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); 4872659eccSOctavian Purdila void (*syn_ack_timeout)(struct sock *sk, 4972659eccSOctavian Purdila struct request_sock *req); 502e6599cbSArnaldo Carvalho de Melo }; 512e6599cbSArnaldo Carvalho de Melo 5260236fddSArnaldo Carvalho de Melo /* struct request_sock - mini sock to represent a connection request 532e6599cbSArnaldo Carvalho de Melo */ 5460236fddSArnaldo Carvalho de Melo struct request_sock { 5560236fddSArnaldo Carvalho de Melo struct request_sock *dl_next; /* Must be first member! */ 562e6599cbSArnaldo Carvalho de Melo u16 mss; 572e6599cbSArnaldo Carvalho de Melo u8 retrans; 584dfc2817SFlorian Westphal u8 cookie_ts; /* syncookie: encode tcpopts in timestamp */ 592e6599cbSArnaldo Carvalho de Melo /* The following two fields can be easily recomputed I think -AK */ 602e6599cbSArnaldo Carvalho de Melo u32 window_clamp; /* window clamp at creation time */ 612e6599cbSArnaldo Carvalho de Melo u32 rcv_wnd; /* rcv_wnd offered first time */ 622e6599cbSArnaldo Carvalho de Melo u32 ts_recent; 632e6599cbSArnaldo Carvalho de Melo unsigned long expires; 6472a3effaSEric Dumazet const struct request_sock_ops *rsk_ops; 652e6599cbSArnaldo Carvalho de Melo struct sock *sk; 664237c75cSVenkat Yekkirala u32 secid; 676b877699SVenkat Yekkirala u32 peer_secid; 682e6599cbSArnaldo Carvalho de Melo }; 692e6599cbSArnaldo Carvalho de Melo 7072a3effaSEric Dumazet static inline struct request_sock *reqsk_alloc(const struct request_sock_ops *ops) 712e6599cbSArnaldo Carvalho de Melo { 7254e6ecb2SChristoph Lameter struct request_sock *req = kmem_cache_alloc(ops->slab, GFP_ATOMIC); 732e6599cbSArnaldo Carvalho de Melo 742e6599cbSArnaldo Carvalho de Melo if (req != NULL) 7560236fddSArnaldo Carvalho de Melo req->rsk_ops = ops; 762e6599cbSArnaldo Carvalho de Melo 772e6599cbSArnaldo Carvalho de Melo return req; 782e6599cbSArnaldo Carvalho de Melo } 792e6599cbSArnaldo Carvalho de Melo 8060236fddSArnaldo Carvalho de Melo static inline void __reqsk_free(struct request_sock *req) 812e6599cbSArnaldo Carvalho de Melo { 8260236fddSArnaldo Carvalho de Melo kmem_cache_free(req->rsk_ops->slab, req); 832e6599cbSArnaldo Carvalho de Melo } 842e6599cbSArnaldo Carvalho de Melo 8560236fddSArnaldo Carvalho de Melo static inline void reqsk_free(struct request_sock *req) 862e6599cbSArnaldo Carvalho de Melo { 8760236fddSArnaldo Carvalho de Melo req->rsk_ops->destructor(req); 8860236fddSArnaldo Carvalho de Melo __reqsk_free(req); 892e6599cbSArnaldo Carvalho de Melo } 902e6599cbSArnaldo Carvalho de Melo 910e87506fSArnaldo Carvalho de Melo extern int sysctl_max_syn_backlog; 920e87506fSArnaldo Carvalho de Melo 932ad69c55SArnaldo Carvalho de Melo /** struct listen_sock - listen state 940e87506fSArnaldo Carvalho de Melo * 950e87506fSArnaldo Carvalho de Melo * @max_qlen_log - log_2 of maximal queued SYNs/REQUESTs 960e87506fSArnaldo Carvalho de Melo */ 972ad69c55SArnaldo Carvalho de Melo struct listen_sock { 980e87506fSArnaldo Carvalho de Melo u8 max_qlen_log; 99946cedccSEric Dumazet u8 synflood_warned; 100946cedccSEric Dumazet /* 2 bytes hole, try to use */ 1010e87506fSArnaldo Carvalho de Melo int qlen; 1020e87506fSArnaldo Carvalho de Melo int qlen_young; 1030e87506fSArnaldo Carvalho de Melo int clock_hand; 1040e87506fSArnaldo Carvalho de Melo u32 hash_rnd; 10583e3609eSArnaldo Carvalho de Melo u32 nr_table_entries; 1060e87506fSArnaldo Carvalho de Melo struct request_sock *syn_table[0]; 1070e87506fSArnaldo Carvalho de Melo }; 1080e87506fSArnaldo Carvalho de Melo 1090e87506fSArnaldo Carvalho de Melo /** struct request_sock_queue - queue of request_socks 1100e87506fSArnaldo Carvalho de Melo * 1110e87506fSArnaldo Carvalho de Melo * @rskq_accept_head - FIFO head of established children 1120e87506fSArnaldo Carvalho de Melo * @rskq_accept_tail - FIFO tail of established children 113295f7324SArnaldo Carvalho de Melo * @rskq_defer_accept - User waits for some data after accept() 1140e87506fSArnaldo Carvalho de Melo * @syn_wait_lock - serializer 1150e87506fSArnaldo Carvalho de Melo * 1160e87506fSArnaldo Carvalho de Melo * %syn_wait_lock is necessary only to avoid proc interface having to grab the main 1170e87506fSArnaldo Carvalho de Melo * lock sock while browsing the listening hash (otherwise it's deadlock prone). 1180e87506fSArnaldo Carvalho de Melo * 1190e87506fSArnaldo Carvalho de Melo * This lock is acquired in read mode only from listening_get_next() seq_file 1200e87506fSArnaldo Carvalho de Melo * op and it's acquired in write mode _only_ from code that is actively 1210e87506fSArnaldo Carvalho de Melo * changing rskq_accept_head. All readers that are holding the master sock lock 1220e87506fSArnaldo Carvalho de Melo * don't need to grab this lock in read mode too as rskq_accept_head. writes 1230e87506fSArnaldo Carvalho de Melo * are always protected from the main sock lock. 1240e87506fSArnaldo Carvalho de Melo */ 1250e87506fSArnaldo Carvalho de Melo struct request_sock_queue { 1260e87506fSArnaldo Carvalho de Melo struct request_sock *rskq_accept_head; 1270e87506fSArnaldo Carvalho de Melo struct request_sock *rskq_accept_tail; 1280e87506fSArnaldo Carvalho de Melo rwlock_t syn_wait_lock; 129ec0a1966SDavid S. Miller u8 rskq_defer_accept; 130ec0a1966SDavid S. Miller /* 3 bytes hole, try to pack */ 1312ad69c55SArnaldo Carvalho de Melo struct listen_sock *listen_opt; 1320e87506fSArnaldo Carvalho de Melo }; 1330e87506fSArnaldo Carvalho de Melo 1340e87506fSArnaldo Carvalho de Melo extern int reqsk_queue_alloc(struct request_sock_queue *queue, 13572a3effaSEric Dumazet unsigned int nr_table_entries); 1360e87506fSArnaldo Carvalho de Melo 137dab6ba36SPavel Emelyanov extern void __reqsk_queue_destroy(struct request_sock_queue *queue); 13883e3609eSArnaldo Carvalho de Melo extern void reqsk_queue_destroy(struct request_sock_queue *queue); 13983e3609eSArnaldo Carvalho de Melo 1400e87506fSArnaldo Carvalho de Melo static inline struct request_sock * 1410e87506fSArnaldo Carvalho de Melo reqsk_queue_yank_acceptq(struct request_sock_queue *queue) 1420e87506fSArnaldo Carvalho de Melo { 1430e87506fSArnaldo Carvalho de Melo struct request_sock *req = queue->rskq_accept_head; 1440e87506fSArnaldo Carvalho de Melo 1453eb4801dSNorbert Kiesel queue->rskq_accept_head = NULL; 1460e87506fSArnaldo Carvalho de Melo return req; 1470e87506fSArnaldo Carvalho de Melo } 1480e87506fSArnaldo Carvalho de Melo 1490e87506fSArnaldo Carvalho de Melo static inline int reqsk_queue_empty(struct request_sock_queue *queue) 1500e87506fSArnaldo Carvalho de Melo { 1510e87506fSArnaldo Carvalho de Melo return queue->rskq_accept_head == NULL; 1520e87506fSArnaldo Carvalho de Melo } 1530e87506fSArnaldo Carvalho de Melo 1540e87506fSArnaldo Carvalho de Melo static inline void reqsk_queue_unlink(struct request_sock_queue *queue, 1550e87506fSArnaldo Carvalho de Melo struct request_sock *req, 1560e87506fSArnaldo Carvalho de Melo struct request_sock **prev_req) 1570e87506fSArnaldo Carvalho de Melo { 1580e87506fSArnaldo Carvalho de Melo write_lock(&queue->syn_wait_lock); 1590e87506fSArnaldo Carvalho de Melo *prev_req = req->dl_next; 1600e87506fSArnaldo Carvalho de Melo write_unlock(&queue->syn_wait_lock); 1610e87506fSArnaldo Carvalho de Melo } 1620e87506fSArnaldo Carvalho de Melo 1630e87506fSArnaldo Carvalho de Melo static inline void reqsk_queue_add(struct request_sock_queue *queue, 1640e87506fSArnaldo Carvalho de Melo struct request_sock *req, 1650e87506fSArnaldo Carvalho de Melo struct sock *parent, 1660e87506fSArnaldo Carvalho de Melo struct sock *child) 1670e87506fSArnaldo Carvalho de Melo { 1680e87506fSArnaldo Carvalho de Melo req->sk = child; 1690e87506fSArnaldo Carvalho de Melo sk_acceptq_added(parent); 1700e87506fSArnaldo Carvalho de Melo 1710e87506fSArnaldo Carvalho de Melo if (queue->rskq_accept_head == NULL) 1720e87506fSArnaldo Carvalho de Melo queue->rskq_accept_head = req; 1730e87506fSArnaldo Carvalho de Melo else 1740e87506fSArnaldo Carvalho de Melo queue->rskq_accept_tail->dl_next = req; 1750e87506fSArnaldo Carvalho de Melo 1760e87506fSArnaldo Carvalho de Melo queue->rskq_accept_tail = req; 1770e87506fSArnaldo Carvalho de Melo req->dl_next = NULL; 1780e87506fSArnaldo Carvalho de Melo } 1790e87506fSArnaldo Carvalho de Melo 1800e87506fSArnaldo Carvalho de Melo static inline struct request_sock *reqsk_queue_remove(struct request_sock_queue *queue) 1810e87506fSArnaldo Carvalho de Melo { 1820e87506fSArnaldo Carvalho de Melo struct request_sock *req = queue->rskq_accept_head; 1830e87506fSArnaldo Carvalho de Melo 184547b792cSIlpo Järvinen WARN_ON(req == NULL); 1850e87506fSArnaldo Carvalho de Melo 1860e87506fSArnaldo Carvalho de Melo queue->rskq_accept_head = req->dl_next; 1870e87506fSArnaldo Carvalho de Melo if (queue->rskq_accept_head == NULL) 1880e87506fSArnaldo Carvalho de Melo queue->rskq_accept_tail = NULL; 1890e87506fSArnaldo Carvalho de Melo 1900e87506fSArnaldo Carvalho de Melo return req; 1910e87506fSArnaldo Carvalho de Melo } 1920e87506fSArnaldo Carvalho de Melo 1930e87506fSArnaldo Carvalho de Melo static inline struct sock *reqsk_queue_get_child(struct request_sock_queue *queue, 1940e87506fSArnaldo Carvalho de Melo struct sock *parent) 1950e87506fSArnaldo Carvalho de Melo { 1960e87506fSArnaldo Carvalho de Melo struct request_sock *req = reqsk_queue_remove(queue); 1970e87506fSArnaldo Carvalho de Melo struct sock *child = req->sk; 1980e87506fSArnaldo Carvalho de Melo 199547b792cSIlpo Järvinen WARN_ON(child == NULL); 2000e87506fSArnaldo Carvalho de Melo 2010e87506fSArnaldo Carvalho de Melo sk_acceptq_removed(parent); 2020e87506fSArnaldo Carvalho de Melo __reqsk_free(req); 2030e87506fSArnaldo Carvalho de Melo return child; 2040e87506fSArnaldo Carvalho de Melo } 2050e87506fSArnaldo Carvalho de Melo 2060e87506fSArnaldo Carvalho de Melo static inline int reqsk_queue_removed(struct request_sock_queue *queue, 2070e87506fSArnaldo Carvalho de Melo struct request_sock *req) 2080e87506fSArnaldo Carvalho de Melo { 2092ad69c55SArnaldo Carvalho de Melo struct listen_sock *lopt = queue->listen_opt; 2100e87506fSArnaldo Carvalho de Melo 2110e87506fSArnaldo Carvalho de Melo if (req->retrans == 0) 2120e87506fSArnaldo Carvalho de Melo --lopt->qlen_young; 2130e87506fSArnaldo Carvalho de Melo 2140e87506fSArnaldo Carvalho de Melo return --lopt->qlen; 2150e87506fSArnaldo Carvalho de Melo } 2160e87506fSArnaldo Carvalho de Melo 2170e87506fSArnaldo Carvalho de Melo static inline int reqsk_queue_added(struct request_sock_queue *queue) 2180e87506fSArnaldo Carvalho de Melo { 2192ad69c55SArnaldo Carvalho de Melo struct listen_sock *lopt = queue->listen_opt; 2200e87506fSArnaldo Carvalho de Melo const int prev_qlen = lopt->qlen; 2210e87506fSArnaldo Carvalho de Melo 2220e87506fSArnaldo Carvalho de Melo lopt->qlen_young++; 2230e87506fSArnaldo Carvalho de Melo lopt->qlen++; 2240e87506fSArnaldo Carvalho de Melo return prev_qlen; 2250e87506fSArnaldo Carvalho de Melo } 2260e87506fSArnaldo Carvalho de Melo 227463c84b9SArnaldo Carvalho de Melo static inline int reqsk_queue_len(const struct request_sock_queue *queue) 2280e87506fSArnaldo Carvalho de Melo { 2290e87506fSArnaldo Carvalho de Melo return queue->listen_opt != NULL ? queue->listen_opt->qlen : 0; 2300e87506fSArnaldo Carvalho de Melo } 2310e87506fSArnaldo Carvalho de Melo 232463c84b9SArnaldo Carvalho de Melo static inline int reqsk_queue_len_young(const struct request_sock_queue *queue) 2330e87506fSArnaldo Carvalho de Melo { 2340e87506fSArnaldo Carvalho de Melo return queue->listen_opt->qlen_young; 2350e87506fSArnaldo Carvalho de Melo } 2360e87506fSArnaldo Carvalho de Melo 237463c84b9SArnaldo Carvalho de Melo static inline int reqsk_queue_is_full(const struct request_sock_queue *queue) 2380e87506fSArnaldo Carvalho de Melo { 2390e87506fSArnaldo Carvalho de Melo return queue->listen_opt->qlen >> queue->listen_opt->max_qlen_log; 2400e87506fSArnaldo Carvalho de Melo } 2410e87506fSArnaldo Carvalho de Melo 2420e87506fSArnaldo Carvalho de Melo static inline void reqsk_queue_hash_req(struct request_sock_queue *queue, 2430e87506fSArnaldo Carvalho de Melo u32 hash, struct request_sock *req, 2448129765aSArnaldo Carvalho de Melo unsigned long timeout) 2450e87506fSArnaldo Carvalho de Melo { 2462ad69c55SArnaldo Carvalho de Melo struct listen_sock *lopt = queue->listen_opt; 2470e87506fSArnaldo Carvalho de Melo 2480e87506fSArnaldo Carvalho de Melo req->expires = jiffies + timeout; 2490e87506fSArnaldo Carvalho de Melo req->retrans = 0; 2500e87506fSArnaldo Carvalho de Melo req->sk = NULL; 2510e87506fSArnaldo Carvalho de Melo req->dl_next = lopt->syn_table[hash]; 2520e87506fSArnaldo Carvalho de Melo 2530e87506fSArnaldo Carvalho de Melo write_lock(&queue->syn_wait_lock); 2540e87506fSArnaldo Carvalho de Melo lopt->syn_table[hash] = req; 2550e87506fSArnaldo Carvalho de Melo write_unlock(&queue->syn_wait_lock); 2560e87506fSArnaldo Carvalho de Melo } 2570e87506fSArnaldo Carvalho de Melo 2582e6599cbSArnaldo Carvalho de Melo #endif /* _REQUEST_SOCK_H */ 259