Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 1 | /* |
| 2 | * NET Generic infrastructure for Network protocols. |
| 3 | * |
| 4 | * Definitions for request_sock |
| 5 | * |
| 6 | * Authors: Arnaldo Carvalho de Melo <acme@conectiva.com.br> |
| 7 | * |
| 8 | * From code originally in include/net/tcp.h |
| 9 | * |
| 10 | * This program is free software; you can redistribute it and/or |
| 11 | * modify it under the terms of the GNU General Public License |
| 12 | * as published by the Free Software Foundation; either version |
| 13 | * 2 of the License, or (at your option) any later version. |
| 14 | */ |
| 15 | #ifndef _REQUEST_SOCK_H |
| 16 | #define _REQUEST_SOCK_H |
| 17 | |
| 18 | #include <linux/slab.h> |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 19 | #include <linux/spinlock.h> |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 20 | #include <linux/types.h> |
Ilpo Järvinen | 547b792 | 2008-07-25 21:43:18 -0700 | [diff] [blame] | 21 | #include <linux/bug.h> |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 22 | |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 23 | #include <net/sock.h> |
| 24 | |
Arnaldo Carvalho de Melo | 60236fd | 2005-06-18 22:47:21 -0700 | [diff] [blame] | 25 | struct request_sock; |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 26 | struct sk_buff; |
| 27 | struct dst_entry; |
| 28 | struct proto; |
| 29 | |
Arnaldo Carvalho de Melo | 60236fd | 2005-06-18 22:47:21 -0700 | [diff] [blame] | 30 | struct request_sock_ops { |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 31 | int family; |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 32 | int obj_size; |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 33 | struct kmem_cache *slab; |
Catalin Marinas | 7e56b5d | 2008-11-21 16:45:22 -0800 | [diff] [blame] | 34 | char *slab_name; |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 35 | int (*rtx_syn_ack)(struct sock *sk, |
Christoph Paasch | 1a2c618 | 2013-03-17 08:23:34 +0000 | [diff] [blame] | 36 | struct request_sock *req); |
Gui Jianfeng | 6edafaa | 2008-08-06 23:50:04 -0700 | [diff] [blame] | 37 | void (*send_ack)(struct sock *sk, struct sk_buff *skb, |
Arnaldo Carvalho de Melo | 60236fd | 2005-06-18 22:47:21 -0700 | [diff] [blame] | 38 | struct request_sock *req); |
YOSHIFUJI Hideaki | cfb6eeb | 2006-11-14 19:07:45 -0800 | [diff] [blame] | 39 | void (*send_reset)(struct sock *sk, |
| 40 | struct sk_buff *skb); |
Arnaldo Carvalho de Melo | 60236fd | 2005-06-18 22:47:21 -0700 | [diff] [blame] | 41 | void (*destructor)(struct request_sock *req); |
Octavian Purdila | 72659ec | 2010-01-17 19:09:39 -0800 | [diff] [blame] | 42 | void (*syn_ack_timeout)(struct sock *sk, |
| 43 | struct request_sock *req); |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 44 | }; |
| 45 | |
Eric Dumazet | e6c022a | 2012-10-27 23:16:46 +0000 | [diff] [blame] | 46 | extern int inet_rtx_syn_ack(struct sock *parent, struct request_sock *req); |
| 47 | |
Arnaldo Carvalho de Melo | 60236fd | 2005-06-18 22:47:21 -0700 | [diff] [blame] | 48 | /* struct request_sock - mini sock to represent a connection request |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 49 | */ |
Arnaldo Carvalho de Melo | 60236fd | 2005-06-18 22:47:21 -0700 | [diff] [blame] | 50 | struct request_sock { |
Eric Dumazet | 3fb62c5 | 2013-04-19 14:29:25 -0700 | [diff] [blame] | 51 | struct request_sock *dl_next; |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 52 | u16 mss; |
Eric Dumazet | e6c022a | 2012-10-27 23:16:46 +0000 | [diff] [blame] | 53 | u8 num_retrans; /* number of retransmits */ |
| 54 | u8 cookie_ts:1; /* syncookie: encode tcpopts in timestamp */ |
| 55 | u8 num_timeout:7; /* number of timeouts */ |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 56 | /* The following two fields can be easily recomputed I think -AK */ |
| 57 | u32 window_clamp; /* window clamp at creation time */ |
| 58 | u32 rcv_wnd; /* rcv_wnd offered first time */ |
| 59 | u32 ts_recent; |
| 60 | unsigned long expires; |
Eric Dumazet | 72a3eff | 2006-11-16 02:30:37 -0800 | [diff] [blame] | 61 | const struct request_sock_ops *rsk_ops; |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 62 | struct sock *sk; |
Venkat Yekkirala | 4237c75 | 2006-07-24 23:32:50 -0700 | [diff] [blame] | 63 | u32 secid; |
Venkat Yekkirala | 6b87769 | 2006-11-08 17:04:09 -0600 | [diff] [blame] | 64 | u32 peer_secid; |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 65 | }; |
| 66 | |
Eric Dumazet | 72a3eff | 2006-11-16 02:30:37 -0800 | [diff] [blame] | 67 | static inline struct request_sock *reqsk_alloc(const struct request_sock_ops *ops) |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 68 | { |
Christoph Lameter | 54e6ecb | 2006-12-06 20:33:16 -0800 | [diff] [blame] | 69 | struct request_sock *req = kmem_cache_alloc(ops->slab, GFP_ATOMIC); |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 70 | |
| 71 | if (req != NULL) |
Arnaldo Carvalho de Melo | 60236fd | 2005-06-18 22:47:21 -0700 | [diff] [blame] | 72 | req->rsk_ops = ops; |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 73 | |
| 74 | return req; |
| 75 | } |
| 76 | |
Arnaldo Carvalho de Melo | 60236fd | 2005-06-18 22:47:21 -0700 | [diff] [blame] | 77 | static inline void __reqsk_free(struct request_sock *req) |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 78 | { |
Arnaldo Carvalho de Melo | 60236fd | 2005-06-18 22:47:21 -0700 | [diff] [blame] | 79 | kmem_cache_free(req->rsk_ops->slab, req); |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 80 | } |
| 81 | |
Arnaldo Carvalho de Melo | 60236fd | 2005-06-18 22:47:21 -0700 | [diff] [blame] | 82 | static inline void reqsk_free(struct request_sock *req) |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 83 | { |
Arnaldo Carvalho de Melo | 60236fd | 2005-06-18 22:47:21 -0700 | [diff] [blame] | 84 | req->rsk_ops->destructor(req); |
| 85 | __reqsk_free(req); |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 86 | } |
| 87 | |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 88 | extern int sysctl_max_syn_backlog; |
| 89 | |
Arnaldo Carvalho de Melo | 2ad69c5 | 2005-06-18 22:48:55 -0700 | [diff] [blame] | 90 | /** struct listen_sock - listen state |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 91 | * |
| 92 | * @max_qlen_log - log_2 of maximal queued SYNs/REQUESTs |
| 93 | */ |
Arnaldo Carvalho de Melo | 2ad69c5 | 2005-06-18 22:48:55 -0700 | [diff] [blame] | 94 | struct listen_sock { |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 95 | u8 max_qlen_log; |
Eric Dumazet | 946cedc | 2011-08-30 03:21:44 +0000 | [diff] [blame] | 96 | u8 synflood_warned; |
| 97 | /* 2 bytes hole, try to use */ |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 98 | int qlen; |
| 99 | int qlen_young; |
| 100 | int clock_hand; |
| 101 | u32 hash_rnd; |
Arnaldo Carvalho de Melo | 83e3609 | 2005-08-09 19:33:31 -0700 | [diff] [blame] | 102 | u32 nr_table_entries; |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 103 | struct request_sock *syn_table[0]; |
| 104 | }; |
| 105 | |
Jerry Chu | 1046716 | 2012-08-31 12:29:11 +0000 | [diff] [blame] | 106 | /* |
| 107 | * For a TCP Fast Open listener - |
| 108 | * lock - protects the access to all the reqsk, which is co-owned by |
| 109 | * the listener and the child socket. |
| 110 | * qlen - pending TFO requests (still in TCP_SYN_RECV). |
| 111 | * max_qlen - max TFO reqs allowed before TFO is disabled. |
| 112 | * |
| 113 | * XXX (TFO) - ideally these fields can be made as part of "listen_sock" |
| 114 | * structure above. But there is some implementation difficulty due to |
| 115 | * listen_sock being part of request_sock_queue hence will be freed when |
| 116 | * a listener is stopped. But TFO related fields may continue to be |
| 117 | * accessed even after a listener is closed, until its sk_refcnt drops |
| 118 | * to 0 implying no more outstanding TFO reqs. One solution is to keep |
| 119 | * listen_opt around until sk_refcnt drops to 0. But there is some other |
| 120 | * complexity that needs to be resolved. E.g., a listener can be disabled |
| 121 | * temporarily through shutdown()->tcp_disconnect(), and re-enabled later. |
| 122 | */ |
| 123 | struct fastopen_queue { |
| 124 | struct request_sock *rskq_rst_head; /* Keep track of past TFO */ |
| 125 | struct request_sock *rskq_rst_tail; /* requests that caused RST. |
| 126 | * This is part of the defense |
| 127 | * against spoofing attack. |
| 128 | */ |
| 129 | spinlock_t lock; |
| 130 | int qlen; /* # of pending (TCP_SYN_RECV) reqs */ |
| 131 | int max_qlen; /* != 0 iff TFO is currently enabled */ |
| 132 | }; |
| 133 | |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 134 | /** struct request_sock_queue - queue of request_socks |
| 135 | * |
| 136 | * @rskq_accept_head - FIFO head of established children |
| 137 | * @rskq_accept_tail - FIFO tail of established children |
Arnaldo Carvalho de Melo | 295f732 | 2005-08-09 20:11:56 -0700 | [diff] [blame] | 138 | * @rskq_defer_accept - User waits for some data after accept() |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 139 | * @syn_wait_lock - serializer |
| 140 | * |
| 141 | * %syn_wait_lock is necessary only to avoid proc interface having to grab the main |
| 142 | * lock sock while browsing the listening hash (otherwise it's deadlock prone). |
| 143 | * |
| 144 | * This lock is acquired in read mode only from listening_get_next() seq_file |
| 145 | * op and it's acquired in write mode _only_ from code that is actively |
| 146 | * changing rskq_accept_head. All readers that are holding the master sock lock |
| 147 | * don't need to grab this lock in read mode too as rskq_accept_head. writes |
| 148 | * are always protected from the main sock lock. |
| 149 | */ |
| 150 | struct request_sock_queue { |
| 151 | struct request_sock *rskq_accept_head; |
| 152 | struct request_sock *rskq_accept_tail; |
| 153 | rwlock_t syn_wait_lock; |
David S. Miller | ec0a196 | 2008-06-12 16:31:35 -0700 | [diff] [blame] | 154 | u8 rskq_defer_accept; |
| 155 | /* 3 bytes hole, try to pack */ |
Arnaldo Carvalho de Melo | 2ad69c5 | 2005-06-18 22:48:55 -0700 | [diff] [blame] | 156 | struct listen_sock *listen_opt; |
Jerry Chu | 1046716 | 2012-08-31 12:29:11 +0000 | [diff] [blame] | 157 | struct fastopen_queue *fastopenq; /* This is non-NULL iff TFO has been |
| 158 | * enabled on this listener. Check |
| 159 | * max_qlen != 0 in fastopen_queue |
| 160 | * to determine if TFO is enabled |
| 161 | * right at this moment. |
| 162 | */ |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 163 | }; |
| 164 | |
| 165 | extern int reqsk_queue_alloc(struct request_sock_queue *queue, |
Eric Dumazet | 72a3eff | 2006-11-16 02:30:37 -0800 | [diff] [blame] | 166 | unsigned int nr_table_entries); |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 167 | |
Pavel Emelyanov | dab6ba3 | 2007-11-15 02:57:06 -0800 | [diff] [blame] | 168 | extern void __reqsk_queue_destroy(struct request_sock_queue *queue); |
Arnaldo Carvalho de Melo | 83e3609 | 2005-08-09 19:33:31 -0700 | [diff] [blame] | 169 | extern void reqsk_queue_destroy(struct request_sock_queue *queue); |
Jerry Chu | 1046716 | 2012-08-31 12:29:11 +0000 | [diff] [blame] | 170 | extern void reqsk_fastopen_remove(struct sock *sk, |
| 171 | struct request_sock *req, bool reset); |
Arnaldo Carvalho de Melo | 83e3609 | 2005-08-09 19:33:31 -0700 | [diff] [blame] | 172 | |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 173 | static inline struct request_sock * |
| 174 | reqsk_queue_yank_acceptq(struct request_sock_queue *queue) |
| 175 | { |
| 176 | struct request_sock *req = queue->rskq_accept_head; |
| 177 | |
Norbert Kiesel | 3eb4801 | 2006-03-26 17:39:55 -0800 | [diff] [blame] | 178 | queue->rskq_accept_head = NULL; |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 179 | return req; |
| 180 | } |
| 181 | |
| 182 | static inline int reqsk_queue_empty(struct request_sock_queue *queue) |
| 183 | { |
| 184 | return queue->rskq_accept_head == NULL; |
| 185 | } |
| 186 | |
| 187 | static inline void reqsk_queue_unlink(struct request_sock_queue *queue, |
| 188 | struct request_sock *req, |
| 189 | struct request_sock **prev_req) |
| 190 | { |
| 191 | write_lock(&queue->syn_wait_lock); |
| 192 | *prev_req = req->dl_next; |
| 193 | write_unlock(&queue->syn_wait_lock); |
| 194 | } |
| 195 | |
| 196 | static inline void reqsk_queue_add(struct request_sock_queue *queue, |
| 197 | struct request_sock *req, |
| 198 | struct sock *parent, |
| 199 | struct sock *child) |
| 200 | { |
| 201 | req->sk = child; |
| 202 | sk_acceptq_added(parent); |
| 203 | |
| 204 | if (queue->rskq_accept_head == NULL) |
| 205 | queue->rskq_accept_head = req; |
| 206 | else |
| 207 | queue->rskq_accept_tail->dl_next = req; |
| 208 | |
| 209 | queue->rskq_accept_tail = req; |
| 210 | req->dl_next = NULL; |
| 211 | } |
| 212 | |
| 213 | static inline struct request_sock *reqsk_queue_remove(struct request_sock_queue *queue) |
| 214 | { |
| 215 | struct request_sock *req = queue->rskq_accept_head; |
| 216 | |
Ilpo Järvinen | 547b792 | 2008-07-25 21:43:18 -0700 | [diff] [blame] | 217 | WARN_ON(req == NULL); |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 218 | |
| 219 | queue->rskq_accept_head = req->dl_next; |
| 220 | if (queue->rskq_accept_head == NULL) |
| 221 | queue->rskq_accept_tail = NULL; |
| 222 | |
| 223 | return req; |
| 224 | } |
| 225 | |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 226 | static inline int reqsk_queue_removed(struct request_sock_queue *queue, |
| 227 | struct request_sock *req) |
| 228 | { |
Arnaldo Carvalho de Melo | 2ad69c5 | 2005-06-18 22:48:55 -0700 | [diff] [blame] | 229 | struct listen_sock *lopt = queue->listen_opt; |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 230 | |
Eric Dumazet | e6c022a | 2012-10-27 23:16:46 +0000 | [diff] [blame] | 231 | if (req->num_timeout == 0) |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 232 | --lopt->qlen_young; |
| 233 | |
| 234 | return --lopt->qlen; |
| 235 | } |
| 236 | |
| 237 | static inline int reqsk_queue_added(struct request_sock_queue *queue) |
| 238 | { |
Arnaldo Carvalho de Melo | 2ad69c5 | 2005-06-18 22:48:55 -0700 | [diff] [blame] | 239 | struct listen_sock *lopt = queue->listen_opt; |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 240 | const int prev_qlen = lopt->qlen; |
| 241 | |
| 242 | lopt->qlen_young++; |
| 243 | lopt->qlen++; |
| 244 | return prev_qlen; |
| 245 | } |
| 246 | |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 247 | static inline int reqsk_queue_len(const struct request_sock_queue *queue) |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 248 | { |
| 249 | return queue->listen_opt != NULL ? queue->listen_opt->qlen : 0; |
| 250 | } |
| 251 | |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 252 | static inline int reqsk_queue_len_young(const struct request_sock_queue *queue) |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 253 | { |
| 254 | return queue->listen_opt->qlen_young; |
| 255 | } |
| 256 | |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 257 | static inline int reqsk_queue_is_full(const struct request_sock_queue *queue) |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 258 | { |
| 259 | return queue->listen_opt->qlen >> queue->listen_opt->max_qlen_log; |
| 260 | } |
| 261 | |
| 262 | static inline void reqsk_queue_hash_req(struct request_sock_queue *queue, |
| 263 | u32 hash, struct request_sock *req, |
Arnaldo Carvalho de Melo | 8129765 | 2005-12-13 23:15:24 -0800 | [diff] [blame] | 264 | unsigned long timeout) |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 265 | { |
Arnaldo Carvalho de Melo | 2ad69c5 | 2005-06-18 22:48:55 -0700 | [diff] [blame] | 266 | struct listen_sock *lopt = queue->listen_opt; |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 267 | |
| 268 | req->expires = jiffies + timeout; |
Eric Dumazet | e6c022a | 2012-10-27 23:16:46 +0000 | [diff] [blame] | 269 | req->num_retrans = 0; |
| 270 | req->num_timeout = 0; |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 271 | req->sk = NULL; |
| 272 | req->dl_next = lopt->syn_table[hash]; |
| 273 | |
| 274 | write_lock(&queue->syn_wait_lock); |
| 275 | lopt->syn_table[hash] = req; |
| 276 | write_unlock(&queue->syn_wait_lock); |
| 277 | } |
| 278 | |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 279 | #endif /* _REQUEST_SOCK_H */ |