forked from sde1000/NanodeUIP
-
Notifications
You must be signed in to change notification settings - Fork 12
/
uip.cpp
1931 lines (1700 loc) · 58 KB
/
uip.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
#define DEBUG_PRINTF(...) /*printf(__VA_ARGS__)*/
/**
* \defgroup uip The uIP TCP/IP stack
* @{
*
* uIP is an implementation of the TCP/IP protocol stack intended for
* small 8-bit and 16-bit microcontrollers.
*
* uIP provides the necessary protocols for Internet communication,
* with a very small code footprint and RAM requirements - the uIP
* code size is on the order of a few kilobytes and RAM usage is on
* the order of a few hundred bytes.
*/
/**
* \file
* The uIP TCP/IP stack code.
* \author Adam Dunkels <[email protected]>
*/
/*
* Copyright (c) 2001-2003, Adam Dunkels.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
* GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* This file is part of the uIP TCP/IP stack.
*
* $Id: uip.c,v 1.65 2006/06/11 21:46:39 adam Exp $
*
*/
/*
* uIP is a small implementation of the IP, UDP and TCP protocols (as
* well as some basic ICMP stuff). The implementation couples the IP,
* UDP, TCP and the application layers very tightly. To keep the size
* of the compiled code down, this code frequently uses the goto
* statement. While it would be possible to break the uip_process()
* function into many smaller functions, this would increase the code
* size because of the overhead of parameter passing and the fact that
* the optimier would not be as efficient.
*
* The principle is that we have a small buffer, called the uip_buf,
* in which the device driver puts an incoming packet. The TCP/IP
* stack parses the headers in the packet, and calls the
* application. If the remote host has sent data to the application,
* this data is present in the uip_buf and the application read the
* data from there. It is up to the application to put this data into
* a byte stream if needed. The application will not be fed with data
* that is out of sequence.
*
* If the application whishes to send data to the peer, it should put
* its data into the uip_buf. The uip_appdata pointer points to the
* first available byte. The TCP/IP stack will calculate the
* checksums, and fill in the necessary header fields and finally send
* the packet back to the peer.
*/
#include "uip.h"
#include "uipopt.h"
#include "uip_arch.h"
#if UIP_CONF_IPV6
#include "uip-neighbor.h"
#endif /* UIP_CONF_IPV6 */
#include <string.h>
/*---------------------------------------------------------------------------*/
/* Variable definitions. */
/* The IP address of this host. If it is defined to be fixed (by
setting UIP_FIXEDADDR to 1 in uipopt.h), the address is set
here. Otherwise, the address */
#if UIP_FIXEDADDR > 0
const uip_ipaddr_t uip_hostaddr =
{UIP_HTONS((UIP_IPADDR0 << 8) | UIP_IPADDR1),
UIP_HTONS((UIP_IPADDR2 << 8) | UIP_IPADDR3)};
const uip_ipaddr_t uip_draddr =
{UIP_HTONS((UIP_DRIPADDR0 << 8) | UIP_DRIPADDR1),
UIP_HTONS((UIP_DRIPADDR2 << 8) | UIP_DRIPADDR3)};
const uip_ipaddr_t uip_netmask =
{UIP_HTONS((UIP_NETMASK0 << 8) | UIP_NETMASK1),
UIP_HTONS((UIP_NETMASK2 << 8) | UIP_NETMASK3)};
#else
uip_ipaddr_t uip_hostaddr, uip_draddr, uip_netmask;
#endif /* UIP_FIXEDADDR */
static const uip_ipaddr_t all_ones_addr =
#if UIP_CONF_IPV6
{0xffff,0xffff,0xffff,0xffff,0xffff,0xffff,0xffff,0xffff};
#else /* UIP_CONF_IPV6 */
{0xffff,0xffff};
#endif /* UIP_CONF_IPV6 */
static const uip_ipaddr_t all_zeroes_addr =
#if UIP_CONF_IPV6
{0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000};
#else /* UIP_CONF_IPV6 */
{0x0000,0x0000};
#endif /* UIP_CONF_IPV6 */
#if UIP_FIXEDETHADDR
const struct uip_eth_addr uip_ethaddr = {{UIP_ETHADDR0,
UIP_ETHADDR1,
UIP_ETHADDR2,
UIP_ETHADDR3,
UIP_ETHADDR4,
UIP_ETHADDR5}};
#else
struct uip_eth_addr uip_ethaddr = {{0,0,0,0,0,0}};
#endif
#ifndef UIP_CONF_EXTERNAL_BUFFER
u8_t uip_buf[UIP_BUFSIZE + 2]; /* The packet buffer that contains
incoming packets. */
#endif /* UIP_CONF_EXTERNAL_BUFFER */
void *uip_appdata; /* The uip_appdata pointer points to
application data. */
void *uip_sappdata; /* The uip_appdata pointer points to
the application data which is to
be sent. */
#if UIP_URGDATA > 0
void *uip_urgdata; /* The uip_urgdata pointer points to
urgent data (out-of-band data), if
present. */
u16_t uip_urglen, uip_surglen;
#endif /* UIP_URGDATA > 0 */
u16_t uip_len, uip_slen;
/* The uip_len is either 8 or 16 bits,
depending on the maximum packet
size. */
u8_t uip_flags; /* The uip_flags variable is used for
communication between the TCP/IP stack
and the application program. */
struct uip_conn *uip_conn; /* uip_conn always points to the current
connection. */
struct uip_conn uip_conns[UIP_CONNS];
/* The uip_conns array holds all TCP
connections. */
u16_t uip_listenports[UIP_LISTENPORTS];
/* The uip_listenports list all currently
listning ports. */
tcp_appcall_fn *uip_listenapps[UIP_LISTENPORTS];
/* Application functions corresponding to
listening ports. */
#if UIP_UDP
struct uip_udp_conn *uip_udp_conn;
struct uip_udp_conn uip_udp_conns[UIP_UDP_CONNS];
#endif /* UIP_UDP */
static u16_t ipid; /* Ths ipid variable is an increasing
number that is used for the IP ID
field. */
void uip_setipid(u16_t id) { ipid = id; }
static u8_t iss[4]; /* The iss variable is used for the TCP
initial sequence number. */
#if UIP_ACTIVE_OPEN
static u16_t lastport; /* Keeps track of the last port used for
a new connection. */
#endif /* UIP_ACTIVE_OPEN */
/* Temporary variables. */
u8_t uip_acc32[4];
static u8_t c, opt;
static u16_t tmp16;
/* Structures and definitions. */
#define TCP_FIN 0x01
#define TCP_SYN 0x02
#define TCP_RST 0x04
#define TCP_PSH 0x08
#define TCP_ACK 0x10
#define TCP_URG 0x20
#define TCP_CTL 0x3f
#define TCP_OPT_END 0 /* End of TCP options list */
#define TCP_OPT_NOOP 1 /* "No-operation" TCP option */
#define TCP_OPT_MSS 2 /* Maximum segment size TCP option */
#define TCP_OPT_MSS_LEN 4 /* Length of TCP MSS option. */
#define ICMP_ECHO_REPLY 0
#define ICMP_ECHO 8
#define ICMP6_ECHO_REPLY 129
#define ICMP6_ECHO 128
#define ICMP6_NEIGHBOR_SOLICITATION 135
#define ICMP6_NEIGHBOR_ADVERTISEMENT 136
#define ICMP6_FLAG_S (1 << 6)
#define ICMP6_OPTION_SOURCE_LINK_ADDRESS 1
#define ICMP6_OPTION_TARGET_LINK_ADDRESS 2
/* Macros. */
#define BUF ((struct uip_tcpip_hdr *)&uip_buf[UIP_LLH_LEN])
#define FBUF ((struct uip_tcpip_hdr *)&uip_reassbuf[0])
#define ICMPBUF ((struct uip_icmpip_hdr *)&uip_buf[UIP_LLH_LEN])
#define UDPBUF ((struct uip_udpip_hdr *)&uip_buf[UIP_LLH_LEN])
#if UIP_STATISTICS == 1
struct uip_stats uip_stat;
#define UIP_STAT(s) s
#else
#define UIP_STAT(s)
#endif /* UIP_STATISTICS == 1 */
#if UIP_LOGGING == 1
#include <avr/pgmspace.h>
#include <stdio.h>
void uip_log_P(PGM_P msg);
#undef PSTR
#define PSTR(s) (__extension__({static const char __c[] __attribute__ (( section (".progmem") )) = (s); &__c[0];}))
#define UIP_LOG(m) uip_log_P(PSTR(m))
#else
#define UIP_LOG(m)
#endif /* UIP_LOGGING == 1 */
#if ! UIP_ARCH_ADD32
void
uip_add32(u8_t *op32, u16_t op16)
{
uip_acc32[3] = op32[3] + (op16 & 0xff);
uip_acc32[2] = op32[2] + (op16 >> 8);
uip_acc32[1] = op32[1];
uip_acc32[0] = op32[0];
if(uip_acc32[2] < (op16 >> 8)) {
++uip_acc32[1];
if(uip_acc32[1] == 0) {
++uip_acc32[0];
}
}
if(uip_acc32[3] < (op16 & 0xff)) {
++uip_acc32[2];
if(uip_acc32[2] == 0) {
++uip_acc32[1];
if(uip_acc32[1] == 0) {
++uip_acc32[0];
}
}
}
}
#endif /* UIP_ARCH_ADD32 */
#if ! UIP_ARCH_CHKSUM
/*---------------------------------------------------------------------------*/
static u16_t
chksum(u16_t sum, const u8_t *data, u16_t len)
{
u16_t t;
const u8_t *dataptr;
const u8_t *last_byte;
dataptr = data;
last_byte = data + len - 1;
while(dataptr < last_byte) { /* At least two more bytes */
t = (dataptr[0] << 8) + dataptr[1];
sum += t;
if(sum < t) {
sum++; /* carry */
}
dataptr += 2;
}
if(dataptr == last_byte) {
t = (dataptr[0] << 8) + 0;
sum += t;
if(sum < t) {
sum++; /* carry */
}
}
/* Return sum in host byte order. */
return sum;
}
/*---------------------------------------------------------------------------*/
u16_t
uip_chksum(u16_t *data, u16_t len)
{
return uip_htons(chksum(0, (u8_t *)data, len));
}
/*---------------------------------------------------------------------------*/
#ifndef UIP_ARCH_IPCHKSUM
u16_t
uip_ipchksum(void)
{
u16_t sum;
sum = chksum(0, &uip_buf[UIP_LLH_LEN], UIP_IPH_LEN);
DEBUG_PRINTF("uip_ipchksum: sum 0x%04x\n", sum);
return (sum == 0) ? 0xffff : uip_htons(sum);
}
#endif
/*---------------------------------------------------------------------------*/
static u16_t
upper_layer_chksum(u8_t proto)
{
u16_t upper_layer_len;
u16_t sum;
#if UIP_CONF_IPV6
upper_layer_len = (((u16_t)(BUF->len[0]) << 8) + BUF->len[1]);
#else /* UIP_CONF_IPV6 */
upper_layer_len = (((u16_t)(BUF->len[0]) << 8) + BUF->len[1]) - UIP_IPH_LEN;
#endif /* UIP_CONF_IPV6 */
/* First sum pseudoheader. */
/* IP protocol and length fields. This addition cannot carry. */
sum = upper_layer_len + proto;
/* Sum IP source and destination addresses. */
sum = chksum(sum, (u8_t *)&BUF->srcipaddr[0], 2 * sizeof(uip_ipaddr_t));
/* Sum TCP header and data. */
sum = chksum(sum, &uip_buf[UIP_IPH_LEN + UIP_LLH_LEN],
upper_layer_len);
return (sum == 0) ? 0xffff : uip_htons(sum);
}
/*---------------------------------------------------------------------------*/
#if UIP_CONF_IPV6
u16_t
uip_icmp6chksum(void)
{
return upper_layer_chksum(UIP_PROTO_ICMP6);
}
#endif /* UIP_CONF_IPV6 */
/*---------------------------------------------------------------------------*/
u16_t
uip_tcpchksum(void)
{
return upper_layer_chksum(UIP_PROTO_TCP);
}
/*---------------------------------------------------------------------------*/
#if UIP_UDP_CHECKSUMS
u16_t
uip_udpchksum(void)
{
return upper_layer_chksum(UIP_PROTO_UDP);
}
#endif /* UIP_UDP_CHECKSUMS */
#endif /* UIP_ARCH_CHKSUM */
/*---------------------------------------------------------------------------*/
void
uip_init(void)
{
for(c = 0; c < UIP_LISTENPORTS; ++c) {
uip_listenports[c] = 0;
}
for(c = 0; c < UIP_CONNS; ++c) {
uip_conns[c].tcpstateflags = UIP_CLOSED;
}
#if UIP_ACTIVE_OPEN
lastport = 1024;
#endif /* UIP_ACTIVE_OPEN */
#if UIP_UDP
for(c = 0; c < UIP_UDP_CONNS; ++c) {
uip_udp_conns[c].lport = 0;
}
#endif /* UIP_UDP */
/* IPv4 initialization. */
#if UIP_FIXEDADDR == 0
/* uip_hostaddr[0] = uip_hostaddr[1] = 0;*/
#endif /* UIP_FIXEDADDR */
}
/*---------------------------------------------------------------------------*/
#if UIP_ACTIVE_OPEN
struct uip_conn *
uip_connect(uip_ipaddr_t *ripaddr, u16_t rport, tcp_appcall_fn *app)
{
register struct uip_conn *conn, *cconn;
/* Find an unused local port. */
again:
++lastport;
if(lastport >= 32000) {
lastport = 4096;
}
/* Check if this port is already in use, and if so try to find
another one. */
for(c = 0; c < UIP_CONNS; ++c) {
conn = &uip_conns[c];
if(conn->tcpstateflags != UIP_CLOSED &&
conn->lport == uip_htons(lastport)) {
goto again;
}
}
conn = 0;
for(c = 0; c < UIP_CONNS; ++c) {
cconn = &uip_conns[c];
if(cconn->tcpstateflags == UIP_CLOSED) {
conn = cconn;
break;
}
if(cconn->tcpstateflags == UIP_TIME_WAIT) {
if(conn == 0 ||
cconn->timer > conn->timer) {
conn = cconn;
}
}
}
if(conn == 0) {
return 0;
}
conn->appcall = app;
conn->tcpstateflags = UIP_SYN_SENT;
conn->snd_nxt[0] = iss[0];
conn->snd_nxt[1] = iss[1];
conn->snd_nxt[2] = iss[2];
conn->snd_nxt[3] = iss[3];
conn->initialmss = conn->mss = UIP_TCP_MSS;
conn->len = 1; /* TCP length of the SYN is one. */
conn->nrtx = 0;
conn->timer = 1; /* Send the SYN next time around. */
conn->rto = UIP_RTO;
conn->sa = 0;
conn->sv = 16; /* Initial value of the RTT variance. */
conn->lport = uip_htons(lastport);
conn->rport = rport;
uip_ipaddr_copy(&conn->ripaddr, ripaddr);
return conn;
}
#endif /* UIP_ACTIVE_OPEN */
/*---------------------------------------------------------------------------*/
#if UIP_UDP
struct uip_udp_conn *
uip_udp_new(uip_ipaddr_t *ripaddr, u16_t rport, udp_appcall_fn *app)
{
register struct uip_udp_conn *conn;
/* Find an unused local port. */
again:
++lastport;
if(lastport >= 32000) {
lastport = 4096;
}
for(c = 0; c < UIP_UDP_CONNS; ++c) {
if(uip_udp_conns[c].lport == uip_htons(lastport)) {
goto again;
}
}
conn = 0;
for(c = 0; c < UIP_UDP_CONNS; ++c) {
if(uip_udp_conns[c].lport == 0) {
conn = &uip_udp_conns[c];
break;
}
}
if(conn == 0) {
return 0;
}
conn->lport = UIP_HTONS(lastport);
conn->rport = rport;
conn->appcall = app;
if(ripaddr == NULL) {
memset(conn->ripaddr, 0, sizeof(uip_ipaddr_t));
} else {
uip_ipaddr_copy(&conn->ripaddr, ripaddr);
}
conn->ttl = UIP_TTL;
return conn;
}
#endif /* UIP_UDP */
/*---------------------------------------------------------------------------*/
void
uip_unlisten(u16_t port)
{
for(c = 0; c < UIP_LISTENPORTS; ++c) {
if(uip_listenports[c] == port) {
uip_listenports[c] = 0;
return;
}
}
}
/*---------------------------------------------------------------------------*/
int
uip_listen(u16_t port,tcp_appcall_fn *app)
{
for(c = 0; c < UIP_LISTENPORTS; ++c) {
if(uip_listenports[c] == 0) {
uip_listenports[c] = port;
uip_listenapps[c] = app;
return 1;
}
}
return 0;
}
/*---------------------------------------------------------------------------*/
/* XXX: IP fragment reassembly: not well-tested. */
#if UIP_REASSEMBLY && !UIP_CONF_IPV6
#define UIP_REASS_BUFSIZE (UIP_BUFSIZE - UIP_LLH_LEN)
static u8_t uip_reassbuf[UIP_REASS_BUFSIZE];
static u8_t uip_reassbitmap[UIP_REASS_BUFSIZE / (8 * 8)];
static const u8_t bitmap_bits[8] = {0xff, 0x7f, 0x3f, 0x1f,
0x0f, 0x07, 0x03, 0x01};
static u16_t uip_reasslen;
static u8_t uip_reassflags;
#define UIP_REASS_FLAG_LASTFRAG 0x01
static u8_t uip_reasstmr;
#define IP_MF 0x20
static u8_t
uip_reass(void)
{
u16_t offset, len;
u16_t i;
/* If ip_reasstmr is zero, no packet is present in the buffer, so we
write the IP header of the fragment into the reassembly
buffer. The timer is updated with the maximum age. */
if(uip_reasstmr == 0) {
memcpy(uip_reassbuf, &BUF->vhl, UIP_IPH_LEN);
uip_reasstmr = UIP_REASS_MAXAGE;
uip_reassflags = 0;
/* Clear the bitmap. */
memset(uip_reassbitmap, 0, sizeof(uip_reassbitmap));
}
/* Check if the incoming fragment matches the one currently present
in the reasembly buffer. If so, we proceed with copying the
fragment into the buffer. */
if(BUF->srcipaddr[0] == FBUF->srcipaddr[0] &&
BUF->srcipaddr[1] == FBUF->srcipaddr[1] &&
BUF->destipaddr[0] == FBUF->destipaddr[0] &&
BUF->destipaddr[1] == FBUF->destipaddr[1] &&
BUF->ipid[0] == FBUF->ipid[0] &&
BUF->ipid[1] == FBUF->ipid[1]) {
len = (BUF->len[0] << 8) + BUF->len[1] - (BUF->vhl & 0x0f) * 4;
offset = (((BUF->ipoffset[0] & 0x3f) << 8) + BUF->ipoffset[1]) * 8;
/* If the offset or the offset + fragment length overflows the
reassembly buffer, we discard the entire packet. */
if(offset > UIP_REASS_BUFSIZE ||
offset + len > UIP_REASS_BUFSIZE) {
uip_reasstmr = 0;
goto nullreturn;
}
/* Copy the fragment into the reassembly buffer, at the right
offset. */
memcpy(&uip_reassbuf[UIP_IPH_LEN + offset],
(char *)BUF + (int)((BUF->vhl & 0x0f) * 4),
len);
/* Update the bitmap. */
if(offset / (8 * 8) == (offset + len) / (8 * 8)) {
/* If the two endpoints are in the same byte, we only update
that byte. */
uip_reassbitmap[offset / (8 * 8)] |=
bitmap_bits[(offset / 8 ) & 7] &
~bitmap_bits[((offset + len) / 8 ) & 7];
} else {
/* If the two endpoints are in different bytes, we update the
bytes in the endpoints and fill the stuff inbetween with
0xff. */
uip_reassbitmap[offset / (8 * 8)] |=
bitmap_bits[(offset / 8 ) & 7];
for(i = 1 + offset / (8 * 8); i < (offset + len) / (8 * 8); ++i) {
uip_reassbitmap[i] = 0xff;
}
uip_reassbitmap[(offset + len) / (8 * 8)] |=
~bitmap_bits[((offset + len) / 8 ) & 7];
}
/* If this fragment has the More Fragments flag set to zero, we
know that this is the last fragment, so we can calculate the
size of the entire packet. We also set the
IP_REASS_FLAG_LASTFRAG flag to indicate that we have received
the final fragment. */
if((BUF->ipoffset[0] & IP_MF) == 0) {
uip_reassflags |= UIP_REASS_FLAG_LASTFRAG;
uip_reasslen = offset + len;
}
/* Finally, we check if we have a full packet in the buffer. We do
this by checking if we have the last fragment and if all bits
in the bitmap are set. */
if(uip_reassflags & UIP_REASS_FLAG_LASTFRAG) {
/* Check all bytes up to and including all but the last byte in
the bitmap. */
for(i = 0; i < uip_reasslen / (8 * 8) - 1; ++i) {
if(uip_reassbitmap[i] != 0xff) {
goto nullreturn;
}
}
/* Check the last byte in the bitmap. It should contain just the
right amount of bits. */
if(uip_reassbitmap[uip_reasslen / (8 * 8)] !=
(u8_t)~bitmap_bits[uip_reasslen / 8 & 7]) {
goto nullreturn;
}
/* If we have come this far, we have a full packet in the
buffer, so we allocate a pbuf and copy the packet into it. We
also reset the timer. */
uip_reasstmr = 0;
memcpy(BUF, FBUF, uip_reasslen);
/* Pretend to be a "normal" (i.e., not fragmented) IP packet
from now on. */
BUF->ipoffset[0] = BUF->ipoffset[1] = 0;
BUF->len[0] = uip_reasslen >> 8;
BUF->len[1] = uip_reasslen & 0xff;
BUF->ipchksum = 0;
BUF->ipchksum = ~(uip_ipchksum());
return uip_reasslen;
}
}
nullreturn:
return 0;
}
#endif /* UIP_REASSEMBLY */
/*---------------------------------------------------------------------------*/
static void
uip_add_rcv_nxt(u16_t n)
{
uip_add32(uip_conn->rcv_nxt, n);
uip_conn->rcv_nxt[0] = uip_acc32[0];
uip_conn->rcv_nxt[1] = uip_acc32[1];
uip_conn->rcv_nxt[2] = uip_acc32[2];
uip_conn->rcv_nxt[3] = uip_acc32[3];
}
/*---------------------------------------------------------------------------*/
void
uip_process(u8_t flag)
{
register struct uip_conn *uip_connr = uip_conn;
/* Whether this packet was sliced (truncated) by the network layer */
uint8_t packet_sliced = 0;
#if UIP_UDP
if(flag == UIP_UDP_SEND_CONN) {
goto udp_send;
}
#endif /* UIP_UDP */
uip_sappdata = uip_appdata = &uip_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN];
/* Check if we were invoked because of a poll request for a
particular connection. */
if(flag == UIP_POLL_REQUEST) {
if((uip_connr->tcpstateflags & UIP_TS_MASK) == UIP_ESTABLISHED &&
!uip_outstanding(uip_connr)) {
uip_flags = UIP_POLL;
UIP_APPCALL();
goto appsend;
}
goto drop;
/* Check if we were invoked because of the perodic timer fireing. */
} else if(flag == UIP_TIMER) {
#if UIP_REASSEMBLY
if(uip_reasstmr != 0) {
--uip_reasstmr;
}
#endif /* UIP_REASSEMBLY */
/* Increase the initial sequence number. */
if(++iss[3] == 0) {
if(++iss[2] == 0) {
if(++iss[1] == 0) {
++iss[0];
}
}
}
/* Reset the length variables. */
uip_len = 0;
uip_slen = 0;
/* Check if the connection is in a state in which we simply wait
for the connection to time out. If so, we increase the
connection's timer and remove the connection if it times
out. */
if(uip_connr->tcpstateflags == UIP_TIME_WAIT ||
uip_connr->tcpstateflags == UIP_FIN_WAIT_2) {
++(uip_connr->timer);
if(uip_connr->timer == UIP_TIME_WAIT_TIMEOUT) {
uip_connr->tcpstateflags = UIP_CLOSED;
}
} else if(uip_connr->tcpstateflags != UIP_CLOSED) {
/* If the connection has outstanding data, we increase the
connection's timer and see if it has reached the RTO value
in which case we retransmit. */
if(uip_outstanding(uip_connr)) {
if(uip_connr->timer-- == 0) {
if(uip_connr->nrtx == UIP_MAXRTX ||
((uip_connr->tcpstateflags == UIP_SYN_SENT ||
uip_connr->tcpstateflags == UIP_SYN_RCVD) &&
uip_connr->nrtx == UIP_MAXSYNRTX)) {
uip_connr->tcpstateflags = UIP_CLOSED;
/* We call UIP_APPCALL() with uip_flags set to
UIP_TIMEDOUT to inform the application that the
connection has timed out. */
uip_flags = UIP_TIMEDOUT;
UIP_APPCALL();
/* We also send a reset packet to the remote host. */
BUF->flags = TCP_RST | TCP_ACK;
goto tcp_send_nodata;
}
/* Exponential backoff. */
uip_connr->timer = UIP_RTO << (uip_connr->nrtx > 4?
4:
uip_connr->nrtx);
++(uip_connr->nrtx);
/* Ok, so we need to retransmit. We do this differently
depending on which state we are in. In ESTABLISHED, we
call upon the application so that it may prepare the
data for the retransmit. In SYN_RCVD, we resend the
SYNACK that we sent earlier and in LAST_ACK we have to
retransmit our FINACK. */
UIP_STAT(++uip_stat.tcp.rexmit);
switch(uip_connr->tcpstateflags & UIP_TS_MASK) {
case UIP_SYN_RCVD:
/* In the SYN_RCVD state, we should retransmit our
SYNACK. */
goto tcp_send_synack;
#if UIP_ACTIVE_OPEN
case UIP_SYN_SENT:
/* In the SYN_SENT state, we retransmit out SYN. */
BUF->flags = 0;
goto tcp_send_syn;
#endif /* UIP_ACTIVE_OPEN */
case UIP_ESTABLISHED:
/* In the ESTABLISHED state, we call upon the application
to do the actual retransmit after which we jump into
the code for sending out the packet (the apprexmit
label). */
uip_flags = UIP_REXMIT;
UIP_APPCALL();
goto apprexmit;
case UIP_FIN_WAIT_1:
case UIP_CLOSING:
case UIP_LAST_ACK:
/* In all these states we should retransmit a FINACK. */
goto tcp_send_finack;
}
}
} else if((uip_connr->tcpstateflags & UIP_TS_MASK) == UIP_ESTABLISHED) {
/* If there was no need for a retransmission, we poll the
application for new data. */
uip_flags = UIP_POLL;
UIP_APPCALL();
goto appsend;
}
}
goto drop;
}
#if UIP_UDP
if(flag == UIP_UDP_TIMER) {
if(uip_udp_conn->lport != 0) {
uip_conn = NULL;
uip_sappdata = uip_appdata = &uip_buf[UIP_LLH_LEN + UIP_IPUDPH_LEN];
uip_len = uip_slen = 0;
uip_flags = UIP_POLL;
UIP_UDP_APPCALL();
goto udp_send;
} else {
goto drop;
}
}
#endif
/* This is where the input processing starts. */
UIP_STAT(++uip_stat.ip.recv);
/* Start of IP input header processing code. */
#if UIP_CONF_IPV6
/* Check validity of the IP header. */
if((BUF->vtc & 0xf0) != 0x60) { /* IP version and header length. */
UIP_STAT(++uip_stat.ip.drop);
UIP_STAT(++uip_stat.ip.vhlerr);
UIP_LOG("ipv6: invalid version.");
goto drop;
}
#else /* UIP_CONF_IPV6 */
/* Check validity of the IP header. */
if(BUF->vhl != 0x45) { /* IP version and header length. */
UIP_STAT(++uip_stat.ip.drop);
UIP_STAT(++uip_stat.ip.vhlerr);
UIP_LOG("ip: invalid version or header length.");
goto drop;
}
#endif /* UIP_CONF_IPV6 */
/* Check the size of the packet. If the size reported to us in
uip_len is smaller the size reported in the IP header, we assume
that the packet has been corrupted in transit. If the size of
uip_len is larger than the size reported in the IP packet header,
the packet has been padded and we set uip_len to the correct
value.. */
if(((unsigned)BUF->len[0] << 8) + BUF->len[1] <= uip_len) {
uip_len = (BUF->len[0] << 8) + BUF->len[1];
#if UIP_CONF_IPV6
uip_len += 40; /* The length reported in the IPv6 header is the
length of the payload that follows the
header. However, uIP uses the uip_len variable
for holding the size of the entire packet,
including the IP header. For IPv4 this is not a
problem as the length field in the IPv4 header
contains the length of the entire packet. But
for IPv6 we need to add the size of the IPv6
header (40 bytes). */
#endif /* UIP_CONF_IPV6 */
} else {
UIP_LOG("ip: packet shorter than reported in IP header.");
packet_sliced = 1;
UIP_LOG("Assuming it was sliced by the network layer.");
}
#if !UIP_CONF_IPV6
/* Check the fragment flag. */
if((BUF->ipoffset[0] & 0x3f) != 0 ||
BUF->ipoffset[1] != 0) {
#if UIP_REASSEMBLY
uip_len = uip_reass();
if(uip_len == 0) {
goto drop;
}
#else /* UIP_REASSEMBLY */
UIP_STAT(++uip_stat.ip.drop);
UIP_STAT(++uip_stat.ip.fragerr);
UIP_LOG("ip: fragment dropped.");
goto drop;
#endif /* UIP_REASSEMBLY */
}
#endif /* UIP_CONF_IPV6 */
if(uip_ipaddr_cmp(uip_hostaddr, all_zeroes_addr)) {
/* If we are configured to use ping IP address configuration and
hasn't been assigned an IP address yet, we accept all ICMP
packets. */
#if UIP_PINGADDRCONF && !UIP_CONF_IPV6
if(BUF->proto == UIP_PROTO_ICMP) {
UIP_LOG("ip: possible ping config packet received.");
goto icmp_input;
} else {
UIP_LOG("ip: packet dropped since no address assigned.");
goto drop;
}
#endif /* UIP_PINGADDRCONF */
} else {
/* If IP broadcast support is configured, we check for a broadcast
UDP packet, which may be destined to us. */
#if UIP_BROADCAST
DEBUG_PRINTF("UDP IP checksum 0x%04x\n", uip_ipchksum());
if(BUF->proto == UIP_PROTO_UDP &&
uip_ipaddr_cmp(BUF->destipaddr, all_ones_addr)
/*&&
uip_ipchksum() == 0xffff*/) {
goto udp_input;
}
#endif /* UIP_BROADCAST */
/* Check if the packet is destined for our IP address. */
#if !UIP_CONF_IPV6
if(!uip_ipaddr_cmp(BUF->destipaddr, uip_hostaddr)) {
UIP_STAT(++uip_stat.ip.drop);
goto drop;
}
#else /* UIP_CONF_IPV6 */
/* For IPv6, packet reception is a little trickier as we need to
make sure that we listen to certain multicast addresses (all
hosts multicast address, and the solicited-node multicast
address) as well. However, we will cheat here and accept all
multicast packets that are sent to the ff02::/16 addresses. */
if(!uip_ipaddr_cmp(BUF->destipaddr, uip_hostaddr) &&
BUF->destipaddr[0] != UIP_HTONS(0xff02)) {
UIP_STAT(++uip_stat.ip.drop);
goto drop;
}
#endif /* UIP_CONF_IPV6 */
}
#if !UIP_CONF_IPV6
if(uip_ipchksum() != 0xffff) { /* Compute and check the IP header
checksum. */
UIP_STAT(++uip_stat.ip.drop);
UIP_STAT(++uip_stat.ip.chkerr);
UIP_LOG("ip: bad checksum.");
if (packet_sliced)
UIP_LOG("Ignoring because packet was sliced.");
else
goto drop;
}
#endif /* UIP_CONF_IPV6 */
if(BUF->proto == UIP_PROTO_TCP) { /* Check for TCP packet. If so,
proceed with TCP input
processing. */
goto tcp_input;
}
#if UIP_UDP
if(BUF->proto == UIP_PROTO_UDP) {
goto udp_input;
}
#endif /* UIP_UDP */
#if !UIP_CONF_IPV6
/* ICMPv4 processing code follows. */
if(BUF->proto != UIP_PROTO_ICMP) { /* We only allow ICMP packets from
here. */
UIP_STAT(++uip_stat.ip.drop);
UIP_STAT(++uip_stat.ip.protoerr);
UIP_LOG("ip: neither tcp nor icmp.");
goto drop;
}
#if UIP_PINGADDRCONF
icmp_input:
#endif /* UIP_PINGADDRCONF */
UIP_STAT(++uip_stat.icmp.recv);
/* ICMP echo (i.e., ping) processing. This is simple, we only change
the ICMP type from ECHO to ECHO_REPLY and adjust the ICMP
checksum before we return the packet. */
if(ICMPBUF->type != ICMP_ECHO) {
UIP_STAT(++uip_stat.icmp.drop);
UIP_STAT(++uip_stat.icmp.typeerr);
UIP_LOG("icmp: not icmp echo.");
goto drop;
}