forked from falcosecurity/libs
-
Notifications
You must be signed in to change notification settings - Fork 0
/
ppm_events.c
1795 lines (1582 loc) · 44.6 KB
/
ppm_events.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 (C) 2021 The Falco Authors.
This file is dual licensed under either the MIT or GPL 2. See MIT.txt
or GPL2.txt for full copies of the license.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#ifndef UDIG
#include <linux/compat.h>
#include <linux/kobject.h>
#include <linux/cdev.h>
#include <net/sock.h>
#include <net/af_unix.h>
#include <net/compat.h>
#include <net/ipv6.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/file.h>
#include <linux/fs_struct.h>
#include <linux/uaccess.h>
#include <linux/version.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <asm/mman.h>
#include <linux/in.h>
#if LINUX_VERSION_CODE <= KERNEL_VERSION(2, 6, 20)
#include <linux/mount.h>
#include "ppm_syscall.h"
#else
#include <asm/syscall.h>
#endif
#else // UDIG
#define _GNU_SOURCE
#include <inttypes.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include <stdarg.h>
#include <limits.h>
#include <unistd.h>
#include <sys/mman.h>
#include <signal.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/syscall.h>
#include <time.h>
#include <netinet/in.h>
#include <sys/param.h>
#include <sched.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <poll.h>
#include <sys/sem.h>
#include <sys/file.h>
#include <sys/quota.h>
#include <sys/ptrace.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <errno.h>
#include "udig_capture.h"
#include "ppm_ringbuffer.h"
#include "ppm_events_public.h"
#include "ppm_events.h"
#include "ppm.h"
#include "udig_inf.h"
#endif /* UDIG */
#include "ppm_ringbuffer.h"
#include "ppm_events_public.h"
#include "ppm_events.h"
#include "ppm.h"
#include "ppm_flag_helpers.h"
#include "ppm_version.h"
/*
* The kernel patched with grsecurity makes the default access_ok trigger a
* might_sleep(), so if present we use the one defined by them
*/
#ifndef UDIG
#ifdef access_ok_noprefault
#define ppm_access_ok access_ok_noprefault
#else
#if (LINUX_VERSION_CODE >= KERNEL_VERSION(5, 0, 0)) || (PPM_RHEL_RELEASE_CODE > 0 && PPM_RHEL_RELEASE_CODE >= PPM_RHEL_RELEASE_VERSION(8, 1))
#define ppm_access_ok(type, addr, size) access_ok(addr, size)
#else
#define ppm_access_ok(type, addr, size) access_ok(type, addr, size)
#endif
#endif
extern bool g_tracers_enabled;
static void memory_dump(char *p, size_t size)
{
unsigned int j;
for (j = 0; j < size; j += 8)
pr_info("%*ph\n", 8, &p[j]);
}
#endif // UDIG
static inline bool in_port_range(uint16_t port, uint16_t min, uint16_t max)
{
return port >= min && port <= max;
}
/*
* Globals
*/
u32 g_http_options_intval;
u32 g_http_get_intval;
u32 g_http_head_intval;
u32 g_http_post_intval;
u32 g_http_put_intval;
u32 g_http_delete_intval;
u32 g_http_trace_intval;
u32 g_http_connect_intval;
u32 g_http_resp_intval;
#ifndef UDIG
/*
* What this function does is basically a special memcpy
* so that, if the page fault handler detects the address is invalid,
* won't kill the process but will return a positive number
* Plus, this doesn't sleep.
* The risk is that if the buffer is partially paged out, we get an error.
* Returns the number of bytes NOT read.
*/
unsigned long ppm_copy_from_user(void *to, const void __user *from, unsigned long n)
{
unsigned long res = n;
pagefault_disable();
if (likely(ppm_access_ok(VERIFY_READ, from, n)))
res = __copy_from_user_inatomic(to, from, n);
pagefault_enable();
return res;
}
/*
* On some kernels (e.g. 2.6.39), even with preemption disabled, the strncpy_from_user,
* instead of returning -1 after a page fault, schedules the process, so we drop events
* because of the preemption. This function reads the user buffer in atomic chunks, and
* returns when:
* 1. there's an error (returns `-1`).
* 2. the terminator is found. (the `\0` is computed in the overall length)
* 3. we have read `n` bytes. (in this case, we don't have the `\0` but it's ok we will add it in the caller)
*/
/// TODO: we need to change the return value to `int` and the third param from `unsigned long n` to 'uint32_t n`
long ppm_strncpy_from_user(char *to, const char __user *from, unsigned long n)
{
long string_length = 0;
long res = -1;
unsigned long bytes_to_read = 4;
int j;
pagefault_disable();
while (n) {
/*
* Read bytes_to_read bytes at a time, and look for the terminator. Should be fast
* since the copy_from_user is optimized for the processor
*/
if (n < bytes_to_read)
bytes_to_read = n;
if (!ppm_access_ok(VERIFY_READ, from, bytes_to_read)) {
res = -1;
goto strncpy_end;
}
if (__copy_from_user_inatomic(to, from, bytes_to_read)) {
/*
* Page fault
*/
res = -1;
goto strncpy_end;
}
n -= bytes_to_read;
from += bytes_to_read;
for (j = 0; j < bytes_to_read; ++j) {
++string_length;
/* Check if `*to` is the `\0`. */
if (!*to) {
res = string_length;
goto strncpy_end;
}
++to;
}
}
/* We read all the `n` bytes. */
res = string_length;
strncpy_end:
pagefault_enable();
return res;
}
#endif
int32_t dpi_lookahead_init(void)
{
g_http_options_intval = (*(u32 *)HTTP_OPTIONS_STR);
g_http_get_intval = (*(u32 *)HTTP_GET_STR);
g_http_head_intval = (*(u32 *)HTTP_HEAD_STR);
g_http_post_intval = (*(u32 *)HTTP_POST_STR);
g_http_put_intval = (*(u32 *)HTTP_PUT_STR);
g_http_delete_intval = (*(u32 *)HTTP_DELETE_STR);
g_http_trace_intval = (*(u32 *)HTTP_TRACE_STR);
g_http_connect_intval = (*(u32 *)HTTP_CONNECT_STR);
g_http_resp_intval = (*(u32 *)HTTP_RESP_STR);
return PPM_SUCCESS;
}
#ifndef UDIG
inline int sock_getname(struct socket* sock, struct sockaddr* sock_address, int peer)
{
#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 8, 0)
/*
* Avoid calling sock->ops->getname(), because in certain kernel versions,
* the getname functions may take a lock, which violates the limitations of
* the RCU lock execution environment which is used by the kernel module.
*
* An example is the usage of `BPF_CGROUP_RUN_SA_PROG_LOCK` since kernel version `5.8.0`
* https://elixir.bootlin.com/linux/v5.8/source/net/ipv4/af_inet.c#L785
*
* For efficiency, only fill in sockaddr fields actually used by the
* kernel module logic; in particular, skip filling in
* - sin_zero
* - sin6_scope_id
* - sin6_flowinfo
*/
struct sock *sk = sock->sk;
switch(sk->sk_family) {
case AF_INET:
{
struct sockaddr_in *sin = (struct sockaddr_in *)sock_address;
struct inet_sock *inet = (struct inet_sock *)sk;
sin->sin_family = AF_INET;
if (peer) {
if (!inet->inet_dport ||
((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT))) {
return -ENOTCONN;
}
sin->sin_port = inet->inet_dport;
sin->sin_addr.s_addr = inet->inet_daddr;
} else {
u32 addr = inet->inet_rcv_saddr;
if (!addr) {
addr = inet->inet_saddr;
}
sin->sin_port = inet->inet_sport;
sin->sin_addr.s_addr = addr;
}
break;
}
case AF_INET6:
{
struct sockaddr_in6 *sin = (struct sockaddr_in6 *)sock_address;
struct inet_sock *inet = (struct inet_sock *)sk;
struct ipv6_pinfo *np = (struct ipv6_pinfo *)inet->pinet6;
sin->sin6_family = AF_INET6;
if (peer) {
if ((!inet->inet_dport) ||
((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT))) {
return -ENOTCONN;
}
sin->sin6_port = inet->inet_dport;
sin->sin6_addr = sk->sk_v6_daddr;
} else {
sin->sin6_addr = sk->sk_v6_rcv_saddr;
if (ipv6_addr_any(&sin->sin6_addr)) {
sin->sin6_addr = np->saddr;
}
sin->sin6_port = inet->inet_sport;
}
break;
}
case AF_UNIX:
{
struct sockaddr_un *sunaddr = (struct sockaddr_un *)sock_address;
struct unix_sock *u;
struct unix_address *u_addr = NULL;
if (peer) {
sk = ((struct unix_sock *)sk)->peer;
if (!sk) {
return -ENOTCONN;
}
}
u = (struct unix_sock *)sk;
u_addr = u->addr;
if (!u_addr) {
sunaddr->sun_family = AF_UNIX;
sunaddr->sun_path[0] = 0;
} else {
unsigned int len = u_addr->len;
if (unlikely(len > sizeof(struct sockaddr_storage))) {
len = sizeof(struct sockaddr_storage);
}
memcpy(sunaddr, u_addr->name, len);
}
break;
}
default:
return -ENOTCONN;
}
return 0;
#elif LINUX_VERSION_CODE >= KERNEL_VERSION(4, 17, 0)
int ret = sock->ops->getname(sock, sock_address, peer);
if (ret >= 0)
ret = 0;
return ret;
#else
int sockaddr_len;
return sock->ops->getname(sock, sock_address, &sockaddr_len, peer);
#endif
}
/**
* Compute the snaplen for the arguments.
*
* The snaplen is the amount of argument data returned along with the event.
* Normally, the driver performs a dynamic calculation to figure out snaplen
* per-event. However, if this calculation is disabled
* (i.e. args->consumer->do_dynamic_snaplen == false), the snaplen will always
* be args->consumer->snaplen.
*
* If dynamic snaplen is enabled, here's how the calculation works:
*
* 1. If the event is a write to /dev/null, it gets a special snaplen because
* writes to /dev/null is a backdoor method for inserting special events
* into the event stream.
* 2. If the event is NOT a socket operation, return args->consumer->snaplen.
* 3. If the sending port OR destination port falls within the fullcapture port
* range specified by the user, return 16000.
* 4. Protocol detection. A number of applications are detected heuristically
* and given a longer snaplen (2000). These applications are MYSQL, Postgres,
* HTTP, mongodb, and statsd.
* 5. If none of the above apply, return args->consumer->snaplen.
*/
inline u32 compute_snaplen(struct event_filler_arguments *args, char *buf, u32 lookahead_size)
{
u32 res = args->consumer->snaplen;
int err;
struct socket *sock;
sa_family_t family;
struct sockaddr_storage sock_address;
struct sockaddr_storage peer_address;
u16 sport, dport;
u16 min_port = 0, max_port = 0;
u32 dynamic_snaplen = SNAPLEN_EXTENDED;
if (args->consumer->snaplen > dynamic_snaplen) {
/*
* If the user requested a default snaplen greater than the custom
* snaplen given to certain applications, just use the greater value.
*/
dynamic_snaplen = args->consumer->snaplen;
}
/* Increase snaplen on writes to /dev/null */
if (g_tracers_enabled && args->event_type == PPME_SYSCALL_WRITE_X) {
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 14, 0)
struct fd f = fdget(args->fd);
if (f.file && f.file->f_inode) {
if (f.file->f_inode->i_rdev == PPM_NULL_RDEV) {
res = SNAPLEN_TRACERS_ENABLED;
fdput(f);
return res;
}
fdput(f);
}
#else
struct file* file = fget(args->fd);
/* Use cached f_inode only on kernel versions that have it
* https://github.com/torvalds/linux/commit/dd37978c50bc8b354e5c4633f69387f16572fdac
*/
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 9, 0)
if (file && file->f_inode) {
if (file->f_inode->i_rdev == PPM_NULL_RDEV) {
// Use f_dentry for older kernel versions
#elif LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,20)
if (file && file->f_dentry && file->f_dentry->d_inode) {
if (file->f_dentry->d_inode->i_rdev == PPM_NULL_RDEV) {
#else
if (file && file->f_path.dentry && file->f_path.dentry->d_inode) {
if (file->f_path.dentry->d_inode->i_rdev == PPM_NULL_RDEV) {
#endif
res = SNAPLEN_TRACERS_ENABLED;
fput(file);
return res;
}
fput(file);
}
#endif
}
if (!args->consumer->do_dynamic_snaplen)
return res;
sock = sockfd_lookup(args->fd, &err);
if (!sock) {
return res;
}
if (!sock->sk) {
goto done;
}
err = sock_getname(sock, (struct sockaddr *)&sock_address, 0);
if (err != 0) {
goto done;
}
/* Try to get the source and destination port */
if (args->event_type == PPME_SOCKET_SENDTO_X) {
unsigned long val;
struct sockaddr __user * usrsockaddr;
/*
* Get the address
*/
val = args->args[4];
usrsockaddr = (struct sockaddr __user *)val;
if(usrsockaddr == NULL) {
/*
* Suppose is a connected socket, fall back to fd
*/
err = sock_getname(sock, (struct sockaddr *)&peer_address, 1);
} else {
/*
* Get the address len
*/
val = args->args[5];
if (val != 0) {
/*
* Copy the address
*/
err = addr_to_kernel(usrsockaddr, val, (struct sockaddr *)&peer_address);
} else {
/*
* This case should be very rare, fallback again to sock
*/
err = sock_getname(sock, (struct sockaddr *)&peer_address, 1);
}
}
} else if (args->event_type == PPME_SOCKET_SENDMSG_X) {
unsigned long val;
struct sockaddr __user * usrsockaddr;
int addrlen;
#ifdef CONFIG_COMPAT
struct compat_msghdr compat_mh;
#endif
#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 19, 0)
struct user_msghdr mh;
#else
struct msghdr mh;
#endif
val = args->args[1];
#ifdef CONFIG_COMPAT
if (!args->compat) {
#endif
if (unlikely(ppm_copy_from_user(&mh, (const void __user *)val, sizeof(mh)))) {
usrsockaddr = NULL;
addrlen = 0;
} else {
usrsockaddr = (struct sockaddr __user *)mh.msg_name;
addrlen = mh.msg_namelen;
}
#ifdef CONFIG_COMPAT
} else {
if (unlikely(ppm_copy_from_user(&compat_mh, (const void __user *)compat_ptr(val), sizeof(compat_mh)))) {
usrsockaddr = NULL;
addrlen = 0;
} else {
usrsockaddr = (struct sockaddr __user *)compat_ptr(compat_mh.msg_name);
addrlen = compat_mh.msg_namelen;
}
}
#endif
if (usrsockaddr != NULL && addrlen != 0) {
/*
* Copy the address
*/
err = addr_to_kernel(usrsockaddr, addrlen, (struct sockaddr *)&peer_address);
} else {
/*
* Suppose it is a connected socket, fall back to fd
*/
err = sock_getname(sock, (struct sockaddr *)&peer_address, 1);
}
} else {
err = sock_getname(sock, (struct sockaddr *)&peer_address, 1);
}
if (err != 0) {
goto done;
}
/*
* If there's a valid source / dest port, use it to run heuristics
* for determining snaplen.
*/
min_port = args->consumer->fullcapture_port_range_start;
max_port = args->consumer->fullcapture_port_range_end;
family = sock->sk->sk_family;
if (family == AF_INET) {
sport = ntohs(((struct sockaddr_in *) &sock_address)->sin_port);
dport = ntohs(((struct sockaddr_in *) &peer_address)->sin_port);
} else if (family == AF_INET6) {
sport = ntohs(((struct sockaddr_in6 *) &sock_address)->sin6_port);
dport = ntohs(((struct sockaddr_in6 *) &peer_address)->sin6_port);
} else {
sport = 0;
dport = 0;
}
if (max_port > 0 &&
(in_port_range(sport, min_port, max_port) ||
in_port_range(dport, min_port, max_port))) {
/*
* Before checking the well-known ports, see if the user has requested
* an increased snaplen for the port in question.
*/
sockfd_put(sock);
return SNAPLEN_FULLCAPTURE_PORT;
} else if (sport == PPM_PORT_MYSQL || dport == PPM_PORT_MYSQL) {
if (lookahead_size >= 5) {
if (buf[0] == 3 || buf[1] == 3 || buf[2] == 3 || buf[3] == 3 || buf[4] == 3) {
res = dynamic_snaplen;
goto done;
} else if (buf[2] == 0 && buf[3] == 0) {
res = dynamic_snaplen;
goto done;
}
}
} else if (sport == PPM_PORT_POSTGRES || dport == PPM_PORT_POSTGRES) {
if (lookahead_size >= 2) {
if ((buf[0] == 'Q' && buf[1] == 0) || /* SimpleQuery command */
(buf[0] == 'P' && buf[1] == 0) || /* Prepare statement command */
(buf[0] == 'E' && buf[1] == 0) /* error or execute command */
) {
res = dynamic_snaplen;
goto done;
}
}
if (lookahead_size >= 7 &&
(buf[4] == 0 && buf[5] == 3 && buf[6] == 0)) { /* startup command */
res = dynamic_snaplen;
goto done;
}
} else if ((sport == PPM_PORT_MONGODB || dport == PPM_PORT_MONGODB) ||
(lookahead_size >= 16 &&
(*(int32_t *)(buf+12) == 1 || /* matches header */
*(int32_t *)(buf+12) == 2001 ||
*(int32_t *)(buf+12) == 2002 ||
*(int32_t *)(buf+12) == 2003 ||
*(int32_t *)(buf+12) == 2004 ||
*(int32_t *)(buf+12) == 2005 ||
*(int32_t *)(buf+12) == 2006 ||
*(int32_t *)(buf+12) == 2007)
)
) {
res = dynamic_snaplen;
goto done;
} else if (dport == args->consumer->statsd_port) {
res = dynamic_snaplen;
goto done;
} else {
if (lookahead_size >= 5) {
if (*(u32 *)buf == g_http_get_intval ||
*(u32 *)buf == g_http_post_intval ||
*(u32 *)buf == g_http_put_intval ||
*(u32 *)buf == g_http_delete_intval ||
*(u32 *)buf == g_http_trace_intval ||
*(u32 *)buf == g_http_connect_intval ||
*(u32 *)buf == g_http_options_intval ||
((*(u32 *)buf == g_http_resp_intval) && (buf[4] == '/'))
) {
res = dynamic_snaplen;
goto done;
}
}
}
done:
sockfd_put(sock);
return res;
}
#endif // UDIG
int push_empty_param(struct event_filler_arguments *args)
{
u16 *psize = (u16 *)(args->buffer + args->curarg * sizeof(u16));
if (unlikely(args->curarg >= args->nargs))
{
#ifndef UDIG
pr_err("(%u)val_to_ring: too many arguments for event #%u, type=%u, curarg=%u, nargs=%u tid:%u\n",
smp_processor_id(),
args->nevents,
(u32)args->event_type,
args->curarg,
args->nargs,
current->pid);
memory_dump(args->buffer - sizeof(struct ppm_evt_hdr), 32);
#endif
ASSERT(0);
return PPM_FAILURE_BUG;
}
/* We push 0 in the length array */
*psize = 0;
/* We increment the current argument */
args->curarg++;
return PPM_SUCCESS;
}
/*
* NOTES:
* - val_len is ignored for everything other than PT_BYTEBUF.
* - fromuser is ignored for numeric types
* - dyn_idx is ignored for everything other than PT_DYN
*/
int val_to_ring(struct event_filler_arguments *args, uint64_t val, u32 val_len, bool fromuser, u8 dyn_idx)
{
const struct ppm_param_info *param_info;
int len = -1;
u16 *psize = (u16 *)(args->buffer + args->curarg * sizeof(u16));
u32 max_arg_size = args->arg_data_size;
if (unlikely(args->curarg >= args->nargs)) {
#ifndef UDIG
pr_err("(%u)val_to_ring: too many arguments for event #%u, type=%u, curarg=%u, nargs=%u tid:%u\n",
smp_processor_id(),
args->nevents,
(u32)args->event_type,
args->curarg,
args->nargs,
current->pid);
memory_dump(args->buffer - sizeof(struct ppm_evt_hdr), 32);
#endif
ASSERT(0);
return PPM_FAILURE_BUG;
}
if (unlikely(args->arg_data_size == 0))
return PPM_FAILURE_BUFFER_FULL;
if (max_arg_size > PPM_MAX_ARG_SIZE)
max_arg_size = PPM_MAX_ARG_SIZE;
param_info = &(g_event_info[args->event_type].params[args->curarg]);
if (param_info->type == PT_DYN && param_info->info != NULL) {
const struct ppm_param_info *dyn_params;
if (unlikely(dyn_idx >= param_info->ninfo)) {
ASSERT(0);
return PPM_FAILURE_BUG;
}
#if defined(UDIG)
dyn_params = (const struct ppm_param_info *)patch_pointer((uint8_t*)param_info->info);
#else
dyn_params = (const struct ppm_param_info *)param_info->info;
#endif
param_info = &dyn_params[dyn_idx];
if (likely(max_arg_size >= sizeof(u8))) {
*(u8 *)(args->buffer + args->arg_data_offset) = dyn_idx;
len = sizeof(u8);
} else {
return PPM_FAILURE_BUFFER_FULL;
}
args->arg_data_offset += len;
args->arg_data_size -= len;
max_arg_size -= len;
*psize = (u16)len;
} else {
*psize = 0;
}
switch (param_info->type) {
case PT_CHARBUF:
case PT_FSPATH:
case PT_FSRELPATH:
if(unlikely(val == 0))
{
/* Send an empty param when we have a null pointer `val==0` */
len = 0;
break;
}
if(fromuser)
{
len = ppm_strncpy_from_user(args->buffer + args->arg_data_offset,
(const char __user *)(syscall_arg_t)val, max_arg_size);
if(unlikely(len < 0))
{
len = 0;
break;
}
/* Two possible cases here:
*
* 1. `len < max_arg_size`, the terminator is always there, and `len` takes it into account,
* so we need to do nothing. We just push a `\0` to an empty byte to avoid an if
* case.
*
* 2. `len == max_arg_size`, the terminator is not there but we cannot push an additional
* char for this reason we overwrite the last char and we don't increment `len`.
*/
*(char *)(args->buffer + args->arg_data_offset + max_arg_size - 1) = '\0';
}
else
{
len = (int)strlcpy(args->buffer + args->arg_data_offset,
(const char *)(syscall_arg_t)val,
max_arg_size);
/* WARNING: `strlcpy` returns the length of the string it tries to create
* so `len` could also be greater than `max_arg_size`, but please note that the copied
* charbuf is at max `max_arg_size` (where the last byte is used for the `\0`).
* The copied string is always `\0` terminated but the returned `len` doesn't
* take into consideration the `\0` like `strlen()` function.
*
* Two possible cases here:
*
* 1. `len < max_arg_size`, the terminator is always there, but `len` doesn't take it into account,
* so we need to increment the `len`. Note that if the source string has exactly `max_arg_size`
* characters the returned `len` is `max_arg_size-1` so we need to do `len++` to obtain the copied size.
*
* 2. `len >= max_arg_size`, the source string is greater than `max_arg_size`. `strlcpy` copied
* `max_arg_size - 1` and added the `\0` at the end, so our final copied `len` is `max_arg_size` we have just
* to resize it and we have done.
*/
if(++len >= max_arg_size)
{
len = max_arg_size;
}
}
break;
case PT_BYTEBUF:
if (likely(val != 0 && val_len)) {
if (fromuser)
{
/*
* Copy the lookahead portion of the buffer that we will use DPI-based
* snaplen calculation
*/
u32 dpi_lookahead_size = DPI_LOOKAHEAD_SIZE;
if (dpi_lookahead_size > val_len)
dpi_lookahead_size = val_len;
if (unlikely(dpi_lookahead_size >= max_arg_size))
return PPM_FAILURE_BUFFER_FULL;
/* Returns the number of bytes NOT read. */
len = (int)ppm_copy_from_user(args->buffer + args->arg_data_offset,
(const void __user *)(syscall_arg_t)val,
dpi_lookahead_size);
if(unlikely(len != 0))
{
goto send_empty_bytebuf_param;
}
/*
* Check if there's more to copy
*/
if (likely((dpi_lookahead_size != val_len))) {
/*
* Calculate the snaplen
*/
if (likely(args->enforce_snaplen)) {
u32 sl = args->consumer->snaplen;
#ifndef UDIG
sl = compute_snaplen(args, args->buffer + args->arg_data_offset, dpi_lookahead_size);
#endif
if (val_len > sl)
val_len = sl;
}
if (unlikely((val_len) >= max_arg_size))
val_len = max_arg_size;
if (val_len > dpi_lookahead_size) {
len = (int)ppm_copy_from_user(args->buffer + args->arg_data_offset + dpi_lookahead_size,
(const uint8_t __user *)(syscall_arg_t)val + dpi_lookahead_size,
val_len - dpi_lookahead_size);
if (unlikely(len != 0))
{
goto send_empty_bytebuf_param;
}
}
}
len = val_len;
}
else
{
if (likely(args->enforce_snaplen)) {
#ifdef UDIG
u32 sl = args->consumer->snaplen;
#else
u32 sl = compute_snaplen(args, (char *)(syscall_arg_t)val, val_len);
#endif
if (val_len > sl)
val_len = sl;
}
if (unlikely(val_len >= max_arg_size))
return PPM_FAILURE_BUFFER_FULL;
memcpy(args->buffer + args->arg_data_offset,
(void *)(syscall_arg_t)val, val_len);
len = val_len;
}
/* If we arrive here we have something to send. */
break;
}
/* Send an empty param in all these cases:
* - we have a null pointer `val==0` or `val_len==0`.
* - we have read `0` bytes.
* - we faced an error while reading.
*/
send_empty_bytebuf_param:
len = 0;
break;
case PT_SOCKADDR:
case PT_SOCKTUPLE:
case PT_FDLIST:
if(likely(val != 0))
{
if (unlikely(val_len >= max_arg_size))
return PPM_FAILURE_BUFFER_FULL;
if(fromuser)
{
len = (int)ppm_copy_from_user(args->buffer + args->arg_data_offset,
(const void __user *)(syscall_arg_t)val,
val_len);
if(unlikely(len != 0))
{
goto send_empty_sock_param;
}
len = val_len;
}
else
{
memcpy(args->buffer + args->arg_data_offset,
(void *)(syscall_arg_t)val, val_len);
len = val_len;
}
/* If we arrive here we have something to send. */
break;
}
send_empty_sock_param:
len = 0;
break;
case PT_FLAGS8:
case PT_ENUMFLAGS8:
case PT_UINT8:
case PT_SIGTYPE:
if (likely(max_arg_size >= sizeof(u8))) {
*(u8 *)(args->buffer + args->arg_data_offset) = (u8)val;
len = sizeof(u8);
} else {
return PPM_FAILURE_BUFFER_FULL;
}
break;
case PT_FLAGS16:
case PT_ENUMFLAGS16:
case PT_UINT16:
case PT_SYSCALLID:
if (likely(max_arg_size >= sizeof(u16))) {
*(u16 *)(args->buffer + args->arg_data_offset) = (u16)val;
len = sizeof(u16);
} else {
return PPM_FAILURE_BUFFER_FULL;
}
break;
case PT_FLAGS32:
case PT_UINT32:
case PT_MODE:
case PT_UID:
case PT_GID:
case PT_SIGSET:
case PT_ENUMFLAGS32:
if (likely(max_arg_size >= sizeof(u32))) {
*(u32 *)(args->buffer + args->arg_data_offset) = (u32)val;
len = sizeof(u32);
} else {
return PPM_FAILURE_BUFFER_FULL;
}
break;
case PT_RELTIME:
case PT_ABSTIME:
case PT_UINT64:
if (likely(max_arg_size >= sizeof(u64))) {
*(u64 *)(args->buffer + args->arg_data_offset) = (u64)val;
len = sizeof(u64);
} else {
return PPM_FAILURE_BUFFER_FULL;
}
break;
case PT_INT8:
if (likely(max_arg_size >= sizeof(s8))) {
*(s8 *)(args->buffer + args->arg_data_offset) = (s8)(long)val;
len = sizeof(s8);
} else {
return PPM_FAILURE_BUFFER_FULL;
}
break;
case PT_INT16:
if (likely(max_arg_size >= sizeof(s16))) {
*(s16 *)(args->buffer + args->arg_data_offset) = (s16)(long)val;
len = sizeof(s16);
} else {
return PPM_FAILURE_BUFFER_FULL;
}
break;
case PT_INT32:
if (likely(max_arg_size >= sizeof(s32))) {
*(s32 *)(args->buffer + args->arg_data_offset) = (s32)(long)val;
len = sizeof(s32);
} else {
return PPM_FAILURE_BUFFER_FULL;
}
break;
case PT_INT64:
case PT_ERRNO:
case PT_FD:
case PT_PID:
if (likely(max_arg_size >= sizeof(s64))) {
*(s64 *)(args->buffer + args->arg_data_offset) = (s64)(long)val;
len = sizeof(s64);
} else {
return PPM_FAILURE_BUFFER_FULL;
}
break;
default:
ASSERT(0);
#ifndef UDIG
pr_err("val_to_ring: invalid argument type %d. Event %u (%s) might have less parameters than what has been declared in nparams\n",
(int)g_event_info[args->event_type].params[args->curarg].type,