Per RFC 6724, section 4, "Candidate Source Addresses":
It is RECOMMENDED that the candidate source addresses be the set
of unicast addresses assigned to the interface that will be used
to send to the destination (the "outgoing" interface).
Add a sysctl to enable this behaviour.
Signed-off-by: Erik Kline <e...@google.com>
---
Documentation/networking/ip-sysctl.txt | 7 +++++++
include/linux/ipv6.h | 1 +
include/uapi/linux/ipv6.h | 1 +
net/ipv6/addrconf.c | 22 +++++++++++++++++++---
4 files changed, 28 insertions(+), 3 deletions(-)
diff --git a/Documentation/networking/ip-sysctl.txt
b/Documentation/networking/ip-sysctl.txt
index f63aeef..27007c5 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -1460,6 +1460,13 @@ router_solicitations - INTEGER
routers are present.
Default: 3
+use_oif_addr - BOOLEAN
+ When enabled, the candidate source addresses for destinations
+ routed via this interface are restricted to the set of addresses
+ configured on this interface (vis. RFC 6724, section 4).
+
+ Default: false
+
use_tempaddr - INTEGER
Preference for Privacy Extensions (RFC3041).
<= 0 : disable Privacy Extensions
diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h
index 1319a6b..190b22b 100644
--- a/include/linux/ipv6.h
+++ b/include/linux/ipv6.h
@@ -57,6 +57,7 @@ struct ipv6_devconf {
bool initialized;
struct in6_addr secret;
} stable_secret;
+ __s32 use_oif_addr;
void *sysctl;
};
diff --git a/include/uapi/linux/ipv6.h b/include/uapi/linux/ipv6.h
index 5efa54a..cf9d65a 100644
--- a/include/uapi/linux/ipv6.h
+++ b/include/uapi/linux/ipv6.h
@@ -171,6 +171,7 @@ enum {
DEVCONF_USE_OPTIMISTIC,
DEVCONF_ACCEPT_RA_MTU,
DEVCONF_STABLE_SECRET,
+ DEVCONF_USE_OIF_ADDR,
DEVCONF_MAX
};
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 4c9a024..a7c49bb 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -211,7 +211,8 @@ static struct ipv6_devconf ipv6_devconf __read_mostly = {
.accept_ra_mtu = 1,
.stable_secret = {
.initialized = false,
- }
+ },
+ .use_oif_addr = 0,
};
static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = {
@@ -253,6 +254,7 @@ static struct ipv6_devconf ipv6_devconf_dflt __read_mostly
= {
.stable_secret = {
.initialized = false,
},
+ .use_oif_addr = 0,
};
/* Check if a valid qdisc is available */
@@ -1474,11 +1476,16 @@ int ipv6_dev_get_saddr(struct net *net, const struct
net_device *dst_dev,
* include addresses assigned to interfaces
* belonging to the same site as the outgoing
* interface.)
+ * - "It is RECOMMENDED that the candidate source addresses
+ * be the set of unicast addresses assigned to the
+ * interface that will be used to send to the destination
+ * (the 'outgoing' interface)." (RFC 6724)
*/
if (dst_dev) {
+ idev = __in6_dev_get(dst_dev);
if ((dst_type & IPV6_ADDR_MULTICAST) ||
- dst.scope <= IPV6_ADDR_SCOPE_LINKLOCAL) {
- idev = __in6_dev_get(dst_dev);
+ dst.scope <= IPV6_ADDR_SCOPE_LINKLOCAL ||
+ (idev && idev->cnf.use_oif_addr)) {
use_oif_addr = true;
}
}
@@ -4609,6 +4616,7 @@ static inline void ipv6_store_devconf(struct ipv6_devconf
*cnf,
array[DEVCONF_ACCEPT_RA_FROM_LOCAL] = cnf->accept_ra_from_local;
array[DEVCONF_ACCEPT_RA_MTU] = cnf->accept_ra_mtu;
/* we omit DEVCONF_STABLE_SECRET for now */
+ array[DEVCONF_USE_OIF_ADDR] = cnf->use_oif_addr;
}
static inline size_t inet6_ifla6_size(void)
@@ -5608,6 +5616,14 @@ static struct addrconf_sysctl_table
.proc_handler = addrconf_sysctl_stable_secret,
},
{
+ .procname = "use_oif_addr",
+ .data = &ipv6_devconf.use_oif_addr,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec,
+
+ },
+ {
/* sentinel */
}
},
--
2.4.3.573.g4eafbef
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