3
3
* Mandos plugin runner - Run Mandos plugins
5
* Copyright © 2007-2008 Teddy Hogeborn & Björn Påhlsson
5
* Copyright © 2008,2009 Teddy Hogeborn
6
* Copyright © 2008,2009 Björn Påhlsson
7
8
* This program is free software: you can redistribute it and/or
8
9
* modify it under the terms of the GNU General Public License as
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,
61
62
#include <signal.h> /* struct sigaction, sigemptyset(),
62
63
sigaddset(), sigaction(),
63
64
sigprocmask(), SIG_BLOCK, SIGCHLD,
64
SIG_UNBLOCK, kill() */
65
SIG_UNBLOCK, kill(), sig_atomic_t
65
67
#include <errno.h> /* errno, EBADF */
68
#include <inttypes.h> /* intmax_t, PRIdMAX, strtoimax() */
67
70
#define BUFFER_SIZE 256
69
72
#define PDIR "/lib/mandos/plugins.d"
70
73
#define AFILE "/conf/conf.d/mandos/plugin-runner.conf"
72
const char *argp_program_version = "plugin-runner 1.0";
75
const char *argp_program_version = "plugin-runner " VERSION;
73
76
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
77
78
typedef struct plugin{
78
79
char *name; /* can be NULL or any plugin name */
89
90
size_t buffer_size;
90
91
size_t buffer_length;
92
volatile bool completed;
93
volatile sig_atomic_t completed;
94
95
struct plugin *next;
97
98
static plugin *plugin_list = NULL;
99
/* Gets a existing plugin based on name,
100
/* Gets an existing plugin based on name,
100
101
or if none is found, creates a new one */
101
102
static plugin *getplugin(char *name){
102
103
/* Check for exiting plugin with that name */
103
for (plugin *p = plugin_list; p != NULL; p = p->next){
104
if ((p->name == name)
105
or (p->name and name and (strcmp(p->name, name) == 0))){
104
for(plugin *p = plugin_list; p != NULL; p = p->next){
106
or (p->name and name and (strcmp(p->name, name) == 0))){
109
110
/* Create a new plugin */
110
111
plugin *new_plugin = malloc(sizeof(plugin));
111
if (new_plugin == NULL){
112
if(new_plugin == NULL){
114
115
char *copy_name = NULL;
115
116
if(name != NULL){
116
117
copy_name = strdup(name);
117
118
if(copy_name == NULL){
122
*new_plugin = (plugin) { .name = copy_name,
125
.next = plugin_list };
124
*new_plugin = (plugin){ .name = copy_name,
127
.next = plugin_list };
127
129
new_plugin->argv = malloc(sizeof(char *) * 2);
128
if (new_plugin->argv == NULL){
130
if(new_plugin->argv == NULL){
130
132
free(new_plugin);
133
135
new_plugin->argv[0] = copy_name;
134
136
new_plugin->argv[1] = NULL;
136
138
new_plugin->environ = malloc(sizeof(char *));
137
139
if(new_plugin->environ == NULL){
181
183
/* Add to a plugin's environment */
182
static bool add_environment(plugin *p, const char *def){
184
static bool add_environment(plugin *p, const char *def, bool replace){
188
/* namelen = length of name of environment variable */
189
size_t namelen = (size_t)(strchrnul(def, '=') - def);
190
/* Search for this environment variable */
191
for(char **e = p->environ; *e != NULL; e++){
192
if(strncmp(*e, def, namelen + 1) == 0){
193
/* It already exists */
195
char *new = realloc(*e, strlen(def) + 1);
186
205
return add_to_char_array(def, &(p->environ), &(p->envc));
191
210
* Descriptor Flags".
192
211
* *Note File Descriptor Flags:(libc)Descriptor Flags.
194
static int set_cloexec_flag(int fd)
213
static int set_cloexec_flag(int fd){
196
214
int ret = fcntl(fd, F_GETFD, 0);
197
215
/* If reading the flags failed, return error indication now. */
233
252
proc->status = status;
234
proc->completed = true;
238
258
/* Prints out a password to stdout */
239
bool print_out_password(const char *buffer, size_t length){
259
static bool print_out_password(const char *buffer, size_t length){
241
if(length>0 and buffer[length-1] == '\n'){
244
261
for(size_t written = 0; written < length; written += (size_t)ret){
245
262
ret = TEMP_FAILURE_RETRY(write(STDOUT_FILENO, buffer + written,
246
263
length - written));
327
346
{ .name = "global-options", .key = 'g',
328
347
.arg = "OPTION[,OPTION[,...]]",
329
348
.doc = "Options passed to all plugins" },
330
{ .name = "global-envs", .key = 'e',
349
{ .name = "global-env", .key = 'G',
331
350
.arg = "VAR=value",
332
351
.doc = "Environment variable passed to all plugins" },
333
352
{ .name = "options-for", .key = 'o',
334
353
.arg = "PLUGIN:OPTION[,OPTION[,...]]",
335
354
.doc = "Options passed only to specified plugin" },
336
{ .name = "envs-for", .key = 'f',
355
{ .name = "env-for", .key = 'E',
337
356
.arg = "PLUGIN:ENV=value",
338
357
.doc = "Environment variable passed to specified plugin" },
339
358
{ .name = "disable", .key = 'd',
341
360
.doc = "Disable a specific plugin", .group = 1 },
361
{ .name = "enable", .key = 'e',
363
.doc = "Enable a specific plugin", .group = 1 },
342
364
{ .name = "plugin-dir", .key = 128,
343
365
.arg = "DIRECTORY",
344
366
.doc = "Specify a different plugin directory", .group = 2 },
359
error_t parse_opt (int key, char *arg, __attribute__((unused))
360
struct argp_state *state) {
361
/* Get the INPUT argument from `argp_parse', which we know is a
362
pointer to our plugin list pointer. */
381
error_t parse_opt(int key, char *arg, __attribute__((unused))
382
struct argp_state *state){
364
385
case 'g': /* --global-options */
367
while((p = strsep(&arg, ",")) != NULL){
388
while((plugin_option = strsep(&arg, ",")) != NULL){
389
if(plugin_option[0] == '\0'){
371
if(not add_argument(getplugin(NULL), p)){
392
if(not add_argument(getplugin(NULL), plugin_option)){
372
393
perror("add_argument");
373
394
return ARGP_ERR_UNKNOWN;
378
case 'e': /* --global-envs */
399
case 'G': /* --global-env */
383
char *envdef = strdup(arg);
387
if(not add_environment(getplugin(NULL), envdef)){
388
perror("add_environment");
403
if(not add_environment(getplugin(NULL), arg, true)){
404
perror("add_environment");
392
407
case 'o': /* --options-for */
394
char *p_name = strsep(&arg, ":");
395
if(p_name[0] == '\0'){
398
char *opt = strsep(&arg, ":");
404
while((p = strsep(&opt, ",")) != NULL){
408
if(not add_argument(getplugin(p_name), p)){
409
perror("add_argument");
410
return ARGP_ERR_UNKNOWN;
409
char *plugin_name = strsep(&arg, ":");
410
if(plugin_name[0] == '\0'){
414
while((plugin_option = strsep(&arg, ",")) != NULL){
415
if(not add_argument(getplugin(plugin_name), plugin_option)){
416
perror("add_argument");
417
return ARGP_ERR_UNKNOWN;
416
case 'f': /* --envs-for */
422
case 'E': /* --env-for */
422
428
if(envdef == NULL){
425
char *p_name = strndup(arg, (size_t) (envdef-arg));
430
if(not add_environment(getplugin(p_name), envdef)){
432
if(not add_environment(getplugin(arg), envdef+1, true)){
431
433
perror("add_environment");
435
437
case 'd': /* --disable */
437
439
plugin *p = getplugin(arg);
439
441
return ARGP_ERR_UNKNOWN;
441
443
p->disabled = true;
446
case 'e': /* --enable */
448
plugin *p = getplugin(arg);
450
return ARGP_ERR_UNKNOWN;
444
455
case 128: /* --plugin-dir */
445
457
plugindir = strdup(arg);
446
458
if(plugindir == NULL){
447
459
perror("strdup");
450
462
case 129: /* --config-file */
463
/* This is already done by parse_opt_config_file() */
465
case 130: /* --userid */
467
tmpmax = strtoimax(arg, &tmp, 10);
468
if(errno != 0 or tmp == arg or *tmp != '\0'
469
or tmpmax != (uid_t)tmpmax){
470
fprintf(stderr, "Bad user ID number: \"%s\", using %"
471
PRIdMAX "\n", arg, (intmax_t)uid);
476
case 131: /* --groupid */
478
tmpmax = strtoimax(arg, &tmp, 10);
479
if(errno != 0 or tmp == arg or *tmp != '\0'
480
or tmpmax != (gid_t)tmpmax){
481
fprintf(stderr, "Bad group ID number: \"%s\", using %"
482
PRIdMAX "\n", arg, (intmax_t)gid);
487
case 132: /* --debug */
491
* When adding more options before this line, remember to also add a
492
* "case" to the "parse_opt_config_file" function below.
495
/* Cryptsetup always passes an argument, which is an empty
496
string if "none" was specified in /etc/crypttab. So if
497
argument was empty, we ignore it silently. */
499
fprintf(stderr, "Ignoring unknown argument \"%s\"\n", arg);
505
return ARGP_ERR_UNKNOWN;
510
/* This option parser is the same as parse_opt() above, except it
511
ignores everything but the --config-file option. */
512
error_t parse_opt_config_file(int key, char *arg,
513
__attribute__((unused))
514
struct argp_state *state){
516
case 'g': /* --global-options */
517
case 'G': /* --global-env */
518
case 'o': /* --options-for */
519
case 'E': /* --env-for */
520
case 'd': /* --disable */
521
case 'e': /* --enable */
522
case 128: /* --plugin-dir */
524
case 129: /* --config-file */
451
526
argfile = strdup(arg);
452
527
if(argfile == NULL){
453
528
perror("strdup");
456
531
case 130: /* --userid */
457
uid = (uid_t)strtol(arg, NULL, 10);
459
532
case 131: /* --groupid */
460
gid = (gid_t)strtol(arg, NULL, 10);
462
533
case 132: /* --debug */
465
534
case ARGP_KEY_ARG:
466
fprintf(stderr, "Ignoring unknown argument \"%s\"\n", arg);
468
535
case ARGP_KEY_END:
476
struct argp argp = { .options = options, .parser = parse_opt,
477
.args_doc = "[+PLUS_SEPARATED_OPTIONS]",
543
struct argp argp = { .options = options,
544
.parser = parse_opt_config_file,
478
546
.doc = "Mandos plugin runner -- Run plugins" };
480
ret = argp_parse (&argp, argc, argv, 0, 0, NULL);
481
if (ret == ARGP_ERR_UNKNOWN){
548
/* Parse using parse_opt_config_file() in order to get the custom
549
config file location, if any. */
550
ret = argp_parse(&argp, argc, argv, ARGP_IN_ORDER, 0, NULL);
551
if(ret == ARGP_ERR_UNKNOWN){
482
552
fprintf(stderr, "Unknown error while parsing arguments\n");
483
553
exitstatus = EXIT_FAILURE;
487
/* Opens the configfile if aviable */
488
if (argfile == NULL){
557
/* Reset to the normal argument parser */
558
argp.parser = parse_opt;
560
/* Open the configfile if available */
489
562
conffp = fopen(AFILE, "r");
491
564
conffp = fopen(argfile, "r");
556
628
/* If there was any arguments from configuration file,
557
629
pass them to parser as command arguments */
558
630
if(custom_argv != NULL){
559
ret = argp_parse (&argp, custom_argc, custom_argv, 0, 0, NULL);
560
if (ret == ARGP_ERR_UNKNOWN){
631
ret = argp_parse(&argp, custom_argc, custom_argv, ARGP_IN_ORDER,
633
if(ret == ARGP_ERR_UNKNOWN){
561
634
fprintf(stderr, "Unknown error while parsing arguments\n");
562
635
exitstatus = EXIT_FAILURE;
640
/* Parse actual command line arguments, to let them override the
642
ret = argp_parse(&argp, argc, argv, ARGP_IN_ORDER, 0, NULL);
643
if(ret == ARGP_ERR_UNKNOWN){
644
fprintf(stderr, "Unknown error while parsing arguments\n");
645
exitstatus = EXIT_FAILURE;
568
650
for(plugin *p = plugin_list; p != NULL; p=p->next){
569
651
fprintf(stderr, "Plugin: %s has %d arguments\n",
571
653
for(char **a = p->argv; *a != NULL; a++){
572
654
fprintf(stderr, "\tArg: %s\n", *a);
574
fprintf(stderr, "...and %u environment variables\n", p->envc);
656
fprintf(stderr, "...and %d environment variables\n", p->envc);
575
657
for(char **a = p->environ; *a != NULL; a++){
576
658
fprintf(stderr, "\t%s\n", *a);
581
663
/* Strip permissions down to nobody */
582
668
ret = setuid(uid);
584
670
perror("setuid");
591
if (plugindir == NULL){
673
if(plugindir == NULL){
592
674
dir = opendir(PDIR);
594
676
dir = opendir(plugindir);
678
ret = asprintf(&filename, "%s/%s", plugindir, dirst->d_name);
761
if(plugindir == NULL){
762
ret = asprintf(&filename, PDIR "/%s", dirst->d_name);
764
ret = asprintf(&filename, "%s/%s", plugindir, dirst->d_name);
680
767
perror("asprintf");
684
771
ret = stat(filename, &st);
691
778
/* Ignore non-executable files */
692
if (not S_ISREG(st.st_mode) or (access(filename, X_OK) != 0)){
779
if(not S_ISREG(st.st_mode) or (access(filename, X_OK) != 0)){
694
781
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
695
782
" with bad type or mode\n", filename);
724
811
/* Add global environment variables */
725
812
for(char **e = g->environ; *e != NULL; e++){
726
if(not add_environment(p, *e)){
813
if(not add_environment(p, *e, false)){
727
814
perror("add_environment");
735
822
if(p->environ[0] != NULL){
736
823
for(char **e = environ; *e != NULL; e++){
737
char *copy = strdup(*e);
742
if(not add_environment(p, copy)){
824
if(not add_environment(p, *e, false)){
743
825
perror("add_environment");
768
850
/* Block SIGCHLD until process is safely in process list */
769
ret = sigprocmask (SIG_BLOCK, &sigchld_action.sa_mask, NULL);
851
ret = sigprocmask(SIG_BLOCK, &sigchld_action.sa_mask, NULL);
771
853
perror("sigprocmask");
772
854
exitstatus = EXIT_FAILURE;
775
// Starting a new process to be watched
857
/* Starting a new process to be watched */
776
858
pid_t pid = fork();
863
945
free_plugin_list();
867
949
/* Main loop while running plugins exist */
868
950
while(plugin_list){
869
951
fd_set rfds = rfds_all;
870
952
int select_ret = select(maxfd+1, &rfds, NULL, NULL, NULL);
871
if (select_ret == -1){
953
if(select_ret == -1){
872
954
perror("select");
873
955
exitstatus = EXIT_FAILURE;
876
958
/* OK, now either a process completed, or something can be read
877
959
from one of them */
878
for(plugin *proc = plugin_list; proc != NULL; proc = proc->next){
960
for(plugin *proc = plugin_list; proc != NULL;){
879
961
/* Is this process completely done? */
880
if(proc->eof and proc->completed){
962
if(proc->completed and proc->eof){
881
963
/* Only accept the plugin output if it exited cleanly */
882
964
if(not WIFEXITED(proc->status)
883
965
or WEXITSTATUS(proc->status) != 0){
884
966
/* Bad exit by plugin */
887
969
if(WIFEXITED(proc->status)){
888
fprintf(stderr, "Plugin %u exited with status %d\n",
889
(unsigned int) (proc->pid),
970
fprintf(stderr, "Plugin %s [%" PRIdMAX "] exited with"
971
" status %d\n", proc->name,
972
(intmax_t) (proc->pid),
890
973
WEXITSTATUS(proc->status));
891
} else if(WIFSIGNALED(proc->status)) {
892
fprintf(stderr, "Plugin %u killed by signal %d\n",
893
(unsigned int) (proc->pid),
974
} else if(WIFSIGNALED(proc->status)){
975
fprintf(stderr, "Plugin %s [%" PRIdMAX "] killed by"
976
" signal %d\n", proc->name,
977
(intmax_t) (proc->pid),
894
978
WTERMSIG(proc->status));
895
979
} else if(WCOREDUMP(proc->status)){
896
fprintf(stderr, "Plugin %d dumped core\n",
897
(unsigned int) (proc->pid));
980
fprintf(stderr, "Plugin %s [%" PRIdMAX "] dumped"
981
" core\n", proc->name, (intmax_t) (proc->pid));
901
985
/* Remove the plugin */
902
986
FD_CLR(proc->fd, &rfds_all);
904
988
/* Block signal while modifying process_list */
905
989
ret = sigprocmask(SIG_BLOCK, &sigchld_action.sa_mask, NULL);
908
992
exitstatus = EXIT_FAILURE;
996
plugin *next_plugin = proc->next;
911
997
free_plugin(proc);
912
1000
/* We are done modifying process list, so unblock signal */
913
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask,
1001
ret = sigprocmask(SIG_UNBLOCK, &sigchld_action.sa_mask,
916
1004
perror("sigprocmask");
917
1005
exitstatus = EXIT_FAILURE;
938
1027
/* This process has not completed. Does it have any output? */
939
1028
if(proc->eof or not FD_ISSET(proc->fd, &rfds)){
940
1029
/* This process had nothing to say at this time */
943
1033
/* Before reading, make the process' data buffer large enough */
944
1034
if(proc->buffer_length + BUFFER_SIZE > proc->buffer_size){
945
1035
proc->buffer = realloc(proc->buffer, proc->buffer_size
946
1036
+ (size_t) BUFFER_SIZE);
947
if (proc->buffer == NULL){
1037
if(proc->buffer == NULL){
948
1038
perror("malloc");
949
1039
exitstatus = EXIT_FAILURE;
952
1042
proc->buffer_size += BUFFER_SIZE;
954
1044
/* Read from the process */
955
ret = read(proc->fd, proc->buffer + proc->buffer_length,
1045
sret = read(proc->fd, proc->buffer + proc->buffer_length,
958
1048
/* Read error from this process; ignore the error */
963
1054
proc->eof = true;
965
proc->buffer_length += (size_t) ret;
1056
proc->buffer_length += (size_t) sret;
973
1064
if(plugin_list == NULL or exitstatus != EXIT_SUCCESS){
977
1068
fprintf(stderr, "Going to fallback mode using getpass(3)\n");
978
1069
char *passwordbuffer = getpass("Password: ");
979
bret = print_out_password(passwordbuffer, strlen(passwordbuffer));
1070
size_t len = strlen(passwordbuffer);
1071
/* Strip trailing newline */
1072
if(len > 0 and passwordbuffer[len-1] == '\n'){
1073
passwordbuffer[len-1] = '\0'; /* not strictly necessary */
1076
bret = print_out_password(passwordbuffer, len);
981
1078
perror("print_out_password");
982
1079
exitstatus = EXIT_FAILURE;