ndisc.h
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _NDISC_H
#define _NDISC_H
#include <net/ipv6_stubs.h>
/*
* ICMP codes for neighbour discovery messages
*/
#define NDISC_ROUTER_SOLICITATION 133
#define NDISC_ROUTER_ADVERTISEMENT 134
#define NDISC_NEIGHBOUR_SOLICITATION 135
#define NDISC_NEIGHBOUR_ADVERTISEMENT 136
#define NDISC_REDIRECT 137
/*
* Router type: cross-layer information from link-layer to
* IPv6 layer reported by certain link types (e.g., RFC4214).
*/
#define NDISC_NODETYPE_UNSPEC 0 /* unspecified (default) */
#define NDISC_NODETYPE_HOST 1 /* host or unauthorized router */
#define NDISC_NODETYPE_NODEFAULT 2 /* non-default router */
#define NDISC_NODETYPE_DEFAULT 3 /* default router */
/*
* ndisc options
*/
enum {
__ND_OPT_PREFIX_INFO_END = 0,
ND_OPT_SOURCE_LL_ADDR = 1, /* RFC2461 */
ND_OPT_TARGET_LL_ADDR = 2, /* RFC2461 */
ND_OPT_PREFIX_INFO = 3, /* RFC2461 */
ND_OPT_REDIRECT_HDR = 4, /* RFC2461 */
ND_OPT_MTU = 5, /* RFC2461 */
ND_OPT_NONCE = 14, /* RFC7527 */
__ND_OPT_ARRAY_MAX,
ND_OPT_ROUTE_INFO = 24, /* RFC4191 */
ND_OPT_RDNSS = 25, /* RFC5006 */
ND_OPT_DNSSL = 31, /* RFC6106 */
ND_OPT_6CO = 34, /* RFC6775 */
ND_OPT_CAPTIVE_PORTAL = 37, /* RFC7710 */
__ND_OPT_MAX
};
#define MAX_RTR_SOLICITATION_DELAY HZ
#define ND_REACHABLE_TIME (30*HZ)
#define ND_RETRANS_TIMER HZ
#include <linux/compiler.h>
#include <linux/icmpv6.h>
#include <linux/in6.h>
#include <linux/types.h>
#include <linux/if_arp.h>
#include <linux/netdevice.h>
#include <linux/hash.h>
#include <net/neighbour.h>
/* Set to 3 to get tracing... */
#define ND_DEBUG 1
#define ND_PRINTK(val, level, fmt, ...) \
do { \
if (val <= ND_DEBUG) \
net_##level##_ratelimited(fmt, ##__VA_ARGS__); \
} while (0)
struct ctl_table;
struct inet6_dev;
struct net_device;
struct net_proto_family;
struct sk_buff;
struct prefix_info;
extern struct neigh_table nd_tbl;
struct nd_msg {
struct icmp6hdr icmph;
struct in6_addr target;
__u8 opt[0];
};
struct rs_msg {
struct icmp6hdr icmph;
__u8 opt[0];
};
struct ra_msg {
struct icmp6hdr icmph;
__be32 reachable_time;
__be32 retrans_timer;
};
struct rd_msg {
struct icmp6hdr icmph;
struct in6_addr target;
struct in6_addr dest;
__u8 opt[0];
};
struct nd_opt_hdr {
__u8 nd_opt_type;
__u8 nd_opt_len;
} __packed;
/* ND options */
struct ndisc_options {
struct nd_opt_hdr *nd_opt_array[__ND_OPT_ARRAY_MAX];
#ifdef CONFIG_IPV6_ROUTE_INFO
struct nd_opt_hdr *nd_opts_ri;
struct nd_opt_hdr *nd_opts_ri_end;
#endif
struct nd_opt_hdr *nd_useropts;
struct nd_opt_hdr *nd_useropts_end;
#if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
struct nd_opt_hdr *nd_802154_opt_array[ND_OPT_TARGET_LL_ADDR + 1];
#endif
};
#define nd_opts_src_lladdr nd_opt_array[ND_OPT_SOURCE_LL_ADDR]
#define nd_opts_tgt_lladdr nd_opt_array[ND_OPT_TARGET_LL_ADDR]
#define nd_opts_pi nd_opt_array[ND_OPT_PREFIX_INFO]
#define nd_opts_pi_end nd_opt_array[__ND_OPT_PREFIX_INFO_END]
#define nd_opts_rh nd_opt_array[ND_OPT_REDIRECT_HDR]
#define nd_opts_mtu nd_opt_array[ND_OPT_MTU]
#define nd_opts_nonce nd_opt_array[ND_OPT_NONCE]
#define nd_802154_opts_src_lladdr nd_802154_opt_array[ND_OPT_SOURCE_LL_ADDR]
#define nd_802154_opts_tgt_lladdr nd_802154_opt_array[ND_OPT_TARGET_LL_ADDR]
#define NDISC_OPT_SPACE(len) (((len)+2+7)&~7)
struct ndisc_options *ndisc_parse_options(const struct net_device *dev,
u8 *opt, int opt_len,
struct ndisc_options *ndopts);
void __ndisc_fill_addr_option(struct sk_buff *skb, int type, void *data,
int data_len, int pad);
#define NDISC_OPS_REDIRECT_DATA_SPACE 2
/*
* This structure defines the hooks for IPv6 neighbour discovery.
* The following hooks can be defined; unless noted otherwise, they are
* optional and can be filled with a null pointer.
*
* int (*is_useropt)(u8 nd_opt_type):
* This function is called when IPv6 decide RA userspace options. if
* this function returns 1 then the option given by nd_opt_type will
* be handled as userspace option additional to the IPv6 options.
*
* int (*parse_options)(const struct net_device *dev,
* struct nd_opt_hdr *nd_opt,
* struct ndisc_options *ndopts):
* This function is called while parsing ndisc ops and put each position
* as pointer into ndopts. If this function return unequal 0, then this
* function took care about the ndisc option, if 0 then the IPv6 ndisc
* option parser will take care about that option.
*
* void (*update)(const struct net_device *dev, struct neighbour *n,
* u32 flags, u8 icmp6_type,
* const struct ndisc_options *ndopts):
* This function is called when IPv6 ndisc updates the neighbour cache
* entry. Additional options which can be updated may be previously
* parsed by parse_opts callback and accessible over ndopts parameter.
*
* int (*opt_addr_space)(const struct net_device *dev, u8 icmp6_type,
* struct neighbour *neigh, u8 *ha_buf,
* u8 **ha):
* This function is called when the necessary option space will be
* calculated before allocating a skb. The parameters neigh, ha_buf
* abd ha are available on NDISC_REDIRECT messages only.
*
* void (*fill_addr_option)(const struct net_device *dev,
* struct sk_buff *skb, u8 icmp6_type,
* const u8 *ha):
* This function is called when the skb will finally fill the option
* fields inside skb. NOTE: this callback should fill the option
* fields to the skb which are previously indicated by opt_space
* parameter. That means the decision to add such option should
* not lost between these two callbacks, e.g. protected by interface
* up state.
*
* void (*prefix_rcv_add_addr)(struct net *net, struct net_device *dev,
* const struct prefix_info *pinfo,
* struct inet6_dev *in6_dev,
* struct in6_addr *addr,
* int addr_type, u32 addr_flags,
* bool sllao, bool tokenized,
* __u32 valid_lft, u32 prefered_lft,
* bool dev_addr_generated):
* This function is called when a RA messages is received with valid
* PIO option fields and an IPv6 address will be added to the interface
* for autoconfiguration. The parameter dev_addr_generated reports about
* if the address was based on dev->dev_addr or not. This can be used
* to add a second address if link-layer operates with two link layer
* addresses. E.g. 802.15.4 6LoWPAN.
*/
struct ndisc_ops {
int (*is_useropt)(u8 nd_opt_type);
int (*parse_options)(const struct net_device *dev,
struct nd_opt_hdr *nd_opt,
struct ndisc_options *ndopts);
void (*update)(const struct net_device *dev, struct neighbour *n,
u32 flags, u8 icmp6_type,
const struct ndisc_options *ndopts);
int (*opt_addr_space)(const struct net_device *dev, u8 icmp6_type,
struct neighbour *neigh, u8 *ha_buf,
u8 **ha);
void (*fill_addr_option)(const struct net_device *dev,
struct sk_buff *skb, u8 icmp6_type,
const u8 *ha);
void (*prefix_rcv_add_addr)(struct net *net, struct net_device *dev,
const struct prefix_info *pinfo,
struct inet6_dev *in6_dev,
struct in6_addr *addr,
int addr_type, u32 addr_flags,
bool sllao, bool tokenized,
__u32 valid_lft, u32 prefered_lft,
bool dev_addr_generated);
};
#if IS_ENABLED(CONFIG_IPV6)
static inline int ndisc_ops_is_useropt(const struct net_device *dev,
u8 nd_opt_type)
{
if (dev->ndisc_ops && dev->ndisc_ops->is_useropt)
return dev->ndisc_ops->is_useropt(nd_opt_type);
else
return 0;
}
static inline int ndisc_ops_parse_options(const struct net_device *dev,
struct nd_opt_hdr *nd_opt,
struct ndisc_options *ndopts)
{
if (dev->ndisc_ops && dev->ndisc_ops->parse_options)
return dev->ndisc_ops->parse_options(dev, nd_opt, ndopts);
else
return 0;
}
static inline void ndisc_ops_update(const struct net_device *dev,
struct neighbour *n, u32 flags,
u8 icmp6_type,
const struct ndisc_options *ndopts)
{
if (dev->ndisc_ops && dev->ndisc_ops->update)
dev->ndisc_ops->update(dev, n, flags, icmp6_type, ndopts);
}
static inline int ndisc_ops_opt_addr_space(const struct net_device *dev,
u8 icmp6_type)
{
if (dev->ndisc_ops && dev->ndisc_ops->opt_addr_space &&
icmp6_type != NDISC_REDIRECT)
return dev->ndisc_ops->opt_addr_space(dev, icmp6_type, NULL,
NULL, NULL);
else
return 0;
}
static inline int ndisc_ops_redirect_opt_addr_space(const struct net_device *dev,
struct neighbour *neigh,
u8 *ha_buf, u8 **ha)
{
if (dev->ndisc_ops && dev->ndisc_ops->opt_addr_space)
return dev->ndisc_ops->opt_addr_space(dev, NDISC_REDIRECT,
neigh, ha_buf, ha);
else
return 0;
}
static inline void ndisc_ops_fill_addr_option(const struct net_device *dev,
struct sk_buff *skb,
u8 icmp6_type)
{
if (dev->ndisc_ops && dev->ndisc_ops->fill_addr_option &&
icmp6_type != NDISC_REDIRECT)
dev->ndisc_ops->fill_addr_option(dev, skb, icmp6_type, NULL);
}
static inline void ndisc_ops_fill_redirect_addr_option(const struct net_device *dev,
struct sk_buff *skb,
const u8 *ha)
{
if (dev->ndisc_ops && dev->ndisc_ops->fill_addr_option)
dev->ndisc_ops->fill_addr_option(dev, skb, NDISC_REDIRECT, ha);
}
static inline void ndisc_ops_prefix_rcv_add_addr(struct net *net,
struct net_device *dev,
const struct prefix_info *pinfo,
struct inet6_dev *in6_dev,
struct in6_addr *addr,
int addr_type, u32 addr_flags,
bool sllao, bool tokenized,
__u32 valid_lft,
u32 prefered_lft,
bool dev_addr_generated)
{
if (dev->ndisc_ops && dev->ndisc_ops->prefix_rcv_add_addr)
dev->ndisc_ops->prefix_rcv_add_addr(net, dev, pinfo, in6_dev,
addr, addr_type,
addr_flags, sllao,
tokenized, valid_lft,
prefered_lft,
dev_addr_generated);
}
#endif
/*
* Return the padding between the option length and the start of the
* link addr. Currently only IP-over-InfiniBand needs this, although
* if RFC 3831 IPv6-over-Fibre Channel is ever implemented it may
* also need a pad of 2.
*/
static inline int ndisc_addr_option_pad(unsigned short type)
{
switch (type) {
case ARPHRD_INFINIBAND: return 2;
default: return 0;
}
}
static inline int __ndisc_opt_addr_space(unsigned char addr_len, int pad)
{
return NDISC_OPT_SPACE(addr_len + pad);
}
#if IS_ENABLED(CONFIG_IPV6)
static inline int ndisc_opt_addr_space(struct net_device *dev, u8 icmp6_type)
{
return __ndisc_opt_addr_space(dev->addr_len,
ndisc_addr_option_pad(dev->type)) +
ndisc_ops_opt_addr_space(dev, icmp6_type);
}
static inline int ndisc_redirect_opt_addr_space(struct net_device *dev,
struct neighbour *neigh,
u8 *ops_data_buf,
u8 **ops_data)
{
return __ndisc_opt_addr_space(dev->addr_len,
ndisc_addr_option_pad(dev->type)) +
ndisc_ops_redirect_opt_addr_space(dev, neigh, ops_data_buf,
ops_data);
}
#endif
static inline u8 *__ndisc_opt_addr_data(struct nd_opt_hdr *p,
unsigned char addr_len, int prepad)
{
u8 *lladdr = (u8 *)(p + 1);
int lladdrlen = p->nd_opt_len << 3;
if (lladdrlen != __ndisc_opt_addr_space(addr_len, prepad))
return NULL;
return lladdr + prepad;
}
static inline u8 *ndisc_opt_addr_data(struct nd_opt_hdr *p,
struct net_device *dev)
{
return __ndisc_opt_addr_data(p, dev->addr_len,
ndisc_addr_option_pad(dev->type));
}
static inline u32 ndisc_hashfn(const void *pkey, const struct net_device *dev, __u32 *hash_rnd)
{
const u32 *p32 = pkey;
return (((p32[0] ^ hash32_ptr(dev)) * hash_rnd[0]) +
(p32[1] * hash_rnd[1]) +
(p32[2] * hash_rnd[2]) +
(p32[3] * hash_rnd[3]));
}
static inline struct neighbour *__ipv6_neigh_lookup_noref(struct net_device *dev, const void *pkey)
{
return ___neigh_lookup_noref(&nd_tbl, neigh_key_eq128, ndisc_hashfn, pkey, dev);
}
static inline
struct neighbour *__ipv6_neigh_lookup_noref_stub(struct net_device *dev,
const void *pkey)
{
return ___neigh_lookup_noref(ipv6_stub->nd_tbl, neigh_key_eq128,
ndisc_hashfn, pkey, dev);
}
static inline struct neighbour *__ipv6_neigh_lookup(struct net_device *dev, const void *pkey)
{
struct neighbour *n;
rcu_read_lock_bh();
n = __ipv6_neigh_lookup_noref(dev, pkey);
if (n && !refcount_inc_not_zero(&n->refcnt))
n = NULL;
rcu_read_unlock_bh();
return n;
}
static inline void __ipv6_confirm_neigh(struct net_device *dev,
const void *pkey)
{
struct neighbour *n;
rcu_read_lock_bh();
n = __ipv6_neigh_lookup_noref(dev, pkey);
if (n) {
unsigned long now = jiffies;
/* avoid dirtying neighbour */
if (READ_ONCE(n->confirmed) != now)
WRITE_ONCE(n->confirmed, now);
}
rcu_read_unlock_bh();
}
static inline void __ipv6_confirm_neigh_stub(struct net_device *dev,
const void *pkey)
{
struct neighbour *n;
rcu_read_lock_bh();
n = __ipv6_neigh_lookup_noref_stub(dev, pkey);
if (n) {
unsigned long now = jiffies;
/* avoid dirtying neighbour */
if (READ_ONCE(n->confirmed) != now)
WRITE_ONCE(n->confirmed, now);
}
rcu_read_unlock_bh();
}
/* uses ipv6_stub and is meant for use outside of IPv6 core */
static inline struct neighbour *ip_neigh_gw6(struct net_device *dev,
const void *addr)
{
struct neighbour *neigh;
neigh = __ipv6_neigh_lookup_noref_stub(dev, addr);
if (unlikely(!neigh))
neigh = __neigh_create(ipv6_stub->nd_tbl, addr, dev, false);
return neigh;
}
int ndisc_init(void);
int ndisc_late_init(void);
void ndisc_late_cleanup(void);
void ndisc_cleanup(void);
int ndisc_rcv(struct sk_buff *skb);
void ndisc_send_ns(struct net_device *dev, const struct in6_addr *solicit,
const struct in6_addr *daddr, const struct in6_addr *saddr,
u64 nonce);
void ndisc_send_rs(struct net_device *dev,
const struct in6_addr *saddr, const struct in6_addr *daddr);
void ndisc_send_na(struct net_device *dev, const struct in6_addr *daddr,
const struct in6_addr *solicited_addr,
bool router, bool solicited, bool override, bool inc_opt);
void ndisc_send_redirect(struct sk_buff *skb, const struct in6_addr *target);
int ndisc_mc_map(const struct in6_addr *addr, char *buf, struct net_device *dev,
int dir);
void ndisc_update(const struct net_device *dev, struct neighbour *neigh,
const u8 *lladdr, u8 new, u32 flags, u8 icmp6_type,
struct ndisc_options *ndopts);
/*
* IGMP
*/
int igmp6_init(void);
int igmp6_late_init(void);
void igmp6_cleanup(void);
void igmp6_late_cleanup(void);
int igmp6_event_query(struct sk_buff *skb);
int igmp6_event_report(struct sk_buff *skb);
#ifdef CONFIG_SYSCTL
int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write,
void __user *buffer, size_t *lenp, loff_t *ppos);
int ndisc_ifinfo_sysctl_strategy(struct ctl_table *ctl,
void __user *oldval, size_t __user *oldlenp,
void __user *newval, size_t newlen);
#endif
void inet6_ifinfo_notify(int event, struct inet6_dev *idev);
#endif