| /* 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 <linux/android_kabi.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); |
| |
| ANDROID_KABI_RESERVE(1); |
| }; |
| |
| 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; |
| |
| ANDROID_KABI_RESERVE(1); |
| |
| 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; |
| |
| ANDROID_KABI_RESERVE(1); |
| }; |
| |
| 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_bh(tbl->nht); |
| struct neighbour *n; |
| u32 hash_val; |
| |
| hash_val = hash(pkey, dev, nht->hash_rnd) >> (32 - nht->hash_shift); |
| for (n = rcu_dereference_bh(nht->hash_buckets[hash_val]); |
| n != NULL; |
| n = rcu_dereference_bh(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 (!(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 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 |