UPSTREAM: net/ipv6: allow sysctl to change link-local address generation mode
The address generation mode for IPv6 link-local can only be configured
by netlink messages. This patch adds the ability to change the address
generation mode via sysctl.
v1 -> v2
Removed the rtnl lock and switch to use RCU lock to iterate through
the netdev list.
v2 -> v3
Removed the addrgenmode variable from the idev structure and use the
systcl storage for the flag.
Simplifed the logic for sysctl handling by removing the supported
for all operation.
Added support for more types of tunnel interfaces for link-local
address generation.
Based the patches from net-next.
v3 -> v4
Removed unnecessary whitespace changes.
Signed-off-by: Felix Jia <felix.jia@alliedtelesis.co.nz>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit d35a00b8e33dab7385f724e713ae71c8be0a49f4)
Bug: 138428295
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: Ia526e6c1de55e51e35b4b83d95749121fee5d0d1
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 6ba6a5d..3f30d3a 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -240,6 +240,7 @@
.use_oif_addrs_only = 0,
.ignore_routes_with_linkdown = 0,
.keep_addr_on_down = 0,
+ .addr_gen_mode = IN6_ADDR_GEN_MODE_EUI64,
};
static struct ipv6_devconf ipv6_devconf_dflt __read_mostly = {
@@ -288,6 +289,7 @@
.use_oif_addrs_only = 0,
.ignore_routes_with_linkdown = 0,
.keep_addr_on_down = 0,
+ .addr_gen_mode = IN6_ADDR_GEN_MODE_EUI64,
};
/* Check if link is ready: is it up and is a valid qdisc available */
@@ -380,9 +382,9 @@
memcpy(&ndev->cnf, dev_net(dev)->ipv6.devconf_dflt, sizeof(ndev->cnf));
if (ndev->cnf.stable_secret.initialized)
- ndev->addr_gen_mode = IN6_ADDR_GEN_MODE_STABLE_PRIVACY;
+ ndev->cnf.addr_gen_mode = IN6_ADDR_GEN_MODE_STABLE_PRIVACY;
else
- ndev->addr_gen_mode = IN6_ADDR_GEN_MODE_EUI64;
+ ndev->cnf.addr_gen_mode = ipv6_devconf_dflt.addr_gen_mode;
ndev->cnf.mtu6 = dev->mtu;
ndev->nd_parms = neigh_parms_alloc(dev, &nd_tbl);
@@ -2410,8 +2412,8 @@
static bool is_addr_mode_generate_stable(struct inet6_dev *idev)
{
- return idev->addr_gen_mode == IN6_ADDR_GEN_MODE_STABLE_PRIVACY ||
- idev->addr_gen_mode == IN6_ADDR_GEN_MODE_RANDOM;
+ return idev->cnf.addr_gen_mode == IN6_ADDR_GEN_MODE_STABLE_PRIVACY ||
+ idev->cnf.addr_gen_mode == IN6_ADDR_GEN_MODE_RANDOM;
}
int addrconf_prefix_rcv_add_addr(struct net *net, struct net_device *dev,
@@ -3175,7 +3177,7 @@
ipv6_addr_set(&addr, htonl(0xFE800000), 0, 0, 0);
- switch (idev->addr_gen_mode) {
+ switch (idev->cnf.addr_gen_mode) {
case IN6_ADDR_GEN_MODE_RANDOM:
ipv6_gen_mode_random_init(idev);
/* fallthrough */
@@ -3227,8 +3229,8 @@
/* this device type has no EUI support */
if (dev->type == ARPHRD_NONE &&
- idev->addr_gen_mode == IN6_ADDR_GEN_MODE_EUI64)
- idev->addr_gen_mode = IN6_ADDR_GEN_MODE_RANDOM;
+ idev->cnf.addr_gen_mode == IN6_ADDR_GEN_MODE_EUI64)
+ idev->cnf.addr_gen_mode = IN6_ADDR_GEN_MODE_RANDOM;
addrconf_addr_gen(idev, false);
}
@@ -5014,6 +5016,7 @@
array[DEVCONF_DROP_UNICAST_IN_L2_MULTICAST] = cnf->drop_unicast_in_l2_multicast;
array[DEVCONF_DROP_UNSOLICITED_NA] = cnf->drop_unsolicited_na;
array[DEVCONF_KEEP_ADDR_ON_DOWN] = cnf->keep_addr_on_down;
+ array[DEVCONF_ADDR_GEN_MODE] = cnf->addr_gen_mode;
}
static inline size_t inet6_ifla6_size(void)
@@ -5125,7 +5128,7 @@
if (!nla)
goto nla_put_failure;
- if (nla_put_u8(skb, IFLA_INET6_ADDR_GEN_MODE, idev->addr_gen_mode))
+ if (nla_put_u8(skb, IFLA_INET6_ADDR_GEN_MODE, idev->cnf.addr_gen_mode))
goto nla_put_failure;
read_lock_bh(&idev->lock);
@@ -5243,6 +5246,26 @@
return nla_parse_nested(tb, IFLA_INET6_MAX, nla, inet6_af_policy);
}
+static int check_addr_gen_mode(int mode)
+{
+ if (mode != IN6_ADDR_GEN_MODE_EUI64 &&
+ mode != IN6_ADDR_GEN_MODE_NONE &&
+ mode != IN6_ADDR_GEN_MODE_STABLE_PRIVACY &&
+ mode != IN6_ADDR_GEN_MODE_RANDOM)
+ return -EINVAL;
+ return 1;
+}
+
+static int check_stable_privacy(struct inet6_dev *idev, struct net *net,
+ int mode)
+{
+ if (mode == IN6_ADDR_GEN_MODE_STABLE_PRIVACY &&
+ !idev->cnf.stable_secret.initialized &&
+ !net->ipv6.devconf_dflt->stable_secret.initialized)
+ return -EINVAL;
+ return 1;
+}
+
static int inet6_set_link_af(struct net_device *dev, const struct nlattr *nla)
{
int err = -EINVAL;
@@ -5264,18 +5287,11 @@
if (tb[IFLA_INET6_ADDR_GEN_MODE]) {
u8 mode = nla_get_u8(tb[IFLA_INET6_ADDR_GEN_MODE]);
- if (mode != IN6_ADDR_GEN_MODE_EUI64 &&
- mode != IN6_ADDR_GEN_MODE_NONE &&
- mode != IN6_ADDR_GEN_MODE_STABLE_PRIVACY &&
- mode != IN6_ADDR_GEN_MODE_RANDOM)
+ if (check_addr_gen_mode(mode) < 0 ||
+ check_stable_privacy(idev, dev_net(dev), mode) < 0)
return -EINVAL;
- if (mode == IN6_ADDR_GEN_MODE_STABLE_PRIVACY &&
- !idev->cnf.stable_secret.initialized &&
- !dev_net(dev)->ipv6.devconf_dflt->stable_secret.initialized)
- return -EINVAL;
-
- idev->addr_gen_mode = mode;
+ idev->cnf.addr_gen_mode = mode;
err = 0;
}
@@ -5682,6 +5698,47 @@
return ret;
}
+static int addrconf_sysctl_addr_gen_mode(struct ctl_table *ctl, int write,
+ void __user *buffer, size_t *lenp,
+ loff_t *ppos)
+{
+ int ret = 0;
+ int new_val;
+ struct inet6_dev *idev = (struct inet6_dev *)ctl->extra1;
+ struct net *net = (struct net *)ctl->extra2;
+
+ ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
+
+ if (write) {
+ new_val = *((int *)ctl->data);
+
+ if (check_addr_gen_mode(new_val) < 0)
+ return -EINVAL;
+
+ /* request for default */
+ if (&net->ipv6.devconf_dflt->addr_gen_mode == ctl->data) {
+ ipv6_devconf_dflt.addr_gen_mode = new_val;
+
+ /* request for individual net device */
+ } else {
+ if (!idev)
+ return ret;
+
+ if (check_stable_privacy(idev, net, new_val) < 0)
+ return -EINVAL;
+
+ if (idev->cnf.addr_gen_mode != new_val) {
+ idev->cnf.addr_gen_mode = new_val;
+ rtnl_lock();
+ addrconf_dev_config(idev->dev);
+ rtnl_unlock();
+ }
+ }
+ }
+
+ return ret;
+}
+
static int addrconf_sysctl_stable_secret(struct ctl_table *ctl, int write,
void __user *buffer, size_t *lenp,
loff_t *ppos)
@@ -5732,14 +5789,14 @@
struct inet6_dev *idev = __in6_dev_get(dev);
if (idev) {
- idev->addr_gen_mode =
+ idev->cnf.addr_gen_mode =
IN6_ADDR_GEN_MODE_STABLE_PRIVACY;
}
}
} else {
struct inet6_dev *idev = ctl->extra1;
- idev->addr_gen_mode = IN6_ADDR_GEN_MODE_STABLE_PRIVACY;
+ idev->cnf.addr_gen_mode = IN6_ADDR_GEN_MODE_STABLE_PRIVACY;
}
out:
@@ -6115,7 +6172,13 @@
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec,
-
+ },
+ {
+ .procname = "addr_gen_mode",
+ .data = &ipv6_devconf.addr_gen_mode,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = addrconf_sysctl_addr_gen_mode,
},
{
/* sentinel */