12e6599cbSArnaldo Carvalho de Melo /* 22e6599cbSArnaldo Carvalho de Melo * NET Generic infrastructure for Network protocols. 32e6599cbSArnaldo Carvalho de Melo * 42e6599cbSArnaldo Carvalho de Melo * Definitions for request_sock 52e6599cbSArnaldo Carvalho de Melo * 62e6599cbSArnaldo Carvalho de Melo * Authors: Arnaldo Carvalho de Melo <acme@conectiva.com.br> 72e6599cbSArnaldo Carvalho de Melo * 82e6599cbSArnaldo Carvalho de Melo * From code originally in include/net/tcp.h 92e6599cbSArnaldo Carvalho de Melo * 102e6599cbSArnaldo Carvalho de Melo * This program is free software; you can redistribute it and/or 112e6599cbSArnaldo Carvalho de Melo * modify it under the terms of the GNU General Public License 122e6599cbSArnaldo Carvalho de Melo * as published by the Free Software Foundation; either version 132e6599cbSArnaldo Carvalho de Melo * 2 of the License, or (at your option) any later version. 142e6599cbSArnaldo Carvalho de Melo */ 152e6599cbSArnaldo Carvalho de Melo #ifndef _REQUEST_SOCK_H 162e6599cbSArnaldo Carvalho de Melo #define _REQUEST_SOCK_H 172e6599cbSArnaldo Carvalho de Melo 182e6599cbSArnaldo Carvalho de Melo #include <linux/slab.h> 190e87506fSArnaldo Carvalho de Melo #include <linux/spinlock.h> 202e6599cbSArnaldo Carvalho de Melo #include <linux/types.h> 21547b792cSIlpo Järvinen #include <linux/bug.h> 220e87506fSArnaldo Carvalho de Melo 232e6599cbSArnaldo Carvalho de Melo #include <net/sock.h> 242e6599cbSArnaldo Carvalho de Melo 2560236fddSArnaldo Carvalho de Melo struct request_sock; 262e6599cbSArnaldo Carvalho de Melo struct sk_buff; 272e6599cbSArnaldo Carvalho de Melo struct dst_entry; 282e6599cbSArnaldo Carvalho de Melo struct proto; 292e6599cbSArnaldo Carvalho de Melo 3060236fddSArnaldo Carvalho de Melo struct request_sock_ops { 312e6599cbSArnaldo Carvalho de Melo int family; 322e6599cbSArnaldo Carvalho de Melo int obj_size; 33e18b890bSChristoph Lameter struct kmem_cache *slab; 342e6599cbSArnaldo Carvalho de Melo int (*rtx_syn_ack)(struct sock *sk, 35fd80eb94SDenis V. Lunev struct request_sock *req); 366edafaafSGui Jianfeng void (*send_ack)(struct sock *sk, struct sk_buff *skb, 3760236fddSArnaldo Carvalho de Melo struct request_sock *req); 38cfb6eeb4SYOSHIFUJI Hideaki void (*send_reset)(struct sock *sk, 39cfb6eeb4SYOSHIFUJI Hideaki struct sk_buff *skb); 4060236fddSArnaldo Carvalho de Melo void (*destructor)(struct request_sock *req); 412e6599cbSArnaldo Carvalho de Melo }; 422e6599cbSArnaldo Carvalho de Melo 4360236fddSArnaldo Carvalho de Melo /* struct request_sock - mini sock to represent a connection request 442e6599cbSArnaldo Carvalho de Melo */ 4560236fddSArnaldo Carvalho de Melo struct request_sock { 4660236fddSArnaldo Carvalho de Melo struct request_sock *dl_next; /* Must be first member! */ 472e6599cbSArnaldo Carvalho de Melo u16 mss; 482e6599cbSArnaldo Carvalho de Melo u8 retrans; 494dfc2817SFlorian Westphal u8 cookie_ts; /* syncookie: encode tcpopts in timestamp */ 502e6599cbSArnaldo Carvalho de Melo /* The following two fields can be easily recomputed I think -AK */ 512e6599cbSArnaldo Carvalho de Melo u32 window_clamp; /* window clamp at creation time */ 522e6599cbSArnaldo Carvalho de Melo u32 rcv_wnd; /* rcv_wnd offered first time */ 532e6599cbSArnaldo Carvalho de Melo u32 ts_recent; 542e6599cbSArnaldo Carvalho de Melo unsigned long expires; 5572a3effaSEric Dumazet const struct request_sock_ops *rsk_ops; 562e6599cbSArnaldo Carvalho de Melo struct sock *sk; 574237c75cSVenkat Yekkirala u32 secid; 586b877699SVenkat Yekkirala u32 peer_secid; 592e6599cbSArnaldo Carvalho de Melo }; 602e6599cbSArnaldo Carvalho de Melo 6172a3effaSEric Dumazet static inline struct request_sock *reqsk_alloc(const struct request_sock_ops *ops) 622e6599cbSArnaldo Carvalho de Melo { 6354e6ecb2SChristoph Lameter struct request_sock *req = kmem_cache_alloc(ops->slab, GFP_ATOMIC); 642e6599cbSArnaldo Carvalho de Melo 652e6599cbSArnaldo Carvalho de Melo if (req != NULL) 6660236fddSArnaldo Carvalho de Melo req->rsk_ops = ops; 672e6599cbSArnaldo Carvalho de Melo 682e6599cbSArnaldo Carvalho de Melo return req; 692e6599cbSArnaldo Carvalho de Melo } 702e6599cbSArnaldo Carvalho de Melo 7160236fddSArnaldo Carvalho de Melo static inline void __reqsk_free(struct request_sock *req) 722e6599cbSArnaldo Carvalho de Melo { 7360236fddSArnaldo Carvalho de Melo kmem_cache_free(req->rsk_ops->slab, req); 742e6599cbSArnaldo Carvalho de Melo } 752e6599cbSArnaldo Carvalho de Melo 7660236fddSArnaldo Carvalho de Melo static inline void reqsk_free(struct request_sock *req) 772e6599cbSArnaldo Carvalho de Melo { 7860236fddSArnaldo Carvalho de Melo req->rsk_ops->destructor(req); 7960236fddSArnaldo Carvalho de Melo __reqsk_free(req); 802e6599cbSArnaldo Carvalho de Melo } 812e6599cbSArnaldo Carvalho de Melo 820e87506fSArnaldo Carvalho de Melo extern int sysctl_max_syn_backlog; 830e87506fSArnaldo Carvalho de Melo 842ad69c55SArnaldo Carvalho de Melo /** struct listen_sock - listen state 850e87506fSArnaldo Carvalho de Melo * 860e87506fSArnaldo Carvalho de Melo * @max_qlen_log - log_2 of maximal queued SYNs/REQUESTs 870e87506fSArnaldo Carvalho de Melo */ 882ad69c55SArnaldo Carvalho de Melo struct listen_sock { 890e87506fSArnaldo Carvalho de Melo u8 max_qlen_log; 900e87506fSArnaldo Carvalho de Melo /* 3 bytes hole, try to use */ 910e87506fSArnaldo Carvalho de Melo int qlen; 920e87506fSArnaldo Carvalho de Melo int qlen_young; 930e87506fSArnaldo Carvalho de Melo int clock_hand; 940e87506fSArnaldo Carvalho de Melo u32 hash_rnd; 9583e3609eSArnaldo Carvalho de Melo u32 nr_table_entries; 960e87506fSArnaldo Carvalho de Melo struct request_sock *syn_table[0]; 970e87506fSArnaldo Carvalho de Melo }; 980e87506fSArnaldo Carvalho de Melo 990e87506fSArnaldo Carvalho de Melo /** struct request_sock_queue - queue of request_socks 1000e87506fSArnaldo Carvalho de Melo * 1010e87506fSArnaldo Carvalho de Melo * @rskq_accept_head - FIFO head of established children 1020e87506fSArnaldo Carvalho de Melo * @rskq_accept_tail - FIFO tail of established children 103295f7324SArnaldo Carvalho de Melo * @rskq_defer_accept - User waits for some data after accept() 1040e87506fSArnaldo Carvalho de Melo * @syn_wait_lock - serializer 1050e87506fSArnaldo Carvalho de Melo * 1060e87506fSArnaldo Carvalho de Melo * %syn_wait_lock is necessary only to avoid proc interface having to grab the main 1070e87506fSArnaldo Carvalho de Melo * lock sock while browsing the listening hash (otherwise it's deadlock prone). 1080e87506fSArnaldo Carvalho de Melo * 1090e87506fSArnaldo Carvalho de Melo * This lock is acquired in read mode only from listening_get_next() seq_file 1100e87506fSArnaldo Carvalho de Melo * op and it's acquired in write mode _only_ from code that is actively 1110e87506fSArnaldo Carvalho de Melo * changing rskq_accept_head. All readers that are holding the master sock lock 1120e87506fSArnaldo Carvalho de Melo * don't need to grab this lock in read mode too as rskq_accept_head. writes 1130e87506fSArnaldo Carvalho de Melo * are always protected from the main sock lock. 1140e87506fSArnaldo Carvalho de Melo */ 1150e87506fSArnaldo Carvalho de Melo struct request_sock_queue { 1160e87506fSArnaldo Carvalho de Melo struct request_sock *rskq_accept_head; 1170e87506fSArnaldo Carvalho de Melo struct request_sock *rskq_accept_tail; 1180e87506fSArnaldo Carvalho de Melo rwlock_t syn_wait_lock; 119ec0a1966SDavid S. Miller u8 rskq_defer_accept; 120ec0a1966SDavid S. Miller /* 3 bytes hole, try to pack */ 1212ad69c55SArnaldo Carvalho de Melo struct listen_sock *listen_opt; 1220e87506fSArnaldo Carvalho de Melo }; 1230e87506fSArnaldo Carvalho de Melo 1240e87506fSArnaldo Carvalho de Melo extern int reqsk_queue_alloc(struct request_sock_queue *queue, 12572a3effaSEric Dumazet unsigned int nr_table_entries); 1260e87506fSArnaldo Carvalho de Melo 127dab6ba36SPavel Emelyanov extern void __reqsk_queue_destroy(struct request_sock_queue *queue); 12883e3609eSArnaldo Carvalho de Melo extern void reqsk_queue_destroy(struct request_sock_queue *queue); 12983e3609eSArnaldo Carvalho de Melo 1300e87506fSArnaldo Carvalho de Melo static inline struct request_sock * 1310e87506fSArnaldo Carvalho de Melo reqsk_queue_yank_acceptq(struct request_sock_queue *queue) 1320e87506fSArnaldo Carvalho de Melo { 1330e87506fSArnaldo Carvalho de Melo struct request_sock *req = queue->rskq_accept_head; 1340e87506fSArnaldo Carvalho de Melo 1353eb4801dSNorbert Kiesel queue->rskq_accept_head = NULL; 1360e87506fSArnaldo Carvalho de Melo return req; 1370e87506fSArnaldo Carvalho de Melo } 1380e87506fSArnaldo Carvalho de Melo 1390e87506fSArnaldo Carvalho de Melo static inline int reqsk_queue_empty(struct request_sock_queue *queue) 1400e87506fSArnaldo Carvalho de Melo { 1410e87506fSArnaldo Carvalho de Melo return queue->rskq_accept_head == NULL; 1420e87506fSArnaldo Carvalho de Melo } 1430e87506fSArnaldo Carvalho de Melo 1440e87506fSArnaldo Carvalho de Melo static inline void reqsk_queue_unlink(struct request_sock_queue *queue, 1450e87506fSArnaldo Carvalho de Melo struct request_sock *req, 1460e87506fSArnaldo Carvalho de Melo struct request_sock **prev_req) 1470e87506fSArnaldo Carvalho de Melo { 1480e87506fSArnaldo Carvalho de Melo write_lock(&queue->syn_wait_lock); 1490e87506fSArnaldo Carvalho de Melo *prev_req = req->dl_next; 1500e87506fSArnaldo Carvalho de Melo write_unlock(&queue->syn_wait_lock); 1510e87506fSArnaldo Carvalho de Melo } 1520e87506fSArnaldo Carvalho de Melo 1530e87506fSArnaldo Carvalho de Melo static inline void reqsk_queue_add(struct request_sock_queue *queue, 1540e87506fSArnaldo Carvalho de Melo struct request_sock *req, 1550e87506fSArnaldo Carvalho de Melo struct sock *parent, 1560e87506fSArnaldo Carvalho de Melo struct sock *child) 1570e87506fSArnaldo Carvalho de Melo { 1580e87506fSArnaldo Carvalho de Melo req->sk = child; 1590e87506fSArnaldo Carvalho de Melo sk_acceptq_added(parent); 1600e87506fSArnaldo Carvalho de Melo 1610e87506fSArnaldo Carvalho de Melo if (queue->rskq_accept_head == NULL) 1620e87506fSArnaldo Carvalho de Melo queue->rskq_accept_head = req; 1630e87506fSArnaldo Carvalho de Melo else 1640e87506fSArnaldo Carvalho de Melo queue->rskq_accept_tail->dl_next = req; 1650e87506fSArnaldo Carvalho de Melo 1660e87506fSArnaldo Carvalho de Melo queue->rskq_accept_tail = req; 1670e87506fSArnaldo Carvalho de Melo req->dl_next = NULL; 1680e87506fSArnaldo Carvalho de Melo } 1690e87506fSArnaldo Carvalho de Melo 1700e87506fSArnaldo Carvalho de Melo static inline struct request_sock *reqsk_queue_remove(struct request_sock_queue *queue) 1710e87506fSArnaldo Carvalho de Melo { 1720e87506fSArnaldo Carvalho de Melo struct request_sock *req = queue->rskq_accept_head; 1730e87506fSArnaldo Carvalho de Melo 174547b792cSIlpo Järvinen WARN_ON(req == NULL); 1750e87506fSArnaldo Carvalho de Melo 1760e87506fSArnaldo Carvalho de Melo queue->rskq_accept_head = req->dl_next; 1770e87506fSArnaldo Carvalho de Melo if (queue->rskq_accept_head == NULL) 1780e87506fSArnaldo Carvalho de Melo queue->rskq_accept_tail = NULL; 1790e87506fSArnaldo Carvalho de Melo 1800e87506fSArnaldo Carvalho de Melo return req; 1810e87506fSArnaldo Carvalho de Melo } 1820e87506fSArnaldo Carvalho de Melo 1830e87506fSArnaldo Carvalho de Melo static inline struct sock *reqsk_queue_get_child(struct request_sock_queue *queue, 1840e87506fSArnaldo Carvalho de Melo struct sock *parent) 1850e87506fSArnaldo Carvalho de Melo { 1860e87506fSArnaldo Carvalho de Melo struct request_sock *req = reqsk_queue_remove(queue); 1870e87506fSArnaldo Carvalho de Melo struct sock *child = req->sk; 1880e87506fSArnaldo Carvalho de Melo 189547b792cSIlpo Järvinen WARN_ON(child == NULL); 1900e87506fSArnaldo Carvalho de Melo 1910e87506fSArnaldo Carvalho de Melo sk_acceptq_removed(parent); 1920e87506fSArnaldo Carvalho de Melo __reqsk_free(req); 1930e87506fSArnaldo Carvalho de Melo return child; 1940e87506fSArnaldo Carvalho de Melo } 1950e87506fSArnaldo Carvalho de Melo 1960e87506fSArnaldo Carvalho de Melo static inline int reqsk_queue_removed(struct request_sock_queue *queue, 1970e87506fSArnaldo Carvalho de Melo struct request_sock *req) 1980e87506fSArnaldo Carvalho de Melo { 1992ad69c55SArnaldo Carvalho de Melo struct listen_sock *lopt = queue->listen_opt; 2000e87506fSArnaldo Carvalho de Melo 2010e87506fSArnaldo Carvalho de Melo if (req->retrans == 0) 2020e87506fSArnaldo Carvalho de Melo --lopt->qlen_young; 2030e87506fSArnaldo Carvalho de Melo 2040e87506fSArnaldo Carvalho de Melo return --lopt->qlen; 2050e87506fSArnaldo Carvalho de Melo } 2060e87506fSArnaldo Carvalho de Melo 2070e87506fSArnaldo Carvalho de Melo static inline int reqsk_queue_added(struct request_sock_queue *queue) 2080e87506fSArnaldo Carvalho de Melo { 2092ad69c55SArnaldo Carvalho de Melo struct listen_sock *lopt = queue->listen_opt; 2100e87506fSArnaldo Carvalho de Melo const int prev_qlen = lopt->qlen; 2110e87506fSArnaldo Carvalho de Melo 2120e87506fSArnaldo Carvalho de Melo lopt->qlen_young++; 2130e87506fSArnaldo Carvalho de Melo lopt->qlen++; 2140e87506fSArnaldo Carvalho de Melo return prev_qlen; 2150e87506fSArnaldo Carvalho de Melo } 2160e87506fSArnaldo Carvalho de Melo 217463c84b9SArnaldo Carvalho de Melo static inline int reqsk_queue_len(const struct request_sock_queue *queue) 2180e87506fSArnaldo Carvalho de Melo { 2190e87506fSArnaldo Carvalho de Melo return queue->listen_opt != NULL ? queue->listen_opt->qlen : 0; 2200e87506fSArnaldo Carvalho de Melo } 2210e87506fSArnaldo Carvalho de Melo 222463c84b9SArnaldo Carvalho de Melo static inline int reqsk_queue_len_young(const struct request_sock_queue *queue) 2230e87506fSArnaldo Carvalho de Melo { 2240e87506fSArnaldo Carvalho de Melo return queue->listen_opt->qlen_young; 2250e87506fSArnaldo Carvalho de Melo } 2260e87506fSArnaldo Carvalho de Melo 227463c84b9SArnaldo Carvalho de Melo static inline int reqsk_queue_is_full(const struct request_sock_queue *queue) 2280e87506fSArnaldo Carvalho de Melo { 2290e87506fSArnaldo Carvalho de Melo return queue->listen_opt->qlen >> queue->listen_opt->max_qlen_log; 2300e87506fSArnaldo Carvalho de Melo } 2310e87506fSArnaldo Carvalho de Melo 2320e87506fSArnaldo Carvalho de Melo static inline void reqsk_queue_hash_req(struct request_sock_queue *queue, 2330e87506fSArnaldo Carvalho de Melo u32 hash, struct request_sock *req, 2348129765aSArnaldo Carvalho de Melo unsigned long timeout) 2350e87506fSArnaldo Carvalho de Melo { 2362ad69c55SArnaldo Carvalho de Melo struct listen_sock *lopt = queue->listen_opt; 2370e87506fSArnaldo Carvalho de Melo 2380e87506fSArnaldo Carvalho de Melo req->expires = jiffies + timeout; 2390e87506fSArnaldo Carvalho de Melo req->retrans = 0; 2400e87506fSArnaldo Carvalho de Melo req->sk = NULL; 2410e87506fSArnaldo Carvalho de Melo req->dl_next = lopt->syn_table[hash]; 2420e87506fSArnaldo Carvalho de Melo 2430e87506fSArnaldo Carvalho de Melo write_lock(&queue->syn_wait_lock); 2440e87506fSArnaldo Carvalho de Melo lopt->syn_table[hash] = req; 2450e87506fSArnaldo Carvalho de Melo write_unlock(&queue->syn_wait_lock); 2460e87506fSArnaldo Carvalho de Melo } 2470e87506fSArnaldo Carvalho de Melo 2482e6599cbSArnaldo Carvalho de Melo #endif /* _REQUEST_SOCK_H */ 249