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
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 */
24
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY() */
26
#include <stddef.h> /* size_t, NULL */
27
#include <stdlib.h> /* malloc(), exit(), EXIT_FAILURE,
28
EXIT_SUCCESS, realloc() */
29
#include <stdbool.h> /* bool, true, false */
30
#include <stdio.h> /* perror, popen(), fileno(),
31
fprintf(), stderr, STDOUT_FILENO */
32
#include <sys/types.h> /* DIR, opendir(), stat(), struct
33
stat, waitpid(), WIFEXITED(),
34
WEXITSTATUS(), wait(), pid_t,
35
uid_t, gid_t, getuid(), getgid(),
37
#include <sys/select.h> /* fd_set, select(), FD_ZERO(),
38
FD_SET(), FD_ISSET(), FD_CLR */
39
#include <sys/wait.h> /* wait(), waitpid(), WIFEXITED(),
41
#include <sys/stat.h> /* struct stat, stat(), S_ISREG() */
42
#include <iso646.h> /* and, or, not */
43
#include <dirent.h> /* DIR, struct dirent, opendir(),
44
readdir(), closedir(), dirfd() */
45
#include <unistd.h> /* struct stat, stat(), S_ISREG(),
46
fcntl(), setuid(), setgid(),
47
F_GETFD, F_SETFD, FD_CLOEXEC,
48
access(), pipe(), fork(), close()
49
dup2, STDOUT_FILENO, _exit(),
50
execv(), write(), read(),
52
#include <fcntl.h> /* fcntl(), F_GETFD, F_SETFD,
54
#include <string.h> /* strsep, strlen(), strcpy(),
56
#include <errno.h> /* errno */
57
#include <argp.h> /* struct argp_option, struct
58
argp_state, struct argp,
59
argp_parse(), ARGP_ERR_UNKNOWN,
60
ARGP_KEY_END, ARGP_KEY_ARG, error_t */
61
#include <signal.h> /* struct sigaction, sigemptyset(),
62
sigaddset(), sigaction(),
63
sigprocmask(), SIG_BLOCK, SIGCHLD,
64
SIG_UNBLOCK, kill() */
65
#include <errno.h> /* errno, EBADF */
67
#define BUFFER_SIZE 256
69
const char *argp_program_version = "plugin-runner 1.0";
70
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
98
131
p->argv[p->argc] = NULL;
101
#define BUFFER_SIZE 256
103
const char *argp_program_version =
104
"plugbasedclient 0.9";
105
const char *argp_program_bug_address =
106
"<mandos@fukt.bsnet.se>";
108
"Mandos plugin runner -- Run Mandos plugins";
109
/* A description of the arguments we accept. */
110
static char args_doc[] = "";
135
* Based on the example in the GNU LibC manual chapter 13.13 "File
137
* *Note File Descriptor Flags:(libc)Descriptor Flags.
139
static int set_cloexec_flag(int fd)
141
int ret = fcntl(fd, F_GETFD, 0);
142
/* If reading the flags failed, return error indication now. */
146
/* Store modified flag word in the descriptor. */
147
return fcntl(fd, F_SETFD, ret | FD_CLOEXEC);
150
process *process_list = NULL;
152
/* Mark a process as completed when it exits, and save its exit
154
void handle_sigchld(__attribute__((unused)) int sig){
155
process *proc = process_list;
157
pid_t pid = wait(&status);
162
while(proc != NULL and proc->pid != pid){
166
/* Process not found in process list */
169
proc->status = status;
170
proc->completed = true;
173
bool print_out_password(const char *buffer, size_t length){
175
if(length>0 and buffer[length-1] == '\n'){
178
for(size_t written = 0; written < length; written += (size_t)ret){
179
ret = TEMP_FAILURE_RETRY(write(STDOUT_FILENO, buffer + written,
112
188
int main(int argc, char *argv[]){
113
char plugindir[] = "plugins.d";
114
size_t d_name_len, plugindir_len = sizeof(plugindir)-1;
189
const char *plugindir = "/lib/mandos/plugins.d";
116
192
struct dirent *dirst;
119
195
int ret, maxfd = 0;
120
process *process_list = NULL;
199
int exitstatus = EXIT_SUCCESS;
200
struct sigaction old_sigchld_action;
201
struct sigaction sigchld_action = { .sa_handler = handle_sigchld,
202
.sa_flags = SA_NOCLDSTOP };
203
char *plus_options = NULL;
204
char **plus_argv = NULL;
206
/* Establish a signal handler */
207
sigemptyset(&sigchld_action.sa_mask);
208
ret = sigaddset(&sigchld_action.sa_mask, SIGCHLD);
213
ret = sigaction(SIGCHLD, &sigchld_action, &old_sigchld_action);
122
219
/* The options we understand. */
123
220
struct argp_option options[] = {
124
221
{ .name = "global-options", .key = 'g',
125
.arg = "option[,option[,...]]", .flags = 0,
126
.doc = "Options effecting all plugins" },
222
.arg = "OPTION[,OPTION[,...]]",
223
.doc = "Options passed to all plugins" },
127
224
{ .name = "options-for", .key = 'o',
128
.arg = "plugin:option[,option[,...]]", .flags = 0,
129
.doc = "Options effecting only specified plugins" },
225
.arg = "PLUGIN:OPTION[,OPTION[,...]]",
226
.doc = "Options passed only to specified plugin" },
227
{ .name = "disable", .key = 'd',
229
.doc = "Disable a specific plugin", .group = 1 },
230
{ .name = "plugin-dir", .key = 128,
232
.doc = "Specify a different plugin directory", .group = 2 },
233
{ .name = "userid", .key = 129,
234
.arg = "ID", .flags = 0,
235
.doc = "User ID the plugins will run as", .group = 2 },
236
{ .name = "groupid", .key = 130,
237
.arg = "ID", .flags = 0,
238
.doc = "Group ID the plugins will run as", .group = 2 },
239
{ .name = "debug", .key = 131,
240
.doc = "Debug mode", .group = 3 },
133
244
error_t parse_opt (int key, char *arg, struct argp_state *state) {
134
/* Get the INPUT argument from `argp_parse', which we
135
know is a pointer to our arguments structure. */
245
/* Get the INPUT argument from `argp_parse', which we know is a
246
pointer to our plugin list pointer. */
136
247
plugin **plugins = state->input;
139
250
if (arg != NULL){
140
char *p = strtok(arg, ",");
142
addarguments(getplugin(NULL, plugins), p);
143
p = strtok(NULL, ",");
252
while((p = strsep(&arg, ",")) != NULL){
253
if(strcmp(p, "") == 0){
256
addargument(getplugin(NULL, plugins), p);
148
261
if (arg != NULL){
149
char *name = strtok(arg, ":");
150
char *p = strtok(NULL, ":");
153
addarguments(getplugin(name, plugins), p);
154
p = strtok(NULL, ",");
262
char *name = strsep(&arg, ":");
263
if(strcmp(name, "") == 0){
266
char *opt = strsep(&arg, ":");
267
if(strcmp(opt, "") == 0){
272
while((p = strsep(&opt, ",")) != NULL){
273
if(strcmp(p, "") == 0){
276
addargument(getplugin(name, plugins), p);
283
getplugin(arg, plugins)->disabled = true;
290
uid = (uid_t)strtol(arg, NULL, 10);
293
gid = (gid_t)strtol(arg, NULL, 10);
158
298
case ARGP_KEY_ARG:
299
if(plus_options != NULL or arg == NULL or arg[0] != '+'){
161
304
case ARGP_KEY_END:
169
312
plugin *plugin_list = NULL;
171
314
struct argp argp = { .options = options, .parser = parse_opt,
172
.args_doc = args_doc, .doc = doc };
174
argp_parse (&argp, argc, argv, 0, 0, &plugin_list);
176
/* for(plugin *p = plugin_list; p != NULL; p=p->next){ */
177
/* fprintf(stderr, "Plugin: %s has %d arguments\n", p->name ? p->name : "Global", p->argc); */
178
/* for(char **a = p->argv + 1; *a != NULL; a++){ */
179
/* fprintf(stderr, "\tArg: %s\n", *a); */
315
.args_doc = "[+PLUS_SEPARATED_OPTIONS]",
316
.doc = "Mandos plugin runner -- Run plugins" };
318
ret = argp_parse (&argp, argc, argv, 0, 0, &plugin_list);
319
if (ret == ARGP_ERR_UNKNOWN){
320
fprintf(stderr, "Unknown error while parsing arguments\n");
321
exitstatus = EXIT_FAILURE;
326
/* This is a mangled argument in the form of
327
"+--option+--other-option=parameter+--yet-another-option", etc */
328
/* Make new argc and argv vars, and call argp_parse() again. */
329
plus_options++; /* skip the first '+' character */
330
const char delims[] = "+";
333
plus_argv = malloc(sizeof(char*) * 2);
334
if(plus_argv == NULL){
336
exitstatus = EXIT_FAILURE;
339
plus_argv[0] = argv[0];
342
while((arg = strsep(&plus_options, delims)) != NULL){
344
plus_argv = realloc(plus_argv, sizeof(char *)
345
* ((unsigned int) new_argc + 1));
346
if(plus_argv == NULL){
348
exitstatus = EXIT_FAILURE;
351
plus_argv[new_argc-1] = arg;
352
plus_argv[new_argc] = NULL;
355
ret = argp_parse (&argp, new_argc, plus_argv, 0, 0, &plugin_list);
356
if (ret == ARGP_ERR_UNKNOWN){
357
fprintf(stderr, "Unknown error while parsing arguments\n");
358
exitstatus = EXIT_FAILURE;
364
for(plugin *p = plugin_list; p != NULL; p=p->next){
365
fprintf(stderr, "Plugin: %s has %d arguments\n",
366
p->name ? p->name : "Global", p->argc - 1);
367
for(char **a = p->argv; *a != NULL; a++){
368
fprintf(stderr, "\tArg: %s\n", *a);
185
383
dir = opendir(plugindir);
188
fprintf(stderr, "Can not open directory\n");
385
perror("Could not open plugin dir");
386
exitstatus = EXIT_FAILURE;
390
/* Set the FD_CLOEXEC flag on the directory, if possible */
392
int dir_fd = dirfd(dir);
394
ret = set_cloexec_flag(dir_fd);
396
perror("set_cloexec_flag");
397
exitstatus = EXIT_FAILURE;
195
406
dirst = readdir(dir);
197
408
// All directory entries have been processed
198
409
if(dirst == NULL){
412
exitstatus = EXIT_FAILURE;
202
418
d_name_len = strlen(dirst->d_name);
204
// Ignore dotfiles and backup files
205
if (dirst->d_name[0] == '.'
206
or dirst->d_name[d_name_len - 1] == '~'){
210
char *filename = malloc(d_name_len + plugindir_len + 2);
211
strcpy(filename, plugindir);
212
strcat(filename, "/");
213
strcat(filename, dirst->d_name);
217
if (S_ISREG(st.st_mode) and (access(filename, X_OK) == 0)){
218
// Starting a new process to be watched
219
process *new_process = malloc(sizeof(process));
226
new_process->pid = fork();
227
if(new_process->pid == 0){
228
/* this is the child process */
420
// Ignore dotfiles, backup files and other junk
422
bool bad_name = false;
424
const char const *bad_prefixes[] = { ".", "#", NULL };
426
const char const *bad_suffixes[] = { "~", "#", ".dpkg-new",
428
".dpkg-divert", NULL };
429
for(const char **pre = bad_prefixes; *pre != NULL; pre++){
430
size_t pre_len = strlen(*pre);
431
if((d_name_len >= pre_len)
432
and strncmp((dirst->d_name), *pre, pre_len) == 0){
434
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
435
" with bad prefix %s\n", dirst->d_name, *pre);
446
for(const char **suf = bad_suffixes; *suf != NULL; suf++){
447
size_t suf_len = strlen(*suf);
448
if((d_name_len >= suf_len)
449
and (strcmp((dirst->d_name)+d_name_len-suf_len, *suf)
452
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
453
" with bad suffix %s\n", dirst->d_name, *suf);
465
char *filename = malloc(d_name_len + strlen(plugindir) + 2);
466
if (filename == NULL){
470
strcpy(filename, plugindir); /* Spurious warning */
471
strcat(filename, "/"); /* Spurious warning */
472
strcat(filename, dirst->d_name); /* Spurious warning */
474
ret = stat(filename, &st);
481
if (not S_ISREG(st.st_mode) or (access(filename, X_OK) != 0)){
483
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
484
" with bad type or mode\n", filename);
489
if(getplugin(dirst->d_name, &plugin_list)->disabled){
491
fprintf(stderr, "Ignoring disabled plugin \"%s\"\n",
497
plugin *p = getplugin(dirst->d_name, &plugin_list);
499
/* Add global arguments to argument list for this plugin */
500
plugin *g = getplugin(NULL, &plugin_list);
501
for(char **a = g->argv + 1; *a != NULL; a++){
509
exitstatus = EXIT_FAILURE;
512
ret = set_cloexec_flag(pipefd[0]);
514
perror("set_cloexec_flag");
515
exitstatus = EXIT_FAILURE;
518
ret = set_cloexec_flag(pipefd[1]);
520
perror("set_cloexec_flag");
521
exitstatus = EXIT_FAILURE;
524
/* Block SIGCHLD until process is safely in process list */
525
ret = sigprocmask (SIG_BLOCK, &sigchld_action.sa_mask, NULL);
527
perror("sigprocmask");
528
exitstatus = EXIT_FAILURE;
531
// Starting a new process to be watched
535
exitstatus = EXIT_FAILURE;
539
/* this is the child process */
540
ret = sigaction(SIGCHLD, &old_sigchld_action, NULL);
545
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
547
perror("sigprocmask");
551
ret = dup2(pipefd[1], STDOUT_FILENO); /* replace our stdout */
558
/* If dir has no file descriptor, we could not set FD_CLOEXEC
559
above and must now close it manually here. */
230
close(pipefd[0]); /* close unused read end of pipe */
231
dup2(pipefd[1], STDOUT_FILENO); /* replace our stdout */
233
basename = strrchr(filename, '/');
234
if (basename == NULL){
239
plugin *p = getplugin(basename, &plugin_list);
241
plugin *g = getplugin(NULL, &plugin_list);
242
for(char **a = g->argv + 1; *a != NULL; a++){
245
if(execv(filename, p->argv) < 0){
252
close(pipefd[1]); /* close unused write end of pipe */
253
new_process->fd = pipefd[0];
254
new_process->buffer = malloc(BUFFER_SIZE);
255
if (new_process->buffer == NULL){
259
new_process->buffer_size = BUFFER_SIZE;
260
new_process->buffer_length = 0;
261
FD_SET(new_process->fd, &rfds_orig);
263
if (maxfd < new_process->fd){
264
maxfd = new_process->fd;
268
new_process->next = process_list;
269
process_list = new_process;
562
if(execv(filename, p->argv) < 0){
570
close(pipefd[1]); /* close unused write end of pipe */
571
process *new_process = malloc(sizeof(process));
572
if (new_process == NULL){
574
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
576
perror("sigprocmask");
578
exitstatus = EXIT_FAILURE;
582
*new_process = (struct process){ .pid = pid,
584
.next = process_list };
586
process_list = new_process;
587
/* Unblock SIGCHLD so signal handler can be run if this process
588
has already completed */
589
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
591
perror("sigprocmask");
592
exitstatus = EXIT_FAILURE;
596
FD_SET(new_process->fd, &rfds_all);
598
if (maxfd < new_process->fd){
599
maxfd = new_process->fd;
604
/* Free the plugin list */
605
for(plugin *next; plugin_list != NULL; plugin_list = next){
606
next = plugin_list->next;
607
free(plugin_list->argv);
275
if (process_list != NULL){
277
fd_set rfds = rfds_orig;
278
int select_ret = select(maxfd+1, &rfds, NULL, NULL, NULL);
279
if (select_ret == -1){
283
for(process *process_itr = process_list; process_itr != NULL;
284
process_itr = process_itr->next){
285
if(FD_ISSET(process_itr->fd, &rfds)){
286
if(process_itr->buffer_length + BUFFER_SIZE
287
> process_itr->buffer_size){
288
process_itr->buffer = realloc(process_itr->buffer,
289
process_itr->buffer_size
290
+ (size_t) BUFFER_SIZE);
291
if (process_itr->buffer == NULL){
295
process_itr->buffer_size += BUFFER_SIZE;
297
ret = read(process_itr->fd, process_itr->buffer
298
+ process_itr->buffer_length, BUFFER_SIZE);
300
/* Read error from this process; ignore it */
303
process_itr->buffer_length += (size_t) ret;
306
/* wait for process exit */
308
waitpid(process_itr->pid, &status, 0);
309
if(WIFEXITED(status) and WEXITSTATUS(status) == 0){
310
for(size_t written = 0;
311
written < process_itr->buffer_length;){
312
ret = write(STDOUT_FILENO,
313
process_itr->buffer + written,
314
process_itr->buffer_length - written);
319
written += (size_t)ret;
323
FD_CLR(process_itr->fd, &rfds_orig);
614
if (process_list == NULL){
615
fprintf(stderr, "No plugin processes started. Incorrect plugin"
620
fd_set rfds = rfds_all;
621
int select_ret = select(maxfd+1, &rfds, NULL, NULL, NULL);
622
if (select_ret == -1){
624
exitstatus = EXIT_FAILURE;
627
/* OK, now either a process completed, or something can be read
629
for(process *proc = process_list; proc ; proc = proc->next){
630
/* Is this process completely done? */
631
if(proc->eof and proc->completed){
632
/* Only accept the plugin output if it exited cleanly */
633
if(not WIFEXITED(proc->status)
634
or WEXITSTATUS(proc->status) != 0){
635
/* Bad exit by plugin */
637
if(WIFEXITED(proc->status)){
638
fprintf(stderr, "Plugin %u exited with status %d\n",
639
(unsigned int) (proc->pid),
640
WEXITSTATUS(proc->status));
641
} else if(WIFSIGNALED(proc->status)) {
642
fprintf(stderr, "Plugin %u killed by signal %d\n",
643
(unsigned int) (proc->pid),
644
WTERMSIG(proc->status));
645
} else if(WCOREDUMP(proc->status)){
646
fprintf(stderr, "Plugin %d dumped core\n",
647
(unsigned int) (proc->pid));
650
/* Remove the plugin */
651
FD_CLR(proc->fd, &rfds_all);
652
/* Block signal while modifying process_list */
653
ret = sigprocmask (SIG_BLOCK, &sigchld_action.sa_mask, NULL);
655
perror("sigprocmask");
656
exitstatus = EXIT_FAILURE;
659
/* Delete this process entry from the list */
660
if(process_list == proc){
661
/* First one - simple */
662
process_list = proc->next;
664
/* Second one or later */
665
for(process *p = process_list; p != NULL; p = p->next){
667
p->next = proc->next;
672
/* We are done modifying process list, so unblock signal */
673
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask,
676
perror("sigprocmask");
680
/* We deleted this process from the list, so we can't go
681
proc->next. Therefore, start over from the beginning of
685
/* This process exited nicely, so print its buffer */
687
bool bret = print_out_password(proc->buffer, proc->buffer_length);
689
perror("print_out_password");
690
exitstatus = EXIT_FAILURE;
694
/* This process has not completed. Does it have any output? */
695
if(proc->eof or not FD_ISSET(proc->fd, &rfds)){
696
/* This process had nothing to say at this time */
699
/* Before reading, make the process' data buffer large enough */
700
if(proc->buffer_length + BUFFER_SIZE > proc->buffer_size){
701
proc->buffer = realloc(proc->buffer, proc->buffer_size
702
+ (size_t) BUFFER_SIZE);
703
if (proc->buffer == NULL){
705
exitstatus = EXIT_FAILURE;
708
proc->buffer_size += BUFFER_SIZE;
710
/* Read from the process */
711
ret = read(proc->fd, proc->buffer + proc->buffer_length,
714
/* Read error from this process; ignore the error */
721
proc->buffer_length += (size_t) ret;
333
for(process *process_itr = process_list; process_itr != NULL;
334
process_itr = process_itr->next){
335
close(process_itr->fd);
336
kill(process_itr->pid, SIGTERM);
337
free(process_itr->buffer);
729
if(process_list == NULL or exitstatus != EXIT_SUCCESS){
730
/* Fallback if all plugins failed, none are found or an error occured */
732
fprintf(stderr, "Going to fallback mode using getpass(3)\n");
733
char *passwordbuffer = getpass("Password: ");
734
bret = print_out_password(passwordbuffer, strlen(passwordbuffer));
736
perror("print_out_password");
737
exitstatus = EXIT_FAILURE;
742
/* Restore old signal handler */
743
sigaction(SIGCHLD, &old_sigchld_action, NULL);
747
/* Free the plugin list */
748
for(plugin *next; plugin_list != NULL; plugin_list = next){
749
next = plugin_list->next;
750
free(plugin_list->argv);
758
/* Free the process list and kill the processes */
759
for(process *next; process_list != NULL; process_list = next){
760
next = process_list->next;
761
close(process_list->fd);
762
ret = kill(process_list->pid, SIGTERM);
763
if(ret == -1 and errno != ESRCH){
764
/* set-uid proccesses migth not get closed */
767
free(process_list->buffer);
771
/* Wait for any remaining child processes to terminate */