21
21
* Contact the authors at <mandos@fukt.bsnet.se>.
24
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY() */
24
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), getline(),
26
26
#include <stddef.h> /* size_t, NULL */
27
27
#include <stdlib.h> /* malloc(), exit(), EXIT_FAILURE,
28
28
EXIT_SUCCESS, realloc() */
52
52
#include <fcntl.h> /* fcntl(), F_GETFD, F_SETFD,
54
#include <string.h> /* strtok, 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,
61
61
#include <signal.h> /* struct sigaction, sigemptyset(),
62
62
sigaddset(), sigaction(),
63
63
sigprocmask(), SIG_BLOCK, SIGCHLD,
98
106
/* Create a new plugin */
99
107
plugin *new_plugin = malloc(sizeof(plugin));
100
108
if (new_plugin == NULL){
104
new_plugin->name = name;
111
char *copy_name = NULL;
113
copy_name = strdup(name);
114
if(copy_name == NULL){
119
*new_plugin = (plugin) { .name = copy_name,
123
.next = *plugin_list };
105
125
new_plugin->argv = malloc(sizeof(char *) * 2);
106
126
if (new_plugin->argv == NULL){
110
new_plugin->argv[0] = name;
131
new_plugin->argv[0] = copy_name;
111
132
new_plugin->argv[1] = NULL;
112
new_plugin->argc = 1;
113
new_plugin->disabled = false;
114
new_plugin->next = *plugin_list;
134
new_plugin->environ = malloc(sizeof(char *));
135
if(new_plugin->environ == NULL){
137
free(new_plugin->argv);
141
new_plugin->environ[0] = NULL;
115
142
/* Append the new plugin to the list */
116
143
*plugin_list = new_plugin;
117
144
return new_plugin;
120
static void addargument(plugin *p, char *arg){
121
p->argv[p->argc] = arg;
122
p->argv = realloc(p->argv, sizeof(char *) * (size_t)(p->argc + 2));
123
if (p->argv == NULL){
128
p->argv[p->argc] = NULL;
147
/* Helper function for add_argument and add_environment */
148
static bool add_to_char_array(const char *new, char ***array,
150
/* Resize the pointed-to array to hold one more pointer */
151
*array = realloc(*array, sizeof(char *)
152
* (size_t) ((*len) + 2));
157
/* Make a copy of the new string */
158
char *copy = strdup(new);
162
/* Insert the copy */
163
(*array)[*len] = copy;
165
/* Add a new terminating NULL pointer to the last element */
166
(*array)[*len] = NULL;
170
/* Add to a plugin's argument vector */
171
static bool add_argument(plugin *p, const char *arg){
175
return add_to_char_array(arg, &(p->argv), &(p->argc));
178
/* Add to a plugin's environment */
179
static bool add_environment(plugin *p, const char *def){
183
return add_to_char_array(def, &(p->environ), &(p->envc));
132
188
* Based on the example in the GNU LibC manual chapter 13.13 "File
144
200
return fcntl(fd, F_SETFD, ret | FD_CLOEXEC);
147
const char *argp_program_version = "plugbasedclient 0.9";
148
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
150
203
process *process_list = NULL;
152
/* Mark a process as completed when it exits, and save its exit
205
/* Mark processes as completed when they exit, and save their exit
154
207
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;
209
process *proc = process_list;
211
pid_t pid = waitpid(-1, &status, WNOHANG);
213
/* Only still running child processes */
217
if (errno != ECHILD){
220
/* No child processes */
224
/* A child exited, find it in process_list */
225
while(proc != NULL and proc->pid != pid){
229
/* Process not found in process list */
232
proc->status = status;
233
proc->completed = true;
237
bool print_out_password(const char *buffer, size_t length){
239
if(length>0 and buffer[length-1] == '\n'){
242
for(size_t written = 0; written < length; written += (size_t)ret){
243
ret = TEMP_FAILURE_RETRY(write(STDOUT_FILENO, buffer + written,
252
static void free_plugin_list(plugin *plugin_list){
253
for(plugin *next; plugin_list != NULL; plugin_list = next){
254
next = plugin_list->next;
255
for(char **arg = plugin_list->argv; *arg != NULL; arg++){
258
free(plugin_list->argv);
259
for(char **env = plugin_list->environ; *env != NULL; env++){
262
free(plugin_list->environ);
173
267
int main(int argc, char *argv[]){
174
const char *plugindir = "/conf/conf.d/mandos/plugins.d";
268
char *plugindir = NULL;
269
char *argfile = NULL;
175
271
size_t d_name_len;
177
273
struct dirent *dirst;
185
281
struct sigaction old_sigchld_action;
186
282
struct sigaction sigchld_action = { .sa_handler = handle_sigchld,
187
283
.sa_flags = SA_NOCLDSTOP };
188
char *plus_options = NULL;
189
char **plus_argv = NULL;
284
char **custom_argv = NULL;
191
287
/* Establish a signal handler */
192
288
sigemptyset(&sigchld_action.sa_mask);
193
289
ret = sigaddset(&sigchld_action.sa_mask, SIGCHLD);
195
291
perror("sigaddset");
292
exitstatus = EXIT_FAILURE;
198
295
ret = sigaction(SIGCHLD, &sigchld_action, &old_sigchld_action);
200
297
perror("sigaction");
298
exitstatus = EXIT_FAILURE;
204
302
/* The options we understand. */
206
304
{ .name = "global-options", .key = 'g',
207
305
.arg = "OPTION[,OPTION[,...]]",
208
306
.doc = "Options passed to all plugins" },
307
{ .name = "global-envs", .key = 'e',
309
.doc = "Environment variable passed to all plugins" },
209
310
{ .name = "options-for", .key = 'o',
210
311
.arg = "PLUGIN:OPTION[,OPTION[,...]]",
211
312
.doc = "Options passed only to specified plugin" },
313
{ .name = "envs-for", .key = 'f',
314
.arg = "PLUGIN:ENV=value",
315
.doc = "Environment variable passed to specified plugin" },
212
316
{ .name = "disable", .key = 'd',
214
318
.doc = "Disable a specific plugin", .group = 1 },
215
319
{ .name = "plugin-dir", .key = 128,
216
320
.arg = "DIRECTORY",
217
321
.doc = "Specify a different plugin directory", .group = 2 },
218
{ .name = "userid", .key = 129,
219
.arg = "ID", .flags = 0,
220
.doc = "User ID the plugins will run as", .group = 2 },
221
{ .name = "groupid", .key = 130,
222
.arg = "ID", .flags = 0,
223
.doc = "Group ID the plugins will run as", .group = 2 },
224
{ .name = "debug", .key = 131,
225
.doc = "Debug mode", .group = 3 },
322
{ .name = "config-file", .key = 129,
324
.doc = "Specify a different configuration file", .group = 2 },
325
{ .name = "userid", .key = 130,
326
.arg = "ID", .flags = 0,
327
.doc = "User ID the plugins will run as", .group = 3 },
328
{ .name = "groupid", .key = 131,
329
.arg = "ID", .flags = 0,
330
.doc = "Group ID the plugins will run as", .group = 3 },
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{ .name = "debug", .key = 132,
332
.doc = "Debug mode", .group = 4 },
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342
if (arg != NULL){
236
char *p = strtok(arg, ",");
238
addargument(getplugin(NULL, plugins), p);
239
p = strtok(NULL, ",");
344
while((p = strsep(&arg, ",")) != NULL){
348
if(not add_argument(getplugin(NULL, plugins), p)){
349
perror("add_argument");
350
return ARGP_ERR_UNKNOWN;
360
char *envdef = strdup(arg);
364
if(not add_environment(getplugin(NULL, plugins), envdef)){
365
perror("add_environment");
244
370
if (arg != NULL){
245
char *name = strtok(arg, ":");
246
char *p = strtok(NULL, ":");
250
addargument(getplugin(name, plugins), p);
251
p = strtok(NULL, ",");
371
char *p_name = strsep(&arg, ":");
372
if(p_name[0] == '\0'){
375
char *opt = strsep(&arg, ":");
381
while((p = strsep(&opt, ",")) != NULL){
385
if(not add_argument(getplugin(p_name, plugins), p)){
386
perror("add_argument");
387
return ARGP_ERR_UNKNOWN;
398
char *envdef = strchr(arg, ':');
402
char *p_name = strndup(arg, (size_t) (envdef-arg));
407
if(not add_environment(getplugin(p_name, plugins), envdef)){
408
perror("add_environment");
257
413
if (arg != NULL){
258
getplugin(arg, plugins)->disabled = true;
414
plugin *p = getplugin(arg, plugins);
416
return ARGP_ERR_UNKNOWN;
422
plugindir = strdup(arg);
423
if(plugindir == NULL){
428
argfile = strdup(arg);
265
434
uid = (uid_t)strtol(arg, NULL, 10);
268
437
gid = (gid_t)strtol(arg, NULL, 10);
273
442
case ARGP_KEY_ARG:
274
if(plus_options != NULL or arg == NULL or arg[0] != '+'){
443
fprintf(stderr, "Ignoring unknown argument \"%s\"\n", arg);
279
445
case ARGP_KEY_END:
293
459
ret = argp_parse (&argp, argc, argv, 0, 0, &plugin_list);
294
460
if (ret == ARGP_ERR_UNKNOWN){
295
perror("argp_parse");
461
fprintf(stderr, "Unknown error while parsing arguments\n");
296
462
exitstatus = EXIT_FAILURE;
466
if (argfile == NULL){
467
conffp = fopen(AFILE, "r");
469
conffp = fopen(argfile, "r");
301
/* This is a mangled argument in the form of
302
"+--option+--other-option=parameter+--yet-another-option", etc */
303
/* Make new argc and argv vars, and call argp_parse() again. */
304
plus_options++; /* skip the first '+' character */
305
const char delims[] = "+";
308
plus_argv = malloc(sizeof(char*) * 2);
309
if(plus_argv == NULL){
473
char *org_line = NULL;
474
char *p, *arg, *new_arg, *line;
477
const char whitespace_delims[] = " \r\t\f\v\n";
478
const char comment_delim[] = "#";
481
custom_argv = malloc(sizeof(char*) * 2);
482
if(custom_argv == NULL){
310
483
perror("malloc");
311
484
exitstatus = EXIT_FAILURE;
314
plus_argv[0] = argv[0];
316
arg = strtok(plus_options, delims); /* Get first argument */
319
plus_argv = realloc(plus_argv, sizeof(char *)
320
* ((unsigned int) new_argc + 1));
321
if(plus_argv == NULL){
323
exitstatus = EXIT_FAILURE;
326
plus_argv[new_argc-1] = arg;
327
plus_argv[new_argc] = NULL;
328
arg = strtok(NULL, delims); /* Get next argument */
330
ret = argp_parse (&argp, new_argc, plus_argv, 0, 0, &plugin_list);
487
custom_argv[0] = argv[0];
488
custom_argv[1] = NULL;
491
sret = getline(&org_line, &size, conffp);
497
arg = strsep(&line, comment_delim);
498
while((p = strsep(&arg, whitespace_delims)) != NULL){
505
exitstatus = EXIT_FAILURE;
511
custom_argv = realloc(custom_argv, sizeof(char *)
512
* ((unsigned int) custom_argc + 1));
513
if(custom_argv == NULL){
515
exitstatus = EXIT_FAILURE;
519
custom_argv[custom_argc-1] = new_arg;
520
custom_argv[custom_argc] = NULL;
525
/* Check for harmful errors and go to fallback. Other errors might
526
not affect opening plugins */
527
if (errno == EMFILE or errno == ENFILE or errno == ENOMEM){
529
exitstatus = EXIT_FAILURE;
534
if(custom_argv != NULL){
535
ret = argp_parse (&argp, custom_argc, custom_argv, 0, 0, &plugin_list);
331
536
if (ret == ARGP_ERR_UNKNOWN){
332
perror("argp_parse");
537
fprintf(stderr, "Unknown error while parsing arguments\n");
333
538
exitstatus = EXIT_FAILURE;
440
char *filename = malloc(d_name_len + strlen(plugindir) + 2);
441
if (filename == NULL){
443
exitstatus = EXIT_FAILURE;
655
ret = asprintf(&filename, "%s/%s", plugindir, dirst->d_name);
446
strcpy(filename, plugindir); /* Spurious warning */
447
strcat(filename, "/"); /* Spurious warning */
448
strcat(filename, dirst->d_name); /* Spurious warning */
450
661
ret = stat(filename, &st);
453
exitstatus = EXIT_FAILURE;
457
668
if (not S_ISREG(st.st_mode) or (access(filename, X_OK) != 0)){
473
plugin *p = getplugin(dirst->d_name, &plugin_list);
475
691
/* Add global arguments to argument list for this plugin */
476
692
plugin *g = getplugin(NULL, &plugin_list);
477
for(char **a = g->argv + 1; *a != NULL; a++){
694
for(char **a = g->argv + 1; *a != NULL; a++){
695
if(not add_argument(p, *a)){
696
perror("add_argument");
699
/* Add global environment variables */
700
for(char **e = g->environ; *e != NULL; e++){
701
if(not add_environment(p, *e)){
702
perror("add_environment");
707
/* If this plugin has any environment variables, we will call
708
using execve and need to duplicate the environment from this
710
if(p->environ[0] != NULL){
711
for(char **e = environ; *e != NULL; e++){
712
char *copy = strdup(*e);
717
if(not add_environment(p, copy)){
718
perror("add_environment");
482
724
ret = pipe(pipefd);
485
727
exitstatus = EXIT_FAILURE;
488
730
ret = set_cloexec_flag(pipefd[0]);
490
732
perror("set_cloexec_flag");
491
733
exitstatus = EXIT_FAILURE;
494
736
ret = set_cloexec_flag(pipefd[1]);
496
738
perror("set_cloexec_flag");
497
739
exitstatus = EXIT_FAILURE;
500
742
/* Block SIGCHLD until process is safely in process list */
501
743
ret = sigprocmask (SIG_BLOCK, &sigchld_action.sa_mask, NULL);
503
745
perror("sigprocmask");
504
746
exitstatus = EXIT_FAILURE;
507
749
// Starting a new process to be watched
508
750
pid_t pid = fork();
753
exitstatus = EXIT_FAILURE;
510
757
/* this is the child process */
511
758
ret = sigaction(SIGCHLD, &old_sigchld_action, NULL);
575
/* Free the plugin list */
576
for(plugin *next; plugin_list != NULL; plugin_list = next){
577
next = plugin_list->next;
578
free(plugin_list->argv);
829
free_plugin_list(plugin_list);
585
835
if (process_list == NULL){
586
fprintf(stderr, "No plugin processes started, exiting\n");
587
exitstatus = EXIT_FAILURE;
836
fprintf(stderr, "No plugin processes started. Incorrect plugin"
590
840
while(process_list){
591
841
fd_set rfds = rfds_all;
606
856
/* Bad exit by plugin */
608
858
if(WIFEXITED(proc->status)){
609
fprintf(stderr, "Plugin %d exited with status %d\n",
610
proc->pid, WEXITSTATUS(proc->status));
859
fprintf(stderr, "Plugin %u exited with status %d\n",
860
(unsigned int) (proc->pid),
861
WEXITSTATUS(proc->status));
611
862
} else if(WIFSIGNALED(proc->status)) {
612
fprintf(stderr, "Plugin %d killed by signal %d\n",
613
proc->pid, WTERMSIG(proc->status));
863
fprintf(stderr, "Plugin %u killed by signal %d\n",
864
(unsigned int) (proc->pid),
865
WTERMSIG(proc->status));
614
866
} else if(WCOREDUMP(proc->status)){
615
fprintf(stderr, "Plugin %d dumped core\n", proc->pid);
867
fprintf(stderr, "Plugin %d dumped core\n",
868
(unsigned int) (proc->pid));
618
871
/* Remove the plugin */
619
872
FD_CLR(proc->fd, &rfds_all);
620
873
/* Block signal while modifying process_list */
621
ret = sigprocmask (SIG_BLOCK, &sigchld_action.sa_mask, NULL);
874
ret = sigprocmask(SIG_BLOCK, &sigchld_action.sa_mask, NULL);
623
876
perror("sigprocmask");
624
877
exitstatus = EXIT_FAILURE;
627
880
/* Delete this process entry from the list */
628
881
if(process_list == proc){
653
906
/* This process exited nicely, so print its buffer */
654
for(size_t written = 0; written < proc->buffer_length;
655
written += (size_t)ret){
656
ret = TEMP_FAILURE_RETRY(write(STDOUT_FILENO,
657
proc->buffer + written,
662
exitstatus = EXIT_FAILURE;
908
bool bret = print_out_password(proc->buffer,
909
proc->buffer_length);
911
perror("print_out_password");
912
exitstatus = EXIT_FAILURE;
668
916
/* This process has not completed. Does it have any output? */
669
917
if(proc->eof or not FD_ISSET(proc->fd, &rfds)){
699
if(process_list == NULL){
700
fprintf(stderr, "All plugin processes failed, exiting\n");
701
exitstatus = EXIT_FAILURE;
951
if(process_list == NULL or exitstatus != EXIT_SUCCESS){
952
/* Fallback if all plugins failed, none are found or an error
955
fprintf(stderr, "Going to fallback mode using getpass(3)\n");
956
char *passwordbuffer = getpass("Password: ");
957
bret = print_out_password(passwordbuffer, strlen(passwordbuffer));
959
perror("print_out_password");
960
exitstatus = EXIT_FAILURE;
705
964
/* Restore old signal handler */
706
sigaction(SIGCHLD, &old_sigchld_action, NULL);
710
/* Free the plugin list */
711
for(plugin *next; plugin_list != NULL; plugin_list = next){
712
next = plugin_list->next;
713
free(plugin_list->argv);
965
ret = sigaction(SIGCHLD, &old_sigchld_action, NULL);
968
exitstatus = EXIT_FAILURE;
971
if(custom_argv != NULL){
972
for(char **arg = custom_argv+1; *arg != NULL; arg++){
977
free_plugin_list(plugin_list);