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 #include <linux/android_kabi.h>
21
22 #include <net/inet_sock.h>
23 #include <net/request_sock.h>
24
25 /* Cancel timers, when they are not required. */
26 #undef INET_CSK_CLEAR_TIMERS
27
28 struct inet_bind_bucket;
29 struct inet_bind2_bucket;
30 struct tcp_congestion_ops;
31
32 /*
33 * Pointers to address related TCP functions
34 * (i.e. things that depend on the address family)
35 */
36 struct inet_connection_sock_af_ops {
37 int (*queue_xmit)(struct sock *sk, struct sk_buff *skb, struct flowi *fl);
38 void (*send_check)(struct sock *sk, struct sk_buff *skb);
39 int (*rebuild_header)(struct sock *sk);
40 void (*sk_rx_dst_set)(struct sock *sk, const struct sk_buff *skb);
41 int (*conn_request)(struct sock *sk, struct sk_buff *skb);
42 struct sock *(*syn_recv_sock)(const struct sock *sk, struct sk_buff *skb,
43 struct request_sock *req,
44 struct dst_entry *dst,
45 struct request_sock *req_unhash,
46 bool *own_req);
47 u16 net_header_len;
48 u16 net_frag_header_len;
49 u16 sockaddr_len;
50 int (*setsockopt)(struct sock *sk, int level, int optname,
51 sockptr_t optval, unsigned int optlen);
52 int (*getsockopt)(struct sock *sk, int level, int optname,
53 char __user *optval, int __user *optlen);
54 void (*addr2sockaddr)(struct sock *sk, struct sockaddr *);
55 void (*mtu_reduced)(struct sock *sk);
56
57 ANDROID_KABI_RESERVE(1);
58 };
59
60 /** inet_connection_sock - INET connection oriented sock
61 *
62 * @icsk_accept_queue: FIFO of established children
63 * @icsk_bind_hash: Bind node
64 * @icsk_bind2_hash: Bind node in the bhash2 table
65 * @icsk_timeout: Timeout
66 * @icsk_retransmit_timer: Resend (no ack)
67 * @icsk_rto: Retransmit timeout
68 * @icsk_pmtu_cookie Last pmtu seen by socket
69 * @icsk_ca_ops Pluggable congestion control hook
70 * @icsk_af_ops Operations which are AF_INET{4,6} specific
71 * @icsk_ulp_ops Pluggable ULP control hook
72 * @icsk_ulp_data ULP private data
73 * @icsk_clean_acked Clean acked data hook
74 * @icsk_ca_state: Congestion control state
75 * @icsk_retransmits: Number of unrecovered [RTO] timeouts
76 * @icsk_pending: Scheduled timer event
77 * @icsk_backoff: Backoff
78 * @icsk_syn_retries: Number of allowed SYN (or equivalent) retries
79 * @icsk_probes_out: unanswered 0 window probes
80 * @icsk_ext_hdr_len: Network protocol overhead (IP/IPv6 options)
81 * @icsk_ack: Delayed ACK control data
82 * @icsk_mtup; MTU probing control data
83 * @icsk_probes_tstamp: Probe timestamp (cleared by non-zero window ack)
84 * @icsk_user_timeout: TCP_USER_TIMEOUT value
85 */
86 struct inet_connection_sock {
87 /* inet_sock has to be the first member! */
88 struct inet_sock icsk_inet;
89 struct request_sock_queue icsk_accept_queue;
90 struct inet_bind_bucket *icsk_bind_hash;
91 struct inet_bind2_bucket *icsk_bind2_hash;
92 unsigned long icsk_timeout;
93 struct timer_list icsk_retransmit_timer;
94 struct timer_list icsk_delack_timer;
95 __u32 icsk_rto;
96 __u32 icsk_rto_min;
97 __u32 icsk_delack_max;
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 unsigned int (*icsk_sync_mss)(struct sock *sk, u32 pmtu);
105 __u8 icsk_ca_state:5,
106 icsk_ca_initialized:1,
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 retry; /* Number of attempts */
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 struct {
127 /* Range of MTUs to search */
128 int search_high;
129 int search_low;
130
131 /* Information on the current probe. */
132 u32 probe_size:31,
133 /* Is the MTUP feature enabled for this connection? */
134 enabled:1;
135
136 u32 probe_timestamp;
137 } icsk_mtup;
138 u32 icsk_probes_tstamp;
139 u32 icsk_user_timeout;
140
141 ANDROID_KABI_RESERVE(1);
142
143 u64 icsk_ca_priv[104 / sizeof(u64)];
144 #define ICSK_CA_PRIV_SIZE sizeof_field(struct inet_connection_sock, icsk_ca_priv)
145 };
146
147 #define ICSK_TIME_RETRANS 1 /* Retransmit timer */
148 #define ICSK_TIME_DACK 2 /* Delayed ack timer */
149 #define ICSK_TIME_PROBE0 3 /* Zero window probe timer */
150 #define ICSK_TIME_LOSS_PROBE 5 /* Tail loss probe timer */
151 #define ICSK_TIME_REO_TIMEOUT 6 /* Reordering timer */
152
inet_csk(const struct sock * sk)153 static inline struct inet_connection_sock *inet_csk(const struct sock *sk)
154 {
155 return (struct inet_connection_sock *)sk;
156 }
157
inet_csk_ca(const struct sock * sk)158 static inline void *inet_csk_ca(const struct sock *sk)
159 {
160 return (void *)inet_csk(sk)->icsk_ca_priv;
161 }
162
163 struct sock *inet_csk_clone_lock(const struct sock *sk,
164 const struct request_sock *req,
165 const gfp_t priority);
166
167 enum 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 ICSK_ACK_NOMEM = 32,
174 };
175
176 void inet_csk_init_xmit_timers(struct sock *sk,
177 void (*retransmit_handler)(struct timer_list *),
178 void (*delack_handler)(struct timer_list *),
179 void (*keepalive_handler)(struct timer_list *));
180 void inet_csk_clear_xmit_timers(struct sock *sk);
181 void inet_csk_clear_xmit_timers_sync(struct sock *sk);
182
inet_csk_schedule_ack(struct sock * sk)183 static inline void inet_csk_schedule_ack(struct sock *sk)
184 {
185 inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED;
186 }
187
inet_csk_ack_scheduled(const struct sock * sk)188 static inline int inet_csk_ack_scheduled(const struct sock *sk)
189 {
190 return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED;
191 }
192
inet_csk_delack_init(struct sock * sk)193 static inline void inet_csk_delack_init(struct sock *sk)
194 {
195 memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack));
196 }
197
198 void inet_csk_delete_keepalive_timer(struct sock *sk);
199 void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout);
200
inet_csk_clear_xmit_timer(struct sock * sk,const int what)201 static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what)
202 {
203 struct inet_connection_sock *icsk = inet_csk(sk);
204
205 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
206 icsk->icsk_pending = 0;
207 #ifdef INET_CSK_CLEAR_TIMERS
208 sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
209 #endif
210 } else if (what == ICSK_TIME_DACK) {
211 icsk->icsk_ack.pending = 0;
212 icsk->icsk_ack.retry = 0;
213 #ifdef INET_CSK_CLEAR_TIMERS
214 sk_stop_timer(sk, &icsk->icsk_delack_timer);
215 #endif
216 } else {
217 pr_debug("inet_csk BUG: unknown timer value\n");
218 }
219 }
220
221 /*
222 * Reset the retransmission timer
223 */
inet_csk_reset_xmit_timer(struct sock * sk,const int what,unsigned long when,const unsigned long max_when)224 static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what,
225 unsigned long when,
226 const unsigned long max_when)
227 {
228 struct inet_connection_sock *icsk = inet_csk(sk);
229
230 if (when > max_when) {
231 pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n",
232 sk, what, when, (void *)_THIS_IP_);
233 when = max_when;
234 }
235
236 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0 ||
237 what == ICSK_TIME_LOSS_PROBE || what == ICSK_TIME_REO_TIMEOUT) {
238 icsk->icsk_pending = what;
239 icsk->icsk_timeout = jiffies + when;
240 sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout);
241 } else if (what == ICSK_TIME_DACK) {
242 icsk->icsk_ack.pending |= ICSK_ACK_TIMER;
243 icsk->icsk_ack.timeout = jiffies + when;
244 sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout);
245 } else {
246 pr_debug("inet_csk BUG: unknown timer value\n");
247 }
248 }
249
250 static inline unsigned long
inet_csk_rto_backoff(const struct inet_connection_sock * icsk,unsigned long max_when)251 inet_csk_rto_backoff(const struct inet_connection_sock *icsk,
252 unsigned long max_when)
253 {
254 u64 when = (u64)icsk->icsk_rto << icsk->icsk_backoff;
255
256 return (unsigned long)min_t(u64, when, max_when);
257 }
258
259 struct sock *inet_csk_accept(struct sock *sk, int flags, int *err, bool kern);
260
261 int inet_csk_get_port(struct sock *sk, unsigned short snum);
262
263 struct dst_entry *inet_csk_route_req(const struct sock *sk, struct flowi4 *fl4,
264 const struct request_sock *req);
265 struct dst_entry *inet_csk_route_child_sock(const struct sock *sk,
266 struct sock *newsk,
267 const struct request_sock *req);
268
269 struct sock *inet_csk_reqsk_queue_add(struct sock *sk,
270 struct request_sock *req,
271 struct sock *child);
272 bool inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
273 unsigned long timeout);
274 struct sock *inet_csk_complete_hashdance(struct sock *sk, struct sock *child,
275 struct request_sock *req,
276 bool own_req);
277
inet_csk_reqsk_queue_added(struct sock * sk)278 static inline void inet_csk_reqsk_queue_added(struct sock *sk)
279 {
280 reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue);
281 }
282
inet_csk_reqsk_queue_len(const struct sock * sk)283 static inline int inet_csk_reqsk_queue_len(const struct sock *sk)
284 {
285 return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue);
286 }
287
inet_csk_reqsk_queue_is_full(const struct sock * sk)288 static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk)
289 {
290 return inet_csk_reqsk_queue_len(sk) >= sk->sk_max_ack_backlog;
291 }
292
293 bool inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req);
294 void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req);
295
296 static inline unsigned long
reqsk_timeout(struct request_sock * req,unsigned long max_timeout)297 reqsk_timeout(struct request_sock *req, unsigned long max_timeout)
298 {
299 u64 timeout = (u64)req->timeout << req->num_timeout;
300
301 return (unsigned long)min_t(u64, timeout, max_timeout);
302 }
303
inet_csk_prepare_for_destroy_sock(struct sock * sk)304 static inline void inet_csk_prepare_for_destroy_sock(struct sock *sk)
305 {
306 /* The below has to be done to allow calling inet_csk_destroy_sock */
307 sock_set_flag(sk, SOCK_DEAD);
308 this_cpu_inc(*sk->sk_prot->orphan_count);
309 }
310
311 void inet_csk_destroy_sock(struct sock *sk);
312 void inet_csk_prepare_forced_close(struct sock *sk);
313
314 /*
315 * LISTEN is a special case for poll..
316 */
inet_csk_listen_poll(const struct sock * sk)317 static inline __poll_t inet_csk_listen_poll(const struct sock *sk)
318 {
319 return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ?
320 (EPOLLIN | EPOLLRDNORM) : 0;
321 }
322
323 int inet_csk_listen_start(struct sock *sk);
324 void inet_csk_listen_stop(struct sock *sk);
325
326 void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr);
327
328 /* update the fast reuse flag when adding a socket */
329 void inet_csk_update_fastreuse(struct inet_bind_bucket *tb,
330 struct sock *sk);
331
332 struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu);
333
334 #define TCP_PINGPONG_THRESH 1
335
inet_csk_enter_pingpong_mode(struct sock * sk)336 static inline void inet_csk_enter_pingpong_mode(struct sock *sk)
337 {
338 inet_csk(sk)->icsk_ack.pingpong = TCP_PINGPONG_THRESH;
339 }
340
inet_csk_exit_pingpong_mode(struct sock * sk)341 static inline void inet_csk_exit_pingpong_mode(struct sock *sk)
342 {
343 inet_csk(sk)->icsk_ack.pingpong = 0;
344 }
345
inet_csk_in_pingpong_mode(struct sock * sk)346 static inline bool inet_csk_in_pingpong_mode(struct sock *sk)
347 {
348 return inet_csk(sk)->icsk_ack.pingpong >= TCP_PINGPONG_THRESH;
349 }
350
inet_csk_has_ulp(const struct sock * sk)351 static inline bool inet_csk_has_ulp(const struct sock *sk)
352 {
353 return inet_test_bit(IS_ICSK, sk) && !!inet_csk(sk)->icsk_ulp_ops;
354 }
355
inet_init_csk_locks(struct sock * sk)356 static inline void inet_init_csk_locks(struct sock *sk)
357 {
358 struct inet_connection_sock *icsk = inet_csk(sk);
359
360 spin_lock_init(&icsk->icsk_accept_queue.rskq_lock);
361 spin_lock_init(&icsk->icsk_accept_queue.fastopenq.lock);
362 }
363
364 #endif /* _INET_CONNECTION_SOCK_H */
365