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Diffstat (limited to '')
| -rw-r--r-- | include/net/neighbour.h | 605 |
1 files changed, 605 insertions, 0 deletions
diff --git a/include/net/neighbour.h b/include/net/neighbour.h new file mode 100644 index 000000000..ccc4a0f8b --- /dev/null +++ b/include/net/neighbour.h @@ -0,0 +1,605 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _NET_NEIGHBOUR_H +#define _NET_NEIGHBOUR_H + +#include <linux/neighbour.h> + +/* + * Generic neighbour manipulation + * + * Authors: + * Pedro Roque <roque@di.fc.ul.pt> + * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> + * + * Changes: + * + * Harald Welte: <laforge@gnumonks.org> + * - Add neighbour cache statistics like rtstat + */ + +#include <linux/atomic.h> +#include <linux/refcount.h> +#include <linux/netdevice.h> +#include <linux/skbuff.h> +#include <linux/rcupdate.h> +#include <linux/seq_file.h> +#include <linux/bitmap.h> + +#include <linux/err.h> +#include <linux/sysctl.h> +#include <linux/workqueue.h> +#include <net/rtnetlink.h> + +/* + * NUD stands for "neighbor unreachability detection" + */ + +#define NUD_IN_TIMER (NUD_INCOMPLETE|NUD_REACHABLE|NUD_DELAY|NUD_PROBE) +#define NUD_VALID (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE|NUD_PROBE|NUD_STALE|NUD_DELAY) +#define NUD_CONNECTED (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE) + +struct neighbour; + +enum { + NEIGH_VAR_MCAST_PROBES, + NEIGH_VAR_UCAST_PROBES, + NEIGH_VAR_APP_PROBES, + NEIGH_VAR_MCAST_REPROBES, + NEIGH_VAR_RETRANS_TIME, + NEIGH_VAR_BASE_REACHABLE_TIME, + NEIGH_VAR_DELAY_PROBE_TIME, + NEIGH_VAR_INTERVAL_PROBE_TIME_MS, + NEIGH_VAR_GC_STALETIME, + NEIGH_VAR_QUEUE_LEN_BYTES, + NEIGH_VAR_PROXY_QLEN, + NEIGH_VAR_ANYCAST_DELAY, + NEIGH_VAR_PROXY_DELAY, + NEIGH_VAR_LOCKTIME, +#define NEIGH_VAR_DATA_MAX (NEIGH_VAR_LOCKTIME + 1) + /* Following are used as a second way to access one of the above */ + NEIGH_VAR_QUEUE_LEN, /* same data as NEIGH_VAR_QUEUE_LEN_BYTES */ + NEIGH_VAR_RETRANS_TIME_MS, /* same data as NEIGH_VAR_RETRANS_TIME */ + NEIGH_VAR_BASE_REACHABLE_TIME_MS, /* same data as NEIGH_VAR_BASE_REACHABLE_TIME */ + /* Following are used by "default" only */ + NEIGH_VAR_GC_INTERVAL, + NEIGH_VAR_GC_THRESH1, + NEIGH_VAR_GC_THRESH2, + NEIGH_VAR_GC_THRESH3, + NEIGH_VAR_MAX +}; + +struct neigh_parms { + possible_net_t net; + struct net_device *dev; + netdevice_tracker dev_tracker; + struct list_head list; + int (*neigh_setup)(struct neighbour *); + struct neigh_table *tbl; + + void *sysctl_table; + + int dead; + refcount_t refcnt; + struct rcu_head rcu_head; + + int reachable_time; + u32 qlen; + int data[NEIGH_VAR_DATA_MAX]; + DECLARE_BITMAP(data_state, NEIGH_VAR_DATA_MAX); +}; + +static inline void neigh_var_set(struct neigh_parms *p, int index, int val) +{ + set_bit(index, p->data_state); + p->data[index] = val; +} + +#define NEIGH_VAR(p, attr) ((p)->data[NEIGH_VAR_ ## attr]) + +/* In ndo_neigh_setup, NEIGH_VAR_INIT should be used. + * In other cases, NEIGH_VAR_SET should be used. + */ +#define NEIGH_VAR_INIT(p, attr, val) (NEIGH_VAR(p, attr) = val) +#define NEIGH_VAR_SET(p, attr, val) neigh_var_set(p, NEIGH_VAR_ ## attr, val) + +static inline void neigh_parms_data_state_setall(struct neigh_parms *p) +{ + bitmap_fill(p->data_state, NEIGH_VAR_DATA_MAX); +} + +static inline void neigh_parms_data_state_cleanall(struct neigh_parms *p) +{ + bitmap_zero(p->data_state, NEIGH_VAR_DATA_MAX); +} + +struct neigh_statistics { + unsigned long allocs; /* number of allocated neighs */ + unsigned long destroys; /* number of destroyed neighs */ + unsigned long hash_grows; /* number of hash resizes */ + + unsigned long res_failed; /* number of failed resolutions */ + + unsigned long lookups; /* number of lookups */ + unsigned long hits; /* number of hits (among lookups) */ + + unsigned long rcv_probes_mcast; /* number of received mcast ipv6 */ + unsigned long rcv_probes_ucast; /* number of received ucast ipv6 */ + + unsigned long periodic_gc_runs; /* number of periodic GC runs */ + unsigned long forced_gc_runs; /* number of forced GC runs */ + + unsigned long unres_discards; /* number of unresolved drops */ + unsigned long table_fulls; /* times even gc couldn't help */ +}; + +#define NEIGH_CACHE_STAT_INC(tbl, field) this_cpu_inc((tbl)->stats->field) + +struct neighbour { + struct neighbour __rcu *next; + struct neigh_table *tbl; + struct neigh_parms *parms; + unsigned long confirmed; + unsigned long updated; + rwlock_t lock; + refcount_t refcnt; + unsigned int arp_queue_len_bytes; + struct sk_buff_head arp_queue; + struct timer_list timer; + unsigned long used; + atomic_t probes; + u8 nud_state; + u8 type; + u8 dead; + u8 protocol; + u32 flags; + seqlock_t ha_lock; + unsigned char ha[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))] __aligned(8); + struct hh_cache hh; + int (*output)(struct neighbour *, struct sk_buff *); + const struct neigh_ops *ops; + struct list_head gc_list; + struct list_head managed_list; + struct rcu_head rcu; + struct net_device *dev; + netdevice_tracker dev_tracker; + u8 primary_key[0]; +} __randomize_layout; + +struct neigh_ops { + int family; + void (*solicit)(struct neighbour *, struct sk_buff *); + void (*error_report)(struct neighbour *, struct sk_buff *); + int (*output)(struct neighbour *, struct sk_buff *); + int (*connected_output)(struct neighbour *, struct sk_buff *); +}; + +struct pneigh_entry { + struct pneigh_entry *next; + possible_net_t net; + struct net_device *dev; + netdevice_tracker dev_tracker; + u32 flags; + u8 protocol; + u32 key[]; +}; + +/* + * neighbour table manipulation + */ + +#define NEIGH_NUM_HASH_RND 4 + +struct neigh_hash_table { + struct neighbour __rcu **hash_buckets; + unsigned int hash_shift; + __u32 hash_rnd[NEIGH_NUM_HASH_RND]; + struct rcu_head rcu; +}; + + +struct neigh_table { + int family; + unsigned int entry_size; + unsigned int key_len; + __be16 protocol; + __u32 (*hash)(const void *pkey, + const struct net_device *dev, + __u32 *hash_rnd); + bool (*key_eq)(const struct neighbour *, const void *pkey); + int (*constructor)(struct neighbour *); + int (*pconstructor)(struct pneigh_entry *); + void (*pdestructor)(struct pneigh_entry *); + void (*proxy_redo)(struct sk_buff *skb); + int (*is_multicast)(const void *pkey); + bool (*allow_add)(const struct net_device *dev, + struct netlink_ext_ack *extack); + char *id; + struct neigh_parms parms; + struct list_head parms_list; + int gc_interval; + int gc_thresh1; + int gc_thresh2; + int gc_thresh3; + unsigned long last_flush; + struct delayed_work gc_work; + struct delayed_work managed_work; + struct timer_list proxy_timer; + struct sk_buff_head proxy_queue; + atomic_t entries; + atomic_t gc_entries; + struct list_head gc_list; + struct list_head managed_list; + rwlock_t lock; + unsigned long last_rand; + struct neigh_statistics __percpu *stats; + struct neigh_hash_table __rcu *nht; + struct pneigh_entry **phash_buckets; +}; + +enum { + NEIGH_ARP_TABLE = 0, + NEIGH_ND_TABLE = 1, + NEIGH_DN_TABLE = 2, + NEIGH_NR_TABLES, + NEIGH_LINK_TABLE = NEIGH_NR_TABLES /* Pseudo table for neigh_xmit */ +}; + +static inline int neigh_parms_family(struct neigh_parms *p) +{ + return p->tbl->family; +} + +#define NEIGH_PRIV_ALIGN sizeof(long long) +#define NEIGH_ENTRY_SIZE(size) ALIGN((size), NEIGH_PRIV_ALIGN) + +static inline void *neighbour_priv(const struct neighbour *n) +{ + return (char *)n + n->tbl->entry_size; +} + +/* flags for neigh_update() */ +#define NEIGH_UPDATE_F_OVERRIDE BIT(0) +#define NEIGH_UPDATE_F_WEAK_OVERRIDE BIT(1) +#define NEIGH_UPDATE_F_OVERRIDE_ISROUTER BIT(2) +#define NEIGH_UPDATE_F_USE BIT(3) +#define NEIGH_UPDATE_F_MANAGED BIT(4) +#define NEIGH_UPDATE_F_EXT_LEARNED BIT(5) +#define NEIGH_UPDATE_F_ISROUTER BIT(6) +#define NEIGH_UPDATE_F_ADMIN BIT(7) + +/* In-kernel representation for NDA_FLAGS_EXT flags: */ +#define NTF_OLD_MASK 0xff +#define NTF_EXT_SHIFT 8 +#define NTF_EXT_MASK (NTF_EXT_MANAGED) + +#define NTF_MANAGED (NTF_EXT_MANAGED << NTF_EXT_SHIFT) + +extern const struct nla_policy nda_policy[]; + +static inline bool neigh_key_eq32(const struct neighbour *n, const void *pkey) +{ + return *(const u32 *)n->primary_key == *(const u32 *)pkey; +} + +static inline bool neigh_key_eq128(const struct neighbour *n, const void *pkey) +{ + const u32 *n32 = (const u32 *)n->primary_key; + const u32 *p32 = pkey; + + return ((n32[0] ^ p32[0]) | (n32[1] ^ p32[1]) | + (n32[2] ^ p32[2]) | (n32[3] ^ p32[3])) == 0; +} + +static inline struct neighbour *___neigh_lookup_noref( + struct neigh_table *tbl, + bool (*key_eq)(const struct neighbour *n, const void *pkey), + __u32 (*hash)(const void *pkey, + const struct net_device *dev, + __u32 *hash_rnd), + const void *pkey, + struct net_device *dev) +{ + struct neigh_hash_table *nht = rcu_dereference(tbl->nht); + struct neighbour *n; + u32 hash_val; + + hash_val = hash(pkey, dev, nht->hash_rnd) >> (32 - nht->hash_shift); + for (n = rcu_dereference(nht->hash_buckets[hash_val]); + n != NULL; + n = rcu_dereference(n->next)) { + if (n->dev == dev && key_eq(n, pkey)) + return n; + } + + return NULL; +} + +static inline struct neighbour *__neigh_lookup_noref(struct neigh_table *tbl, + const void *pkey, + struct net_device *dev) +{ + return ___neigh_lookup_noref(tbl, tbl->key_eq, tbl->hash, pkey, dev); +} + +static inline void neigh_confirm(struct neighbour *n) +{ + if (n) { + unsigned long now = jiffies; + + /* avoid dirtying neighbour */ + if (READ_ONCE(n->confirmed) != now) + WRITE_ONCE(n->confirmed, now); + } +} + +void neigh_table_init(int index, struct neigh_table *tbl); +int neigh_table_clear(int index, struct neigh_table *tbl); +struct neighbour *neigh_lookup(struct neigh_table *tbl, const void *pkey, + struct net_device *dev); +struct neighbour *__neigh_create(struct neigh_table *tbl, const void *pkey, + struct net_device *dev, bool want_ref); +static inline struct neighbour *neigh_create(struct neigh_table *tbl, + const void *pkey, + struct net_device *dev) +{ + return __neigh_create(tbl, pkey, dev, true); +} +void neigh_destroy(struct neighbour *neigh); +int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb, + const bool immediate_ok); +int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new, u32 flags, + u32 nlmsg_pid); +void __neigh_set_probe_once(struct neighbour *neigh); +bool neigh_remove_one(struct neighbour *ndel, struct neigh_table *tbl); +void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev); +int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev); +int neigh_carrier_down(struct neigh_table *tbl, struct net_device *dev); +int neigh_resolve_output(struct neighbour *neigh, struct sk_buff *skb); +int neigh_connected_output(struct neighbour *neigh, struct sk_buff *skb); +int neigh_direct_output(struct neighbour *neigh, struct sk_buff *skb); +struct neighbour *neigh_event_ns(struct neigh_table *tbl, + u8 *lladdr, void *saddr, + struct net_device *dev); + +struct neigh_parms *neigh_parms_alloc(struct net_device *dev, + struct neigh_table *tbl); +void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms); + +static inline +struct net *neigh_parms_net(const struct neigh_parms *parms) +{ + return read_pnet(&parms->net); +} + +unsigned long neigh_rand_reach_time(unsigned long base); + +void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p, + struct sk_buff *skb); +struct pneigh_entry *pneigh_lookup(struct neigh_table *tbl, struct net *net, + const void *key, struct net_device *dev, + int creat); +struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl, struct net *net, + const void *key, struct net_device *dev); +int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key, + struct net_device *dev); + +static inline struct net *pneigh_net(const struct pneigh_entry *pneigh) +{ + return read_pnet(&pneigh->net); +} + +void neigh_app_ns(struct neighbour *n); +void neigh_for_each(struct neigh_table *tbl, + void (*cb)(struct neighbour *, void *), void *cookie); +void __neigh_for_each_release(struct neigh_table *tbl, + int (*cb)(struct neighbour *)); +int neigh_xmit(int fam, struct net_device *, const void *, struct sk_buff *); +void pneigh_for_each(struct neigh_table *tbl, + void (*cb)(struct pneigh_entry *)); + +struct neigh_seq_state { + struct seq_net_private p; + struct neigh_table *tbl; + struct neigh_hash_table *nht; + void *(*neigh_sub_iter)(struct neigh_seq_state *state, + struct neighbour *n, loff_t *pos); + unsigned int bucket; + unsigned int flags; +#define NEIGH_SEQ_NEIGH_ONLY 0x00000001 +#define NEIGH_SEQ_IS_PNEIGH 0x00000002 +#define NEIGH_SEQ_SKIP_NOARP 0x00000004 +}; +void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *, + unsigned int); +void *neigh_seq_next(struct seq_file *, void *, loff_t *); +void neigh_seq_stop(struct seq_file *, void *); + +int neigh_proc_dointvec(struct ctl_table *ctl, int write, + void *buffer, size_t *lenp, loff_t *ppos); +int neigh_proc_dointvec_jiffies(struct ctl_table *ctl, int write, + void *buffer, + size_t *lenp, loff_t *ppos); +int neigh_proc_dointvec_ms_jiffies(struct ctl_table *ctl, int write, + void *buffer, size_t *lenp, loff_t *ppos); + +int neigh_sysctl_register(struct net_device *dev, struct neigh_parms *p, + proc_handler *proc_handler); +void neigh_sysctl_unregister(struct neigh_parms *p); + +static inline void __neigh_parms_put(struct neigh_parms *parms) +{ + refcount_dec(&parms->refcnt); +} + +static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms) +{ + refcount_inc(&parms->refcnt); + return parms; +} + +/* + * Neighbour references + */ + +static inline void neigh_release(struct neighbour *neigh) +{ + if (refcount_dec_and_test(&neigh->refcnt)) + neigh_destroy(neigh); +} + +static inline struct neighbour * neigh_clone(struct neighbour *neigh) +{ + if (neigh) + refcount_inc(&neigh->refcnt); + return neigh; +} + +#define neigh_hold(n) refcount_inc(&(n)->refcnt) + +static __always_inline int neigh_event_send_probe(struct neighbour *neigh, + struct sk_buff *skb, + const bool immediate_ok) +{ + unsigned long now = jiffies; + + if (READ_ONCE(neigh->used) != now) + WRITE_ONCE(neigh->used, now); + if (!(READ_ONCE(neigh->nud_state) & (NUD_CONNECTED | NUD_DELAY | NUD_PROBE))) + return __neigh_event_send(neigh, skb, immediate_ok); + return 0; +} + +static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb) +{ + return neigh_event_send_probe(neigh, skb, true); +} + +#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) +static inline int neigh_hh_bridge(struct hh_cache *hh, struct sk_buff *skb) +{ + unsigned int seq, hh_alen; + + do { + seq = read_seqbegin(&hh->hh_lock); + hh_alen = HH_DATA_ALIGN(ETH_HLEN); + memcpy(skb->data - hh_alen, hh->hh_data, ETH_ALEN + hh_alen - ETH_HLEN); + } while (read_seqretry(&hh->hh_lock, seq)); + return 0; +} +#endif + +static inline int neigh_hh_output(const struct hh_cache *hh, struct sk_buff *skb) +{ + unsigned int hh_alen = 0; + unsigned int seq; + unsigned int hh_len; + + do { + seq = read_seqbegin(&hh->hh_lock); + hh_len = READ_ONCE(hh->hh_len); + if (likely(hh_len <= HH_DATA_MOD)) { + hh_alen = HH_DATA_MOD; + + /* skb_push() would proceed silently if we have room for + * the unaligned size but not for the aligned size: + * check headroom explicitly. + */ + if (likely(skb_headroom(skb) >= HH_DATA_MOD)) { + /* this is inlined by gcc */ + memcpy(skb->data - HH_DATA_MOD, hh->hh_data, + HH_DATA_MOD); + } + } else { + hh_alen = HH_DATA_ALIGN(hh_len); + + if (likely(skb_headroom(skb) >= hh_alen)) { + memcpy(skb->data - hh_alen, hh->hh_data, + hh_alen); + } + } + } while (read_seqretry(&hh->hh_lock, seq)); + + if (WARN_ON_ONCE(skb_headroom(skb) < hh_alen)) { + kfree_skb(skb); + return NET_XMIT_DROP; + } + + __skb_push(skb, hh_len); + return dev_queue_xmit(skb); +} + +static inline int neigh_output(struct neighbour *n, struct sk_buff *skb, + bool skip_cache) +{ + const struct hh_cache *hh = &n->hh; + + /* n->nud_state and hh->hh_len could be changed under us. + * neigh_hh_output() is taking care of the race later. + */ + if (!skip_cache && + (READ_ONCE(n->nud_state) & NUD_CONNECTED) && + READ_ONCE(hh->hh_len)) + return neigh_hh_output(hh, skb); + + return READ_ONCE(n->output)(n, skb); +} + +static inline struct neighbour * +__neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat) +{ + struct neighbour *n = neigh_lookup(tbl, pkey, dev); + + if (n || !creat) + return n; + + n = neigh_create(tbl, pkey, dev); + return IS_ERR(n) ? NULL : n; +} + +static inline struct neighbour * +__neigh_lookup_errno(struct neigh_table *tbl, const void *pkey, + struct net_device *dev) +{ + struct neighbour *n = neigh_lookup(tbl, pkey, dev); + + if (n) + return n; + + return neigh_create(tbl, pkey, dev); +} + +struct neighbour_cb { + unsigned long sched_next; + unsigned int flags; +}; + +#define LOCALLY_ENQUEUED 0x1 + +#define NEIGH_CB(skb) ((struct neighbour_cb *)(skb)->cb) + +static inline void neigh_ha_snapshot(char *dst, const struct neighbour *n, + const struct net_device *dev) +{ + unsigned int seq; + + do { + seq = read_seqbegin(&n->ha_lock); + memcpy(dst, n->ha, dev->addr_len); + } while (read_seqretry(&n->ha_lock, seq)); +} + +static inline void neigh_update_is_router(struct neighbour *neigh, u32 flags, + int *notify) +{ + u8 ndm_flags = 0; + + ndm_flags |= (flags & NEIGH_UPDATE_F_ISROUTER) ? NTF_ROUTER : 0; + if ((neigh->flags ^ ndm_flags) & NTF_ROUTER) { + if (ndm_flags & NTF_ROUTER) + neigh->flags |= NTF_ROUTER; + else + neigh->flags &= ~NTF_ROUTER; + *notify = 1; + } +} +#endif |