2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
6 * Definitions for the TCP module.
8 * Version: @(#)tcp.h 1.0.5 05/23/93
11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
13 * This program is free software; you can redistribute it and/or
14 * modify it under the terms of the GNU General Public License
15 * as published by the Free Software Foundation; either version
16 * 2 of the License, or (at your option) any later version.
22 #define FASTRETRANS_DEBUG 1
24 #include <linux/list.h>
25 #include <linux/tcp.h>
26 #include <linux/slab.h>
27 #include <linux/cache.h>
28 #include <linux/percpu.h>
29 #include <linux/skbuff.h>
30 #include <linux/dmaengine.h>
31 #include <linux/crypto.h>
33 #include <net/inet_connection_sock.h>
34 #include <net/inet_timewait_sock.h>
35 #include <net/inet_hashtables.h>
36 #include <net/checksum.h>
37 #include <net/request_sock.h>
41 #include <net/tcp_states.h>
44 #include <linux/seq_file.h>
46 extern struct inet_hashinfo tcp_hashinfo
;
48 extern atomic_t tcp_orphan_count
;
49 extern void tcp_time_wait(struct sock
*sk
, int state
, int timeo
);
51 #define MAX_TCP_HEADER (128 + MAX_HEADER)
54 * Never offer a window over 32767 without using window scaling. Some
55 * poor stacks do signed 16bit maths!
57 #define MAX_TCP_WINDOW 32767U
59 /* Minimal accepted MSS. It is (60+60+8) - (20+20). */
60 #define TCP_MIN_MSS 88U
62 /* Minimal RCV_MSS. */
63 #define TCP_MIN_RCVMSS 536U
65 /* The least MTU to use for probing */
66 #define TCP_BASE_MSS 512
68 /* After receiving this amount of duplicate ACKs fast retransmit starts. */
69 #define TCP_FASTRETRANS_THRESH 3
71 /* Maximal reordering. */
72 #define TCP_MAX_REORDERING 127
74 /* Maximal number of ACKs sent quickly to accelerate slow-start. */
75 #define TCP_MAX_QUICKACKS 16U
78 #define TCP_URG_VALID 0x0100
79 #define TCP_URG_NOTYET 0x0200
80 #define TCP_URG_READ 0x0400
82 #define TCP_RETR1 3 /*
83 * This is how many retries it does before it
84 * tries to figure out if the gateway is
85 * down. Minimal RFC value is 3; it corresponds
86 * to ~3sec-8min depending on RTO.
89 #define TCP_RETR2 15 /*
90 * This should take at least
91 * 90 minutes to time out.
92 * RFC1122 says that the limit is 100 sec.
93 * 15 is ~13-30min depending on RTO.
96 #define TCP_SYN_RETRIES 5 /* number of times to retry active opening a
97 * connection: ~180sec is RFC minimum */
99 #define TCP_SYNACK_RETRIES 5 /* number of times to retry passive opening a
100 * connection: ~180sec is RFC minimum */
103 #define TCP_ORPHAN_RETRIES 7 /* number of times to retry on an orphaned
104 * socket. 7 is ~50sec-16min.
108 #define TCP_TIMEWAIT_LEN (60*HZ) /* how long to wait to destroy TIME-WAIT
109 * state, about 60 seconds */
110 #define TCP_FIN_TIMEOUT TCP_TIMEWAIT_LEN
111 /* BSD style FIN_WAIT2 deadlock breaker.
112 * It used to be 3min, new value is 60sec,
113 * to combine FIN-WAIT-2 timeout with
117 #define TCP_DELACK_MAX ((unsigned)(HZ/5)) /* maximal time to delay before sending an ACK */
119 #define TCP_DELACK_MIN ((unsigned)(HZ/25)) /* minimal time to delay before sending an ACK */
120 #define TCP_ATO_MIN ((unsigned)(HZ/25))
122 #define TCP_DELACK_MIN 4U
123 #define TCP_ATO_MIN 4U
125 #define TCP_RTO_MAX ((unsigned)(120*HZ))
126 #define TCP_RTO_MIN ((unsigned)(HZ/5))
127 #define TCP_TIMEOUT_INIT ((unsigned)(3*HZ)) /* RFC 1122 initial RTO value */
129 #define TCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ/2U)) /* Maximal interval between probes
130 * for local resources.
133 #define TCP_KEEPALIVE_TIME (120*60*HZ) /* two hours */
134 #define TCP_KEEPALIVE_PROBES 9 /* Max of 9 keepalive probes */
135 #define TCP_KEEPALIVE_INTVL (75*HZ)
137 #define MAX_TCP_KEEPIDLE 32767
138 #define MAX_TCP_KEEPINTVL 32767
139 #define MAX_TCP_KEEPCNT 127
140 #define MAX_TCP_SYNCNT 127
142 #define TCP_SYNQ_INTERVAL (HZ/5) /* Period of SYNACK timer */
144 #define TCP_PAWS_24DAYS (60 * 60 * 24 * 24)
145 #define TCP_PAWS_MSL 60 /* Per-host timestamps are invalidated
146 * after this time. It should be equal
147 * (or greater than) TCP_TIMEWAIT_LEN
148 * to provide reliability equal to one
149 * provided by timewait state.
151 #define TCP_PAWS_WINDOW 1 /* Replay window for per-host
152 * timestamps. It must be less than
153 * minimal timewait lifetime.
159 #define TCPOPT_NOP 1 /* Padding */
160 #define TCPOPT_EOL 0 /* End of options */
161 #define TCPOPT_MSS 2 /* Segment size negotiating */
162 #define TCPOPT_WINDOW 3 /* Window scaling */
163 #define TCPOPT_SACK_PERM 4 /* SACK Permitted */
164 #define TCPOPT_SACK 5 /* SACK Block */
165 #define TCPOPT_TIMESTAMP 8 /* Better RTT estimations/PAWS */
166 #define TCPOPT_MD5SIG 19 /* MD5 Signature (RFC2385) */
172 #define TCPOLEN_MSS 4
173 #define TCPOLEN_WINDOW 3
174 #define TCPOLEN_SACK_PERM 2
175 #define TCPOLEN_TIMESTAMP 10
176 #define TCPOLEN_MD5SIG 18
178 /* But this is what stacks really send out. */
179 #define TCPOLEN_TSTAMP_ALIGNED 12
180 #define TCPOLEN_WSCALE_ALIGNED 4
181 #define TCPOLEN_SACKPERM_ALIGNED 4
182 #define TCPOLEN_SACK_BASE 2
183 #define TCPOLEN_SACK_BASE_ALIGNED 4
184 #define TCPOLEN_SACK_PERBLOCK 8
185 #define TCPOLEN_MD5SIG_ALIGNED 20
187 /* Flags in tp->nonagle */
188 #define TCP_NAGLE_OFF 1 /* Nagle's algo is disabled */
189 #define TCP_NAGLE_CORK 2 /* Socket is corked */
190 #define TCP_NAGLE_PUSH 4 /* Cork is overridden for already queued data */
192 extern struct inet_timewait_death_row tcp_death_row
;
194 /* sysctl variables for tcp */
195 extern int sysctl_tcp_timestamps
;
196 extern int sysctl_tcp_window_scaling
;
197 extern int sysctl_tcp_sack
;
198 extern int sysctl_tcp_fin_timeout
;
199 extern int sysctl_tcp_keepalive_time
;
200 extern int sysctl_tcp_keepalive_probes
;
201 extern int sysctl_tcp_keepalive_intvl
;
202 extern int sysctl_tcp_syn_retries
;
203 extern int sysctl_tcp_synack_retries
;
204 extern int sysctl_tcp_retries1
;
205 extern int sysctl_tcp_retries2
;
206 extern int sysctl_tcp_orphan_retries
;
207 extern int sysctl_tcp_syncookies
;
208 extern int sysctl_tcp_retrans_collapse
;
209 extern int sysctl_tcp_stdurg
;
210 extern int sysctl_tcp_rfc1337
;
211 extern int sysctl_tcp_abort_on_overflow
;
212 extern int sysctl_tcp_max_orphans
;
213 extern int sysctl_tcp_fack
;
214 extern int sysctl_tcp_reordering
;
215 extern int sysctl_tcp_ecn
;
216 extern int sysctl_tcp_dsack
;
217 extern int sysctl_tcp_mem
[3];
218 extern int sysctl_tcp_wmem
[3];
219 extern int sysctl_tcp_rmem
[3];
220 extern int sysctl_tcp_app_win
;
221 extern int sysctl_tcp_adv_win_scale
;
222 extern int sysctl_tcp_tw_reuse
;
223 extern int sysctl_tcp_frto
;
224 extern int sysctl_tcp_frto_response
;
225 extern int sysctl_tcp_low_latency
;
226 extern int sysctl_tcp_dma_copybreak
;
227 extern int sysctl_tcp_nometrics_save
;
228 extern int sysctl_tcp_moderate_rcvbuf
;
229 extern int sysctl_tcp_tso_win_divisor
;
230 extern int sysctl_tcp_abc
;
231 extern int sysctl_tcp_mtu_probing
;
232 extern int sysctl_tcp_base_mss
;
233 extern int sysctl_tcp_workaround_signed_windows
;
234 extern int sysctl_tcp_slow_start_after_idle
;
235 extern int sysctl_tcp_max_ssthresh
;
237 extern atomic_t tcp_memory_allocated
;
238 extern atomic_t tcp_sockets_allocated
;
239 extern int tcp_memory_pressure
;
242 * The next routines deal with comparing 32 bit unsigned ints
243 * and worry about wraparound (automatic with unsigned arithmetic).
246 static inline int before(__u32 seq1
, __u32 seq2
)
248 return (__s32
)(seq1
-seq2
) < 0;
250 #define after(seq2, seq1) before(seq1, seq2)
252 /* is s2<=s1<=s3 ? */
253 static inline int between(__u32 seq1
, __u32 seq2
, __u32 seq3
)
255 return seq3
- seq2
>= seq1
- seq2
;
258 static inline int tcp_too_many_orphans(struct sock
*sk
, int num
)
260 return (num
> sysctl_tcp_max_orphans
) ||
261 (sk
->sk_wmem_queued
> SOCK_MIN_SNDBUF
&&
262 atomic_read(&tcp_memory_allocated
) > sysctl_tcp_mem
[2]);
265 extern struct proto tcp_prot
;
267 DECLARE_SNMP_STAT(struct tcp_mib
, tcp_statistics
);
268 #define TCP_INC_STATS(field) SNMP_INC_STATS(tcp_statistics, field)
269 #define TCP_INC_STATS_BH(field) SNMP_INC_STATS_BH(tcp_statistics, field)
270 #define TCP_INC_STATS_USER(field) SNMP_INC_STATS_USER(tcp_statistics, field)
271 #define TCP_DEC_STATS(field) SNMP_DEC_STATS(tcp_statistics, field)
272 #define TCP_ADD_STATS_BH(field, val) SNMP_ADD_STATS_BH(tcp_statistics, field, val)
273 #define TCP_ADD_STATS_USER(field, val) SNMP_ADD_STATS_USER(tcp_statistics, field, val)
275 extern void tcp_v4_err(struct sk_buff
*skb
, u32
);
277 extern void tcp_shutdown (struct sock
*sk
, int how
);
279 extern int tcp_v4_rcv(struct sk_buff
*skb
);
281 extern int tcp_v4_remember_stamp(struct sock
*sk
);
283 extern int tcp_v4_tw_remember_stamp(struct inet_timewait_sock
*tw
);
285 extern int tcp_sendmsg(struct kiocb
*iocb
, struct socket
*sock
,
286 struct msghdr
*msg
, size_t size
);
287 extern ssize_t
tcp_sendpage(struct socket
*sock
, struct page
*page
, int offset
, size_t size
, int flags
);
289 extern int tcp_ioctl(struct sock
*sk
,
293 extern int tcp_rcv_state_process(struct sock
*sk
,
298 extern int tcp_rcv_established(struct sock
*sk
,
303 extern void tcp_rcv_space_adjust(struct sock
*sk
);
305 extern void tcp_cleanup_rbuf(struct sock
*sk
, int copied
);
307 extern int tcp_twsk_unique(struct sock
*sk
,
308 struct sock
*sktw
, void *twp
);
310 extern void tcp_twsk_destructor(struct sock
*sk
);
312 extern ssize_t
tcp_splice_read(struct socket
*sk
, loff_t
*ppos
,
313 struct pipe_inode_info
*pipe
, size_t len
, unsigned int flags
);
315 static inline void tcp_dec_quickack_mode(struct sock
*sk
,
316 const unsigned int pkts
)
318 struct inet_connection_sock
*icsk
= inet_csk(sk
);
320 if (icsk
->icsk_ack
.quick
) {
321 if (pkts
>= icsk
->icsk_ack
.quick
) {
322 icsk
->icsk_ack
.quick
= 0;
323 /* Leaving quickack mode we deflate ATO. */
324 icsk
->icsk_ack
.ato
= TCP_ATO_MIN
;
326 icsk
->icsk_ack
.quick
-= pkts
;
330 extern void tcp_enter_quickack_mode(struct sock
*sk
);
332 static inline void tcp_clear_options(struct tcp_options_received
*rx_opt
)
334 rx_opt
->tstamp_ok
= rx_opt
->sack_ok
= rx_opt
->wscale_ok
= rx_opt
->snd_wscale
= 0;
346 extern enum tcp_tw_status
tcp_timewait_state_process(struct inet_timewait_sock
*tw
,
348 const struct tcphdr
*th
);
350 extern struct sock
* tcp_check_req(struct sock
*sk
,struct sk_buff
*skb
,
351 struct request_sock
*req
,
352 struct request_sock
**prev
);
353 extern int tcp_child_process(struct sock
*parent
,
355 struct sk_buff
*skb
);
356 extern int tcp_use_frto(struct sock
*sk
);
357 extern void tcp_enter_frto(struct sock
*sk
);
358 extern void tcp_enter_loss(struct sock
*sk
, int how
);
359 extern void tcp_clear_retrans(struct tcp_sock
*tp
);
360 extern void tcp_update_metrics(struct sock
*sk
);
362 extern void tcp_close(struct sock
*sk
,
364 extern unsigned int tcp_poll(struct file
* file
, struct socket
*sock
, struct poll_table_struct
*wait
);
366 extern int tcp_getsockopt(struct sock
*sk
, int level
,
370 extern int tcp_setsockopt(struct sock
*sk
, int level
,
371 int optname
, char __user
*optval
,
373 extern int compat_tcp_getsockopt(struct sock
*sk
,
374 int level
, int optname
,
375 char __user
*optval
, int __user
*optlen
);
376 extern int compat_tcp_setsockopt(struct sock
*sk
,
377 int level
, int optname
,
378 char __user
*optval
, int optlen
);
379 extern void tcp_set_keepalive(struct sock
*sk
, int val
);
380 extern int tcp_recvmsg(struct kiocb
*iocb
, struct sock
*sk
,
382 size_t len
, int nonblock
,
383 int flags
, int *addr_len
);
385 extern void tcp_parse_options(struct sk_buff
*skb
,
386 struct tcp_options_received
*opt_rx
,
390 * TCP v4 functions exported for the inet6 API
393 extern void tcp_v4_send_check(struct sock
*sk
, int len
,
394 struct sk_buff
*skb
);
396 extern int tcp_v4_conn_request(struct sock
*sk
,
397 struct sk_buff
*skb
);
399 extern struct sock
* tcp_create_openreq_child(struct sock
*sk
,
400 struct request_sock
*req
,
401 struct sk_buff
*skb
);
403 extern struct sock
* tcp_v4_syn_recv_sock(struct sock
*sk
,
405 struct request_sock
*req
,
406 struct dst_entry
*dst
);
408 extern int tcp_v4_do_rcv(struct sock
*sk
,
409 struct sk_buff
*skb
);
411 extern int tcp_v4_connect(struct sock
*sk
,
412 struct sockaddr
*uaddr
,
415 extern int tcp_connect(struct sock
*sk
);
417 extern struct sk_buff
* tcp_make_synack(struct sock
*sk
,
418 struct dst_entry
*dst
,
419 struct request_sock
*req
);
421 extern int tcp_disconnect(struct sock
*sk
, int flags
);
423 extern void tcp_unhash(struct sock
*sk
);
425 /* From syncookies.c */
426 extern struct sock
*cookie_v4_check(struct sock
*sk
, struct sk_buff
*skb
,
427 struct ip_options
*opt
);
428 extern __u32
cookie_v4_init_sequence(struct sock
*sk
, struct sk_buff
*skb
,
433 extern void __tcp_push_pending_frames(struct sock
*sk
, unsigned int cur_mss
,
435 extern int tcp_may_send_now(struct sock
*sk
);
436 extern int tcp_retransmit_skb(struct sock
*, struct sk_buff
*);
437 extern void tcp_xmit_retransmit_queue(struct sock
*);
438 extern void tcp_simple_retransmit(struct sock
*);
439 extern int tcp_trim_head(struct sock
*, struct sk_buff
*, u32
);
440 extern int tcp_fragment(struct sock
*, struct sk_buff
*, u32
, unsigned int);
442 extern void tcp_send_probe0(struct sock
*);
443 extern void tcp_send_partial(struct sock
*);
444 extern int tcp_write_wakeup(struct sock
*);
445 extern void tcp_send_fin(struct sock
*sk
);
446 extern void tcp_send_active_reset(struct sock
*sk
, gfp_t priority
);
447 extern int tcp_send_synack(struct sock
*);
448 extern void tcp_push_one(struct sock
*, unsigned int mss_now
);
449 extern void tcp_send_ack(struct sock
*sk
);
450 extern void tcp_send_delayed_ack(struct sock
*sk
);
453 extern void tcp_cwnd_application_limited(struct sock
*sk
);
456 extern void tcp_init_xmit_timers(struct sock
*);
457 static inline void tcp_clear_xmit_timers(struct sock
*sk
)
459 inet_csk_clear_xmit_timers(sk
);
462 extern unsigned int tcp_sync_mss(struct sock
*sk
, u32 pmtu
);
463 extern unsigned int tcp_current_mss(struct sock
*sk
, int large
);
466 extern void tcp_get_info(struct sock
*, struct tcp_info
*);
468 /* Read 'sendfile()'-style from a TCP socket */
469 typedef int (*sk_read_actor_t
)(read_descriptor_t
*, struct sk_buff
*,
470 unsigned int, size_t);
471 extern int tcp_read_sock(struct sock
*sk
, read_descriptor_t
*desc
,
472 sk_read_actor_t recv_actor
);
474 extern void tcp_initialize_rcv_mss(struct sock
*sk
);
476 extern int tcp_mtu_to_mss(struct sock
*sk
, int pmtu
);
477 extern int tcp_mss_to_mtu(struct sock
*sk
, int mss
);
478 extern void tcp_mtup_init(struct sock
*sk
);
480 static inline void __tcp_fast_path_on(struct tcp_sock
*tp
, u32 snd_wnd
)
482 tp
->pred_flags
= htonl((tp
->tcp_header_len
<< 26) |
483 ntohl(TCP_FLAG_ACK
) |
487 static inline void tcp_fast_path_on(struct tcp_sock
*tp
)
489 __tcp_fast_path_on(tp
, tp
->snd_wnd
>> tp
->rx_opt
.snd_wscale
);
492 static inline void tcp_fast_path_check(struct sock
*sk
)
494 struct tcp_sock
*tp
= tcp_sk(sk
);
496 if (skb_queue_empty(&tp
->out_of_order_queue
) &&
498 atomic_read(&sk
->sk_rmem_alloc
) < sk
->sk_rcvbuf
&&
500 tcp_fast_path_on(tp
);
503 /* Compute the actual rto_min value */
504 static inline u32
tcp_rto_min(struct sock
*sk
)
506 struct dst_entry
*dst
= __sk_dst_get(sk
);
507 u32 rto_min
= TCP_RTO_MIN
;
509 if (dst
&& dst_metric_locked(dst
, RTAX_RTO_MIN
))
510 rto_min
= dst_metric_rtt(dst
, RTAX_RTO_MIN
);
514 /* Compute the actual receive window we are currently advertising.
515 * Rcv_nxt can be after the window if our peer push more data
516 * than the offered window.
518 static inline u32
tcp_receive_window(const struct tcp_sock
*tp
)
520 s32 win
= tp
->rcv_wup
+ tp
->rcv_wnd
- tp
->rcv_nxt
;
527 /* Choose a new window, without checks for shrinking, and without
528 * scaling applied to the result. The caller does these things
529 * if necessary. This is a "raw" window selection.
531 extern u32
__tcp_select_window(struct sock
*sk
);
533 /* TCP timestamps are only 32-bits, this causes a slight
534 * complication on 64-bit systems since we store a snapshot
535 * of jiffies in the buffer control blocks below. We decided
536 * to use only the low 32-bits of jiffies and hide the ugly
537 * casts with the following macro.
539 #define tcp_time_stamp ((__u32)(jiffies))
541 /* This is what the send packet queuing engine uses to pass
542 * TCP per-packet control information to the transmission
543 * code. We also store the host-order sequence numbers in
544 * here too. This is 36 bytes on 32-bit architectures,
545 * 40 bytes on 64-bit machines, if this grows please adjust
546 * skbuff.h:skbuff->cb[xxx] size appropriately.
550 struct inet_skb_parm h4
;
551 #if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
552 struct inet6_skb_parm h6
;
554 } header
; /* For incoming frames */
555 __u32 seq
; /* Starting sequence number */
556 __u32 end_seq
; /* SEQ + FIN + SYN + datalen */
557 __u32 when
; /* used to compute rtt's */
558 __u8 flags
; /* TCP header flags. */
560 /* NOTE: These must match up to the flags byte in a
563 #define TCPCB_FLAG_FIN 0x01
564 #define TCPCB_FLAG_SYN 0x02
565 #define TCPCB_FLAG_RST 0x04
566 #define TCPCB_FLAG_PSH 0x08
567 #define TCPCB_FLAG_ACK 0x10
568 #define TCPCB_FLAG_URG 0x20
569 #define TCPCB_FLAG_ECE 0x40
570 #define TCPCB_FLAG_CWR 0x80
572 __u8 sacked
; /* State flags for SACK/FACK. */
573 #define TCPCB_SACKED_ACKED 0x01 /* SKB ACK'd by a SACK block */
574 #define TCPCB_SACKED_RETRANS 0x02 /* SKB retransmitted */
575 #define TCPCB_LOST 0x04 /* SKB is lost */
576 #define TCPCB_TAGBITS 0x07 /* All tag bits */
578 #define TCPCB_EVER_RETRANS 0x80 /* Ever retransmitted frame */
579 #define TCPCB_RETRANS (TCPCB_SACKED_RETRANS|TCPCB_EVER_RETRANS)
581 #define TCPCB_URG 0x20 /* Urgent pointer advanced here */
583 #define TCPCB_AT_TAIL (TCPCB_URG)
585 __u16 urg_ptr
; /* Valid w/URG flags is set. */
586 __u32 ack_seq
; /* Sequence number ACK'd */
589 #define TCP_SKB_CB(__skb) ((struct tcp_skb_cb *)&((__skb)->cb[0]))
591 #include <net/tcp_ecn.h>
593 /* Due to TSO, an SKB can be composed of multiple actual
594 * packets. To keep these tracked properly, we use this.
596 static inline int tcp_skb_pcount(const struct sk_buff
*skb
)
598 return skb_shinfo(skb
)->gso_segs
;
601 /* This is valid iff tcp_skb_pcount() > 1. */
602 static inline int tcp_skb_mss(const struct sk_buff
*skb
)
604 return skb_shinfo(skb
)->gso_size
;
607 static inline void tcp_dec_pcount_approx(__u32
*count
,
608 const struct sk_buff
*skb
)
611 *count
-= tcp_skb_pcount(skb
);
617 static inline void tcp_packets_out_inc(struct sock
*sk
,
618 const struct sk_buff
*skb
)
620 struct tcp_sock
*tp
= tcp_sk(sk
);
621 int orig
= tp
->packets_out
;
623 tp
->packets_out
+= tcp_skb_pcount(skb
);
625 inet_csk_reset_xmit_timer(sk
, ICSK_TIME_RETRANS
,
626 inet_csk(sk
)->icsk_rto
, TCP_RTO_MAX
);
629 static inline void tcp_packets_out_dec(struct tcp_sock
*tp
,
630 const struct sk_buff
*skb
)
632 tp
->packets_out
-= tcp_skb_pcount(skb
);
635 /* Events passed to congestion control interface */
637 CA_EVENT_TX_START
, /* first transmit when no packets in flight */
638 CA_EVENT_CWND_RESTART
, /* congestion window restart */
639 CA_EVENT_COMPLETE_CWR
, /* end of congestion recovery */
640 CA_EVENT_FRTO
, /* fast recovery timeout */
641 CA_EVENT_LOSS
, /* loss timeout */
642 CA_EVENT_FAST_ACK
, /* in sequence ack */
643 CA_EVENT_SLOW_ACK
, /* other ack */
647 * Interface for adding new TCP congestion control handlers
649 #define TCP_CA_NAME_MAX 16
650 #define TCP_CA_MAX 128
651 #define TCP_CA_BUF_MAX (TCP_CA_NAME_MAX*TCP_CA_MAX)
653 #define TCP_CONG_NON_RESTRICTED 0x1
654 #define TCP_CONG_RTT_STAMP 0x2
656 struct tcp_congestion_ops
{
657 struct list_head list
;
660 /* initialize private data (optional) */
661 void (*init
)(struct sock
*sk
);
662 /* cleanup private data (optional) */
663 void (*release
)(struct sock
*sk
);
665 /* return slow start threshold (required) */
666 u32 (*ssthresh
)(struct sock
*sk
);
667 /* lower bound for congestion window (optional) */
668 u32 (*min_cwnd
)(const struct sock
*sk
);
669 /* do new cwnd calculation (required) */
670 void (*cong_avoid
)(struct sock
*sk
, u32 ack
,
671 u32 rtt
, u32 in_flight
, int good_ack
);
672 /* call before changing ca_state (optional) */
673 void (*set_state
)(struct sock
*sk
, u8 new_state
);
674 /* call when cwnd event occurs (optional) */
675 void (*cwnd_event
)(struct sock
*sk
, enum tcp_ca_event ev
);
676 /* new value of cwnd after loss (optional) */
677 u32 (*undo_cwnd
)(struct sock
*sk
);
678 /* hook for packet ack accounting (optional) */
679 void (*pkts_acked
)(struct sock
*sk
, u32 num_acked
, ktime_t last
);
680 /* get info for inet_diag (optional) */
681 void (*get_info
)(struct sock
*sk
, u32 ext
, struct sk_buff
*skb
);
683 char name
[TCP_CA_NAME_MAX
];
684 struct module
*owner
;
687 extern int tcp_register_congestion_control(struct tcp_congestion_ops
*type
);
688 extern void tcp_unregister_congestion_control(struct tcp_congestion_ops
*type
);
690 extern void tcp_init_congestion_control(struct sock
*sk
);
691 extern void tcp_cleanup_congestion_control(struct sock
*sk
);
692 extern int tcp_set_default_congestion_control(const char *name
);
693 extern void tcp_get_default_congestion_control(char *name
);
694 extern void tcp_get_available_congestion_control(char *buf
, size_t len
);
695 extern void tcp_get_allowed_congestion_control(char *buf
, size_t len
);
696 extern int tcp_set_allowed_congestion_control(char *allowed
);
697 extern int tcp_set_congestion_control(struct sock
*sk
, const char *name
);
698 extern void tcp_slow_start(struct tcp_sock
*tp
);
700 extern struct tcp_congestion_ops tcp_init_congestion_ops
;
701 extern u32
tcp_reno_ssthresh(struct sock
*sk
);
702 extern void tcp_reno_cong_avoid(struct sock
*sk
, u32 ack
,
703 u32 rtt
, u32 in_flight
, int flag
);
704 extern u32
tcp_reno_min_cwnd(const struct sock
*sk
);
705 extern struct tcp_congestion_ops tcp_reno
;
707 static inline void tcp_set_ca_state(struct sock
*sk
, const u8 ca_state
)
709 struct inet_connection_sock
*icsk
= inet_csk(sk
);
711 if (icsk
->icsk_ca_ops
->set_state
)
712 icsk
->icsk_ca_ops
->set_state(sk
, ca_state
);
713 icsk
->icsk_ca_state
= ca_state
;
716 static inline void tcp_ca_event(struct sock
*sk
, const enum tcp_ca_event event
)
718 const struct inet_connection_sock
*icsk
= inet_csk(sk
);
720 if (icsk
->icsk_ca_ops
->cwnd_event
)
721 icsk
->icsk_ca_ops
->cwnd_event(sk
, event
);
724 /* This determines how many packets are "in the network" to the best
725 * of our knowledge. In many cases it is conservative, but where
726 * detailed information is available from the receiver (via SACK
727 * blocks etc.) we can make more aggressive calculations.
729 * Use this for decisions involving congestion control, use just
730 * tp->packets_out to determine if the send queue is empty or not.
732 * Read this equation as:
734 * "Packets sent once on transmission queue" MINUS
735 * "Packets left network, but not honestly ACKed yet" PLUS
736 * "Packets fast retransmitted"
738 static inline unsigned int tcp_packets_in_flight(const struct tcp_sock
*tp
)
740 return (tp
->packets_out
- tp
->left_out
+ tp
->retrans_out
);
743 /* If cwnd > ssthresh, we may raise ssthresh to be half-way to cwnd.
744 * The exception is rate halving phase, when cwnd is decreasing towards
747 static inline __u32
tcp_current_ssthresh(const struct sock
*sk
)
749 const struct tcp_sock
*tp
= tcp_sk(sk
);
750 if ((1 << inet_csk(sk
)->icsk_ca_state
) & (TCPF_CA_CWR
| TCPF_CA_Recovery
))
751 return tp
->snd_ssthresh
;
753 return max(tp
->snd_ssthresh
,
754 ((tp
->snd_cwnd
>> 1) +
755 (tp
->snd_cwnd
>> 2)));
758 static inline void tcp_sync_left_out(struct tcp_sock
*tp
)
760 WARN_ON(tp
->rx_opt
.sack_ok
&&
761 (tp
->sacked_out
+ tp
->lost_out
> tp
->packets_out
));
762 tp
->left_out
= tp
->sacked_out
+ tp
->lost_out
;
765 extern void tcp_enter_cwr(struct sock
*sk
, const int set_ssthresh
);
766 extern __u32
tcp_init_cwnd(struct tcp_sock
*tp
, struct dst_entry
*dst
);
768 /* Slow start with delack produces 3 packets of burst, so that
769 * it is safe "de facto".
771 static __inline__ __u32
tcp_max_burst(const struct tcp_sock
*tp
)
776 /* RFC2861 Check whether we are limited by application or congestion window
777 * This is the inverse of cwnd check in tcp_tso_should_defer
779 static inline int tcp_is_cwnd_limited(const struct sock
*sk
, u32 in_flight
)
781 const struct tcp_sock
*tp
= tcp_sk(sk
);
784 if (in_flight
>= tp
->snd_cwnd
)
790 left
= tp
->snd_cwnd
- in_flight
;
791 if (sysctl_tcp_tso_win_divisor
)
792 return left
* sysctl_tcp_tso_win_divisor
< tp
->snd_cwnd
;
794 return left
<= tcp_max_burst(tp
);
797 static inline void tcp_minshall_update(struct tcp_sock
*tp
, int mss
,
798 const struct sk_buff
*skb
)
801 tp
->snd_sml
= TCP_SKB_CB(skb
)->end_seq
;
804 static inline void tcp_check_probe_timer(struct sock
*sk
)
806 struct tcp_sock
*tp
= tcp_sk(sk
);
807 const struct inet_connection_sock
*icsk
= inet_csk(sk
);
809 if (!tp
->packets_out
&& !icsk
->icsk_pending
)
810 inet_csk_reset_xmit_timer(sk
, ICSK_TIME_PROBE0
,
811 icsk
->icsk_rto
, TCP_RTO_MAX
);
814 static inline void tcp_push_pending_frames(struct sock
*sk
)
816 struct tcp_sock
*tp
= tcp_sk(sk
);
818 __tcp_push_pending_frames(sk
, tcp_current_mss(sk
, 1), tp
->nonagle
);
821 static inline void tcp_init_wl(struct tcp_sock
*tp
, u32 ack
, u32 seq
)
826 static inline void tcp_update_wl(struct tcp_sock
*tp
, u32 ack
, u32 seq
)
832 * Calculate(/check) TCP checksum
834 static inline __sum16
tcp_v4_check(int len
, __be32 saddr
,
835 __be32 daddr
, __wsum base
)
837 return csum_tcpudp_magic(saddr
,daddr
,len
,IPPROTO_TCP
,base
);
840 static inline __sum16
__tcp_checksum_complete(struct sk_buff
*skb
)
842 return __skb_checksum_complete(skb
);
845 static inline int tcp_checksum_complete(struct sk_buff
*skb
)
847 return !skb_csum_unnecessary(skb
) &&
848 __tcp_checksum_complete(skb
);
851 /* Prequeue for VJ style copy to user, combined with checksumming. */
853 static inline void tcp_prequeue_init(struct tcp_sock
*tp
)
855 tp
->ucopy
.task
= NULL
;
857 tp
->ucopy
.memory
= 0;
858 skb_queue_head_init(&tp
->ucopy
.prequeue
);
859 #ifdef CONFIG_NET_DMA
860 tp
->ucopy
.dma_chan
= NULL
;
861 tp
->ucopy
.wakeup
= 0;
862 tp
->ucopy
.pinned_list
= NULL
;
863 tp
->ucopy
.dma_cookie
= 0;
867 /* Packet is added to VJ-style prequeue for processing in process
868 * context, if a reader task is waiting. Apparently, this exciting
869 * idea (VJ's mail "Re: query about TCP header on tcp-ip" of 07 Sep 93)
870 * failed somewhere. Latency? Burstiness? Well, at least now we will
871 * see, why it failed. 8)8) --ANK
873 * NOTE: is this not too big to inline?
875 static inline int tcp_prequeue(struct sock
*sk
, struct sk_buff
*skb
)
877 struct tcp_sock
*tp
= tcp_sk(sk
);
879 if (!sysctl_tcp_low_latency
&& tp
->ucopy
.task
) {
880 __skb_queue_tail(&tp
->ucopy
.prequeue
, skb
);
881 tp
->ucopy
.memory
+= skb
->truesize
;
882 if (tp
->ucopy
.memory
> sk
->sk_rcvbuf
) {
883 struct sk_buff
*skb1
;
885 BUG_ON(sock_owned_by_user(sk
));
887 while ((skb1
= __skb_dequeue(&tp
->ucopy
.prequeue
)) != NULL
) {
888 sk
->sk_backlog_rcv(sk
, skb1
);
889 NET_INC_STATS_BH(LINUX_MIB_TCPPREQUEUEDROPPED
);
892 tp
->ucopy
.memory
= 0;
893 } else if (skb_queue_len(&tp
->ucopy
.prequeue
) == 1) {
894 wake_up_interruptible(sk
->sk_sleep
);
895 if (!inet_csk_ack_scheduled(sk
))
896 inet_csk_reset_xmit_timer(sk
, ICSK_TIME_DACK
,
897 (3 * tcp_rto_min(sk
)) / 4,
909 static const char *statename
[]={
910 "Unused","Established","Syn Sent","Syn Recv",
911 "Fin Wait 1","Fin Wait 2","Time Wait", "Close",
912 "Close Wait","Last ACK","Listen","Closing"
915 extern void tcp_set_state(struct sock
*sk
, int state
);
917 extern void tcp_done(struct sock
*sk
);
919 static inline void tcp_sack_reset(struct tcp_options_received
*rx_opt
)
922 rx_opt
->eff_sacks
= 0;
923 rx_opt
->num_sacks
= 0;
926 /* Determine a window scaling and initial window to offer. */
927 extern void tcp_select_initial_window(int __space
, __u32 mss
,
928 __u32
*rcv_wnd
, __u32
*window_clamp
,
929 int wscale_ok
, __u8
*rcv_wscale
);
931 static inline int tcp_win_from_space(int space
)
933 return sysctl_tcp_adv_win_scale
<=0 ?
934 (space
>>(-sysctl_tcp_adv_win_scale
)) :
935 space
- (space
>>sysctl_tcp_adv_win_scale
);
938 /* Note: caller must be prepared to deal with negative returns */
939 static inline int tcp_space(const struct sock
*sk
)
941 return tcp_win_from_space(sk
->sk_rcvbuf
-
942 atomic_read(&sk
->sk_rmem_alloc
));
945 static inline int tcp_full_space(const struct sock
*sk
)
947 return tcp_win_from_space(sk
->sk_rcvbuf
);
950 static inline void tcp_openreq_init(struct request_sock
*req
,
951 struct tcp_options_received
*rx_opt
,
954 struct inet_request_sock
*ireq
= inet_rsk(req
);
956 req
->rcv_wnd
= 0; /* So that tcp_send_synack() knows! */
957 tcp_rsk(req
)->rcv_isn
= TCP_SKB_CB(skb
)->seq
;
958 req
->mss
= rx_opt
->mss_clamp
;
959 req
->ts_recent
= rx_opt
->saw_tstamp
? rx_opt
->rcv_tsval
: 0;
960 ireq
->tstamp_ok
= rx_opt
->tstamp_ok
;
961 ireq
->sack_ok
= rx_opt
->sack_ok
;
962 ireq
->snd_wscale
= rx_opt
->snd_wscale
;
963 ireq
->wscale_ok
= rx_opt
->wscale_ok
;
966 ireq
->rmt_port
= tcp_hdr(skb
)->source
;
969 extern void tcp_enter_memory_pressure(void);
971 static inline int keepalive_intvl_when(const struct tcp_sock
*tp
)
973 return tp
->keepalive_intvl
? : sysctl_tcp_keepalive_intvl
;
976 static inline int keepalive_time_when(const struct tcp_sock
*tp
)
978 return tp
->keepalive_time
? : sysctl_tcp_keepalive_time
;
981 static inline u32
keepalive_time_elapsed(const struct tcp_sock
*tp
)
983 const struct inet_connection_sock
*icsk
= &tp
->inet_conn
;
985 return min_t(u32
, tcp_time_stamp
- icsk
->icsk_ack
.lrcvtime
,
986 tcp_time_stamp
- tp
->rcv_tstamp
);
989 static inline int tcp_fin_time(const struct sock
*sk
)
991 int fin_timeout
= tcp_sk(sk
)->linger2
? : sysctl_tcp_fin_timeout
;
992 const int rto
= inet_csk(sk
)->icsk_rto
;
994 if (fin_timeout
< (rto
<< 2) - (rto
>> 1))
995 fin_timeout
= (rto
<< 2) - (rto
>> 1);
1000 static inline int tcp_paws_check(const struct tcp_options_received
*rx_opt
,
1003 if ((s32
)(rx_opt
->ts_recent
- rx_opt
->rcv_tsval
) <= paws_win
)
1005 if (unlikely(get_seconds() >= rx_opt
->ts_recent_stamp
+ TCP_PAWS_24DAYS
))
1008 * Some OSes send SYN and SYNACK messages with tsval=0 tsecr=0,
1009 * then following tcp messages have valid values. Ignore 0 value,
1010 * or else 'negative' tsval might forbid us to accept their packets.
1012 if (!rx_opt
->ts_recent
)
1017 static inline int tcp_paws_reject(const struct tcp_options_received
*rx_opt
,
1020 if (tcp_paws_check(rx_opt
, 0))
1023 /* RST segments are not recommended to carry timestamp,
1024 and, if they do, it is recommended to ignore PAWS because
1025 "their cleanup function should take precedence over timestamps."
1026 Certainly, it is mistake. It is necessary to understand the reasons
1027 of this constraint to relax it: if peer reboots, clock may go
1028 out-of-sync and half-open connections will not be reset.
1029 Actually, the problem would be not existing if all
1030 the implementations followed draft about maintaining clock
1031 via reboots. Linux-2.2 DOES NOT!
1033 However, we can relax time bounds for RST segments to MSL.
1035 if (rst
&& get_seconds() >= rx_opt
->ts_recent_stamp
+ TCP_PAWS_MSL
)
1040 #define TCP_CHECK_TIMER(sk) do { } while (0)
1042 static inline void tcp_mib_init(void)
1045 TCP_ADD_STATS_USER(TCP_MIB_RTOALGORITHM
, 1);
1046 TCP_ADD_STATS_USER(TCP_MIB_RTOMIN
, TCP_RTO_MIN
*1000/HZ
);
1047 TCP_ADD_STATS_USER(TCP_MIB_RTOMAX
, TCP_RTO_MAX
*1000/HZ
);
1048 TCP_ADD_STATS_USER(TCP_MIB_MAXCONN
, -1);
1052 static inline void clear_all_retrans_hints(struct tcp_sock
*tp
){
1053 tp
->lost_skb_hint
= NULL
;
1054 tp
->scoreboard_skb_hint
= NULL
;
1055 tp
->retransmit_skb_hint
= NULL
;
1056 tp
->forward_skb_hint
= NULL
;
1057 tp
->fastpath_skb_hint
= NULL
;
1063 /* - key database */
1064 struct tcp_md5sig_key
{
1069 struct tcp4_md5sig_key
{
1070 struct tcp_md5sig_key base
;
1074 struct tcp6_md5sig_key
{
1075 struct tcp_md5sig_key base
;
1077 u32 scope_id
; /* XXX */
1079 struct in6_addr addr
;
1083 struct tcp_md5sig_info
{
1084 struct tcp4_md5sig_key
*keys4
;
1085 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1086 struct tcp6_md5sig_key
*keys6
;
1094 /* - pseudo header */
1095 struct tcp4_pseudohdr
{
1103 struct tcp6_pseudohdr
{
1104 struct in6_addr saddr
;
1105 struct in6_addr daddr
;
1107 __be32 protocol
; /* including padding */
1110 union tcp_md5sum_block
{
1111 struct tcp4_pseudohdr ip4
;
1112 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
1113 struct tcp6_pseudohdr ip6
;
1117 /* - pool: digest algorithm, hash description and scratch buffer */
1118 struct tcp_md5sig_pool
{
1119 struct hash_desc md5_desc
;
1120 union tcp_md5sum_block md5_blk
;
1123 #define TCP_MD5SIG_MAXKEYS (~(u32)0) /* really?! */
1126 extern int tcp_v4_calc_md5_hash(char *md5_hash
,
1127 struct tcp_md5sig_key
*key
,
1129 struct dst_entry
*dst
,
1130 struct request_sock
*req
,
1132 int protocol
, int tcplen
);
1133 extern struct tcp_md5sig_key
*tcp_v4_md5_lookup(struct sock
*sk
,
1134 struct sock
*addr_sk
);
1136 extern int tcp_v4_md5_do_add(struct sock
*sk
,
1141 extern int tcp_v4_md5_do_del(struct sock
*sk
,
1144 extern struct tcp_md5sig_pool
**tcp_alloc_md5sig_pool(void);
1145 extern void tcp_free_md5sig_pool(void);
1147 extern struct tcp_md5sig_pool
*__tcp_get_md5sig_pool(int cpu
);
1148 extern void __tcp_put_md5sig_pool(void);
1151 struct tcp_md5sig_pool
*tcp_get_md5sig_pool(void)
1153 int cpu
= get_cpu();
1154 struct tcp_md5sig_pool
*ret
= __tcp_get_md5sig_pool(cpu
);
1160 static inline void tcp_put_md5sig_pool(void)
1162 __tcp_put_md5sig_pool();
1166 /* write queue abstraction */
1167 static inline void tcp_write_queue_purge(struct sock
*sk
)
1169 struct sk_buff
*skb
;
1171 while ((skb
= __skb_dequeue(&sk
->sk_write_queue
)) != NULL
)
1172 sk_stream_free_skb(sk
, skb
);
1173 sk_stream_mem_reclaim(sk
);
1176 static inline struct sk_buff
*tcp_write_queue_head(struct sock
*sk
)
1178 struct sk_buff
*skb
= sk
->sk_write_queue
.next
;
1179 if (skb
== (struct sk_buff
*) &sk
->sk_write_queue
)
1184 static inline struct sk_buff
*tcp_write_queue_tail(struct sock
*sk
)
1186 struct sk_buff
*skb
= sk
->sk_write_queue
.prev
;
1187 if (skb
== (struct sk_buff
*) &sk
->sk_write_queue
)
1192 static inline struct sk_buff
*tcp_write_queue_next(struct sock
*sk
, struct sk_buff
*skb
)
1197 #define tcp_for_write_queue(skb, sk) \
1198 for (skb = (sk)->sk_write_queue.next; \
1199 (skb != (struct sk_buff *)&(sk)->sk_write_queue); \
1202 #define tcp_for_write_queue_from(skb, sk) \
1203 for (; (skb != (struct sk_buff *)&(sk)->sk_write_queue);\
1206 static inline struct sk_buff
*tcp_send_head(struct sock
*sk
)
1208 return sk
->sk_send_head
;
1211 static inline void tcp_advance_send_head(struct sock
*sk
, struct sk_buff
*skb
)
1213 struct tcp_sock
*tp
= tcp_sk(sk
);
1215 sk
->sk_send_head
= skb
->next
;
1216 if (sk
->sk_send_head
== (struct sk_buff
*)&sk
->sk_write_queue
)
1217 sk
->sk_send_head
= NULL
;
1218 /* Don't override Nagle indefinately with F-RTO */
1219 if (tp
->frto_counter
== 2)
1220 tp
->frto_counter
= 3;
1223 static inline void tcp_check_send_head(struct sock
*sk
, struct sk_buff
*skb_unlinked
)
1225 if (sk
->sk_send_head
== skb_unlinked
)
1226 sk
->sk_send_head
= NULL
;
1229 static inline void tcp_init_send_head(struct sock
*sk
)
1231 sk
->sk_send_head
= NULL
;
1234 static inline void __tcp_add_write_queue_tail(struct sock
*sk
, struct sk_buff
*skb
)
1236 __skb_queue_tail(&sk
->sk_write_queue
, skb
);
1239 static inline void tcp_add_write_queue_tail(struct sock
*sk
, struct sk_buff
*skb
)
1241 __tcp_add_write_queue_tail(sk
, skb
);
1243 /* Queue it, remembering where we must start sending. */
1244 if (sk
->sk_send_head
== NULL
)
1245 sk
->sk_send_head
= skb
;
1248 static inline void __tcp_add_write_queue_head(struct sock
*sk
, struct sk_buff
*skb
)
1250 __skb_queue_head(&sk
->sk_write_queue
, skb
);
1253 /* Insert buff after skb on the write queue of sk. */
1254 static inline void tcp_insert_write_queue_after(struct sk_buff
*skb
,
1255 struct sk_buff
*buff
,
1258 __skb_append(skb
, buff
, &sk
->sk_write_queue
);
1261 /* Insert skb between prev and next on the write queue of sk. */
1262 static inline void tcp_insert_write_queue_before(struct sk_buff
*new,
1263 struct sk_buff
*skb
,
1266 __skb_insert(new, skb
->prev
, skb
, &sk
->sk_write_queue
);
1268 if (sk
->sk_send_head
== skb
)
1269 sk
->sk_send_head
= new;
1272 static inline void tcp_unlink_write_queue(struct sk_buff
*skb
, struct sock
*sk
)
1274 __skb_unlink(skb
, &sk
->sk_write_queue
);
1277 static inline int tcp_skb_is_last(const struct sock
*sk
,
1278 const struct sk_buff
*skb
)
1280 return skb
->next
== (struct sk_buff
*)&sk
->sk_write_queue
;
1283 static inline int tcp_write_queue_empty(struct sock
*sk
)
1285 return skb_queue_empty(&sk
->sk_write_queue
);
1289 enum tcp_seq_states
{
1290 TCP_SEQ_STATE_LISTENING
,
1291 TCP_SEQ_STATE_OPENREQ
,
1292 TCP_SEQ_STATE_ESTABLISHED
,
1293 TCP_SEQ_STATE_TIME_WAIT
,
1296 struct tcp_seq_afinfo
{
1297 struct module
*owner
;
1300 int (*seq_show
) (struct seq_file
*m
, void *v
);
1301 struct file_operations
*seq_fops
;
1304 struct tcp_iter_state
{
1306 enum tcp_seq_states state
;
1307 struct sock
*syn_wait_sk
;
1308 int bucket
, sbucket
, num
, uid
;
1309 struct seq_operations seq_ops
;
1312 extern int tcp_proc_register(struct tcp_seq_afinfo
*afinfo
);
1313 extern void tcp_proc_unregister(struct tcp_seq_afinfo
*afinfo
);
1315 extern struct request_sock_ops tcp_request_sock_ops
;
1317 extern int tcp_v4_destroy_sock(struct sock
*sk
);
1319 extern int tcp_v4_gso_send_check(struct sk_buff
*skb
);
1320 extern struct sk_buff
*tcp_tso_segment(struct sk_buff
*skb
, int features
);
1322 #ifdef CONFIG_PROC_FS
1323 extern int tcp4_proc_init(void);
1324 extern void tcp4_proc_exit(void);
1327 /* TCP af-specific functions */
1328 struct tcp_sock_af_ops
{
1329 #ifdef CONFIG_TCP_MD5SIG
1330 struct tcp_md5sig_key
*(*md5_lookup
) (struct sock
*sk
,
1331 struct sock
*addr_sk
);
1332 int (*calc_md5_hash
) (char *location
,
1333 struct tcp_md5sig_key
*md5
,
1335 struct dst_entry
*dst
,
1336 struct request_sock
*req
,
1338 int protocol
, int len
);
1339 int (*md5_add
) (struct sock
*sk
,
1340 struct sock
*addr_sk
,
1343 int (*md5_parse
) (struct sock
*sk
,
1344 char __user
*optval
,
1349 struct tcp_request_sock_ops
{
1350 #ifdef CONFIG_TCP_MD5SIG
1351 struct tcp_md5sig_key
*(*md5_lookup
) (struct sock
*sk
,
1352 struct request_sock
*req
);
1356 extern void tcp_v4_init(struct net_proto_family
*ops
);
1357 extern void tcp_init(void);