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, error_t */
60
#include <signal.h> /* struct sigaction, sigemptyset(),
61
sigaddset(), sigaction(),
62
sigprocmask(), SIG_BLOCK, SIGCHLD,
63
SIG_UNBLOCK, kill() */
64
#include <errno.h> /* errno, EBADF */
66
#define BUFFER_SIZE 256
67
#define ARGFILE "/conf/conf.d/mandos/plugin-runner.conf"
69
const char *argp_program_version = "plugin-runner 1.0";
70
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
49
#include <argp.h> /* struct argp_option,
50
struct argp_state, struct argp,
103
79
/* Create a new plugin */
104
80
plugin *new_plugin = malloc(sizeof(plugin));
105
81
if (new_plugin == NULL){
108
char *copy_name = NULL;
110
copy_name = strdup(name);
111
if(copy_name == NULL){
116
*new_plugin = (plugin) { .name = copy_name,
120
.next = *plugin_list };
85
new_plugin->name = name;
122
86
new_plugin->argv = malloc(sizeof(char *) * 2);
123
87
if (new_plugin->argv == NULL){
128
new_plugin->argv[0] = copy_name;
91
new_plugin->argv[0] = name;
129
92
new_plugin->argv[1] = NULL;
131
new_plugin->environ = malloc(sizeof(char *));
132
if(new_plugin->environ == NULL){
134
free(new_plugin->argv);
138
new_plugin->environ[0] = NULL;
94
new_plugin->disabled = false;
95
new_plugin->next = *plugin_list;
139
96
/* Append the new plugin to the list */
140
97
*plugin_list = new_plugin;
141
98
return new_plugin;
144
/* Helper function for add_argument and add_environment */
145
static bool add_to_char_array(const char *new, char ***array,
147
/* Resize the pointed-to array to hold one more pointer */
148
*array = realloc(*array, sizeof(char *)
149
* (size_t) ((*len) + 2));
154
/* Make a copy of the new string */
155
char *copy = strdup(new);
159
/* Insert the copy */
160
(*array)[*len] = copy;
162
/* Add a new terminating NULL pointer to the last element */
163
(*array)[*len] = NULL;
167
/* Add to a plugin's argument vector */
168
static bool add_argument(plugin *p, const char *arg){
172
return add_to_char_array(arg, &(p->argv), &(p->argc));
175
/* Add to a plugin's environment */
176
static bool add_environment(plugin *p, const char *def){
180
return add_to_char_array(def, &(p->environ), &(p->envc));
101
void addargument(plugin *p, char *arg){
102
p->argv[p->argc] = arg;
103
p->argv = realloc(p->argv, sizeof(char *) * (size_t)(p->argc + 2));
104
if (p->argv == NULL){
109
p->argv[p->argc] = NULL;
185
113
* Based on the example in the GNU LibC manual chapter 13.13 "File
186
114
* Descriptor Flags".
187
115
* *Note File Descriptor Flags:(libc)Descriptor Flags.
189
static int set_cloexec_flag(int fd)
117
int set_cloexec_flag(int fd)
191
119
int ret = fcntl(fd, F_GETFD, 0);
192
120
/* If reading the flags failed, return error indication now. */
197
125
return fcntl(fd, F_SETFD, ret | FD_CLOEXEC);
200
process *process_list = NULL;
202
/* Mark a process as completed when it exits, and save its exit
204
void handle_sigchld(__attribute__((unused)) int sig){
205
process *proc = process_list;
207
pid_t pid = wait(&status);
212
while(proc != NULL and proc->pid != pid){
216
/* Process not found in process list */
219
proc->status = status;
220
proc->completed = true;
223
bool print_out_password(const char *buffer, size_t length){
225
if(length>0 and buffer[length-1] == '\n'){
228
for(size_t written = 0; written < length; written += (size_t)ret){
229
ret = TEMP_FAILURE_RETRY(write(STDOUT_FILENO, buffer + written,
238
char **add_to_argv(char **argv, int *argc, char *arg){
241
argv = malloc(sizeof(char*) * 2);
245
argv[0] = NULL; /* Will be set to argv[0] in main before parsing */
249
argv = realloc(argv, sizeof(char *)
250
* ((unsigned int) *argc + 1));
259
static void free_plugin_list(plugin *plugin_list){
260
for(plugin *next; plugin_list != NULL; plugin_list = next){
261
next = plugin_list->next;
262
for(char **arg = plugin_list->argv; *arg != NULL; arg++){
265
free(plugin_list->argv);
266
for(char **env = plugin_list->environ; *env != NULL; env++){
269
free(plugin_list->environ);
129
#define BUFFER_SIZE 256
131
const char *argp_program_version =
132
"plugbasedclient 0.9";
133
const char *argp_program_bug_address =
134
"<mandos@fukt.bsnet.se>";
274
136
int main(int argc, char *argv[]){
275
const char *plugindir = "/lib/mandos/plugins.d";
276
const char *argfile = ARGFILE;
137
const char *plugindir = "/conf/conf.d/mandos/plugins.d";
278
138
size_t d_name_len;
280
140
struct dirent *dirst;
283
143
int ret, maxfd = 0;
144
process *process_list = NULL;
286
145
bool debug = false;
287
146
int exitstatus = EXIT_SUCCESS;
288
struct sigaction old_sigchld_action;
289
struct sigaction sigchld_action = { .sa_handler = handle_sigchld,
290
.sa_flags = SA_NOCLDSTOP };
291
char **custom_argv = NULL;
294
/* Establish a signal handler */
295
sigemptyset(&sigchld_action.sa_mask);
296
ret = sigaddset(&sigchld_action.sa_mask, SIGCHLD);
299
exitstatus = EXIT_FAILURE;
302
ret = sigaction(SIGCHLD, &sigchld_action, &old_sigchld_action);
305
exitstatus = EXIT_FAILURE;
309
148
/* The options we understand. */
310
149
struct argp_option options[] = {
311
150
{ .name = "global-options", .key = 'g',
312
151
.arg = "OPTION[,OPTION[,...]]",
313
152
.doc = "Options passed to all plugins" },
314
{ .name = "global-envs", .key = 'e',
316
.doc = "Environment variable passed to all plugins" },
317
153
{ .name = "options-for", .key = 'o',
318
154
.arg = "PLUGIN:OPTION[,OPTION[,...]]",
319
155
.doc = "Options passed only to specified plugin" },
320
{ .name = "envs-for", .key = 'f',
321
.arg = "PLUGIN:ENV=value",
322
.doc = "Environment variable passed to specified plugin" },
323
156
{ .name = "disable", .key = 'd',
325
158
.doc = "Disable a specific plugin", .group = 1 },
326
159
{ .name = "plugin-dir", .key = 128,
327
160
.arg = "DIRECTORY",
328
161
.doc = "Specify a different plugin directory", .group = 2 },
329
{ .name = "userid", .key = 129,
330
.arg = "ID", .flags = 0,
331
.doc = "User ID the plugins will run as", .group = 2 },
332
{ .name = "groupid", .key = 130,
333
.arg = "ID", .flags = 0,
334
.doc = "Group ID the plugins will run as", .group = 2 },
335
{ .name = "debug", .key = 131,
162
{ .name = "debug", .key = 129,
336
163
.doc = "Debug mode", .group = 3 },
340
167
error_t parse_opt (int key, char *arg, struct argp_state *state) {
341
/* Get the INPUT argument from `argp_parse', which we know is a
342
pointer to our plugin list pointer. */
168
/* Get the INPUT argument from `argp_parse', which we
169
know is a pointer to our plugin list pointer. */
343
170
plugin **plugins = state->input;
346
173
if (arg != NULL){
348
while((p = strsep(&arg, ",")) != NULL){
352
if(not add_argument(getplugin(NULL, plugins), p)){
353
perror("add_argument");
354
return ARGP_ERR_UNKNOWN;
364
char *envdef = strdup(arg);
368
if(not add_environment(getplugin(NULL, plugins), envdef)){
369
perror("add_environment");
174
char *p = strtok(arg, ",");
176
addargument(getplugin(NULL, plugins), p);
177
p = strtok(NULL, ",");
374
182
if (arg != NULL){
375
char *p_name = strsep(&arg, ":");
376
if(p_name[0] == '\0'){
379
char *opt = strsep(&arg, ":");
385
while((p = strsep(&opt, ",")) != NULL){
389
if(not add_argument(getplugin(p_name, plugins), p)){
390
perror("add_argument");
391
return ARGP_ERR_UNKNOWN;
402
char *envdef = strchr(arg, ':');
406
char *p_name = strndup(arg, (size_t) (envdef-arg));
411
if(not add_environment(getplugin(p_name, plugins), envdef)){
412
perror("add_environment");
183
char *name = strtok(arg, ":");
184
char *p = strtok(NULL, ":");
188
addargument(getplugin(name, plugins), p);
189
p = strtok(NULL, ",");
417
195
if (arg != NULL){
418
plugin *p = getplugin(arg, plugins);
420
return ARGP_ERR_UNKNOWN;
196
getplugin(arg, plugins)->disabled = true;
429
uid = (uid_t)strtol(arg, NULL, 10);
432
gid = (gid_t)strtol(arg, NULL, 10);
437
205
case ARGP_KEY_ARG:
438
fprintf(stderr, "Ignoring unknown argument \"%s\"\n", arg);
440
208
case ARGP_KEY_END:
448
216
plugin *plugin_list = NULL;
450
218
struct argp argp = { .options = options, .parser = parse_opt,
451
.args_doc = "[+PLUS_SEPARATED_OPTIONS]",
452
220
.doc = "Mandos plugin runner -- Run plugins" };
454
ret = argp_parse (&argp, argc, argv, 0, 0, &plugin_list);
455
if (ret == ARGP_ERR_UNKNOWN){
456
fprintf(stderr, "Unknown error while parsing arguments\n");
457
exitstatus = EXIT_FAILURE;
461
conffp = fopen(argfile, "r");
463
char *org_line = NULL;
464
char *p, *arg, *new_arg, *line;
467
const char whitespace_delims[] = " \r\t\f\v\n";
468
const char comment_delim[] = "#";
471
sret = getline(&org_line, &size, conffp);
477
arg = strsep(&line, comment_delim);
478
while((p = strsep(&arg, whitespace_delims)) != NULL){
483
custom_argv = add_to_argv(custom_argv, &custom_argc, new_arg);
484
if (custom_argv == NULL){
485
perror("add_to_argv");
486
exitstatus = EXIT_FAILURE;
493
/* Check for harmful errors and go to fallback. Other errors might
494
not affect opening plugins */
495
if (errno == EMFILE or errno == ENFILE or errno == ENOMEM){
497
exitstatus = EXIT_FAILURE;
502
if(custom_argv != NULL){
503
custom_argv[0] = argv[0];
504
ret = argp_parse (&argp, custom_argc, custom_argv, 0, 0, &plugin_list);
505
if (ret == ARGP_ERR_UNKNOWN){
506
fprintf(stderr, "Unknown error while parsing arguments\n");
507
exitstatus = EXIT_FAILURE;
222
argp_parse (&argp, argc, argv, 0, 0, &plugin_list);
513
225
for(plugin *p = plugin_list; p != NULL; p=p->next){
619
ret = asprintf(&filename, "%s/%s", plugindir, dirst->d_name);
625
ret = stat(filename, &st);
315
char *filename = malloc(d_name_len + strlen(plugindir) + 2);
316
if (filename == NULL){
318
exitstatus = EXIT_FAILURE;
321
strcpy(filename, plugindir);
322
strcat(filename, "/");
323
strcat(filename, dirst->d_name);
632
327
if (not S_ISREG(st.st_mode) or (access(filename, X_OK) != 0)){
634
329
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
635
330
" with bad type or mode\n", filename);
640
plugin *p = getplugin(dirst->d_name, &plugin_list);
334
if(getplugin(dirst->d_name, &plugin_list)->disabled){
648
336
fprintf(stderr, "Ignoring disabled plugin \"%s\"\n",
341
plugin *p = getplugin(dirst->d_name, &plugin_list);
655
343
/* Add global arguments to argument list for this plugin */
656
344
plugin *g = getplugin(NULL, &plugin_list);
658
for(char **a = g->argv + 1; *a != NULL; a++){
659
if(not add_argument(p, *a)){
660
perror("add_argument");
663
/* Add global environment variables */
664
for(char **e = g->environ; *e != NULL; e++){
665
if(not add_environment(p, *e)){
666
perror("add_environment");
671
/* If this plugin has any environment variables, we will call
672
using execve and need to duplicate the environment from this
674
if(p->environ[0] != NULL){
675
for(char **e = environ; *e != NULL; e++){
676
char *copy = strdup(*e);
681
if(not add_environment(p, copy)){
682
perror("add_environment");
345
for(char **a = g->argv + 1; *a != NULL; a++){
688
350
ret = pipe(pipefd);
691
353
exitstatus = EXIT_FAILURE;
694
356
ret = set_cloexec_flag(pipefd[0]);
696
358
perror("set_cloexec_flag");
697
359
exitstatus = EXIT_FAILURE;
700
362
ret = set_cloexec_flag(pipefd[1]);
702
364
perror("set_cloexec_flag");
703
365
exitstatus = EXIT_FAILURE;
706
/* Block SIGCHLD until process is safely in process list */
707
ret = sigprocmask (SIG_BLOCK, &sigchld_action.sa_mask, NULL);
709
perror("sigprocmask");
710
exitstatus = EXIT_FAILURE;
713
368
// Starting a new process to be watched
714
369
pid_t pid = fork();
717
exitstatus = EXIT_FAILURE;
721
371
/* this is the child process */
722
ret = sigaction(SIGCHLD, &old_sigchld_action, NULL);
727
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
729
perror("sigprocmask");
733
ret = dup2(pipefd[1], STDOUT_FILENO); /* replace our stdout */
372
dup2(pipefd[1], STDOUT_FILENO); /* replace our stdout */
739
374
if(dirfd(dir) < 0){
740
375
/* If dir has no file descriptor, we could not set FD_CLOEXEC
741
above and must now close it manually here. */
376
and must close it manually */
744
if(p->environ[0] == NULL){
745
if(execv(filename, p->argv) < 0){
750
if(execve(filename, p->argv, p->environ) < 0){
379
if(execv(filename, p->argv) < 0){
757
385
/* parent process */
759
386
close(pipefd[1]); /* close unused write end of pipe */
760
387
process *new_process = malloc(sizeof(process));
761
388
if (new_process == NULL){
762
389
perror("malloc");
763
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
765
perror("sigprocmask");
767
390
exitstatus = EXIT_FAILURE;
771
394
*new_process = (struct process){ .pid = pid,
773
396
.next = process_list };
775
process_list = new_process;
776
/* Unblock SIGCHLD so signal handler can be run if this process
777
has already completed */
778
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
780
perror("sigprocmask");
781
exitstatus = EXIT_FAILURE;
785
397
FD_SET(new_process->fd, &rfds_all);
787
399
if (maxfd < new_process->fd){
788
400
maxfd = new_process->fd;
404
process_list = new_process;
793
free_plugin_list(plugin_list);
407
/* Free the plugin list */
408
for(plugin *next; plugin_list != NULL; plugin_list = next){
409
next = plugin_list->next;
410
free(plugin_list->argv);
799
416
if (process_list == NULL){
800
fprintf(stderr, "No plugin processes started. Incorrect plugin"
417
fprintf(stderr, "No plugin processes started, exiting\n");
805
421
fd_set rfds = rfds_all;
806
422
int select_ret = select(maxfd+1, &rfds, NULL, NULL, NULL);
807
423
if (select_ret == -1){
808
424
perror("select");
809
425
exitstatus = EXIT_FAILURE;
812
/* OK, now either a process completed, or something can be read
814
428
for(process *proc = process_list; proc ; proc = proc->next){
815
/* Is this process completely done? */
816
if(proc->eof and proc->completed){
817
/* Only accept the plugin output if it exited cleanly */
818
if(not WIFEXITED(proc->status)
819
or WEXITSTATUS(proc->status) != 0){
820
/* Bad exit by plugin */
822
if(WIFEXITED(proc->status)){
823
fprintf(stderr, "Plugin %u exited with status %d\n",
824
(unsigned int) (proc->pid),
825
WEXITSTATUS(proc->status));
826
} else if(WIFSIGNALED(proc->status)) {
827
fprintf(stderr, "Plugin %u killed by signal %d\n",
828
(unsigned int) (proc->pid),
829
WTERMSIG(proc->status));
830
} else if(WCOREDUMP(proc->status)){
831
fprintf(stderr, "Plugin %d dumped core\n",
832
(unsigned int) (proc->pid));
835
/* Remove the plugin */
836
FD_CLR(proc->fd, &rfds_all);
837
/* Block signal while modifying process_list */
838
ret = sigprocmask (SIG_BLOCK, &sigchld_action.sa_mask, NULL);
840
perror("sigprocmask");
841
exitstatus = EXIT_FAILURE;
844
/* Delete this process entry from the list */
845
if(process_list == proc){
846
/* First one - simple */
847
process_list = proc->next;
849
/* Second one or later */
850
for(process *p = process_list; p != NULL; p = p->next){
852
p->next = proc->next;
857
/* We are done modifying process list, so unblock signal */
858
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask,
861
perror("sigprocmask");
865
/* We deleted this process from the list, so we can't go
866
proc->next. Therefore, start over from the beginning of
870
/* This process exited nicely, so print its buffer */
872
bool bret = print_out_password(proc->buffer, proc->buffer_length);
874
perror("print_out_password");
875
exitstatus = EXIT_FAILURE;
879
/* This process has not completed. Does it have any output? */
880
if(proc->eof or not FD_ISSET(proc->fd, &rfds)){
881
/* This process had nothing to say at this time */
429
if(not FD_ISSET(proc->fd, &rfds)){
884
/* Before reading, make the process' data buffer large enough */
885
432
if(proc->buffer_length + BUFFER_SIZE > proc->buffer_size){
886
433
proc->buffer = realloc(proc->buffer, proc->buffer_size
887
434
+ (size_t) BUFFER_SIZE);
888
435
if (proc->buffer == NULL){
889
436
perror("malloc");
890
437
exitstatus = EXIT_FAILURE;
893
440
proc->buffer_size += BUFFER_SIZE;
895
/* Read from the process */
896
442
ret = read(proc->fd, proc->buffer + proc->buffer_length,
899
/* Read error from this process; ignore the error */
445
/* Read error from this process; ignore it */
448
proc->buffer_length += (size_t) ret;
906
proc->buffer_length += (size_t) ret;
451
/* wait for process exit */
453
waitpid(proc->pid, &status, 0);
454
if(not WIFEXITED(status) or WEXITSTATUS(status) != 0){
455
FD_CLR(proc->fd, &rfds_all);
458
for(size_t written = 0;
459
written < proc->buffer_length; written += (size_t)ret){
460
ret = TEMP_FAILURE_RETRY(write(STDOUT_FILENO,
461
proc->buffer + written,
466
exitstatus = EXIT_FAILURE;
914
if(process_list == NULL or exitstatus != EXIT_SUCCESS){
915
/* Fallback if all plugins failed, none are found or an error occured */
917
fprintf(stderr, "Going to fallback mode using getpass(3)\n");
918
char *passwordbuffer = getpass("Password: ");
919
bret = print_out_password(passwordbuffer, strlen(passwordbuffer));
921
perror("print_out_password");
922
exitstatus = EXIT_FAILURE;
926
/* Restore old signal handler */
927
ret = sigaction(SIGCHLD, &old_sigchld_action, NULL);
930
exitstatus = EXIT_FAILURE;
933
if(custom_argv != NULL){
934
for(char **arg = custom_argv; *arg != NULL; arg++){
939
free_plugin_list(plugin_list);
945
/* Free the process list and kill the processes */
946
476
for(process *next; process_list != NULL; process_list = next){
947
next = process_list->next;
948
477
close(process_list->fd);
949
ret = kill(process_list->pid, SIGTERM);
950
if(ret == -1 and errno != ESRCH){
951
/* set-uid proccesses migth not get closed */
478
kill(process_list->pid, SIGTERM);
954
479
free(process_list->buffer);
955
480
free(process_list);
958
/* Wait for any remaining child processes to terminate */
966
493
return exitstatus;