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, 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>";
46
#include <argp.h> /* struct argp_option,
47
struct argp_state, struct argp,
103
76
/* Create a new plugin */
104
77
plugin *new_plugin = malloc(sizeof(plugin));
105
78
if (new_plugin == NULL){
108
char *copy_name = strdup(name);
109
if(copy_name == NULL){
113
*new_plugin = (plugin) { .name = copy_name,
117
.next = *plugin_list };
82
new_plugin->name = name;
119
83
new_plugin->argv = malloc(sizeof(char *) * 2);
120
84
if (new_plugin->argv == NULL){
124
new_plugin->argv[0] = copy_name;
88
new_plugin->argv[0] = name;
125
89
new_plugin->argv[1] = NULL;
127
new_plugin->environ = malloc(sizeof(char *));
128
if(new_plugin->environ == NULL){
129
free(new_plugin->argv);
133
new_plugin->environ[0] = NULL;
91
new_plugin->disabled = false;
92
new_plugin->next = *plugin_list;
134
93
/* Append the new plugin to the list */
135
94
*plugin_list = new_plugin;
136
95
return new_plugin;
139
/* Helper function for add_argument and add_environment */
140
static bool add_to_char_array(const char *new, char ***array,
142
/* Resize the pointed-to array to hold one more pointer */
143
*array = realloc(*array, sizeof(char *)
144
* (size_t) ((*len) + 2));
149
/* Make a copy of the new string */
150
char *copy = strdup(new);
154
/* Insert the copy */
155
(*array)[*len] = copy;
157
/* Add a new terminating NULL pointer to the last element */
158
(*array)[*len] = NULL;
162
/* Add to a plugin's argument vector */
163
static bool add_argument(plugin *p, const char *arg){
167
return add_to_char_array(arg, &(p->argv), &(p->argc));
170
/* Add to a plugin's environment */
171
static bool add_environment(plugin *p, const char *def){
175
return add_to_char_array(def, &(p->environ), &(p->envc));
98
void addargument(plugin *p, char *arg){
99
p->argv[p->argc] = arg;
100
p->argv = realloc(p->argv, sizeof(char *) * (size_t)(p->argc + 2));
101
if (p->argv == NULL){
106
p->argv[p->argc] = NULL;
180
110
* Based on the example in the GNU LibC manual chapter 13.13 "File
181
111
* Descriptor Flags".
182
112
* *Note File Descriptor Flags:(libc)Descriptor Flags.
184
static int set_cloexec_flag(int fd)
114
int set_cloexec_flag(int fd)
186
116
int ret = fcntl(fd, F_GETFD, 0);
187
117
/* If reading the flags failed, return error indication now. */
192
122
return fcntl(fd, F_SETFD, ret | FD_CLOEXEC);
195
process *process_list = NULL;
197
/* Mark a process as completed when it exits, and save its exit
199
void handle_sigchld(__attribute__((unused)) int sig){
200
process *proc = process_list;
202
pid_t pid = wait(&status);
207
while(proc != NULL and proc->pid != pid){
211
/* Process not found in process list */
214
proc->status = status;
215
proc->completed = true;
218
bool print_out_password(const char *buffer, size_t length){
220
if(length>0 and buffer[length-1] == '\n'){
223
for(size_t written = 0; written < length; written += (size_t)ret){
224
ret = TEMP_FAILURE_RETRY(write(STDOUT_FILENO, buffer + written,
233
char **add_to_argv(char **argv, int *argc, char *arg){
236
argv = malloc(sizeof(char*) * 2);
240
argv[0] = NULL; /* Will be set to argv[0] in main before parsing */
244
argv = realloc(argv, sizeof(char *)
245
* ((unsigned int) *argc + 1));
254
static void free_plugin_list(plugin *plugin_list){
255
for(plugin *next = plugin_list; plugin_list != NULL; plugin_list = next){
256
next = plugin_list->next;
257
free(plugin_list->name);
258
for(char **arg = plugin_list->argv; *arg != NULL; arg++){
261
free(plugin_list->argv);
262
for(char **env = plugin_list->environ; *env != NULL; env++){
265
free(plugin_list->environ);
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>";
270
133
int main(int argc, char *argv[]){
271
const char *plugindir = "/lib/mandos/plugins.d";
272
const char *argfile = ARGFILE;
134
const char *plugindir = "/conf/conf.d/mandos/plugins.d";
274
135
size_t d_name_len;
276
137
struct dirent *dirst;
279
140
int ret, maxfd = 0;
141
process *process_list = NULL;
282
142
bool debug = false;
283
143
int exitstatus = EXIT_SUCCESS;
284
struct sigaction old_sigchld_action;
285
struct sigaction sigchld_action = { .sa_handler = handle_sigchld,
286
.sa_flags = SA_NOCLDSTOP };
287
char **custom_argv = NULL;
290
/* Establish a signal handler */
291
sigemptyset(&sigchld_action.sa_mask);
292
ret = sigaddset(&sigchld_action.sa_mask, SIGCHLD);
295
exitstatus = EXIT_FAILURE;
298
ret = sigaction(SIGCHLD, &sigchld_action, &old_sigchld_action);
301
exitstatus = EXIT_FAILURE;
305
145
/* The options we understand. */
306
146
struct argp_option options[] = {
307
147
{ .name = "global-options", .key = 'g',
308
148
.arg = "OPTION[,OPTION[,...]]",
309
149
.doc = "Options passed to all plugins" },
310
{ .name = "global-envs", .key = 'e',
312
.doc = "Environment variable passed to all plugins" },
313
150
{ .name = "options-for", .key = 'o',
314
151
.arg = "PLUGIN:OPTION[,OPTION[,...]]",
315
152
.doc = "Options passed only to specified plugin" },
316
{ .name = "envs-for", .key = 'f',
317
.arg = "PLUGIN:ENV=value",
318
.doc = "Environment variable passed to specified plugin" },
319
153
{ .name = "disable", .key = 'd',
321
155
.doc = "Disable a specific plugin", .group = 1 },
322
156
{ .name = "plugin-dir", .key = 128,
323
157
.arg = "DIRECTORY",
324
158
.doc = "Specify a different plugin directory", .group = 2 },
325
{ .name = "userid", .key = 129,
326
.arg = "ID", .flags = 0,
327
.doc = "User ID the plugins will run as", .group = 2 },
328
{ .name = "groupid", .key = 130,
329
.arg = "ID", .flags = 0,
330
.doc = "Group ID the plugins will run as", .group = 2 },
331
{ .name = "debug", .key = 131,
159
{ .name = "debug", .key = 129,
332
160
.doc = "Debug mode", .group = 3 },
336
164
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. */
165
/* Get the INPUT argument from `argp_parse', which we
166
know is a pointer to our plugin list pointer. */
339
167
plugin **plugins = state->input;
342
170
if (arg != 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");
171
char *p = strtok(arg, ",");
173
addargument(getplugin(NULL, plugins), p);
174
p = strtok(NULL, ",");
370
179
if (arg != 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");
180
char *name = strtok(arg, ":");
181
char *p = strtok(NULL, ":");
185
addargument(getplugin(name, plugins), p);
186
p = strtok(NULL, ",");
413
192
if (arg != NULL){
414
plugin *p = getplugin(arg, plugins);
416
return ARGP_ERR_UNKNOWN;
193
getplugin(arg, plugins)->disabled = true;
425
uid = (uid_t)strtol(arg, NULL, 10);
428
gid = (gid_t)strtol(arg, NULL, 10);
433
202
case ARGP_KEY_ARG:
434
fprintf(stderr, "Ignoring unknown argument \"%s\"\n", arg);
436
205
case ARGP_KEY_END:
444
213
plugin *plugin_list = NULL;
446
215
struct argp argp = { .options = options, .parser = parse_opt,
447
.args_doc = "[+PLUS_SEPARATED_OPTIONS]",
448
217
.doc = "Mandos plugin runner -- Run plugins" };
450
ret = argp_parse (&argp, argc, argv, 0, 0, &plugin_list);
451
if (ret == ARGP_ERR_UNKNOWN){
452
fprintf(stderr, "Unknown error while parsing arguments\n");
453
exitstatus = EXIT_FAILURE;
457
conffp = fopen(argfile, "r");
459
char *org_line = NULL;
460
char *p, *arg, *new_arg, *line;
463
const char whitespace_delims[] = " \r\t\f\v\n";
464
const char comment_delim[] = "#";
467
sret = getline(&org_line, &size, conffp);
473
arg = strsep(&line, comment_delim);
474
while((p = strsep(&arg, whitespace_delims)) != NULL){
479
custom_argv = add_to_argv(custom_argv, &custom_argc, new_arg);
480
if (custom_argv == NULL){
481
perror("add_to_argv");
482
exitstatus = EXIT_FAILURE;
489
/* Check for harmful errors and go to fallback. Other errors might
490
not affect opening plugins */
491
if (errno == EMFILE or errno == ENFILE or errno == ENOMEM){
493
exitstatus = EXIT_FAILURE;
498
if(custom_argv != NULL){
499
custom_argv[0] = argv[0];
500
ret = argp_parse (&argp, custom_argc, custom_argv, 0, 0, &plugin_list);
501
if (ret == ARGP_ERR_UNKNOWN){
502
fprintf(stderr, "Unknown error while parsing arguments\n");
503
exitstatus = EXIT_FAILURE;
219
argp_parse (&argp, argc, argv, 0, 0, &plugin_list);
509
222
for(plugin *p = plugin_list; p != NULL; p=p->next){
615
ret = asprintf(&filename, "%s/%s", plugindir, dirst->d_name);
621
ret = stat(filename, &st);
301
char *filename = malloc(d_name_len + strlen(plugindir) + 2);
302
if (filename == NULL){
304
exitstatus =EXIT_FAILURE;
307
strcpy(filename, plugindir);
308
strcat(filename, "/");
309
strcat(filename, dirst->d_name);
628
313
if (not S_ISREG(st.st_mode) or (access(filename, X_OK) != 0)){
630
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
315
fprintf(stderr, "Ignoring plugin dir entry name \"%s\""
631
316
" with bad type or mode\n", filename);
320
if(getplugin(dirst->d_name, &plugin_list)->disabled){
322
fprintf(stderr, "Ignoring disabled plugin \"%s\"",
327
// Starting a new process to be watched
636
334
plugin *p = getplugin(dirst->d_name, &plugin_list);
644
fprintf(stderr, "Ignoring disabled plugin \"%s\"\n",
651
336
/* Add global arguments to argument list for this plugin */
652
337
plugin *g = getplugin(NULL, &plugin_list);
654
for(char **a = g->argv + 1; *a != NULL; a++){
655
if(not add_argument(p, *a)){
656
perror("add_argument");
659
/* Add global environment variables */
660
for(char **e = g->environ; *e != NULL; e++){
661
if(not add_environment(p, *e)){
662
perror("add_environment");
667
/* If this plugin has any environment variables, we will call
668
using execve and need to duplicate the environment from this
670
if(p->environ[0] != NULL){
671
for(char **e = environ; *e != NULL; e++){
672
char *copy = strdup(*e);
677
if(not add_environment(p, copy)){
678
perror("add_environment");
687
exitstatus = EXIT_FAILURE;
690
ret = set_cloexec_flag(pipefd[0]);
692
perror("set_cloexec_flag");
693
exitstatus = EXIT_FAILURE;
696
ret = set_cloexec_flag(pipefd[1]);
698
perror("set_cloexec_flag");
699
exitstatus = EXIT_FAILURE;
702
/* Block SIGCHLD until process is safely in process list */
703
ret = sigprocmask (SIG_BLOCK, &sigchld_action.sa_mask, NULL);
705
perror("sigprocmask");
706
exitstatus = EXIT_FAILURE;
709
// Starting a new process to be watched
338
for(char **a = g->argv + 1; *a != NULL; a++){
710
342
pid_t pid = fork();
713
exitstatus = EXIT_FAILURE;
717
344
/* this is the child process */
718
ret = sigaction(SIGCHLD, &old_sigchld_action, NULL);
723
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
725
perror("sigprocmask");
729
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 */
736
/* If dir has no file descriptor, we could not set FD_CLOEXEC
737
above and must now close it manually here. */
740
if(p->environ[0] == NULL){
741
if(execv(filename, p->argv) < 0){
746
if(execve(filename, p->argv, p->environ) < 0){
349
if(execv(filename, p->argv) < 0){
755
356
close(pipefd[1]); /* close unused write end of pipe */
756
357
process *new_process = malloc(sizeof(process));
757
358
if (new_process == NULL){
758
359
perror("malloc");
759
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
761
perror("sigprocmask");
763
exitstatus = EXIT_FAILURE;
767
*new_process = (struct process){ .pid = pid,
769
.next = process_list };
771
process_list = new_process;
772
/* Unblock SIGCHLD so signal handler can be run if this process
773
has already completed */
774
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
776
perror("sigprocmask");
777
exitstatus = EXIT_FAILURE;
360
exitstatus = EXIT_FAILURE;
364
new_process->fd = pipefd[0];
365
new_process->buffer = malloc(BUFFER_SIZE);
366
if (new_process->buffer == NULL){
368
exitstatus = EXIT_FAILURE;
371
new_process->buffer_size = BUFFER_SIZE;
372
new_process->buffer_length = 0;
781
373
FD_SET(new_process->fd, &rfds_all);
783
375
if (maxfd < new_process->fd){
784
376
maxfd = new_process->fd;
380
new_process->next = process_list;
381
process_list = new_process;
789
free_plugin_list(plugin_list);
794
if (process_list == NULL){
795
fprintf(stderr, "No plugin processes started. Incorrect plugin"
800
fd_set rfds = rfds_all;
801
int select_ret = select(maxfd+1, &rfds, NULL, NULL, NULL);
802
if (select_ret == -1){
804
exitstatus = EXIT_FAILURE;
807
/* OK, now either a process completed, or something can be read
809
for(process *proc = process_list; proc ; proc = proc->next){
810
/* Is this process completely done? */
811
if(proc->eof and proc->completed){
812
/* Only accept the plugin output if it exited cleanly */
813
if(not WIFEXITED(proc->status)
814
or WEXITSTATUS(proc->status) != 0){
815
/* Bad exit by plugin */
817
if(WIFEXITED(proc->status)){
818
fprintf(stderr, "Plugin %u exited with status %d\n",
819
(unsigned int) (proc->pid),
820
WEXITSTATUS(proc->status));
821
} else if(WIFSIGNALED(proc->status)) {
822
fprintf(stderr, "Plugin %u killed by signal %d\n",
823
(unsigned int) (proc->pid),
824
WTERMSIG(proc->status));
825
} else if(WCOREDUMP(proc->status)){
826
fprintf(stderr, "Plugin %d dumped core\n",
827
(unsigned int) (proc->pid));
830
/* Remove the plugin */
831
FD_CLR(proc->fd, &rfds_all);
832
/* Block signal while modifying process_list */
833
ret = sigprocmask (SIG_BLOCK, &sigchld_action.sa_mask, NULL);
835
perror("sigprocmask");
836
exitstatus = EXIT_FAILURE;
839
/* Delete this process entry from the list */
840
if(process_list == proc){
841
/* First one - simple */
842
process_list = proc->next;
844
/* Second one or later */
845
for(process *p = process_list; p != NULL; p = p->next){
847
p->next = proc->next;
386
if (process_list != NULL){
388
fd_set rfds = rfds_all;
389
int select_ret = select(maxfd+1, &rfds, NULL, NULL, NULL);
390
if (select_ret == -1){
394
for(process *process_itr = process_list; process_itr != NULL;
395
process_itr = process_itr->next){
396
if(FD_ISSET(process_itr->fd, &rfds)){
397
if(process_itr->buffer_length + BUFFER_SIZE
398
> process_itr->buffer_size){
399
process_itr->buffer = realloc(process_itr->buffer,
400
process_itr->buffer_size
401
+ (size_t) BUFFER_SIZE);
402
if (process_itr->buffer == NULL){
406
process_itr->buffer_size += BUFFER_SIZE;
408
ret = read(process_itr->fd, process_itr->buffer
409
+ process_itr->buffer_length, BUFFER_SIZE);
411
/* Read error from this process; ignore it */
414
process_itr->buffer_length += (size_t) ret;
417
/* wait for process exit */
419
waitpid(process_itr->pid, &status, 0);
420
if(WIFEXITED(status) and WEXITSTATUS(status) == 0){
421
for(size_t written = 0;
422
written < process_itr->buffer_length;){
423
ret = write(STDOUT_FILENO,
424
process_itr->buffer + written,
425
process_itr->buffer_length - written);
430
written += (size_t)ret;
434
FD_CLR(process_itr->fd, &rfds_all);
852
/* We are done modifying process list, so unblock signal */
853
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask,
856
perror("sigprocmask");
860
/* We deleted this process from the list, so we can't go
861
proc->next. Therefore, start over from the beginning of
865
/* This process exited nicely, so print its buffer */
867
bool bret = print_out_password(proc->buffer, proc->buffer_length);
869
perror("print_out_password");
870
exitstatus = EXIT_FAILURE;
874
/* This process has not completed. Does it have any output? */
875
if(proc->eof or not FD_ISSET(proc->fd, &rfds)){
876
/* This process had nothing to say at this time */
879
/* Before reading, make the process' data buffer large enough */
880
if(proc->buffer_length + BUFFER_SIZE > proc->buffer_size){
881
proc->buffer = realloc(proc->buffer, proc->buffer_size
882
+ (size_t) BUFFER_SIZE);
883
if (proc->buffer == NULL){
885
exitstatus = EXIT_FAILURE;
888
proc->buffer_size += BUFFER_SIZE;
890
/* Read from the process */
891
ret = read(proc->fd, proc->buffer + proc->buffer_length,
894
/* Read error from this process; ignore the error */
901
proc->buffer_length += (size_t) ret;
909
if(process_list == NULL or exitstatus != EXIT_SUCCESS){
910
/* Fallback if all plugins failed, none are found or an error occured */
912
fprintf(stderr, "Going to fallback mode using getpass(3)\n");
913
char *passwordbuffer = getpass("Password: ");
914
bret = print_out_password(passwordbuffer, strlen(passwordbuffer));
916
perror("print_out_password");
917
exitstatus = EXIT_FAILURE;
921
/* Restore old signal handler */
922
ret = sigaction(SIGCHLD, &old_sigchld_action, NULL);
925
exitstatus = EXIT_FAILURE;
928
if(custom_argv != NULL){
929
for(char **arg = custom_argv; *arg != NULL; arg++){
934
free_plugin_list(plugin_list);
940
/* Free the process list and kill the processes */
941
for(process *next; process_list != NULL; process_list = next){
942
next = process_list->next;
943
close(process_list->fd);
944
ret = kill(process_list->pid, SIGTERM);
945
if(ret == -1 and errno != ESRCH){
946
/* set-uid proccesses migth not get closed */
949
free(process_list->buffer);
953
/* Wait for any remaining child processes to terminate */
444
for(process *process_itr = process_list; process_itr != NULL;
445
process_itr = process_itr->next){
446
close(process_itr->fd);
447
kill(process_itr->pid, SIGTERM);
448
free(process_itr->buffer);
961
461
return exitstatus;