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> 210e87506fSArnaldo Carvalho de Melo 222e6599cbSArnaldo Carvalho de Melo #include <net/sock.h> 232e6599cbSArnaldo Carvalho de Melo 2460236fddSArnaldo Carvalho de Melo struct request_sock; 252e6599cbSArnaldo Carvalho de Melo struct sk_buff; 262e6599cbSArnaldo Carvalho de Melo struct dst_entry; 272e6599cbSArnaldo Carvalho de Melo struct proto; 282e6599cbSArnaldo Carvalho de Melo 2960236fddSArnaldo Carvalho de Melo struct request_sock_ops { 302e6599cbSArnaldo Carvalho de Melo int family; 312e6599cbSArnaldo Carvalho de Melo kmem_cache_t *slab; 322e6599cbSArnaldo Carvalho de Melo int obj_size; 332e6599cbSArnaldo Carvalho de Melo int (*rtx_syn_ack)(struct sock *sk, 3460236fddSArnaldo Carvalho de Melo struct request_sock *req, 352e6599cbSArnaldo Carvalho de Melo struct dst_entry *dst); 362e6599cbSArnaldo Carvalho de Melo void (*send_ack)(struct sk_buff *skb, 3760236fddSArnaldo Carvalho de Melo struct request_sock *req); 382e6599cbSArnaldo Carvalho de Melo void (*send_reset)(struct sk_buff *skb); 3960236fddSArnaldo Carvalho de Melo void (*destructor)(struct request_sock *req); 402e6599cbSArnaldo Carvalho de Melo }; 412e6599cbSArnaldo Carvalho de Melo 4260236fddSArnaldo Carvalho de Melo /* struct request_sock - mini sock to represent a connection request 432e6599cbSArnaldo Carvalho de Melo */ 4460236fddSArnaldo Carvalho de Melo struct request_sock { 4560236fddSArnaldo Carvalho de Melo struct request_sock *dl_next; /* Must be first member! */ 462e6599cbSArnaldo Carvalho de Melo u16 mss; 472e6599cbSArnaldo Carvalho de Melo u8 retrans; 482e6599cbSArnaldo Carvalho de Melo u8 __pad; 492e6599cbSArnaldo Carvalho de Melo /* The following two fields can be easily recomputed I think -AK */ 502e6599cbSArnaldo Carvalho de Melo u32 window_clamp; /* window clamp at creation time */ 512e6599cbSArnaldo Carvalho de Melo u32 rcv_wnd; /* rcv_wnd offered first time */ 522e6599cbSArnaldo Carvalho de Melo u32 ts_recent; 532e6599cbSArnaldo Carvalho de Melo unsigned long expires; 5460236fddSArnaldo Carvalho de Melo struct request_sock_ops *rsk_ops; 552e6599cbSArnaldo Carvalho de Melo struct sock *sk; 562e6599cbSArnaldo Carvalho de Melo }; 572e6599cbSArnaldo Carvalho de Melo 5860236fddSArnaldo Carvalho de Melo static inline struct request_sock *reqsk_alloc(struct request_sock_ops *ops) 592e6599cbSArnaldo Carvalho de Melo { 6060236fddSArnaldo Carvalho de Melo struct request_sock *req = kmem_cache_alloc(ops->slab, SLAB_ATOMIC); 612e6599cbSArnaldo Carvalho de Melo 622e6599cbSArnaldo Carvalho de Melo if (req != NULL) 6360236fddSArnaldo Carvalho de Melo req->rsk_ops = ops; 642e6599cbSArnaldo Carvalho de Melo 652e6599cbSArnaldo Carvalho de Melo return req; 662e6599cbSArnaldo Carvalho de Melo } 672e6599cbSArnaldo Carvalho de Melo 6860236fddSArnaldo Carvalho de Melo static inline void __reqsk_free(struct request_sock *req) 692e6599cbSArnaldo Carvalho de Melo { 7060236fddSArnaldo Carvalho de Melo kmem_cache_free(req->rsk_ops->slab, req); 712e6599cbSArnaldo Carvalho de Melo } 722e6599cbSArnaldo Carvalho de Melo 7360236fddSArnaldo Carvalho de Melo static inline void reqsk_free(struct request_sock *req) 742e6599cbSArnaldo Carvalho de Melo { 7560236fddSArnaldo Carvalho de Melo req->rsk_ops->destructor(req); 7660236fddSArnaldo Carvalho de Melo __reqsk_free(req); 772e6599cbSArnaldo Carvalho de Melo } 782e6599cbSArnaldo Carvalho de Melo 790e87506fSArnaldo Carvalho de Melo extern int sysctl_max_syn_backlog; 800e87506fSArnaldo Carvalho de Melo 812ad69c55SArnaldo Carvalho de Melo /** struct listen_sock - listen state 820e87506fSArnaldo Carvalho de Melo * 830e87506fSArnaldo Carvalho de Melo * @max_qlen_log - log_2 of maximal queued SYNs/REQUESTs 840e87506fSArnaldo Carvalho de Melo */ 852ad69c55SArnaldo Carvalho de Melo struct listen_sock { 860e87506fSArnaldo Carvalho de Melo u8 max_qlen_log; 870e87506fSArnaldo Carvalho de Melo /* 3 bytes hole, try to use */ 880e87506fSArnaldo Carvalho de Melo int qlen; 890e87506fSArnaldo Carvalho de Melo int qlen_young; 900e87506fSArnaldo Carvalho de Melo int clock_hand; 910e87506fSArnaldo Carvalho de Melo u32 hash_rnd; 920e87506fSArnaldo Carvalho de Melo struct request_sock *syn_table[0]; 930e87506fSArnaldo Carvalho de Melo }; 940e87506fSArnaldo Carvalho de Melo 950e87506fSArnaldo Carvalho de Melo /** struct request_sock_queue - queue of request_socks 960e87506fSArnaldo Carvalho de Melo * 970e87506fSArnaldo Carvalho de Melo * @rskq_accept_head - FIFO head of established children 980e87506fSArnaldo Carvalho de Melo * @rskq_accept_tail - FIFO tail of established children 990e87506fSArnaldo Carvalho de Melo * @syn_wait_lock - serializer 1000e87506fSArnaldo Carvalho de Melo * 1010e87506fSArnaldo Carvalho de Melo * %syn_wait_lock is necessary only to avoid proc interface having to grab the main 1020e87506fSArnaldo Carvalho de Melo * lock sock while browsing the listening hash (otherwise it's deadlock prone). 1030e87506fSArnaldo Carvalho de Melo * 1040e87506fSArnaldo Carvalho de Melo * This lock is acquired in read mode only from listening_get_next() seq_file 1050e87506fSArnaldo Carvalho de Melo * op and it's acquired in write mode _only_ from code that is actively 1060e87506fSArnaldo Carvalho de Melo * changing rskq_accept_head. All readers that are holding the master sock lock 1070e87506fSArnaldo Carvalho de Melo * don't need to grab this lock in read mode too as rskq_accept_head. writes 1080e87506fSArnaldo Carvalho de Melo * are always protected from the main sock lock. 1090e87506fSArnaldo Carvalho de Melo */ 1100e87506fSArnaldo Carvalho de Melo struct request_sock_queue { 1110e87506fSArnaldo Carvalho de Melo struct request_sock *rskq_accept_head; 1120e87506fSArnaldo Carvalho de Melo struct request_sock *rskq_accept_tail; 1130e87506fSArnaldo Carvalho de Melo rwlock_t syn_wait_lock; 1142ad69c55SArnaldo Carvalho de Melo struct listen_sock *listen_opt; 1150e87506fSArnaldo Carvalho de Melo }; 1160e87506fSArnaldo Carvalho de Melo 1170e87506fSArnaldo Carvalho de Melo extern int reqsk_queue_alloc(struct request_sock_queue *queue, 1180e87506fSArnaldo Carvalho de Melo const int nr_table_entries); 1190e87506fSArnaldo Carvalho de Melo 1202ad69c55SArnaldo Carvalho de Melo static inline struct listen_sock *reqsk_queue_yank_listen_sk(struct request_sock_queue *queue) 1210e87506fSArnaldo Carvalho de Melo { 1222ad69c55SArnaldo Carvalho de Melo struct listen_sock *lopt; 1230e87506fSArnaldo Carvalho de Melo 1240e87506fSArnaldo Carvalho de Melo write_lock_bh(&queue->syn_wait_lock); 1250e87506fSArnaldo Carvalho de Melo lopt = queue->listen_opt; 1260e87506fSArnaldo Carvalho de Melo queue->listen_opt = NULL; 1270e87506fSArnaldo Carvalho de Melo write_unlock_bh(&queue->syn_wait_lock); 1280e87506fSArnaldo Carvalho de Melo 1290e87506fSArnaldo Carvalho de Melo return lopt; 1300e87506fSArnaldo Carvalho de Melo } 1310e87506fSArnaldo Carvalho de Melo 1320e87506fSArnaldo Carvalho de Melo static inline void reqsk_queue_destroy(struct request_sock_queue *queue) 1330e87506fSArnaldo Carvalho de Melo { 1340e87506fSArnaldo Carvalho de Melo kfree(reqsk_queue_yank_listen_sk(queue)); 1350e87506fSArnaldo Carvalho de Melo } 1360e87506fSArnaldo 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 1420e87506fSArnaldo Carvalho de Melo queue->rskq_accept_head = 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 1810e87506fSArnaldo Carvalho de Melo BUG_TRAP(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 1960e87506fSArnaldo Carvalho de Melo BUG_TRAP(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 2240e87506fSArnaldo Carvalho de Melo static inline int reqsk_queue_len(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 2290e87506fSArnaldo Carvalho de Melo static inline int reqsk_queue_len_young(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 2340e87506fSArnaldo Carvalho de Melo static inline int reqsk_queue_is_full(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, 2410e87506fSArnaldo Carvalho de Melo unsigned 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