--- /dev/null
+/*
+ * 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 <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;
+ atomic_t refcnt;
+ struct rcu_head rcu;
+};
+
+static struct ip6addrlbl_table
+{
+ struct hlist_head head;
+ spinlock_t lock;
+ u32 seq;
+} ip6addrlbl_table;
+
+/*
+ * Default policy table (RFC3484 + 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)
+ *
+ * Note: 0xffffffff is used if we do not have any policies.
+ */
+
+#define IPV6_ADDR_LABEL_DEFAULT 0xffffffffUL
+
+static const __initdata 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,
+ },{ /* 2002::/16 */
+ .prefix = &(struct in6_addr){{{ 0x20, 0x02 }}},
+ .prefixlen = 16,
+ .label = 2,
+ },{ /* 2001::/32 */
+ .prefix = &(struct in6_addr){{{ 0x20, 0x01 }}},
+ .prefixlen = 32,
+ .label = 6,
+ },{ /* ::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,
+ }
+};
+
+/* Object management */
+static inline void ip6addrlbl_free(struct ip6addrlbl_entry *p)
+{
+ kfree(p);
+}
+
+static inline int ip6addrlbl_hold(struct ip6addrlbl_entry *p)
+{
+ return atomic_inc_not_zero(&p->refcnt);
+}
+
+static inline void ip6addrlbl_put(struct ip6addrlbl_entry *p)
+{
+ if (atomic_dec_and_test(&p->refcnt))
+ ip6addrlbl_free(p);
+}
+
+static void ip6addrlbl_free_rcu(struct rcu_head *h)
+{
+ ip6addrlbl_free(container_of(h, struct ip6addrlbl_entry, rcu));
+}
+
+/* Find label */
+static int __ip6addrlbl_match(struct ip6addrlbl_entry *p,
+ const struct in6_addr *addr,
+ int addrtype, int ifindex)
+{
+ if (p->ifindex && p->ifindex != ifindex)
+ return 0;
+ if (p->addrtype && p->addrtype != addrtype)
+ return 0;
+ if (!ipv6_prefix_equal(addr, &p->prefix, p->prefixlen))
+ return 0;
+ return 1;
+}
+
+static struct ip6addrlbl_entry *__ipv6_addr_label(const struct in6_addr *addr,
+ int type, int ifindex)
+{
+ struct hlist_node *pos;
+ struct ip6addrlbl_entry *p;
+ hlist_for_each_entry_rcu(p, pos, &ip6addrlbl_table.head, list) {
+ if (__ip6addrlbl_match(p, addr, type, ifindex))
+ return p;
+ }
+ return NULL;
+}
+
+u32 ipv6_addr_label(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(addr, type, ifindex);
+ label = p ? p->label : IPV6_ADDR_LABEL_DEFAULT;
+ rcu_read_unlock();
+
+ ADDRLABEL(KERN_DEBUG "%s(addr=" NIP6_FMT ", type=%d, ifindex=%d) => %08x\n",
+ __FUNCTION__,
+ NIP6(*addr), type, ifindex,
+ label);
+
+ return label;
+}
+
+/* allocate one entry */
+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=" NIP6_FMT ", prefixlen=%d, ifindex=%d, label=%u)\n",
+ __FUNCTION__,
+ NIP6(*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);
+ atomic_set(&newp->refcnt, 1);
+ return newp;
+}
+
+/* add a label */
+int __ip6addrlbl_add(struct ip6addrlbl_entry *newp, int replace)
+{
+ int ret = 0;
+
+ ADDRLABEL(KERN_DEBUG "%s(newp=%p, replace=%d)\n",
+ __FUNCTION__,
+ newp, replace);
+
+ if (hlist_empty(&ip6addrlbl_table.head)) {
+ hlist_add_head_rcu(&newp->list, &ip6addrlbl_table.head);
+ } else {
+ struct hlist_node *pos, *n;
+ struct ip6addrlbl_entry *p = NULL;
+ hlist_for_each_entry_safe(p, pos, n,
+ &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);
+ ip6addrlbl_put(p);
+ call_rcu(&p->rcu, ip6addrlbl_free_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;
+ }
+ }
+ hlist_add_after_rcu(&p->list, &newp->list);
+ }
+out:
+ if (!ret)
+ ip6addrlbl_table.seq++;
+ return ret;
+}
+
+/* add a label */
+int ip6addrlbl_add(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=" NIP6_FMT ", prefixlen=%d, ifindex=%d, label=%u, replace=%d)\n",
+ __FUNCTION__,
+ NIP6(*prefix), prefixlen,
+ ifindex,
+ (unsigned int)label,
+ replace);
+
+ newp = ip6addrlbl_alloc(prefix, prefixlen, ifindex, label);
+ if (IS_ERR(newp))
+ return PTR_ERR(newp);
+ spin_lock(&ip6addrlbl_table.lock);
+ ret = __ip6addrlbl_add(newp, replace);
+ spin_unlock(&ip6addrlbl_table.lock);
+ if (ret)
+ ip6addrlbl_free(newp);
+ return ret;
+}
+
+/* remove a label */
+int __ip6addrlbl_del(const struct in6_addr *prefix, int prefixlen,
+ int ifindex)
+{
+ struct ip6addrlbl_entry *p = NULL;
+ struct hlist_node *pos, *n;
+ int ret = -ESRCH;
+
+ ADDRLABEL(KERN_DEBUG "%s(prefix=" NIP6_FMT ", prefixlen=%d, ifindex=%d)\n",
+ __FUNCTION__,
+ NIP6(*prefix), prefixlen,
+ ifindex);
+
+ hlist_for_each_entry_safe(p, pos, n, &ip6addrlbl_table.head, list) {
+ if (p->prefixlen == prefixlen &&
+ p->ifindex == ifindex &&
+ ipv6_addr_equal(&p->prefix, prefix)) {
+ hlist_del_rcu(&p->list);
+ ip6addrlbl_put(p);
+ call_rcu(&p->rcu, ip6addrlbl_free_rcu);
+ ret = 0;
+ break;
+ }
+ }
+ return ret;
+}
+
+int ip6addrlbl_del(const struct in6_addr *prefix, int prefixlen,
+ int ifindex)
+{
+ struct in6_addr prefix_buf;
+ int ret;
+
+ ADDRLABEL(KERN_DEBUG "%s(prefix=" NIP6_FMT ", prefixlen=%d, ifindex=%d)\n",
+ __FUNCTION__,
+ NIP6(*prefix), prefixlen,
+ ifindex);
+
+ ipv6_addr_prefix(&prefix_buf, prefix, prefixlen);
+ spin_lock(&ip6addrlbl_table.lock);
+ ret = __ip6addrlbl_del(&prefix_buf, prefixlen, ifindex);
+ spin_unlock(&ip6addrlbl_table.lock);
+ return ret;
+}
+
+/* add default label */
+static __init int ip6addrlbl_init(void)
+{
+ int err = 0;
+ int i;
+
+ ADDRLABEL(KERN_DEBUG "%s()\n", __FUNCTION__);
+
+ for (i = 0; i < ARRAY_SIZE(ip6addrlbl_init_table); i++) {
+ int ret = ip6addrlbl_add(ip6addrlbl_init_table[i].prefix,
+ ip6addrlbl_init_table[i].prefixlen,
+ 0,
+ ip6addrlbl_init_table[i].label, 0);
+ /* XXX: should we free all rules when we catch an error? */
+ if (ret && (!err || err != -ENOMEM))
+ err = ret;
+ }
+ return err;
+}
+
+int __init ipv6_addr_label_init(void)
+{
+ spin_lock_init(&ip6addrlbl_table.lock);
+
+ return ip6addrlbl_init();
+}
+
+static const struct nla_policy ifal_policy[IFAL_MAX+1] = {
+ [IFAL_ADDRESS] = { .len = sizeof(struct in6_addr), },
+ [IFAL_LABEL] = { .len = sizeof(u32), },
+};
+
+static int ip6addrlbl_newdel(struct sk_buff *skb, struct nlmsghdr *nlh,
+ void *arg)
+{
+ 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);
+ 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 &&
+ !__dev_get_by_index(&init_net, ifal->ifal_index))
+ return -EINVAL;
+
+ if (!tb[IFAL_ADDRESS])
+ return -EINVAL;
+
+ pfx = nla_data(tb[IFAL_ADDRESS]);
+ if (!pfx)
+ return -EINVAL;
+
+ 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:
+ err = ip6addrlbl_add(pfx, ifal->ifal_prefixlen,
+ ifal->ifal_index, label,
+ nlh->nlmsg_flags & NLM_F_REPLACE);
+ break;
+ case RTM_DELADDRLABEL:
+ err = ip6addrlbl_del(pfx, ifal->ifal_prefixlen,
+ ifal->ifal_index);
+ break;
+ default:
+ err = -EOPNOTSUPP;
+ }
+ return err;
+}
+
+static inline 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 pid, u32 seq, int event,
+ unsigned int flags)
+{
+ struct nlmsghdr *nlh = nlmsg_put(skb, pid, seq, event,
+ sizeof(struct ifaddrlblmsg), flags);
+ if (!nlh)
+ return -EMSGSIZE;
+
+ ip6addrlbl_putmsg(nlh, p->prefixlen, p->ifindex, lseq);
+
+ if (nla_put(skb, IFAL_ADDRESS, 16, &p->prefix) < 0 ||
+ nla_put_u32(skb, IFAL_LABEL, p->label) < 0) {
+ nlmsg_cancel(skb, nlh);
+ return -EMSGSIZE;
+ }
+
+ return nlmsg_end(skb, nlh);
+}
+
+static int ip6addrlbl_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+ struct ip6addrlbl_entry *p;
+ struct hlist_node *pos;
+ int idx = 0, s_idx = cb->args[0];
+ int err;
+
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(p, pos, &ip6addrlbl_table.head, list) {
+ if (idx >= s_idx) {
+ if ((err = ip6addrlbl_fill(skb, p,
+ ip6addrlbl_table.seq,
+ NETLINK_CB(cb->skb).pid,
+ cb->nlh->nlmsg_seq,
+ RTM_NEWADDRLABEL,
+ NLM_F_MULTI)) <= 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,
+ void *arg)
+{
+ 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);
+ 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 &&
+ !__dev_get_by_index(&init_net, ifal->ifal_index))
+ return -EINVAL;
+
+ if (!tb[IFAL_ADDRESS])
+ return -EINVAL;
+
+ addr = nla_data(tb[IFAL_ADDRESS]);
+ if (!addr)
+ return -EINVAL;
+
+ rcu_read_lock();
+ p = __ipv6_addr_label(addr, ipv6_addr_type(addr), ifal->ifal_index);
+ if (p && ip6addrlbl_hold(p))
+ p = NULL;
+ lseq = ip6addrlbl_table.seq;
+ rcu_read_unlock();
+
+ if (!p) {
+ err = -ESRCH;
+ goto out;
+ }
+
+ if (!(skb = nlmsg_new(ip6addrlbl_msgsize(), GFP_KERNEL))) {
+ ip6addrlbl_put(p);
+ return -ENOBUFS;
+ }
+
+ err = ip6addrlbl_fill(skb, p, lseq,
+ NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
+ RTM_NEWADDRLABEL, 0);
+
+ ip6addrlbl_put(p);
+
+ if (err < 0) {
+ WARN_ON(err == -EMSGSIZE);
+ kfree_skb(skb);
+ goto out;
+ }
+
+ err = rtnl_unicast(skb, NETLINK_CB(in_skb).pid);
+out:
+ return err;
+}
+
+void __init ipv6_addr_label_rtnl_register(void)
+{
+ __rtnl_register(PF_INET6, RTM_NEWADDRLABEL, ip6addrlbl_newdel, NULL);
+ __rtnl_register(PF_INET6, RTM_DELADDRLABEL, ip6addrlbl_newdel, NULL);
+ __rtnl_register(PF_INET6, RTM_GETADDRLABEL, ip6addrlbl_get, ip6addrlbl_dump);
+}
+
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