1 files changed, 576 insertions, 0 deletions

diff --git a/net/ipv6/addrlabel.c b/net/ipv6/addrlabel.c
new file mode 100644
index 000000000..c7dc8b2de
--- /dev/null
+++ b/net/ipv6/addrlabel.c
@@ -0,0 +1,576 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * IPv6 Address Label subsystem
+ * for the IPv6 "Default" Source Address Selection
+ *
+ * Copyright (C)2007 USAGI/WIDE Project
+ */
+/*
+ * Author:
+ *	YOSHIFUJI Hideaki @ USAGI/WIDE Project <yoshfuji@linux-ipv6.org>
+ */
+
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/rcupdate.h>
+#include <linux/in6.h>
+#include <linux/slab.h>
+#include <net/addrconf.h>
+#include <linux/if_addrlabel.h>
+#include <linux/netlink.h>
+#include <linux/rtnetlink.h>
+
+#if 0
+#define ADDRLABEL(x...) printk(x)
+#else
+#define ADDRLABEL(x...) do { ; } while (0)
+#endif
+
+/*
+ * Policy Table
+ */
+struct ip6addrlbl_entry {
+	struct in6_addr prefix;
+	int prefixlen;
+	int ifindex;
+	int addrtype;
+	u32 label;
+	struct hlist_node list;
+	struct rcu_head rcu;
+};
+
+/*
+ * Default policy table (RFC6724 + extensions)
+ *
+ * prefix		addr_type	label
+ * -------------------------------------------------------------------------
+ * ::1/128		LOOPBACK	0
+ * ::/0			N/A		1
+ * 2002::/16		N/A		2
+ * ::/96		COMPATv4	3
+ * ::ffff:0:0/96	V4MAPPED	4
+ * fc00::/7		N/A		5		ULA (RFC 4193)
+ * 2001::/32		N/A		6		Teredo (RFC 4380)
+ * 2001:10::/28		N/A		7		ORCHID (RFC 4843)
+ * fec0::/10		N/A		11		Site-local
+ *							(deprecated by RFC3879)
+ * 3ffe::/16		N/A		12		6bone
+ *
+ * Note: 0xffffffff is used if we do not have any policies.
+ * Note: Labels for ULA and 6to4 are different from labels listed in RFC6724.
+ */
+
+#define IPV6_ADDR_LABEL_DEFAULT	0xffffffffUL
+
+static const __net_initconst struct ip6addrlbl_init_table
+{
+	const struct in6_addr *prefix;
+	int prefixlen;
+	u32 label;
+} ip6addrlbl_init_table[] = {
+	{	/* ::/0 */
+		.prefix = &in6addr_any,
+		.label = 1,
+	}, {	/* fc00::/7 */
+		.prefix = &(struct in6_addr){ { { 0xfc } } } ,
+		.prefixlen = 7,
+		.label = 5,
+	}, {	/* fec0::/10 */
+		.prefix = &(struct in6_addr){ { { 0xfe, 0xc0 } } },
+		.prefixlen = 10,
+		.label = 11,
+	}, {	/* 2002::/16 */
+		.prefix = &(struct in6_addr){ { { 0x20, 0x02 } } },
+		.prefixlen = 16,
+		.label = 2,
+	}, {	/* 3ffe::/16 */
+		.prefix = &(struct in6_addr){ { { 0x3f, 0xfe } } },
+		.prefixlen = 16,
+		.label = 12,
+	}, {	/* 2001::/32 */
+		.prefix = &(struct in6_addr){ { { 0x20, 0x01 } } },
+		.prefixlen = 32,
+		.label = 6,
+	}, {	/* 2001:10::/28 */
+		.prefix = &(struct in6_addr){ { { 0x20, 0x01, 0x00, 0x10 } } },
+		.prefixlen = 28,
+		.label = 7,
+	}, {	/* ::ffff:0:0 */
+		.prefix = &(struct in6_addr){ { { [10] = 0xff, [11] = 0xff } } },
+		.prefixlen = 96,
+		.label = 4,
+	}, {	/* ::/96 */
+		.prefix = &in6addr_any,
+		.prefixlen = 96,
+		.label = 3,
+	}, {	/* ::1/128 */
+		.prefix = &in6addr_loopback,
+		.prefixlen = 128,
+		.label = 0,
+	}
+};
+
+/* Find label */
+static bool __ip6addrlbl_match(const struct ip6addrlbl_entry *p,
+			       const struct in6_addr *addr,
+			       int addrtype, int ifindex)
+{
+	if (p->ifindex && p->ifindex != ifindex)
+		return false;
+	if (p->addrtype && p->addrtype != addrtype)
+		return false;
+	if (!ipv6_prefix_equal(addr, &p->prefix, p->prefixlen))
+		return false;
+	return true;
+}
+
+static struct ip6addrlbl_entry *__ipv6_addr_label(struct net *net,
+						  const struct in6_addr *addr,
+						  int type, int ifindex)
+{
+	struct ip6addrlbl_entry *p;
+
+	hlist_for_each_entry_rcu(p, &net->ipv6.ip6addrlbl_table.head, list) {
+		if (__ip6addrlbl_match(p, addr, type, ifindex))
+			return p;
+	}
+	return NULL;
+}
+
+u32 ipv6_addr_label(struct net *net,
+		    const struct in6_addr *addr, int type, int ifindex)
+{
+	u32 label;
+	struct ip6addrlbl_entry *p;
+
+	type &= IPV6_ADDR_MAPPED | IPV6_ADDR_COMPATv4 | IPV6_ADDR_LOOPBACK;
+
+	rcu_read_lock();
+	p = __ipv6_addr_label(net, addr, type, ifindex);
+	label = p ? p->label : IPV6_ADDR_LABEL_DEFAULT;
+	rcu_read_unlock();
+
+	ADDRLABEL(KERN_DEBUG "%s(addr=%pI6, type=%d, ifindex=%d) => %08x\n",
+		  __func__, addr, type, ifindex, label);
+
+	return label;
+}
+
+/* allocate one entry */
+static struct ip6addrlbl_entry *ip6addrlbl_alloc(const struct in6_addr *prefix,
+						 int prefixlen, int ifindex,
+						 u32 label)
+{
+	struct ip6addrlbl_entry *newp;
+	int addrtype;
+
+	ADDRLABEL(KERN_DEBUG "%s(prefix=%pI6, prefixlen=%d, ifindex=%d, label=%u)\n",
+		  __func__, prefix, prefixlen, ifindex, (unsigned int)label);
+
+	addrtype = ipv6_addr_type(prefix) & (IPV6_ADDR_MAPPED | IPV6_ADDR_COMPATv4 | IPV6_ADDR_LOOPBACK);
+
+	switch (addrtype) {
+	case IPV6_ADDR_MAPPED:
+		if (prefixlen > 96)
+			return ERR_PTR(-EINVAL);
+		if (prefixlen < 96)
+			addrtype = 0;
+		break;
+	case IPV6_ADDR_COMPATv4:
+		if (prefixlen != 96)
+			addrtype = 0;
+		break;
+	case IPV6_ADDR_LOOPBACK:
+		if (prefixlen != 128)
+			addrtype = 0;
+		break;
+	}
+
+	newp = kmalloc(sizeof(*newp), GFP_KERNEL);
+	if (!newp)
+		return ERR_PTR(-ENOMEM);
+
+	ipv6_addr_prefix(&newp->prefix, prefix, prefixlen);
+	newp->prefixlen = prefixlen;
+	newp->ifindex = ifindex;
+	newp->addrtype = addrtype;
+	newp->label = label;
+	INIT_HLIST_NODE(&newp->list);
+	return newp;
+}
+
+/* add a label */
+static int __ip6addrlbl_add(struct net *net, struct ip6addrlbl_entry *newp,
+			    int replace)
+{
+	struct ip6addrlbl_entry *last = NULL, *p = NULL;
+	struct hlist_node *n;
+	int ret = 0;
+
+	ADDRLABEL(KERN_DEBUG "%s(newp=%p, replace=%d)\n", __func__, newp,
+		  replace);
+
+	hlist_for_each_entry_safe(p, n,	&net->ipv6.ip6addrlbl_table.head, list) {
+		if (p->prefixlen == newp->prefixlen &&
+		    p->ifindex == newp->ifindex &&
+		    ipv6_addr_equal(&p->prefix, &newp->prefix)) {
+			if (!replace) {
+				ret = -EEXIST;
+				goto out;
+			}
+			hlist_replace_rcu(&p->list, &newp->list);
+			kfree_rcu(p, rcu);
+			goto out;
+		} else if ((p->prefixlen == newp->prefixlen && !p->ifindex) ||
+			   (p->prefixlen < newp->prefixlen)) {
+			hlist_add_before_rcu(&newp->list, &p->list);
+			goto out;
+		}
+		last = p;
+	}
+	if (last)
+		hlist_add_behind_rcu(&newp->list, &last->list);
+	else
+		hlist_add_head_rcu(&newp->list, &net->ipv6.ip6addrlbl_table.head);
+out:
+	if (!ret)
+		net->ipv6.ip6addrlbl_table.seq++;
+	return ret;
+}
+
+/* add a label */
+static int ip6addrlbl_add(struct net *net,
+			  const struct in6_addr *prefix, int prefixlen,
+			  int ifindex, u32 label, int replace)
+{
+	struct ip6addrlbl_entry *newp;
+	int ret = 0;
+
+	ADDRLABEL(KERN_DEBUG "%s(prefix=%pI6, prefixlen=%d, ifindex=%d, label=%u, replace=%d)\n",
+		  __func__, prefix, prefixlen, ifindex, (unsigned int)label,
+		  replace);
+
+	newp = ip6addrlbl_alloc(prefix, prefixlen, ifindex, label);
+	if (IS_ERR(newp))
+		return PTR_ERR(newp);
+	spin_lock(&net->ipv6.ip6addrlbl_table.lock);
+	ret = __ip6addrlbl_add(net, newp, replace);
+	spin_unlock(&net->ipv6.ip6addrlbl_table.lock);
+	if (ret)
+		kfree(newp);
+	return ret;
+}
+
+/* remove a label */
+static int __ip6addrlbl_del(struct net *net,
+			    const struct in6_addr *prefix, int prefixlen,
+			    int ifindex)
+{
+	struct ip6addrlbl_entry *p = NULL;
+	struct hlist_node *n;
+	int ret = -ESRCH;
+
+	ADDRLABEL(KERN_DEBUG "%s(prefix=%pI6, prefixlen=%d, ifindex=%d)\n",
+		  __func__, prefix, prefixlen, ifindex);
+
+	hlist_for_each_entry_safe(p, n, &net->ipv6.ip6addrlbl_table.head, list) {
+		if (p->prefixlen == prefixlen &&
+		    p->ifindex == ifindex &&
+		    ipv6_addr_equal(&p->prefix, prefix)) {
+			hlist_del_rcu(&p->list);
+			kfree_rcu(p, rcu);
+			ret = 0;
+			break;
+		}
+	}
+	return ret;
+}
+
+static int ip6addrlbl_del(struct net *net,
+			  const struct in6_addr *prefix, int prefixlen,
+			  int ifindex)
+{
+	struct in6_addr prefix_buf;
+	int ret;
+
+	ADDRLABEL(KERN_DEBUG "%s(prefix=%pI6, prefixlen=%d, ifindex=%d)\n",
+		  __func__, prefix, prefixlen, ifindex);
+
+	ipv6_addr_prefix(&prefix_buf, prefix, prefixlen);
+	spin_lock(&net->ipv6.ip6addrlbl_table.lock);
+	ret = __ip6addrlbl_del(net, &prefix_buf, prefixlen, ifindex);
+	spin_unlock(&net->ipv6.ip6addrlbl_table.lock);
+	return ret;
+}
+
+/* add default label */
+static int __net_init ip6addrlbl_net_init(struct net *net)
+{
+	struct ip6addrlbl_entry *p = NULL;
+	struct hlist_node *n;
+	int err;
+	int i;
+
+	ADDRLABEL(KERN_DEBUG "%s\n", __func__);
+
+	spin_lock_init(&net->ipv6.ip6addrlbl_table.lock);
+	INIT_HLIST_HEAD(&net->ipv6.ip6addrlbl_table.head);
+
+	for (i = 0; i < ARRAY_SIZE(ip6addrlbl_init_table); i++) {
+		err = ip6addrlbl_add(net,
+				     ip6addrlbl_init_table[i].prefix,
+				     ip6addrlbl_init_table[i].prefixlen,
+				     0,
+				     ip6addrlbl_init_table[i].label, 0);
+		if (err)
+			goto err_ip6addrlbl_add;
+	}
+	return 0;
+
+err_ip6addrlbl_add:
+	hlist_for_each_entry_safe(p, n, &net->ipv6.ip6addrlbl_table.head, list) {
+		hlist_del_rcu(&p->list);
+		kfree_rcu(p, rcu);
+	}
+	return err;
+}
+
+static void __net_exit ip6addrlbl_net_exit(struct net *net)
+{
+	struct ip6addrlbl_entry *p = NULL;
+	struct hlist_node *n;
+
+	/* Remove all labels belonging to the exiting net */
+	spin_lock(&net->ipv6.ip6addrlbl_table.lock);
+	hlist_for_each_entry_safe(p, n, &net->ipv6.ip6addrlbl_table.head, list) {
+		hlist_del_rcu(&p->list);
+		kfree_rcu(p, rcu);
+	}
+	spin_unlock(&net->ipv6.ip6addrlbl_table.lock);
+}
+
+static struct pernet_operations ipv6_addr_label_ops = {
+	.init = ip6addrlbl_net_init,
+	.exit = ip6addrlbl_net_exit,
+};
+
+int __init ipv6_addr_label_init(void)
+{
+	return register_pernet_subsys(&ipv6_addr_label_ops);
+}
+
+void ipv6_addr_label_cleanup(void)
+{
+	unregister_pernet_subsys(&ipv6_addr_label_ops);
+}
+
+static const struct nla_policy ifal_policy[IFAL_MAX+1] = {
+	[IFAL_ADDRESS]		= { .len = sizeof(struct in6_addr), },
+	[IFAL_LABEL]		= { .len = sizeof(u32), },
+};
+
+static bool addrlbl_ifindex_exists(struct net *net, int ifindex)
+{
+
+	struct net_device *dev;
+
+	rcu_read_lock();
+	dev = dev_get_by_index_rcu(net, ifindex);
+	rcu_read_unlock();
+
+	return dev != NULL;
+}
+
+static int ip6addrlbl_newdel(struct sk_buff *skb, struct nlmsghdr *nlh,
+			     struct netlink_ext_ack *extack)
+{
+	struct net *net = sock_net(skb->sk);
+	struct ifaddrlblmsg *ifal;
+	struct nlattr *tb[IFAL_MAX+1];
+	struct in6_addr *pfx;
+	u32 label;
+	int err = 0;
+
+	err = nlmsg_parse(nlh, sizeof(*ifal), tb, IFAL_MAX, ifal_policy,
+			  extack);
+	if (err < 0)
+		return err;
+
+	ifal = nlmsg_data(nlh);
+
+	if (ifal->ifal_family != AF_INET6 ||
+	    ifal->ifal_prefixlen > 128)
+		return -EINVAL;
+
+	if (!tb[IFAL_ADDRESS])
+		return -EINVAL;
+	pfx = nla_data(tb[IFAL_ADDRESS]);
+
+	if (!tb[IFAL_LABEL])
+		return -EINVAL;
+	label = nla_get_u32(tb[IFAL_LABEL]);
+	if (label == IPV6_ADDR_LABEL_DEFAULT)
+		return -EINVAL;
+
+	switch (nlh->nlmsg_type) {
+	case RTM_NEWADDRLABEL:
+		if (ifal->ifal_index &&
+		    !addrlbl_ifindex_exists(net, ifal->ifal_index))
+			return -EINVAL;
+
+		err = ip6addrlbl_add(net, pfx, ifal->ifal_prefixlen,
+				     ifal->ifal_index, label,
+				     nlh->nlmsg_flags & NLM_F_REPLACE);
+		break;
+	case RTM_DELADDRLABEL:
+		err = ip6addrlbl_del(net, pfx, ifal->ifal_prefixlen,
+				     ifal->ifal_index);
+		break;
+	default:
+		err = -EOPNOTSUPP;
+	}
+	return err;
+}
+
+static void ip6addrlbl_putmsg(struct nlmsghdr *nlh,
+			      int prefixlen, int ifindex, u32 lseq)
+{
+	struct ifaddrlblmsg *ifal = nlmsg_data(nlh);
+	ifal->ifal_family = AF_INET6;
+	ifal->ifal_prefixlen = prefixlen;
+	ifal->ifal_flags = 0;
+	ifal->ifal_index = ifindex;
+	ifal->ifal_seq = lseq;
+};
+
+static int ip6addrlbl_fill(struct sk_buff *skb,
+			   struct ip6addrlbl_entry *p,
+			   u32 lseq,
+			   u32 portid, u32 seq, int event,
+			   unsigned int flags)
+{
+	struct nlmsghdr *nlh = nlmsg_put(skb, portid, seq, event,
+					 sizeof(struct ifaddrlblmsg), flags);
+	if (!nlh)
+		return -EMSGSIZE;
+
+	ip6addrlbl_putmsg(nlh, p->prefixlen, p->ifindex, lseq);
+
+	if (nla_put_in6_addr(skb, IFAL_ADDRESS, &p->prefix) < 0 ||
+	    nla_put_u32(skb, IFAL_LABEL, p->label) < 0) {
+		nlmsg_cancel(skb, nlh);
+		return -EMSGSIZE;
+	}
+
+	nlmsg_end(skb, nlh);
+	return 0;
+}
+
+static int ip6addrlbl_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	struct net *net = sock_net(skb->sk);
+	struct ip6addrlbl_entry *p;
+	int idx = 0, s_idx = cb->args[0];
+	int err;
+
+	rcu_read_lock();
+	hlist_for_each_entry_rcu(p, &net->ipv6.ip6addrlbl_table.head, list) {
+		if (idx >= s_idx) {
+			err = ip6addrlbl_fill(skb, p,
+					      net->ipv6.ip6addrlbl_table.seq,
+					      NETLINK_CB(cb->skb).portid,
+					      cb->nlh->nlmsg_seq,
+					      RTM_NEWADDRLABEL,
+					      NLM_F_MULTI);
+			if (err < 0)
+				break;
+		}
+		idx++;
+	}
+	rcu_read_unlock();
+	cb->args[0] = idx;
+	return skb->len;
+}
+
+static inline int ip6addrlbl_msgsize(void)
+{
+	return NLMSG_ALIGN(sizeof(struct ifaddrlblmsg))
+		+ nla_total_size(16)	/* IFAL_ADDRESS */
+		+ nla_total_size(4);	/* IFAL_LABEL */
+}
+
+static int ip6addrlbl_get(struct sk_buff *in_skb, struct nlmsghdr *nlh,
+			  struct netlink_ext_ack *extack)
+{
+	struct net *net = sock_net(in_skb->sk);
+	struct ifaddrlblmsg *ifal;
+	struct nlattr *tb[IFAL_MAX+1];
+	struct in6_addr *addr;
+	u32 lseq;
+	int err = 0;
+	struct ip6addrlbl_entry *p;
+	struct sk_buff *skb;
+
+	err = nlmsg_parse(nlh, sizeof(*ifal), tb, IFAL_MAX, ifal_policy,
+			  extack);
+	if (err < 0)
+		return err;
+
+	ifal = nlmsg_data(nlh);
+
+	if (ifal->ifal_family != AF_INET6 ||
+	    ifal->ifal_prefixlen != 128)
+		return -EINVAL;
+
+	if (ifal->ifal_index &&
+	    !addrlbl_ifindex_exists(net, ifal->ifal_index))
+		return -EINVAL;
+
+	if (!tb[IFAL_ADDRESS])
+		return -EINVAL;
+	addr = nla_data(tb[IFAL_ADDRESS]);
+
+	skb = nlmsg_new(ip6addrlbl_msgsize(), GFP_KERNEL);
+	if (!skb)
+		return -ENOBUFS;
+
+	err = -ESRCH;
+
+	rcu_read_lock();
+	p = __ipv6_addr_label(net, addr, ipv6_addr_type(addr), ifal->ifal_index);
+	lseq = net->ipv6.ip6addrlbl_table.seq;
+	if (p)
+		err = ip6addrlbl_fill(skb, p, lseq,
+				      NETLINK_CB(in_skb).portid,
+				      nlh->nlmsg_seq,
+				      RTM_NEWADDRLABEL, 0);
+	rcu_read_unlock();
+
+	if (err < 0) {
+		WARN_ON(err == -EMSGSIZE);
+		kfree_skb(skb);
+	} else {
+		err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
+	}
+	return err;
+}
+
+int __init ipv6_addr_label_rtnl_register(void)
+{
+	int ret;
+
+	ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_NEWADDRLABEL,
+				   ip6addrlbl_newdel,
+				   NULL, RTNL_FLAG_DOIT_UNLOCKED);
+	if (ret < 0)
+		return ret;
+	ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_DELADDRLABEL,
+				   ip6addrlbl_newdel,
+				   NULL, RTNL_FLAG_DOIT_UNLOCKED);
+	if (ret < 0)
+		return ret;
+	ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETADDRLABEL,
+				   ip6addrlbl_get,
+				   ip6addrlbl_dump, RTNL_FLAG_DOIT_UNLOCKED);
+	return ret;
+}