diff options
Diffstat (limited to 'net/ipv6/addrlabel.c')
| -rw-r--r-- | net/ipv6/addrlabel.c | 561 |
1 files changed, 561 insertions, 0 deletions
diff --git a/net/ipv6/addrlabel.c b/net/ipv6/addrlabel.c new file mode 100644 index 000000000000..a3c5a72218fd --- /dev/null +++ b/net/ipv6/addrlabel.c @@ -0,0 +1,561 @@ +/* + * 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 void ip6addrlbl_free_rcu(struct rcu_head *h) +{ + ip6addrlbl_free(container_of(h, struct ip6addrlbl_entry, rcu)); +} + +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)) + call_rcu(&p->rcu, ip6addrlbl_free_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 */ +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=" 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 */ +static 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); + 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 */ +static 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 */ +static 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); + ret = 0; + break; + } + } + return ret; +} + +static 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 net *net = skb->sk->sk_net; + struct ifaddrlblmsg *ifal; + struct nlattr *tb[IFAL_MAX+1]; + struct in6_addr *pfx; + u32 label; + int err = 0; + + if (net != &init_net) + return 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 net *net = skb->sk->sk_net; + struct ip6addrlbl_entry *p; + struct hlist_node *pos; + int idx = 0, s_idx = cb->args[0]; + int err; + + if (net != &init_net) + return 0; + + 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 net *net = in_skb->sk->sk_net; + 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; + + if (net != &init_net) + return 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; + + 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, &init_net, 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); +} + |