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 30e6b4d113SWilliam Allen Simpson /* empty to "strongly type" an otherwise void parameter. 31e6b4d113SWilliam Allen Simpson */ 32e6b4d113SWilliam Allen Simpson struct request_values { 33e6b4d113SWilliam Allen Simpson }; 34e6b4d113SWilliam Allen Simpson 3560236fddSArnaldo Carvalho de Melo struct request_sock_ops { 362e6599cbSArnaldo Carvalho de Melo int family; 372e6599cbSArnaldo Carvalho de Melo int obj_size; 38e18b890bSChristoph Lameter struct kmem_cache *slab; 397e56b5d6SCatalin Marinas char *slab_name; 402e6599cbSArnaldo Carvalho de Melo int (*rtx_syn_ack)(struct sock *sk, 41e6b4d113SWilliam Allen Simpson struct request_sock *req, 42e6b4d113SWilliam Allen Simpson struct request_values *rvp); 436edafaafSGui Jianfeng void (*send_ack)(struct sock *sk, struct sk_buff *skb, 4460236fddSArnaldo Carvalho de Melo struct request_sock *req); 45cfb6eeb4SYOSHIFUJI Hideaki void (*send_reset)(struct sock *sk, 46cfb6eeb4SYOSHIFUJI Hideaki struct sk_buff *skb); 4760236fddSArnaldo Carvalho de Melo void (*destructor)(struct request_sock *req); 482e6599cbSArnaldo Carvalho de Melo }; 492e6599cbSArnaldo Carvalho de Melo 5060236fddSArnaldo Carvalho de Melo /* struct request_sock - mini sock to represent a connection request 512e6599cbSArnaldo Carvalho de Melo */ 5260236fddSArnaldo Carvalho de Melo struct request_sock { 5360236fddSArnaldo Carvalho de Melo struct request_sock *dl_next; /* Must be first member! */ 542e6599cbSArnaldo Carvalho de Melo u16 mss; 552e6599cbSArnaldo Carvalho de Melo u8 retrans; 564dfc2817SFlorian Westphal u8 cookie_ts; /* syncookie: encode tcpopts in timestamp */ 572e6599cbSArnaldo Carvalho de Melo /* The following two fields can be easily recomputed I think -AK */ 582e6599cbSArnaldo Carvalho de Melo u32 window_clamp; /* window clamp at creation time */ 592e6599cbSArnaldo Carvalho de Melo u32 rcv_wnd; /* rcv_wnd offered first time */ 602e6599cbSArnaldo Carvalho de Melo u32 ts_recent; 612e6599cbSArnaldo Carvalho de Melo unsigned long expires; 6272a3effaSEric Dumazet const struct request_sock_ops *rsk_ops; 632e6599cbSArnaldo Carvalho de Melo struct sock *sk; 644237c75cSVenkat Yekkirala u32 secid; 656b877699SVenkat Yekkirala u32 peer_secid; 662e6599cbSArnaldo Carvalho de Melo }; 672e6599cbSArnaldo Carvalho de Melo 6872a3effaSEric Dumazet static inline struct request_sock *reqsk_alloc(const struct request_sock_ops *ops) 692e6599cbSArnaldo Carvalho de Melo { 7054e6ecb2SChristoph Lameter struct request_sock *req = kmem_cache_alloc(ops->slab, GFP_ATOMIC); 712e6599cbSArnaldo Carvalho de Melo 722e6599cbSArnaldo Carvalho de Melo if (req != NULL) 7360236fddSArnaldo Carvalho de Melo req->rsk_ops = ops; 742e6599cbSArnaldo Carvalho de Melo 752e6599cbSArnaldo Carvalho de Melo return req; 762e6599cbSArnaldo Carvalho de Melo } 772e6599cbSArnaldo Carvalho de Melo 7860236fddSArnaldo Carvalho de Melo static inline void __reqsk_free(struct request_sock *req) 792e6599cbSArnaldo Carvalho de Melo { 8060236fddSArnaldo Carvalho de Melo kmem_cache_free(req->rsk_ops->slab, req); 812e6599cbSArnaldo Carvalho de Melo } 822e6599cbSArnaldo Carvalho de Melo 8360236fddSArnaldo Carvalho de Melo static inline void reqsk_free(struct request_sock *req) 842e6599cbSArnaldo Carvalho de Melo { 8560236fddSArnaldo Carvalho de Melo req->rsk_ops->destructor(req); 8660236fddSArnaldo Carvalho de Melo __reqsk_free(req); 872e6599cbSArnaldo Carvalho de Melo } 882e6599cbSArnaldo Carvalho de Melo 890e87506fSArnaldo Carvalho de Melo extern int sysctl_max_syn_backlog; 900e87506fSArnaldo Carvalho de Melo 912ad69c55SArnaldo Carvalho de Melo /** struct listen_sock - listen state 920e87506fSArnaldo Carvalho de Melo * 930e87506fSArnaldo Carvalho de Melo * @max_qlen_log - log_2 of maximal queued SYNs/REQUESTs 940e87506fSArnaldo Carvalho de Melo */ 952ad69c55SArnaldo Carvalho de Melo struct listen_sock { 960e87506fSArnaldo Carvalho de Melo u8 max_qlen_log; 970e87506fSArnaldo Carvalho de Melo /* 3 bytes hole, try to use */ 980e87506fSArnaldo Carvalho de Melo int qlen; 990e87506fSArnaldo Carvalho de Melo int qlen_young; 1000e87506fSArnaldo Carvalho de Melo int clock_hand; 1010e87506fSArnaldo Carvalho de Melo u32 hash_rnd; 10283e3609eSArnaldo Carvalho de Melo u32 nr_table_entries; 1030e87506fSArnaldo Carvalho de Melo struct request_sock *syn_table[0]; 1040e87506fSArnaldo Carvalho de Melo }; 1050e87506fSArnaldo Carvalho de Melo 1060e87506fSArnaldo Carvalho de Melo /** struct request_sock_queue - queue of request_socks 1070e87506fSArnaldo Carvalho de Melo * 1080e87506fSArnaldo Carvalho de Melo * @rskq_accept_head - FIFO head of established children 1090e87506fSArnaldo Carvalho de Melo * @rskq_accept_tail - FIFO tail of established children 110295f7324SArnaldo Carvalho de Melo * @rskq_defer_accept - User waits for some data after accept() 1110e87506fSArnaldo Carvalho de Melo * @syn_wait_lock - serializer 1120e87506fSArnaldo Carvalho de Melo * 1130e87506fSArnaldo Carvalho de Melo * %syn_wait_lock is necessary only to avoid proc interface having to grab the main 1140e87506fSArnaldo Carvalho de Melo * lock sock while browsing the listening hash (otherwise it's deadlock prone). 1150e87506fSArnaldo Carvalho de Melo * 1160e87506fSArnaldo Carvalho de Melo * This lock is acquired in read mode only from listening_get_next() seq_file 1170e87506fSArnaldo Carvalho de Melo * op and it's acquired in write mode _only_ from code that is actively 1180e87506fSArnaldo Carvalho de Melo * changing rskq_accept_head. All readers that are holding the master sock lock 1190e87506fSArnaldo Carvalho de Melo * don't need to grab this lock in read mode too as rskq_accept_head. writes 1200e87506fSArnaldo Carvalho de Melo * are always protected from the main sock lock. 1210e87506fSArnaldo Carvalho de Melo */ 1220e87506fSArnaldo Carvalho de Melo struct request_sock_queue { 1230e87506fSArnaldo Carvalho de Melo struct request_sock *rskq_accept_head; 1240e87506fSArnaldo Carvalho de Melo struct request_sock *rskq_accept_tail; 1250e87506fSArnaldo Carvalho de Melo rwlock_t syn_wait_lock; 126ec0a1966SDavid S. Miller u8 rskq_defer_accept; 127ec0a1966SDavid S. Miller /* 3 bytes hole, try to pack */ 1282ad69c55SArnaldo Carvalho de Melo struct listen_sock *listen_opt; 1290e87506fSArnaldo Carvalho de Melo }; 1300e87506fSArnaldo Carvalho de Melo 1310e87506fSArnaldo Carvalho de Melo extern int reqsk_queue_alloc(struct request_sock_queue *queue, 13272a3effaSEric Dumazet unsigned int nr_table_entries); 1330e87506fSArnaldo Carvalho de Melo 134dab6ba36SPavel Emelyanov extern void __reqsk_queue_destroy(struct request_sock_queue *queue); 13583e3609eSArnaldo Carvalho de Melo extern void reqsk_queue_destroy(struct request_sock_queue *queue); 13683e3609eSArnaldo Carvalho de Melo 1370e87506fSArnaldo Carvalho de Melo static inline struct request_sock * 1380e87506fSArnaldo Carvalho de Melo reqsk_queue_yank_acceptq(struct request_sock_queue *queue) 1390e87506fSArnaldo Carvalho de Melo { 1400e87506fSArnaldo Carvalho de Melo struct request_sock *req = queue->rskq_accept_head; 1410e87506fSArnaldo Carvalho de Melo 1423eb4801dSNorbert Kiesel queue->rskq_accept_head = NULL; 1430e87506fSArnaldo Carvalho de Melo return req; 1440e87506fSArnaldo Carvalho de Melo } 1450e87506fSArnaldo Carvalho de Melo 1460e87506fSArnaldo Carvalho de Melo static inline int reqsk_queue_empty(struct request_sock_queue *queue) 1470e87506fSArnaldo Carvalho de Melo { 1480e87506fSArnaldo Carvalho de Melo return queue->rskq_accept_head == NULL; 1490e87506fSArnaldo Carvalho de Melo } 1500e87506fSArnaldo Carvalho de Melo 1510e87506fSArnaldo Carvalho de Melo static inline void reqsk_queue_unlink(struct request_sock_queue *queue, 1520e87506fSArnaldo Carvalho de Melo struct request_sock *req, 1530e87506fSArnaldo Carvalho de Melo struct request_sock **prev_req) 1540e87506fSArnaldo Carvalho de Melo { 1550e87506fSArnaldo Carvalho de Melo write_lock(&queue->syn_wait_lock); 1560e87506fSArnaldo Carvalho de Melo *prev_req = req->dl_next; 1570e87506fSArnaldo Carvalho de Melo write_unlock(&queue->syn_wait_lock); 1580e87506fSArnaldo Carvalho de Melo } 1590e87506fSArnaldo Carvalho de Melo 1600e87506fSArnaldo Carvalho de Melo static inline void reqsk_queue_add(struct request_sock_queue *queue, 1610e87506fSArnaldo Carvalho de Melo struct request_sock *req, 1620e87506fSArnaldo Carvalho de Melo struct sock *parent, 1630e87506fSArnaldo Carvalho de Melo struct sock *child) 1640e87506fSArnaldo Carvalho de Melo { 1650e87506fSArnaldo Carvalho de Melo req->sk = child; 1660e87506fSArnaldo Carvalho de Melo sk_acceptq_added(parent); 1670e87506fSArnaldo Carvalho de Melo 1680e87506fSArnaldo Carvalho de Melo if (queue->rskq_accept_head == NULL) 1690e87506fSArnaldo Carvalho de Melo queue->rskq_accept_head = req; 1700e87506fSArnaldo Carvalho de Melo else 1710e87506fSArnaldo Carvalho de Melo queue->rskq_accept_tail->dl_next = req; 1720e87506fSArnaldo Carvalho de Melo 1730e87506fSArnaldo Carvalho de Melo queue->rskq_accept_tail = req; 1740e87506fSArnaldo Carvalho de Melo req->dl_next = NULL; 1750e87506fSArnaldo Carvalho de Melo } 1760e87506fSArnaldo Carvalho de Melo 1770e87506fSArnaldo Carvalho de Melo static inline struct request_sock *reqsk_queue_remove(struct request_sock_queue *queue) 1780e87506fSArnaldo Carvalho de Melo { 1790e87506fSArnaldo Carvalho de Melo struct request_sock *req = queue->rskq_accept_head; 1800e87506fSArnaldo Carvalho de Melo 181547b792cSIlpo Järvinen WARN_ON(req == NULL); 1820e87506fSArnaldo Carvalho de Melo 1830e87506fSArnaldo Carvalho de Melo queue->rskq_accept_head = req->dl_next; 1840e87506fSArnaldo Carvalho de Melo if (queue->rskq_accept_head == NULL) 1850e87506fSArnaldo Carvalho de Melo queue->rskq_accept_tail = NULL; 1860e87506fSArnaldo Carvalho de Melo 1870e87506fSArnaldo Carvalho de Melo return req; 1880e87506fSArnaldo Carvalho de Melo } 1890e87506fSArnaldo Carvalho de Melo 1900e87506fSArnaldo Carvalho de Melo static inline struct sock *reqsk_queue_get_child(struct request_sock_queue *queue, 1910e87506fSArnaldo Carvalho de Melo struct sock *parent) 1920e87506fSArnaldo Carvalho de Melo { 1930e87506fSArnaldo Carvalho de Melo struct request_sock *req = reqsk_queue_remove(queue); 1940e87506fSArnaldo Carvalho de Melo struct sock *child = req->sk; 1950e87506fSArnaldo Carvalho de Melo 196547b792cSIlpo Järvinen WARN_ON(child == NULL); 1970e87506fSArnaldo Carvalho de Melo 1980e87506fSArnaldo Carvalho de Melo sk_acceptq_removed(parent); 1990e87506fSArnaldo Carvalho de Melo __reqsk_free(req); 2000e87506fSArnaldo Carvalho de Melo return child; 2010e87506fSArnaldo Carvalho de Melo } 2020e87506fSArnaldo Carvalho de Melo 2030e87506fSArnaldo Carvalho de Melo static inline int reqsk_queue_removed(struct request_sock_queue *queue, 2040e87506fSArnaldo Carvalho de Melo struct request_sock *req) 2050e87506fSArnaldo Carvalho de Melo { 2062ad69c55SArnaldo Carvalho de Melo struct listen_sock *lopt = queue->listen_opt; 2070e87506fSArnaldo Carvalho de Melo 2080e87506fSArnaldo Carvalho de Melo if (req->retrans == 0) 2090e87506fSArnaldo Carvalho de Melo --lopt->qlen_young; 2100e87506fSArnaldo Carvalho de Melo 2110e87506fSArnaldo Carvalho de Melo return --lopt->qlen; 2120e87506fSArnaldo Carvalho de Melo } 2130e87506fSArnaldo Carvalho de Melo 2140e87506fSArnaldo Carvalho de Melo static inline int reqsk_queue_added(struct request_sock_queue *queue) 2150e87506fSArnaldo Carvalho de Melo { 2162ad69c55SArnaldo Carvalho de Melo struct listen_sock *lopt = queue->listen_opt; 2170e87506fSArnaldo Carvalho de Melo const int prev_qlen = lopt->qlen; 2180e87506fSArnaldo Carvalho de Melo 2190e87506fSArnaldo Carvalho de Melo lopt->qlen_young++; 2200e87506fSArnaldo Carvalho de Melo lopt->qlen++; 2210e87506fSArnaldo Carvalho de Melo return prev_qlen; 2220e87506fSArnaldo Carvalho de Melo } 2230e87506fSArnaldo Carvalho de Melo 224463c84b9SArnaldo Carvalho de Melo static inline int reqsk_queue_len(const struct request_sock_queue *queue) 2250e87506fSArnaldo Carvalho de Melo { 2260e87506fSArnaldo Carvalho de Melo return queue->listen_opt != NULL ? queue->listen_opt->qlen : 0; 2270e87506fSArnaldo Carvalho de Melo } 2280e87506fSArnaldo Carvalho de Melo 229463c84b9SArnaldo Carvalho de Melo static inline int reqsk_queue_len_young(const struct request_sock_queue *queue) 2300e87506fSArnaldo Carvalho de Melo { 2310e87506fSArnaldo Carvalho de Melo return queue->listen_opt->qlen_young; 2320e87506fSArnaldo Carvalho de Melo } 2330e87506fSArnaldo Carvalho de Melo 234463c84b9SArnaldo Carvalho de Melo static inline int reqsk_queue_is_full(const struct request_sock_queue *queue) 2350e87506fSArnaldo Carvalho de Melo { 2360e87506fSArnaldo Carvalho de Melo return queue->listen_opt->qlen >> queue->listen_opt->max_qlen_log; 2370e87506fSArnaldo Carvalho de Melo } 2380e87506fSArnaldo Carvalho de Melo 2390e87506fSArnaldo Carvalho de Melo static inline void reqsk_queue_hash_req(struct request_sock_queue *queue, 2400e87506fSArnaldo Carvalho de Melo u32 hash, struct request_sock *req, 2418129765aSArnaldo Carvalho de Melo unsigned long timeout) 2420e87506fSArnaldo Carvalho de Melo { 2432ad69c55SArnaldo Carvalho de Melo struct listen_sock *lopt = queue->listen_opt; 2440e87506fSArnaldo Carvalho de Melo 2450e87506fSArnaldo Carvalho de Melo req->expires = jiffies + timeout; 2460e87506fSArnaldo Carvalho de Melo req->retrans = 0; 2470e87506fSArnaldo Carvalho de Melo req->sk = NULL; 2480e87506fSArnaldo Carvalho de Melo req->dl_next = lopt->syn_table[hash]; 2490e87506fSArnaldo Carvalho de Melo 2500e87506fSArnaldo Carvalho de Melo write_lock(&queue->syn_wait_lock); 2510e87506fSArnaldo Carvalho de Melo lopt->syn_table[hash] = req; 2520e87506fSArnaldo Carvalho de Melo write_unlock(&queue->syn_wait_lock); 2530e87506fSArnaldo Carvalho de Melo } 2540e87506fSArnaldo Carvalho de Melo 2552e6599cbSArnaldo Carvalho de Melo #endif /* _REQUEST_SOCK_H */ 256