forked from conclusiveeng/lib9p
-
Notifications
You must be signed in to change notification settings - Fork 0
/
request.c
1432 lines (1255 loc) · 38.2 KB
/
request.c
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
/*
* Copyright 2016 Jakub Klama <[email protected]>
* All rights reserved
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted providing 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.
*
* 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.
*
*/
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <errno.h>
#include <sys/param.h>
#include <sys/uio.h>
#if defined(__FreeBSD__)
#include <sys/sbuf.h>
#else
#include "sbuf/sbuf.h"
#endif
#include "lib9p.h"
#include "lib9p_impl.h"
#include "fcall.h"
#include "fid.h"
#include "hashtable.h"
#include "log.h"
#include "linux_errno.h"
#include "backend/backend.h"
#include "threadpool.h"
#define N(x) (sizeof(x) / sizeof(x[0]))
static int l9p_dispatch_tversion(struct l9p_request *req);
static int l9p_dispatch_tattach(struct l9p_request *req);
static int l9p_dispatch_tclunk(struct l9p_request *req);
static int l9p_dispatch_tcreate(struct l9p_request *req);
static int l9p_dispatch_topen(struct l9p_request *req);
static int l9p_dispatch_tread(struct l9p_request *req);
static int l9p_dispatch_tremove(struct l9p_request *req);
static int l9p_dispatch_tstat(struct l9p_request *req);
static int l9p_dispatch_twalk(struct l9p_request *req);
static int l9p_dispatch_twrite(struct l9p_request *req);
static int l9p_dispatch_twstat(struct l9p_request *req);
static int l9p_dispatch_tstatfs(struct l9p_request *req);
static int l9p_dispatch_tlopen(struct l9p_request *req);
static int l9p_dispatch_tlcreate(struct l9p_request *req);
static int l9p_dispatch_tsymlink(struct l9p_request *req);
static int l9p_dispatch_tmknod(struct l9p_request *req);
static int l9p_dispatch_trename(struct l9p_request *req);
static int l9p_dispatch_treadlink(struct l9p_request *req);
static int l9p_dispatch_tgetattr(struct l9p_request *req);
static int l9p_dispatch_tsetattr(struct l9p_request *req);
static int l9p_dispatch_txattrwalk(struct l9p_request *req);
static int l9p_dispatch_txattrcreate(struct l9p_request *req);
static int l9p_dispatch_treaddir(struct l9p_request *req);
static int l9p_dispatch_tfsync(struct l9p_request *req);
static int l9p_dispatch_tlock(struct l9p_request *req);
static int l9p_dispatch_tgetlock(struct l9p_request *req);
static int l9p_dispatch_tlink(struct l9p_request *req);
static int l9p_dispatch_tmkdir(struct l9p_request *req);
static int l9p_dispatch_trenameat(struct l9p_request *req);
static int l9p_dispatch_tunlinkat(struct l9p_request *req);
/*
* Each Txxx handler has a "must run" flag. If it is false,
* we check for a flush request before calling the handler.
* If a flush is already requested we can instantly fail the
* request with EINTR.
*
* Tclunk and Tremove must run because they make their fids
* become invalid. Tversion and Tattach should never get
* a flush request applied (it makes no sense as the connection
* is not really running yet), so it should be harmless to
* set them either way, but for now we have them as must-run.
* Flushing a Tflush is not really allowed either so we keep
* these as must-run too (although they run without being done
* threaded anyway).
*/
struct l9p_handler {
enum l9p_ftype type;
int (*handler)(struct l9p_request *);
bool must_run;
};
static const struct l9p_handler l9p_handlers_no_version[] = {
{L9P_TVERSION, l9p_dispatch_tversion, true},
};
static const struct l9p_handler l9p_handlers_base[] = {
{L9P_TVERSION, l9p_dispatch_tversion, true},
{L9P_TATTACH, l9p_dispatch_tattach, true},
{L9P_TCLUNK, l9p_dispatch_tclunk, true},
{L9P_TFLUSH, l9p_threadpool_tflush, true},
{L9P_TCREATE, l9p_dispatch_tcreate, false},
{L9P_TOPEN, l9p_dispatch_topen, false},
{L9P_TREAD, l9p_dispatch_tread, false},
{L9P_TWRITE, l9p_dispatch_twrite, false},
{L9P_TREMOVE, l9p_dispatch_tremove, true},
{L9P_TSTAT, l9p_dispatch_tstat, false},
{L9P_TWALK, l9p_dispatch_twalk, false},
{L9P_TWSTAT, l9p_dispatch_twstat, false}
};
static const struct l9p_handler l9p_handlers_dotu[] = {
{L9P_TVERSION, l9p_dispatch_tversion, true},
{L9P_TATTACH, l9p_dispatch_tattach, true},
{L9P_TCLUNK, l9p_dispatch_tclunk, true},
{L9P_TFLUSH, l9p_threadpool_tflush, true},
{L9P_TCREATE, l9p_dispatch_tcreate, false},
{L9P_TOPEN, l9p_dispatch_topen, false},
{L9P_TREAD, l9p_dispatch_tread, false},
{L9P_TWRITE, l9p_dispatch_twrite, false},
{L9P_TREMOVE, l9p_dispatch_tremove, true},
{L9P_TSTAT, l9p_dispatch_tstat, false},
{L9P_TWALK, l9p_dispatch_twalk, false},
{L9P_TWSTAT, l9p_dispatch_twstat, false}
};
static const struct l9p_handler l9p_handlers_dotL[] = {
{L9P_TVERSION, l9p_dispatch_tversion, true},
{L9P_TATTACH, l9p_dispatch_tattach, true},
{L9P_TCLUNK, l9p_dispatch_tclunk, true},
{L9P_TFLUSH, l9p_threadpool_tflush, true},
{L9P_TCREATE, l9p_dispatch_tcreate, false},
{L9P_TOPEN, l9p_dispatch_topen, false},
{L9P_TREAD, l9p_dispatch_tread, false},
{L9P_TWRITE, l9p_dispatch_twrite, false},
{L9P_TREMOVE, l9p_dispatch_tremove, true},
{L9P_TSTAT, l9p_dispatch_tstat, false},
{L9P_TWALK, l9p_dispatch_twalk, false},
{L9P_TWSTAT, l9p_dispatch_twstat, false},
{L9P_TSTATFS, l9p_dispatch_tstatfs, false},
{L9P_TLOPEN, l9p_dispatch_tlopen, false},
{L9P_TLCREATE, l9p_dispatch_tlcreate, false},
{L9P_TSYMLINK, l9p_dispatch_tsymlink, false},
{L9P_TMKNOD, l9p_dispatch_tmknod, false},
{L9P_TRENAME, l9p_dispatch_trename, false},
{L9P_TREADLINK, l9p_dispatch_treadlink, false},
{L9P_TGETATTR, l9p_dispatch_tgetattr, false},
{L9P_TSETATTR, l9p_dispatch_tsetattr, false},
{L9P_TXATTRWALK, l9p_dispatch_txattrwalk, false},
{L9P_TXATTRCREATE, l9p_dispatch_txattrcreate, false},
{L9P_TREADDIR, l9p_dispatch_treaddir, false},
{L9P_TFSYNC, l9p_dispatch_tfsync, false},
{L9P_TLOCK, l9p_dispatch_tlock, true},
{L9P_TGETLOCK, l9p_dispatch_tgetlock, true},
{L9P_TLINK, l9p_dispatch_tlink, false},
{L9P_TMKDIR, l9p_dispatch_tmkdir, false},
{L9P_TRENAMEAT, l9p_dispatch_trenameat, false},
{L9P_TUNLINKAT, l9p_dispatch_tunlinkat, false},
};
/*
* NB: version index 0 is reserved for new connections, and
* is a protocol that handles only L9P_TVERSION. Once we get a
* valid version, we start a new session using its dispatch table.
*/
static const struct {
const char *name;
const struct l9p_handler *handlers;
int n_handlers;
} l9p_versions[] = {
{ "<none>", l9p_handlers_no_version, N(l9p_handlers_no_version) },
{ "9P2000", l9p_handlers_base, N(l9p_handlers_base) },
{ "9P2000.u", l9p_handlers_dotu, N(l9p_handlers_dotu), },
{ "9P2000.L", l9p_handlers_dotL, N(l9p_handlers_dotL), },
};
/*
* Run the appropriate handler for this request.
* It's our caller's responsibility to respond.
*/
int
l9p_dispatch_request(struct l9p_request *req)
{
struct l9p_connection *conn;
#if defined(L9P_DEBUG)
struct sbuf *sb;
#endif
size_t i, n;
const struct l9p_handler *handlers, *hp;
bool flush_requested;
conn = req->lr_conn;
flush_requested = req->lr_flushstate == L9P_FLUSH_REQUESTED_PRE_START;
handlers = l9p_versions[conn->lc_version].handlers;
n = (size_t)l9p_versions[conn->lc_version].n_handlers;
for (hp = handlers, i = 0; i < n; hp++, i++)
if (req->lr_req.hdr.type == hp->type)
goto found;
hp = NULL;
found:
#if defined(L9P_DEBUG)
sb = sbuf_new_auto();
if (flush_requested) {
sbuf_cat(sb, "FLUSH requested pre-dispatch");
if (hp != NULL && hp->must_run)
sbuf_cat(sb, ", but must run");
sbuf_cat(sb, ": ");
}
l9p_describe_fcall(&req->lr_req, conn->lc_version, sb);
sbuf_finish(sb);
L9P_LOG(L9P_DEBUG, "%s", sbuf_data(sb));
sbuf_delete(sb);
#endif
if (hp != NULL) {
if (!flush_requested || hp->must_run)
return (hp->handler(req));
return (EINTR);
}
L9P_LOG(L9P_WARNING, "unknown request of type %d",
req->lr_req.hdr.type);
return (ENOSYS);
}
/*
* Translate BSD errno to 9P2000/9P2000.u errno.
*/
static inline int
e29p(int errnum)
{
static int const table[] = {
[ENOTEMPTY] = EPERM,
[EDQUOT] = EPERM,
[ENOSYS] = EPERM, /* ??? */
};
if ((size_t)errnum < N(table) && table[errnum] != 0)
return (table[errnum]);
if (errnum <= ERANGE)
return (errnum);
return (EIO); /* ??? */
}
/*
* Translate BSD errno to Linux errno.
*/
static inline int
e2linux(int errnum)
{
static int const table[] = {
[EDEADLK] = LINUX_EDEADLK,
[EAGAIN] = LINUX_EAGAIN,
[EINPROGRESS] = LINUX_EINPROGRESS,
[EALREADY] = LINUX_EALREADY,
[ENOTSOCK] = LINUX_ENOTSOCK,
[EDESTADDRREQ] = LINUX_EDESTADDRREQ,
[EMSGSIZE] = LINUX_EMSGSIZE,
[EPROTOTYPE] = LINUX_EPROTOTYPE,
[ENOPROTOOPT] = LINUX_ENOPROTOOPT,
[EPROTONOSUPPORT] = LINUX_EPROTONOSUPPORT,
[ESOCKTNOSUPPORT] = LINUX_ESOCKTNOSUPPORT,
[EOPNOTSUPP] = LINUX_EOPNOTSUPP,
[EPFNOSUPPORT] = LINUX_EPFNOSUPPORT,
[EAFNOSUPPORT] = LINUX_EAFNOSUPPORT,
[EADDRINUSE] = LINUX_EADDRINUSE,
[EADDRNOTAVAIL] = LINUX_EADDRNOTAVAIL,
[ENETDOWN] = LINUX_ENETDOWN,
[ENETUNREACH] = LINUX_ENETUNREACH,
[ENETRESET] = LINUX_ENETRESET,
[ECONNABORTED] = LINUX_ECONNABORTED,
[ECONNRESET] = LINUX_ECONNRESET,
[ENOBUFS] = LINUX_ENOBUFS,
[EISCONN] = LINUX_EISCONN,
[ENOTCONN] = LINUX_ENOTCONN,
[ESHUTDOWN] = LINUX_ESHUTDOWN,
[ETOOMANYREFS] = LINUX_ETOOMANYREFS,
[ETIMEDOUT] = LINUX_ETIMEDOUT,
[ECONNREFUSED] = LINUX_ECONNREFUSED,
[ELOOP] = LINUX_ELOOP,
[ENAMETOOLONG] = LINUX_ENAMETOOLONG,
[EHOSTDOWN] = LINUX_EHOSTDOWN,
[EHOSTUNREACH] = LINUX_EHOSTUNREACH,
[ENOTEMPTY] = LINUX_ENOTEMPTY,
[EPROCLIM] = LINUX_EAGAIN,
[EUSERS] = LINUX_EUSERS,
[EDQUOT] = LINUX_EDQUOT,
[ESTALE] = LINUX_ESTALE,
[EREMOTE] = LINUX_EREMOTE,
/* EBADRPC = unmappable? */
/* ERPCMISMATCH = unmappable? */
/* EPROGUNAVAIL = unmappable? */
/* EPROGMISMATCH = unmappable? */
/* EPROCUNAVAIL = unmappable? */
[ENOLCK] = LINUX_ENOLCK,
[ENOSYS] = LINUX_ENOSYS,
/* EFTYPE = unmappable? */
/* EAUTH = unmappable? */
/* ENEEDAUTH = unmappable? */
[EIDRM] = LINUX_EIDRM,
[ENOMSG] = LINUX_ENOMSG,
[EOVERFLOW] = LINUX_EOVERFLOW,
[ECANCELED] = LINUX_ECANCELED,
[EILSEQ] = LINUX_EILSEQ,
/* EDOOFUS = unmappable? */
[EBADMSG] = LINUX_EBADMSG,
[EMULTIHOP] = LINUX_EMULTIHOP,
[ENOLINK] = LINUX_ENOLINK,
[EPROTO] = LINUX_EPROTO,
/* ENOTCAPABLE = unmappable? */
/* ECAPMODE = unmappable? */
#ifdef ENOTRECOVERABLE
[ENOTRECOVERABLE] = LINUX_ENOTRECOVERABLE,
#endif
#ifdef EOWNERDEAD
[EOWNERDEAD] = LINUX_EOWNERDEAD,
#endif
};
/*
* In case we want to return a raw Linux errno, allow negative
* values a la Linux kernel internals.
*
* Values up to ERANGE are shared across systems (see
* linux_errno.h), except for EAGAIN.
*/
if (errnum < 0)
return (-errnum);
if ((size_t)errnum < N(table) && table[errnum] != 0)
return (table[errnum]);
if (errnum <= ERANGE)
return (errnum);
L9P_LOG(L9P_WARNING, "cannot map errno %d to anything reasonable", errnum);
return (LINUX_ENOTRECOVERABLE); /* ??? */
}
/*
* Send response to request, or possibly just drop request.
* We also need to know whether to remove the request from
* the tag hash table.
*/
void
l9p_respond(struct l9p_request *req, bool drop, bool rmtag)
{
struct l9p_connection *conn = req->lr_conn;
size_t iosize;
#if defined(L9P_DEBUG)
struct sbuf *sb;
const char *ftype;
#endif
int error;
req->lr_resp.hdr.tag = req->lr_req.hdr.tag;
error = req->lr_error;
if (error == 0)
req->lr_resp.hdr.type = req->lr_req.hdr.type + 1;
else {
if (conn->lc_version == L9P_2000L) {
req->lr_resp.hdr.type = L9P_RLERROR;
req->lr_resp.error.errnum = (uint32_t)e2linux(error);
} else {
req->lr_resp.hdr.type = L9P_RERROR;
req->lr_resp.error.ename = strerror(error);
req->lr_resp.error.errnum = (uint32_t)e29p(error);
}
}
#if defined(L9P_DEBUG)
sb = sbuf_new_auto();
l9p_describe_fcall(&req->lr_resp, conn->lc_version, sb);
sbuf_finish(sb);
switch (req->lr_flushstate) {
case L9P_FLUSH_NONE:
ftype = "";
break;
case L9P_FLUSH_REQUESTED_PRE_START:
ftype = "FLUSH requested pre-dispatch: ";
break;
case L9P_FLUSH_REQUESTED_POST_START:
ftype = "FLUSH requested while running: ";
break;
case L9P_FLUSH_TOOLATE:
ftype = "FLUSH requested too late: ";
break;
}
L9P_LOG(L9P_DEBUG, "%s%s%s",
drop ? "DROP: " : "", ftype, sbuf_data(sb));
sbuf_delete(sb);
#endif
error = drop ? 0 :
l9p_pufcall(&req->lr_resp_msg, &req->lr_resp, conn->lc_version);
if (rmtag)
ht_remove(&conn->lc_requests, req->lr_req.hdr.tag);
if (error != 0) {
L9P_LOG(L9P_ERROR, "cannot pack response");
drop = true;
}
if (drop) {
conn->lc_lt.lt_drop_response(req,
req->lr_resp_msg.lm_iov, req->lr_resp_msg.lm_niov,
conn->lc_lt.lt_aux);
} else {
iosize = req->lr_resp_msg.lm_size;
/*
* Include I/O size in calculation for Rread and
* Rreaddir responses.
*/
if (req->lr_resp.hdr.type == L9P_RREAD ||
req->lr_resp.hdr.type == L9P_RREADDIR)
iosize += req->lr_resp.io.count;
conn->lc_lt.lt_send_response(req,
req->lr_resp_msg.lm_iov, req->lr_resp_msg.lm_niov,
iosize, conn->lc_lt.lt_aux);
}
l9p_freefcall(&req->lr_req);
l9p_freefcall(&req->lr_resp);
free(req);
}
/*
* This allows a caller to iterate through the data in a
* read or write request (creating the data if packing,
* scanning through it if unpacking). This is used for
* writing readdir entries, so mode should be L9P_PACK
* (but we allow L9P_UNPACK so that debug code can also scan
* through the data later, if desired).
*
* This relies on the Tread op having positioned the request's
* iov to the beginning of the data buffer (note the l9p_seek_iov
* in l9p_dispatch_tread).
*/
void
l9p_init_msg(struct l9p_message *msg, struct l9p_request *req,
enum l9p_pack_mode mode)
{
msg->lm_size = 0;
msg->lm_mode = mode;
msg->lm_cursor_iov = 0;
msg->lm_cursor_offset = 0;
msg->lm_niov = req->lr_data_niov;
memcpy(msg->lm_iov, req->lr_data_iov,
sizeof (struct iovec) * req->lr_data_niov);
}
enum fid_lookup_flags {
F_REQUIRE_OPEN = 0x01, /* require that the file be marked OPEN */
F_REQUIRE_DIR = 0x02, /* require that the file be marked ISDIR */
F_REQUIRE_XATTR = 0x04, /* require that the file be marked XATTR */
F_REQUIRE_AUTH = 0x08, /* require that the fid be marked AUTH */
F_FORBID_OPEN = 0x10, /* forbid that the file be marked OPEN */
F_FORBID_DIR = 0x20, /* forbid that the file be marked ISDIR */
F_FORBID_XATTR = 0x40, /* forbid that the file be marked XATTR */
F_ALLOW_AUTH = 0x80, /* allow that the fid be marked AUTH */
};
/*
* Look up a fid. It must correspond to a valid file, else we return
* the given errno (some "not a valid fid" calls must return EIO and
* some must return EINVAL and qemu returns ENOENT in other cases and
* so on, so we just provide a general "return this error number").
*
* Callers may also set constraints: fid must be (or not be) open,
* must be (or not be) a directory, must be (or not be) an xattr.
*
* Only one op has a fid that *must* be an auth fid. Most ops forbid
* auth fids So instead of FORBID we have ALLOW here and the default
* is FORBID.
*/
static inline int
fid_lookup(struct l9p_connection *conn, uint32_t fid, int err, int flags,
struct l9p_fid **afile)
{
struct l9p_fid *file;
file = ht_find(&conn->lc_files, fid);
if (file == NULL)
return (err);
/*
* As soon as we go multithreaded / async, this
* assert has to become "return EINVAL" or "return err".
*
* We may also need a way to mark a fid as
* "in async op" (valid for some purposes, but cannot be
* used elsewhere until async op is completed or aborted).
*
* For now, this serves for bug-detecting.
*/
assert(l9p_fid_isvalid(file));
/*
* Note that we're inline expanded and flags is constant,
* so unnecessary tests just drop out entirely.
*/
if ((flags & F_REQUIRE_OPEN) && !l9p_fid_isopen(file))
return (EINVAL);
if ((flags & F_FORBID_OPEN) && l9p_fid_isopen(file))
return (EINVAL);
if ((flags & F_REQUIRE_DIR) && !l9p_fid_isdir(file))
return (ENOTDIR);
if ((flags & F_FORBID_DIR) && l9p_fid_isdir(file))
return (EISDIR);
if ((flags & F_REQUIRE_XATTR) && !l9p_fid_isxattr(file))
return (EINVAL);
if ((flags & F_FORBID_XATTR) && l9p_fid_isxattr(file))
return (EINVAL);
if (l9p_fid_isauth(file)) {
if ((flags & (F_REQUIRE_AUTH | F_ALLOW_AUTH)) == 0)
return (EINVAL);
} else if (flags & F_REQUIRE_AUTH)
return (EINVAL);
*afile = file;
return (0);
}
/*
* Append variable-size stat object and adjust io count.
* Returns 0 if the entire stat object was packed, -1 if not.
* A fully packed object updates the request's io count.
*
* Caller must use their own private l9p_message object since
* a partially packed object will leave the message object in
* a useless state.
*
* Frees the stat object.
*/
int
l9p_pack_stat(struct l9p_message *msg, struct l9p_request *req,
struct l9p_stat *st)
{
struct l9p_connection *conn = req->lr_conn;
uint16_t size = l9p_sizeof_stat(st, conn->lc_version);
int ret = 0;
assert(msg->lm_mode == L9P_PACK);
if (req->lr_resp.io.count + size > req->lr_req.io.count ||
l9p_pustat(msg, st, conn->lc_version) < 0)
ret = -1;
else
req->lr_resp.io.count += size;
l9p_freestat(st);
return (ret);
}
static int
l9p_dispatch_tversion(struct l9p_request *req)
{
struct l9p_connection *conn = req->lr_conn;
struct l9p_server *server = conn->lc_server;
enum l9p_version remote_version = L9P_INVALID_VERSION;
size_t i;
const char *remote_version_name;
for (i = 0; i < N(l9p_versions); i++) {
if (strcmp(req->lr_req.version.version,
l9p_versions[i].name) == 0) {
remote_version = (enum l9p_version)i;
break;
}
}
if (remote_version == L9P_INVALID_VERSION) {
L9P_LOG(L9P_ERROR, "unsupported remote version: %s",
req->lr_req.version.version);
return (ENOSYS);
}
remote_version_name = l9p_versions[remote_version].name;
L9P_LOG(L9P_INFO, "remote version: %s", remote_version_name);
L9P_LOG(L9P_INFO, "local version: %s",
l9p_versions[server->ls_max_version].name);
conn->lc_version = MIN(remote_version, server->ls_max_version);
conn->lc_msize = MIN(req->lr_req.version.msize, conn->lc_msize);
conn->lc_max_io_size = conn->lc_msize - 24;
req->lr_resp.version.version = strdup(remote_version_name);
req->lr_resp.version.msize = conn->lc_msize;
return (0);
}
static int
l9p_dispatch_tattach(struct l9p_request *req)
{
struct l9p_connection *conn = req->lr_conn;
struct l9p_backend *be;
struct l9p_fid *fid;
int error;
/*
* We still don't have Tauth yet, but let's code this part
* anyway.
*
* Look up the auth fid first since if it fails we can just
* return immediately.
*/
if (req->lr_req.tattach.afid != L9P_NOFID) {
error = fid_lookup(conn, req->lr_req.tattach.afid, EINVAL,
F_REQUIRE_AUTH, &req->lr_fid2);
if (error)
return (error);
} else
req->lr_fid2 = NULL;
fid = l9p_connection_alloc_fid(conn, req->lr_req.hdr.fid);
if (fid == NULL)
return (EINVAL);
be = conn->lc_server->ls_backend;
req->lr_fid = fid;
/* For backend convenience, set NONUNAME on 9P2000. */
if (conn->lc_version == L9P_2000)
req->lr_req.tattach.n_uname = L9P_NONUNAME;
error = be->attach(be->softc, req);
/*
* On success, fid becomes valid; on failure, disconnect.
* It certainly *should* be a directory here...
*/
if (error == 0) {
l9p_fid_setvalid(fid);
if (req->lr_resp.rattach.qid.type & L9P_QTDIR)
l9p_fid_setdir(fid);
} else
l9p_connection_remove_fid(conn, fid);
return (error);
}
static int
l9p_dispatch_tclunk(struct l9p_request *req)
{
struct l9p_connection *conn = req->lr_conn;
struct l9p_backend *be;
struct l9p_fid *fid;
int error;
/* Note that clunk is the only way to dispose of an auth fid. */
error = fid_lookup(conn, req->lr_req.hdr.fid, ENOENT,
F_ALLOW_AUTH, &fid);
if (error)
return (error);
be = conn->lc_server->ls_backend;
l9p_fid_unsetvalid(fid);
/*
* If it's an xattr fid there must, by definition, be an
* xattrclunk. The xattrclunk function can only be NULL if
* xattrwalk and xattrcreate are NULL or always return error.
*
* Q: do we want to allow async xattrclunk in case of very
* large xattr create? This will make things difficult,
* so probably not.
*/
if (l9p_fid_isxattr(fid))
error = be->xattrclunk(be->softc, fid);
else
error = be->clunk(be->softc, fid);
/* fid is now gone regardless of any error return */
l9p_connection_remove_fid(conn, fid);
return (error);
}
static int
l9p_dispatch_tcreate(struct l9p_request *req)
{
struct l9p_connection *conn = req->lr_conn;
struct l9p_backend *be;
uint32_t dmperm;
int error;
/* Incoming fid must represent a directory that has not been opened. */
error = fid_lookup(conn, req->lr_req.hdr.fid, EINVAL,
F_REQUIRE_DIR | F_FORBID_OPEN, &req->lr_fid);
if (error)
return (error);
be = conn->lc_server->ls_backend;
dmperm = req->lr_req.tcreate.perm;
#define MKDIR_OR_SIMILAR \
(L9P_DMDIR | L9P_DMSYMLINK | L9P_DMNAMEDPIPE | L9P_DMSOCKET | L9P_DMDEVICE)
/*
* TODO:
* - check new file name
* - break out different kinds of create (file vs mkdir etc)
* - add async file-create (leaves req->lr_fid in limbo)
*
* A successful file-create changes the fid into an open file.
*/
error = be->create(be->softc, req);
if (error == 0 && (dmperm & MKDIR_OR_SIMILAR) == 0) {
l9p_fid_unsetdir(req->lr_fid);
l9p_fid_setopen(req->lr_fid);
}
return (error);
}
static int
l9p_dispatch_topen(struct l9p_request *req)
{
struct l9p_connection *conn = req->lr_conn;
struct l9p_backend *be;
int error;
error = fid_lookup(conn, req->lr_req.hdr.fid, ENOENT,
F_FORBID_OPEN | F_FORBID_XATTR, &req->lr_fid);
if (error)
return (error);
be = conn->lc_server->ls_backend;
/*
* TODO:
* - add async open (leaves req->lr_fid in limbo)
*/
error = be->open(be->softc, req);
if (error == 0)
l9p_fid_setopen(req->lr_fid);
return (error);
}
static int
l9p_dispatch_tread(struct l9p_request *req)
{
struct l9p_connection *conn = req->lr_conn;
struct l9p_backend *be;
struct l9p_fid *fid;
int error;
/* Xattr fids are not open, so we need our own tests. */
error = fid_lookup(conn, req->lr_req.hdr.fid, EINVAL, 0, &req->lr_fid);
if (error)
return (error);
/*
* Adjust so that writing messages (packing data) starts
* right after the count field in the response.
*
* size[4] + Rread[1] + tag[2] + count[4] = 11
*/
l9p_seek_iov(req->lr_resp_msg.lm_iov, req->lr_resp_msg.lm_niov,
req->lr_data_iov, &req->lr_data_niov, 11);
/*
* If it's an xattr fid there must, by definition, be an
* xattrread. The xattrread function can only be NULL if
* xattrwalk and xattrcreate are NULL or always return error.
*
* TODO:
* separate out directory-read
* allow async read
*/
be = conn->lc_server->ls_backend;
fid = req->lr_fid;
if (l9p_fid_isxattr(fid)) {
error = be->xattrread(be->softc, req);
} else if (l9p_fid_isopen(fid)) {
error = be->read(be->softc, req);
} else {
error = EINVAL;
}
return (error);
}
static int
l9p_dispatch_tremove(struct l9p_request *req)
{
struct l9p_connection *conn = req->lr_conn;
struct l9p_backend *be;
struct l9p_fid *fid;
int error;
/*
* ?? Should we allow Tremove on auth fids? If so, do
* we pretend it is just a Tclunk?
*/
error = fid_lookup(conn, req->lr_req.hdr.fid, EINVAL, 0, &fid);
if (error)
return (error);
be = conn->lc_server->ls_backend;
l9p_fid_unsetvalid(fid);
error = be->remove(be->softc, fid);
/* fid is now gone regardless of any error return */
l9p_connection_remove_fid(conn, fid);
return (error);
}
static int
l9p_dispatch_tstat(struct l9p_request *req)
{
struct l9p_connection *conn = req->lr_conn;
struct l9p_backend *be;
struct l9p_fid *fid;
int error;
/* Allow Tstat on auth fid? Seems harmless enough... */
error = fid_lookup(conn, req->lr_req.hdr.fid, ENOENT,
F_ALLOW_AUTH, &fid);
if (error)
return (error);
be = conn->lc_server->ls_backend;
req->lr_fid = fid;
error = be->stat(be->softc, req);
if (error == 0) {
if (l9p_fid_isauth(fid))
req->lr_resp.rstat.stat.qid.type |= L9P_QTAUTH;
/* should we check req->lr_resp.rstat.qid.type L9P_QTDIR bit? */
if (req->lr_resp.rstat.stat.qid.type &= L9P_QTDIR)
l9p_fid_setdir(fid);
else
l9p_fid_unsetdir(fid);
}
return (error);
}
static int
l9p_dispatch_twalk(struct l9p_request *req)
{
struct l9p_connection *conn = req->lr_conn;
struct l9p_backend *be;
struct l9p_fid *fid, *newfid;
uint16_t n;
int error;
/* Can forbid XATTR, but cannot require DIR. */
error = fid_lookup(conn, req->lr_req.hdr.fid, ENOENT,
F_FORBID_XATTR, &fid);
if (error)
return (error);
if (req->lr_req.twalk.hdr.fid != req->lr_req.twalk.newfid) {
newfid = l9p_connection_alloc_fid(conn,
req->lr_req.twalk.newfid);
if (newfid == NULL)
return (EINVAL);
} else
newfid = fid;
be = conn->lc_server->ls_backend;
req->lr_fid = fid;
req->lr_newfid = newfid;
error = be->walk(be->softc, req);
/*
* If newfid == fid, then fid itself has (potentially) changed,
* but is still valid. Otherwise set newfid valid on
* success, and destroy it on error.
*/
if (newfid != fid) {
if (error == 0)
l9p_fid_setvalid(newfid);
else
l9p_connection_remove_fid(conn, newfid);
}
/*
* If we walked any name elements, the last (n-1'th) qid
* has the type (dir vs file) for the new fid. Otherwise
* the type of newfid is the same as fid. Of course, if
* n==0 and fid==newfid, fid is already set up correctly
* as the whole thing was a big no-op, but it's safe to
* copy its dir bit to itself.
*/
if (error == 0) {
n = req->lr_resp.rwalk.nwqid;
if (n > 0) {
if (req->lr_resp.rwalk.wqid[n - 1].type & L9P_QTDIR)
l9p_fid_setdir(newfid);
} else {
if (l9p_fid_isdir(fid))
l9p_fid_setdir(newfid);
}
}
return (error);
}
static int
l9p_dispatch_twrite(struct l9p_request *req)
{
struct l9p_connection *conn = req->lr_conn;
struct l9p_backend *be;
struct l9p_fid *fid;
int error;
/* Cannot require open due to xattr write, but can forbid dir. */
error = fid_lookup(conn, req->lr_req.hdr.fid, EINVAL,
F_FORBID_DIR, &req->lr_fid);
if (error)
return (error);
/*
* Adjust to point to the data to be written (a la
* l9p_dispatch_tread, but we're pointing into the request
* buffer rather than the response):
*
* size[4] + Twrite[1] + tag[2] + fid[4] + offset[8] + count[4] = 23
*/
l9p_seek_iov(req->lr_req_msg.lm_iov, req->lr_req_msg.lm_niov,
req->lr_data_iov, &req->lr_data_niov, 23);
/*
* Unlike read, write and xattrwrite are optional (for R/O fs).
*
* TODO:
* allow async write
*/
be = conn->lc_server->ls_backend;
fid = req->lr_fid;
if (l9p_fid_isxattr(fid)) {
error = be->xattrwrite != NULL ?
be->xattrwrite(be->softc, req) : ENOSYS;
} else if (l9p_fid_isopen(fid)) {
error = be->write != NULL ?
be->write(be->softc, req) : ENOSYS;
} else {
error = EINVAL;
}
return (error);
}
static int
l9p_dispatch_twstat(struct l9p_request *req)
{
struct l9p_connection *conn = req->lr_conn;
struct l9p_backend *be;
int error;
error = fid_lookup(conn, req->lr_req.hdr.fid, EINVAL,
F_FORBID_XATTR, &req->lr_fid);
if (error)
return (error);
be = conn->lc_server->ls_backend;
error = be->wstat != NULL ? be->wstat(be->softc, req) : ENOSYS;
return (error);
}
static int
l9p_dispatch_tstatfs(struct l9p_request *req)
{
struct l9p_connection *conn = req->lr_conn;
struct l9p_backend *be;
int error;
/* Should we allow statfs on auth fids? */
error = fid_lookup(conn, req->lr_req.hdr.fid, EINVAL, 0, &req->lr_fid);
if (error)
return (error);
be = conn->lc_server->ls_backend;
error = be->statfs(be->softc, req);
return (error);
}
static int
l9p_dispatch_tlopen(struct l9p_request *req)
{
struct l9p_connection *conn = req->lr_conn;
struct l9p_backend *be;
int error;
error = fid_lookup(conn, req->lr_req.hdr.fid, ENOENT,
F_FORBID_OPEN | F_FORBID_XATTR, &req->lr_fid);
if (error)
return (error);