-
Notifications
You must be signed in to change notification settings - Fork 5
/
Copy pathtcp.cpp
1683 lines (1474 loc) · 47.1 KB
/
tcp.cpp
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
#include "arduino_app.h"
#include "mbed.h"
#include "TextLCD.h"
#include <cstring>
#include "tcp.h"
#include "ip.h"
#include "protohdr.h"
#include "util.h"
#include "netconf.h"
#include "errnolist.h"
#define MIN(x,y) ((x)<(y)?(x):(y))
#define MOD(x,y) ((x) % (y))
#define SEQ2IDX_SEND(seq, tcb) MOD((seq)-((tcb)->iss+1), (tcb)->send_buf_size)
#define SEQ2IDX_RECV(seq, tcb) MOD((seq)-((tcb)->irs+1), (tcb)->recv_buf_size)
//#define SEM_DEBUG
#ifdef SEM_DEBUG
#define SEMINFO(s) LOG(s)
#else
#define SEMINFO(s) ;
#endif
using namespace std;
struct tcp_timer_t;
struct tcp_arrival{
tcp_arrival *next;
uint32_t start_seq;
uint32_t end_seq;
~tcp_arrival(){
if(this->next!=NULL) delete this->next;
}
};
struct tcp_ctrlblock{
uint32_t send_unack_seq; //未確認のシーケンス番号で、一番若いもの
uint32_t send_next_seq; //次のデータ転送で使用できるシーケンス番号
uint16_t send_window; //送信ウィンドウサイズ
uint32_t send_wl1; //直近のウィンドウ更新に使用されたセグメントのシーケンス番号
uint32_t send_wl2; //直近のウィンドウ更新に使用されたセグメントの確認番号
uint32_t send_buf_used_len; //送信バッファに入っているデータのバイト数
uint32_t send_buf_size;
bool send_persisttim_enabled; //持続タイマが起動中か
uint32_t iss; //初期送信シーケンス番号
char *send_buf;
bool send_waiting;
uint32_t recv_next_seq; //次のデータ転送で使用できるシーケンス番号
uint16_t recv_window; //受信ウィンドウサイズ
uint32_t recv_buf_size; //受信バッファサイズ
uint32_t recv_ack_counter; //ACKを送るごとに1づつカウントアップしていく
uint32_t recv_fin_seq; //FINを受信後にセットされる、FINのシーケンス番号
uint32_t irs; //初期受信シーケンス番号
char *recv_buf;
bool recv_waiting;
tcp_arrival *arrival_list;
int myfin_state;
#define FIN_NOTREQUESTED 0
#define FIN_REQUESTED 1
#define FIN_SENT 2
#define FIN_ACKED 3
uint32_t myfin_seq; //自身が送信したFINのシーケンス番号（ACKが来たか確かめる用に覚えとく）
int state;
uint16_t rtt;
uint16_t mss; //相手との交渉で決まった値
int opentype;
#define ACTIVE 0
#define PASSIVE 1
int errno;
bool establish_waiting;
bool accept_waiting;
tcp_ctrlblock **tcbqueue; //tcp_ctrlblock*の配列
int backlog; //ソケットキューのサイズ
int tcbqueue_head; //先頭のインデックス
int tcbqueue_len; //格納されている要素数
bool is_userclosed; //close()が呼ばれたか。trueのときCLOSE状態に遷移したらソケット解放を行う
ID ownertsk;
transport_addr addr;
};
#define TCP_STATE_CLOSED 0
#define TCP_STATE_LISTEN 1
#define TCP_STATE_SYN_RCVD 2
#define TCP_STATE_SYN_SENT 3
#define TCP_STATE_ESTABLISHED 4
#define TCP_STATE_FIN_WAIT_1 5
#define TCP_STATE_FIN_WAIT_2 6
#define TCP_STATE_CLOSING 7
#define TCP_STATE_TIME_WAIT 8
#define TCP_STATE_CLOSE_WAIT 9
#define TCP_STATE_LAST_ACK 10
#define TCP_OPT_END_OF_LIST 0
#define TCP_OPT_NOP 1
#define TCP_OPT_MSS 2
#define TCP_OPT_WIN_SCALE 3
#define TCP_OPT_S_ACK_PERM 4
#define TCP_OPT_S_ACK 5
#define TCP_OPT_TIMESTAMP 6
struct tcp_timer_option{
union{
struct{
uint32_t start_seq;
uint32_t end_seq;
uint8_t flags;
bool has_mss;
bool is_zerownd_probe;
transport_addr addr; //send_ctrlsegで送った場合にこちらが優先される（tcbにアドレス未登録の場合があるから）
} resend;
struct{
uint32_t seq;
} delayack;
} option;
#define resend_start_seq option.resend.start_seq
#define resend_end_seq option.resend.end_seq
#define resend_flags option.resend.flags
#define resend_has_mss option.resend.has_mss
#define resend_is_zerownd_probe option.resend.is_zerownd_probe
#define resend_addr option.resend.addr
#define delayack_seq option.delayack.seq
};
struct tcp_timer_t{
tcp_timer_t *next; //連結リストにして、時間切れになる順につなぐ
int type;
#define TCP_TIMER_REMOVED 0 //削除済みの印
#define TCP_TIMER_TYPE_FINACK 1
#define TCP_TIMER_TYPE_RESEND 2
#define TCP_TIMER_TYPE_TIMEWAIT 3
#define TCP_TIMER_TYPE_DELAYACK 4
uint32_t remaining; //前に繋がれている要素の秒数の累計＋remainingで発動
uint32_t msec; //タイマの設定時間（ミリ秒, TCP_TIMER_UNITの倍数）
tcp_ctrlblock *tcb;
tcp_timer_option *option;
};
struct tcb_list{
tcb_list *next;
tcp_ctrlblock *tcb;
};
tcp_timer_t *tcptimer = NULL;
tcb_list *tcblist = NULL;
static void tcp_timer_add(tcp_ctrlblock *tcb, uint32_t sec, int type, tcp_timer_option *opt);
static void tcp_timer_remove_all(tcp_ctrlblock *tcb);
static bool between_le_lt(uint32_t a, uint32_t b, uint32_t c);
static bool between_lt_le(uint32_t a, uint32_t b, uint32_t c);
static bool between_le_le(uint32_t a, uint32_t b, uint32_t c);
static bool between_lt_lt(uint32_t a, uint32_t b, uint32_t c);
tcp_ctrlblock *tcb_new();
static void tcb_alloc_queue(tcp_ctrlblock *tcb, int backlog);
static void tcb_alloc_buf(tcp_ctrlblock *tcb);
static void tcb_reset(tcp_ctrlblock *tcb);
static void tcblist_add(tcp_ctrlblock *tcb);
static void tcblist_add_lock(tcp_ctrlblock *tcb);
static void tcblist_remove(tcp_ctrlblock *tcb);
static void tcblist_remove_lock(tcp_ctrlblock *tcb);
static void tcp_abort(tcp_ctrlblock *tcb);
uint16_t tcp_get_unusedport();
static uint16_t tcp_checksum_recv(ip_hdr *iphdr, tcp_hdr *thdr);
static uint16_t tcp_checksum_send(hdrstack *seg, uint8_t ip_src[], uint8_t ip_dst[]);
static uint32_t tcp_geninitseq();
static hdrstack *make_tcpopt(bool contain_mss, uint16_t mss);
static uint16_t get_tcpopt_mss(tcp_hdr *thdr);
static void tcp_send_ctrlseg(uint32_t seq, uint32_t ack, uint16_t win, uint8_t flags, hdrstack *opt,
uint8_t to_addr[], uint16_t to_port, uint16_t my_port, bool use_resend, tcp_ctrlblock *tcb);
static hdrstack *sendbuf_to_hdrstack(tcp_ctrlblock *tcb, uint32_t from_index, uint32_t len);
static void tcp_send_from_buf(tcp_ctrlblock *tcb);
static bool tcp_resend_from_buf(tcp_ctrlblock *tcb, tcp_timer_option *opt);
void tcp_process(ether_flame *flm, ip_hdr *iphdr, tcp_hdr *thdr);
static void tcp_process_closed(ether_flame *flm, ip_hdr *iphdr, tcp_hdr *thdr, uint16_t payload_len);
static void tcp_process_listen(ether_flame *flm, ip_hdr *iphdr, tcp_hdr *thdr, uint16_t payload_len, tcp_ctrlblock *tcb);
static void tcp_process_synsent(ether_flame *flm, ip_hdr *iphdr, tcp_hdr *thdr, uint16_t payload_len, tcp_ctrlblock *tcb);
static void tcp_process_otherwise(ether_flame *flm, ip_hdr *iphdr, tcp_hdr *thdr, uint16_t payload_len, tcp_ctrlblock *tcb);
static void tcp_write_to_recvbuf(tcp_ctrlblock *tcb, char *data, uint32_t start_seq, uint32_t end_seq);
static int tcp_write_to_sendbuf(tcp_ctrlblock *tcb, const char *data, uint32_t len, TMO timeout);
static int tcp_read_from_recvbuf(tcp_ctrlblock *tcb, char *data, uint32_t len, TMO timeout);
int tcp_connect(tcp_ctrlblock *tcb, TMO timeout);
int tcp_listen(tcp_ctrlblock *tcb, int backlog);
tcp_ctrlblock *tcp_accept(tcp_ctrlblock *tcb, uint8_t client_addr[], uint16_t *client_port, TMO timeout);
int tcp_send(tcp_ctrlblock *tcb, const char *msg, uint32_t len, TMO timeout);
int tcp_receive(tcp_ctrlblock *tcb, char *buf, uint32_t len, TMO timeout);
int tcp_close(tcp_ctrlblock *tcb);
void start_tcp(){
act_tsk(TCP_SEND_TASK);
sta_cyc(TCP_SEND_CYC);
act_tsk(TCP_TIMER_TASK);
sta_cyc(TCP_TIMER_CYC);
}
static void tcp_timer_add(tcp_ctrlblock *tcb, uint32_t sec, int type, tcp_timer_option *opt){
//already locked.
tcp_timer_t *tim = new tcp_timer_t;
tim->type = type;
tim->tcb = tcb;
tim->option = opt;
tim->msec = sec;
tcp_timer_t **pp = &tcptimer;
while(*pp != NULL){
if(sec > (*pp)->remaining){
sec -= (*pp)->remaining;
pp = &((*pp)->next);
}else{
break;
}
}
tim->next = *pp;
*pp = tim;
tim->remaining = sec;
pp = &tim->next;
if(*pp!=NULL){
(*pp)->remaining -= sec;
}
return;
}
static void tcp_timer_remove_all(tcp_ctrlblock *tcb){
tcp_timer_t *ptr = tcptimer;
while(ptr!=NULL){
if(ptr->tcb == tcb)
ptr->type = TCP_TIMER_REMOVED;
ptr = ptr->next;
}
return;
}
static bool between_le_lt(uint32_t a, uint32_t b, uint32_t c){
//mod 2^32で計算
if(a < c)
return (a<=b) && (b<c);
else if(a > c)
return (a<=b) || (b<c);
else
return false;
}
static bool between_lt_le(uint32_t a, uint32_t b, uint32_t c){
//mod 2^32で計算
if(a < c)
return (a<b) && (b<=c);
else if(a > c)
return (a<b) || (b<=c);
else
return false;
}
static bool between_le_le(uint32_t a, uint32_t b, uint32_t c){
//mod 2^32で計算
if(a < c)
return (a<=b) && (b<=c);
else if(a > c)
return (a<=b) || (b<=c);
else
return a==b;
}
static bool between_lt_lt(uint32_t a, uint32_t b, uint32_t c){
//mod 2^32で計算
if(a < c)
return (a<b) && (b<c);
else if(a > c)
return (a<b) || (b<c);
else
return false;
}
static void tcp_abort(tcp_ctrlblock *tcb){
//already locked.
switch(tcb->state){
case TCP_STATE_SYN_RCVD:
case TCP_STATE_ESTABLISHED:
case TCP_STATE_FIN_WAIT_1:
case TCP_STATE_FIN_WAIT_2:
case TCP_STATE_CLOSE_WAIT:
tcp_send_ctrlseg(tcb->send_next_seq, 0, 0, TH_RST, NULL,
tcb->addr.partner_addr, tcb->addr.partner_port, tcb->addr.my_port, false, NULL);
}
tcb_reset(tcb);
}
void tcb_init(tcp_ctrlblock *tcb){
ID owner = tcb->ownertsk;
bool rw = tcb->recv_waiting, sw = tcb->send_waiting,
aw = tcb->accept_waiting, ew = tcb->establish_waiting;
int errno = tcb->errno;
memset(tcb, 0, sizeof(tcp_ctrlblock));
//以下は、リセット後に使用される かつ 残っていても影響が無いため復元
tcb->ownertsk = owner;
tcb->recv_waiting = rw; tcb->send_waiting = sw;
tcb->accept_waiting = aw; tcb->establish_waiting = ew;
tcb->errno = errno;
tcb->is_userclosed = false;
tcb->send_persisttim_enabled = false;
tcb->state = TCP_STATE_CLOSED;
tcb->rtt = TCP_RTT_INIT;
tcb->myfin_state = FIN_NOTREQUESTED;
//まだメモリは確保していないけど、あらかじめサイズを相手方に通知しないといけないのでサイズだけ代入しておく
tcb->recv_buf_size = STREAM_RECV_BUF;
tcb->send_buf_size = STREAM_SEND_BUF;
}
static void tcb_reset(tcp_ctrlblock *tcb){
if(tcb->backlog>0){
int idx = tcb->tcbqueue_head;
while(tcb->tcbqueue_len>0){
tcb->tcbqueue[idx]->is_userclosed = true;
tcp_abort(tcb->tcbqueue[idx]);
idx = (idx+1) % tcb->backlog;
tcb->tcbqueue_len--;
}
delete [] tcb->tcbqueue;
}
if(tcb->recv_buf!=NULL){
delete [] tcb->recv_buf;
}
if(tcb->send_buf!=NULL){
delete [] tcb->send_buf;
}
if(tcb->arrival_list != NULL){
delete tcb->arrival_list;
}
tcp_timer_remove_all(tcb);
tcblist_remove(tcb);
if(tcb->is_userclosed){
delete tcb;
}else{
tcb_init(tcb);
}
return;
}
//メモリ節約のため、接続を確立するまでバッファの領域確保は行わない
//確保は、後からtcp_allocbuf()で行う
tcp_ctrlblock *tcb_new(){
tcp_ctrlblock *tcb = new tcp_ctrlblock;
tcb_init(tcb);
return tcb;
}
void tcb_setaddr_and_owner(tcp_ctrlblock *tcb, transport_addr *addr, ID owner){
tcb->addr = *addr;
tcb->ownertsk = owner;
}
transport_addr *tcb_getaddr(tcp_ctrlblock *tcb){
return &(tcb->addr);
}
ID tcb_getowner(tcp_ctrlblock *tcb){
return tcb->ownertsk;
}
static void tcb_alloc_queue(tcp_ctrlblock *tcb, int backlog){
if(tcb->tcbqueue != NULL){
delete [] tcb->tcbqueue;
tcb->tcbqueue = NULL;
}
if(backlog > 0){
tcb->backlog = backlog;
tcb->tcbqueue_head = 0;
tcb->tcbqueue_len = 0;
tcb->tcbqueue = new tcp_ctrlblock*[backlog];
}else{
tcb->backlog = 0;
tcb->tcbqueue_head = 0;
tcb->tcbqueue_len = 0;
tcb->tcbqueue = NULL;
}
return;
}
//ESTABLISHEDになってはじめてバッファを確保する
static void tcb_alloc_buf(tcp_ctrlblock *tcb){
//2MSL待ちが長いと、メモリ不足で以下のnewで例外発生の可能性がある（今のところ対策はしていない）
tcb->recv_buf = new char[tcb->recv_buf_size];
tcb->send_buf = new char[tcb->send_buf_size];
tcb->send_wl1 = 0;
tcb->send_wl2 = 0;
tcb->recv_window = tcb->recv_buf_size;
return;
}
//初期シーケンス番号を生成する
static uint32_t tcp_geninitseq(){
SYSTIM systim;
get_tim(&systim);
return systim + 64000;
}
static uint16_t tcp_checksum_recv(ip_hdr *iphdr, tcp_hdr *thdr){
tcp_pseudo_hdr pseudo;
memcpy(pseudo.tp_src, iphdr->ip_src, IP_ADDR_LEN);
memcpy(pseudo.tp_dst, iphdr->ip_dst, IP_ADDR_LEN);
pseudo.tp_type = 6;
pseudo.tp_void = 0;
pseudo.tp_len = hton16(ntoh16(iphdr->ip_len) - iphdr->ip_hl*4); //TCPヘッダ+TCPペイロードの長さ
return checksum2((uint16_t*)(&pseudo), (uint16_t*)thdr, sizeof(tcp_pseudo_hdr), ntoh16(iphdr->ip_len) - iphdr->ip_hl*4);
}
static uint16_t tcp_checksum_send(hdrstack *seg, uint8_t ip_src[], uint8_t ip_dst[]){
int segsize = hdrstack_totallen(seg);
tcp_pseudo_hdr pseudo;
memcpy(pseudo.tp_src, ip_src, IP_ADDR_LEN);
memcpy(pseudo.tp_dst, ip_dst, IP_ADDR_LEN);
pseudo.tp_type = 6;
pseudo.tp_void = 0;
pseudo.tp_len = hton16(segsize); //TCPヘッダ+TCPペイロードの長さ
hdrstack *pseudo_hdr = new hdrstack(false);
pseudo_hdr->buf = (char*)&pseudo;
pseudo_hdr->size = sizeof(tcp_pseudo_hdr);
pseudo_hdr->next = seg;
uint16_t result = checksum_hdrstack(pseudo_hdr);
pseudo_hdr->next = NULL;
delete pseudo_hdr;
return result;
}
//他のオプションは順次対応
static hdrstack *make_tcpopt(bool contain_mss, uint16_t mss){
int optlen = 0;
if(contain_mss) optlen += 4;
hdrstack *opt = new hdrstack(true);
opt->size = optlen;
opt->next = NULL;
opt->buf = new char[opt->size];
char *opt_next = opt->buf;
if(contain_mss){
opt_next[0] = TCP_OPT_MSS;
opt_next[1] = 4;
*((uint16_t*)(opt_next+2)) = hton16(mss);
opt_next += 4;
}
return opt;
}
//見つからければデフォルト値を返す
static uint16_t get_tcpopt_mss(tcp_hdr *thdr){
uint8_t *optptr = ((uint8_t*)(thdr+1));
uint8_t *datastart = ((uint8_t*)thdr) + thdr->th_off*4;
while(optptr < datastart){
switch(*optptr){
case TCP_OPT_END_OF_LIST:
return -1;
case TCP_OPT_NOP:
optptr++;
break;
case TCP_OPT_MSS:
return ntoh16(*((uint16_t*)(optptr+2)));
default:
optptr += (*(optptr+1))-2;
break;
}
}
return 536;
}
//制御用のセグメント（ペイロードなし）を送信
static void tcp_send_ctrlseg(uint32_t seq, uint32_t ack, uint16_t win, uint8_t flags, hdrstack *opt,
uint8_t to_addr[], uint16_t to_port, uint16_t my_port, bool use_resend, tcp_ctrlblock *tcb){
ip_hdr iphdr;
memcpy(iphdr.ip_src, IPADDR, IP_ADDR_LEN);
memcpy(iphdr.ip_dst, to_addr, IP_ADDR_LEN);
tcp_hdr *thdr = new tcp_hdr;
thdr->th_sport = hton16(my_port);
thdr->th_dport = hton16(to_port);
thdr->th_seq = hton32(seq);
thdr->th_ack = hton32(ack);
thdr->th_flags = flags;
thdr->th_x2 = 0;
thdr->th_win = hton16(win);
thdr->th_sum = 0;
thdr->th_urp = 0;
hdrstack *tcpseg = new hdrstack(true);
tcpseg->size = sizeof(tcp_hdr);
tcpseg->buf = (char*)thdr;
tcpseg->next = opt;
thdr->th_off = (sizeof(tcp_hdr) + opt->size) / 4;
thdr->th_sum = tcp_checksum_send(tcpseg, IPADDR, to_addr);
tcp_timer_option *timer_opt;
if(use_resend){
timer_opt = new tcp_timer_option;
timer_opt->resend_start_seq = seq;
timer_opt->resend_end_seq = seq;
timer_opt->resend_flags = flags;
timer_opt->resend_has_mss = !(opt==NULL);
timer_opt->resend_is_zerownd_probe = false;
timer_opt->resend_addr.my_port = my_port;
timer_opt->resend_addr.partner_port = to_port;
memcpy(timer_opt->resend_addr.partner_addr, to_addr, IP_ADDR_LEN);
}
ip_send(tcpseg, to_addr, IPTYPE_TCP);
if(use_resend)
tcp_timer_add(tcb, tcb->rtt*TCP_TIMER_UNIT, TCP_TIMER_TYPE_RESEND, timer_opt);
}
static void tcp_process_closed(ether_flame *flm, ip_hdr *iphdr, tcp_hdr *thdr, uint16_t payload_len){
if(!(thdr->th_flags & TH_RST)){
if(thdr->th_flags & TH_ACK){
tcp_send_ctrlseg(0, ntoh32(thdr->th_seq)+payload_len, 0, TH_ACK|TH_RST, NULL, iphdr->ip_src, ntoh16(thdr->th_sport), ntoh16(thdr->th_dport), false, NULL);
}else
tcp_send_ctrlseg(ntoh32(thdr->th_ack), 0, 0, TH_RST, NULL, iphdr->ip_src, ntoh16(thdr->th_sport), ntoh16(thdr->th_dport), false, NULL);
}
delete flm;
}
static void tcp_process_listen(ether_flame *flm, ip_hdr *iphdr, tcp_hdr *thdr, uint16_t payload_len, tcp_ctrlblock *tcb){
if(thdr->th_flags & TH_RST){
goto exit;
}
if(thdr->th_flags & TH_ACK){
tcp_send_ctrlseg(ntoh32(thdr->th_ack), 0, 0, TH_RST, NULL, iphdr->ip_src, ntoh16(thdr->th_sport), ntoh16(thdr->th_dport), false, NULL);
goto exit;
}
if(thdr->th_flags & TH_SYN){
//キューに入れる
tcp_ctrlblock *newtcb;
if(tcb->backlog > tcb->tcbqueue_len){
//空き
newtcb = tcb_new();
tcb->tcbqueue[(tcb->tcbqueue_head+tcb->tcbqueue_len)%tcb->backlog] = newtcb;
tcb_setaddr_and_owner(newtcb, &(tcb->addr), tcb->ownertsk);
tcb->tcbqueue_len++;
}else{
if(tcb->backlog>0) LOG("Error: tcbqueue is full.");
goto exit;
}
memcpy(newtcb->addr.partner_addr, iphdr->ip_src, IP_ADDR_LEN);
newtcb->state = TCP_STATE_LISTEN;
newtcb->addr.partner_port = ntoh16(thdr->th_sport);
newtcb->recv_next_seq = ntoh32(thdr->th_seq)+1;
newtcb->irs = ntoh32(thdr->th_seq);
newtcb->send_window = MIN(ntoh16(thdr->th_win), tcb->send_buf_size);
newtcb->send_wl1 = ntoh32(thdr->th_seq);
newtcb->send_wl2 = ntoh32(thdr->th_ack);
newtcb->mss = MIN(get_tcpopt_mss(thdr), MSS);
tcblist_add(newtcb);
if(tcb->accept_waiting) wup_tsk(tcb->ownertsk);
}
exit:
delete flm;
return;
}
static void tcp_process_synsent(ether_flame *flm, ip_hdr *iphdr, tcp_hdr *thdr, uint16_t payload_len, tcp_ctrlblock *tcb){
if(thdr->th_flags & TH_ACK){
if(ntoh32(thdr->th_ack) != tcb->iss+1){
if(!(thdr->th_flags & TH_RST)){
tcp_send_ctrlseg(ntoh32(thdr->th_ack), 0, 0, TH_RST, NULL, iphdr->ip_src, ntoh16(thdr->th_sport), ntoh16(thdr->th_dport), false, NULL);
}
goto exit;
}else{
tcb->send_unack_seq++;
}
}
if(thdr->th_flags & TH_RST){
if(between_le_le(tcb->send_unack_seq, ntoh32(thdr->th_ack), tcb->send_next_seq)){
tcb_reset(tcb);
if(tcb->establish_waiting) wup_tsk(tcb->ownertsk);
}
goto exit;
}
if(thdr->th_flags & TH_SYN){
tcb->recv_next_seq = ntoh32(thdr->th_seq)+1;
tcb->irs = ntoh32(thdr->th_seq);
if(thdr->th_flags & TH_ACK)
tcb->send_unack_seq = ntoh32(thdr->th_ack);
if(tcb->send_unack_seq == tcb->iss){
tcb->state = TCP_STATE_SYN_RCVD;
tcp_send_ctrlseg(tcb->iss, tcb->recv_next_seq, 0, TH_SYN|TH_ACK, make_tcpopt(true, MSS), iphdr->ip_src, ntoh16(thdr->th_sport), ntoh16(thdr->th_dport), true, tcb);
tcb->recv_ack_counter++;
}else{
tcb->send_window = MIN(ntoh16(thdr->th_win), tcb->send_buf_size);
tcb->send_wl1 = ntoh32(thdr->th_seq);
tcb->send_wl2 = ntoh32(thdr->th_ack);
tcb->mss = MIN(get_tcpopt_mss(thdr), MSS);
tcb_alloc_buf(tcb);
tcb->state = TCP_STATE_ESTABLISHED;
tcp_send_ctrlseg(tcb->send_next_seq, tcb->recv_next_seq, tcb->recv_window, TH_ACK, NULL, iphdr->ip_src, ntoh16(thdr->th_sport), ntoh16(thdr->th_dport), false, NULL);
tcb->recv_ack_counter++;
if(tcb->establish_waiting) wup_tsk(tcb->ownertsk);
}
}
exit:
delete flm;
return;
}
static void tcp_arrival_add(tcp_ctrlblock *tcb, uint32_t start_seq, uint32_t end_seq){
tcp_arrival *newarrival = new tcp_arrival;
newarrival->start_seq = start_seq;
newarrival->end_seq = end_seq;
tcp_arrival **pp = &(tcb->arrival_list);
while((*pp)!=NULL){
bool is_remove = false;
if(between_le_le(tcb->recv_next_seq, (*pp)->start_seq-1, newarrival->end_seq)){
//末尾が重なっているor連続している
newarrival->end_seq = (*pp)->end_seq;
is_remove = true;
}
if(between_le_le(tcb->recv_next_seq, newarrival->start_seq, (*pp)->end_seq+1)){
//先頭が重なっているor連続している
newarrival->start_seq = (*pp)->start_seq;
is_remove = true;
}
if(is_remove){
tcp_arrival *temp = *pp;
*pp = (*pp)->next;
delete temp;
}
}
newarrival->next = tcb->arrival_list;
tcb->arrival_list = newarrival;
}
//アプリケーションに引き渡せる連続したデータのバイト数を返す
static uint32_t tcp_arrival_handover(tcp_ctrlblock *tcb){
tcp_arrival **pp = &(tcb->arrival_list);
while((*pp)!=NULL){
if(tcb->recv_next_seq == (*pp)->start_seq){
uint32_t len = (*pp)->end_seq - (*pp)->start_seq + 1;
tcb->recv_next_seq += len;
tcb->recv_window -= len;
//削除
tcp_arrival *temp = *pp;
*pp = (*pp)->next;
delete temp;
return len;
}
}
LOG("---");
return 0;
}
static void tcp_write_to_recvbuf(tcp_ctrlblock *tcb, char *data, uint32_t len, uint32_t start_seq){
uint32_t start_index = SEQ2IDX_RECV(start_seq, tcb);
uint32_t end_seq;
uint32_t end_index;
if(between_le_lt(start_seq, start_seq+len-1, tcb->recv_next_seq+tcb->recv_window))
end_seq = start_seq+len-1;
else
end_seq = tcb->recv_next_seq+tcb->recv_window-1;
end_index = SEQ2IDX_RECV(end_seq, tcb);
uint32_t end_next_index = MOD(end_index+1, tcb->recv_buf_size);
for(uint32_t i=start_index; i!=end_next_index; i=MOD(i+1, tcb->recv_buf_size)){
tcb->recv_buf[i] = *data++;
}
tcp_arrival_add(tcb, start_seq, end_seq);
if(tcb->recv_next_seq == start_seq){
tcp_arrival_handover(tcb);
if(tcb->recv_waiting) wup_tsk(tcb->ownertsk);
}
}
//fromインデックスからlenバイトの区間をhdrstackとして返す（配列が循環していることを考慮して）
static hdrstack *sendbuf_to_hdrstack(tcp_ctrlblock *tcb, uint32_t from_index, uint32_t len){
hdrstack *payload1 = new hdrstack(false);
hdrstack *payload2 = NULL;
if(tcb->send_buf_size - from_index >= len){
//折り返さない
payload1->size = len;
payload1->next = NULL;
payload1->buf = &(tcb->send_buf[from_index]);
return payload1;
}else{
//折り返す
payload1->size = tcb->send_buf_size-from_index;
payload1->buf = &(tcb->send_buf[from_index]);
payload2 = new hdrstack(false);
payload1->next = payload2;
payload2->size = len - payload1->size;
payload2->next = NULL;
payload2->buf = tcb->send_buf;
return payload1;
}
}
static void tcp_send_from_buf(tcp_ctrlblock *tcb){
bool is_zerownd_probe = false;
static tcp_hdr tcphdr_template;
tcphdr_template.th_dport = hton16(tcb->addr.partner_port);
tcphdr_template.th_flags = TH_ACK;
tcphdr_template.th_off = sizeof(tcp_hdr)/4;
tcphdr_template.th_sport = hton16(tcb->addr.my_port);
tcphdr_template.th_sum = 0;
tcphdr_template.th_urp = 0;
tcphdr_template.th_x2 = 0;
if(tcb->send_persisttim_enabled == false && tcb->send_window == 0){
if(between_le_lt(tcb->send_unack_seq, tcb->send_next_seq, tcb->send_unack_seq+tcb->send_buf_used_len)){
//1byte以上の送信可能なデータが存在
is_zerownd_probe = true;
tcb->send_persisttim_enabled = true;
}
}
while(is_zerownd_probe ||
(tcb->send_buf_used_len>0 &&
!between_le_lt(tcb->send_unack_seq,
tcb->send_unack_seq+tcb->send_buf_used_len-1, tcb->send_next_seq))){
int payload_len_all;
if(between_le_lt(tcb->send_next_seq, tcb->send_unack_seq+tcb->send_buf_used_len, tcb->send_next_seq+tcb->send_window))
payload_len_all = tcb->send_unack_seq+tcb->send_buf_used_len - tcb->send_next_seq;
else
payload_len_all = tcb->send_next_seq+tcb->send_window - tcb->send_next_seq;
int payload_len = MIN(payload_len_all, tcb->mss);
if(is_zerownd_probe) payload_len = 1;
if(payload_len == 0) break;
hdrstack *payload = sendbuf_to_hdrstack(tcb, SEQ2IDX_SEND(tcb->send_next_seq, tcb), payload_len);
tcp_timer_option *opt;
opt = new tcp_timer_option;
opt->option.resend.start_seq = tcb->send_next_seq;
opt->option.resend.end_seq = tcb->send_next_seq + payload_len -1;
opt->option.resend.flags = tcphdr_template.th_flags;
opt->option.resend.has_mss = false;
opt->option.resend.is_zerownd_probe = is_zerownd_probe;
hdrstack *tcpseg = new hdrstack(true);
tcpseg->size = sizeof(tcp_hdr);
tcpseg->buf = new char[sizeof(tcp_hdr)];
memcpy(tcpseg->buf, &tcphdr_template, sizeof(tcp_hdr));
tcpseg->next = payload;
tcp_hdr *thdr = (tcp_hdr*)tcpseg->buf;
thdr->th_seq = hton32(tcb->send_next_seq);
thdr->th_ack = hton32(tcb->recv_next_seq);
thdr->th_win = hton16(tcb->recv_window);
thdr->th_sum = tcp_checksum_send(tcpseg, IPADDR, tcb->addr.partner_addr);
if(!is_zerownd_probe){
tcb->send_next_seq += payload_len;
tcb->send_window -= payload_len;
}
ip_send(tcpseg, tcb->addr.partner_addr, IPTYPE_TCP);
tcb->recv_ack_counter++;
tcp_timer_add(tcb, tcb->rtt*TCP_TIMER_UNIT, TCP_TIMER_TYPE_RESEND, opt);
is_zerownd_probe = false; //1回だけ
//送信タスク（これ）が長時間実行されることを防ぐために、オーバランハンドラで制限をかけたほうが良さそう
}
if(tcb->send_window > 0 && tcb->myfin_state == FIN_REQUESTED){
//送信ウィンドウが0でなく、かつここまで降りてきてFIN送信要求が出ているということは送信すべきものがもう無いのでFINを送って良い
tcb->myfin_state = FIN_SENT;
tcb->myfin_seq = tcb->send_next_seq;
tcb->send_next_seq++;
tcp_send_ctrlseg(tcb->myfin_seq, tcb->recv_next_seq, tcb->recv_window, TH_FIN|TH_ACK, NULL, tcb->addr.partner_addr, tcb->addr.partner_port, tcb->addr.my_port, true, tcb);
tcb->recv_ack_counter++;
if(tcb->state == TCP_STATE_CLOSE_WAIT)
tcb->state = TCP_STATE_LAST_ACK;
}
return;
}
static bool tcp_resend_from_buf(tcp_ctrlblock *tcb, tcp_timer_option *opt){
if(!between_le_lt(tcb->send_unack_seq, opt->resend_end_seq, tcb->send_next_seq+tcb->send_window)){
return false; //送信可能なものはない
}
//send_ctrlsegで送ったものか（データ無し）
if(opt->resend_start_seq == opt->resend_end_seq){
tcp_send_ctrlseg(opt->resend_start_seq, tcb->recv_next_seq, tcb->recv_window, opt->resend_flags,
opt->resend_has_mss?make_tcpopt(true, MSS):NULL, opt->resend_addr.partner_addr,
opt->resend_addr.partner_port, opt->resend_addr.my_port, false, NULL);
if(opt->resend_flags & TH_ACK)
tcb->recv_ack_counter++;
return true;
}
int payload_len;
if(opt->resend_is_zerownd_probe)
payload_len = 1;
else
payload_len = opt->resend_end_seq - opt->resend_start_seq + 1;
hdrstack *payload = sendbuf_to_hdrstack(tcb, SEQ2IDX_SEND(opt->resend_start_seq, tcb), payload_len);
hdrstack *tcpseg = new hdrstack(true);
tcpseg->size = sizeof(tcp_hdr);
tcpseg->buf = new char[sizeof(tcp_hdr)];
tcpseg->next = payload;
tcp_hdr *thdr = (tcp_hdr*)tcpseg->buf;
thdr->th_dport = hton16(tcb->addr.partner_port);
thdr->th_flags = TH_ACK;
thdr->th_off = sizeof(tcp_hdr)/4;
thdr->th_sport = hton16(tcb->addr.my_port);
thdr->th_sum = 0;
thdr->th_urp = 0;
thdr->th_x2 = 0;
thdr->th_seq = hton32(opt->resend_start_seq);
thdr->th_ack = hton32(tcb->recv_next_seq);
thdr->th_win = hton16(tcb->recv_window);
thdr->th_sum = tcp_checksum_send(tcpseg, IPADDR, tcb->addr.partner_addr);
ip_send(tcpseg, tcb->addr.partner_addr, IPTYPE_TCP);
tcb->recv_ack_counter++;
return true;
}
static int tcp_write_to_sendbuf(tcp_ctrlblock *tcb, const char *data, uint32_t len, TMO timeout){
//already locked.
tcb->send_waiting = true;
uint32_t remain = len;
while(remain > 0){
if(tcb->send_buf_used_len < tcb->send_buf_size){
tcb->send_buf[SEQ2IDX_SEND(tcb->send_unack_seq+tcb->send_buf_used_len, tcb)] = *data++;
remain--;
tcb->send_buf_used_len++;
}else{
//already locked.
wup_tsk(TCP_SEND_TASK);
mcled_change(COLOR_PINK);
sig_sem(TCP_SEM);
if(tslp_tsk(timeout) == E_TMOUT){
wai_sem(TCP_SEM);
tcb->send_waiting = false;
//ロックされている状態でtcp_sendにreturn
return len-remain;
}
wai_sem(TCP_SEM);
mcled_change(COLOR_GREEN);
switch(tcb->state){
case TCP_STATE_CLOSED:
case TCP_STATE_LISTEN:
case TCP_STATE_SYN_SENT:
case TCP_STATE_SYN_RCVD:
return ECONNNOTEXIST;
case TCP_STATE_FIN_WAIT_1:
case TCP_STATE_FIN_WAIT_2:
case TCP_STATE_CLOSING:
case TCP_STATE_LAST_ACK:
case TCP_STATE_TIME_WAIT:
return ECONNCLOSING;
}
}
}
tcb->send_waiting = false;
return len - remain;
}
static int tcp_read_from_recvbuf(tcp_ctrlblock *tcb, char *data, uint32_t len, TMO timeout){
//already locked.
tcb->recv_waiting = true;
uint32_t remain = len;
uint32_t head_index = SEQ2IDX_RECV(tcb->recv_next_seq-(tcb->recv_buf_size-tcb->recv_window), tcb);
while(true){
if(tcb->recv_window == tcb->recv_buf_size){
//バッファが空
switch(tcb->state){
case TCP_STATE_ESTABLISHED:
case TCP_STATE_FIN_WAIT_1:
case TCP_STATE_FIN_WAIT_2:
break;
default:
//FINを受信していて、かつバッファが空
if(tcb->recv_fin_seq==tcb->recv_next_seq){
if(tcb->recv_buf!=NULL){
delete [] tcb->recv_buf;
tcb->recv_buf = NULL;
}
}
return ECONNCLOSING;
}
}
while(tcb->recv_window != tcb->recv_buf_size && remain > 0){
*data++ = tcb->recv_buf[head_index];
tcb->recv_window++;
remain--;
head_index = MOD(head_index+1, tcb->recv_buf_size);
}
//最低1byteは読む
if(remain == len){
//already locked.
sig_sem(TCP_SEM);
if(tslp_tsk(timeout) == E_TMOUT){
wai_sem(TCP_SEM);
tcb->recv_waiting = false;
//ロック状態でreturn
return ETIMEOUT;
}
wai_sem(TCP_SEM);
switch(tcb->state){
case TCP_STATE_CLOSED:
case TCP_STATE_LISTEN:
case TCP_STATE_SYN_SENT:
case TCP_STATE_SYN_RCVD:
return ECONNNOTEXIST;
case TCP_STATE_CLOSING:
case TCP_STATE_LAST_ACK:
case TCP_STATE_TIME_WAIT:
return ECONNCLOSING;
}
}else{
tcb->recv_waiting = false;
return len - remain;
}
}
}
static void tcp_process_otherwise(ether_flame *flm, ip_hdr *iphdr, tcp_hdr *thdr, uint16_t payload_len, tcp_ctrlblock *tcb){
if(payload_len == 0 && tcb->recv_window == 0){
if(ntoh32(thdr->th_seq) != tcb->recv_next_seq)
goto cantrecv;
}else if(payload_len == 0 && tcb->recv_window > 0){
if(!between_le_lt(tcb->recv_next_seq, ntoh32(thdr->th_seq), tcb->recv_next_seq+tcb->recv_window))
goto cantrecv;
}else if(payload_len > 0 && tcb->recv_window == 0){
goto cantrecv;
}else if(payload_len > 0 && tcb->recv_window > 0){
if(!(between_le_lt(tcb->recv_next_seq, ntoh32(thdr->th_seq), tcb->recv_next_seq+tcb->recv_window) ||
between_le_lt(tcb->recv_next_seq, ntoh32(thdr->th_seq)+payload_len-1, tcb->recv_next_seq+tcb->recv_window)))
goto cantrecv;
}
if(thdr->th_flags & TH_RST){
switch(tcb->state){