[IPV6] address: Support NLM_F_EXCL when adding addresses
iproute2 doesn't provide the NLM_F_CREATE flag when adding addresses,
it is assumed to be implied. The existing code issues a check on
said flag when the modify operation fails (likely due to ENOENT)
before continueing to create it, this leads to a hard to predict
result, therefore the NLM_F_CREATE check is removed.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index bb18b9c..1e5a296 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -2908,24 +2908,14 @@
return inet6_addr_del(ifm->ifa_index, pfx, ifm->ifa_prefixlen);
}
-static int
-inet6_addr_modify(int ifindex, struct in6_addr *pfx,
- __u32 prefered_lft, __u32 valid_lft)
+static int inet6_addr_modify(struct inet6_ifaddr *ifp, u32 prefered_lft,
+ u32 valid_lft)
{
- struct inet6_ifaddr *ifp = NULL;
- struct net_device *dev;
int ifa_flags = 0;
- if ((dev = __dev_get_by_index(ifindex)) == NULL)
- return -ENODEV;
-
if (!valid_lft || (prefered_lft > valid_lft))
return -EINVAL;
- ifp = ipv6_get_ifaddr(pfx, dev, 1);
- if (ifp == NULL)
- return -ENOENT;
-
if (valid_lft == INFINITY_LIFE_TIME)
ifa_flags = IFA_F_PERMANENT;
else if (valid_lft >= 0x7FFFFFFF/HZ)
@@ -2947,7 +2937,6 @@
spin_unlock_bh(&ifp->lock);
if (!(ifp->flags&IFA_F_TENTATIVE))
ipv6_ifa_notify(0, ifp);
- in6_ifa_put(ifp);
addrconf_verify(0);
@@ -2960,6 +2949,8 @@
struct ifaddrmsg *ifm;
struct nlattr *tb[IFA_MAX+1];
struct in6_addr *pfx;
+ struct inet6_ifaddr *ifa;
+ struct net_device *dev;
u32 valid_lft, preferred_lft;
int err;
@@ -2983,15 +2974,29 @@
valid_lft = INFINITY_LIFE_TIME;
}
- if (nlh->nlmsg_flags & NLM_F_REPLACE) {
- err = inet6_addr_modify(ifm->ifa_index, pfx,
- preferred_lft, valid_lft);
- if (err == 0 || !(nlh->nlmsg_flags & NLM_F_CREATE))
- return err;
+ dev = __dev_get_by_index(ifm->ifa_index);
+ if (dev == NULL)
+ return -ENODEV;
+
+ ifa = ipv6_get_ifaddr(pfx, dev, 1);
+ if (ifa == NULL) {
+ /*
+ * It would be best to check for !NLM_F_CREATE here but
+ * userspace alreay relies on not having to provide this.
+ */
+ return inet6_addr_add(ifm->ifa_index, pfx, ifm->ifa_prefixlen,
+ preferred_lft, valid_lft);
}
- return inet6_addr_add(ifm->ifa_index, pfx, ifm->ifa_prefixlen,
- preferred_lft, valid_lft);
+ if (nlh->nlmsg_flags & NLM_F_EXCL ||
+ !(nlh->nlmsg_flags & NLM_F_REPLACE))
+ err = -EEXIST;
+ else
+ err = inet6_addr_modify(ifa, preferred_lft, valid_lft);
+
+ in6_ifa_put(ifa);
+
+ return err;
}
static void put_ifaddrmsg(struct nlmsghdr *nlh, u8 prefixlen, u8 flags,