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 tcp_congestion_ops;
30
31 /*
32 * Pointers to address related TCP functions
33 * (i.e. things that depend on the address family)
34 */
35 struct inet_connection_sock_af_ops {
36 int (*queue_xmit)(struct sock *sk, struct sk_buff *skb, struct flowi *fl);
37 void (*send_check)(struct sock *sk, struct sk_buff *skb);
38 int (*rebuild_header)(struct sock *sk);
39 void (*sk_rx_dst_set)(struct sock *sk, const struct sk_buff *skb);
40 int (*conn_request)(struct sock *sk, struct sk_buff *skb);
41 struct sock *(*syn_recv_sock)(const struct sock *sk, struct sk_buff *skb,
42 struct request_sock *req,
43 struct dst_entry *dst,
44 struct request_sock *req_unhash,
45 bool *own_req);
46 u16 net_header_len;
47 u16 net_frag_header_len;
48 u16 sockaddr_len;
49 int (*setsockopt)(struct sock *sk, int level, int optname,
50 sockptr_t optval, unsigned int optlen);
51 int (*getsockopt)(struct sock *sk, int level, int optname,
52 char __user *optval, int __user *optlen);
53 void (*addr2sockaddr)(struct sock *sk, struct sockaddr *);
54 void (*mtu_reduced)(struct sock *sk);
55
56 ANDROID_KABI_RESERVE(1);
57 };
58
59 /** inet_connection_sock - INET connection oriented sock
60 *
61 * @icsk_accept_queue: FIFO of established children
62 * @icsk_bind_hash: Bind node
63 * @icsk_timeout: Timeout
64 * @icsk_retransmit_timer: Resend (no ack)
65 * @icsk_rto: Retransmit timeout
66 * @icsk_pmtu_cookie Last pmtu seen by socket
67 * @icsk_ca_ops Pluggable congestion control hook
68 * @icsk_af_ops Operations which are AF_INET{4,6} specific
69 * @icsk_ulp_ops Pluggable ULP control hook
70 * @icsk_ulp_data ULP private data
71 * @icsk_clean_acked Clean acked data hook
72 * @icsk_listen_portaddr_node hash to the portaddr listener hashtable
73 * @icsk_ca_state: Congestion control state
74 * @icsk_retransmits: Number of unrecovered [RTO] timeouts
75 * @icsk_pending: Scheduled timer event
76 * @icsk_backoff: Backoff
77 * @icsk_syn_retries: Number of allowed SYN (or equivalent) retries
78 * @icsk_probes_out: unanswered 0 window probes
79 * @icsk_ext_hdr_len: Network protocol overhead (IP/IPv6 options)
80 * @icsk_ack: Delayed ACK control data
81 * @icsk_mtup; MTU probing control data
82 * @icsk_probes_tstamp: Probe timestamp (cleared by non-zero window ack)
83 * @icsk_user_timeout: TCP_USER_TIMEOUT value
84 */
85 struct inet_connection_sock {
86 /* inet_sock has to be the first member! */
87 struct inet_sock icsk_inet;
88 struct request_sock_queue icsk_accept_queue;
89 struct inet_bind_bucket *icsk_bind_hash;
90 unsigned long icsk_timeout;
91 struct timer_list icsk_retransmit_timer;
92 struct timer_list icsk_delack_timer;
93 __u32 icsk_rto;
94 __u32 icsk_rto_min;
95 __u32 icsk_delack_max;
96 __u32 icsk_pmtu_cookie;
97 const struct tcp_congestion_ops *icsk_ca_ops;
98 const struct inet_connection_sock_af_ops *icsk_af_ops;
99 const struct tcp_ulp_ops *icsk_ulp_ops;
100 void __rcu *icsk_ulp_data;
101 void (*icsk_clean_acked)(struct sock *sk, u32 acked_seq);
102 struct hlist_node icsk_listen_portaddr_node;
103 unsigned int (*icsk_sync_mss)(struct sock *sk, u32 pmtu);
104 __u8 icsk_ca_state:5,
105 icsk_ca_initialized:1,
106 icsk_ca_setsockopt:1,
107 icsk_ca_dst_locked:1;
108 __u8 icsk_retransmits;
109 __u8 icsk_pending;
110 __u8 icsk_backoff;
111 __u8 icsk_syn_retries;
112 __u8 icsk_probes_out;
113 __u16 icsk_ext_hdr_len;
114 struct {
115 __u8 pending; /* ACK is pending */
116 __u8 quick; /* Scheduled number of quick acks */
117 __u8 pingpong; /* The session is interactive */
118 __u8 retry; /* Number of attempts */
119 __u32 ato; /* Predicted tick of soft clock */
120 unsigned long timeout; /* Currently scheduled timeout */
121 __u32 lrcvtime; /* timestamp of last received data packet */
122 __u16 last_seg_size; /* Size of last incoming segment */
123 __u16 rcv_mss; /* MSS used for delayed ACK decisions */
124 } icsk_ack;
125 struct {
126 /* Range of MTUs to search */
127 int search_high;
128 int search_low;
129
130 /* Information on the current probe. */
131 u32 probe_size:31,
132 /* Is the MTUP feature enabled for this connection? */
133 enabled:1;
134
135 u32 probe_timestamp;
136 } icsk_mtup;
137 u32 icsk_probes_tstamp;
138 u32 icsk_user_timeout;
139
140 ANDROID_KABI_RESERVE(1);
141
142 u64 icsk_ca_priv[104 / sizeof(u64)];
143 #define ICSK_CA_PRIV_SIZE sizeof_field(struct inet_connection_sock, icsk_ca_priv)
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_LOSS_PROBE 5 /* Tail loss probe timer */
150 #define ICSK_TIME_REO_TIMEOUT 6 /* Reordering timer */
151
inet_csk(const struct sock * sk)152 static inline struct inet_connection_sock *inet_csk(const struct sock *sk)
153 {
154 return (struct inet_connection_sock *)sk;
155 }
156
inet_csk_ca(const struct sock * sk)157 static inline void *inet_csk_ca(const struct sock *sk)
158 {
159 return (void *)inet_csk(sk)->icsk_ca_priv;
160 }
161
162 struct sock *inet_csk_clone_lock(const struct sock *sk,
163 const struct request_sock *req,
164 const gfp_t priority);
165
166 enum inet_csk_ack_state_t {
167 ICSK_ACK_SCHED = 1,
168 ICSK_ACK_TIMER = 2,
169 ICSK_ACK_PUSHED = 4,
170 ICSK_ACK_PUSHED2 = 8,
171 ICSK_ACK_NOW = 16 /* Send the next ACK immediately (once) */
172 };
173
174 void inet_csk_init_xmit_timers(struct sock *sk,
175 void (*retransmit_handler)(struct timer_list *),
176 void (*delack_handler)(struct timer_list *),
177 void (*keepalive_handler)(struct timer_list *));
178 void inet_csk_clear_xmit_timers(struct sock *sk);
179
inet_csk_schedule_ack(struct sock * sk)180 static inline void inet_csk_schedule_ack(struct sock *sk)
181 {
182 inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_SCHED;
183 }
184
inet_csk_ack_scheduled(const struct sock * sk)185 static inline int inet_csk_ack_scheduled(const struct sock *sk)
186 {
187 return inet_csk(sk)->icsk_ack.pending & ICSK_ACK_SCHED;
188 }
189
inet_csk_delack_init(struct sock * sk)190 static inline void inet_csk_delack_init(struct sock *sk)
191 {
192 memset(&inet_csk(sk)->icsk_ack, 0, sizeof(inet_csk(sk)->icsk_ack));
193 }
194
195 void inet_csk_delete_keepalive_timer(struct sock *sk);
196 void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long timeout);
197
inet_csk_clear_xmit_timer(struct sock * sk,const int what)198 static inline void inet_csk_clear_xmit_timer(struct sock *sk, const int what)
199 {
200 struct inet_connection_sock *icsk = inet_csk(sk);
201
202 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0) {
203 icsk->icsk_pending = 0;
204 #ifdef INET_CSK_CLEAR_TIMERS
205 sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
206 #endif
207 } else if (what == ICSK_TIME_DACK) {
208 icsk->icsk_ack.pending = 0;
209 icsk->icsk_ack.retry = 0;
210 #ifdef INET_CSK_CLEAR_TIMERS
211 sk_stop_timer(sk, &icsk->icsk_delack_timer);
212 #endif
213 } else {
214 pr_debug("inet_csk BUG: unknown timer value\n");
215 }
216 }
217
218 /*
219 * Reset the retransmission timer
220 */
inet_csk_reset_xmit_timer(struct sock * sk,const int what,unsigned long when,const unsigned long max_when)221 static inline void inet_csk_reset_xmit_timer(struct sock *sk, const int what,
222 unsigned long when,
223 const unsigned long max_when)
224 {
225 struct inet_connection_sock *icsk = inet_csk(sk);
226
227 if (when > max_when) {
228 pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n",
229 sk, what, when, (void *)_THIS_IP_);
230 when = max_when;
231 }
232
233 if (what == ICSK_TIME_RETRANS || what == ICSK_TIME_PROBE0 ||
234 what == ICSK_TIME_LOSS_PROBE || what == ICSK_TIME_REO_TIMEOUT) {
235 icsk->icsk_pending = what;
236 icsk->icsk_timeout = jiffies + when;
237 sk_reset_timer(sk, &icsk->icsk_retransmit_timer, icsk->icsk_timeout);
238 } else if (what == ICSK_TIME_DACK) {
239 icsk->icsk_ack.pending |= ICSK_ACK_TIMER;
240 icsk->icsk_ack.timeout = jiffies + when;
241 sk_reset_timer(sk, &icsk->icsk_delack_timer, icsk->icsk_ack.timeout);
242 } else {
243 pr_debug("inet_csk BUG: unknown timer value\n");
244 }
245 }
246
247 static inline unsigned long
inet_csk_rto_backoff(const struct inet_connection_sock * icsk,unsigned long max_when)248 inet_csk_rto_backoff(const struct inet_connection_sock *icsk,
249 unsigned long max_when)
250 {
251 u64 when = (u64)icsk->icsk_rto << icsk->icsk_backoff;
252
253 return (unsigned long)min_t(u64, when, max_when);
254 }
255
256 struct sock *inet_csk_accept(struct sock *sk, int flags, int *err, bool kern);
257
258 int inet_csk_get_port(struct sock *sk, unsigned short snum);
259
260 struct dst_entry *inet_csk_route_req(const struct sock *sk, struct flowi4 *fl4,
261 const struct request_sock *req);
262 struct dst_entry *inet_csk_route_child_sock(const struct sock *sk,
263 struct sock *newsk,
264 const struct request_sock *req);
265
266 struct sock *inet_csk_reqsk_queue_add(struct sock *sk,
267 struct request_sock *req,
268 struct sock *child);
269 void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req,
270 unsigned long timeout);
271 struct sock *inet_csk_complete_hashdance(struct sock *sk, struct sock *child,
272 struct request_sock *req,
273 bool own_req);
274
inet_csk_reqsk_queue_added(struct sock * sk)275 static inline void inet_csk_reqsk_queue_added(struct sock *sk)
276 {
277 reqsk_queue_added(&inet_csk(sk)->icsk_accept_queue);
278 }
279
inet_csk_reqsk_queue_len(const struct sock * sk)280 static inline int inet_csk_reqsk_queue_len(const struct sock *sk)
281 {
282 return reqsk_queue_len(&inet_csk(sk)->icsk_accept_queue);
283 }
284
inet_csk_reqsk_queue_is_full(const struct sock * sk)285 static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk)
286 {
287 return inet_csk_reqsk_queue_len(sk) >= sk->sk_max_ack_backlog;
288 }
289
290 bool inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req);
291 void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req);
292
inet_csk_prepare_for_destroy_sock(struct sock * sk)293 static inline void inet_csk_prepare_for_destroy_sock(struct sock *sk)
294 {
295 /* The below has to be done to allow calling inet_csk_destroy_sock */
296 sock_set_flag(sk, SOCK_DEAD);
297 this_cpu_inc(*sk->sk_prot->orphan_count);
298 }
299
300 void inet_csk_destroy_sock(struct sock *sk);
301 void inet_csk_prepare_forced_close(struct sock *sk);
302
303 /*
304 * LISTEN is a special case for poll..
305 */
inet_csk_listen_poll(const struct sock * sk)306 static inline __poll_t inet_csk_listen_poll(const struct sock *sk)
307 {
308 return !reqsk_queue_empty(&inet_csk(sk)->icsk_accept_queue) ?
309 (EPOLLIN | EPOLLRDNORM) : 0;
310 }
311
312 int inet_csk_listen_start(struct sock *sk, int backlog);
313 void inet_csk_listen_stop(struct sock *sk);
314
315 void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr);
316
317 /* update the fast reuse flag when adding a socket */
318 void inet_csk_update_fastreuse(struct inet_bind_bucket *tb,
319 struct sock *sk);
320
321 struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu);
322
323 #define TCP_PINGPONG_THRESH 1
324
inet_csk_enter_pingpong_mode(struct sock * sk)325 static inline void inet_csk_enter_pingpong_mode(struct sock *sk)
326 {
327 inet_csk(sk)->icsk_ack.pingpong = TCP_PINGPONG_THRESH;
328 }
329
inet_csk_exit_pingpong_mode(struct sock * sk)330 static inline void inet_csk_exit_pingpong_mode(struct sock *sk)
331 {
332 inet_csk(sk)->icsk_ack.pingpong = 0;
333 }
334
inet_csk_in_pingpong_mode(struct sock * sk)335 static inline bool inet_csk_in_pingpong_mode(struct sock *sk)
336 {
337 return inet_csk(sk)->icsk_ack.pingpong >= TCP_PINGPONG_THRESH;
338 }
339
inet_csk_has_ulp(struct sock * sk)340 static inline bool inet_csk_has_ulp(struct sock *sk)
341 {
342 return inet_sk(sk)->is_icsk && !!inet_csk(sk)->icsk_ulp_ops;
343 }
344
inet_init_csk_locks(struct sock * sk)345 static inline void inet_init_csk_locks(struct sock *sk)
346 {
347 struct inet_connection_sock *icsk = inet_csk(sk);
348
349 spin_lock_init(&icsk->icsk_accept_queue.rskq_lock);
350 spin_lock_init(&icsk->icsk_accept_queue.fastopenq.lock);
351 }
352
353 #endif /* _INET_CONNECTION_SOCK_H */
354