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-rw-r--r--include/net/neighbour.h603
1 files changed, 603 insertions, 0 deletions
diff --git a/include/net/neighbour.h b/include/net/neighbour.h
new file mode 100644
index 0000000000..0d28172193
--- /dev/null
+++ b/include/net/neighbour.h
@@ -0,0 +1,603 @@
+/* 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[];
+} __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 *);
+
+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
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-27 09:11:39 +0000