11da177e4SLinus Torvalds #ifndef _NET_NEIGHBOUR_H 21da177e4SLinus Torvalds #define _NET_NEIGHBOUR_H 31da177e4SLinus Torvalds 49067c722SThomas Graf #include <linux/neighbour.h> 59067c722SThomas Graf 61da177e4SLinus Torvalds /* 71da177e4SLinus Torvalds * Generic neighbour manipulation 81da177e4SLinus Torvalds * 91da177e4SLinus Torvalds * Authors: 101da177e4SLinus Torvalds * Pedro Roque <roque@di.fc.ul.pt> 111da177e4SLinus Torvalds * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> 121da177e4SLinus Torvalds * 131da177e4SLinus Torvalds * Changes: 141da177e4SLinus Torvalds * 151da177e4SLinus Torvalds * Harald Welte: <laforge@gnumonks.org> 161da177e4SLinus Torvalds * - Add neighbour cache statistics like rtstat 171da177e4SLinus Torvalds */ 181da177e4SLinus Torvalds 191da177e4SLinus Torvalds #include <asm/atomic.h> 201da177e4SLinus Torvalds #include <linux/netdevice.h> 2114c85021SArnaldo Carvalho de Melo #include <linux/skbuff.h> 221da177e4SLinus Torvalds #include <linux/rcupdate.h> 231da177e4SLinus Torvalds #include <linux/seq_file.h> 241da177e4SLinus Torvalds 251da177e4SLinus Torvalds #include <linux/err.h> 261da177e4SLinus Torvalds #include <linux/sysctl.h> 27e4c4e448SEric Dumazet #include <linux/workqueue.h> 28c8822a4eSThomas Graf #include <net/rtnetlink.h> 291da177e4SLinus Torvalds 3039971554SPavel Emelyanov /* 3139971554SPavel Emelyanov * NUD stands for "neighbor unreachability detection" 3239971554SPavel Emelyanov */ 3339971554SPavel Emelyanov 341da177e4SLinus Torvalds #define NUD_IN_TIMER (NUD_INCOMPLETE|NUD_REACHABLE|NUD_DELAY|NUD_PROBE) 351da177e4SLinus Torvalds #define NUD_VALID (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE|NUD_PROBE|NUD_STALE|NUD_DELAY) 361da177e4SLinus Torvalds #define NUD_CONNECTED (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE) 371da177e4SLinus Torvalds 381da177e4SLinus Torvalds struct neighbour; 391da177e4SLinus Torvalds 40fd2c3ef7SEric Dumazet struct neigh_parms { 4157da52c1SYOSHIFUJI Hideaki #ifdef CONFIG_NET_NS 42426b5303SEric W. Biederman struct net *net; 4357da52c1SYOSHIFUJI Hideaki #endif 44c7fb64dbSThomas Graf struct net_device *dev; 451da177e4SLinus Torvalds struct neigh_parms *next; 461da177e4SLinus Torvalds int (*neigh_setup)(struct neighbour *); 47ecbb4169SAlexey Kuznetsov void (*neigh_cleanup)(struct neighbour *); 481da177e4SLinus Torvalds struct neigh_table *tbl; 491da177e4SLinus Torvalds 501da177e4SLinus Torvalds void *sysctl_table; 511da177e4SLinus Torvalds 521da177e4SLinus Torvalds int dead; 531da177e4SLinus Torvalds atomic_t refcnt; 541da177e4SLinus Torvalds struct rcu_head rcu_head; 551da177e4SLinus Torvalds 561da177e4SLinus Torvalds int base_reachable_time; 571da177e4SLinus Torvalds int retrans_time; 581da177e4SLinus Torvalds int gc_staletime; 591da177e4SLinus Torvalds int reachable_time; 601da177e4SLinus Torvalds int delay_probe_time; 611da177e4SLinus Torvalds 621da177e4SLinus Torvalds int queue_len; 631da177e4SLinus Torvalds int ucast_probes; 641da177e4SLinus Torvalds int app_probes; 651da177e4SLinus Torvalds int mcast_probes; 661da177e4SLinus Torvalds int anycast_delay; 671da177e4SLinus Torvalds int proxy_delay; 681da177e4SLinus Torvalds int proxy_qlen; 691da177e4SLinus Torvalds int locktime; 701da177e4SLinus Torvalds }; 711da177e4SLinus Torvalds 72fd2c3ef7SEric Dumazet struct neigh_statistics { 731da177e4SLinus Torvalds unsigned long allocs; /* number of allocated neighs */ 741da177e4SLinus Torvalds unsigned long destroys; /* number of destroyed neighs */ 751da177e4SLinus Torvalds unsigned long hash_grows; /* number of hash resizes */ 761da177e4SLinus Torvalds 779a6d276eSNeil Horman unsigned long res_failed; /* number of failed resolutions */ 781da177e4SLinus Torvalds 791da177e4SLinus Torvalds unsigned long lookups; /* number of lookups */ 801da177e4SLinus Torvalds unsigned long hits; /* number of hits (among lookups) */ 811da177e4SLinus Torvalds 821da177e4SLinus Torvalds unsigned long rcv_probes_mcast; /* number of received mcast ipv6 */ 831da177e4SLinus Torvalds unsigned long rcv_probes_ucast; /* number of received ucast ipv6 */ 841da177e4SLinus Torvalds 851da177e4SLinus Torvalds unsigned long periodic_gc_runs; /* number of periodic GC runs */ 861da177e4SLinus Torvalds unsigned long forced_gc_runs; /* number of forced GC runs */ 879a6d276eSNeil Horman 889a6d276eSNeil Horman unsigned long unres_discards; /* number of unresolved drops */ 891da177e4SLinus Torvalds }; 901da177e4SLinus Torvalds 911da177e4SLinus Torvalds #define NEIGH_CACHE_STAT_INC(tbl, field) \ 921da177e4SLinus Torvalds do { \ 931da177e4SLinus Torvalds preempt_disable(); \ 941da177e4SLinus Torvalds (per_cpu_ptr((tbl)->stats, smp_processor_id())->field)++; \ 951da177e4SLinus Torvalds preempt_enable(); \ 961da177e4SLinus Torvalds } while (0) 971da177e4SLinus Torvalds 98fd2c3ef7SEric Dumazet struct neighbour { 991da177e4SLinus Torvalds struct neighbour *next; 1001da177e4SLinus Torvalds struct neigh_table *tbl; 1011da177e4SLinus Torvalds struct neigh_parms *parms; 1021da177e4SLinus Torvalds struct net_device *dev; 1031da177e4SLinus Torvalds unsigned long used; 1041da177e4SLinus Torvalds unsigned long confirmed; 1051da177e4SLinus Torvalds unsigned long updated; 1061da177e4SLinus Torvalds __u8 flags; 1071da177e4SLinus Torvalds __u8 nud_state; 1081da177e4SLinus Torvalds __u8 type; 1091da177e4SLinus Torvalds __u8 dead; 1101da177e4SLinus Torvalds atomic_t probes; 1111da177e4SLinus Torvalds rwlock_t lock; 112d924424aSStephen Hemminger unsigned char ha[ALIGN(MAX_ADDR_LEN, sizeof(unsigned long))]; 1131da177e4SLinus Torvalds struct hh_cache *hh; 1141da177e4SLinus Torvalds atomic_t refcnt; 1151da177e4SLinus Torvalds int (*output)(struct sk_buff *skb); 1161da177e4SLinus Torvalds struct sk_buff_head arp_queue; 1171da177e4SLinus Torvalds struct timer_list timer; 11889d69d2bSStephen Hemminger const struct neigh_ops *ops; 1191da177e4SLinus Torvalds u8 primary_key[0]; 1201da177e4SLinus Torvalds }; 1211da177e4SLinus Torvalds 122fd2c3ef7SEric Dumazet struct neigh_ops { 1231da177e4SLinus Torvalds int family; 1241da177e4SLinus Torvalds void (*solicit)(struct neighbour *, struct sk_buff*); 1251da177e4SLinus Torvalds void (*error_report)(struct neighbour *, struct sk_buff*); 1261da177e4SLinus Torvalds int (*output)(struct sk_buff*); 1271da177e4SLinus Torvalds int (*connected_output)(struct sk_buff*); 1281da177e4SLinus Torvalds int (*hh_output)(struct sk_buff*); 1291da177e4SLinus Torvalds int (*queue_xmit)(struct sk_buff*); 1301da177e4SLinus Torvalds }; 1311da177e4SLinus Torvalds 132fd2c3ef7SEric Dumazet struct pneigh_entry { 1331da177e4SLinus Torvalds struct pneigh_entry *next; 13457da52c1SYOSHIFUJI Hideaki #ifdef CONFIG_NET_NS 135426b5303SEric W. Biederman struct net *net; 13657da52c1SYOSHIFUJI Hideaki #endif 1371da177e4SLinus Torvalds struct net_device *dev; 13862dd9318SVille Nuorvala u8 flags; 1391da177e4SLinus Torvalds u8 key[0]; 1401da177e4SLinus Torvalds }; 1411da177e4SLinus Torvalds 1421da177e4SLinus Torvalds /* 1431da177e4SLinus Torvalds * neighbour table manipulation 1441da177e4SLinus Torvalds */ 1451da177e4SLinus Torvalds 1461da177e4SLinus Torvalds 147fd2c3ef7SEric Dumazet struct neigh_table { 1481da177e4SLinus Torvalds struct neigh_table *next; 1491da177e4SLinus Torvalds int family; 1501da177e4SLinus Torvalds int entry_size; 1511da177e4SLinus Torvalds int key_len; 1521da177e4SLinus Torvalds __u32 (*hash)(const void *pkey, const struct net_device *); 1531da177e4SLinus Torvalds int (*constructor)(struct neighbour *); 1541da177e4SLinus Torvalds int (*pconstructor)(struct pneigh_entry *); 1551da177e4SLinus Torvalds void (*pdestructor)(struct pneigh_entry *); 1561da177e4SLinus Torvalds void (*proxy_redo)(struct sk_buff *skb); 1571da177e4SLinus Torvalds char *id; 1581da177e4SLinus Torvalds struct neigh_parms parms; 1591da177e4SLinus Torvalds /* HACK. gc_* shoul follow parms without a gap! */ 1601da177e4SLinus Torvalds int gc_interval; 1611da177e4SLinus Torvalds int gc_thresh1; 1621da177e4SLinus Torvalds int gc_thresh2; 1631da177e4SLinus Torvalds int gc_thresh3; 1641da177e4SLinus Torvalds unsigned long last_flush; 165e4c4e448SEric Dumazet struct delayed_work gc_work; 1661da177e4SLinus Torvalds struct timer_list proxy_timer; 1671da177e4SLinus Torvalds struct sk_buff_head proxy_queue; 1681da177e4SLinus Torvalds atomic_t entries; 1691da177e4SLinus Torvalds rwlock_t lock; 1701da177e4SLinus Torvalds unsigned long last_rand; 171e18b890bSChristoph Lameter struct kmem_cache *kmem_cachep; 1721da177e4SLinus Torvalds struct neigh_statistics *stats; 1731da177e4SLinus Torvalds struct neighbour **hash_buckets; 1741da177e4SLinus Torvalds unsigned int hash_mask; 1751da177e4SLinus Torvalds __u32 hash_rnd; 1761da177e4SLinus Torvalds struct pneigh_entry **phash_buckets; 1771da177e4SLinus Torvalds }; 1781da177e4SLinus Torvalds 1791da177e4SLinus Torvalds /* flags for neigh_update() */ 1801da177e4SLinus Torvalds #define NEIGH_UPDATE_F_OVERRIDE 0x00000001 1811da177e4SLinus Torvalds #define NEIGH_UPDATE_F_WEAK_OVERRIDE 0x00000002 1821da177e4SLinus Torvalds #define NEIGH_UPDATE_F_OVERRIDE_ISROUTER 0x00000004 1831da177e4SLinus Torvalds #define NEIGH_UPDATE_F_ISROUTER 0x40000000 1841da177e4SLinus Torvalds #define NEIGH_UPDATE_F_ADMIN 0x80000000 1851da177e4SLinus Torvalds 1861da177e4SLinus Torvalds extern void neigh_table_init(struct neigh_table *tbl); 187bd89efc5SSimon Kelley extern void neigh_table_init_no_netlink(struct neigh_table *tbl); 1881da177e4SLinus Torvalds extern int neigh_table_clear(struct neigh_table *tbl); 1891da177e4SLinus Torvalds extern struct neighbour * neigh_lookup(struct neigh_table *tbl, 1901da177e4SLinus Torvalds const void *pkey, 1911da177e4SLinus Torvalds struct net_device *dev); 1921da177e4SLinus Torvalds extern struct neighbour * neigh_lookup_nodev(struct neigh_table *tbl, 193426b5303SEric W. Biederman struct net *net, 1941da177e4SLinus Torvalds const void *pkey); 1951da177e4SLinus Torvalds extern struct neighbour * neigh_create(struct neigh_table *tbl, 1961da177e4SLinus Torvalds const void *pkey, 1971da177e4SLinus Torvalds struct net_device *dev); 1981da177e4SLinus Torvalds extern void neigh_destroy(struct neighbour *neigh); 1991da177e4SLinus Torvalds extern int __neigh_event_send(struct neighbour *neigh, struct sk_buff *skb); 2001da177e4SLinus Torvalds extern int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new, 2011da177e4SLinus Torvalds u32 flags); 2021da177e4SLinus Torvalds extern void neigh_changeaddr(struct neigh_table *tbl, struct net_device *dev); 2031da177e4SLinus Torvalds extern int neigh_ifdown(struct neigh_table *tbl, struct net_device *dev); 2041da177e4SLinus Torvalds extern int neigh_resolve_output(struct sk_buff *skb); 2051da177e4SLinus Torvalds extern int neigh_connected_output(struct sk_buff *skb); 2061da177e4SLinus Torvalds extern int neigh_compat_output(struct sk_buff *skb); 2071da177e4SLinus Torvalds extern struct neighbour *neigh_event_ns(struct neigh_table *tbl, 2081da177e4SLinus Torvalds u8 *lladdr, void *saddr, 2091da177e4SLinus Torvalds struct net_device *dev); 2101da177e4SLinus Torvalds 2111da177e4SLinus Torvalds extern struct neigh_parms *neigh_parms_alloc(struct net_device *dev, struct neigh_table *tbl); 2121da177e4SLinus Torvalds extern void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms); 21357da52c1SYOSHIFUJI Hideaki 21457da52c1SYOSHIFUJI Hideaki static inline 21557da52c1SYOSHIFUJI Hideaki struct net *neigh_parms_net(const struct neigh_parms *parms) 21657da52c1SYOSHIFUJI Hideaki { 217e42ea986SEric Dumazet return read_pnet(&parms->net); 21857da52c1SYOSHIFUJI Hideaki } 21957da52c1SYOSHIFUJI Hideaki 2201da177e4SLinus Torvalds extern unsigned long neigh_rand_reach_time(unsigned long base); 2211da177e4SLinus Torvalds 2221da177e4SLinus Torvalds extern void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p, 2231da177e4SLinus Torvalds struct sk_buff *skb); 224426b5303SEric W. Biederman extern struct pneigh_entry *pneigh_lookup(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev, int creat); 225fa86d322SPavel Emelyanov extern struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl, 226fa86d322SPavel Emelyanov struct net *net, 227fa86d322SPavel Emelyanov const void *key, 228fa86d322SPavel Emelyanov struct net_device *dev); 229426b5303SEric W. Biederman extern int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev); 2301da177e4SLinus Torvalds 23157da52c1SYOSHIFUJI Hideaki static inline 23257da52c1SYOSHIFUJI Hideaki struct net *pneigh_net(const struct pneigh_entry *pneigh) 23357da52c1SYOSHIFUJI Hideaki { 234e42ea986SEric Dumazet return read_pnet(&pneigh->net); 23557da52c1SYOSHIFUJI Hideaki } 23657da52c1SYOSHIFUJI Hideaki 2371da177e4SLinus Torvalds extern void neigh_app_ns(struct neighbour *n); 2381da177e4SLinus Torvalds extern void neigh_for_each(struct neigh_table *tbl, void (*cb)(struct neighbour *, void *), void *cookie); 2391da177e4SLinus Torvalds extern void __neigh_for_each_release(struct neigh_table *tbl, int (*cb)(struct neighbour *)); 2401da177e4SLinus Torvalds extern void pneigh_for_each(struct neigh_table *tbl, void (*cb)(struct pneigh_entry *)); 2411da177e4SLinus Torvalds 2421da177e4SLinus Torvalds struct neigh_seq_state { 24342508461SDenis V. Lunev struct seq_net_private p; 2441da177e4SLinus Torvalds struct neigh_table *tbl; 2451da177e4SLinus Torvalds void *(*neigh_sub_iter)(struct neigh_seq_state *state, 2461da177e4SLinus Torvalds struct neighbour *n, loff_t *pos); 2471da177e4SLinus Torvalds unsigned int bucket; 2481da177e4SLinus Torvalds unsigned int flags; 2491da177e4SLinus Torvalds #define NEIGH_SEQ_NEIGH_ONLY 0x00000001 2501da177e4SLinus Torvalds #define NEIGH_SEQ_IS_PNEIGH 0x00000002 2511da177e4SLinus Torvalds #define NEIGH_SEQ_SKIP_NOARP 0x00000004 2521da177e4SLinus Torvalds }; 2531da177e4SLinus Torvalds extern void *neigh_seq_start(struct seq_file *, loff_t *, struct neigh_table *, unsigned int); 2541da177e4SLinus Torvalds extern void *neigh_seq_next(struct seq_file *, void *, loff_t *); 2551da177e4SLinus Torvalds extern void neigh_seq_stop(struct seq_file *, void *); 2561da177e4SLinus Torvalds 2571da177e4SLinus Torvalds extern int neigh_sysctl_register(struct net_device *dev, 2581da177e4SLinus Torvalds struct neigh_parms *p, 2591da177e4SLinus Torvalds int p_id, int pdev_id, 2601da177e4SLinus Torvalds char *p_name, 2611da177e4SLinus Torvalds proc_handler *proc_handler, 2621da177e4SLinus Torvalds ctl_handler *strategy); 2631da177e4SLinus Torvalds extern void neigh_sysctl_unregister(struct neigh_parms *p); 2641da177e4SLinus Torvalds 2651da177e4SLinus Torvalds static inline void __neigh_parms_put(struct neigh_parms *parms) 2661da177e4SLinus Torvalds { 2671da177e4SLinus Torvalds atomic_dec(&parms->refcnt); 2681da177e4SLinus Torvalds } 2691da177e4SLinus Torvalds 2701da177e4SLinus Torvalds static inline struct neigh_parms *neigh_parms_clone(struct neigh_parms *parms) 2711da177e4SLinus Torvalds { 2721da177e4SLinus Torvalds atomic_inc(&parms->refcnt); 2731da177e4SLinus Torvalds return parms; 2741da177e4SLinus Torvalds } 2751da177e4SLinus Torvalds 2761da177e4SLinus Torvalds /* 2771da177e4SLinus Torvalds * Neighbour references 2781da177e4SLinus Torvalds */ 2791da177e4SLinus Torvalds 2801da177e4SLinus Torvalds static inline void neigh_release(struct neighbour *neigh) 2811da177e4SLinus Torvalds { 2821da177e4SLinus Torvalds if (atomic_dec_and_test(&neigh->refcnt)) 2831da177e4SLinus Torvalds neigh_destroy(neigh); 2841da177e4SLinus Torvalds } 2851da177e4SLinus Torvalds 2861da177e4SLinus Torvalds static inline struct neighbour * neigh_clone(struct neighbour *neigh) 2871da177e4SLinus Torvalds { 2881da177e4SLinus Torvalds if (neigh) 2891da177e4SLinus Torvalds atomic_inc(&neigh->refcnt); 2901da177e4SLinus Torvalds return neigh; 2911da177e4SLinus Torvalds } 2921da177e4SLinus Torvalds 2931da177e4SLinus Torvalds #define neigh_hold(n) atomic_inc(&(n)->refcnt) 2941da177e4SLinus Torvalds 2951da177e4SLinus Torvalds static inline void neigh_confirm(struct neighbour *neigh) 2961da177e4SLinus Torvalds { 2971da177e4SLinus Torvalds if (neigh) 2981da177e4SLinus Torvalds neigh->confirmed = jiffies; 2991da177e4SLinus Torvalds } 3001da177e4SLinus Torvalds 3011da177e4SLinus Torvalds static inline int neigh_event_send(struct neighbour *neigh, struct sk_buff *skb) 3021da177e4SLinus Torvalds { 3031da177e4SLinus Torvalds neigh->used = jiffies; 3041da177e4SLinus Torvalds if (!(neigh->nud_state&(NUD_CONNECTED|NUD_DELAY|NUD_PROBE))) 3051da177e4SLinus Torvalds return __neigh_event_send(neigh, skb); 3061da177e4SLinus Torvalds return 0; 3071da177e4SLinus Torvalds } 3081da177e4SLinus Torvalds 3093644f0ceSStephen Hemminger static inline int neigh_hh_output(struct hh_cache *hh, struct sk_buff *skb) 3103644f0ceSStephen Hemminger { 3113644f0ceSStephen Hemminger unsigned seq; 3123644f0ceSStephen Hemminger int hh_len; 3133644f0ceSStephen Hemminger 3143644f0ceSStephen Hemminger do { 3153644f0ceSStephen Hemminger int hh_alen; 3163644f0ceSStephen Hemminger 3173644f0ceSStephen Hemminger seq = read_seqbegin(&hh->hh_lock); 3183644f0ceSStephen Hemminger hh_len = hh->hh_len; 3193644f0ceSStephen Hemminger hh_alen = HH_DATA_ALIGN(hh_len); 3203644f0ceSStephen Hemminger memcpy(skb->data - hh_alen, hh->hh_data, hh_alen); 3213644f0ceSStephen Hemminger } while (read_seqretry(&hh->hh_lock, seq)); 3223644f0ceSStephen Hemminger 3233644f0ceSStephen Hemminger skb_push(skb, hh_len); 3243644f0ceSStephen Hemminger return hh->hh_output(skb); 3253644f0ceSStephen Hemminger } 3263644f0ceSStephen Hemminger 3271da177e4SLinus Torvalds static inline struct neighbour * 3281da177e4SLinus Torvalds __neigh_lookup(struct neigh_table *tbl, const void *pkey, struct net_device *dev, int creat) 3291da177e4SLinus Torvalds { 3301da177e4SLinus Torvalds struct neighbour *n = neigh_lookup(tbl, pkey, dev); 3311da177e4SLinus Torvalds 3321da177e4SLinus Torvalds if (n || !creat) 3331da177e4SLinus Torvalds return n; 3341da177e4SLinus Torvalds 3351da177e4SLinus Torvalds n = neigh_create(tbl, pkey, dev); 3361da177e4SLinus Torvalds return IS_ERR(n) ? NULL : n; 3371da177e4SLinus Torvalds } 3381da177e4SLinus Torvalds 3391da177e4SLinus Torvalds static inline struct neighbour * 3401da177e4SLinus Torvalds __neigh_lookup_errno(struct neigh_table *tbl, const void *pkey, 3411da177e4SLinus Torvalds struct net_device *dev) 3421da177e4SLinus Torvalds { 3431da177e4SLinus Torvalds struct neighbour *n = neigh_lookup(tbl, pkey, dev); 3441da177e4SLinus Torvalds 3451da177e4SLinus Torvalds if (n) 3461da177e4SLinus Torvalds return n; 3471da177e4SLinus Torvalds 3481da177e4SLinus Torvalds return neigh_create(tbl, pkey, dev); 3491da177e4SLinus Torvalds } 3501da177e4SLinus Torvalds 351a61bbcf2SPatrick McHardy struct neighbour_cb { 352a61bbcf2SPatrick McHardy unsigned long sched_next; 353a61bbcf2SPatrick McHardy unsigned int flags; 354a61bbcf2SPatrick McHardy }; 355a61bbcf2SPatrick McHardy 356a61bbcf2SPatrick McHardy #define LOCALLY_ENQUEUED 0x1 357a61bbcf2SPatrick McHardy 358a61bbcf2SPatrick McHardy #define NEIGH_CB(skb) ((struct neighbour_cb *)(skb)->cb) 3591da177e4SLinus Torvalds 3601da177e4SLinus Torvalds #endif 361