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; |
Eric Dumazet | ea3bea3 | 2015-09-25 07:39:23 -0700 | [diff] [blame] | 35 | int (*rtx_syn_ack)(const struct sock *sk, |
Christoph Paasch | 1a2c618 | 2013-03-17 08:23:34 +0000 | [diff] [blame] | 36 | struct request_sock *req); |
Eric Dumazet | a00e744 | 2015-09-29 07:42:39 -0700 | [diff] [blame] | 37 | void (*send_ack)(const 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); |
Eric Dumazet | a00e744 | 2015-09-29 07:42:39 -0700 | [diff] [blame] | 39 | void (*send_reset)(const struct sock *sk, |
YOSHIFUJI Hideaki | cfb6eeb | 2006-11-14 19:07:45 -0800 | [diff] [blame] | 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); |
Eric Dumazet | 42cb80a | 2015-03-22 10:22:19 -0700 | [diff] [blame] | 42 | void (*syn_ack_timeout)(const struct request_sock *req); |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 43 | }; |
| 44 | |
Eric Dumazet | 1b70e97 | 2015-09-25 07:39:24 -0700 | [diff] [blame] | 45 | int inet_rtx_syn_ack(const struct sock *parent, struct request_sock *req); |
Eric Dumazet | e6c022a | 2012-10-27 23:16:46 +0000 | [diff] [blame] | 46 | |
Arnaldo Carvalho de Melo | 60236fd | 2005-06-18 22:47:21 -0700 | [diff] [blame] | 47 | /* struct request_sock - mini sock to represent a connection request |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 48 | */ |
Arnaldo Carvalho de Melo | 60236fd | 2005-06-18 22:47:21 -0700 | [diff] [blame] | 49 | struct request_sock { |
Eric Dumazet | 634fb979 | 2013-10-09 15:21:29 -0700 | [diff] [blame] | 50 | struct sock_common __req_common; |
Eric Dumazet | 1e2e011 | 2015-03-12 16:44:06 -0700 | [diff] [blame] | 51 | #define rsk_refcnt __req_common.skc_refcnt |
Eric Dumazet | 52452c5 | 2015-03-19 19:04:19 -0700 | [diff] [blame] | 52 | #define rsk_hash __req_common.skc_hash |
Eric Dumazet | 1e2e011 | 2015-03-12 16:44:06 -0700 | [diff] [blame] | 53 | |
Eric Dumazet | 3fb62c5 | 2013-04-19 14:29:25 -0700 | [diff] [blame] | 54 | struct request_sock *dl_next; |
Eric Dumazet | 4e9a578 | 2015-03-17 18:32:28 -0700 | [diff] [blame] | 55 | struct sock *rsk_listener; |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 56 | u16 mss; |
Eric Dumazet | e6c022a | 2012-10-27 23:16:46 +0000 | [diff] [blame] | 57 | u8 num_retrans; /* number of retransmits */ |
| 58 | u8 cookie_ts:1; /* syncookie: encode tcpopts in timestamp */ |
| 59 | u8 num_timeout:7; /* number of timeouts */ |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 60 | /* The following two fields can be easily recomputed I think -AK */ |
| 61 | u32 window_clamp; /* window clamp at creation time */ |
| 62 | u32 rcv_wnd; /* rcv_wnd offered first time */ |
| 63 | u32 ts_recent; |
Eric Dumazet | fa76ce73 | 2015-03-19 19:04:20 -0700 | [diff] [blame] | 64 | struct timer_list rsk_timer; |
Eric Dumazet | 72a3eff | 2006-11-16 02:30:37 -0800 | [diff] [blame] | 65 | const struct request_sock_ops *rsk_ops; |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 66 | struct sock *sk; |
Eric Dumazet | cd8ae85 | 2015-05-03 21:34:46 -0700 | [diff] [blame] | 67 | u32 *saved_syn; |
Venkat Yekkirala | 4237c75 | 2006-07-24 23:32:50 -0700 | [diff] [blame] | 68 | u32 secid; |
Venkat Yekkirala | 6b87769 | 2006-11-08 17:04:09 -0600 | [diff] [blame] | 69 | u32 peer_secid; |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 70 | }; |
| 71 | |
Eric Dumazet | b267cdd | 2015-10-02 11:43:27 -0700 | [diff] [blame] | 72 | static inline struct request_sock *inet_reqsk(struct sock *sk) |
| 73 | { |
| 74 | return (struct request_sock *)sk; |
| 75 | } |
| 76 | |
| 77 | static inline struct sock *req_to_sk(struct request_sock *req) |
| 78 | { |
| 79 | return (struct sock *)req; |
| 80 | } |
| 81 | |
Eric Dumazet | 4e9a578 | 2015-03-17 18:32:28 -0700 | [diff] [blame] | 82 | static inline struct request_sock * |
Eric Dumazet | a1a5344 | 2015-10-04 21:08:11 -0700 | [diff] [blame] | 83 | reqsk_alloc(const struct request_sock_ops *ops, struct sock *sk_listener, |
| 84 | bool attach_listener) |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 85 | { |
Eric Dumazet | e96f78a | 2015-10-03 06:27:28 -0700 | [diff] [blame] | 86 | struct request_sock *req; |
| 87 | |
| 88 | req = kmem_cache_alloc(ops->slab, GFP_ATOMIC | __GFP_NOWARN); |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 89 | |
Eric Dumazet | 4e9a578 | 2015-03-17 18:32:28 -0700 | [diff] [blame] | 90 | if (req) { |
Arnaldo Carvalho de Melo | 60236fd | 2005-06-18 22:47:21 -0700 | [diff] [blame] | 91 | req->rsk_ops = ops; |
Eric Dumazet | a1a5344 | 2015-10-04 21:08:11 -0700 | [diff] [blame] | 92 | if (attach_listener) { |
| 93 | sock_hold(sk_listener); |
| 94 | req->rsk_listener = sk_listener; |
| 95 | } else { |
| 96 | req->rsk_listener = NULL; |
| 97 | } |
Eric Dumazet | b267cdd | 2015-10-02 11:43:27 -0700 | [diff] [blame] | 98 | req_to_sk(req)->sk_prot = sk_listener->sk_prot; |
| 99 | sk_node_init(&req_to_sk(req)->sk_node); |
Eric Dumazet | 004a5d0 | 2015-10-04 21:08:10 -0700 | [diff] [blame] | 100 | sk_tx_queue_clear(req_to_sk(req)); |
Eric Dumazet | cd8ae85 | 2015-05-03 21:34:46 -0700 | [diff] [blame] | 101 | req->saved_syn = NULL; |
Eric Dumazet | 0470c8c | 2015-03-17 18:32:31 -0700 | [diff] [blame] | 102 | /* Following is temporary. It is coupled with debugging |
| 103 | * helpers in reqsk_put() & reqsk_free() |
| 104 | */ |
| 105 | atomic_set(&req->rsk_refcnt, 0); |
Eric Dumazet | 4e9a578 | 2015-03-17 18:32:28 -0700 | [diff] [blame] | 106 | } |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 107 | return req; |
| 108 | } |
| 109 | |
Arnaldo Carvalho de Melo | 60236fd | 2005-06-18 22:47:21 -0700 | [diff] [blame] | 110 | static inline void reqsk_free(struct request_sock *req) |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 111 | { |
Eric Dumazet | 13854e5 | 2015-03-15 21:12:16 -0700 | [diff] [blame] | 112 | /* temporary debugging */ |
| 113 | WARN_ON_ONCE(atomic_read(&req->rsk_refcnt) != 0); |
| 114 | |
Arnaldo Carvalho de Melo | 60236fd | 2005-06-18 22:47:21 -0700 | [diff] [blame] | 115 | req->rsk_ops->destructor(req); |
Eric Dumazet | 4e9a578 | 2015-03-17 18:32:28 -0700 | [diff] [blame] | 116 | if (req->rsk_listener) |
| 117 | sock_put(req->rsk_listener); |
Eric Dumazet | cd8ae85 | 2015-05-03 21:34:46 -0700 | [diff] [blame] | 118 | kfree(req->saved_syn); |
Eric Dumazet | 13854e5 | 2015-03-15 21:12:16 -0700 | [diff] [blame] | 119 | kmem_cache_free(req->rsk_ops->slab, req); |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 120 | } |
| 121 | |
Eric Dumazet | 1e2e011 | 2015-03-12 16:44:06 -0700 | [diff] [blame] | 122 | static inline void reqsk_put(struct request_sock *req) |
| 123 | { |
| 124 | if (atomic_dec_and_test(&req->rsk_refcnt)) |
| 125 | reqsk_free(req); |
| 126 | } |
| 127 | |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 128 | extern int sysctl_max_syn_backlog; |
| 129 | |
Jerry Chu | 1046716 | 2012-08-31 12:29:11 +0000 | [diff] [blame] | 130 | /* |
| 131 | * For a TCP Fast Open listener - |
| 132 | * lock - protects the access to all the reqsk, which is co-owned by |
| 133 | * the listener and the child socket. |
| 134 | * qlen - pending TFO requests (still in TCP_SYN_RECV). |
| 135 | * max_qlen - max TFO reqs allowed before TFO is disabled. |
| 136 | * |
| 137 | * XXX (TFO) - ideally these fields can be made as part of "listen_sock" |
| 138 | * structure above. But there is some implementation difficulty due to |
| 139 | * listen_sock being part of request_sock_queue hence will be freed when |
| 140 | * a listener is stopped. But TFO related fields may continue to be |
| 141 | * accessed even after a listener is closed, until its sk_refcnt drops |
| 142 | * to 0 implying no more outstanding TFO reqs. One solution is to keep |
| 143 | * listen_opt around until sk_refcnt drops to 0. But there is some other |
| 144 | * complexity that needs to be resolved. E.g., a listener can be disabled |
| 145 | * temporarily through shutdown()->tcp_disconnect(), and re-enabled later. |
| 146 | */ |
| 147 | struct fastopen_queue { |
| 148 | struct request_sock *rskq_rst_head; /* Keep track of past TFO */ |
| 149 | struct request_sock *rskq_rst_tail; /* requests that caused RST. |
| 150 | * This is part of the defense |
| 151 | * against spoofing attack. |
| 152 | */ |
| 153 | spinlock_t lock; |
| 154 | int qlen; /* # of pending (TCP_SYN_RECV) reqs */ |
| 155 | int max_qlen; /* != 0 iff TFO is currently enabled */ |
| 156 | }; |
| 157 | |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 158 | /** struct request_sock_queue - queue of request_socks |
| 159 | * |
| 160 | * @rskq_accept_head - FIFO head of established children |
| 161 | * @rskq_accept_tail - FIFO tail of established children |
Arnaldo Carvalho de Melo | 295f732 | 2005-08-09 20:11:56 -0700 | [diff] [blame] | 162 | * @rskq_defer_accept - User waits for some data after accept() |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 163 | * |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 164 | */ |
| 165 | struct request_sock_queue { |
Eric Dumazet | fff1f30 | 2015-10-02 11:43:23 -0700 | [diff] [blame] | 166 | spinlock_t rskq_lock; |
| 167 | u8 rskq_defer_accept; |
Eric Dumazet | ef547f2 | 2015-10-02 11:43:37 -0700 | [diff] [blame] | 168 | |
Eric Dumazet | 8d2675f | 2015-10-02 11:43:25 -0700 | [diff] [blame] | 169 | u32 synflood_warned; |
Eric Dumazet | aac065c | 2015-10-02 11:43:24 -0700 | [diff] [blame] | 170 | atomic_t qlen; |
| 171 | atomic_t young; |
| 172 | |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 173 | struct request_sock *rskq_accept_head; |
| 174 | struct request_sock *rskq_accept_tail; |
Eric Dumazet | 0536fcc | 2015-09-29 07:42:52 -0700 | [diff] [blame] | 175 | struct fastopen_queue fastopenq; /* Check max_qlen != 0 to determine |
| 176 | * if TFO is enabled. |
Jerry Chu | 1046716 | 2012-08-31 12:29:11 +0000 | [diff] [blame] | 177 | */ |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 178 | }; |
| 179 | |
Eric Dumazet | ef547f2 | 2015-10-02 11:43:37 -0700 | [diff] [blame] | 180 | void reqsk_queue_alloc(struct request_sock_queue *queue); |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 181 | |
Joe Perches | c0f4502 | 2013-09-22 10:32:20 -0700 | [diff] [blame] | 182 | void reqsk_fastopen_remove(struct sock *sk, struct request_sock *req, |
| 183 | bool reset); |
Arnaldo Carvalho de Melo | 83e3609 | 2005-08-09 19:33:31 -0700 | [diff] [blame] | 184 | |
Eric Dumazet | fff1f30 | 2015-10-02 11:43:23 -0700 | [diff] [blame] | 185 | static inline bool reqsk_queue_empty(const struct request_sock_queue *queue) |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 186 | { |
| 187 | return queue->rskq_accept_head == NULL; |
| 188 | } |
| 189 | |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 190 | static inline void reqsk_queue_add(struct request_sock_queue *queue, |
| 191 | struct request_sock *req, |
| 192 | struct sock *parent, |
| 193 | struct sock *child) |
| 194 | { |
Eric Dumazet | fff1f30 | 2015-10-02 11:43:23 -0700 | [diff] [blame] | 195 | spin_lock(&queue->rskq_lock); |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 196 | req->sk = child; |
| 197 | sk_acceptq_added(parent); |
| 198 | |
| 199 | if (queue->rskq_accept_head == NULL) |
| 200 | queue->rskq_accept_head = req; |
| 201 | else |
| 202 | queue->rskq_accept_tail->dl_next = req; |
| 203 | |
| 204 | queue->rskq_accept_tail = req; |
| 205 | req->dl_next = NULL; |
Eric Dumazet | fff1f30 | 2015-10-02 11:43:23 -0700 | [diff] [blame] | 206 | spin_unlock(&queue->rskq_lock); |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 207 | } |
| 208 | |
Eric Dumazet | fff1f30 | 2015-10-02 11:43:23 -0700 | [diff] [blame] | 209 | static inline struct request_sock *reqsk_queue_remove(struct request_sock_queue *queue, |
| 210 | struct sock *parent) |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 211 | { |
Eric Dumazet | fff1f30 | 2015-10-02 11:43:23 -0700 | [diff] [blame] | 212 | struct request_sock *req; |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 213 | |
Eric Dumazet | fff1f30 | 2015-10-02 11:43:23 -0700 | [diff] [blame] | 214 | spin_lock_bh(&queue->rskq_lock); |
| 215 | req = queue->rskq_accept_head; |
| 216 | if (req) { |
| 217 | sk_acceptq_removed(parent); |
| 218 | queue->rskq_accept_head = req->dl_next; |
| 219 | if (queue->rskq_accept_head == NULL) |
| 220 | queue->rskq_accept_tail = NULL; |
| 221 | } |
| 222 | spin_unlock_bh(&queue->rskq_lock); |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 223 | return req; |
| 224 | } |
| 225 | |
Eric Dumazet | fa76ce73 | 2015-03-19 19:04:20 -0700 | [diff] [blame] | 226 | static inline void reqsk_queue_removed(struct request_sock_queue *queue, |
| 227 | const struct request_sock *req) |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 228 | { |
Eric Dumazet | e6c022a | 2012-10-27 23:16:46 +0000 | [diff] [blame] | 229 | if (req->num_timeout == 0) |
Eric Dumazet | aac065c | 2015-10-02 11:43:24 -0700 | [diff] [blame] | 230 | atomic_dec(&queue->young); |
| 231 | atomic_dec(&queue->qlen); |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 232 | } |
| 233 | |
Eric Dumazet | fa76ce73 | 2015-03-19 19:04:20 -0700 | [diff] [blame] | 234 | static inline void reqsk_queue_added(struct request_sock_queue *queue) |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 235 | { |
Eric Dumazet | aac065c | 2015-10-02 11:43:24 -0700 | [diff] [blame] | 236 | atomic_inc(&queue->young); |
| 237 | atomic_inc(&queue->qlen); |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 238 | } |
| 239 | |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 240 | 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] | 241 | { |
Eric Dumazet | aac065c | 2015-10-02 11:43:24 -0700 | [diff] [blame] | 242 | return atomic_read(&queue->qlen); |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 243 | } |
| 244 | |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 245 | 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] | 246 | { |
Eric Dumazet | aac065c | 2015-10-02 11:43:24 -0700 | [diff] [blame] | 247 | return atomic_read(&queue->young); |
Arnaldo Carvalho de Melo | 0e87506 | 2005-06-18 22:47:59 -0700 | [diff] [blame] | 248 | } |
| 249 | |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 250 | #endif /* _REQUEST_SOCK_H */ |