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