18
18
* along with this program. If not, see
19
19
* <http://www.gnu.org/licenses/>.
21
* Contact the authors at <https://www.fukt.bsnet.se/~belorn/> and
22
* <https://www.fukt.bsnet.se/~teddy/>.
21
* Contact the authors at <mandos@fukt.bsnet.se>.
25
#define _FORTIFY_SOURCE 2
24
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY() */
27
#include <stdio.h> /* popen, fileno */
28
#include <iso646.h> /* and, or, not */
29
#include <sys/types.h> /* DIR, opendir, stat, struct stat, waitpid,
30
WIFEXITED, WEXITSTATUS, wait */
31
#include <sys/wait.h> /* wait */
32
#include <dirent.h> /* DIR, opendir */
33
#include <sys/stat.h> /* stat, struct stat */
34
#include <unistd.h> /* stat, struct stat, chdir */
35
#include <stdlib.h> /* EXIT_FAILURE */
36
#include <sys/select.h> /* fd_set, select, FD_ZERO, FD_SET,
38
#include <string.h> /* strlen, strcpy, strcat */
39
#include <stdbool.h> /* true */
40
#include <sys/wait.h> /* waitpid, WIFEXITED, WEXITSTATUS */
41
#include <errno.h> /* errno */
42
#include <argp.h> /* argp */
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(),
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(),
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(),
48
#include <errno.h> /* errno */
49
#include <argp.h> /* struct argp_option,
50
struct argp_state, struct argp,
100
112
p->argv[p->argc] = NULL;
116
* Based on the example in the GNU LibC manual chapter 13.13 "File
118
* *Note File Descriptor Flags:(libc)Descriptor Flags.
120
int set_cloexec_flag(int fd)
122
int ret = fcntl(fd, F_GETFD, 0);
123
/* If reading the flags failed, return error indication now. */
127
/* Store modified flag word in the descriptor. */
128
return fcntl(fd, F_SETFD, ret | FD_CLOEXEC);
103
131
#define BUFFER_SIZE 256
105
const char *argp_program_version =
106
"plugbasedclient 0.9";
107
const char *argp_program_bug_address =
108
"<mandos@fukt.bsnet.se>";
110
"Mandos plugin runner -- Run Mandos plugins";
111
/* A description of the arguments we accept. */
112
static char args_doc[] = "";
133
const char *argp_program_version = "plugbasedclient 0.9";
134
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
136
process *process_list = NULL;
138
/* Mark a process as completed when it exits, and save its exit
140
void handle_sigchld(__attribute__((unused)) int sig){
141
process *proc = process_list;
143
pid_t pid = wait(&status);
144
while(proc != NULL and proc->pid != pid){
148
/* Process not found in process list */
151
proc->status = status;
152
proc->completed = true;
114
155
int main(int argc, char *argv[]){
115
const char *plugindir = "plugins.d";
156
const char *plugindir = "/conf/conf.d/mandos/plugins.d";
116
157
size_t d_name_len;
118
159
struct dirent *dirst;
121
162
int ret, maxfd = 0;
122
process *process_list = NULL;
123
163
uid_t uid = 65534;
124
164
gid_t gid = 65534;
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;
173
/* Establish a signal handler */
174
sigemptyset(&sigchld_action.sa_mask);
175
ret = sigaddset(&sigchld_action.sa_mask, SIGCHLD);
180
ret = sigaction(SIGCHLD, &sigchld_action, &old_sigchld_action);
125
186
/* The options we understand. */
126
187
struct argp_option options[] = {
127
188
{ .name = "global-options", .key = 'g',
128
.arg = "option[,option[,...]]", .flags = 0,
129
.doc = "Options effecting all plugins" },
189
.arg = "OPTION[,OPTION[,...]]",
190
.doc = "Options passed to all plugins" },
130
191
{ .name = "options-for", .key = 'o',
131
.arg = "plugin:option[,option[,...]]", .flags = 0,
132
.doc = "Options effecting only specified plugins" },
133
{ .name = "disable-plugin", .key = 'd',
134
.arg = "Plugin[,Plugin[,...]]", .flags = 0,
135
.doc = "Option to disable specififed plugins" },
192
.arg = "PLUGIN:OPTION[,OPTION[,...]]",
193
.doc = "Options passed only to specified plugin" },
194
{ .name = "disable", .key = 'd',
196
.doc = "Disable a specific plugin", .group = 1 },
136
197
{ .name = "plugin-dir", .key = 128,
137
.arg = "Directory", .flags = 0,
138
.doc = "Option to change directory to search for plugins" },
199
.doc = "Specify a different plugin directory", .group = 2 },
139
200
{ .name = "userid", .key = 129,
140
.arg = "Id", .flags = 0,
141
.doc = "Option to change which user id the plugins will run as" },
201
.arg = "ID", .flags = 0,
202
.doc = "User ID the plugins will run as", .group = 2 },
142
203
{ .name = "groupid", .key = 130,
143
.arg = "Id", .flags = 0,
144
.doc = "Option to change which group id the plugins will run as" },
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 },
148
211
error_t parse_opt (int key, char *arg, struct argp_state *state) {
149
/* Get the INPUT argument from `argp_parse', which we
150
know is a pointer to our arguments structure. */
212
/* Get the INPUT argument from `argp_parse', which we know is a
213
pointer to our plugin list pointer. */
151
214
plugin **plugins = state->input;
154
217
if (arg != NULL){
155
218
char *p = strtok(arg, ",");
157
addarguments(getplugin(NULL, plugins), p);
220
addargument(getplugin(NULL, plugins), p);
158
221
p = strtok(NULL, ",");
163
226
if (arg != NULL){
164
227
char *name = strtok(arg, ":");
165
228
char *p = strtok(NULL, ":");
168
addarguments(getplugin(name, plugins), p);
169
p = strtok(NULL, ",");
232
addargument(getplugin(name, plugins), p);
233
p = strtok(NULL, ",");
174
239
if (arg != NULL){
175
char *p = strtok(arg, ",");
177
getplugin(p, plugins)->disable = true;
178
p = strtok(NULL, ",");
240
getplugin(arg, plugins)->disabled = true;
202
269
plugin *plugin_list = NULL;
204
271
struct argp argp = { .options = options, .parser = parse_opt,
205
.args_doc = args_doc, .doc = doc };
207
argp_parse (&argp, argc, argv, 0, 0, &plugin_list);
209
/* for(plugin *p = plugin_list; p != NULL; p=p->next){ */
210
/* fprintf(stderr, "Plugin: %s has %d arguments\n", p->name ? p->name : "Global", p->argc); */
211
/* for(char **a = p->argv + 1; *a != NULL; a++){ */
212
/* fprintf(stderr, "\tArg: %s\n", *a); */
272
.args_doc = "[+PLUS_SEPARATED_OPTIONS]",
273
.doc = "Mandos plugin runner -- Run plugins" };
275
argp_parse (&argp, argc, argv, 0, 0, &plugin_list);
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[] = "+";
285
plus_argv = malloc(sizeof(char*) * 2);
286
if(plus_argv == NULL){
288
exitstatus = EXIT_FAILURE;
291
plus_argv[0] = argv[0];
293
arg = strtok(plus_options, delims); /* Get first argument */
296
plus_argv = realloc(plus_argv, sizeof(char *)
297
* ((unsigned int) new_argc + 1));
298
if(plus_argv == NULL){
300
exitstatus = EXIT_FAILURE;
303
plus_argv[new_argc-1] = arg;
304
plus_argv[new_argc] = NULL;
305
arg = strtok(NULL, delims); /* Get next argument */
307
argp_parse (&argp, new_argc, plus_argv, 0, 0, &plugin_list);
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);
218
320
ret = setuid(uid);
220
322
perror("setuid");
225
327
perror("setuid");
228
330
dir = opendir(plugindir);
231
fprintf(stderr, "Can not open directory\n");
332
perror("Could not open plugin dir");
333
exitstatus = EXIT_FAILURE;
337
/* Set the FD_CLOEXEC flag on the directory, if possible */
339
int dir_fd = dirfd(dir);
341
ret = set_cloexec_flag(dir_fd);
343
perror("set_cloexec_flag");
344
exitstatus = EXIT_FAILURE;
238
353
dirst = readdir(dir);
245
360
d_name_len = strlen(dirst->d_name);
247
// Ignore dotfiles and backup files
248
if (dirst->d_name[0] == '.'
249
or dirst->d_name[d_name_len - 1] == '~'){
362
// Ignore dotfiles, backup files and other junk
364
bool bad_name = false;
366
const char const *bad_prefixes[] = { ".", "#", NULL };
368
const char const *bad_suffixes[] = { "~", "#", ".dpkg-new",
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){
376
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
377
" with bad prefix %s\n", dirst->d_name, *pre);
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)
394
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
395
" with bad suffix %s\n", dirst->d_name, *suf);
253
407
char *filename = malloc(d_name_len + strlen(plugindir) + 2);
254
strcpy(filename, plugindir);
255
strcat(filename, "/");
256
strcat(filename, dirst->d_name);
408
if (filename == NULL){
410
exitstatus = EXIT_FAILURE;
413
strcpy(filename, plugindir); /* Spurious warning */
414
strcat(filename, "/"); /* Spurious warning */
415
strcat(filename, dirst->d_name); /* Spurious warning */
258
417
stat(filename, &st);
260
if (S_ISREG(st.st_mode)
261
and (access(filename, X_OK) == 0)
262
and not (getplugin(dirst->d_name, &plugin_list)->disable)){
263
// Starting a new process to be watched
264
process *new_process = malloc(sizeof(process));
271
new_process->pid = fork();
272
if(new_process->pid == 0){
273
/* this is the child process */
419
if (not S_ISREG(st.st_mode) or (access(filename, X_OK) != 0)){
421
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
422
" with bad type or mode\n", filename);
427
if(getplugin(dirst->d_name, &plugin_list)->disabled){
429
fprintf(stderr, "Ignoring disabled plugin \"%s\"\n",
435
plugin *p = getplugin(dirst->d_name, &plugin_list);
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++){
447
exitstatus = EXIT_FAILURE;
450
ret = set_cloexec_flag(pipefd[0]);
452
perror("set_cloexec_flag");
453
exitstatus = EXIT_FAILURE;
456
ret = set_cloexec_flag(pipefd[1]);
458
perror("set_cloexec_flag");
459
exitstatus = EXIT_FAILURE;
462
/* Block SIGCHLD until process is safely in process list */
463
ret = sigprocmask (SIG_BLOCK, &sigchld_action.sa_mask, NULL);
465
perror("sigprocmask");
466
exitstatus = EXIT_FAILURE;
469
// Starting a new process to be watched
472
/* this is the child process */
473
ret = sigaction(SIGCHLD, &old_sigchld_action, NULL);
478
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
480
perror("sigprocmask");
483
dup2(pipefd[1], STDOUT_FILENO); /* replace our stdout */
486
/* If dir has no file descriptor, we could not set FD_CLOEXEC
487
above and must now close it manually here. */
275
close(pipefd[0]); /* close unused read end of pipe */
276
dup2(pipefd[1], STDOUT_FILENO); /* replace our stdout */
278
plugin *p = getplugin(dirst->d_name, &plugin_list);
279
plugin *g = getplugin(NULL, &plugin_list);
280
for(char **a = g->argv + 1; *a != NULL; a++){
283
if(execv(filename, p->argv) < 0){
290
close(pipefd[1]); /* close unused write end of pipe */
291
new_process->fd = pipefd[0];
292
new_process->buffer = malloc(BUFFER_SIZE);
293
if (new_process->buffer == NULL){
297
new_process->buffer_size = BUFFER_SIZE;
298
new_process->buffer_length = 0;
299
FD_SET(new_process->fd, &rfds_orig);
301
if (maxfd < new_process->fd){
302
maxfd = new_process->fd;
306
new_process->next = process_list;
307
process_list = new_process;
490
if(execv(filename, p->argv) < 0){
498
close(pipefd[1]); /* close unused write end of pipe */
499
process *new_process = malloc(sizeof(process));
500
if (new_process == NULL){
502
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
504
perror("sigprocmask");
506
exitstatus = EXIT_FAILURE;
510
*new_process = (struct process){ .pid = pid,
512
.next = process_list };
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);
519
perror("sigprocmask");
520
exitstatus = EXIT_FAILURE;
524
FD_SET(new_process->fd, &rfds_all);
526
if (maxfd < new_process->fd){
527
maxfd = new_process->fd;
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);
313
if (process_list != NULL){
315
fd_set rfds = rfds_orig;
316
int select_ret = select(maxfd+1, &rfds, NULL, NULL, NULL);
317
if (select_ret == -1){
321
for(process *process_itr = process_list; process_itr != NULL;
322
process_itr = process_itr->next){
323
if(FD_ISSET(process_itr->fd, &rfds)){
324
if(process_itr->buffer_length + BUFFER_SIZE
325
> process_itr->buffer_size){
326
process_itr->buffer = realloc(process_itr->buffer,
327
process_itr->buffer_size
328
+ (size_t) BUFFER_SIZE);
329
if (process_itr->buffer == NULL){
333
process_itr->buffer_size += BUFFER_SIZE;
335
ret = read(process_itr->fd, process_itr->buffer
336
+ process_itr->buffer_length, BUFFER_SIZE);
338
/* Read error from this process; ignore it */
341
process_itr->buffer_length += (size_t) ret;
344
/* wait for process exit */
346
waitpid(process_itr->pid, &status, 0);
347
if(WIFEXITED(status) and WEXITSTATUS(status) == 0){
348
for(size_t written = 0;
349
written < process_itr->buffer_length;){
350
ret = write(STDOUT_FILENO,
351
process_itr->buffer + written,
352
process_itr->buffer_length - written);
357
written += (size_t)ret;
361
FD_CLR(process_itr->fd, &rfds_orig);
542
if (process_list == NULL){
543
fprintf(stderr, "No plugin processes started, exiting\n");
544
exitstatus = EXIT_FAILURE;
548
fd_set rfds = rfds_all;
549
int select_ret = select(maxfd+1, &rfds, NULL, NULL, NULL);
550
if (select_ret == -1){
552
exitstatus = EXIT_FAILURE;
555
/* OK, now either a process completed, or something can be read
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 */
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);
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);
580
perror("sigprocmask");
581
exitstatus = EXIT_FAILURE;
584
/* Delete this process entry from the list */
585
if(process_list == proc){
586
/* First one - simple */
587
process_list = proc->next;
589
/* Second one or later */
590
for(process *p = process_list; p != NULL; p = p->next){
592
p->next = proc->next;
597
/* We are done modifying process list, so unblock signal */
598
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask,
601
perror("sigprocmask");
605
/* We deleted this process from the list, so we can't go
606
proc->next. Therefore, start over from the beginning of
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,
619
exitstatus = EXIT_FAILURE;
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 */
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){
636
exitstatus = EXIT_FAILURE;
639
proc->buffer_size += BUFFER_SIZE;
641
/* Read from the process */
642
ret = read(proc->fd, proc->buffer + proc->buffer_length,
645
/* Read error from this process; ignore the error */
652
proc->buffer_length += (size_t) ret;
656
if(process_list == NULL){
657
fprintf(stderr, "All plugin processes failed, exiting\n");
658
exitstatus = EXIT_FAILURE;
371
for(process *process_itr = process_list; process_itr != NULL;
372
process_itr = process_itr->next){
373
close(process_itr->fd);
374
kill(process_itr->pid, SIGTERM);
375
free(process_itr->buffer);
662
/* Restore old signal handler */
663
sigaction(SIGCHLD, &old_sigchld_action, NULL);
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);
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);
687
/* Wait for any remaining child processes to terminate */