27
28
#include <stdlib.h> /* malloc(), exit(), EXIT_FAILURE,
28
29
EXIT_SUCCESS, realloc() */
29
30
#include <stdbool.h> /* bool, true, false */
30
#include <stdio.h> /* perror, popen(), fileno(),
31
fprintf(), stderr, STDOUT_FILENO */
31
#include <stdio.h> /* perror, fileno(), fprintf(),
32
stderr, STDOUT_FILENO */
32
33
#include <sys/types.h> /* DIR, opendir(), stat(), struct
33
34
stat, waitpid(), WIFEXITED(),
34
35
WEXITSTATUS(), wait(), pid_t,
46
47
fcntl(), setuid(), setgid(),
47
48
F_GETFD, F_SETFD, FD_CLOEXEC,
48
49
access(), pipe(), fork(), close()
49
dup2, STDOUT_FILENO, _exit(),
50
dup2(), STDOUT_FILENO, _exit(),
50
51
execv(), write(), read(),
52
53
#include <fcntl.h> /* fcntl(), F_GETFD, F_SETFD,
69
70
#define PDIR "/lib/mandos/plugins.d"
70
71
#define AFILE "/conf/conf.d/mandos/plugin-runner.conf"
72
const char *argp_program_version = "plugin-runner 1.0";
73
const char *argp_program_version = "plugin-runner " VERSION;
73
74
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
76
typedef struct plugin{
77
char *name; /* can be NULL or any plugin name */
77
typedef struct process{
84
/* Variables used for running processes*/
84
91
volatile bool completed;
85
92
volatile int status;
89
typedef struct plugin{
90
char *name; /* can be NULL or any plugin name */
96
93
struct plugin *next;
99
static plugin *getplugin(char *name, plugin **plugin_list){
100
for (plugin *p = *plugin_list; p != NULL; p = p->next){
101
if ((p->name == name)
102
or (p->name and name and (strcmp(p->name, name) == 0))){
96
static plugin *plugin_list = NULL;
98
/* Gets an existing plugin based on name,
99
or if none is found, creates a new one */
100
static plugin *getplugin(char *name){
101
/* Check for exiting plugin with that name */
102
for(plugin *p = plugin_list; p != NULL; p = p->next){
104
or (p->name and name and (strcmp(p->name, name) == 0))){
106
108
/* Create a new plugin */
107
109
plugin *new_plugin = malloc(sizeof(plugin));
108
if (new_plugin == NULL){
110
if(new_plugin == NULL){
111
113
char *copy_name = NULL;
119
121
*new_plugin = (plugin) { .name = copy_name,
122
123
.disabled = false,
123
.next = *plugin_list };
124
.next = plugin_list };
125
126
new_plugin->argv = malloc(sizeof(char *) * 2);
126
if (new_plugin->argv == NULL){
127
if(new_plugin->argv == NULL){
128
129
free(new_plugin);
131
132
new_plugin->argv[0] = copy_name;
132
133
new_plugin->argv[1] = NULL;
134
135
new_plugin->environ = malloc(sizeof(char *));
135
136
if(new_plugin->environ == NULL){
178
180
/* Add to a plugin's environment */
179
static bool add_environment(plugin *p, const char *def){
181
static bool add_environment(plugin *p, const char *def, bool replace){
185
/* namelen = length of name of environment variable */
186
size_t namelen = (size_t)(strchrnul(def, '=') - def);
187
/* Search for this environment variable */
188
for(char **e = p->environ; *e != NULL; e++){
189
if(strncmp(*e, def, namelen + 1) == 0){
190
/* It already exists */
192
char *new = realloc(*e, strlen(def) + 1);
183
202
return add_to_char_array(def, &(p->environ), &(p->envc));
188
206
* Based on the example in the GNU LibC manual chapter 13.13 "File
189
207
* Descriptor Flags".
190
208
* *Note File Descriptor Flags:(libc)Descriptor Flags.
192
static int set_cloexec_flag(int fd)
210
static int set_cloexec_flag(int fd){
194
211
int ret = fcntl(fd, F_GETFD, 0);
195
212
/* If reading the flags failed, return error indication now. */
200
217
return fcntl(fd, F_SETFD, ret | FD_CLOEXEC);
203
process *process_list = NULL;
205
221
/* Mark processes as completed when they exit, and save their exit
207
void handle_sigchld(__attribute__((unused)) int sig){
223
static void handle_sigchld(__attribute__((unused)) int sig){
209
process *proc = process_list;
225
plugin *proc = plugin_list;
211
227
pid_t pid = waitpid(-1, &status, WNOHANG);
237
bool print_out_password(const char *buffer, size_t length){
253
/* Prints out a password to stdout */
254
static bool print_out_password(const char *buffer, size_t length){
239
if(length>0 and buffer[length-1] == '\n'){
242
256
for(size_t written = 0; written < length; written += (size_t)ret){
243
257
ret = TEMP_FAILURE_RETRY(write(STDOUT_FILENO, buffer + written,
244
258
length - 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);
266
/* Removes and free a plugin from the plugin list */
267
static void free_plugin(plugin *plugin_node){
269
for(char **arg = plugin_node->argv; *arg != NULL; arg++){
272
free(plugin_node->argv);
273
for(char **env = plugin_node->environ; *env != NULL; env++){
276
free(plugin_node->environ);
277
free(plugin_node->buffer);
279
/* Removes the plugin from the singly-linked list */
280
if(plugin_node == plugin_list){
281
/* First one - simple */
282
plugin_list = plugin_list->next;
284
/* Second one or later */
285
for(plugin *p = plugin_list; p != NULL; p = p->next){
286
if(p->next == plugin_node){
287
p->next = plugin_node->next;
296
static void free_plugin_list(void){
297
while(plugin_list != NULL){
298
free_plugin(plugin_list);
304
340
{ .name = "global-options", .key = 'g',
305
341
.arg = "OPTION[,OPTION[,...]]",
306
342
.doc = "Options passed to all plugins" },
307
{ .name = "global-envs", .key = 'e',
343
{ .name = "global-env", .key = 'G',
308
344
.arg = "VAR=value",
309
345
.doc = "Environment variable passed to all plugins" },
310
346
{ .name = "options-for", .key = 'o',
311
347
.arg = "PLUGIN:OPTION[,OPTION[,...]]",
312
348
.doc = "Options passed only to specified plugin" },
313
{ .name = "envs-for", .key = 'f',
349
{ .name = "env-for", .key = 'E',
314
350
.arg = "PLUGIN:ENV=value",
315
351
.doc = "Environment variable passed to specified plugin" },
316
352
{ .name = "disable", .key = 'd',
318
354
.doc = "Disable a specific plugin", .group = 1 },
355
{ .name = "enable", .key = 'e',
357
.doc = "Enable a specific plugin", .group = 1 },
319
358
{ .name = "plugin-dir", .key = 128,
320
359
.arg = "DIRECTORY",
321
360
.doc = "Specify a different plugin directory", .group = 2 },
336
error_t parse_opt (int key, char *arg, struct argp_state *state) {
337
/* Get the INPUT argument from `argp_parse', which we know is a
338
pointer to our plugin list pointer. */
339
plugin **plugins = state->input;
375
error_t parse_opt(int key, char *arg, __attribute__((unused))
376
struct argp_state *state) {
378
case 'g': /* --global-options */
344
381
while((p = strsep(&arg, ",")) != NULL){
345
382
if(p[0] == '\0'){
348
if(not add_argument(getplugin(NULL, plugins), p)){
385
if(not add_argument(getplugin(NULL), p)){
349
386
perror("add_argument");
350
387
return ARGP_ERR_UNKNOWN;
392
case 'G': /* --global-env */
360
char *envdef = strdup(arg);
364
if(not add_environment(getplugin(NULL, plugins), envdef)){
365
perror("add_environment");
396
if(not add_environment(getplugin(NULL), arg, true)){
397
perror("add_environment");
400
case 'o': /* --options-for */
371
402
char *p_name = strsep(&arg, ":");
372
if(p_name[0] == '\0'){
403
if(p_name[0] == '\0' or arg == NULL){
375
406
char *opt = strsep(&arg, ":");
407
if(opt[0] == '\0' or opt == NULL){
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;
411
while((p = strsep(&opt, ",")) != NULL){
415
if(not add_argument(getplugin(p_name), p)){
416
perror("add_argument");
417
return ARGP_ERR_UNKNOWN;
422
case 'E': /* --env-for */
399
428
if(envdef == NULL){
402
char *p_name = strndup(arg, (size_t) (envdef-arg));
407
if(not add_environment(getplugin(p_name, plugins), envdef)){
432
if(not add_environment(getplugin(arg), envdef+1, true)){
408
433
perror("add_environment");
414
plugin *p = getplugin(arg, plugins);
437
case 'd': /* --disable */
439
plugin *p = getplugin(arg);
416
441
return ARGP_ERR_UNKNOWN;
418
443
p->disabled = true;
446
case 'e': /* --enable */
448
plugin *p = getplugin(arg);
450
return ARGP_ERR_UNKNOWN;
455
case 128: /* --plugin-dir */
422
457
plugindir = strdup(arg);
423
458
if(plugindir == NULL){
424
459
perror("strdup");
462
case 129: /* --config-file */
463
/* This is already done by parse_opt_config_file() */
465
case 130: /* --userid */
466
/* In the GNU C library, uid_t is always unsigned int */
467
ret = sscanf(arg, "%u", &uid);
469
fprintf(stderr, "Bad user ID number: \"%s\", using %u\n", arg,
473
case 131: /* --groupid */
474
/* In the GNU C library, gid_t is always unsigned int */
475
ret = sscanf(arg, "%u", &gid);
477
fprintf(stderr, "Bad group ID number: \"%s\", using %u\n",
481
case 132: /* --debug */
485
* When adding more options before this line, remember to also add a
486
* "case" to the "parse_opt_config_file" function below.
489
/* Cryptsetup always passes an argument, which is an empty
490
string if "none" was specified in /etc/crypttab. So if
491
argument was empty, we ignore it silently. */
493
fprintf(stderr, "Ignoring unknown argument \"%s\"\n", arg);
499
return ARGP_ERR_UNKNOWN;
504
/* This option parser is the same as parse_opt() above, except it
505
ignores everything but the --config-file option. */
506
error_t parse_opt_config_file(int key, char *arg,
507
__attribute__((unused))
508
struct argp_state *state) {
510
case 'g': /* --global-options */
511
case 'G': /* --global-env */
512
case 'o': /* --options-for */
513
case 'E': /* --env-for */
514
case 'd': /* --disable */
515
case 'e': /* --enable */
516
case 128: /* --plugin-dir */
518
case 129: /* --config-file */
428
520
argfile = strdup(arg);
429
521
if(argfile == NULL){
430
522
perror("strdup");
434
uid = (uid_t)strtol(arg, NULL, 10);
437
gid = (gid_t)strtol(arg, NULL, 10);
525
case 130: /* --userid */
526
case 131: /* --groupid */
527
case 132: /* --debug */
442
528
case ARGP_KEY_ARG:
443
fprintf(stderr, "Ignoring unknown argument \"%s\"\n", arg);
445
529
case ARGP_KEY_END:
453
plugin *plugin_list = NULL;
455
struct argp argp = { .options = options, .parser = parse_opt,
456
.args_doc = "[+PLUS_SEPARATED_OPTIONS]",
537
struct argp argp = { .options = options,
538
.parser = parse_opt_config_file,
457
540
.doc = "Mandos plugin runner -- Run plugins" };
459
ret = argp_parse (&argp, argc, argv, 0, 0, &plugin_list);
460
if (ret == ARGP_ERR_UNKNOWN){
542
/* Parse using parse_opt_config_file() in order to get the custom
543
config file location, if any. */
544
ret = argp_parse(&argp, argc, argv, ARGP_IN_ORDER, 0, NULL);
545
if(ret == ARGP_ERR_UNKNOWN){
461
546
fprintf(stderr, "Unknown error while parsing arguments\n");
462
547
exitstatus = EXIT_FAILURE;
466
if (argfile == NULL){
551
/* Reset to the normal argument parser */
552
argp.parser = parse_opt;
554
/* Open the configfile if available */
467
556
conffp = fopen(AFILE, "r");
469
558
conffp = fopen(argfile, "r");
472
560
if(conffp != NULL){
473
561
char *org_line = NULL;
474
562
char *p, *arg, *new_arg, *line;
477
564
const char whitespace_delims[] = " \r\t\f\v\n";
478
565
const char comment_delim[] = "#";
525
614
/* Check for harmful errors and go to fallback. Other errors might
526
615
not affect opening plugins */
527
if (errno == EMFILE or errno == ENFILE or errno == ENOMEM){
616
if(errno == EMFILE or errno == ENFILE or errno == ENOMEM){
529
618
exitstatus = EXIT_FAILURE;
622
/* If there was any arguments from configuration file,
623
pass them to parser as command arguments */
534
624
if(custom_argv != NULL){
535
ret = argp_parse (&argp, custom_argc, custom_argv, 0, 0, &plugin_list);
536
if (ret == ARGP_ERR_UNKNOWN){
625
ret = argp_parse(&argp, custom_argc, custom_argv, ARGP_IN_ORDER,
627
if(ret == ARGP_ERR_UNKNOWN){
537
628
fprintf(stderr, "Unknown error while parsing arguments\n");
538
629
exitstatus = EXIT_FAILURE;
634
/* Parse actual command line arguments, to let them override the
636
ret = argp_parse(&argp, argc, argv, ARGP_IN_ORDER, 0, NULL);
637
if(ret == ARGP_ERR_UNKNOWN){
638
fprintf(stderr, "Unknown error while parsing arguments\n");
639
exitstatus = EXIT_FAILURE;
544
644
for(plugin *p = plugin_list; p != NULL; p=p->next){
545
645
fprintf(stderr, "Plugin: %s has %d arguments\n",
655
ret = asprintf(&filename, "%s/%s", plugindir, dirst->d_name);
755
if(plugindir == NULL){
756
ret = asprintf(&filename, PDIR "/%s", dirst->d_name);
758
ret = asprintf(&filename, "%s/%s", plugindir, dirst->d_name);
657
761
perror("asprintf");
661
765
ret = stat(filename, &st);
668
if (not S_ISREG(st.st_mode) or (access(filename, X_OK) != 0)){
772
/* Ignore non-executable files */
773
if(not S_ISREG(st.st_mode) or (access(filename, X_OK) != 0)){
670
775
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
671
776
" with bad type or mode\n", filename);
742
844
/* Block SIGCHLD until process is safely in process list */
743
ret = sigprocmask (SIG_BLOCK, &sigchld_action.sa_mask, NULL);
845
ret = sigprocmask(SIG_BLOCK, &sigchld_action.sa_mask, NULL);
745
847
perror("sigprocmask");
746
848
exitstatus = EXIT_FAILURE;
749
// Starting a new process to be watched
851
/* Starting a new process to be watched */
750
852
pid_t pid = fork();
896
close(pipefd[1]); /* Close unused write end of pipe */
795
close(pipefd[1]); /* close unused write end of pipe */
796
process *new_process = malloc(sizeof(process));
797
if (new_process == NULL){
799
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
898
plugin *new_plugin = getplugin(dirst->d_name);
899
if(new_plugin == NULL){
901
ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
801
perror("sigprocmask");
903
perror("sigprocmask");
803
905
exitstatus = EXIT_FAILURE;
807
*new_process = (struct process){ .pid = pid,
809
.next = process_list };
811
process_list = new_process;
909
new_plugin->pid = pid;
910
new_plugin->fd = pipefd[0];
812
912
/* Unblock SIGCHLD so signal handler can be run if this process
813
913
has already completed */
814
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
914
ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
816
916
perror("sigprocmask");
817
917
exitstatus = EXIT_FAILURE;
821
FD_SET(new_process->fd, &rfds_all);
921
FD_SET(new_plugin->fd, &rfds_all);
823
if (maxfd < new_process->fd){
824
maxfd = new_process->fd;
923
if(maxfd < new_plugin->fd){
924
maxfd = new_plugin->fd;
829
free_plugin_list(plugin_list);
835
if (process_list == NULL){
836
fprintf(stderr, "No plugin processes started. Incorrect plugin"
931
for(plugin *p = plugin_list; p != NULL; p = p->next){
936
fprintf(stderr, "No plugin processes started. Incorrect plugin"
942
/* Main loop while running plugins exist */
841
944
fd_set rfds = rfds_all;
842
945
int select_ret = select(maxfd+1, &rfds, NULL, NULL, NULL);
843
if (select_ret == -1){
946
if(select_ret == -1){
844
947
perror("select");
845
948
exitstatus = EXIT_FAILURE;
848
951
/* OK, now either a process completed, or something can be read
849
952
from one of them */
850
for(process *proc = process_list; proc ; proc = proc->next){
953
for(plugin *proc = plugin_list; proc != NULL;){
851
954
/* Is this process completely done? */
852
955
if(proc->eof and proc->completed){
853
956
/* Only accept the plugin output if it exited cleanly */
854
957
if(not WIFEXITED(proc->status)
855
958
or WEXITSTATUS(proc->status) != 0){
856
959
/* Bad exit by plugin */
858
962
if(WIFEXITED(proc->status)){
859
963
fprintf(stderr, "Plugin %u exited with status %d\n",
864
968
(unsigned int) (proc->pid),
865
969
WTERMSIG(proc->status));
866
970
} else if(WCOREDUMP(proc->status)){
867
fprintf(stderr, "Plugin %d dumped core\n",
971
fprintf(stderr, "Plugin %u dumped core\n",
868
972
(unsigned int) (proc->pid));
871
976
/* Remove the plugin */
872
977
FD_CLR(proc->fd, &rfds_all);
873
979
/* Block signal while modifying process_list */
874
980
ret = sigprocmask(SIG_BLOCK, &sigchld_action.sa_mask, NULL);
877
983
exitstatus = EXIT_FAILURE;
880
/* Delete this process entry from the list */
881
if(process_list == proc){
882
/* First one - simple */
883
process_list = proc->next;
885
/* Second one or later */
886
for(process *p = process_list; p != NULL; p = p->next){
888
p->next = proc->next;
987
plugin *next_plugin = proc->next;
893
991
/* We are done modifying process list, so unblock signal */
894
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask,
992
ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask,
897
995
perror("sigprocmask");
901
/* We deleted this process from the list, so we can't go
902
proc->next. Therefore, start over from the beginning of
996
exitstatus = EXIT_FAILURE;
1000
if(plugin_list == NULL){
906
1007
/* This process exited nicely, so print its buffer */
908
1009
bool bret = print_out_password(proc->buffer,
909
1010
proc->buffer_length);
916
1018
/* This process has not completed. Does it have any output? */
917
1019
if(proc->eof or not FD_ISSET(proc->fd, &rfds)){
918
1020
/* This process had nothing to say at this time */
921
1024
/* Before reading, make the process' data buffer large enough */
922
1025
if(proc->buffer_length + BUFFER_SIZE > proc->buffer_size){
923
1026
proc->buffer = realloc(proc->buffer, proc->buffer_size
924
1027
+ (size_t) BUFFER_SIZE);
925
if (proc->buffer == NULL){
1028
if(proc->buffer == NULL){
926
1029
perror("malloc");
927
1030
exitstatus = EXIT_FAILURE;
930
1033
proc->buffer_size += BUFFER_SIZE;
932
1035
/* Read from the process */
933
ret = read(proc->fd, proc->buffer + proc->buffer_length,
1036
sret = read(proc->fd, proc->buffer + proc->buffer_length,
936
1039
/* Read error from this process; ignore the error */
941
1045
proc->eof = true;
943
proc->buffer_length += (size_t) ret;
1047
proc->buffer_length += (size_t) sret;
951
if(process_list == NULL or exitstatus != EXIT_SUCCESS){
1055
if(plugin_list == NULL or exitstatus != EXIT_SUCCESS){
952
1056
/* Fallback if all plugins failed, none are found or an error
955
1059
fprintf(stderr, "Going to fallback mode using getpass(3)\n");
956
1060
char *passwordbuffer = getpass("Password: ");
957
bret = print_out_password(passwordbuffer, strlen(passwordbuffer));
1061
size_t len = strlen(passwordbuffer);
1062
/* Strip trailing newline */
1063
if(len > 0 and passwordbuffer[len-1] == '\n'){
1064
passwordbuffer[len-1] = '\0'; /* not strictly necessary */
1067
bret = print_out_password(passwordbuffer, len);
959
1069
perror("print_out_password");
960
1070
exitstatus = EXIT_FAILURE;
967
1077
perror("sigaction");
968
1078
exitstatus = EXIT_FAILURE;
971
1081
if(custom_argv != NULL){
972
1082
for(char **arg = custom_argv+1; *arg != NULL; arg++){
975
1085
free(custom_argv);
977
free_plugin_list(plugin_list);
979
1088
if(dir != NULL){
983
/* Free the process list and kill the processes */
984
for(process *next; process_list != NULL; process_list = next){
985
next = process_list->next;
986
close(process_list->fd);
987
ret = kill(process_list->pid, SIGTERM);
988
if(ret == -1 and errno != ESRCH){
989
/* set-uid proccesses migth not get closed */
1092
/* Kill the processes */
1093
for(plugin *p = plugin_list; p != NULL; p = p->next){
1096
ret = kill(p->pid, SIGTERM);
1097
if(ret == -1 and errno != ESRCH){
1098
/* Set-uid proccesses might not get closed */
992
free(process_list->buffer);
996
1104
/* Wait for any remaining child processes to terminate */