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- Committer: Björn Påhlsson
- Date: 2007-10-20 21:38:25 UTC
- Revision ID: belorn@tower-20071020213825-abf6f0d1c33ee961
First working version with: IPv6, GnuTLS, X.509 certificates, DN
retrieval.
retrieval.
- files added:
- bad-ca.pem
- files removed:
- TODO
- plugins.d
- files modified:
- Makefile
added
removed
plugbasedclient.c
1
/* -*- coding: utf-8 -*- */
2
/*
3
* Mandos plugin runner - Run Mandos plugins
4
*
5
* Copyright © 2007-2008 Teddy Hogeborn & Björn Påhlsson
6
*
7
* This program is free software: you can redistribute it and/or
8
* modify it under the terms of the GNU General Public License as
9
* published by the Free Software Foundation, either version 3 of the
10
* License, or (at your option) any later version.
11
*
12
* This program is distributed in the hope that it will be useful, but
13
* WITHOUT ANY WARRANTY; without even the implied warranty of
14
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15
* General Public License for more details.
16
*
17
* You should have received a copy of the GNU General Public License
18
* along with this program. If not, see
19
* <http://www.gnu.org/licenses/>.
20
*
21
* Contact the authors at <mandos@fukt.bsnet.se>.
22
*/
23
24
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY() */
25
26
#include <stdio.h> /* popen(), fileno(), fprintf(),
27
stderr, STDOUT_FILENO */
28
#include <iso646.h> /* and, or, not */
29
#include <sys/types.h> /* DIR, opendir(), stat(),
30
struct stat, waitpid(),
31
WIFEXITED(), WEXITSTATUS(),
32
wait() */
33
#include <sys/wait.h> /* wait() */
34
#include <dirent.h> /* DIR, struct dirent, opendir(),
35
readdir(), closedir() */
36
#include <sys/stat.h> /* struct stat, stat(), S_ISREG() */
37
#include <unistd.h> /* struct stat, stat(), S_ISREG(),
38
fcntl() */
39
#include <fcntl.h> /* fcntl() */
40
#include <stddef.h> /* NULL */
41
#include <stdlib.h> /* EXIT_FAILURE */
42
#include <sys/select.h> /* fd_set, select(), FD_ZERO(),
43
FD_SET(), FD_ISSET() */
44
#include <string.h> /* strlen(), strcpy(), strcat() */
45
#include <stdbool.h> /* true */
46
#include <sys/wait.h> /* waitpid(), WIFEXITED(),
47
WEXITSTATUS() */
48
#include <errno.h> /* errno */
49
#include <argp.h> /* struct argp_option,
50
struct argp_state, struct argp,
51
argp_parse() */
52
53
#define BUFFER_SIZE 256
54
55
struct process;
56
57
typedef struct process{
58
pid_t pid;
59
int fd;
60
char *buffer;
61
size_t buffer_size;
62
size_t buffer_length;
63
bool eof;
64
bool completed;
65
int status;
66
struct process *next;
67
} process;
68
69
typedef struct plugin{
70
char *name; /* can be NULL or any plugin name */
71
char **argv;
72
int argc;
73
bool disabled;
74
struct plugin *next;
75
} plugin;
76
77
static plugin *getplugin(char *name, plugin **plugin_list){
78
for (plugin *p = *plugin_list; p != NULL; p = p->next){
79
if ((p->name == name)
80
or (p->name and name and (strcmp(p->name, name) == 0))){
81
return p;
82
}
83
}
84
/* Create a new plugin */
85
plugin *new_plugin = malloc(sizeof(plugin));
86
if (new_plugin == NULL){
87
perror("malloc");
88
exit(EXIT_FAILURE);
89
}
90
new_plugin->name = name;
91
new_plugin->argv = malloc(sizeof(char *) * 2);
92
if (new_plugin->argv == NULL){
93
perror("malloc");
94
exit(EXIT_FAILURE);
95
}
96
new_plugin->argv[0] = name;
97
new_plugin->argv[1] = NULL;
98
new_plugin->argc = 1;
99
new_plugin->disabled = false;
100
new_plugin->next = *plugin_list;
101
/* Append the new plugin to the list */
102
*plugin_list = new_plugin;
103
return new_plugin;
104
}
105
106
static void addargument(plugin *p, char *arg){
107
p->argv[p->argc] = arg;
108
p->argv = realloc(p->argv, sizeof(char *) * (size_t)(p->argc + 2));
109
if (p->argv == NULL){
110
perror("malloc");
111
exit(EXIT_FAILURE);
112
}
113
p->argc++;
114
p->argv[p->argc] = NULL;
115
}
116
117
/*
118
* Based on the example in the GNU LibC manual chapter 13.13 "File
119
* Descriptor Flags".
120
* *Note File Descriptor Flags:(libc)Descriptor Flags.
121
*/
122
static int set_cloexec_flag(int fd)
123
{
124
int ret = fcntl(fd, F_GETFD, 0);
125
/* If reading the flags failed, return error indication now. */
126
if(ret < 0){
127
return ret;
128
}
129
/* Store modified flag word in the descriptor. */
130
return fcntl(fd, F_SETFD, ret | FD_CLOEXEC);
131
}
132
133
const char *argp_program_version = "plugbasedclient 0.9";
134
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
135
136
process *process_list = NULL;
137
138
/* Mark a process as completed when it exits, and save its exit
139
status. */
140
void handle_sigchld(__attribute__((unused)) int sig){
141
process *proc = process_list;
142
int status;
143
pid_t pid = wait(&status);
144
while(proc != NULL and proc->pid != pid){
145
proc = proc->next;
146
}
147
if(proc == NULL){
148
/* Process not found in process list */
149
return;
150
}
151
proc->status = status;
152
proc->completed = true;
153
}
154
155
int main(int argc, char *argv[]){
156
const char *plugindir = "/conf/conf.d/mandos/plugins.d";
157
size_t d_name_len;
158
DIR *dir = NULL;
159
struct dirent *dirst;
160
struct stat st;
161
fd_set rfds_all;
162
int ret, maxfd = 0;
163
uid_t uid = 65534;
164
gid_t gid = 65534;
165
bool debug = false;
166
int exitstatus = EXIT_SUCCESS;
167
struct sigaction old_sigchld_action;
168
struct sigaction sigchld_action = { .sa_handler = handle_sigchld,
169
.sa_flags = SA_NOCLDSTOP };
170
char *plus_options = NULL;
171
char **plus_argv = NULL;
172
173
/* Establish a signal handler */
174
sigemptyset(&sigchld_action.sa_mask);
175
ret = sigaddset(&sigchld_action.sa_mask, SIGCHLD);
176
if(ret < 0){
177
perror("sigaddset");
178
exit(EXIT_FAILURE);
179
}
180
ret = sigaction(SIGCHLD, &sigchld_action, &old_sigchld_action);
181
if(ret < 0){
182
perror("sigaction");
183
exit(EXIT_FAILURE);
184
}
185
186
/* The options we understand. */
187
struct argp_option options[] = {
188
{ .name = "global-options", .key = 'g',
189
.arg = "OPTION[,OPTION[,...]]",
190
.doc = "Options passed to all plugins" },
191
{ .name = "options-for", .key = 'o',
192
.arg = "PLUGIN:OPTION[,OPTION[,...]]",
193
.doc = "Options passed only to specified plugin" },
194
{ .name = "disable", .key = 'd',
195
.arg = "PLUGIN",
196
.doc = "Disable a specific plugin", .group = 1 },
197
{ .name = "plugin-dir", .key = 128,
198
.arg = "DIRECTORY",
199
.doc = "Specify a different plugin directory", .group = 2 },
200
{ .name = "userid", .key = 129,
201
.arg = "ID", .flags = 0,
202
.doc = "User ID the plugins will run as", .group = 2 },
203
{ .name = "groupid", .key = 130,
204
.arg = "ID", .flags = 0,
205
.doc = "Group ID the plugins will run as", .group = 2 },
206
{ .name = "debug", .key = 131,
207
.doc = "Debug mode", .group = 3 },
208
{ .name = NULL }
209
};
210
211
error_t parse_opt (int key, char *arg, struct argp_state *state) {
212
/* Get the INPUT argument from `argp_parse', which we know is a
213
pointer to our plugin list pointer. */
214
plugin **plugins = state->input;
215
switch (key) {
216
case 'g':
217
if (arg != NULL){
218
char *p = strtok(arg, ",");
219
do{
220
addargument(getplugin(NULL, plugins), p);
221
p = strtok(NULL, ",");
222
} while (p != NULL);
223
}
224
break;
225
case 'o':
226
if (arg != NULL){
227
char *name = strtok(arg, ":");
228
char *p = strtok(NULL, ":");
229
if(p != NULL){
230
p = strtok(p, ",");
231
do{
232
addargument(getplugin(name, plugins), p);
233
p = strtok(NULL, ",");
234
} while (p != NULL);
235
}
236
}
237
break;
238
case 'd':
239
if (arg != NULL){
240
getplugin(arg, plugins)->disabled = true;
241
}
242
break;
243
case 128:
244
plugindir = arg;
245
break;
246
case 129:
247
uid = (uid_t)strtol(arg, NULL, 10);
248
break;
249
case 130:
250
gid = (gid_t)strtol(arg, NULL, 10);
251
break;
252
case 131:
253
debug = true;
254
break;
255
case ARGP_KEY_ARG:
256
if(plus_options != NULL or arg == NULL or arg[0] != '+'){
257
argp_usage (state);
258
}
259
plus_options = arg;
260
break;
261
case ARGP_KEY_END:
262
break;
263
default:
264
return ARGP_ERR_UNKNOWN;
265
}
266
return 0;
267
}
268
269
plugin *plugin_list = NULL;
270
271
struct argp argp = { .options = options, .parser = parse_opt,
272
.args_doc = "[+PLUS_SEPARATED_OPTIONS]",
273
.doc = "Mandos plugin runner -- Run plugins" };
274
275
argp_parse (&argp, argc, argv, 0, 0, &plugin_list);
276
277
if(plus_options){
278
/* This is a mangled argument in the form of
279
"+--option+--other-option=parameter+--yet-another-option", etc */
280
/* Make new argc and argv vars, and call argp_parse() again. */
281
plus_options++; /* skip the first '+' character */
282
const char delims[] = "+";
283
char *arg;
284
int new_argc = 1;
285
plus_argv = malloc(sizeof(char*) * 2);
286
if(plus_argv == NULL){
287
perror("malloc");
288
exitstatus = EXIT_FAILURE;
289
goto end;
290
}
291
plus_argv[0] = argv[0];
292
plus_argv[1] = NULL;
293
arg = strtok(plus_options, delims); /* Get first argument */
294
while(arg != NULL){
295
new_argc++;
296
plus_argv = realloc(plus_argv, sizeof(char *)
297
* ((unsigned int) new_argc + 1));
298
if(plus_argv == NULL){
299
perror("malloc");
300
exitstatus = EXIT_FAILURE;
301
goto end;
302
}
303
plus_argv[new_argc-1] = arg;
304
plus_argv[new_argc] = NULL;
305
arg = strtok(NULL, delims); /* Get next argument */
306
}
307
argp_parse (&argp, new_argc, plus_argv, 0, 0, &plugin_list);
308
}
309
310
if(debug){
311
for(plugin *p = plugin_list; p != NULL; p=p->next){
312
fprintf(stderr, "Plugin: %s has %d arguments\n",
313
p->name ? p->name : "Global", p->argc - 1);
314
for(char **a = p->argv; *a != NULL; a++){
315
fprintf(stderr, "\tArg: %s\n", *a);
316
}
317
}
318
}
319
320
ret = setuid(uid);
321
if (ret == -1){
322
perror("setuid");
323
}
324
325
setgid(gid);
326
if (ret == -1){
327
perror("setgid");
328
}
329
330
dir = opendir(plugindir);
331
if(dir == NULL){
332
perror("Could not open plugin dir");
333
exitstatus = EXIT_FAILURE;
334
goto end;
335
}
336
337
/* Set the FD_CLOEXEC flag on the directory, if possible */
338
{
339
int dir_fd = dirfd(dir);
340
if(dir_fd >= 0){
341
ret = set_cloexec_flag(dir_fd);
342
if(ret < 0){
343
perror("set_cloexec_flag");
344
exitstatus = EXIT_FAILURE;
345
goto end;
346
}
347
}
348
}
349
350
FD_ZERO(&rfds_all);
351
352
while(true){
353
dirst = readdir(dir);
354
355
// All directory entries have been processed
356
if(dirst == NULL){
357
break;
358
}
359
360
d_name_len = strlen(dirst->d_name);
361
362
// Ignore dotfiles, backup files and other junk
363
{
364
bool bad_name = false;
365
366
const char const *bad_prefixes[] = { ".", "#", NULL };
367
368
const char const *bad_suffixes[] = { "~", "#", ".dpkg-new",
369
".dpkg-old",
370
".dpkg-divert", NULL };
371
for(const char **pre = bad_prefixes; *pre != NULL; pre++){
372
size_t pre_len = strlen(*pre);
373
if((d_name_len >= pre_len)
374
and strncmp((dirst->d_name), *pre, pre_len) == 0){
375
if(debug){
376
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
377
" with bad prefix %s\n", dirst->d_name, *pre);
378
}
379
bad_name = true;
380
break;
381
}
382
}
383
384
if(bad_name){
385
continue;
386
}
387
388
for(const char **suf = bad_suffixes; *suf != NULL; suf++){
389
size_t suf_len = strlen(*suf);
390
if((d_name_len >= suf_len)
391
and (strcmp((dirst->d_name)+d_name_len-suf_len, *suf)
392
== 0)){
393
if(debug){
394
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
395
" with bad suffix %s\n", dirst->d_name, *suf);
396
}
397
bad_name = true;
398
break;
399
}
400
}
401
402
if(bad_name){
403
continue;
404
}
405
}
406
407
char *filename = malloc(d_name_len + strlen(plugindir) + 2);
408
if (filename == NULL){
409
perror("malloc");
410
exitstatus = EXIT_FAILURE;
411
goto end;
412
}
413
strcpy(filename, plugindir); /* Spurious warning */
414
strcat(filename, "/"); /* Spurious warning */
415
strcat(filename, dirst->d_name); /* Spurious warning */
416
417
stat(filename, &st);
418
419
if (not S_ISREG(st.st_mode) or (access(filename, X_OK) != 0)){
420
if(debug){
421
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
422
" with bad type or mode\n", filename);
423
}
424
free(filename);
425
continue;
426
}
427
if(getplugin(dirst->d_name, &plugin_list)->disabled){
428
if(debug){
429
fprintf(stderr, "Ignoring disabled plugin \"%s\"\n",
430
dirst->d_name);
431
}
432
free(filename);
433
continue;
434
}
435
plugin *p = getplugin(dirst->d_name, &plugin_list);
436
{
437
/* Add global arguments to argument list for this plugin */
438
plugin *g = getplugin(NULL, &plugin_list);
439
for(char **a = g->argv + 1; *a != NULL; a++){
440
addargument(p, *a);
441
}
442
}
443
int pipefd[2];
444
ret = pipe(pipefd);
445
if (ret == -1){
446
perror("pipe");
447
exitstatus = EXIT_FAILURE;
448
goto end;
449
}
450
ret = set_cloexec_flag(pipefd[0]);
451
if(ret < 0){
452
perror("set_cloexec_flag");
453
exitstatus = EXIT_FAILURE;
454
goto end;
455
}
456
ret = set_cloexec_flag(pipefd[1]);
457
if(ret < 0){
458
perror("set_cloexec_flag");
459
exitstatus = EXIT_FAILURE;
460
goto end;
461
}
462
/* Block SIGCHLD until process is safely in process list */
463
ret = sigprocmask (SIG_BLOCK, &sigchld_action.sa_mask, NULL);
464
if(ret < 0){
465
perror("sigprocmask");
466
exitstatus = EXIT_FAILURE;
467
goto end;
468
}
469
// Starting a new process to be watched
470
pid_t pid = fork();
471
if(pid == 0){
472
/* this is the child process */
473
ret = sigaction(SIGCHLD, &old_sigchld_action, NULL);
474
if(ret < 0){
475
perror("sigaction");
476
_exit(EXIT_FAILURE);
477
}
478
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
479
if(ret < 0){
480
perror("sigprocmask");
481
_exit(EXIT_FAILURE);
482
}
483
dup2(pipefd[1], STDOUT_FILENO); /* replace our stdout */
484
485
if(dirfd(dir) < 0){
486
/* If dir has no file descriptor, we could not set FD_CLOEXEC
487
above and must now close it manually here. */
488
closedir(dir);
489
}
490
if(execv(filename, p->argv) < 0){
491
perror("execv");
492
_exit(EXIT_FAILURE);
493
}
494
/* no return */
495
}
496
/* parent process */
497
free(filename);
498
close(pipefd[1]); /* close unused write end of pipe */
499
process *new_process = malloc(sizeof(process));
500
if (new_process == NULL){
501
perror("malloc");
502
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
503
if(ret < 0){
504
perror("sigprocmask");
505
}
506
exitstatus = EXIT_FAILURE;
507
goto end;
508
}
509
510
*new_process = (struct process){ .pid = pid,
511
.fd = pipefd[0],
512
.next = process_list };
513
// List handling
514
process_list = new_process;
515
/* Unblock SIGCHLD so signal handler can be run if this process
516
has already completed */
517
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
518
if(ret < 0){
519
perror("sigprocmask");
520
exitstatus = EXIT_FAILURE;
521
goto end;
522
}
523
524
FD_SET(new_process->fd, &rfds_all);
525
526
if (maxfd < new_process->fd){
527
maxfd = new_process->fd;
528
}
529
530
}
531
532
/* Free the plugin list */
533
for(plugin *next; plugin_list != NULL; plugin_list = next){
534
next = plugin_list->next;
535
free(plugin_list->argv);
536
free(plugin_list);
537
}
538
539
closedir(dir);
540
dir = NULL;
541
542
if (process_list == NULL){
543
fprintf(stderr, "No plugin processes started, exiting\n");
544
exitstatus = EXIT_FAILURE;
545
goto end;
546
}
547
while(process_list){
548
fd_set rfds = rfds_all;
549
int select_ret = select(maxfd+1, &rfds, NULL, NULL, NULL);
550
if (select_ret == -1){
551
perror("select");
552
exitstatus = EXIT_FAILURE;
553
goto end;
554
}
555
/* OK, now either a process completed, or something can be read
556
from one of them */
557
for(process *proc = process_list; proc ; proc = proc->next){
558
/* Is this process completely done? */
559
if(proc->eof and proc->completed){
560
/* Only accept the plugin output if it exited cleanly */
561
if(not WIFEXITED(proc->status)
562
or WEXITSTATUS(proc->status) != 0){
563
/* Bad exit by plugin */
564
if(debug){
565
if(WIFEXITED(proc->status)){
566
fprintf(stderr, "Plugin %d exited with status %d\n",
567
proc->pid, WEXITSTATUS(proc->status));
568
} else if(WIFSIGNALED(proc->status)) {
569
fprintf(stderr, "Plugin %d killed by signal %d\n",
570
proc->pid, WTERMSIG(proc->status));
571
} else if(WCOREDUMP(proc->status)){
572
fprintf(stderr, "Plugin %d dumped core\n", proc->pid);
573
}
574
}
575
/* Remove the plugin */
576
FD_CLR(proc->fd, &rfds_all);
577
/* Block signal while modifying process_list */
578
ret = sigprocmask (SIG_BLOCK, &sigchld_action.sa_mask, NULL);
579
if(ret < 0){
580
perror("sigprocmask");
581
exitstatus = EXIT_FAILURE;
582
goto end;
583
}
584
/* Delete this process entry from the list */
585
if(process_list == proc){
586
/* First one - simple */
587
process_list = proc->next;
588
} else {
589
/* Second one or later */
590
for(process *p = process_list; p != NULL; p = p->next){
591
if(p->next == proc){
592
p->next = proc->next;
593
break;
594
}
595
}
596
}
597
/* We are done modifying process list, so unblock signal */
598
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask,
599
NULL);
600
if(ret < 0){
601
perror("sigprocmask");
602
}
603
free(proc->buffer);
604
free(proc);
605
/* We deleted this process from the list, so we can't go
606
proc->next. Therefore, start over from the beginning of
607
the process list */
608
break;
609
}
610
/* This process exited nicely, so print its buffer */
611
for(size_t written = 0; written < proc->buffer_length;
612
written += (size_t)ret){
613
ret = TEMP_FAILURE_RETRY(write(STDOUT_FILENO,
614
proc->buffer + written,
615
proc->buffer_length
616
- written));
617
if(ret < 0){
618
perror("write");
619
exitstatus = EXIT_FAILURE;
620
goto end;
621
}
622
}
623
goto end;
624
}
625
/* This process has not completed. Does it have any output? */
626
if(proc->eof or not FD_ISSET(proc->fd, &rfds)){
627
/* This process had nothing to say at this time */
628
continue;
629
}
630
/* Before reading, make the process' data buffer large enough */
631
if(proc->buffer_length + BUFFER_SIZE > proc->buffer_size){
632
proc->buffer = realloc(proc->buffer, proc->buffer_size
633
+ (size_t) BUFFER_SIZE);
634
if (proc->buffer == NULL){
635
perror("malloc");
636
exitstatus = EXIT_FAILURE;
637
goto end;
638
}
639
proc->buffer_size += BUFFER_SIZE;
640
}
641
/* Read from the process */
642
ret = read(proc->fd, proc->buffer + proc->buffer_length,
643
BUFFER_SIZE);
644
if(ret < 0){
645
/* Read error from this process; ignore the error */
646
continue;
647
}
648
if(ret == 0){
649
/* got EOF */
650
proc->eof = true;
651
} else {
652
proc->buffer_length += (size_t) ret;
653
}
654
}
655
}
656
if(process_list == NULL){
657
fprintf(stderr, "All plugin processes failed, exiting\n");
658
exitstatus = EXIT_FAILURE;
659
}
660
661
end:
662
/* Restore old signal handler */
663
sigaction(SIGCHLD, &old_sigchld_action, NULL);
664
665
free(plus_argv);
666
667
/* Free the plugin list */
668
for(plugin *next; plugin_list != NULL; plugin_list = next){
669
next = plugin_list->next;
670
free(plugin_list->argv);
671
free(plugin_list);
672
}
673
674
if(dir != NULL){
675
closedir(dir);
676
}
677
678
/* Free the process list and kill the processes */
679
for(process *next; process_list != NULL; process_list = next){
680
next = process_list->next;
681
close(process_list->fd);
682
kill(process_list->pid, SIGTERM);
683
free(process_list->buffer);
684
free(process_list);
685
}
686
687
/* Wait for any remaining child processes to terminate */
688
do{
689
ret = wait(NULL);
690
} while(ret >= 0);
691
if(errno != ECHILD){
692
perror("wait");
693
}
694
695
return exitstatus;
696
}
Loggerhead is a web-based interface for Breezy
Version: 2.0.2.dev0