diff options
Diffstat (limited to 'net/ipv6/addrlabel.c')
-rw-r--r-- | net/ipv6/addrlabel.c | 652 |
1 files changed, 652 insertions, 0 deletions
diff --git a/net/ipv6/addrlabel.c b/net/ipv6/addrlabel.c new file mode 100644 index 0000000000..17ac45aa71 --- /dev/null +++ b/net/ipv6/addrlabel.c @@ -0,0 +1,652 @@ +// 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_deprecated(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_reserved = 0; + 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_valid_dump_req(const struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + struct ifaddrlblmsg *ifal; + + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ifal))) { + NL_SET_ERR_MSG_MOD(extack, "Invalid header for address label dump request"); + return -EINVAL; + } + + ifal = nlmsg_data(nlh); + if (ifal->__ifal_reserved || ifal->ifal_prefixlen || + ifal->ifal_flags || ifal->ifal_index || ifal->ifal_seq) { + NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for address label dump request"); + return -EINVAL; + } + + if (nlmsg_attrlen(nlh, sizeof(*ifal))) { + NL_SET_ERR_MSG_MOD(extack, "Invalid data after header for address label dump request"); + return -EINVAL; + } + + return 0; +} + +static int ip6addrlbl_dump(struct sk_buff *skb, struct netlink_callback *cb) +{ + const struct nlmsghdr *nlh = cb->nlh; + struct net *net = sock_net(skb->sk); + struct ip6addrlbl_entry *p; + int idx = 0, s_idx = cb->args[0]; + int err; + + if (cb->strict_check) { + err = ip6addrlbl_valid_dump_req(nlh, cb->extack); + if (err < 0) + return 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, + 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_valid_get_req(struct sk_buff *skb, + const struct nlmsghdr *nlh, + struct nlattr **tb, + struct netlink_ext_ack *extack) +{ + struct ifaddrlblmsg *ifal; + int i, err; + + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ifal))) { + NL_SET_ERR_MSG_MOD(extack, "Invalid header for addrlabel get request"); + return -EINVAL; + } + + if (!netlink_strict_get_check(skb)) + return nlmsg_parse_deprecated(nlh, sizeof(*ifal), tb, + IFAL_MAX, ifal_policy, extack); + + ifal = nlmsg_data(nlh); + if (ifal->__ifal_reserved || ifal->ifal_flags || ifal->ifal_seq) { + NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for addrlabel get request"); + return -EINVAL; + } + + err = nlmsg_parse_deprecated_strict(nlh, sizeof(*ifal), tb, IFAL_MAX, + ifal_policy, extack); + if (err) + return err; + + for (i = 0; i <= IFAL_MAX; i++) { + if (!tb[i]) + continue; + + switch (i) { + case IFAL_ADDRESS: + break; + default: + NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in addrlabel get request"); + return -EINVAL; + } + } + + return 0; +} + +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 = ip6addrlbl_valid_get_req(in_skb, nlh, tb, 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; +} |