Line data Source code
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 (13 * sizeof(u64))
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 :
147 13648 : static inline struct inet_connection_sock *inet_csk(const struct sock *sk)
148 : {
149 11317 : return (struct inet_connection_sock *)sk;
150 : }
151 :
152 941 : static inline void *inet_csk_ca(const struct sock *sk)
153 : {
154 937 : 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 :
175 70 : static inline void inet_csk_schedule_ack(struct sock *sk)
176 : {
177 70 : inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED;
178 0 : }
179 :
180 228 : static inline int inet_csk_ack_scheduled(const struct sock *sk)
181 : {
182 228 : return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED;
183 : }
184 :
185 3 : static inline void inet_csk_delack_init(struct sock *sk)
186 : {
187 3 : 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 :
193 660 : static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what)
194 : {
195 660 : struct inet_connection_sock *icsk = inet_csk(sk);
196 :
197 660 : if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
198 234 : icsk->icsk_pending = 0;
199 : #ifdef INET_CSK_CLEAR_TIMERS
200 : sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
201 : #endif
202 426 : } else if (what == ICSK_TIME_DACK) {
203 426 : icsk->icsk_ack.pending = 0;
204 426 : 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 : }
211 660 : }
212 :
213 : /*
214 : * Reset the retransmission timer
215 : */
216 351 : 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 : {
220 351 : struct inet_connection_sock *icsk = inet_csk(sk);
221 :
222 351 : if (when > max_when) {
223 0 : 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 :
228 351 : if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0 ||
229 0 : what == ICSK_TIME_LOSS_PROBE || what == ICSK_TIME_REO_TIMEOUT) {
230 351 : icsk->icsk_pending = what;
231 351 : icsk->icsk_timeout = jiffies + when;
232 351 : sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout);
233 0 : } else if (what == ICSK_TIME_DACK) {
234 0 : icsk->icsk_ack.pending |= ICSK_ACK_TIMER;
235 0 : icsk->icsk_ack.timeout = jiffies + when;
236 0 : 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 0 : }
241 :
242 : static inline unsigned long
243 0 : inet_csk_rto_backoff(const struct inet_connection_sock *icsk,
244 : unsigned long max_when)
245 : {
246 0 : u64 when = (u64)icsk->icsk_rto << icsk->icsk_backoff;
247 :
248 0 : 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 :
270 4 : static inline void inet_csk_reqsk_queue_added(struct sock *sk)
271 : {
272 4 : reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue);
273 : }
274 :
275 4 : static inline int inet_csk_reqsk_queue_len(const struct sock *sk)
276 : {
277 0 : return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue);
278 : }
279 :
280 4 : static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk)
281 : {
282 4 : return inet_csk_reqsk_queue_len(sk) >= sk->sk_max_ack_backlog;
283 : }
284 :
285 : void 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 :
288 0 : 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 0 : sock_set_flag(sk, SOCK_DEAD);
292 0 : percpu_counter_inc(sk->sk_prot->orphan_count);
293 0 : }
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 : */
301 29 : static inline __poll_t inet_csk_listen_poll(const struct sock *sk)
302 : {
303 29 : return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ?
304 29 : (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 :
320 3 : static inline void inet_csk_enter_pingpong_mode(struct sock *sk)
321 : {
322 3 : inet_csk(sk)->icsk_ack.pingpong = TCP_PINGPONG_THRESH;
323 3 : }
324 :
325 2 : static inline void inet_csk_exit_pingpong_mode(struct sock *sk)
326 : {
327 2 : inet_csk(sk)->icsk_ack.pingpong = 0;
328 : }
329 :
330 60 : static inline bool inet_csk_in_pingpong_mode(struct sock *sk)
331 : {
332 60 : return inet_csk(sk)->icsk_ack.pingpong >= TCP_PINGPONG_THRESH;
333 : }
334 :
335 15 : static inline void inet_csk_inc_pingpong_cnt(struct sock *sk)
336 : {
337 15 : struct inet_connection_sock *icsk = inet_csk(sk);
338 :
339 15 : if (icsk->icsk_ack.pingpong < U8_MAX)
340 15 : icsk->icsk_ack.pingpong++;
341 : }
342 :
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 */
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