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
|
/* $OpenBSD: monitor.c,v 1.54 2005/05/27 19:26:25 cloder Exp $ */
/*
* Copyright (c) 2003 Håkan Olsson. 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.
*
* 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 <sys/param.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <netinet/in.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <pwd.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <regex.h>
#include <keynote.h>
#include "conf.h"
#include "log.h"
#include "monitor.h"
#include "policy.h"
#include "ui.h"
#include "util.h"
#include "pf_key_v2.h"
struct monitor_state {
pid_t pid;
int s;
char root[MAXPATHLEN];
} m_state;
volatile sig_atomic_t sigchlded = 0;
extern volatile sig_atomic_t sigtermed;
static volatile sig_atomic_t cur_state = STATE_INIT;
extern void set_slave_signals(void);
/* Private functions. */
static void must_read(void *, size_t);
static void must_write(const void *, size_t);
static void m_priv_getfd(void);
static void m_priv_setsockopt(void);
static void m_priv_bind(void);
static void m_priv_ui_init(void);
static void m_priv_pfkey_open(void);
static int m_priv_local_sanitize_path(char *, size_t, int);
static int m_priv_check_sockopt(int, int);
static int m_priv_check_bind(const struct sockaddr *, socklen_t);
static void m_priv_increase_state(int);
static void m_priv_test_state(int);
static void set_monitor_signals(void);
static void monitor_got_sigchld(int);
static void sig_pass_to_chld(int);
/*
* Public functions, unprivileged.
*/
/* Setup monitor context, fork, drop child privs. */
pid_t
monitor_init(int debug)
{
struct passwd *pw;
int p[2];
bzero(&m_state, sizeof m_state);
if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, p) != 0)
log_fatal("monitor_init: socketpair() failed");
pw = getpwnam(ISAKMPD_PRIVSEP_USER);
if (pw == NULL)
log_fatalx("monitor_init: getpwnam(\"%s\") failed",
ISAKMPD_PRIVSEP_USER);
strlcpy(m_state.root, pw->pw_dir, sizeof m_state.root);
set_monitor_signals();
m_state.pid = fork();
if (m_state.pid == -1)
log_fatal("monitor_init: fork of unprivileged child failed");
if (m_state.pid == 0) {
/* The child process drops privileges. */
set_slave_signals();
if (chroot(pw->pw_dir) != 0 || chdir("/") != 0)
log_fatal("monitor_init: chroot failed");
if (setgroups(1, &pw->pw_gid) == -1 ||
setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) ||
setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid))
log_fatal("monitor_init: can't drop privileges");
m_state.s = p[0];
close(p[1]);
LOG_DBG((LOG_MISC, 10,
"monitor_init: privileges dropped for child process"));
} else {
/* Privileged monitor. */
setproctitle("monitor [priv]");
m_state.s = p[1];
close(p[0]);
}
/* With "-dd", stop and wait here. For gdb "attach" etc. */
if (debug > 1) {
log_print("monitor_init: stopped %s PID %d fd %d%s",
m_state.pid ? "priv" : "child", getpid(), m_state.s,
m_state.pid ? ", waiting for SIGCONT" : "");
kill(getpid(), SIGSTOP); /* Wait here for SIGCONT. */
if (m_state.pid)
kill(m_state.pid, SIGCONT); /* Continue child. */
}
return m_state.pid;
}
void
monitor_exit(int code)
{
if (m_state.pid != 0)
kill(m_state.pid, SIGKILL);
close(m_state.s);
exit(code);
}
void
monitor_ui_init(void)
{
int err, cmd;
cmd = MONITOR_UI_INIT;
must_write(&cmd, sizeof cmd);
must_read(&err, sizeof err);
if (err != 0)
log_fatal("monitor_ui_init: parent could not create FIFO "
"\"%s\"", ui_fifo);
ui_socket = mm_receive_fd(m_state.s);
if (ui_socket < 0)
log_fatal("monitor_ui_init: parent could not create FIFO "
"\"%s\"", ui_fifo);
return;
}
int
monitor_pf_key_v2_open(void)
{
int err, cmd;
cmd = MONITOR_PFKEY_OPEN;
must_write(&cmd, sizeof cmd);
must_read(&err, sizeof err);
if (err < 0) {
log_error("monitor_pf_key_v2_open: parent could not create "
"PF_KEY socket");
return -1;
}
pf_key_v2_socket = mm_receive_fd(m_state.s);
if (pf_key_v2_socket < 0) {
log_error("monitor_pf_key_v2_open: mm_receive_fd() failed: %s",
strerror(errno));
return -1;
}
return pf_key_v2_socket;
}
int
monitor_open(const char *path, int flags, mode_t mode)
{
int fd, err, cmd, len;
char pathreal[MAXPATHLEN];
if (path[0] == '/')
strlcpy(pathreal, path, sizeof pathreal);
else
snprintf(pathreal, sizeof pathreal, "%s/%s", m_state.root,
path);
cmd = MONITOR_GET_FD;
must_write(&cmd, sizeof cmd);
len = strlen(pathreal);
must_write(&len, sizeof len);
must_write(&pathreal, len);
must_write(&flags, sizeof flags);
must_write(&mode, sizeof mode);
must_read(&err, sizeof err);
if (err != 0) {
errno = err;
return -1;
}
fd = mm_receive_fd(m_state.s);
if (fd < 0) {
log_error("monitor_open: mm_receive_fd () failed: %s",
strerror(errno));
return -1;
}
return fd;
}
FILE *
monitor_fopen(const char *path, const char *mode)
{
FILE *fp;
int fd, flags = 0, saved_errno;
mode_t mask, cur_umask;
/* Only the child process is supposed to run this. */
if (m_state.pid)
log_fatal("[priv] bad call to monitor_fopen");
switch (mode[0]) {
case 'r':
flags = (mode[1] == '+' ? O_RDWR : O_RDONLY);
break;
case 'w':
flags = (mode[1] == '+' ? O_RDWR : O_WRONLY) | O_CREAT |
O_TRUNC;
break;
case 'a':
flags = (mode[1] == '+' ? O_RDWR : O_WRONLY) | O_CREAT |
O_APPEND;
break;
default:
log_fatal("monitor_fopen: bad call");
}
cur_umask = umask(0);
(void)umask(cur_umask);
mask = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH;
mask &= ~cur_umask;
fd = monitor_open(path, flags, mask);
if (fd < 0)
return NULL;
/* Got the fd, attach a FILE * to it. */
fp = fdopen(fd, mode);
if (!fp) {
log_error("monitor_fopen: fdopen() failed");
saved_errno = errno;
close(fd);
errno = saved_errno;
return NULL;
}
return fp;
}
int
monitor_stat(const char *path, struct stat *sb)
{
int fd, r, saved_errno;
/* O_NONBLOCK is needed for stat'ing fifos. */
fd = monitor_open(path, O_RDONLY | O_NONBLOCK, 0);
if (fd < 0)
return -1;
r = fstat(fd, sb);
saved_errno = errno;
close(fd);
errno = saved_errno;
return r;
}
int
monitor_setsockopt(int s, int level, int optname, const void *optval,
socklen_t optlen)
{
int ret, err, cmd;
cmd = MONITOR_SETSOCKOPT;
must_write(&cmd, sizeof cmd);
if (mm_send_fd(m_state.s, s))
goto errout;
must_write(&level, sizeof level);
must_write(&optname, sizeof optname);
must_write(&optlen, sizeof optlen);
must_write(optval, (size_t)optlen);
must_read(&err, sizeof err);
must_read(&ret, sizeof ret);
if (err != 0)
errno = err;
return ret;
errout:
log_print("monitor_setsockopt: read/write error");
return -1;
}
int
monitor_bind(int s, const struct sockaddr *name, socklen_t namelen)
{
int ret, err, cmd;
cmd = MONITOR_BIND;
must_write(&cmd, sizeof cmd);
if (mm_send_fd(m_state.s, s))
goto errout;
must_write(&namelen, sizeof namelen);
must_write(name, (size_t)namelen);
must_read(&err, sizeof err);
must_read(&ret, sizeof ret);
if (err != 0)
errno = err;
return ret;
errout:
log_print("monitor_bind: read/write error");
return -1;
}
struct monitor_dirents *
monitor_opendir(const char *path)
{
char *buf, *cp;
size_t bufsize;
int fd, nbytes, entries;
long base;
struct stat sb;
struct dirent *dp;
struct monitor_dirents *direntries;
fd = monitor_open(path, 0, O_RDONLY);
if (fd < 0) {
log_error("monitor_opendir: opendir(\"%s\") failed", path);
return NULL;
}
/* Now build a list with all dirents from fd. */
if (fstat(fd, &sb) < 0) {
(void)close(fd);
return NULL;
}
if (!S_ISDIR(sb.st_mode)) {
(void)close(fd);
errno = EACCES;
return NULL;
}
bufsize = sb.st_size;
if (bufsize < sb.st_blksize)
bufsize = sb.st_blksize;
buf = calloc(bufsize, sizeof(char));
if (buf == NULL) {
(void)close(fd);
errno = EACCES;
return NULL;
}
nbytes = getdirentries(fd, buf, bufsize, &base);
if (nbytes <= 0) {
(void)close(fd);
free(buf);
errno = EACCES;
return NULL;
}
(void)close(fd);
for (entries = 0, cp = buf; cp < buf + nbytes;) {
dp = (struct dirent *)cp;
cp += dp->d_reclen;
entries++;
}
direntries = calloc(1, sizeof(struct monitor_dirents));
if (direntries == NULL) {
free(buf);
errno = EACCES;
return NULL;
}
direntries->dirents = calloc(entries + 1, sizeof(struct dirent *));
if (direntries->dirents == NULL) {
free(buf);
free(direntries);
errno = EACCES;
return NULL;
}
direntries->current = 0;
for (entries = 0, cp = buf; cp < buf + nbytes;) {
dp = (struct dirent *)cp;
direntries->dirents[entries++] = dp;
cp += dp->d_reclen;
}
direntries->dirents[entries] = NULL;
return direntries;
}
struct dirent *
monitor_readdir(struct monitor_dirents *direntries)
{
if (direntries->dirents[direntries->current] != NULL)
return direntries->dirents[direntries->current++];
return NULL;
}
void
monitor_closedir(struct monitor_dirents *direntries)
{
free(direntries->dirents);
free(direntries);
}
void
monitor_init_done(void)
{
int cmd;
cmd = MONITOR_INIT_DONE;
must_write(&cmd, sizeof cmd);
}
/*
* Start of code running with privileges (the monitor process).
*/
static void
set_monitor_signals(void)
{
int n;
for (n = 0; n < _NSIG; n++)
signal(n, SIG_DFL);
/* If the child dies, we should shutdown also. */
signal(SIGCHLD, monitor_got_sigchld);
/* Forward some signals to the child. */
signal(SIGTERM, sig_pass_to_chld);
signal(SIGHUP, sig_pass_to_chld);
signal(SIGUSR1, sig_pass_to_chld);
}
/* ARGSUSED */
static void
monitor_got_sigchld(int sig)
{
sigchlded = 1;
}
static void
sig_pass_to_chld(int sig)
{
int oerrno = errno;
if (m_state.pid > 0)
kill(m_state.pid, sig);
errno = oerrno;
}
/* This function is where the privileged process waits(loops) indefinitely. */
void
monitor_loop(int debug)
{
pid_t pid;
int msgcode, status;
if (!debug)
log_to(0);
while (cur_state < STATE_QUIT) {
/*
* Currently, there is no need for us to hang around if the
* child is in the process of shutting down.
*/
if (sigtermed) {
m_priv_increase_state(STATE_QUIT);
kill(m_state.pid, SIGTERM);
break;
}
if (sigchlded) {
do {
pid = waitpid(m_state.pid, &status, WNOHANG);
} while (pid == -1 && errno == EINTR);
if (pid == m_state.pid && (WIFEXITED(status) ||
WIFSIGNALED(status))) {
m_priv_increase_state(STATE_QUIT);
break;
}
}
must_read(&msgcode, sizeof msgcode);
switch (msgcode) {
case MONITOR_GET_FD:
m_priv_getfd();
break;
case MONITOR_UI_INIT:
LOG_DBG((LOG_MISC, 80,
"monitor_loop: MONITOR_UI_INIT"));
m_priv_test_state(STATE_INIT);
m_priv_ui_init();
break;
case MONITOR_PFKEY_OPEN:
LOG_DBG((LOG_MISC, 80,
"monitor_loop: MONITOR_PFKEY_OPEN"));
m_priv_test_state(STATE_INIT);
m_priv_pfkey_open();
break;
case MONITOR_SETSOCKOPT:
LOG_DBG((LOG_MISC, 80,
"monitor_loop: MONITOR_SETSOCKOPT"));
m_priv_test_state(STATE_INIT);
m_priv_setsockopt();
break;
case MONITOR_BIND:
LOG_DBG((LOG_MISC, 80,
"monitor_loop: MONITOR_BIND"));
m_priv_test_state(STATE_INIT);
m_priv_bind();
break;
case MONITOR_INIT_DONE:
LOG_DBG((LOG_MISC, 80,
"monitor_loop: MONITOR_INIT_DONE"));
m_priv_test_state(STATE_INIT);
m_priv_increase_state(STATE_RUNNING);
break;
case MONITOR_SHUTDOWN:
LOG_DBG((LOG_MISC, 80,
"monitor_loop: MONITOR_SHUTDOWN"));
m_priv_increase_state(STATE_QUIT);
break;
default:
log_print("monitor_loop: got unknown code %d",
msgcode);
}
}
exit(0);
}
/* Privileged: called by monitor_loop. */
static void
m_priv_ui_init(void)
{
int err = 0;
ui_init();
if (ui_socket < 0)
err = -1;
must_write(&err, sizeof err);
if (ui_socket >= 0 && mm_send_fd(m_state.s, ui_socket)) {
close(ui_socket);
goto errout;
}
/* In case of stdin, we do not close the socket. */
if (ui_socket > 0)
close(ui_socket);
return;
errout:
log_error("m_priv_ui_init: read/write operation failed");
}
/* Privileged: called by monitor_loop. */
static void
m_priv_pfkey_open(void)
{
int fd, err = 0;
fd = pf_key_v2_open();
if (fd < 0)
err = -1;
must_write(&err, sizeof err);
if (fd > 0 && mm_send_fd(m_state.s, fd)) {
close(fd);
goto errout;
}
close(fd);
return;
errout:
log_error("m_priv_pfkey_open: read/write operation failed");
}
/* Privileged: called by monitor_loop. */
static void
m_priv_getfd(void)
{
char path[MAXPATHLEN];
int v, flags, len;
int err = 0;
mode_t mode;
must_read(&len, sizeof len);
if (len <= 0 || len >= sizeof path)
log_fatal("m_priv_getfd: invalid pathname length");
must_read(path, len);
path[len] = '\0';
if (strlen(path) != len)
log_fatal("m_priv_getfd: invalid pathname");
must_read(&flags, sizeof flags);
must_read(&mode, sizeof mode);
if (m_priv_local_sanitize_path(path, sizeof path, flags) != 0) {
err = EACCES;
v = -1;
} else {
v = open(path, flags, mode);
if (v < 0)
err = errno;
}
must_write(&err, sizeof err);
if (v > 0 && mm_send_fd(m_state.s, v)) {
close(v);
goto errout;
}
close(v);
return;
errout:
log_error("m_priv_getfd: read/write operation failed");
}
/* Privileged: called by monitor_loop. */
static void
m_priv_setsockopt(void)
{
int sock, level, optname, v;
int err = 0;
char *optval = 0;
socklen_t optlen;
sock = mm_receive_fd(m_state.s);
if (sock < 0)
goto errout;
must_read(&level, sizeof level);
must_read(&optname, sizeof optname);
must_read(&optlen, sizeof optlen);
optval = (char *)malloc(optlen);
if (!optval)
goto errout;
must_read(optval, (size_t)optlen);
if (m_priv_check_sockopt(level, optname) != 0) {
err = EACCES;
v = -1;
} else {
v = setsockopt(sock, level, optname, optval, optlen);
if (v < 0)
err = errno;
}
close(sock);
sock = -1;
must_write(&err, sizeof err);
must_write(&v, sizeof v);
free(optval);
return;
errout:
log_print("m_priv_setsockopt: read/write error");
if (optval)
free(optval);
if (sock >= 0)
close(sock);
}
/* Privileged: called by monitor_loop. */
static void
m_priv_bind(void)
{
int sock, v, err = 0;
struct sockaddr *name = 0;
socklen_t namelen;
sock = mm_receive_fd(m_state.s);
if (sock < 0)
goto errout;
must_read(&v, sizeof v);
namelen = (socklen_t)v;
name = (struct sockaddr *)malloc(namelen);
if (!name)
goto errout;
must_read((char *)name, (size_t)namelen);
if (m_priv_check_bind(name, namelen) != 0) {
err = EACCES;
v = -1;
} else {
v = bind(sock, name, namelen);
if (v < 0) {
log_error("m_priv_bind: bind(%d,%p,%d) returned %d",
sock, name, namelen, v);
err = errno;
}
}
close(sock);
sock = -1;
must_write(&err, sizeof err);
must_write(&v, sizeof v);
free(name);
return;
errout:
log_print("m_priv_bind: read/write error");
if (name)
free(name);
if (sock >= 0)
close(sock);
}
/*
* Help functions, used by both privileged and unprivileged code
*/
/*
* Read data with the assertion that it all must come through, or else abort
* the process. Based on atomicio() from openssh.
*/
static void
must_read(void *buf, size_t n)
{
char *s = buf;
size_t pos = 0;
ssize_t res;
while (n > pos) {
res = read(m_state.s, s + pos, n - pos);
switch (res) {
case -1:
if (errno == EINTR || errno == EAGAIN)
continue;
case 0:
_exit(0);
default:
pos += res;
}
}
}
/*
* Write data with the assertion that it all has to be written, or else abort
* the process. Based on atomicio() from openssh.
*/
static void
must_write(const void *buf, size_t n)
{
const char *s = buf;
ssize_t res, pos = 0;
while (n > pos) {
res = write(m_state.s, s + pos, n - pos);
switch (res) {
case -1:
if (errno == EINTR || errno == EAGAIN)
continue;
case 0:
_exit(0);
default:
pos += res;
}
}
}
/* Check that path/mode is permitted. */
static int
m_priv_local_sanitize_path(char *path, size_t pmax, int flags)
{
char *p;
/*
* We only permit paths starting with
* /etc/isakmpd/ (read only)
* /var/run/ (rw)
*/
if (strlen(path) < strlen("/var/run/"))
goto bad_path;
/* Any path containing '..' is invalid. */
for (p = path; *p && (p - path) < (int)pmax; p++)
if (*p == '.' && *(p + 1) == '.')
goto bad_path;
/* For any write-mode, only a few paths are permitted. */
if ((flags & O_ACCMODE) != O_RDONLY) {
if (strncmp("/var/run/", path, strlen("/var/run/")) == 0)
return 0;
goto bad_path;
}
/* Any other path is read-only. */
if (strncmp(ISAKMPD_ROOT, path, strlen(ISAKMPD_ROOT)) == 0 ||
strncmp("/var/run/", path, strlen("/var/run/")) == 0)
return 0;
bad_path:
log_print("m_priv_local_sanitize_path: illegal path \"%.1023s\", "
"replaced with \"/dev/null\"", path);
strlcpy(path, "/dev/null", pmax);
return 1;
}
/* Check setsockopt */
static int
m_priv_check_sockopt(int level, int name)
{
switch (level) {
/* These are allowed */
case SOL_SOCKET:
case IPPROTO_IP:
case IPPROTO_IPV6:
break;
default:
log_print("m_priv_check_sockopt: Illegal level %d", level);
return 1;
}
switch (name) {
/* These are allowed */
case SO_REUSEPORT:
case SO_REUSEADDR:
case IP_AUTH_LEVEL:
case IP_ESP_TRANS_LEVEL:
case IP_ESP_NETWORK_LEVEL:
case IP_IPCOMP_LEVEL:
case IPV6_AUTH_LEVEL:
case IPV6_ESP_TRANS_LEVEL:
case IPV6_ESP_NETWORK_LEVEL:
case IPV6_IPCOMP_LEVEL:
break;
default:
log_print("m_priv_check_sockopt: Illegal option name %d",
name);
return 1;
}
return 0;
}
/* Check bind */
static int
m_priv_check_bind(const struct sockaddr *sa, socklen_t salen)
{
in_port_t port;
if (sa == NULL) {
log_print("NULL address");
return 1;
}
if (SA_LEN(sa) != salen) {
log_print("Length mismatch: %lu %lu", (unsigned long)sa->sa_len,
(unsigned long)salen);
return 1;
}
switch (sa->sa_family) {
case AF_INET:
if (salen != sizeof(struct sockaddr_in)) {
log_print("Invalid inet address length");
return 1;
}
port = ((const struct sockaddr_in *)sa)->sin_port;
break;
case AF_INET6:
if (salen != sizeof(struct sockaddr_in6)) {
log_print("Invalid inet6 address length");
return 1;
}
port = ((const struct sockaddr_in6 *)sa)->sin6_port;
break;
default:
log_print("Unknown address family");
return 1;
}
port = ntohs(port);
if (port != ISAKMP_PORT_DEFAULT && port < 1024) {
log_print("Disallowed port %u", port);
return 1;
}
return 0;
}
/* Increase state into less permissive mode */
static void
m_priv_increase_state(int state)
{
if (state <= cur_state)
log_print("m_priv_increase_state: attempt to decrease state "
"or match current state");
if (state < STATE_INIT || state > STATE_QUIT)
log_print("m_priv_increase_state: attempt to switch to "
"invalid state");
cur_state = state;
}
static void
m_priv_test_state(int state)
{
if (cur_state != state)
log_print("m_priv_test_state: Illegal state: %d != %d",
(int)cur_state, state);
}
|