| lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame] | 1 | /* |
| 2 | * INETPEER - A storage for permanent information about peers |
| 3 | * |
| 4 | * Authors: Andrey V. Savochkin <saw@msu.ru> |
| 5 | */ |
| 6 | |
| 7 | #ifndef _NET_INETPEER_H |
| 8 | #define _NET_INETPEER_H |
| 9 | |
| 10 | #include <linux/types.h> |
| 11 | #include <linux/init.h> |
| 12 | #include <linux/jiffies.h> |
| 13 | #include <linux/spinlock.h> |
| 14 | #include <linux/rtnetlink.h> |
| 15 | #include <net/ipv6.h> |
| 16 | #include <linux/atomic.h> |
| 17 | |
| 18 | struct inetpeer_addr_base { |
| 19 | union { |
| 20 | __be32 a4; |
| 21 | __be32 a6[4]; |
| 22 | }; |
| 23 | }; |
| 24 | |
| 25 | struct inetpeer_addr { |
| 26 | struct inetpeer_addr_base addr; |
| 27 | __u16 family; |
| 28 | }; |
| 29 | |
| 30 | struct inet_peer { |
| 31 | /* group together avl_left,avl_right,v4daddr to speedup lookups */ |
| 32 | struct inet_peer __rcu *avl_left, *avl_right; |
| 33 | struct inetpeer_addr daddr; |
| 34 | __u32 avl_height; |
| 35 | |
| 36 | u32 metrics[RTAX_MAX]; |
| 37 | u32 rate_tokens; /* rate limiting for ICMP */ |
| 38 | unsigned long rate_last; |
| 39 | unsigned long pmtu_expires; |
| 40 | u32 pmtu_orig; |
| 41 | u32 pmtu_learned; |
| 42 | struct inetpeer_addr_base redirect_learned; |
| 43 | union { |
| 44 | struct list_head gc_list; |
| 45 | struct rcu_head gc_rcu; |
| 46 | }; |
| 47 | /* |
| 48 | * Once inet_peer is queued for deletion (refcnt == -1), following fields |
| 49 | * are not available: rid, tcp_ts, tcp_ts_stamp |
| 50 | * We can share memory with rcu_head to help keep inet_peer small. |
| 51 | */ |
| 52 | union { |
| 53 | struct { |
| 54 | atomic_t rid; /* Frag reception counter */ |
| 55 | __u32 tcp_ts; |
| 56 | __u32 tcp_ts_stamp; |
| 57 | }; |
| 58 | struct rcu_head rcu; |
| 59 | struct inet_peer *gc_next; |
| 60 | }; |
| 61 | |
| 62 | /* following fields might be frequently dirtied */ |
| 63 | __u32 dtime; /* the time of last use of not referenced entries */ |
| 64 | atomic_t refcnt; |
| 65 | }; |
| 66 | |
| 67 | void inet_initpeers(void) __init; |
| 68 | |
| 69 | #define INETPEER_METRICS_NEW (~(u32) 0) |
| 70 | |
| 71 | static inline bool inet_metrics_new(const struct inet_peer *p) |
| 72 | { |
| 73 | return p->metrics[RTAX_LOCK-1] == INETPEER_METRICS_NEW; |
| 74 | } |
| 75 | |
| 76 | /* can be called with or without local BH being disabled */ |
| 77 | struct inet_peer *inet_getpeer(const struct inetpeer_addr *daddr, int create); |
| 78 | |
| 79 | static inline struct inet_peer *inet_getpeer_v4(__be32 v4daddr, int create) |
| 80 | { |
| 81 | struct inetpeer_addr daddr; |
| 82 | |
| 83 | daddr.addr.a4 = v4daddr; |
| 84 | daddr.family = AF_INET; |
| 85 | return inet_getpeer(&daddr, create); |
| 86 | } |
| 87 | |
| 88 | static inline struct inet_peer *inet_getpeer_v6(const struct in6_addr *v6daddr, int create) |
| 89 | { |
| 90 | struct inetpeer_addr daddr; |
| 91 | |
| 92 | *(struct in6_addr *)daddr.addr.a6 = *v6daddr; |
| 93 | daddr.family = AF_INET6; |
| 94 | return inet_getpeer(&daddr, create); |
| 95 | } |
| 96 | |
| 97 | /* can be called from BH context or outside */ |
| 98 | extern void inet_putpeer(struct inet_peer *p); |
| 99 | extern bool inet_peer_xrlim_allow(struct inet_peer *peer, int timeout); |
| 100 | |
| 101 | extern void inetpeer_invalidate_tree(int family); |
| 102 | |
| 103 | /* |
| 104 | * temporary check to make sure we dont access rid, tcp_ts, |
| 105 | * tcp_ts_stamp if no refcount is taken on inet_peer |
| 106 | */ |
| 107 | static inline void inet_peer_refcheck(const struct inet_peer *p) |
| 108 | { |
| 109 | WARN_ON_ONCE(atomic_read(&p->refcnt) <= 0); |
| 110 | } |
| 111 | |
| 112 | #endif /* _NET_INETPEER_H */ |