ipv6: sysctl to restrict candidate source addresses

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 <ek@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

[Simplified back-port of net-next 3985e8a3611a93bb36789f65db862e5700aab65e]

Bug: 19470192
Bug: 21832279
Bug: 22464419
Change-Id: Icd96382f814a6f3ea53f05beb98c266b1929c5a3
This commit is contained in:
Erik Kline 2015-07-22 16:38:25 +09:00 committed by Lorenzo Colitti
parent edee5ca0b9
commit ab98584aef
3 changed files with 27 additions and 1 deletions

View File

@ -1199,6 +1199,13 @@ router_solicitations - INTEGER
routers are present.
Default: 3
use_oif_addrs_only - 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

View File

@ -174,6 +174,7 @@ struct ipv6_devconf {
__s32 disable_ipv6;
__s32 accept_dad;
__s32 force_tllao;
__s32 use_oif_addrs_only;
void *sysctl;
};
@ -217,6 +218,7 @@ enum {
DEVCONF_FORCE_TLLAO,
DEVCONF_ACCEPT_RA_RT_TABLE,
DEVCONF_USE_OPTIMISTIC,
DEVCONF_USE_OIF_ADDRS_ONLY,
DEVCONF_MAX
};

View File

@ -198,6 +198,7 @@ static struct ipv6_devconf ipv6_devconf __read_mostly = {
.accept_source_route = 0, /* we do not accept RH0 by default. */
.disable_ipv6 = 0,
.accept_dad = 1,
.use_oif_addrs_only = 0,
};
static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = {
@ -233,6 +234,7 @@ static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = {
.accept_source_route = 0, /* we do not accept RH0 by default. */
.disable_ipv6 = 0,
.accept_dad = 1,
.use_oif_addrs_only = 0,
};
/* IPv6 Wildcard Address and Loopback Address defined by RFC2553 */
@ -1166,9 +1168,15 @@ int ipv6_dev_get_saddr(struct net *net, 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)
*/
idev = dst_dev ? __in6_dev_get(dst_dev) : NULL;
if (((dst_type & IPV6_ADDR_MULTICAST) ||
dst.scope <= IPV6_ADDR_SCOPE_LINKLOCAL) &&
dst.scope <= IPV6_ADDR_SCOPE_LINKLOCAL ||
(idev && idev->cnf.use_oif_addrs_only)) &&
dst.ifindex && dev->ifindex != dst.ifindex)
continue;
@ -3992,6 +4000,7 @@ static inline void ipv6_store_devconf(struct ipv6_devconf *cnf,
array[DEVCONF_DISABLE_IPV6] = cnf->disable_ipv6;
array[DEVCONF_ACCEPT_DAD] = cnf->accept_dad;
array[DEVCONF_FORCE_TLLAO] = cnf->force_tllao;
array[DEVCONF_USE_OIF_ADDRS_ONLY] = cnf->use_oif_addrs_only;
}
static inline size_t inet6_ifla6_size(void)
@ -4677,6 +4686,14 @@ static struct addrconf_sysctl_table
.mode = 0644,
.proc_handler = proc_dointvec
},
{
.procname = "use_oif_addrs_only",
.data = &ipv6_devconf.use_oif_addrs_only,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{
/* sentinel */
}