52
52
#include <fcntl.h> /* fcntl(), F_GETFD, F_SETFD,
54
#include <string.h> /* strsep, strlen(), strcpy(),
54
#include <string.h> /* strsep, strlen(), asprintf() */
56
55
#include <errno.h> /* errno */
57
56
#include <argp.h> /* struct argp_option, struct
58
57
argp_state, struct argp,
59
58
argp_parse(), ARGP_ERR_UNKNOWN,
60
ARGP_KEY_END, ARGP_KEY_ARG, error_t */
59
ARGP_KEY_END, ARGP_KEY_ARG,
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61
#include <signal.h> /* struct sigaction, sigemptyset(),
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62
sigaddset(), sigaction(),
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63
sigprocmask(), SIG_BLOCK, SIGCHLD,
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65
#include <errno.h> /* errno, EBADF */
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67
#define BUFFER_SIZE 256
68
#define CONFFILE "/conf/conf.d/mandos/client.conf"
70
const char *argp_program_version = "mandos-client 1.0";
69
#define PDIR "/lib/mandos/plugins.d"
70
#define AFILE "/conf/conf.d/mandos/plugin-runner.conf"
72
const char *argp_program_version = "plugin-runner 1.0";
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73
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
75
typedef struct process{
77
typedef struct plugin{
78
char *name; /* can be NULL or any plugin name */
85
/* Variables used for running processes*/
79
89
size_t buffer_size;
80
90
size_t buffer_length;
87
typedef struct plugin{
88
char *name; /* can be NULL or any plugin name */
92
volatile bool completed;
92
94
struct plugin *next;
95
static plugin *getplugin(char *name, plugin **plugin_list){
96
for (plugin *p = *plugin_list; p != NULL; p = p->next){
97
static plugin *plugin_list = NULL;
99
/* Gets a existing plugin based on name,
100
or if none is found, creates a new one */
101
static plugin *getplugin(char *name){
102
/* Check for exiting plugin with that name */
103
for (plugin *p = plugin_list; p != NULL; p = p->next){
97
104
if ((p->name == name)
98
105
or (p->name and name and (strcmp(p->name, name) == 0))){
102
109
/* Create a new plugin */
103
110
plugin *new_plugin = malloc(sizeof(plugin));
104
111
if (new_plugin == NULL){
108
new_plugin->name = name;
114
char *copy_name = NULL;
116
copy_name = strdup(name);
117
if(copy_name == NULL){
122
*new_plugin = (plugin) { .name = copy_name,
125
.next = plugin_list };
109
127
new_plugin->argv = malloc(sizeof(char *) * 2);
110
128
if (new_plugin->argv == NULL){
114
new_plugin->argv[0] = name;
133
new_plugin->argv[0] = copy_name;
115
134
new_plugin->argv[1] = NULL;
116
new_plugin->argc = 1;
117
new_plugin->disabled = false;
118
new_plugin->next = *plugin_list;
136
new_plugin->environ = malloc(sizeof(char *));
137
if(new_plugin->environ == NULL){
139
free(new_plugin->argv);
143
new_plugin->environ[0] = NULL;
119
145
/* Append the new plugin to the list */
120
*plugin_list = new_plugin;
146
plugin_list = new_plugin;
121
147
return new_plugin;
124
static void addargument(plugin *p, char *arg){
125
p->argv[p->argc] = arg;
126
p->argv = realloc(p->argv, sizeof(char *) * (size_t)(p->argc + 2));
127
if (p->argv == NULL){
132
p->argv[p->argc] = NULL;
150
/* Helper function for add_argument and add_environment */
151
static bool add_to_char_array(const char *new, char ***array,
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/* Resize the pointed-to array to hold one more pointer */
154
*array = realloc(*array, sizeof(char *)
155
* (size_t) ((*len) + 2));
160
/* Make a copy of the new string */
161
char *copy = strdup(new);
165
/* Insert the copy */
166
(*array)[*len] = copy;
168
/* Add a new terminating NULL pointer to the last element */
169
(*array)[*len] = NULL;
173
/* Add to a plugin's argument vector */
174
static bool add_argument(plugin *p, const char *arg){
178
return add_to_char_array(arg, &(p->argv), &(p->argc));
181
/* Add to a plugin's environment */
182
static bool add_environment(plugin *p, const char *def){
186
return add_to_char_array(def, &(p->environ), &(p->envc));
148
202
return fcntl(fd, F_SETFD, ret | FD_CLOEXEC);
151
process *process_list = NULL;
153
/* Mark a process as completed when it exits, and save its exit
206
/* Mark processes as completed when they exit, and save their exit
155
208
void handle_sigchld(__attribute__((unused)) int sig){
156
process *proc = process_list;
158
pid_t pid = wait(&status);
163
while(proc != NULL and proc->pid != pid){
167
/* Process not found in process list */
170
proc->status = status;
171
proc->completed = true;
210
plugin *proc = plugin_list;
212
pid_t pid = waitpid(-1, &status, WNOHANG);
214
/* Only still running child processes */
218
if (errno != ECHILD){
221
/* No child processes */
225
/* A child exited, find it in process_list */
226
while(proc != NULL and proc->pid != pid){
230
/* Process not found in process list */
233
proc->status = status;
234
proc->completed = true;
238
/* Prints out a password to stdout */
174
239
bool print_out_password(const char *buffer, size_t length){
176
241
if(length>0 and buffer[length-1] == '\n'){
189
char ** addcustomargument(char **argv, int *argc, char *arg){
254
/* Removes and free a plugin from the plugin list */
255
static void free_plugin(plugin *plugin_node){
257
for(char **arg = plugin_node->argv; *arg != NULL; arg++){
260
free(plugin_node->argv);
261
for(char **env = plugin_node->environ; *env != NULL; env++){
264
free(plugin_node->environ);
265
free(plugin_node->buffer);
193
argv = malloc(sizeof(char*) * 2);
267
/* Removes the plugin from the singly-linked list */
268
if(plugin_node == plugin_list){
269
/* First one - simple */
270
plugin_list = plugin_list->next;
272
/* Second one or later */
273
for(plugin *p = plugin_list; p != NULL; p = p->next){
274
if(p->next == plugin_node){
275
p->next = plugin_node->next;
197
argv[0] = NULL; /* Will be set to argv[0] in main before parsing */
201
argv = realloc(argv, sizeof(char *)
202
* ((unsigned int) *argc + 1));
284
static void free_plugin_list(void){
285
while(plugin_list != NULL){
286
free_plugin(plugin_list);
211
290
int main(int argc, char *argv[]){
212
const char *plugindir = "/conf/conf.d/mandos/plugins.d";
213
const char *conffile = CONFFILE;
291
char *plugindir = NULL;
292
char *argfile = NULL;
215
294
size_t d_name_len;
246
327
{ .name = "global-options", .key = 'g',
247
328
.arg = "OPTION[,OPTION[,...]]",
248
329
.doc = "Options passed to all plugins" },
330
{ .name = "global-envs", .key = 'e',
332
.doc = "Environment variable passed to all plugins" },
249
333
{ .name = "options-for", .key = 'o',
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334
.arg = "PLUGIN:OPTION[,OPTION[,...]]",
251
335
.doc = "Options passed only to specified plugin" },
336
{ .name = "envs-for", .key = 'f',
337
.arg = "PLUGIN:ENV=value",
338
.doc = "Environment variable passed to specified plugin" },
252
339
{ .name = "disable", .key = 'd',
254
341
.doc = "Disable a specific plugin", .group = 1 },
255
342
{ .name = "plugin-dir", .key = 128,
256
343
.arg = "DIRECTORY",
257
344
.doc = "Specify a different plugin directory", .group = 2 },
258
{ .name = "userid", .key = 129,
259
.arg = "ID", .flags = 0,
260
.doc = "User ID the plugins will run as", .group = 2 },
261
{ .name = "groupid", .key = 130,
262
.arg = "ID", .flags = 0,
263
.doc = "Group ID the plugins will run as", .group = 2 },
264
{ .name = "debug", .key = 131,
265
.doc = "Debug mode", .group = 3 },
345
{ .name = "config-file", .key = 129,
347
.doc = "Specify a different configuration file", .group = 2 },
348
{ .name = "userid", .key = 130,
349
.arg = "ID", .flags = 0,
350
.doc = "User ID the plugins will run as", .group = 3 },
351
{ .name = "groupid", .key = 131,
352
.arg = "ID", .flags = 0,
353
.doc = "Group ID the plugins will run as", .group = 3 },
354
{ .name = "debug", .key = 132,
355
.doc = "Debug mode", .group = 4 },
269
error_t parse_opt (int key, char *arg, struct argp_state *state) {
359
error_t parse_opt (int key, char *arg, __attribute__((unused))
360
struct argp_state *state) {
270
361
/* Get the INPUT argument from `argp_parse', which we know is a
271
362
pointer to our plugin list pointer. */
272
plugin **plugins = state->input;
364
case 'g': /* --global-options */
275
365
if (arg != NULL){
277
367
while((p = strsep(&arg, ",")) != NULL){
278
368
if(p[0] == '\0'){
281
addargument(getplugin(NULL, plugins), p);
371
if(not add_argument(getplugin(NULL), p)){
372
perror("add_argument");
373
return ARGP_ERR_UNKNOWN;
378
case 'e': /* --global-envs */
383
char *envdef = strdup(arg);
387
if(not add_environment(getplugin(NULL), envdef)){
388
perror("add_environment");
392
case 'o': /* --options-for */
286
393
if (arg != NULL){
287
char *name = strsep(&arg, ":");
394
char *p_name = strsep(&arg, ":");
395
if(p_name[0] == '\0'){
291
398
char *opt = strsep(&arg, ":");
298
405
if(p[0] == '\0'){
301
addargument(getplugin(name, plugins), p);
408
if(not add_argument(getplugin(p_name), p)){
409
perror("add_argument");
410
return ARGP_ERR_UNKNOWN;
416
case 'f': /* --envs-for */
421
char *envdef = strchr(arg, ':');
425
char *p_name = strndup(arg, (size_t) (envdef-arg));
430
if(not add_environment(getplugin(p_name), envdef)){
431
perror("add_environment");
435
case 'd': /* --disable */
307
436
if (arg != NULL){
308
getplugin(arg, plugins)->disabled = true;
437
plugin *p = getplugin(arg);
439
return ARGP_ERR_UNKNOWN;
444
case 128: /* --plugin-dir */
445
plugindir = strdup(arg);
446
if(plugindir == NULL){
450
case 129: /* --config-file */
451
argfile = strdup(arg);
456
case 130: /* --userid */
315
457
uid = (uid_t)strtol(arg, NULL, 10);
459
case 131: /* --groupid */
318
460
gid = (gid_t)strtol(arg, NULL, 10);
462
case 132: /* --debug */
323
465
case ARGP_KEY_ARG:
324
fprintf(stderr, "Ignoring unknown argument \"%s\"\n", arg);
466
fprintf(stderr, "Ignoring unknown argument \"%s\"\n", arg);
326
468
case ARGP_KEY_END:
334
plugin *plugin_list = NULL;
336
476
struct argp argp = { .options = options, .parser = parse_opt,
337
477
.args_doc = "[+PLUS_SEPARATED_OPTIONS]",
338
478
.doc = "Mandos plugin runner -- Run plugins" };
340
ret = argp_parse (&argp, argc, argv, 0, 0, &plugin_list);
480
ret = argp_parse (&argp, argc, argv, 0, 0, NULL);
341
481
if (ret == ARGP_ERR_UNKNOWN){
342
482
fprintf(stderr, "Unknown error while parsing arguments\n");
343
483
exitstatus = EXIT_FAILURE;
347
conffp = fopen(conffile, "r");
487
/* Opens the configfile if aviable */
488
if (argfile == NULL){
489
conffp = fopen(AFILE, "r");
491
conffp = fopen(argfile, "r");
348
493
if(conffp != NULL){
349
494
char *org_line = NULL;
495
char *p, *arg, *new_arg, *line;
352
char *p, *arg, *new_arg, *line;
353
498
const char whitespace_delims[] = " \r\t\f\v\n";
354
499
const char comment_delim[] = "#";
502
custom_argv = malloc(sizeof(char*) * 2);
503
if(custom_argv == NULL){
505
exitstatus = EXIT_FAILURE;
508
custom_argv[0] = argv[0];
509
custom_argv[1] = NULL;
511
/* for each line in the config file, strip whitespace and ignore
357
514
sret = getline(&org_line, &size, conffp);
368
525
new_arg = strdup(p);
369
custom_argv = addcustomargument(custom_argv, &custom_argc, new_arg);
370
if (custom_argv == NULL){
371
perror("addcustomargument");
372
exitstatus = EXIT_FAILURE;
528
exitstatus = EXIT_FAILURE;
534
custom_argv = realloc(custom_argv, sizeof(char *)
535
* ((unsigned int) custom_argc + 1));
536
if(custom_argv == NULL){
538
exitstatus = EXIT_FAILURE;
542
custom_argv[custom_argc-1] = new_arg;
543
custom_argv[custom_argc] = NULL;
379
/* check for harmfull errors */
548
/* Check for harmful errors and go to fallback. Other errors might
549
not affect opening plugins */
380
550
if (errno == EMFILE or errno == ENFILE or errno == ENOMEM){
382
552
exitstatus = EXIT_FAILURE;
556
/* If there was any arguments from configuration file,
557
pass them to parser as command arguments */
387
558
if(custom_argv != NULL){
388
custom_argv[0] = argv[0];
389
ret = argp_parse (&argp, custom_argc, custom_argv, 0, 0, &plugin_list);
559
ret = argp_parse (&argp, custom_argc, custom_argv, 0, 0, NULL);
390
560
if (ret == ARGP_ERR_UNKNOWN){
391
561
fprintf(stderr, "Unknown error while parsing arguments\n");
392
562
exitstatus = EXIT_FAILURE;
401
571
for(char **a = p->argv; *a != NULL; a++){
402
572
fprintf(stderr, "\tArg: %s\n", *a);
574
fprintf(stderr, "...and %u environment variables\n", p->envc);
575
for(char **a = p->environ; *a != NULL; a++){
576
fprintf(stderr, "\t%s\n", *a);
581
/* Strip permissions down to nobody */
407
582
ret = setuid(uid);
409
584
perror("setuid");
414
588
perror("setgid");
591
if (plugindir == NULL){
594
dir = opendir(plugindir);
417
dir = opendir(plugindir);
419
598
perror("Could not open plugin dir");
420
599
exitstatus = EXIT_FAILURE;
424
603
/* Set the FD_CLOEXEC flag on the directory, if possible */
531
plugin *p = getplugin(dirst->d_name, &plugin_list);
533
716
/* Add global arguments to argument list for this plugin */
534
plugin *g = getplugin(NULL, &plugin_list);
535
for(char **a = g->argv + 1; *a != NULL; a++){
717
plugin *g = getplugin(NULL);
719
for(char **a = g->argv + 1; *a != NULL; a++){
720
if(not add_argument(p, *a)){
721
perror("add_argument");
724
/* Add global environment variables */
725
for(char **e = g->environ; *e != NULL; e++){
726
if(not add_environment(p, *e)){
727
perror("add_environment");
732
/* If this plugin has any environment variables, we will call
733
using execve and need to duplicate the environment from this
735
if(p->environ[0] != NULL){
736
for(char **e = environ; *e != NULL; e++){
737
char *copy = strdup(*e);
742
if(not add_environment(p, copy)){
743
perror("add_environment");
540
749
ret = pipe(pipefd);
543
752
exitstatus = EXIT_FAILURE;
755
/* Ask OS to automatic close the pipe on exec */
546
756
ret = set_cloexec_flag(pipefd[0]);
548
758
perror("set_cloexec_flag");
549
759
exitstatus = EXIT_FAILURE;
552
762
ret = set_cloexec_flag(pipefd[1]);
554
764
perror("set_cloexec_flag");
555
765
exitstatus = EXIT_FAILURE;
558
768
/* Block SIGCHLD until process is safely in process list */
559
769
ret = sigprocmask (SIG_BLOCK, &sigchld_action.sa_mask, NULL);
561
771
perror("sigprocmask");
562
772
exitstatus = EXIT_FAILURE;
565
775
// Starting a new process to be watched
566
776
pid_t pid = fork();
569
779
exitstatus = EXIT_FAILURE;
573
783
/* this is the child process */
593
803
above and must now close it manually here. */
596
if(execv(filename, p->argv) < 0){
806
if(p->environ[0] == NULL){
807
if(execv(filename, p->argv) < 0){
812
if(execve(filename, p->argv, p->environ) < 0){
820
close(pipefd[1]); /* Close unused write end of pipe */
604
close(pipefd[1]); /* close unused write end of pipe */
605
process *new_process = malloc(sizeof(process));
606
if (new_process == NULL){
822
plugin *new_plugin = getplugin(dirst->d_name);
823
if (new_plugin == NULL){
608
825
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
610
perror("sigprocmask");
827
perror("sigprocmask");
612
829
exitstatus = EXIT_FAILURE;
616
*new_process = (struct process){ .pid = pid,
618
.next = process_list };
620
process_list = new_process;
833
new_plugin->pid = pid;
834
new_plugin->fd = pipefd[0];
621
836
/* Unblock SIGCHLD so signal handler can be run if this process
622
837
has already completed */
623
838
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
625
840
perror("sigprocmask");
626
841
exitstatus = EXIT_FAILURE;
630
FD_SET(new_process->fd, &rfds_all);
632
if (maxfd < new_process->fd){
633
maxfd = new_process->fd;
638
/* Free the plugin list */
639
for(plugin *next; plugin_list != NULL; plugin_list = next){
640
next = plugin_list->next;
641
free(plugin_list->argv);
845
FD_SET(new_plugin->fd, &rfds_all);
847
if (maxfd < new_plugin->fd){
848
maxfd = new_plugin->fd;
648
if (process_list == NULL){
649
fprintf(stderr, "No plugin processes started. Incorrect plugin"
856
for(plugin *p = plugin_list; p != NULL; p = p->next){
861
fprintf(stderr, "No plugin processes started. Incorrect plugin"
867
/* Main loop while running plugins exist */
654
869
fd_set rfds = rfds_all;
655
870
int select_ret = select(maxfd+1, &rfds, NULL, NULL, NULL);
656
871
if (select_ret == -1){
657
872
perror("select");
658
873
exitstatus = EXIT_FAILURE;
661
876
/* OK, now either a process completed, or something can be read
662
877
from one of them */
663
for(process *proc = process_list; proc ; proc = proc->next){
878
for(plugin *proc = plugin_list; proc != NULL; proc = proc->next){
664
879
/* Is this process completely done? */
665
880
if(proc->eof and proc->completed){
666
881
/* Only accept the plugin output if it exited cleanly */
667
882
if(not WIFEXITED(proc->status)
668
883
or WEXITSTATUS(proc->status) != 0){
669
884
/* Bad exit by plugin */
671
887
if(WIFEXITED(proc->status)){
672
888
fprintf(stderr, "Plugin %u exited with status %d\n",
681
897
(unsigned int) (proc->pid));
684
901
/* Remove the plugin */
685
902
FD_CLR(proc->fd, &rfds_all);
686
904
/* Block signal while modifying process_list */
687
ret = sigprocmask (SIG_BLOCK, &sigchld_action.sa_mask, NULL);
905
ret = sigprocmask(SIG_BLOCK, &sigchld_action.sa_mask, NULL);
689
907
perror("sigprocmask");
690
908
exitstatus = EXIT_FAILURE;
693
/* Delete this process entry from the list */
694
if(process_list == proc){
695
/* First one - simple */
696
process_list = proc->next;
698
/* Second one or later */
699
for(process *p = process_list; p != NULL; p = p->next){
701
p->next = proc->next;
706
912
/* We are done modifying process list, so unblock signal */
707
913
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask,
710
916
perror("sigprocmask");
714
/* We deleted this process from the list, so we can't go
715
proc->next. Therefore, start over from the beginning of
917
exitstatus = EXIT_FAILURE;
921
if(plugin_list == NULL){
719
927
/* This process exited nicely, so print its buffer */
721
bool bret = print_out_password(proc->buffer, proc->buffer_length);
929
bool bret = print_out_password(proc->buffer,
930
proc->buffer_length);
723
932
perror("print_out_password");
724
933
exitstatus = EXIT_FAILURE;
728
938
/* This process has not completed. Does it have any output? */
729
939
if(proc->eof or not FD_ISSET(proc->fd, &rfds)){
730
940
/* This process had nothing to say at this time */
792
1004
/* Free the process list and kill the processes */
793
for(process *next; process_list != NULL; process_list = next){
794
next = process_list->next;
795
close(process_list->fd);
796
ret = kill(process_list->pid, SIGTERM);
797
if(ret == -1 and errno != ESRCH){
798
/* set-uid proccesses migth not get closed */
1005
for(plugin *p = plugin_list; p != NULL; p = p->next){
1008
ret = kill(p->pid, SIGTERM);
1009
if(ret == -1 and errno != ESRCH){
1010
/* Set-uid proccesses might not get closed */
801
free(process_list->buffer);
805
1016
/* Wait for any remaining child processes to terminate */