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 (*)(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 ; |
46 | u16 ; |
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_ca_state: Congestion control state |
70 | * @icsk_retransmits: Number of unrecovered [RTO] timeouts |
71 | * @icsk_pending: Scheduled timer event |
72 | * @icsk_backoff: Backoff |
73 | * @icsk_syn_retries: Number of allowed SYN (or equivalent) retries |
74 | * @icsk_probes_out: unanswered 0 window probes |
75 | * @icsk_ext_hdr_len: Network protocol overhead (IP/IPv6 options) |
76 | * @icsk_ack: Delayed ACK control data |
77 | * @icsk_mtup; MTU probing control data |
78 | * @icsk_probes_tstamp: Probe timestamp (cleared by non-zero window ack) |
79 | * @icsk_user_timeout: TCP_USER_TIMEOUT value |
80 | */ |
81 | struct inet_connection_sock { |
82 | /* inet_sock has to be the first member! */ |
83 | struct inet_sock icsk_inet; |
84 | struct request_sock_queue icsk_accept_queue; |
85 | struct inet_bind_bucket *icsk_bind_hash; |
86 | unsigned long icsk_timeout; |
87 | struct timer_list icsk_retransmit_timer; |
88 | struct timer_list icsk_delack_timer; |
89 | __u32 icsk_rto; |
90 | __u32 icsk_rto_min; |
91 | __u32 icsk_delack_max; |
92 | __u32 icsk_pmtu_cookie; |
93 | const struct tcp_congestion_ops *icsk_ca_ops; |
94 | const struct inet_connection_sock_af_ops *icsk_af_ops; |
95 | const struct tcp_ulp_ops *icsk_ulp_ops; |
96 | void __rcu *icsk_ulp_data; |
97 | void (*icsk_clean_acked)(struct sock *sk, u32 acked_seq); |
98 | unsigned int (*icsk_sync_mss)(struct sock *sk, u32 pmtu); |
99 | __u8 icsk_ca_state:5, |
100 | icsk_ca_initialized:1, |
101 | icsk_ca_setsockopt:1, |
102 | icsk_ca_dst_locked:1; |
103 | __u8 icsk_retransmits; |
104 | __u8 icsk_pending; |
105 | __u8 icsk_backoff; |
106 | __u8 icsk_syn_retries; |
107 | __u8 icsk_probes_out; |
108 | __u16 icsk_ext_hdr_len; |
109 | struct { |
110 | __u8 pending; /* ACK is pending */ |
111 | __u8 quick; /* Scheduled number of quick acks */ |
112 | __u8 pingpong; /* The session is interactive */ |
113 | __u8 retry; /* Number of attempts */ |
114 | __u32 ato; /* Predicted tick of soft clock */ |
115 | unsigned long timeout; /* Currently scheduled timeout */ |
116 | __u32 lrcvtime; /* timestamp of last received data packet */ |
117 | __u16 last_seg_size; /* Size of last incoming segment */ |
118 | __u16 rcv_mss; /* MSS used for delayed ACK decisions */ |
119 | } icsk_ack; |
120 | struct { |
121 | /* Range of MTUs to search */ |
122 | int search_high; |
123 | int search_low; |
124 | |
125 | /* Information on the current probe. */ |
126 | u32 probe_size:31, |
127 | /* Is the MTUP feature enabled for this connection? */ |
128 | enabled:1; |
129 | |
130 | u32 probe_timestamp; |
131 | } icsk_mtup; |
132 | u32 icsk_probes_tstamp; |
133 | u32 icsk_user_timeout; |
134 | |
135 | u64 icsk_ca_priv[104 / sizeof(u64)]; |
136 | #define ICSK_CA_PRIV_SIZE sizeof_field(struct inet_connection_sock, icsk_ca_priv) |
137 | }; |
138 | |
139 | #define ICSK_TIME_RETRANS 1 /* Retransmit timer */ |
140 | #define ICSK_TIME_DACK 2 /* Delayed ack timer */ |
141 | #define ICSK_TIME_PROBE0 3 /* Zero window probe timer */ |
142 | #define ICSK_TIME_LOSS_PROBE 5 /* Tail loss probe timer */ |
143 | #define ICSK_TIME_REO_TIMEOUT 6 /* Reordering timer */ |
144 | |
145 | static inline struct inet_connection_sock *inet_csk(const struct sock *sk) |
146 | { |
147 | return (struct inet_connection_sock *)sk; |
148 | } |
149 | |
150 | static inline void *inet_csk_ca(const struct sock *sk) |
151 | { |
152 | return (void *)inet_csk(sk)->icsk_ca_priv; |
153 | } |
154 | |
155 | struct sock *inet_csk_clone_lock(const struct sock *sk, |
156 | const struct request_sock *req, |
157 | const gfp_t priority); |
158 | |
159 | enum inet_csk_ack_state_t { |
160 | ICSK_ACK_SCHED = 1, |
161 | ICSK_ACK_TIMER = 2, |
162 | ICSK_ACK_PUSHED = 4, |
163 | ICSK_ACK_PUSHED2 = 8, |
164 | ICSK_ACK_NOW = 16 /* Send the next ACK immediately (once) */ |
165 | }; |
166 | |
167 | void inet_csk_init_xmit_timers(struct sock *sk, |
168 | void (*retransmit_handler)(struct timer_list *), |
169 | void (*delack_handler)(struct timer_list *), |
170 | void (*keepalive_handler)(struct timer_list *)); |
171 | void inet_csk_clear_xmit_timers(struct sock *sk); |
172 | |
173 | static inline void inet_csk_schedule_ack(struct sock *sk) |
174 | { |
175 | inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED; |
176 | } |
177 | |
178 | static inline int inet_csk_ack_scheduled(const struct sock *sk) |
179 | { |
180 | return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED; |
181 | } |
182 | |
183 | static inline void inet_csk_delack_init(struct sock *sk) |
184 | { |
185 | memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack)); |
186 | } |
187 | |
188 | void inet_csk_delete_keepalive_timer(struct sock *sk); |
189 | void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout); |
190 | |
191 | static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what) |
192 | { |
193 | struct inet_connection_sock *icsk = inet_csk(sk); |
194 | |
195 | if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) { |
196 | icsk->icsk_pending = 0; |
197 | #ifdef INET_CSK_CLEAR_TIMERS |
198 | sk_stop_timer(sk, &icsk->icsk_retransmit_timer); |
199 | #endif |
200 | } else if (what == ICSK_TIME_DACK) { |
201 | icsk->icsk_ack.pending = 0; |
202 | icsk->icsk_ack.retry = 0; |
203 | #ifdef INET_CSK_CLEAR_TIMERS |
204 | sk_stop_timer(sk, &icsk->icsk_delack_timer); |
205 | #endif |
206 | } else { |
207 | pr_debug("inet_csk BUG: unknown timer value\n" ); |
208 | } |
209 | } |
210 | |
211 | /* |
212 | * Reset the retransmission timer |
213 | */ |
214 | static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what, |
215 | unsigned long when, |
216 | const unsigned long max_when) |
217 | { |
218 | struct inet_connection_sock *icsk = inet_csk(sk); |
219 | |
220 | if (when > max_when) { |
221 | pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n" , |
222 | sk, what, when, (void *)_THIS_IP_); |
223 | when = max_when; |
224 | } |
225 | |
226 | if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0 || |
227 | what == ICSK_TIME_LOSS_PROBE || what == ICSK_TIME_REO_TIMEOUT) { |
228 | icsk->icsk_pending = what; |
229 | icsk->icsk_timeout = jiffies + when; |
230 | sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout); |
231 | } else if (what == ICSK_TIME_DACK) { |
232 | icsk->icsk_ack.pending |= ICSK_ACK_TIMER; |
233 | icsk->icsk_ack.timeout = jiffies + when; |
234 | sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout); |
235 | } else { |
236 | pr_debug("inet_csk BUG: unknown timer value\n" ); |
237 | } |
238 | } |
239 | |
240 | static inline unsigned long |
241 | inet_csk_rto_backoff(const struct inet_connection_sock *icsk, |
242 | unsigned long max_when) |
243 | { |
244 | u64 when = (u64)icsk->icsk_rto << icsk->icsk_backoff; |
245 | |
246 | return (unsigned long)min_t(u64, when, max_when); |
247 | } |
248 | |
249 | struct sock *inet_csk_accept(struct sock *sk, int flags, int *err, bool kern); |
250 | |
251 | int inet_csk_get_port(struct sock *sk, unsigned short snum); |
252 | |
253 | struct dst_entry *inet_csk_route_req(const struct sock *sk, struct flowi4 *fl4, |
254 | const struct request_sock *req); |
255 | struct dst_entry *inet_csk_route_child_sock(const struct sock *sk, |
256 | struct sock *newsk, |
257 | const struct request_sock *req); |
258 | |
259 | struct sock *inet_csk_reqsk_queue_add(struct sock *sk, |
260 | struct request_sock *req, |
261 | struct sock *child); |
262 | void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req, |
263 | unsigned long timeout); |
264 | struct sock *inet_csk_complete_hashdance(struct sock *sk, struct sock *child, |
265 | struct request_sock *req, |
266 | bool own_req); |
267 | |
268 | static inline void inet_csk_reqsk_queue_added(struct sock *sk) |
269 | { |
270 | reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue); |
271 | } |
272 | |
273 | static inline int inet_csk_reqsk_queue_len(const struct sock *sk) |
274 | { |
275 | return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue); |
276 | } |
277 | |
278 | static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk) |
279 | { |
280 | return inet_csk_reqsk_queue_len(sk) >= sk->sk_max_ack_backlog; |
281 | } |
282 | |
283 | bool inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req); |
284 | void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req); |
285 | |
286 | static inline unsigned long |
287 | reqsk_timeout(struct request_sock *req, unsigned long max_timeout) |
288 | { |
289 | u64 timeout = (u64)req->timeout << req->num_timeout; |
290 | |
291 | return (unsigned long)min_t(u64, timeout, max_timeout); |
292 | } |
293 | |
294 | static inline void inet_csk_prepare_for_destroy_sock(struct sock *sk) |
295 | { |
296 | /* The below has to be done to allow calling inet_csk_destroy_sock */ |
297 | sock_set_flag(sk, SOCK_DEAD); |
298 | this_cpu_inc(*sk->sk_prot->orphan_count); |
299 | } |
300 | |
301 | void inet_csk_destroy_sock(struct sock *sk); |
302 | void inet_csk_prepare_forced_close(struct sock *sk); |
303 | |
304 | /* |
305 | * LISTEN is a special case for poll.. |
306 | */ |
307 | static inline __poll_t inet_csk_listen_poll(const struct sock *sk) |
308 | { |
309 | return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ? |
310 | (EPOLLIN | EPOLLRDNORM) : 0; |
311 | } |
312 | |
313 | int inet_csk_listen_start(struct sock *sk); |
314 | void inet_csk_listen_stop(struct sock *sk); |
315 | |
316 | void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr); |
317 | |
318 | /* update the fast reuse flag when adding a socket */ |
319 | void inet_csk_update_fastreuse(struct inet_bind_bucket *tb, |
320 | struct sock *sk); |
321 | |
322 | struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu); |
323 | |
324 | #define TCP_PINGPONG_THRESH 1 |
325 | |
326 | static inline void inet_csk_enter_pingpong_mode(struct sock *sk) |
327 | { |
328 | inet_csk(sk)->icsk_ack.pingpong = TCP_PINGPONG_THRESH; |
329 | } |
330 | |
331 | static inline void inet_csk_exit_pingpong_mode(struct sock *sk) |
332 | { |
333 | inet_csk(sk)->icsk_ack.pingpong = 0; |
334 | } |
335 | |
336 | static inline bool inet_csk_in_pingpong_mode(struct sock *sk) |
337 | { |
338 | return inet_csk(sk)->icsk_ack.pingpong >= TCP_PINGPONG_THRESH; |
339 | } |
340 | |
341 | static inline bool inet_csk_has_ulp(struct sock *sk) |
342 | { |
343 | return inet_sk(sk)->is_icsk && !!inet_csk(sk)->icsk_ulp_ops; |
344 | } |
345 | |
346 | #endif /* _INET_CONNECTION_SOCK_H */ |
347 | |