Commit 7198f8ce authored by Thomas Graf's avatar Thomas Graf Committed by David S. Miller
Browse files

[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: default avatarThomas Graf <tgraf@suug.ch>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 680a27a2

net/ipv6/addrconf.c

+25 −20
Original line number Diff line number Diff line
@@ -2908,24 +2908,14 @@ inet6_rtm_deladdr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) 
	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 @@ inet6_addr_modify(int ifindex, struct in6_addr *pfx, 
	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 @@ inet6_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) 
	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;
@@ -2983,17 +2974,31 @@ inet6_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) 
		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);

	}



	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,

			  u8 scope, int ifindex)

{

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