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
20 #include <net/inet_sock.h>
21 #include <net/request_sock.h>
22
23 /* Cancel timers, when they are not required. */
24 #undef INET_CSK_CLEAR_TIMERS
25
26 struct inet_bind_bucket;
27 struct tcp_congestion_ops;
28
29 /*
30 * Pointers to address related TCP functions
31 * (i.e. things that depend on the address family)
32 */
33 struct inet_connection_sock_af_ops {
34 int (*queue_xmit)(struct sock *sk, struct sk_buff *skb, struct flowi *fl);
35 void (*send_check)(struct sock *sk, struct sk_buff *skb);
36 int (*rebuild_header)(struct sock *sk);
37 void (*sk_rx_dst_set)(struct sock *sk, const struct sk_buff *skb);
38 int (*conn_request)(struct sock *sk, struct sk_buff *skb);
39 struct sock *(*syn_recv_sock)(const struct sock *sk, struct sk_buff *skb,
40 struct request_sock *req,
41 struct dst_entry *dst,
42 struct request_sock *req_unhash,
43 bool *own_req);
44 u16 net_header_len;
45 u16 net_frag_header_len;
46 u16 sockaddr_len;
47 int (*setsockopt)(struct sock *sk, int level, int optname,
48 char __user *optval, unsigned int optlen);
49 int (*getsockopt)(struct sock *sk, int level, int optname,
50 char __user *optval, int __user *optlen);
51 #ifdef CONFIG_COMPAT
52 int (*compat_setsockopt)(struct sock *sk,
53 int level, int optname,
54 char __user *optval, unsigned int optlen);
55 int (*compat_getsockopt)(struct sock *sk,
56 int level, int optname,
57 char __user *optval, int __user *optlen);
58 #endif
59 void (*addr2sockaddr)(struct sock *sk, struct sockaddr *);
60 void (*mtu_reduced)(struct sock *sk);
61 };
62
63 /** inet_connection_sock - INET connection oriented sock
64 *
65 * @icsk_accept_queue: FIFO of established children
66 * @icsk_bind_hash: Bind node
67 * @icsk_timeout: Timeout
68 * @icsk_retransmit_timer: Resend (no ack)
69 * @icsk_rto: Retransmit timeout
70 * @icsk_pmtu_cookie Last pmtu seen by socket
71 * @icsk_ca_ops Pluggable congestion control hook
72 * @icsk_af_ops Operations which are AF_INET{4,6} specific
73 * @icsk_ulp_ops Pluggable ULP control hook
74 * @icsk_ulp_data ULP private data
75 * @icsk_clean_acked Clean acked data hook
76 * @icsk_listen_portaddr_node hash to the portaddr listener hashtable
77 * @icsk_ca_state: Congestion control state
78 * @icsk_retransmits: Number of unrecovered [RTO] timeouts
79 * @icsk_pending: Scheduled timer event
80 * @icsk_backoff: Backoff
81 * @icsk_syn_retries: Number of allowed SYN (or equivalent) retries
82 * @icsk_probes_out: unanswered 0 window probes
83 * @icsk_ext_hdr_len: Network protocol overhead (IP/IPv6 options)
84 * @icsk_ack: Delayed ACK control data
85 * @icsk_mtup; MTU probing control data
86 * @icsk_probes_tstamp: Probe timestamp (cleared by non-zero window ack)
87 * @icsk_user_timeout: TCP_USER_TIMEOUT value
88 */
89 struct inet_connection_sock {
90 /* inet_sock has to be the first member! */
91 struct inet_sock icsk_inet;
92 struct request_sock_queue icsk_accept_queue;
93 struct inet_bind_bucket *icsk_bind_hash;
94 unsigned long icsk_timeout;
95 struct timer_list icsk_retransmit_timer;
96 struct timer_list icsk_delack_timer;
97 __u32 icsk_rto;
98 __u32 icsk_pmtu_cookie;
99 const struct tcp_congestion_ops *icsk_ca_ops;
100 const struct inet_connection_sock_af_ops *icsk_af_ops;
101 const struct tcp_ulp_ops *icsk_ulp_ops;
102 void __rcu *icsk_ulp_data;
103 void (*icsk_clean_acked)(struct sock *sk, u32 acked_seq);
104 struct hlist_node icsk_listen_portaddr_node;
105 unsigned int (*icsk_sync_mss)(struct sock *sk, u32 pmtu);
106 __u8 icsk_ca_state:6,
107 icsk_ca_setsockopt:1,
108 icsk_ca_dst_locked:1;
109 __u8 icsk_retransmits;
110 __u8 icsk_pending;
111 __u8 icsk_backoff;
112 __u8 icsk_syn_retries;
113 __u8 icsk_probes_out;
114 __u16 icsk_ext_hdr_len;
115 struct {
116 __u8 pending; /* ACK is pending */
117 __u8 quick; /* Scheduled number of quick acks */
118 __u8 pingpong; /* The session is interactive */
119 __u8 blocked; /* Delayed ACK was blocked by socket lock */
120 __u32 ato; /* Predicted tick of soft clock */
121 unsigned long timeout; /* Currently scheduled timeout */
122 __u32 lrcvtime; /* timestamp of last received data packet */
123 __u16 last_seg_size; /* Size of last incoming segment */
124 __u16 rcv_mss; /* MSS used for delayed ACK decisions */
125 } icsk_ack;
126 #ifdef __GENKSYMS__
127 struct {
128 int enabled;
129
130 /* Range of MTUs to search */
131 int search_high;
132 int search_low;
133
134 /* Information on the current probe. */
135 int probe_size;
136
137 u32 probe_timestamp;
138 } icsk_mtup;
139 #else
140 struct {
141 /* Range of MTUs to search */
142 int search_high;
143 int search_low;
144
145 /* Information on the current probe. */
146 int enabled:1;
147 int probe_size:31;
148
149 u32 probe_timestamp;
150 } icsk_mtup;
151 u32 icsk_probes_tstamp;
152 #endif
153 u32 icsk_user_timeout;
154
155 u64 icsk_ca_priv[104 / sizeof(u64)];
156 #define ICSK_CA_PRIV_SIZE (13 * sizeof(u64))
157 };
158
159 #define ICSK_TIME_RETRANS 1 /* Retransmit timer */
160 #define ICSK_TIME_DACK 2 /* Delayed ack timer */
161 #define ICSK_TIME_PROBE0 3 /* Zero window probe timer */
162 #define ICSK_TIME_EARLY_RETRANS 4 /* Early retransmit timer */
163 #define ICSK_TIME_LOSS_PROBE 5 /* Tail loss probe timer */
164 #define ICSK_TIME_REO_TIMEOUT 6 /* Reordering timer */
165
inet_csk(const struct sock * sk)166 static inline struct inet_connection_sock *inet_csk(const struct sock *sk)
167 {
168 return (struct inet_connection_sock *)sk;
169 }
170
inet_csk_ca(const struct sock * sk)171 static inline void *inet_csk_ca(const struct sock *sk)
172 {
173 return (void *)inet_csk(sk)->icsk_ca_priv;
174 }
175
176 struct sock *inet_csk_clone_lock(const struct sock *sk,
177 const struct request_sock *req,
178 const gfp_t priority);
179
180 enum inet_csk_ack_state_t {
181 ICSK_ACK_SCHED = 1,
182 ICSK_ACK_TIMER = 2,
183 ICSK_ACK_PUSHED = 4,
184 ICSK_ACK_PUSHED2 = 8,
185 ICSK_ACK_NOW = 16 /* Send the next ACK immediately (once) */
186 };
187
188 void inet_csk_init_xmit_timers(struct sock *sk,
189 void (*retransmit_handler)(struct timer_list *),
190 void (*delack_handler)(struct timer_list *),
191 void (*keepalive_handler)(struct timer_list *));
192 void inet_csk_clear_xmit_timers(struct sock *sk);
193 void inet_csk_clear_xmit_timers_sync(struct sock *sk);
194
inet_csk_schedule_ack(struct sock * sk)195 static inline void inet_csk_schedule_ack(struct sock *sk)
196 {
197 inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED;
198 }
199
inet_csk_ack_scheduled(const struct sock * sk)200 static inline int inet_csk_ack_scheduled(const struct sock *sk)
201 {
202 return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED;
203 }
204
inet_csk_delack_init(struct sock * sk)205 static inline void inet_csk_delack_init(struct sock *sk)
206 {
207 memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack));
208 }
209
210 void inet_csk_delete_keepalive_timer(struct sock *sk);
211 void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout);
212
inet_csk_clear_xmit_timer(struct sock * sk,const int what)213 static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what)
214 {
215 struct inet_connection_sock *icsk = inet_csk(sk);
216
217 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
218 icsk->icsk_pending = 0;
219 #ifdef INET_CSK_CLEAR_TIMERS
220 sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
221 #endif
222 } else if (what == ICSK_TIME_DACK) {
223 icsk->icsk_ack.blocked = icsk->icsk_ack.pending = 0;
224 #ifdef INET_CSK_CLEAR_TIMERS
225 sk_stop_timer(sk, &icsk->icsk_delack_timer);
226 #endif
227 } else {
228 pr_debug("inet_csk BUG: unknown timer value\n");
229 }
230 }
231
232 /*
233 * Reset the retransmission timer
234 */
inet_csk_reset_xmit_timer(struct sock * sk,const int what,unsigned long when,const unsigned long max_when)235 static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what,
236 unsigned long when,
237 const unsigned long max_when)
238 {
239 struct inet_connection_sock *icsk = inet_csk(sk);
240
241 if (when > max_when) {
242 pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n",
243 sk, what, when, (void *)_THIS_IP_);
244 when = max_when;
245 }
246
247 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0 ||
248 what == ICSK_TIME_EARLY_RETRANS || what == ICSK_TIME_LOSS_PROBE ||
249 what == ICSK_TIME_REO_TIMEOUT) {
250 icsk->icsk_pending = what;
251 icsk->icsk_timeout = jiffies + when;
252 sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout);
253 } else if (what == ICSK_TIME_DACK) {
254 icsk->icsk_ack.pending |= ICSK_ACK_TIMER;
255 icsk->icsk_ack.timeout = jiffies + when;
256 sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout);
257 } else {
258 pr_debug("inet_csk BUG: unknown timer value\n");
259 }
260 }
261
262 static inline unsigned long
inet_csk_rto_backoff(const struct inet_connection_sock * icsk,unsigned long max_when)263 inet_csk_rto_backoff(const struct inet_connection_sock *icsk,
264 unsigned long max_when)
265 {
266 u64 when = (u64)icsk->icsk_rto << icsk->icsk_backoff;
267
268 return (unsigned long)min_t(u64, when, max_when);
269 }
270
271 struct sock *inet_csk_accept(struct sock *sk, int flags, int *err, bool kern);
272
273 int inet_csk_get_port(struct sock *sk, unsigned short snum);
274
275 struct dst_entry *inet_csk_route_req(const struct sock *sk, struct flowi4 *fl4,
276 const struct request_sock *req);
277 struct dst_entry *inet_csk_route_child_sock(const struct sock *sk,
278 struct sock *newsk,
279 const struct request_sock *req);
280
281 struct sock *inet_csk_reqsk_queue_add(struct sock *sk,
282 struct request_sock *req,
283 struct sock *child);
284 void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
285 unsigned long timeout);
286 struct sock *inet_csk_complete_hashdance(struct sock *sk, struct sock *child,
287 struct request_sock *req,
288 bool own_req);
289
inet_csk_reqsk_queue_added(struct sock * sk)290 static inline void inet_csk_reqsk_queue_added(struct sock *sk)
291 {
292 reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue);
293 }
294
inet_csk_reqsk_queue_len(const struct sock * sk)295 static inline int inet_csk_reqsk_queue_len(const struct sock *sk)
296 {
297 return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue);
298 }
299
inet_csk_reqsk_queue_is_full(const struct sock * sk)300 static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk)
301 {
302 return inet_csk_reqsk_queue_len(sk) >= sk->sk_max_ack_backlog;
303 }
304
305 bool inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req);
306 void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req);
307
308 void inet_csk_destroy_sock(struct sock *sk);
309 void inet_csk_prepare_forced_close(struct sock *sk);
310
311 /*
312 * LISTEN is a special case for poll..
313 */
inet_csk_listen_poll(const struct sock * sk)314 static inline __poll_t inet_csk_listen_poll(const struct sock *sk)
315 {
316 return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ?
317 (EPOLLIN | EPOLLRDNORM) : 0;
318 }
319
320 int inet_csk_listen_start(struct sock *sk, int backlog);
321 void inet_csk_listen_stop(struct sock *sk);
322
323 void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr);
324
325 int inet_csk_compat_getsockopt(struct sock *sk, int level, int optname,
326 char __user *optval, int __user *optlen);
327 int inet_csk_compat_setsockopt(struct sock *sk, int level, int optname,
328 char __user *optval, unsigned int optlen);
329
330 /* update the fast reuse flag when adding a socket */
331 void inet_csk_update_fastreuse(struct inet_bind_bucket *tb,
332 struct sock *sk);
333
334 struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu);
335
336 #define TCP_PINGPONG_THRESH 3
337
inet_csk_enter_pingpong_mode(struct sock * sk)338 static inline void inet_csk_enter_pingpong_mode(struct sock *sk)
339 {
340 inet_csk(sk)->icsk_ack.pingpong = TCP_PINGPONG_THRESH;
341 }
342
inet_csk_exit_pingpong_mode(struct sock * sk)343 static inline void inet_csk_exit_pingpong_mode(struct sock *sk)
344 {
345 inet_csk(sk)->icsk_ack.pingpong = 0;
346 }
347
inet_csk_in_pingpong_mode(struct sock * sk)348 static inline bool inet_csk_in_pingpong_mode(struct sock *sk)
349 {
350 return inet_csk(sk)->icsk_ack.pingpong >= TCP_PINGPONG_THRESH;
351 }
352
inet_csk_inc_pingpong_cnt(struct sock * sk)353 static inline void inet_csk_inc_pingpong_cnt(struct sock *sk)
354 {
355 struct inet_connection_sock *icsk = inet_csk(sk);
356
357 if (icsk->icsk_ack.pingpong < U8_MAX)
358 icsk->icsk_ack.pingpong++;
359 }
360 #endif /* _INET_CONNECTION_SOCK_H */
361