Linux kernel mirror (for testing)
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1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * NET Generic infrastructure for INET connection oriented protocols.
4 *
5 * Definitions for inet_connection_sock
6 *
7 * Authors: Many people, see the TCP sources
8 *
9 * From code originally in TCP
10 */
11#ifndef _INET_CONNECTION_SOCK_H
12#define _INET_CONNECTION_SOCK_H
13
14#include <linux/compiler.h>
15#include <linux/string.h>
16#include <linux/timer.h>
17#include <linux/poll.h>
18#include <linux/kernel.h>
19#include <linux/sockptr.h>
20
21#include <net/inet_sock.h>
22#include <net/request_sock.h>
23
24/* Cancel timers, when they are not required. */
25#undef INET_CSK_CLEAR_TIMERS
26
27struct inet_bind_bucket;
28struct inet_bind2_bucket;
29struct tcp_congestion_ops;
30
31/*
32 * Pointers to address related TCP functions
33 * (i.e. things that depend on the address family)
34 */
35struct inet_connection_sock_af_ops {
36 int (*queue_xmit)(struct sock *sk, struct sk_buff *skb, struct flowi *fl);
37 void (*send_check)(struct sock *sk, struct sk_buff *skb);
38 int (*rebuild_header)(struct sock *sk);
39 void (*sk_rx_dst_set)(struct sock *sk, const struct sk_buff *skb);
40 int (*conn_request)(struct sock *sk, struct sk_buff *skb);
41 struct sock *(*syn_recv_sock)(const struct sock *sk, struct sk_buff *skb,
42 struct request_sock *req,
43 struct dst_entry *dst,
44 struct request_sock *req_unhash,
45 bool *own_req,
46 void (*opt_child_init)(struct sock *newsk,
47 const struct sock *sk));
48 u16 net_header_len;
49 int (*setsockopt)(struct sock *sk, int level, int optname,
50 sockptr_t optval, unsigned int optlen);
51 int (*getsockopt)(struct sock *sk, int level, int optname,
52 char __user *optval, int __user *optlen);
53 void (*mtu_reduced)(struct sock *sk);
54};
55
56/** inet_connection_sock - INET connection oriented sock
57 *
58 * @icsk_accept_queue: FIFO of established children
59 * @icsk_bind_hash: Bind node
60 * @icsk_bind2_hash: Bind node in the bhash2 table
61 * @icsk_delack_timer: Delayed ACK timer
62 * @icsk_keepalive_timer: Keepalive timer
63 * @mptcp_tout_timer: mptcp timer
64 * @icsk_rto: Retransmit timeout
65 * @icsk_pmtu_cookie Last pmtu seen by socket
66 * @icsk_ca_ops Pluggable congestion control hook
67 * @icsk_af_ops Operations which are AF_INET{4,6} specific
68 * @icsk_ulp_ops Pluggable ULP control hook
69 * @icsk_ulp_data ULP private data
70 * @icsk_ca_state: Congestion control state
71 * @icsk_retransmits: Number of unrecovered [RTO] timeouts
72 * @icsk_pending: Scheduled timer event
73 * @icsk_backoff: Backoff
74 * @icsk_syn_retries: Number of allowed SYN (or equivalent) retries
75 * @icsk_probes_out: unanswered 0 window probes
76 * @icsk_ext_hdr_len: Network protocol overhead (IP/IPv6 options)
77 * @icsk_ack: Delayed ACK control data
78 * @icsk_mtup; MTU probing control data
79 * @icsk_probes_tstamp: Probe timestamp (cleared by non-zero window ack)
80 * @icsk_user_timeout: TCP_USER_TIMEOUT value
81 */
82struct inet_connection_sock {
83 /* inet_sock has to be the first member! */
84 struct inet_sock icsk_inet;
85 struct request_sock_queue icsk_accept_queue;
86 struct inet_bind_bucket *icsk_bind_hash;
87 struct inet_bind2_bucket *icsk_bind2_hash;
88 struct timer_list icsk_delack_timer;
89 union {
90 struct timer_list icsk_keepalive_timer;
91 struct timer_list mptcp_tout_timer;
92 };
93 __u32 icsk_rto;
94 __u32 icsk_rto_min;
95 u32 icsk_rto_max;
96 __u32 icsk_delack_max;
97 __u32 icsk_pmtu_cookie;
98 const struct tcp_congestion_ops *icsk_ca_ops;
99 const struct inet_connection_sock_af_ops *icsk_af_ops;
100 const struct tcp_ulp_ops *icsk_ulp_ops;
101 void __rcu *icsk_ulp_data;
102 unsigned int (*icsk_sync_mss)(struct sock *sk, u32 pmtu);
103 __u8 icsk_ca_state:5,
104 icsk_ca_initialized:1,
105 icsk_ca_setsockopt:1,
106 icsk_ca_dst_locked:1;
107 __u8 icsk_retransmits;
108 __u8 icsk_pending;
109 __u8 icsk_backoff;
110 __u8 icsk_syn_retries;
111 __u8 icsk_probes_out;
112 __u16 icsk_ext_hdr_len;
113 struct {
114 __u8 pending; /* ACK is pending */
115 __u8 quick; /* Scheduled number of quick acks */
116 __u8 pingpong; /* The session is interactive */
117 __u8 retry; /* Number of attempts */
118 #define ATO_BITS 8
119 __u32 ato:ATO_BITS, /* Predicted tick of soft clock */
120 lrcv_flowlabel:20, /* last received ipv6 flowlabel */
121 dst_quick_ack:1, /* cache dst RTAX_QUICKACK */
122 unused:3;
123 __u32 lrcvtime; /* timestamp of last received data packet */
124 __u16 last_seg_size; /* Size of last incoming segment */
125 __u16 rcv_mss; /* MSS used for delayed ACK decisions */
126 } icsk_ack;
127 struct {
128 /* Range of MTUs to search */
129 int search_high;
130 int search_low;
131
132 /* Information on the current probe. */
133 u32 probe_size:31,
134 /* Is the MTUP feature enabled for this connection? */
135 enabled:1;
136
137 u32 probe_timestamp;
138 } icsk_mtup;
139 u32 icsk_probes_tstamp;
140 u32 icsk_user_timeout;
141
142 u64 icsk_ca_priv[104 / sizeof(u64)];
143#define ICSK_CA_PRIV_SIZE sizeof_field(struct inet_connection_sock, icsk_ca_priv)
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_LOSS_PROBE 5 /* Tail loss probe timer */
150#define ICSK_TIME_REO_TIMEOUT 6 /* Reordering timer */
151
152#define inet_csk(ptr) container_of_const(ptr, struct inet_connection_sock, icsk_inet.sk)
153
154static inline void *inet_csk_ca(const struct sock *sk)
155{
156 return (void *)inet_csk(sk)->icsk_ca_priv;
157}
158
159struct sock *inet_csk_clone_lock(const struct sock *sk,
160 const struct request_sock *req,
161 const gfp_t priority);
162
163enum inet_csk_ack_state_t {
164 ICSK_ACK_SCHED = 1,
165 ICSK_ACK_TIMER = 2,
166 ICSK_ACK_PUSHED = 4,
167 ICSK_ACK_PUSHED2 = 8,
168 ICSK_ACK_NOW = 16, /* Send the next ACK immediately (once) */
169 ICSK_ACK_NOMEM = 32,
170};
171
172void inet_csk_init_xmit_timers(struct sock *sk,
173 void (*retransmit_handler)(struct timer_list *),
174 void (*delack_handler)(struct timer_list *),
175 void (*keepalive_handler)(struct timer_list *));
176void inet_csk_clear_xmit_timers(struct sock *sk);
177void inet_csk_clear_xmit_timers_sync(struct sock *sk);
178
179static inline void inet_csk_schedule_ack(struct sock *sk)
180{
181 inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED;
182}
183
184static inline int inet_csk_ack_scheduled(const struct sock *sk)
185{
186 return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED;
187}
188
189static inline void inet_csk_delack_init(struct sock *sk)
190{
191 memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack));
192}
193
194static inline unsigned long tcp_timeout_expires(const struct sock *sk)
195{
196 return READ_ONCE(sk->tcp_retransmit_timer.expires);
197}
198
199static inline unsigned long
200icsk_delack_timeout(const struct inet_connection_sock *icsk)
201{
202 return READ_ONCE(icsk->icsk_delack_timer.expires);
203}
204
205static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what)
206{
207 struct inet_connection_sock *icsk = inet_csk(sk);
208
209 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
210 smp_store_release(&icsk->icsk_pending, 0);
211#ifdef INET_CSK_CLEAR_TIMERS
212 sk_stop_timer(sk, &sk->tcp_retransmit_timer);
213#endif
214 } else if (what == ICSK_TIME_DACK) {
215 smp_store_release(&icsk->icsk_ack.pending, 0);
216 icsk->icsk_ack.retry = 0;
217#ifdef INET_CSK_CLEAR_TIMERS
218 sk_stop_timer(sk, &icsk->icsk_delack_timer);
219#endif
220 } else {
221 pr_debug("inet_csk BUG: unknown timer value\n");
222 }
223}
224
225/*
226 * Reset the retransmission timer
227 */
228static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what,
229 unsigned long when,
230 const unsigned long max_when)
231{
232 struct inet_connection_sock *icsk = inet_csk(sk);
233
234 if (when > max_when) {
235 pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n",
236 sk, what, when, (void *)_THIS_IP_);
237 when = max_when;
238 }
239
240 when += jiffies;
241 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0 ||
242 what == ICSK_TIME_LOSS_PROBE || what == ICSK_TIME_REO_TIMEOUT) {
243 smp_store_release(&icsk->icsk_pending, what);
244 sk_reset_timer(sk, &sk->tcp_retransmit_timer, when);
245 } else if (what == ICSK_TIME_DACK) {
246 smp_store_release(&icsk->icsk_ack.pending,
247 icsk->icsk_ack.pending | ICSK_ACK_TIMER);
248 sk_reset_timer(sk, &icsk->icsk_delack_timer, when);
249 } else {
250 pr_debug("inet_csk BUG: unknown timer value\n");
251 }
252}
253
254static inline unsigned long
255inet_csk_rto_backoff(const struct inet_connection_sock *icsk,
256 unsigned long max_when)
257{
258 u64 when = (u64)icsk->icsk_rto << icsk->icsk_backoff;
259
260 return (unsigned long)min_t(u64, when, max_when);
261}
262
263struct sock *inet_csk_accept(struct sock *sk, struct proto_accept_arg *arg);
264
265int inet_csk_get_port(struct sock *sk, unsigned short snum);
266
267struct dst_entry *inet_csk_route_req(const struct sock *sk, struct flowi4 *fl4,
268 const struct request_sock *req);
269struct dst_entry *inet_csk_route_child_sock(const struct sock *sk,
270 struct sock *newsk,
271 const struct request_sock *req);
272
273struct sock *inet_csk_reqsk_queue_add(struct sock *sk,
274 struct request_sock *req,
275 struct sock *child);
276bool inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req);
277struct sock *inet_csk_complete_hashdance(struct sock *sk, struct sock *child,
278 struct request_sock *req,
279 bool own_req);
280
281static inline void inet_csk_reqsk_queue_added(struct sock *sk)
282{
283 reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue);
284}
285
286static inline int inet_csk_reqsk_queue_len(const struct sock *sk)
287{
288 return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue);
289}
290
291static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk)
292{
293 return inet_csk_reqsk_queue_len(sk) > READ_ONCE(sk->sk_max_ack_backlog);
294}
295
296bool inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req);
297void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req);
298
299void inet_csk_destroy_sock(struct sock *sk);
300void inet_csk_prepare_for_destroy_sock(struct sock *sk);
301void inet_csk_prepare_forced_close(struct sock *sk);
302
303/*
304 * LISTEN is a special case for poll..
305 */
306static inline __poll_t inet_csk_listen_poll(const struct sock *sk)
307{
308 return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ?
309 (EPOLLIN | EPOLLRDNORM) : 0;
310}
311
312int inet_csk_listen_start(struct sock *sk);
313void inet_csk_listen_stop(struct sock *sk);
314
315/* update the fast reuse flag when adding a socket */
316void inet_csk_update_fastreuse(const struct sock *sk,
317 struct inet_bind_bucket *tb,
318 struct inet_bind2_bucket *tb2);
319
320struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu);
321
322static inline void inet_csk_enter_pingpong_mode(struct sock *sk)
323{
324 inet_csk(sk)->icsk_ack.pingpong =
325 READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_pingpong_thresh);
326}
327
328static inline void inet_csk_exit_pingpong_mode(struct sock *sk)
329{
330 inet_csk(sk)->icsk_ack.pingpong = 0;
331}
332
333static inline bool inet_csk_in_pingpong_mode(struct sock *sk)
334{
335 return inet_csk(sk)->icsk_ack.pingpong >=
336 READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_pingpong_thresh);
337}
338
339static inline void inet_csk_inc_pingpong_cnt(struct sock *sk)
340{
341 struct inet_connection_sock *icsk = inet_csk(sk);
342
343 if (icsk->icsk_ack.pingpong < U8_MAX)
344 icsk->icsk_ack.pingpong++;
345}
346
347static inline bool inet_csk_has_ulp(const struct sock *sk)
348{
349 return inet_test_bit(IS_ICSK, sk) && !!inet_csk(sk)->icsk_ulp_ops;
350}
351
352static inline void inet_init_csk_locks(struct sock *sk)
353{
354 struct inet_connection_sock *icsk = inet_csk(sk);
355
356 spin_lock_init(&icsk->icsk_accept_queue.rskq_lock);
357 spin_lock_init(&icsk->icsk_accept_queue.fastopenq.lock);
358}
359
360#endif /* _INET_CONNECTION_SOCK_H */