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