21
21
* Contact the authors at <mandos@fukt.bsnet.se>.
24
#include <stdio.h> /* popen, fileno */
25
#include <iso646.h> /* and, or, not */
26
#include <sys/types.h> /* DIR, opendir, stat, struct stat, waitpid,
27
WIFEXITED, WEXITSTATUS, wait */
28
#include <sys/wait.h> /* wait */
29
#include <dirent.h> /* DIR, opendir */
30
#include <sys/stat.h> /* stat, struct stat */
31
#include <unistd.h> /* stat, struct stat, chdir */
32
#include <stdlib.h> /* EXIT_FAILURE */
33
#include <sys/select.h> /* fd_set, select, FD_ZERO, FD_SET,
35
#include <string.h> /* strlen, strcpy, strcat */
36
#include <stdbool.h> /* true */
37
#include <sys/wait.h> /* waitpid, WIFEXITED, WEXITSTATUS */
38
#include <errno.h> /* errno */
39
#include <argp.h> /* argp */
24
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY() */
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() */
42
#include <iso646.h> /* and, or, not */
43
#include <dirent.h> /* DIR, struct dirent, opendir(),
44
readdir(), closedir(), dirfd() */
45
#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(), strcpy(),
56
#include <errno.h> /* errno */
57
#include <argp.h> /* struct argp_option, struct
58
argp_state, struct argp,
59
argp_parse(), ARGP_ERR_UNKNOWN,
60
ARGP_KEY_END, ARGP_KEY_ARG, error_t */
61
#include <signal.h> /* struct sigaction, sigemptyset(),
62
sigaddset(), sigaction(),
63
sigprocmask(), SIG_BLOCK, SIGCHLD,
64
SIG_UNBLOCK, kill() */
65
#include <errno.h> /* errno, EBADF */
67
#define BUFFER_SIZE 256
68
#define CONFFILE "/conf/conf.d/mandos/client.conf"
70
const char *argp_program_version = "mandos-client 1.0";
71
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
95
132
p->argv[p->argc] = NULL;
98
#define BUFFER_SIZE 256
100
const char *argp_program_version =
101
"plugbasedclient 0.9";
102
const char *argp_program_bug_address =
103
"<mandos@fukt.bsnet.se>";
105
"Mandos plugin runner -- Run Mandos plugins";
106
/* A description of the arguments we accept. */
107
static char args_doc[] = "";
136
* Based on the example in the GNU LibC manual chapter 13.13 "File
138
* *Note File Descriptor Flags:(libc)Descriptor Flags.
140
static int set_cloexec_flag(int fd)
142
int ret = fcntl(fd, F_GETFD, 0);
143
/* If reading the flags failed, return error indication now. */
147
/* Store modified flag word in the descriptor. */
148
return fcntl(fd, F_SETFD, ret | FD_CLOEXEC);
151
process *process_list = NULL;
153
/* Mark a process as completed when it exits, and save its exit
155
void handle_sigchld(__attribute__((unused)) int sig){
156
process *proc = process_list;
158
pid_t pid = wait(&status);
163
while(proc != NULL and proc->pid != pid){
167
/* Process not found in process list */
170
proc->status = status;
171
proc->completed = true;
174
bool print_out_password(const char *buffer, size_t length){
176
if(length>0 and buffer[length-1] == '\n'){
179
for(size_t written = 0; written < length; written += (size_t)ret){
180
ret = TEMP_FAILURE_RETRY(write(STDOUT_FILENO, buffer + written,
189
char ** addcustomargument(char **argv, int *argc, char *arg){
193
argv = malloc(sizeof(char*) * 2);
197
argv[0] = NULL; /* Will be set to argv[0] in main before parsing */
201
argv = realloc(argv, sizeof(char *)
202
* ((unsigned int) *argc + 1));
109
211
int main(int argc, char *argv[]){
110
char plugindir[] = "plugins.d";
111
size_t d_name_len, plugindir_len = sizeof(plugindir)-1;
212
const char *plugindir = "/conf/conf.d/mandos/plugins.d";
213
const char *conffile = CONFFILE;
113
217
struct dirent *dirst;
116
220
int ret, maxfd = 0;
117
process *process_list = NULL;
224
int exitstatus = EXIT_SUCCESS;
225
struct sigaction old_sigchld_action;
226
struct sigaction sigchld_action = { .sa_handler = handle_sigchld,
227
.sa_flags = SA_NOCLDSTOP };
228
char **custom_argv = NULL;
231
/* Establish a signal handler */
232
sigemptyset(&sigchld_action.sa_mask);
233
ret = sigaddset(&sigchld_action.sa_mask, SIGCHLD);
238
ret = sigaction(SIGCHLD, &sigchld_action, &old_sigchld_action);
119
244
/* The options we understand. */
120
245
struct argp_option options[] = {
121
246
{ .name = "global-options", .key = 'g',
122
.arg = "option[,option[,...]]", .flags = 0,
123
.doc = "Options effecting all plugins" },
247
.arg = "OPTION[,OPTION[,...]]",
248
.doc = "Options passed to all plugins" },
124
249
{ .name = "options-for", .key = 'o',
125
.arg = "plugin:option[,option[,...]]", .flags = 0,
126
.doc = "Options effecting only specified plugins" },
250
.arg = "PLUGIN:OPTION[,OPTION[,...]]",
251
.doc = "Options passed only to specified plugin" },
252
{ .name = "disable", .key = 'd',
254
.doc = "Disable a specific plugin", .group = 1 },
255
{ .name = "plugin-dir", .key = 128,
257
.doc = "Specify a different plugin directory", .group = 2 },
258
{ .name = "userid", .key = 129,
259
.arg = "ID", .flags = 0,
260
.doc = "User ID the plugins will run as", .group = 2 },
261
{ .name = "groupid", .key = 130,
262
.arg = "ID", .flags = 0,
263
.doc = "Group ID the plugins will run as", .group = 2 },
264
{ .name = "debug", .key = 131,
265
.doc = "Debug mode", .group = 3 },
130
269
error_t parse_opt (int key, char *arg, struct argp_state *state) {
131
/* Get the INPUT argument from `argp_parse', which we
132
know is a pointer to our arguments structure. */
270
/* Get the INPUT argument from `argp_parse', which we know is a
271
pointer to our plugin list pointer. */
133
272
plugin **plugins = state->input;
136
275
if (arg != NULL){
137
char *p = strtok(arg, ",");
139
addarguments(getplugin(NULL, plugins), p);
140
p = strtok(NULL, ",");
277
while((p = strsep(&arg, ",")) != NULL){
281
addargument(getplugin(NULL, plugins), p);
145
286
if (arg != NULL){
146
char *name = strtok(arg, ":");
147
char *p = strtok(NULL, ":");
150
addarguments(getplugin(name, plugins), p);
151
p = strtok(NULL, ",");
287
char *name = strsep(&arg, ":");
291
char *opt = strsep(&arg, ":");
297
while((p = strsep(&opt, ",")) != NULL){
301
addargument(getplugin(name, plugins), p);
308
getplugin(arg, plugins)->disabled = true;
315
uid = (uid_t)strtol(arg, NULL, 10);
318
gid = (gid_t)strtol(arg, NULL, 10);
155
323
case ARGP_KEY_ARG:
324
fprintf(stderr, "Ignoring unknown argument \"%s\"\n", arg);
158
326
case ARGP_KEY_END:
166
334
plugin *plugin_list = NULL;
168
336
struct argp argp = { .options = options, .parser = parse_opt,
169
.args_doc = args_doc, .doc = doc };
171
argp_parse (&argp, argc, argv, 0, 0, &plugin_list);
173
/* for(plugin *p = plugin_list; p != NULL; p=p->next){ */
174
/* fprintf(stderr, "Plugin: %s has %d arguments\n", p->name ? p->name : "Global", p->argc); */
175
/* for(char **a = p->argv + 1; *a != NULL; a++){ */
176
/* fprintf(stderr, "\tArg: %s\n", *a); */
337
.args_doc = "[+PLUS_SEPARATED_OPTIONS]",
338
.doc = "Mandos plugin runner -- Run plugins" };
340
ret = argp_parse (&argp, argc, argv, 0, 0, &plugin_list);
341
if (ret == ARGP_ERR_UNKNOWN){
342
fprintf(stderr, "Unknown error while parsing arguments\n");
343
exitstatus = EXIT_FAILURE;
347
conffp = fopen(conffile, "r");
349
char *org_line = NULL;
352
char *p, *arg, *new_arg, *line;
353
const char whitespace_delims[] = " \r\t\f\v\n";
354
const char comment_delim[] = "#";
357
sret = getline(&org_line, &size, conffp);
363
arg = strsep(&line, comment_delim);
364
while((p = strsep(&arg, whitespace_delims)) != NULL){
369
custom_argv = addcustomargument(custom_argv, &custom_argc, new_arg);
370
if (custom_argv == NULL){
371
perror("addcustomargument");
372
exitstatus = EXIT_FAILURE;
379
/* check for harmfull errors */
380
if (errno == EMFILE or errno == ENFILE or errno == ENOMEM){
382
exitstatus = EXIT_FAILURE;
387
if(custom_argv != NULL){
388
custom_argv[0] = argv[0];
389
ret = argp_parse (&argp, custom_argc, custom_argv, 0, 0, &plugin_list);
390
if (ret == ARGP_ERR_UNKNOWN){
391
fprintf(stderr, "Unknown error while parsing arguments\n");
392
exitstatus = EXIT_FAILURE;
398
for(plugin *p = plugin_list; p != NULL; p=p->next){
399
fprintf(stderr, "Plugin: %s has %d arguments\n",
400
p->name ? p->name : "Global", p->argc - 1);
401
for(char **a = p->argv; *a != NULL; a++){
402
fprintf(stderr, "\tArg: %s\n", *a);
182
417
dir = opendir(plugindir);
185
fprintf(stderr, "Can not open directory\n");
419
perror("Could not open plugin dir");
420
exitstatus = EXIT_FAILURE;
424
/* Set the FD_CLOEXEC flag on the directory, if possible */
426
int dir_fd = dirfd(dir);
428
ret = set_cloexec_flag(dir_fd);
430
perror("set_cloexec_flag");
431
exitstatus = EXIT_FAILURE;
192
440
dirst = readdir(dir);
194
442
// All directory entries have been processed
195
443
if(dirst == NULL){
446
exitstatus = EXIT_FAILURE;
199
452
d_name_len = strlen(dirst->d_name);
201
// Ignore dotfiles and backup files
202
if (dirst->d_name[0] == '.'
203
or dirst->d_name[d_name_len - 1] == '~'){
207
char *filename = malloc(d_name_len + plugindir_len + 2);
208
strcpy(filename, plugindir);
209
strcat(filename, "/");
210
strcat(filename, dirst->d_name);
214
if (S_ISREG(st.st_mode) and (access(filename, X_OK) == 0)){
215
// Starting a new process to be watched
216
process *new_process = malloc(sizeof(process));
223
new_process->pid = fork();
224
if(new_process->pid == 0){
225
/* this is the child process */
454
// Ignore dotfiles, backup files and other junk
456
bool bad_name = false;
458
const char const *bad_prefixes[] = { ".", "#", NULL };
460
const char const *bad_suffixes[] = { "~", "#", ".dpkg-new",
462
".dpkg-divert", NULL };
463
for(const char **pre = bad_prefixes; *pre != NULL; pre++){
464
size_t pre_len = strlen(*pre);
465
if((d_name_len >= pre_len)
466
and strncmp((dirst->d_name), *pre, pre_len) == 0){
468
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
469
" with bad prefix %s\n", dirst->d_name, *pre);
480
for(const char **suf = bad_suffixes; *suf != NULL; suf++){
481
size_t suf_len = strlen(*suf);
482
if((d_name_len >= suf_len)
483
and (strcmp((dirst->d_name)+d_name_len-suf_len, *suf)
486
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
487
" with bad suffix %s\n", dirst->d_name, *suf);
499
char *filename = malloc(d_name_len + strlen(plugindir) + 2);
500
if (filename == NULL){
504
strcpy(filename, plugindir); /* Spurious warning */
505
strcat(filename, "/"); /* Spurious warning */
506
strcat(filename, dirst->d_name); /* Spurious warning */
508
ret = stat(filename, &st);
515
if (not S_ISREG(st.st_mode) or (access(filename, X_OK) != 0)){
517
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
518
" with bad type or mode\n", filename);
523
if(getplugin(dirst->d_name, &plugin_list)->disabled){
525
fprintf(stderr, "Ignoring disabled plugin \"%s\"\n",
531
plugin *p = getplugin(dirst->d_name, &plugin_list);
533
/* Add global arguments to argument list for this plugin */
534
plugin *g = getplugin(NULL, &plugin_list);
535
for(char **a = g->argv + 1; *a != NULL; a++){
543
exitstatus = EXIT_FAILURE;
546
ret = set_cloexec_flag(pipefd[0]);
548
perror("set_cloexec_flag");
549
exitstatus = EXIT_FAILURE;
552
ret = set_cloexec_flag(pipefd[1]);
554
perror("set_cloexec_flag");
555
exitstatus = EXIT_FAILURE;
558
/* Block SIGCHLD until process is safely in process list */
559
ret = sigprocmask (SIG_BLOCK, &sigchld_action.sa_mask, NULL);
561
perror("sigprocmask");
562
exitstatus = EXIT_FAILURE;
565
// Starting a new process to be watched
569
exitstatus = EXIT_FAILURE;
573
/* this is the child process */
574
ret = sigaction(SIGCHLD, &old_sigchld_action, NULL);
579
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
581
perror("sigprocmask");
585
ret = dup2(pipefd[1], STDOUT_FILENO); /* replace our stdout */
592
/* If dir has no file descriptor, we could not set FD_CLOEXEC
593
above and must now close it manually here. */
227
close(pipefd[0]); /* close unused read end of pipe */
228
dup2(pipefd[1], STDOUT_FILENO); /* replace our stdout */
230
basename = strrchr(filename, '/');
231
if (basename == NULL){
236
plugin *p = getplugin(basename, &plugin_list);
238
plugin *g = getplugin(NULL, &plugin_list);
239
for(char **a = g->argv + 1; *a != NULL; a++){
242
if(execv(filename, p->argv) < 0){
249
close(pipefd[1]); /* close unused write end of pipe */
250
new_process->fd = pipefd[0];
251
new_process->buffer = malloc(BUFFER_SIZE);
252
if (new_process->buffer == NULL){
256
new_process->buffer_size = BUFFER_SIZE;
257
new_process->buffer_length = 0;
258
FD_SET(new_process->fd, &rfds_orig);
260
if (maxfd < new_process->fd){
261
maxfd = new_process->fd;
265
new_process->next = process_list;
266
process_list = new_process;
596
if(execv(filename, p->argv) < 0){
604
close(pipefd[1]); /* close unused write end of pipe */
605
process *new_process = malloc(sizeof(process));
606
if (new_process == NULL){
608
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
610
perror("sigprocmask");
612
exitstatus = EXIT_FAILURE;
616
*new_process = (struct process){ .pid = pid,
618
.next = process_list };
620
process_list = new_process;
621
/* Unblock SIGCHLD so signal handler can be run if this process
622
has already completed */
623
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
625
perror("sigprocmask");
626
exitstatus = EXIT_FAILURE;
630
FD_SET(new_process->fd, &rfds_all);
632
if (maxfd < new_process->fd){
633
maxfd = new_process->fd;
638
/* Free the plugin list */
639
for(plugin *next; plugin_list != NULL; plugin_list = next){
640
next = plugin_list->next;
641
free(plugin_list->argv);
272
if (process_list != NULL){
274
fd_set rfds = rfds_orig;
275
int select_ret = select(maxfd+1, &rfds, NULL, NULL, NULL);
276
if (select_ret == -1){
280
for(process *process_itr = process_list; process_itr != NULL;
281
process_itr = process_itr->next){
282
if(FD_ISSET(process_itr->fd, &rfds)){
283
if(process_itr->buffer_length + BUFFER_SIZE
284
> process_itr->buffer_size){
285
process_itr->buffer = realloc(process_itr->buffer,
286
process_itr->buffer_size
287
+ (size_t) BUFFER_SIZE);
288
if (process_itr->buffer == NULL){
292
process_itr->buffer_size += BUFFER_SIZE;
294
ret = read(process_itr->fd, process_itr->buffer
295
+ process_itr->buffer_length, BUFFER_SIZE);
297
/* Read error from this process; ignore it */
300
process_itr->buffer_length += (size_t) ret;
303
/* wait for process exit */
305
waitpid(process_itr->pid, &status, 0);
306
if(WIFEXITED(status) and WEXITSTATUS(status) == 0){
307
for(size_t written = 0;
308
written < process_itr->buffer_length;){
309
ret = write(STDOUT_FILENO,
310
process_itr->buffer + written,
311
process_itr->buffer_length - written);
316
written += (size_t)ret;
320
FD_CLR(process_itr->fd, &rfds_orig);
648
if (process_list == NULL){
649
fprintf(stderr, "No plugin processes started. Incorrect plugin"
654
fd_set rfds = rfds_all;
655
int select_ret = select(maxfd+1, &rfds, NULL, NULL, NULL);
656
if (select_ret == -1){
658
exitstatus = EXIT_FAILURE;
661
/* OK, now either a process completed, or something can be read
663
for(process *proc = process_list; proc ; proc = proc->next){
664
/* Is this process completely done? */
665
if(proc->eof and proc->completed){
666
/* Only accept the plugin output if it exited cleanly */
667
if(not WIFEXITED(proc->status)
668
or WEXITSTATUS(proc->status) != 0){
669
/* Bad exit by plugin */
671
if(WIFEXITED(proc->status)){
672
fprintf(stderr, "Plugin %u exited with status %d\n",
673
(unsigned int) (proc->pid),
674
WEXITSTATUS(proc->status));
675
} else if(WIFSIGNALED(proc->status)) {
676
fprintf(stderr, "Plugin %u killed by signal %d\n",
677
(unsigned int) (proc->pid),
678
WTERMSIG(proc->status));
679
} else if(WCOREDUMP(proc->status)){
680
fprintf(stderr, "Plugin %d dumped core\n",
681
(unsigned int) (proc->pid));
684
/* Remove the plugin */
685
FD_CLR(proc->fd, &rfds_all);
686
/* Block signal while modifying process_list */
687
ret = sigprocmask (SIG_BLOCK, &sigchld_action.sa_mask, NULL);
689
perror("sigprocmask");
690
exitstatus = EXIT_FAILURE;
693
/* Delete this process entry from the list */
694
if(process_list == proc){
695
/* First one - simple */
696
process_list = proc->next;
698
/* Second one or later */
699
for(process *p = process_list; p != NULL; p = p->next){
701
p->next = proc->next;
706
/* We are done modifying process list, so unblock signal */
707
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask,
710
perror("sigprocmask");
714
/* We deleted this process from the list, so we can't go
715
proc->next. Therefore, start over from the beginning of
719
/* This process exited nicely, so print its buffer */
721
bool bret = print_out_password(proc->buffer, proc->buffer_length);
723
perror("print_out_password");
724
exitstatus = EXIT_FAILURE;
728
/* This process has not completed. Does it have any output? */
729
if(proc->eof or not FD_ISSET(proc->fd, &rfds)){
730
/* This process had nothing to say at this time */
733
/* Before reading, make the process' data buffer large enough */
734
if(proc->buffer_length + BUFFER_SIZE > proc->buffer_size){
735
proc->buffer = realloc(proc->buffer, proc->buffer_size
736
+ (size_t) BUFFER_SIZE);
737
if (proc->buffer == NULL){
739
exitstatus = EXIT_FAILURE;
742
proc->buffer_size += BUFFER_SIZE;
744
/* Read from the process */
745
ret = read(proc->fd, proc->buffer + proc->buffer_length,
748
/* Read error from this process; ignore the error */
755
proc->buffer_length += (size_t) ret;
330
for(process *process_itr = process_list; process_itr != NULL;
331
process_itr = process_itr->next){
332
close(process_itr->fd);
333
kill(process_itr->pid, SIGTERM);
334
free(process_itr->buffer);
763
if(process_list == NULL or exitstatus != EXIT_SUCCESS){
764
/* Fallback if all plugins failed, none are found or an error occured */
766
fprintf(stderr, "Going to fallback mode using getpass(3)\n");
767
char *passwordbuffer = getpass("Password: ");
768
bret = print_out_password(passwordbuffer, strlen(passwordbuffer));
770
perror("print_out_password");
771
exitstatus = EXIT_FAILURE;
776
/* Restore old signal handler */
777
sigaction(SIGCHLD, &old_sigchld_action, NULL);
781
/* Free the plugin list */
782
for(plugin *next; plugin_list != NULL; plugin_list = next){
783
next = plugin_list->next;
784
free(plugin_list->argv);
792
/* Free the process list and kill the processes */
793
for(process *next; process_list != NULL; process_list = next){
794
next = process_list->next;
795
close(process_list->fd);
796
ret = kill(process_list->pid, SIGTERM);
797
if(ret == -1 and errno != ESRCH){
798
/* set-uid proccesses migth not get closed */
801
free(process_list->buffer);
805
/* Wait for any remaining child processes to terminate */