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
#include <stdio.h> /* popen(), fileno(), fprintf(),
25
stderr, STDOUT_FILENO */
42
26
#include <iso646.h> /* and, or, not */
27
#include <sys/types.h> /* DIR, opendir(), stat(), struct stat,
28
waitpid(), WIFEXITED(),
29
WEXITSTATUS(), wait() */
30
#include <sys/wait.h> /* wait() */
43
31
#include <dirent.h> /* DIR, struct dirent, opendir(),
44
readdir(), closedir(), dirfd() */
32
readdir(), closedir() */
33
#include <sys/stat.h> /* struct stat, stat(), S_ISREG() */
45
34
#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() */
36
#include <fcntl.h> /* fcntl() */
37
#include <stddef.h> /* NULL */
38
#include <stdlib.h> /* EXIT_FAILURE */
39
#include <sys/select.h> /* fd_set, select(), FD_ZERO(),
40
FD_SET(), FD_ISSET() */
41
#include <string.h> /* strlen(), strcpy(), strcat() */
42
#include <stdbool.h> /* true */
43
#include <sys/wait.h> /* waitpid(), WIFEXITED(),
55
45
#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>";
46
#include <argp.h> /* struct argp_option,
47
struct argp_state, struct argp,
52
typedef struct process{
77
61
typedef struct plugin{
78
62
char *name; /* can be NULL or any plugin name */
85
/* Variables used for running processes*/
92
volatile bool completed;
94
66
struct plugin *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){
69
plugin *getplugin(char *name, plugin **plugin_list){
70
for (plugin *p = *plugin_list; p != NULL; p = p->next){
104
71
if ((p->name == name)
105
72
or (p->name and name and (strcmp(p->name, name) == 0))){
206
/* Mark processes as completed when they exit, and save their exit
208
void handle_sigchld(__attribute__((unused)) int sig){
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 */
239
bool print_out_password(const char *buffer, size_t length){
241
if(length>0 and buffer[length-1] == '\n'){
244
for(size_t written = 0; written < length; written += (size_t)ret){
245
ret = TEMP_FAILURE_RETRY(write(STDOUT_FILENO, buffer + written,
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);
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;
284
static void free_plugin_list(void){
285
while(plugin_list != NULL){
286
free_plugin(plugin_list);
126
#define BUFFER_SIZE 256
128
const char *argp_program_version =
129
"plugbasedclient 0.9";
130
const char *argp_program_bug_address =
131
"<mandos@fukt.bsnet.se>";
290
133
int main(int argc, char *argv[]){
291
char *plugindir = NULL;
292
char *argfile = NULL;
134
const char *plugindir = "/conf/conf.d/mandos/plugins.d";
294
135
size_t d_name_len;
296
137
struct dirent *dirst;
299
140
int ret, maxfd = 0;
141
process *process_list = NULL;
302
142
bool debug = false;
303
143
int exitstatus = EXIT_SUCCESS;
304
struct sigaction old_sigchld_action;
305
struct sigaction sigchld_action = { .sa_handler = handle_sigchld,
306
.sa_flags = SA_NOCLDSTOP };
307
char **custom_argv = NULL;
310
/* Establish a signal handler */
311
sigemptyset(&sigchld_action.sa_mask);
312
ret = sigaddset(&sigchld_action.sa_mask, SIGCHLD);
315
exitstatus = EXIT_FAILURE;
318
ret = sigaction(SIGCHLD, &sigchld_action, &old_sigchld_action);
321
exitstatus = EXIT_FAILURE;
325
145
/* The options we understand. */
326
146
struct argp_option options[] = {
327
147
{ .name = "global-options", .key = 'g',
328
148
.arg = "OPTION[,OPTION[,...]]",
329
149
.doc = "Options passed to all plugins" },
330
{ .name = "global-envs", .key = 'e',
332
.doc = "Environment variable passed to all plugins" },
333
150
{ .name = "options-for", .key = 'o',
334
151
.arg = "PLUGIN:OPTION[,OPTION[,...]]",
335
152
.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" },
339
153
{ .name = "disable", .key = 'd',
341
155
.doc = "Disable a specific plugin", .group = 1 },
342
156
{ .name = "plugin-dir", .key = 128,
343
157
.arg = "DIRECTORY",
344
158
.doc = "Specify a different plugin directory", .group = 2 },
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 },
159
{ .name = "debug", .key = 129,
160
.doc = "Debug mode", .group = 3 },
359
error_t parse_opt (int key, char *arg, __attribute__((unused)) struct argp_state *state) {
360
/* Get the INPUT argument from `argp_parse', which we know is a
361
pointer to our plugin list pointer. */
164
error_t parse_opt (int key, char *arg, struct argp_state *state) {
165
/* Get the INPUT argument from `argp_parse', which we
166
know is a pointer to our plugin list pointer. */
167
plugin **plugins = state->input;
363
case 'g': /* --global-options */
366
while((p = strsep(&arg, ",")) != NULL){
370
if(not add_argument(getplugin(NULL), p)){
371
perror("add_argument");
372
return ARGP_ERR_UNKNOWN;
377
case 'e': /* --global-envs */
382
char *envdef = strdup(arg);
386
if(not add_environment(getplugin(NULL), envdef)){
387
perror("add_environment");
391
case 'o': /* --options-for */
393
char *p_name = strsep(&arg, ":");
394
if(p_name[0] == '\0'){
397
char *opt = strsep(&arg, ":");
403
while((p = strsep(&opt, ",")) != NULL){
407
if(not add_argument(getplugin(p_name), p)){
408
perror("add_argument");
409
return ARGP_ERR_UNKNOWN;
415
case 'f': /* --envs-for */
420
char *envdef = strchr(arg, ':');
424
char *p_name = strndup(arg, (size_t) (envdef-arg));
429
if(not add_environment(getplugin(p_name), envdef)){
430
perror("add_environment");
434
case 'd': /* --disable */
436
plugin *p = getplugin(arg);
438
return ARGP_ERR_UNKNOWN;
443
case 128: /* --plugin-dir */
444
plugindir = strdup(arg);
445
if(plugindir == NULL){
449
case 129: /* --config-file */
450
argfile = strdup(arg);
455
case 130: /* --userid */
456
uid = (uid_t)strtol(arg, NULL, 10);
458
case 131: /* --groupid */
459
gid = (gid_t)strtol(arg, NULL, 10);
461
case 132: /* --debug */
171
char *p = strtok(arg, ",");
173
addargument(getplugin(NULL, plugins), p);
174
p = strtok(NULL, ",");
180
char *name = strtok(arg, ":");
181
char *p = strtok(NULL, ":");
185
addargument(getplugin(name, plugins), p);
186
p = strtok(NULL, ",");
193
getplugin(arg, plugins)->disabled = true;
464
202
case ARGP_KEY_ARG:
465
fprintf(stderr, "Ignoring unknown argument \"%s\"\n", arg);
467
205
case ARGP_KEY_END:
213
plugin *plugin_list = NULL;
475
215
struct argp argp = { .options = options, .parser = parse_opt,
476
.args_doc = "[+PLUS_SEPARATED_OPTIONS]",
477
217
.doc = "Mandos plugin runner -- Run plugins" };
479
ret = argp_parse (&argp, argc, argv, 0, 0, NULL);
480
if (ret == ARGP_ERR_UNKNOWN){
481
fprintf(stderr, "Unknown error while parsing arguments\n");
482
exitstatus = EXIT_FAILURE;
486
/* Opens the configfile if aviable */
487
if (argfile == NULL){
488
conffp = fopen(AFILE, "r");
490
conffp = fopen(argfile, "r");
493
char *org_line = NULL;
494
char *p, *arg, *new_arg, *line;
497
const char whitespace_delims[] = " \r\t\f\v\n";
498
const char comment_delim[] = "#";
501
custom_argv = malloc(sizeof(char*) * 2);
502
if(custom_argv == NULL){
504
exitstatus = EXIT_FAILURE;
507
custom_argv[0] = argv[0];
508
custom_argv[1] = NULL;
510
/* for each line in the config file, strip whitespace and ignore commented text */
512
sret = getline(&org_line, &size, conffp);
518
arg = strsep(&line, comment_delim);
519
while((p = strsep(&arg, whitespace_delims)) != NULL){
526
exitstatus = EXIT_FAILURE;
532
custom_argv = realloc(custom_argv, sizeof(char *)
533
* ((unsigned int) custom_argc + 1));
534
if(custom_argv == NULL){
536
exitstatus = EXIT_FAILURE;
540
custom_argv[custom_argc-1] = new_arg;
541
custom_argv[custom_argc] = NULL;
546
/* Check for harmful errors and go to fallback. Other errors might
547
not affect opening plugins */
548
if (errno == EMFILE or errno == ENFILE or errno == ENOMEM){
550
exitstatus = EXIT_FAILURE;
554
/* If there was any arguments from configuration file,
555
pass them to parser as command arguments */
556
if(custom_argv != NULL){
557
ret = argp_parse (&argp, custom_argc, custom_argv, 0, 0, NULL);
558
if (ret == ARGP_ERR_UNKNOWN){
559
fprintf(stderr, "Unknown error while parsing arguments\n");
560
exitstatus = EXIT_FAILURE;
219
argp_parse (&argp, argc, argv, 0, 0, &plugin_list);
566
222
for(plugin *p = plugin_list; p != NULL; p=p->next){
676
ret = asprintf(&filename, "%s/%s", plugindir, dirst->d_name);
682
ret = stat(filename, &st);
301
char *filename = malloc(d_name_len + strlen(plugindir) + 2);
302
if (filename == NULL){
304
exitstatus =EXIT_FAILURE;
689
/* Ignore non-executable files */
307
strcpy(filename, plugindir);
308
strcat(filename, "/");
309
strcat(filename, dirst->d_name);
690
313
if (not S_ISREG(st.st_mode) or (access(filename, X_OK) != 0)){
692
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
315
fprintf(stderr, "Ignoring plugin dir entry name \"%s\""
693
316
" with bad type or mode\n", filename);
699
plugin *p = getplugin(dirst->d_name);
320
if(getplugin(dirst->d_name, &plugin_list)->disabled){
707
fprintf(stderr, "Ignoring disabled plugin \"%s\"\n",
322
fprintf(stderr, "Ignoring disabled plugin \"%s\"",
714
/* Add global arguments to argument list for this plugin */
715
plugin *g = getplugin(NULL);
717
for(char **a = g->argv + 1; *a != NULL; a++){
718
if(not add_argument(p, *a)){
719
perror("add_argument");
722
/* Add global environment variables */
723
for(char **e = g->environ; *e != NULL; e++){
724
if(not add_environment(p, *e)){
725
perror("add_environment");
730
/* If this plugin has any environment variables, we will call
731
using execve and need to duplicate the environment from this
733
if(p->environ[0] != NULL){
734
for(char **e = environ; *e != NULL; e++){
735
char *copy = strdup(*e);
740
if(not add_environment(p, copy)){
741
perror("add_environment");
327
// Starting a new process to be watched
747
329
ret = pipe(pipefd);
750
exitstatus = EXIT_FAILURE;
753
/* Ask OS to automatic close the pipe on exec */
754
ret = set_cloexec_flag(pipefd[0]);
756
perror("set_cloexec_flag");
757
exitstatus = EXIT_FAILURE;
760
ret = set_cloexec_flag(pipefd[1]);
762
perror("set_cloexec_flag");
763
exitstatus = EXIT_FAILURE;
766
/* Block SIGCHLD until process is safely in process list */
767
ret = sigprocmask (SIG_BLOCK, &sigchld_action.sa_mask, NULL);
769
perror("sigprocmask");
770
exitstatus = EXIT_FAILURE;
773
// Starting a new process to be watched
334
plugin *p = getplugin(dirst->d_name, &plugin_list);
336
/* Add global arguments to argument list for this plugin */
337
plugin *g = getplugin(NULL, &plugin_list);
338
for(char **a = g->argv + 1; *a != NULL; a++){
774
342
pid_t pid = fork();
777
exitstatus = EXIT_FAILURE;
781
344
/* this is the child process */
782
ret = sigaction(SIGCHLD, &old_sigchld_action, NULL);
787
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
789
perror("sigprocmask");
793
ret = dup2(pipefd[1], STDOUT_FILENO); /* replace our stdout */
346
close(pipefd[0]); /* close unused read end of pipe */
347
dup2(pipefd[1], STDOUT_FILENO); /* replace our stdout */
800
/* If dir has no file descriptor, we could not set FD_CLOEXEC
801
above and must now close it manually here. */
804
if(p->environ[0] == NULL){
805
if(execv(filename, p->argv) < 0){
810
if(execve(filename, p->argv, p->environ) < 0){
352
if(execv(filename, p->argv) < 0){
818
close(pipefd[1]); /* Close unused write end of pipe */
820
plugin *new_plugin = getplugin(dirst->d_name);
821
if (new_plugin == NULL){
823
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
825
perror("sigprocmask");
827
exitstatus = EXIT_FAILURE;
831
new_plugin->pid = pid;
832
new_plugin->fd = pipefd[0];
834
/* Unblock SIGCHLD so signal handler can be run if this process
835
has already completed */
836
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
838
perror("sigprocmask");
839
exitstatus = EXIT_FAILURE;
843
FD_SET(new_plugin->fd, &rfds_all);
845
if (maxfd < new_plugin->fd){
846
maxfd = new_plugin->fd;
359
close(pipefd[1]); /* close unused write end of pipe */
360
process *new_process = malloc(sizeof(process));
361
if (new_process == NULL){
363
exitstatus = EXIT_FAILURE;
367
new_process->fd = pipefd[0];
368
new_process->buffer = malloc(BUFFER_SIZE);
369
if (new_process->buffer == NULL){
371
exitstatus = EXIT_FAILURE;
374
new_process->buffer_size = BUFFER_SIZE;
375
new_process->buffer_length = 0;
376
FD_SET(new_process->fd, &rfds_all);
378
if (maxfd < new_process->fd){
379
maxfd = new_process->fd;
383
new_process->next = process_list;
384
process_list = new_process;
854
for(plugin *p = plugin_list; p != NULL; p = p->next){
389
if (process_list != NULL){
391
fd_set rfds = rfds_all;
392
int select_ret = select(maxfd+1, &rfds, NULL, NULL, NULL);
393
if (select_ret == -1){
397
for(process *process_itr = process_list; process_itr != NULL;
398
process_itr = process_itr->next){
399
if(FD_ISSET(process_itr->fd, &rfds)){
400
if(process_itr->buffer_length + BUFFER_SIZE
401
> process_itr->buffer_size){
402
process_itr->buffer = realloc(process_itr->buffer,
403
process_itr->buffer_size
404
+ (size_t) BUFFER_SIZE);
405
if (process_itr->buffer == NULL){
409
process_itr->buffer_size += BUFFER_SIZE;
411
ret = read(process_itr->fd, process_itr->buffer
412
+ process_itr->buffer_length, BUFFER_SIZE);
414
/* Read error from this process; ignore it */
417
process_itr->buffer_length += (size_t) ret;
420
/* wait for process exit */
422
waitpid(process_itr->pid, &status, 0);
423
if(WIFEXITED(status) and WEXITSTATUS(status) == 0){
424
for(size_t written = 0;
425
written < process_itr->buffer_length;){
426
ret = write(STDOUT_FILENO,
427
process_itr->buffer + written,
428
process_itr->buffer_length - written);
433
written += (size_t)ret;
437
FD_CLR(process_itr->fd, &rfds_all);
447
for(process *process_itr = process_list; process_itr != NULL;
448
process_itr = process_itr->next){
449
close(process_itr->fd);
450
kill(process_itr->pid, SIGTERM);
451
free(process_itr->buffer);
859
fprintf(stderr, "No plugin processes started. Incorrect plugin"
865
/* Main loop while running plugins exist */
867
fd_set rfds = rfds_all;
868
int select_ret = select(maxfd+1, &rfds, NULL, NULL, NULL);
869
if (select_ret == -1){
871
exitstatus = EXIT_FAILURE;
874
/* OK, now either a process completed, or something can be read
876
for(plugin *proc = plugin_list; proc != NULL; proc = proc->next){
877
/* Is this process completely done? */
878
if(proc->eof and proc->completed){
879
/* Only accept the plugin output if it exited cleanly */
880
if(not WIFEXITED(proc->status)
881
or WEXITSTATUS(proc->status) != 0){
882
/* Bad exit by plugin */
885
if(WIFEXITED(proc->status)){
886
fprintf(stderr, "Plugin %u exited with status %d\n",
887
(unsigned int) (proc->pid),
888
WEXITSTATUS(proc->status));
889
} else if(WIFSIGNALED(proc->status)) {
890
fprintf(stderr, "Plugin %u killed by signal %d\n",
891
(unsigned int) (proc->pid),
892
WTERMSIG(proc->status));
893
} else if(WCOREDUMP(proc->status)){
894
fprintf(stderr, "Plugin %d dumped core\n",
895
(unsigned int) (proc->pid));
899
/* Remove the plugin */
900
FD_CLR(proc->fd, &rfds_all);
902
/* Block signal while modifying process_list */
903
ret = sigprocmask(SIG_BLOCK, &sigchld_action.sa_mask, NULL);
905
perror("sigprocmask");
906
exitstatus = EXIT_FAILURE;
910
/* We are done modifying process list, so unblock signal */
911
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask,
914
perror("sigprocmask");
915
exitstatus = EXIT_FAILURE;
919
if(plugin_list == NULL){
925
/* This process exited nicely, so print its buffer */
927
bool bret = print_out_password(proc->buffer,
928
proc->buffer_length);
930
perror("print_out_password");
931
exitstatus = EXIT_FAILURE;
936
/* This process has not completed. Does it have any output? */
937
if(proc->eof or not FD_ISSET(proc->fd, &rfds)){
938
/* This process had nothing to say at this time */
941
/* Before reading, make the process' data buffer large enough */
942
if(proc->buffer_length + BUFFER_SIZE > proc->buffer_size){
943
proc->buffer = realloc(proc->buffer, proc->buffer_size
944
+ (size_t) BUFFER_SIZE);
945
if (proc->buffer == NULL){
947
exitstatus = EXIT_FAILURE;
950
proc->buffer_size += BUFFER_SIZE;
952
/* Read from the process */
953
ret = read(proc->fd, proc->buffer + proc->buffer_length,
956
/* Read error from this process; ignore the error */
963
proc->buffer_length += (size_t) ret;
971
if(plugin_list == NULL or exitstatus != EXIT_SUCCESS){
972
/* Fallback if all plugins failed, none are found or an error
975
fprintf(stderr, "Going to fallback mode using getpass(3)\n");
976
char *passwordbuffer = getpass("Password: ");
977
bret = print_out_password(passwordbuffer, strlen(passwordbuffer));
979
perror("print_out_password");
980
exitstatus = EXIT_FAILURE;
984
/* Restore old signal handler */
985
ret = sigaction(SIGCHLD, &old_sigchld_action, NULL);
988
exitstatus = EXIT_FAILURE;
991
if(custom_argv != NULL){
992
for(char **arg = custom_argv+1; *arg != NULL; arg++){
1002
/* Free the process list and kill the processes */
1003
for(plugin *p = plugin_list; p != NULL; p = p->next){
1006
ret = kill(p->pid, SIGTERM);
1007
if(ret == -1 and errno != ESRCH){
1008
/* Set-uid proccesses might not get closed */
1014
/* Wait for any remaining child processes to terminate */
1018
if(errno != ECHILD){
1027
464
return exitstatus;