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>
20 #include <net/inet_sock.h>
21 #include <net/request_sock.h>
23 /* Cancel timers, when they are not required. */
24 #undef INET_CSK_CLEAR_TIMERS
26 struct inet_bind_bucket
;
27 struct tcp_congestion_ops
;
30 * Pointers to address related TCP functions
31 * (i.e. things that depend on the address family)
33 struct inet_connection_sock_af_ops
{
34 int (*queue_xmit
)(struct sock
*sk
, struct sk_buff
*skb
, struct flowi
*fl
);
35 void (*send_check
)(struct sock
*sk
, struct sk_buff
*skb
);
36 int (*rebuild_header
)(struct sock
*sk
);
37 void (*sk_rx_dst_set
)(struct sock
*sk
, const struct sk_buff
*skb
);
38 int (*conn_request
)(struct sock
*sk
, struct sk_buff
*skb
);
39 struct sock
*(*syn_recv_sock
)(const struct sock
*sk
, struct sk_buff
*skb
,
40 struct request_sock
*req
,
41 struct dst_entry
*dst
,
42 struct request_sock
*req_unhash
,
45 u16 net_frag_header_len
;
47 int (*setsockopt
)(struct sock
*sk
, int level
, int optname
,
48 char __user
*optval
, unsigned int optlen
);
49 int (*getsockopt
)(struct sock
*sk
, int level
, int optname
,
50 char __user
*optval
, int __user
*optlen
);
52 int (*compat_setsockopt
)(struct sock
*sk
,
53 int level
, int optname
,
54 char __user
*optval
, unsigned int optlen
);
55 int (*compat_getsockopt
)(struct sock
*sk
,
56 int level
, int optname
,
57 char __user
*optval
, int __user
*optlen
);
59 void (*addr2sockaddr
)(struct sock
*sk
, struct sockaddr
*);
60 void (*mtu_reduced
)(struct sock
*sk
);
63 /** inet_connection_sock - INET connection oriented sock
65 * @icsk_accept_queue: FIFO of established children
66 * @icsk_bind_hash: Bind node
67 * @icsk_timeout: Timeout
68 * @icsk_retransmit_timer: Resend (no ack)
69 * @icsk_rto: Retransmit timeout
70 * @icsk_pmtu_cookie Last pmtu seen by socket
71 * @icsk_ca_ops Pluggable congestion control hook
72 * @icsk_af_ops Operations which are AF_INET{4,6} specific
73 * @icsk_ulp_ops Pluggable ULP control hook
74 * @icsk_ulp_data ULP private data
75 * @icsk_clean_acked Clean acked data hook
76 * @icsk_listen_portaddr_node hash to the portaddr listener hashtable
77 * @icsk_ca_state: Congestion control state
78 * @icsk_retransmits: Number of unrecovered [RTO] timeouts
79 * @icsk_pending: Scheduled timer event
80 * @icsk_backoff: Backoff
81 * @icsk_syn_retries: Number of allowed SYN (or equivalent) retries
82 * @icsk_probes_out: unanswered 0 window probes
83 * @icsk_ext_hdr_len: Network protocol overhead (IP/IPv6 options)
84 * @icsk_ack: Delayed ACK control data
85 * @icsk_mtup; MTU probing control data
87 struct inet_connection_sock
{
88 /* inet_sock has to be the first member! */
89 struct inet_sock icsk_inet
;
90 struct request_sock_queue icsk_accept_queue
;
91 struct inet_bind_bucket
*icsk_bind_hash
;
92 unsigned long icsk_timeout
;
93 struct timer_list icsk_retransmit_timer
;
94 struct timer_list icsk_delack_timer
;
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
;
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
:6,
105 icsk_ca_setsockopt
:1,
106 icsk_ca_dst_locked
:1;
107 __u8 icsk_retransmits
;
110 __u8 icsk_syn_retries
;
111 __u8 icsk_probes_out
;
112 __u16 icsk_ext_hdr_len
;
114 __u8 pending
; /* ACK is pending */
115 __u8 quick
; /* Scheduled number of quick acks */
116 __u8 pingpong
; /* The session is interactive */
117 __u8 blocked
; /* Delayed ACK was blocked by socket lock */
118 __u32 ato
; /* Predicted tick of soft clock */
119 unsigned long timeout
; /* Currently scheduled timeout */
120 __u32 lrcvtime
; /* timestamp of last received data packet */
121 __u16 last_seg_size
; /* Size of last incoming segment */
122 __u16 rcv_mss
; /* MSS used for delayed ACK decisions */
127 /* Range of MTUs to search */
131 /* Information on the current probe. */
136 u32 icsk_user_timeout
;
138 u64 icsk_ca_priv
[104 / sizeof(u64
)];
139 #define ICSK_CA_PRIV_SIZE (13 * sizeof(u64))
142 #define ICSK_TIME_RETRANS 1 /* Retransmit timer */
143 #define ICSK_TIME_DACK 2 /* Delayed ack timer */
144 #define ICSK_TIME_PROBE0 3 /* Zero window probe timer */
145 #define ICSK_TIME_EARLY_RETRANS 4 /* Early retransmit timer */
146 #define ICSK_TIME_LOSS_PROBE 5 /* Tail loss probe timer */
147 #define ICSK_TIME_REO_TIMEOUT 6 /* Reordering timer */
149 static inline struct inet_connection_sock
*inet_csk(const struct sock
*sk
)
151 return (struct inet_connection_sock
*)sk
;
154 static inline void *inet_csk_ca(const struct sock
*sk
)
156 return (void *)inet_csk(sk
)->icsk_ca_priv
;
159 struct sock
*inet_csk_clone_lock(const struct sock
*sk
,
160 const struct request_sock
*req
,
161 const gfp_t priority
);
163 enum inet_csk_ack_state_t
{
167 ICSK_ACK_PUSHED2
= 8,
168 ICSK_ACK_NOW
= 16 /* Send the next ACK immediately (once) */
171 void inet_csk_init_xmit_timers(struct sock
*sk
,
172 void (*retransmit_handler
)(struct timer_list
*),
173 void (*delack_handler
)(struct timer_list
*),
174 void (*keepalive_handler
)(struct timer_list
*));
175 void inet_csk_clear_xmit_timers(struct sock
*sk
);
177 static inline void inet_csk_schedule_ack(struct sock
*sk
)
179 inet_csk(sk
)->icsk_ack
.pending
|= ICSK_ACK_SCHED
;
182 static inline int inet_csk_ack_scheduled(const struct sock
*sk
)
184 return inet_csk(sk
)->icsk_ack
.pending
& ICSK_ACK_SCHED
;
187 static inline void inet_csk_delack_init(struct sock
*sk
)
189 memset(&inet_csk(sk
)->icsk_ack
, 0, sizeof(inet_csk(sk
)->icsk_ack
));
192 void inet_csk_delete_keepalive_timer(struct sock
*sk
);
193 void inet_csk_reset_keepalive_timer(struct sock
*sk
, unsigned long timeout
);
195 static inline void inet_csk_clear_xmit_timer(struct sock
*sk
, const int what
)
197 struct inet_connection_sock
*icsk
= inet_csk(sk
);
199 if (what
== ICSK_TIME_RETRANS
|| what
== ICSK_TIME_PROBE0
) {
200 icsk
->icsk_pending
= 0;
201 #ifdef INET_CSK_CLEAR_TIMERS
202 sk_stop_timer(sk
, &icsk
->icsk_retransmit_timer
);
204 } else if (what
== ICSK_TIME_DACK
) {
205 icsk
->icsk_ack
.blocked
= icsk
->icsk_ack
.pending
= 0;
206 #ifdef INET_CSK_CLEAR_TIMERS
207 sk_stop_timer(sk
, &icsk
->icsk_delack_timer
);
210 pr_debug("inet_csk BUG: unknown timer value\n");
215 * Reset the retransmission timer
217 static inline void inet_csk_reset_xmit_timer(struct sock
*sk
, const int what
,
219 const unsigned long max_when
)
221 struct inet_connection_sock
*icsk
= inet_csk(sk
);
223 if (when
> max_when
) {
224 pr_debug("reset_xmit_timer: sk=%p %d when=0x%lx, caller=%p\n",
225 sk
, what
, when
, (void *)_THIS_IP_
);
229 if (what
== ICSK_TIME_RETRANS
|| what
== ICSK_TIME_PROBE0
||
230 what
== ICSK_TIME_EARLY_RETRANS
|| what
== ICSK_TIME_LOSS_PROBE
||
231 what
== ICSK_TIME_REO_TIMEOUT
) {
232 icsk
->icsk_pending
= what
;
233 icsk
->icsk_timeout
= jiffies
+ when
;
234 sk_reset_timer(sk
, &icsk
->icsk_retransmit_timer
, icsk
->icsk_timeout
);
235 } else if (what
== ICSK_TIME_DACK
) {
236 icsk
->icsk_ack
.pending
|= ICSK_ACK_TIMER
;
237 icsk
->icsk_ack
.timeout
= jiffies
+ when
;
238 sk_reset_timer(sk
, &icsk
->icsk_delack_timer
, icsk
->icsk_ack
.timeout
);
240 pr_debug("inet_csk BUG: unknown timer value\n");
244 static inline unsigned long
245 inet_csk_rto_backoff(const struct inet_connection_sock
*icsk
,
246 unsigned long max_when
)
248 u64 when
= (u64
)icsk
->icsk_rto
<< icsk
->icsk_backoff
;
250 return (unsigned long)min_t(u64
, when
, max_when
);
253 struct sock
*inet_csk_accept(struct sock
*sk
, int flags
, int *err
, bool kern
);
255 int inet_csk_get_port(struct sock
*sk
, unsigned short snum
);
257 struct dst_entry
*inet_csk_route_req(const struct sock
*sk
, struct flowi4
*fl4
,
258 const struct request_sock
*req
);
259 struct dst_entry
*inet_csk_route_child_sock(const struct sock
*sk
,
261 const struct request_sock
*req
);
263 struct sock
*inet_csk_reqsk_queue_add(struct sock
*sk
,
264 struct request_sock
*req
,
266 void inet_csk_reqsk_queue_hash_add(struct sock
*sk
, struct request_sock
*req
,
267 unsigned long timeout
);
268 struct sock
*inet_csk_complete_hashdance(struct sock
*sk
, struct sock
*child
,
269 struct request_sock
*req
,
272 static inline void inet_csk_reqsk_queue_added(struct sock
*sk
)
274 reqsk_queue_added(&inet_csk(sk
)->icsk_accept_queue
);
277 static inline int inet_csk_reqsk_queue_len(const struct sock
*sk
)
279 return reqsk_queue_len(&inet_csk(sk
)->icsk_accept_queue
);
282 static inline int inet_csk_reqsk_queue_is_full(const struct sock
*sk
)
284 return inet_csk_reqsk_queue_len(sk
) >= sk
->sk_max_ack_backlog
;
287 void inet_csk_reqsk_queue_drop(struct sock
*sk
, struct request_sock
*req
);
288 void inet_csk_reqsk_queue_drop_and_put(struct sock
*sk
, struct request_sock
*req
);
290 void inet_csk_destroy_sock(struct sock
*sk
);
291 void inet_csk_prepare_forced_close(struct sock
*sk
);
294 * LISTEN is a special case for poll..
296 static inline __poll_t
inet_csk_listen_poll(const struct sock
*sk
)
298 return !reqsk_queue_empty(&inet_csk(sk
)->icsk_accept_queue
) ?
299 (EPOLLIN
| EPOLLRDNORM
) : 0;
302 int inet_csk_listen_start(struct sock
*sk
, int backlog
);
303 void inet_csk_listen_stop(struct sock
*sk
);
305 void inet_csk_addr2sockaddr(struct sock
*sk
, struct sockaddr
*uaddr
);
307 int inet_csk_compat_getsockopt(struct sock
*sk
, int level
, int optname
,
308 char __user
*optval
, int __user
*optlen
);
309 int inet_csk_compat_setsockopt(struct sock
*sk
, int level
, int optname
,
310 char __user
*optval
, unsigned int optlen
);
312 struct dst_entry
*inet_csk_update_pmtu(struct sock
*sk
, u32 mtu
);
314 #define TCP_PINGPONG_THRESH 3
316 static inline void inet_csk_enter_pingpong_mode(struct sock
*sk
)
318 inet_csk(sk
)->icsk_ack
.pingpong
= TCP_PINGPONG_THRESH
;
321 static inline void inet_csk_exit_pingpong_mode(struct sock
*sk
)
323 inet_csk(sk
)->icsk_ack
.pingpong
= 0;
326 static inline bool inet_csk_in_pingpong_mode(struct sock
*sk
)
328 return inet_csk(sk
)->icsk_ack
.pingpong
>= TCP_PINGPONG_THRESH
;
331 static inline void inet_csk_inc_pingpong_cnt(struct sock
*sk
)
333 struct inet_connection_sock
*icsk
= inet_csk(sk
);
335 if (icsk
->icsk_ack
.pingpong
< U8_MAX
)
336 icsk
->icsk_ack
.pingpong
++;
338 #endif /* _INET_CONNECTION_SOCK_H */