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 #ifdef CONFIG_TCP_NB_URC
112 __u8 icsk_nb_urc_enabled:1,
113 icsk_nb_urc_reserved:7;
114 __u32 icsk_nb_urc_rto;
115 #endif /* CONFIG_TCP_NB_URC */
116 struct {
117 __u8 pending; /* ACK is pending */
118 __u8 quick; /* Scheduled number of quick acks */
119 __u8 pingpong; /* The session is interactive */
120 __u8 retry; /* Number of attempts */
121 __u32 ato; /* Predicted tick of soft clock */
122 unsigned long timeout; /* Currently scheduled timeout */
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 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 u32 icsk_probes_tstamp;
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
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 };
174
175 void 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 *));
179 void inet_csk_clear_xmit_timers(struct sock *sk);
180
inet_csk_schedule_ack(struct sock * sk)181 static inline void inet_csk_schedule_ack(struct sock *sk)
182 {
183 inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED;
184 }
185
inet_csk_ack_scheduled(const struct sock * sk)186 static inline int inet_csk_ack_scheduled(const struct sock *sk)
187 {
188 return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED;
189 }
190
inet_csk_delack_init(struct sock * sk)191 static 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
196 void inet_csk_delete_keepalive_timer(struct sock *sk);
197 void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout);
198
inet_csk_clear_xmit_timer(struct sock * sk,const int what)199 static 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.pending = 0;
210 icsk->icsk_ack.retry = 0;
211 #ifdef INET_CSK_CLEAR_TIMERS
212 sk_stop_timer(sk, &icsk->icsk_delack_timer);
213 #endif
214 } else {
215 pr_debug("inet_csk BUG: unknown timer value\n");
216 }
217 }
218
219 /*
220 * Reset the retransmission timer
221 */
inet_csk_reset_xmit_timer(struct sock * sk,const int what,unsigned long when,const unsigned long max_when)222 static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what,
223 unsigned long when,
224 const unsigned long max_when)
225 {
226 struct inet_connection_sock *icsk = inet_csk(sk);
227
228 #ifdef CONFIG_TCP_NB_URC
229 if (icsk->icsk_nb_urc_enabled)
230 when = icsk->icsk_nb_urc_rto;
231 #endif /* CONFIG_TCP_NB_URC */
232
233 if (when > max_when) {
234 pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n",
235 sk, what, when, (void *)_THIS_IP_);
236 when = max_when;
237 }
238
239 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0 ||
240 what == ICSK_TIME_EARLY_RETRANS || what == ICSK_TIME_LOSS_PROBE ||
241 what == ICSK_TIME_REO_TIMEOUT) {
242 icsk->icsk_pending = what;
243 icsk->icsk_timeout = jiffies + when;
244 sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout);
245 } else if (what == ICSK_TIME_DACK) {
246 icsk->icsk_ack.pending |= ICSK_ACK_TIMER;
247 icsk->icsk_ack.timeout = jiffies + when;
248 sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout);
249 } else {
250 pr_debug("inet_csk BUG: unknown timer value\n");
251 }
252 }
253
254 static inline unsigned long
inet_csk_rto_backoff(const struct inet_connection_sock * icsk,unsigned long max_when)255 inet_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
263 struct sock *inet_csk_accept(struct sock *sk, int flags, int *err, bool kern);
264
265 int inet_csk_get_port(struct sock *sk, unsigned short snum);
266
267 struct dst_entry *inet_csk_route_req(const struct sock *sk, struct flowi4 *fl4,
268 const struct request_sock *req);
269 struct dst_entry *inet_csk_route_child_sock(const struct sock *sk,
270 struct sock *newsk,
271 const struct request_sock *req);
272
273 struct sock *inet_csk_reqsk_queue_add(struct sock *sk,
274 struct request_sock *req,
275 struct sock *child);
276 void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
277 unsigned long timeout);
278 struct sock *inet_csk_complete_hashdance(struct sock *sk, struct sock *child,
279 struct request_sock *req,
280 bool own_req);
281
inet_csk_reqsk_queue_added(struct sock * sk)282 static inline void inet_csk_reqsk_queue_added(struct sock *sk)
283 {
284 reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue);
285 }
286
inet_csk_reqsk_queue_len(const struct sock * sk)287 static inline int inet_csk_reqsk_queue_len(const struct sock *sk)
288 {
289 return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue);
290 }
291
inet_csk_reqsk_queue_is_full(const struct sock * sk)292 static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk)
293 {
294 return inet_csk_reqsk_queue_len(sk) >= sk->sk_max_ack_backlog;
295 }
296
297 bool inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req);
298 void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req);
299
inet_csk_prepare_for_destroy_sock(struct sock * sk)300 static inline void inet_csk_prepare_for_destroy_sock(struct sock *sk)
301 {
302 /* The below has to be done to allow calling inet_csk_destroy_sock */
303 sock_set_flag(sk, SOCK_DEAD);
304 this_cpu_inc(*sk->sk_prot->orphan_count);
305 }
306
307 void inet_csk_destroy_sock(struct sock *sk);
308 void inet_csk_prepare_forced_close(struct sock *sk);
309
310 /*
311 * LISTEN is a special case for poll..
312 */
inet_csk_listen_poll(const struct sock * sk)313 static inline __poll_t inet_csk_listen_poll(const struct sock *sk)
314 {
315 return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ?
316 (EPOLLIN | EPOLLRDNORM) : 0;
317 }
318
319 int inet_csk_listen_start(struct sock *sk, int backlog);
320 void inet_csk_listen_stop(struct sock *sk);
321
322 void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr);
323
324 /* update the fast reuse flag when adding a socket */
325 void inet_csk_update_fastreuse(struct inet_bind_bucket *tb,
326 struct sock *sk);
327
328 struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu);
329
330 #define TCP_PINGPONG_THRESH 1
331
inet_csk_enter_pingpong_mode(struct sock * sk)332 static inline void inet_csk_enter_pingpong_mode(struct sock *sk)
333 {
334 inet_csk(sk)->icsk_ack.pingpong = TCP_PINGPONG_THRESH;
335 }
336
inet_csk_exit_pingpong_mode(struct sock * sk)337 static inline void inet_csk_exit_pingpong_mode(struct sock *sk)
338 {
339 inet_csk(sk)->icsk_ack.pingpong = 0;
340 }
341
inet_csk_in_pingpong_mode(struct sock * sk)342 static inline bool inet_csk_in_pingpong_mode(struct sock *sk)
343 {
344 return inet_csk(sk)->icsk_ack.pingpong >= TCP_PINGPONG_THRESH;
345 }
346
inet_csk_has_ulp(struct sock * sk)347 static inline bool inet_csk_has_ulp(struct sock *sk)
348 {
349 return inet_sk(sk)->is_icsk && !!inet_csk(sk)->icsk_ulp_ops;
350 }
351
inet_init_csk_locks(struct sock * sk)352 static 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 */
361