1/*
2 * NET Generic infrastructure for INET connection oriented protocols.
3 *
4 * Definitions for inet_connection_sock
5 *
6 * Authors: Many people, see the TCP sources
7 *
8 * From code originally in TCP
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 _INET_CONNECTION_SOCK_H
16#define _INET_CONNECTION_SOCK_H
17
18#include <linux/compiler.h>
19#include <linux/string.h>
20#include <linux/timer.h>
21#include <linux/poll.h>
22#include <linux/kernel.h>
23
24#include <net/inet_sock.h>
25#include <net/request_sock.h>
26
27/* Cancel timers, when they are not required. */
28#undef INET_CSK_CLEAR_TIMERS
29
30struct inet_bind_bucket;
31struct tcp_congestion_ops;
32
33/*
34 * Pointers to address related TCP functions
35 * (i.e. things that depend on the address family)
36 */
37struct inet_connection_sock_af_ops {
38 int (*queue_xmit)(struct sock *sk, struct sk_buff *skb, struct flowi *fl);
39 void (*send_check)(struct sock *sk, struct sk_buff *skb);
40 int (*rebuild_header)(struct sock *sk);
41 void (*sk_rx_dst_set)(struct sock *sk, const struct sk_buff *skb);
42 int (*conn_request)(struct sock *sk, struct sk_buff *skb);
43 struct sock *(*syn_recv_sock)(const struct sock *sk, struct sk_buff *skb,
44 struct request_sock *req,
45 struct dst_entry *dst,
46 struct request_sock *req_unhash,
47 bool *own_req);
48 u16 net_header_len;
49 u16 net_frag_header_len;
50 u16 sockaddr_len;
51 int (*setsockopt)(struct sock *sk, int level, int optname,
52 char __user *optval, unsigned int optlen);
53 int (*getsockopt)(struct sock *sk, int level, int optname,
54 char __user *optval, int __user *optlen);
55#ifdef CONFIG_COMPAT
56 int (*compat_setsockopt)(struct sock *sk,
57 int level, int optname,
58 char __user *optval, unsigned int optlen);
59 int (*compat_getsockopt)(struct sock *sk,
60 int level, int optname,
61 char __user *optval, int __user *optlen);
62#endif
63 void (*addr2sockaddr)(struct sock *sk, struct sockaddr *);
64 void (*mtu_reduced)(struct sock *sk);
65};
66
67/** inet_connection_sock - INET connection oriented sock
68 *
69 * @icsk_accept_queue: FIFO of established children
70 * @icsk_bind_hash: Bind node
71 * @icsk_timeout: Timeout
72 * @icsk_retransmit_timer: Resend (no ack)
73 * @icsk_rto: Retransmit timeout
74 * @icsk_pmtu_cookie Last pmtu seen by socket
75 * @icsk_ca_ops Pluggable congestion control hook
76 * @icsk_af_ops Operations which are AF_INET{4,6} specific
77 * @icsk_ulp_ops Pluggable ULP control hook
78 * @icsk_ulp_data ULP private data
79 * @icsk_clean_acked Clean acked data hook
80 * @icsk_listen_portaddr_node hash to the portaddr listener hashtable
81 * @icsk_ca_state: Congestion control state
82 * @icsk_retransmits: Number of unrecovered [RTO] timeouts
83 * @icsk_pending: Scheduled timer event
84 * @icsk_backoff: Backoff
85 * @icsk_syn_retries: Number of allowed SYN (or equivalent) retries
86 * @icsk_probes_out: unanswered 0 window probes
87 * @icsk_ext_hdr_len: Network protocol overhead (IP/IPv6 options)
88 * @icsk_ack: Delayed ACK control data
89 * @icsk_mtup; MTU probing control data
90 */
91struct inet_connection_sock {
92 /* inet_sock has to be the first member! */
93 struct inet_sock icsk_inet;
94 struct request_sock_queue icsk_accept_queue;
95 struct inet_bind_bucket *icsk_bind_hash;
96 unsigned long icsk_timeout;
97 struct timer_list icsk_retransmit_timer;
98 struct timer_list icsk_delack_timer;
99 __u32 icsk_rto;
100 __u32 icsk_pmtu_cookie;
101 const struct tcp_congestion_ops *icsk_ca_ops;
102 const struct inet_connection_sock_af_ops *icsk_af_ops;
103 const struct tcp_ulp_ops *icsk_ulp_ops;
104 void *icsk_ulp_data;
105 void (*icsk_clean_acked)(struct sock *sk, u32 acked_seq);
106 struct hlist_node icsk_listen_portaddr_node;
107 unsigned int (*icsk_sync_mss)(struct sock *sk, u32 pmtu);
108 __u8 icsk_ca_state:6,
109 icsk_ca_setsockopt:1,
110 icsk_ca_dst_locked:1;
111 __u8 icsk_retransmits;
112 __u8 icsk_pending;
113 __u8 icsk_backoff;
114 __u8 icsk_syn_retries;
115 __u8 icsk_probes_out;
116 __u16 icsk_ext_hdr_len;
117 struct {
118 __u8 pending; /* ACK is pending */
119 __u8 quick; /* Scheduled number of quick acks */
120 __u8 pingpong; /* The session is interactive */
121 __u8 blocked; /* Delayed ACK was blocked by socket lock */
122 __u32 ato; /* Predicted tick of soft clock */
123 unsigned long timeout; /* Currently scheduled timeout */
124 __u32 lrcvtime; /* timestamp of last received data packet */
125 __u16 last_seg_size; /* Size of last incoming segment */
126 __u16 rcv_mss; /* MSS used for delayed ACK decisions */
127 } icsk_ack;
128 struct {
129 int enabled;
130
131 /* Range of MTUs to search */
132 int search_high;
133 int search_low;
134
135 /* Information on the current probe. */
136 int probe_size;
137
138 u32 probe_timestamp;
139 } icsk_mtup;
140 u32 icsk_user_timeout;
141
142 u64 icsk_ca_priv[104 / sizeof(u64)];
143#define ICSK_CA_PRIV_SIZE (13 * sizeof(u64))
144};
145
146#define ICSK_TIME_RETRANS 1 /* Retransmit timer */
147#define ICSK_TIME_DACK 2 /* Delayed ack timer */
148#define ICSK_TIME_PROBE0 3 /* Zero window probe timer */
149#define ICSK_TIME_EARLY_RETRANS 4 /* Early retransmit timer */
150#define ICSK_TIME_LOSS_PROBE 5 /* Tail loss probe timer */
151#define ICSK_TIME_REO_TIMEOUT 6 /* Reordering timer */
152
153static inline struct inet_connection_sock *inet_csk(const struct sock *sk)
154{
155 return (struct inet_connection_sock *)sk;
156}
157
158static inline void *inet_csk_ca(const struct sock *sk)
159{
160 return (void *)inet_csk(sk)->icsk_ca_priv;
161}
162
163struct sock *inet_csk_clone_lock(const struct sock *sk,
164 const struct request_sock *req,
165 const gfp_t priority);
166
167enum inet_csk_ack_state_t {
168 ICSK_ACK_SCHED = 1,
169 ICSK_ACK_TIMER = 2,
170 ICSK_ACK_PUSHED = 4,
171 ICSK_ACK_PUSHED2 = 8,
172 ICSK_ACK_NOW = 16 /* Send the next ACK immediately (once) */
173};
174
175void inet_csk_init_xmit_timers(struct sock *sk,
176 void (*retransmit_handler)(struct timer_list *),
177 void (*delack_handler)(struct timer_list *),
178 void (*keepalive_handler)(struct timer_list *));
179void inet_csk_clear_xmit_timers(struct sock *sk);
180
181static inline void inet_csk_schedule_ack(struct sock *sk)
182{
183 inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED;
184}
185
186static inline int inet_csk_ack_scheduled(const struct sock *sk)
187{
188 return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED;
189}
190
191static inline void inet_csk_delack_init(struct sock *sk)
192{
193 memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack));
194}
195
196void inet_csk_delete_keepalive_timer(struct sock *sk);
197void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout);
198
199static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what)
200{
201 struct inet_connection_sock *icsk = inet_csk(sk);
202
203 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
204 icsk->icsk_pending = 0;
205#ifdef INET_CSK_CLEAR_TIMERS
206 sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
207#endif
208 } else if (what == ICSK_TIME_DACK) {
209 icsk->icsk_ack.blocked = icsk->icsk_ack.pending = 0;
210#ifdef INET_CSK_CLEAR_TIMERS
211 sk_stop_timer(sk, &icsk->icsk_delack_timer);
212#endif
213 } else {
214 pr_debug("inet_csk BUG: unknown timer value\n");
215 }
216}
217
218/*
219 * Reset the retransmission timer
220 */
221static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what,
222 unsigned long when,
223 const unsigned long max_when)
224{
225 struct inet_connection_sock *icsk = inet_csk(sk);
226
227 if (when > max_when) {
228 pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n",
229 sk, what, when, (void *)_THIS_IP_);
230 when = max_when;
231 }
232
233 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0 ||
234 what == ICSK_TIME_EARLY_RETRANS || what == ICSK_TIME_LOSS_PROBE ||
235 what == ICSK_TIME_REO_TIMEOUT) {
236 icsk->icsk_pending = what;
237 icsk->icsk_timeout = jiffies + when;
238 sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout);
239 } else if (what == ICSK_TIME_DACK) {
240 icsk->icsk_ack.pending |= ICSK_ACK_TIMER;
241 icsk->icsk_ack.timeout = jiffies + when;
242 sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout);
243 } else {
244 pr_debug("inet_csk BUG: unknown timer value\n");
245 }
246}
247
248static inline unsigned long
249inet_csk_rto_backoff(const struct inet_connection_sock *icsk,
250 unsigned long max_when)
251{
252 u64 when = (u64)icsk->icsk_rto << icsk->icsk_backoff;
253
254 return (unsigned long)min_t(u64, when, max_when);
255}
256
257struct sock *inet_csk_accept(struct sock *sk, int flags, int *err, bool kern);
258
259int inet_csk_get_port(struct sock *sk, unsigned short snum);
260
261struct dst_entry *inet_csk_route_req(const struct sock *sk, struct flowi4 *fl4,
262 const struct request_sock *req);
263struct dst_entry *inet_csk_route_child_sock(const struct sock *sk,
264 struct sock *newsk,
265 const struct request_sock *req);
266
267struct sock *inet_csk_reqsk_queue_add(struct sock *sk,
268 struct request_sock *req,
269 struct sock *child);
270void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
271 unsigned long timeout);
272struct sock *inet_csk_complete_hashdance(struct sock *sk, struct sock *child,
273 struct request_sock *req,
274 bool own_req);
275
276static inline void inet_csk_reqsk_queue_added(struct sock *sk)
277{
278 reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue);
279}
280
281static inline int inet_csk_reqsk_queue_len(const struct sock *sk)
282{
283 return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue);
284}
285
286static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk)
287{
288 return inet_csk_reqsk_queue_len(sk) >= sk->sk_max_ack_backlog;
289}
290
291void inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req);
292void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req);
293
294void inet_csk_destroy_sock(struct sock *sk);
295void inet_csk_prepare_forced_close(struct sock *sk);
296
297/*
298 * LISTEN is a special case for poll..
299 */
300static inline __poll_t inet_csk_listen_poll(const struct sock *sk)
301{
302 return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ?
303 (EPOLLIN | EPOLLRDNORM) : 0;
304}
305
306int inet_csk_listen_start(struct sock *sk, int backlog);
307void inet_csk_listen_stop(struct sock *sk);
308
309void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr);
310
311int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
312 char __user *optval, int __user *optlen);
313int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
314 char __user *optval, unsigned int optlen);
315
316struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu);
317
318#define TCP_PINGPONG_THRESH 3
319
320static inline void inet_csk_enter_pingpong_mode(struct sock *sk)
321{
322 inet_csk(sk)->icsk_ack.pingpong = TCP_PINGPONG_THRESH;
323}
324
325static inline void inet_csk_exit_pingpong_mode(struct sock *sk)
326{
327 inet_csk(sk)->icsk_ack.pingpong = 0;
328}
329
330static inline bool inet_csk_in_pingpong_mode(struct sock *sk)
331{
332 return inet_csk(sk)->icsk_ack.pingpong >= TCP_PINGPONG_THRESH;
333}
334
335static inline void inet_csk_inc_pingpong_cnt(struct sock *sk)
336{
337 struct inet_connection_sock *icsk = inet_csk(sk);
338
339 if (icsk->icsk_ack.pingpong < U8_MAX)
340 icsk->icsk_ack.pingpong++;
341}
342#endif /* _INET_CONNECTION_SOCK_H */
343