21
21
* Contact the authors at <mandos@fukt.bsnet.se>.
24
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), getline(),
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() */
24
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY() */
26
#include <stdio.h> /* popen(), fileno(), fprintf(),
27
stderr, STDOUT_FILENO */
42
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() */
43
34
#include <dirent.h> /* DIR, struct dirent, opendir(),
44
readdir(), closedir(), dirfd() */
35
readdir(), closedir() */
36
#include <sys/stat.h> /* struct stat, stat(), S_ISREG() */
45
37
#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(), asprintf() */
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(),
55
48
#include <errno.h> /* errno */
56
#include <argp.h> /* struct argp_option, struct
57
argp_state, struct argp,
58
argp_parse(), ARGP_ERR_UNKNOWN,
59
ARGP_KEY_END, ARGP_KEY_ARG,
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
#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";
73
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
75
typedef struct plugin{
76
char *name; /* can be NULL or any plugin name */
83
/* Variables used for running processes*/
49
#include <argp.h> /* struct argp_option,
50
struct argp_state, struct argp,
55
typedef struct process{
87
59
size_t buffer_size;
88
60
size_t buffer_length;
90
volatile bool completed;
67
typedef struct plugin{
68
char *name; /* can be NULL or any plugin name */
92
72
struct plugin *next;
95
static plugin *plugin_list = NULL;
97
/* Gets an existing plugin based on name,
98
or if none is found, creates a new one */
99
static plugin *getplugin(char *name){
100
/* Check for exiting plugin with that name */
101
for (plugin *p = plugin_list; p != NULL; p = p->next){
75
plugin *getplugin(char *name, plugin **plugin_list){
76
for (plugin *p = *plugin_list; p != NULL; p = p->next){
102
77
if ((p->name == name)
103
78
or (p->name and name and (strcmp(p->name, name) == 0))){
107
82
/* Create a new plugin */
108
83
plugin *new_plugin = malloc(sizeof(plugin));
109
84
if (new_plugin == NULL){
112
char *copy_name = NULL;
114
copy_name = strdup(name);
115
if(copy_name == NULL){
120
*new_plugin = (plugin) { .name = copy_name,
123
.next = plugin_list };
88
new_plugin->name = name;
125
89
new_plugin->argv = malloc(sizeof(char *) * 2);
126
90
if (new_plugin->argv == NULL){
131
new_plugin->argv[0] = copy_name;
94
new_plugin->argv[0] = name;
132
95
new_plugin->argv[1] = NULL;
134
new_plugin->environ = malloc(sizeof(char *));
135
if(new_plugin->environ == NULL){
137
free(new_plugin->argv);
141
new_plugin->environ[0] = NULL;
97
new_plugin->disabled = false;
98
new_plugin->next = *plugin_list;
143
99
/* Append the new plugin to the list */
144
plugin_list = new_plugin;
100
*plugin_list = new_plugin;
145
101
return new_plugin;
148
/* Helper function for add_argument and add_environment */
149
static bool add_to_char_array(const char *new, char ***array,
151
/* Resize the pointed-to array to hold one more pointer */
152
*array = realloc(*array, sizeof(char *)
153
* (size_t) ((*len) + 2));
158
/* Make a copy of the new string */
159
char *copy = strdup(new);
163
/* Insert the copy */
164
(*array)[*len] = copy;
166
/* Add a new terminating NULL pointer to the last element */
167
(*array)[*len] = NULL;
171
/* Add to a plugin's argument vector */
172
static bool add_argument(plugin *p, const char *arg){
176
return add_to_char_array(arg, &(p->argv), &(p->argc));
179
/* Add to a plugin's environment */
180
static bool add_environment(plugin *p, const char *def, bool replace){
184
/* namelen = length of name of environment variable */
185
size_t namelen = (size_t)(strchrnul(def, '=') - def);
186
/* Search for this environment variable */
187
for(char **e = p->environ; *e != NULL; e++){
188
if(strncmp(*e, def, namelen + 1) == 0){
189
/* It already exists */
191
char *new = realloc(*e, strlen(def) + 1);
201
return add_to_char_array(def, &(p->environ), &(p->envc));
104
void addargument(plugin *p, char *arg){
105
p->argv[p->argc] = arg;
106
p->argv = realloc(p->argv, sizeof(char *) * (size_t)(p->argc + 2));
107
if (p->argv == NULL){
112
p->argv[p->argc] = NULL;
216
128
return fcntl(fd, F_SETFD, ret | FD_CLOEXEC);
220
/* Mark processes as completed when they exit, and save their exit
131
#define BUFFER_SIZE 256
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
222
static void handle_sigchld(__attribute__((unused)) int sig){
224
plugin *proc = plugin_list;
226
pid_t pid = waitpid(-1, &status, WNOHANG);
228
/* Only still running child processes */
232
if (errno != ECHILD){
235
/* No child processes */
239
/* A child exited, find it in process_list */
240
while(proc != NULL and proc->pid != pid){
244
/* Process not found in process list */
247
proc->status = status;
248
proc->completed = true;
252
/* Prints out a password to stdout */
253
static bool print_out_password(const char *buffer, size_t length){
255
for(size_t written = 0; written < length; written += (size_t)ret){
256
ret = TEMP_FAILURE_RETRY(write(STDOUT_FILENO, buffer + written,
265
/* Removes and free a plugin from the plugin list */
266
static void free_plugin(plugin *plugin_node){
268
for(char **arg = plugin_node->argv; *arg != NULL; arg++){
271
free(plugin_node->argv);
272
for(char **env = plugin_node->environ; *env != NULL; env++){
275
free(plugin_node->environ);
276
free(plugin_node->buffer);
278
/* Removes the plugin from the singly-linked list */
279
if(plugin_node == plugin_list){
280
/* First one - simple */
281
plugin_list = plugin_list->next;
283
/* Second one or later */
284
for(plugin *p = plugin_list; p != NULL; p = p->next){
285
if(p->next == plugin_node){
286
p->next = plugin_node->next;
295
static void free_plugin_list(void){
296
while(plugin_list != NULL){
297
free_plugin(plugin_list);
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;
301
155
int main(int argc, char *argv[]){
302
char *plugindir = NULL;
303
char *argfile = NULL;
156
const char *plugindir = "/conf/conf.d/mandos/plugins.d";
305
157
size_t d_name_len;
307
159
struct dirent *dirst;
338
188
{ .name = "global-options", .key = 'g',
339
189
.arg = "OPTION[,OPTION[,...]]",
340
190
.doc = "Options passed to all plugins" },
341
{ .name = "global-env", .key = 'G',
343
.doc = "Environment variable passed to all plugins" },
344
191
{ .name = "options-for", .key = 'o',
345
192
.arg = "PLUGIN:OPTION[,OPTION[,...]]",
346
193
.doc = "Options passed only to specified plugin" },
347
{ .name = "env-for", .key = 'E',
348
.arg = "PLUGIN:ENV=value",
349
.doc = "Environment variable passed to specified plugin" },
350
194
{ .name = "disable", .key = 'd',
352
196
.doc = "Disable a specific plugin", .group = 1 },
353
{ .name = "enable", .key = 'e',
355
.doc = "Enable a specific plugin", .group = 1 },
356
197
{ .name = "plugin-dir", .key = 128,
357
198
.arg = "DIRECTORY",
358
199
.doc = "Specify a different plugin directory", .group = 2 },
359
{ .name = "config-file", .key = 129,
361
.doc = "Specify a different configuration file", .group = 2 },
362
{ .name = "userid", .key = 130,
363
.arg = "ID", .flags = 0,
364
.doc = "User ID the plugins will run as", .group = 3 },
365
{ .name = "groupid", .key = 131,
366
.arg = "ID", .flags = 0,
367
.doc = "Group ID the plugins will run as", .group = 3 },
368
{ .name = "debug", .key = 132,
369
.doc = "Debug mode", .group = 4 },
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 },
373
error_t parse_opt (int key, char *arg, __attribute__((unused))
374
struct argp_state *state) {
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;
376
case 'g': /* --global-options */
379
while((p = strsep(&arg, ",")) != NULL){
383
if(not add_argument(getplugin(NULL), p)){
384
perror("add_argument");
385
return ARGP_ERR_UNKNOWN;
390
case 'G': /* --global-env */
394
if(not add_environment(getplugin(NULL), arg, true)){
395
perror("add_environment");
398
case 'o': /* --options-for */
400
char *p_name = strsep(&arg, ":");
401
if(p_name[0] == '\0' or arg == NULL){
404
char *opt = strsep(&arg, ":");
405
if(opt[0] == '\0' or opt == NULL){
409
while((p = strsep(&opt, ",")) != NULL){
413
if(not add_argument(getplugin(p_name), p)){
414
perror("add_argument");
415
return ARGP_ERR_UNKNOWN;
420
case 'E': /* --env-for */
425
char *envdef = strchr(arg, ':');
430
if(not add_environment(getplugin(arg), envdef+1, true)){
431
perror("add_environment");
435
case 'd': /* --disable */
437
plugin *p = getplugin(arg);
439
return ARGP_ERR_UNKNOWN;
444
case 'e': /* --enable */
446
plugin *p = getplugin(arg);
448
return ARGP_ERR_UNKNOWN;
453
case 128: /* --plugin-dir */
455
plugindir = strdup(arg);
456
if(plugindir == NULL){
460
case 129: /* --config-file */
461
/* This is already done by parse_opt_config_file() */
463
case 130: /* --userid */
218
char *p = strtok(arg, ",");
220
addargument(getplugin(NULL, plugins), p);
221
p = strtok(NULL, ",");
227
char *name = strtok(arg, ":");
228
char *p = strtok(NULL, ":");
232
addargument(getplugin(name, plugins), p);
233
p = strtok(NULL, ",");
240
getplugin(arg, plugins)->disabled = true;
464
247
uid = (uid_t)strtol(arg, NULL, 10);
466
case 131: /* --groupid */
467
250
gid = (gid_t)strtol(arg, NULL, 10);
469
case 132: /* --debug */
472
255
case ARGP_KEY_ARG:
473
/* Cryptsetup always passes an argument, which is an empty
474
string if "none" was specified in /etc/crypttab. So if
475
argument was empty, we ignore it silently. */
477
fprintf(stderr, "Ignoring unknown argument \"%s\"\n", arg);
483
return ARGP_ERR_UNKNOWN;
488
/* This option parser is the same as parse_opt() above, except it
489
ignores everything but the --config-file option. */
490
error_t parse_opt_config_file (int key, char *arg,
491
__attribute__((unused))
492
struct argp_state *state) {
494
case 'g': /* --global-options */
495
case 'G': /* --global-env */
496
case 'o': /* --options-for */
497
case 'E': /* --env-for */
498
case 'd': /* --disable */
499
case 'e': /* --enable */
500
case 128: /* --plugin-dir */
502
case 129: /* --config-file */
504
argfile = strdup(arg);
509
case 130: /* --userid */
510
case 131: /* --groupid */
511
case 132: /* --debug */
516
return ARGP_ERR_UNKNOWN;
521
struct argp argp = { .options = options,
522
.parser = parse_opt_config_file,
256
if(plus_options != NULL or arg == NULL or arg[0] != '+'){
264
return ARGP_ERR_UNKNOWN;
269
plugin *plugin_list = NULL;
271
struct argp argp = { .options = options, .parser = parse_opt,
272
.args_doc = "[+PLUS_SEPARATED_OPTIONS]",
524
273
.doc = "Mandos plugin runner -- Run plugins" };
526
/* Parse using the parse_opt_config_file in order to get the custom
527
config file location, if any. */
528
ret = argp_parse (&argp, argc, argv, ARGP_IN_ORDER, 0, NULL);
529
if (ret == ARGP_ERR_UNKNOWN){
530
fprintf(stderr, "Unknown error while parsing arguments\n");
531
exitstatus = EXIT_FAILURE;
535
/* Reset to the normal argument parser */
536
argp.parser = parse_opt;
538
/* Open the configfile if available */
539
if (argfile == NULL){
540
conffp = fopen(AFILE, "r");
542
conffp = fopen(argfile, "r");
545
char *org_line = NULL;
546
char *p, *arg, *new_arg, *line;
549
const char whitespace_delims[] = " \r\t\f\v\n";
550
const char comment_delim[] = "#";
553
custom_argv = malloc(sizeof(char*) * 2);
554
if(custom_argv == NULL){
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){
555
287
perror("malloc");
556
288
exitstatus = EXIT_FAILURE;
559
custom_argv[0] = argv[0];
560
custom_argv[1] = NULL;
562
/* for each line in the config file, strip whitespace and ignore
565
sret = getline(&org_line, &size, conffp);
571
arg = strsep(&line, comment_delim);
572
while((p = strsep(&arg, whitespace_delims)) != NULL){
579
exitstatus = EXIT_FAILURE;
585
custom_argv = realloc(custom_argv, sizeof(char *)
586
* ((unsigned int) custom_argc + 1));
587
if(custom_argv == NULL){
589
exitstatus = EXIT_FAILURE;
593
custom_argv[custom_argc-1] = new_arg;
594
custom_argv[custom_argc] = NULL;
599
/* Check for harmful errors and go to fallback. Other errors might
600
not affect opening plugins */
601
if (errno == EMFILE or errno == ENFILE or errno == ENOMEM){
603
exitstatus = EXIT_FAILURE;
607
/* If there was any arguments from configuration file,
608
pass them to parser as command arguments */
609
if(custom_argv != NULL){
610
ret = argp_parse (&argp, custom_argc, custom_argv, ARGP_IN_ORDER,
612
if (ret == ARGP_ERR_UNKNOWN){
613
fprintf(stderr, "Unknown error while parsing arguments\n");
614
exitstatus = EXIT_FAILURE;
619
/* Parse actual command line arguments, to let them override the
621
ret = argp_parse (&argp, argc, argv, ARGP_IN_ORDER, 0, NULL);
622
if (ret == ARGP_ERR_UNKNOWN){
623
fprintf(stderr, "Unknown error while parsing arguments\n");
624
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);
851
480
perror("sigprocmask");
852
481
_exit(EXIT_FAILURE);
855
ret = dup2(pipefd[1], STDOUT_FILENO); /* replace our stdout */
483
dup2(pipefd[1], STDOUT_FILENO); /* replace our stdout */
861
485
if(dirfd(dir) < 0){
862
486
/* If dir has no file descriptor, we could not set FD_CLOEXEC
863
487
above and must now close it manually here. */
866
if(p->environ[0] == NULL){
867
if(execv(filename, p->argv) < 0){
872
if(execve(filename, p->argv, p->environ) < 0){
490
if(execv(filename, p->argv) < 0){
880
close(pipefd[1]); /* Close unused write end of pipe */
882
plugin *new_plugin = getplugin(dirst->d_name);
883
if (new_plugin == NULL){
498
close(pipefd[1]); /* close unused write end of pipe */
499
process *new_process = malloc(sizeof(process));
500
if (new_process == NULL){
885
502
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
887
perror("sigprocmask");
504
perror("sigprocmask");
889
506
exitstatus = EXIT_FAILURE;
893
new_plugin->pid = pid;
894
new_plugin->fd = pipefd[0];
510
*new_process = (struct process){ .pid = pid,
512
.next = process_list };
514
process_list = new_process;
896
515
/* Unblock SIGCHLD so signal handler can be run if this process
897
516
has already completed */
898
517
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
900
519
perror("sigprocmask");
901
520
exitstatus = EXIT_FAILURE;
905
FD_SET(new_plugin->fd, &rfds_all);
907
if (maxfd < new_plugin->fd){
908
maxfd = new_plugin->fd;
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);
916
for(plugin *p = plugin_list; p != NULL; p = p->next){
921
fprintf(stderr, "No plugin processes started. Incorrect plugin"
542
if (process_list == NULL){
543
fprintf(stderr, "No plugin processes started, exiting\n");
544
exitstatus = EXIT_FAILURE;
927
/* Main loop while running plugins exist */
929
548
fd_set rfds = rfds_all;
930
549
int select_ret = select(maxfd+1, &rfds, NULL, NULL, NULL);
931
550
if (select_ret == -1){
932
551
perror("select");
933
552
exitstatus = EXIT_FAILURE;
936
555
/* OK, now either a process completed, or something can be read
937
556
from one of them */
938
for(plugin *proc = plugin_list; proc != NULL;){
557
for(process *proc = process_list; proc ; proc = proc->next){
939
558
/* Is this process completely done? */
940
559
if(proc->eof and proc->completed){
941
560
/* Only accept the plugin output if it exited cleanly */
942
561
if(not WIFEXITED(proc->status)
943
562
or WEXITSTATUS(proc->status) != 0){
944
563
/* Bad exit by plugin */
947
565
if(WIFEXITED(proc->status)){
948
fprintf(stderr, "Plugin %u exited with status %d\n",
949
(unsigned int) (proc->pid),
950
WEXITSTATUS(proc->status));
566
fprintf(stderr, "Plugin %d exited with status %d\n",
567
proc->pid, WEXITSTATUS(proc->status));
951
568
} else if(WIFSIGNALED(proc->status)) {
952
fprintf(stderr, "Plugin %u killed by signal %d\n",
953
(unsigned int) (proc->pid),
954
WTERMSIG(proc->status));
569
fprintf(stderr, "Plugin %d killed by signal %d\n",
570
proc->pid, WTERMSIG(proc->status));
955
571
} else if(WCOREDUMP(proc->status)){
956
fprintf(stderr, "Plugin %d dumped core\n",
957
(unsigned int) (proc->pid));
572
fprintf(stderr, "Plugin %d dumped core\n", proc->pid);
961
575
/* Remove the plugin */
962
576
FD_CLR(proc->fd, &rfds_all);
964
577
/* Block signal while modifying process_list */
965
ret = sigprocmask(SIG_BLOCK, &sigchld_action.sa_mask, NULL);
578
ret = sigprocmask (SIG_BLOCK, &sigchld_action.sa_mask, NULL);
967
580
perror("sigprocmask");
968
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;
972
597
/* We are done modifying process list, so unblock signal */
973
598
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask,
976
601
perror("sigprocmask");
977
exitstatus = EXIT_FAILURE;
981
if(plugin_list == NULL){
985
plugin *next_plugin = proc->next;
605
/* We deleted this process from the list, so we can't go
606
proc->next. Therefore, start over from the beginning of
991
610
/* This process exited nicely, so print its buffer */
993
bool bret = print_out_password(proc->buffer,
994
proc->buffer_length);
996
perror("print_out_password");
997
exitstatus = EXIT_FAILURE;
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;
1002
625
/* This process has not completed. Does it have any output? */
1003
626
if(proc->eof or not FD_ISSET(proc->fd, &rfds)){
1004
627
/* This process had nothing to say at this time */
1008
630
/* Before reading, make the process' data buffer large enough */