Commit 2a8cc6c8 authored by YOSHIFUJI Hideaki's avatar YOSHIFUJI Hideaki Committed by David S. Miller

[IPV6] ADDRCONF: Support RFC3484 configurable address selection policy table.

Policy table is implemented as an RCU linear list since we do not expect
large list nor frequent updates.
Signed-off-by: default avatarYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 303065a8
/*
* if_addrlabel.h - netlink interface for address labels
*
* Copyright (C)2007 USAGI/WIDE Project, All Rights Reserved.
*
* Authors:
* YOSHIFUJI Hideaki @ USAGI/WIDE <yoshfuji@linux-ipv6.org>
*/
#ifndef __LINUX_IF_ADDRLABEL_H
#define __LINUX_IF_ADDRLABEL_H
struct ifaddrlblmsg
{
__u8 ifal_family; /* Address family */
__u8 __ifal_reserved; /* Reserved */
__u8 ifal_prefixlen; /* Prefix length */
__u8 ifal_flags; /* Flags */
__u32 ifal_index; /* Link index */
__u32 ifal_seq; /* sequence number */
};
enum
{
IFAL_ADDRESS = 1,
IFAL_LABEL = 2,
__IFAL_MAX
};
#define IFAL_MAX (__IFAL_MAX - 1)
#endif
......@@ -100,6 +100,13 @@ enum {
RTM_NEWNDUSEROPT = 68,
#define RTM_NEWNDUSEROPT RTM_NEWNDUSEROPT
RTM_NEWADDRLABEL = 72,
#define RTM_NEWADDRLABEL RTM_NEWADDRLABEL
RTM_DELADDRLABEL,
#define RTM_NEWADDRLABEL RTM_NEWADDRLABEL
RTM_GETADDRLABEL,
#define RTM_GETADDRLABEL RTM_GETADDRLABEL
__RTM_MAX,
#define RTM_MAX (((__RTM_MAX + 3) & ~3) - 1)
};
......
......@@ -83,6 +83,14 @@ extern void addrconf_join_solict(struct net_device *dev,
extern void addrconf_leave_solict(struct inet6_dev *idev,
struct in6_addr *addr);
/*
* IPv6 Address Label subsystem (addrlabel.c)
*/
extern int ipv6_addr_label_init(void);
extern void ipv6_addr_label_rtnl_register(void);
extern u32 ipv6_addr_label(const struct in6_addr *addr,
int type, int ifindex);
/*
* multicast prototypes (mcast.c)
*/
......
......@@ -5,6 +5,7 @@
obj-$(CONFIG_IPV6) += ipv6.o
ipv6-objs := af_inet6.o anycast.o ip6_output.o ip6_input.o addrconf.o \
addrlabel.o \
route.o ip6_fib.o ipv6_sockglue.o ndisc.o udp.o udplite.o \
raw.o protocol.o icmp.o mcast.o reassembly.o tcp_ipv6.o \
exthdrs.o sysctl_net_ipv6.o datagram.o \
......
......@@ -874,36 +874,6 @@ static inline int ipv6_saddr_preferred(int type)
return 0;
}
/* static matching label */
static inline int ipv6_addr_label(const struct in6_addr *addr, int type,
int ifindex)
{
/*
* prefix (longest match) label
* -----------------------------
* ::1/128 0
* ::/0 1
* 2002::/16 2
* ::/96 3
* ::ffff:0:0/96 4
* fc00::/7 5
* 2001::/32 6
*/
if (type & IPV6_ADDR_LOOPBACK)
return 0;
else if (type & IPV6_ADDR_COMPATv4)
return 3;
else if (type & IPV6_ADDR_MAPPED)
return 4;
else if (addr->s6_addr32[0] == htonl(0x20010000))
return 6;
else if (addr->s6_addr16[0] == htons(0x2002))
return 2;
else if ((addr->s6_addr[0] & 0xfe) == 0xfc)
return 5;
return 1;
}
int ipv6_dev_get_saddr(struct net_device *daddr_dev,
struct in6_addr *daddr, struct in6_addr *saddr)
{
......@@ -4189,7 +4159,13 @@ EXPORT_SYMBOL(unregister_inet6addr_notifier);
int __init addrconf_init(void)
{
int err = 0;
int err;
if ((err = ipv6_addr_label_init()) < 0) {
printk(KERN_CRIT "IPv6 Addrconf: cannot initialize default policy table: %d.\n",
err);
return err;
}
/* The addrconf netdev notifier requires that loopback_dev
* has it's ipv6 private information allocated and setup
......@@ -4240,6 +4216,8 @@ int __init addrconf_init(void)
__rtnl_register(PF_INET6, RTM_GETMULTICAST, NULL, inet6_dump_ifmcaddr);
__rtnl_register(PF_INET6, RTM_GETANYCAST, NULL, inet6_dump_ifacaddr);
ipv6_addr_label_rtnl_register();
#ifdef CONFIG_SYSCTL
addrconf_sysctl.sysctl_header =
register_sysctl_table(addrconf_sysctl.addrconf_root_dir);
......
/*
* 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;