1 /* SPDX-License-Identifier: GPL-2.0-or-later */
3 * NET Generic infrastructure for INET connection oriented protocols.
5 * Definitions for inet_connection_sock
7 * Authors: Many people, see the TCP sources
9 * From code originally in TCP
11 #ifndef _INET_CONNECTION_SOCK_H
12 #define _INET_CONNECTION_SOCK_H
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>
21 #include <net/inet_sock.h>
22 #include <net/request_sock.h>
24 /* Cancel timers, when they are not required. */
25 #undef INET_CSK_CLEAR_TIMERS
27 struct inet_bind_bucket
;
28 struct tcp_congestion_ops
;
31 * Pointers to address related TCP functions
32 * (i.e. things that depend on the address family)
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
,
46 u16 net_frag_header_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
);
56 /** inet_connection_sock - INET connection oriented sock
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
80 struct inet_connection_sock
{
81 /* inet_sock has to be the first member! */
82 struct inet_sock icsk_inet
;
83 struct request_sock_queue icsk_accept_queue
;
84 struct inet_bind_bucket
*icsk_bind_hash
;
85 unsigned long icsk_timeout
;
86 struct timer_list icsk_retransmit_timer
;
87 struct timer_list icsk_delack_timer
;
90 __u32 icsk_delack_max
;
91 __u32 icsk_pmtu_cookie
;
92 const struct tcp_congestion_ops
*icsk_ca_ops
;
93 const struct inet_connection_sock_af_ops
*icsk_af_ops
;
94 const struct tcp_ulp_ops
*icsk_ulp_ops
;
95 void __rcu
*icsk_ulp_data
;
96 void (*icsk_clean_acked
)(struct sock
*sk
, u32 acked_seq
);
97 struct hlist_node icsk_listen_portaddr_node
;
98 unsigned int (*icsk_sync_mss
)(struct sock
*sk
, u32 pmtu
);
100 icsk_ca_initialized
:1,
101 icsk_ca_setsockopt
:1,
102 icsk_ca_dst_locked
:1;
103 __u8 icsk_retransmits
;
106 __u8 icsk_syn_retries
;
107 __u8 icsk_probes_out
;
108 __u16 icsk_ext_hdr_len
;
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 */
123 /* Range of MTUs to search */
127 /* Information on the current probe. */
132 u32 icsk_user_timeout
;
134 u64 icsk_ca_priv
[104 / sizeof(u64
)];
135 #define ICSK_CA_PRIV_SIZE (13 * sizeof(u64))
138 #define ICSK_TIME_RETRANS 1 /* Retransmit timer */
139 #define ICSK_TIME_DACK 2 /* Delayed ack timer */
140 #define ICSK_TIME_PROBE0 3 /* Zero window probe timer */
141 #define ICSK_TIME_EARLY_RETRANS 4 /* Early retransmit timer */
142 #define ICSK_TIME_LOSS_PROBE 5 /* Tail loss probe timer */
143 #define ICSK_TIME_REO_TIMEOUT 6 /* Reordering timer */
145 static inline struct inet_connection_sock
*inet_csk(const struct sock
*sk
)
147 return (struct inet_connection_sock
*)sk
;
150 static inline void *inet_csk_ca(const struct sock
*sk
)
152 return (void *)inet_csk(sk
)->icsk_ca_priv
;
155 struct sock
*inet_csk_clone_lock(const struct sock
*sk
,
156 const struct request_sock
*req
,
157 const gfp_t priority
);
159 enum inet_csk_ack_state_t
{
163 ICSK_ACK_PUSHED2
= 8,
164 ICSK_ACK_NOW
= 16 /* Send the next ACK immediately (once) */
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
);
173 static inline void inet_csk_schedule_ack(struct sock
*sk
)
175 inet_csk(sk
)->icsk_ack
.pending
|= ICSK_ACK_SCHED
;
178 static inline int inet_csk_ack_scheduled(const struct sock
*sk
)
180 return inet_csk(sk
)->icsk_ack
.pending
& ICSK_ACK_SCHED
;
183 static inline void inet_csk_delack_init(struct sock
*sk
)
185 memset(&inet_csk(sk
)->icsk_ack
, 0, sizeof(inet_csk(sk
)->icsk_ack
));
188 void inet_csk_delete_keepalive_timer(struct sock
*sk
);
189 void inet_csk_reset_keepalive_timer(struct sock
*sk
, unsigned long timeout
);
191 static inline void inet_csk_clear_xmit_timer(struct sock
*sk
, const int what
)
193 struct inet_connection_sock
*icsk
= inet_csk(sk
);
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
);
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
);
207 pr_debug("inet_csk BUG: unknown timer value\n");
212 * Reset the retransmission timer
214 static inline void inet_csk_reset_xmit_timer(struct sock
*sk
, const int what
,
216 const unsigned long max_when
)
218 struct inet_connection_sock
*icsk
= inet_csk(sk
);
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_
);
226 if (what
== ICSK_TIME_RETRANS
|| what
== ICSK_TIME_PROBE0
||
227 what
== ICSK_TIME_EARLY_RETRANS
|| what
== ICSK_TIME_LOSS_PROBE
||
228 what
== ICSK_TIME_REO_TIMEOUT
) {
229 icsk
->icsk_pending
= what
;
230 icsk
->icsk_timeout
= jiffies
+ when
;
231 sk_reset_timer(sk
, &icsk
->icsk_retransmit_timer
, icsk
->icsk_timeout
);
232 } else if (what
== ICSK_TIME_DACK
) {
233 icsk
->icsk_ack
.pending
|= ICSK_ACK_TIMER
;
234 icsk
->icsk_ack
.timeout
= jiffies
+ when
;
235 sk_reset_timer(sk
, &icsk
->icsk_delack_timer
, icsk
->icsk_ack
.timeout
);
237 pr_debug("inet_csk BUG: unknown timer value\n");
241 static inline unsigned long
242 inet_csk_rto_backoff(const struct inet_connection_sock
*icsk
,
243 unsigned long max_when
)
245 u64 when
= (u64
)icsk
->icsk_rto
<< icsk
->icsk_backoff
;
247 return (unsigned long)min_t(u64
, when
, max_when
);
250 struct sock
*inet_csk_accept(struct sock
*sk
, int flags
, int *err
, bool kern
);
252 int inet_csk_get_port(struct sock
*sk
, unsigned short snum
);
254 struct dst_entry
*inet_csk_route_req(const struct sock
*sk
, struct flowi4
*fl4
,
255 const struct request_sock
*req
);
256 struct dst_entry
*inet_csk_route_child_sock(const struct sock
*sk
,
258 const struct request_sock
*req
);
260 struct sock
*inet_csk_reqsk_queue_add(struct sock
*sk
,
261 struct request_sock
*req
,
263 void inet_csk_reqsk_queue_hash_add(struct sock
*sk
, struct request_sock
*req
,
264 unsigned long timeout
);
265 struct sock
*inet_csk_complete_hashdance(struct sock
*sk
, struct sock
*child
,
266 struct request_sock
*req
,
269 static inline void inet_csk_reqsk_queue_added(struct sock
*sk
)
271 reqsk_queue_added(&inet_csk(sk
)->icsk_accept_queue
);
274 static inline int inet_csk_reqsk_queue_len(const struct sock
*sk
)
276 return reqsk_queue_len(&inet_csk(sk
)->icsk_accept_queue
);
279 static inline int inet_csk_reqsk_queue_is_full(const struct sock
*sk
)
281 return inet_csk_reqsk_queue_len(sk
) >= sk
->sk_max_ack_backlog
;
284 void inet_csk_reqsk_queue_drop(struct sock
*sk
, struct request_sock
*req
);
285 void inet_csk_reqsk_queue_drop_and_put(struct sock
*sk
, struct request_sock
*req
);
287 static inline void inet_csk_prepare_for_destroy_sock(struct sock
*sk
)
289 /* The below has to be done to allow calling inet_csk_destroy_sock */
290 sock_set_flag(sk
, SOCK_DEAD
);
291 percpu_counter_inc(sk
->sk_prot
->orphan_count
);
294 void inet_csk_destroy_sock(struct sock
*sk
);
295 void inet_csk_prepare_forced_close(struct sock
*sk
);
298 * LISTEN is a special case for poll..
300 static inline __poll_t
inet_csk_listen_poll(const struct sock
*sk
)
302 return !reqsk_queue_empty(&inet_csk(sk
)->icsk_accept_queue
) ?
303 (EPOLLIN
| EPOLLRDNORM
) : 0;
306 int inet_csk_listen_start(struct sock
*sk
, int backlog
);
307 void inet_csk_listen_stop(struct sock
*sk
);
309 void inet_csk_addr2sockaddr(struct sock
*sk
, struct sockaddr
*uaddr
);
311 /* update the fast reuse flag when adding a socket */
312 void inet_csk_update_fastreuse(struct inet_bind_bucket
*tb
,
315 struct dst_entry
*inet_csk_update_pmtu(struct sock
*sk
, u32 mtu
);
317 #define TCP_PINGPONG_THRESH 3
319 static inline void inet_csk_enter_pingpong_mode(struct sock
*sk
)
321 inet_csk(sk
)->icsk_ack
.pingpong
= TCP_PINGPONG_THRESH
;
324 static inline void inet_csk_exit_pingpong_mode(struct sock
*sk
)
326 inet_csk(sk
)->icsk_ack
.pingpong
= 0;
329 static inline bool inet_csk_in_pingpong_mode(struct sock
*sk
)
331 return inet_csk(sk
)->icsk_ack
.pingpong
>= TCP_PINGPONG_THRESH
;
334 static inline void inet_csk_inc_pingpong_cnt(struct sock
*sk
)
336 struct inet_connection_sock
*icsk
= inet_csk(sk
);
338 if (icsk
->icsk_ack
.pingpong
< U8_MAX
)
339 icsk
->icsk_ack
.pingpong
++;
342 static inline bool inet_csk_has_ulp(struct sock
*sk
)
344 return inet_sk(sk
)->is_icsk
&& !!inet_csk(sk
)->icsk_ulp_ops
;
347 #endif /* _INET_CONNECTION_SOCK_H */