_LOCAL, "accept_local"),
+		DEVINET_SYSCTL_RW_ENTRY(SRC_VMARK, "src_valid_mark"),
 		DEVINET_SYSCTL_RW_ENTRY(PROXY_ARP, "proxy_arp"),
 		DEVINET_SYSCTL_RW_ENTRY(MEDIUM_ID, "medium_id"),
 		DEVINET_SYSCTL_RW_ENTRY(BOOTP_RELAY, "bootp_relay"),
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index 3323168ee52d..82dbf711d6d0 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -252,6 +252,8 @@ int fib_validate_source(__be32 src, __be32 dst, u8 tos, int oif,
 		no_addr = in_dev->ifa_list == NULL;
 		rpf = IN_DEV_RPFILTER(in_dev);
 		accept_local = IN_DEV_ACCEPT_LOCAL(in_dev);
+		if (mark && !IN_DEV_SRC_VMARK(in_dev))
+			fl.mark = 0;
 	}
 	rcu_read_unlock();