1
#include <stdio.h> /* popen, fileno */
2
#include <iso646.h> /* and, or, not */
3
#include <sys/types.h> /* DIR, opendir, stat, struct stat, waitpid,
4
WIFEXITED, WEXITSTATUS, wait */
5
#include <sys/wait.h> /* wait */
6
#include <dirent.h> /* DIR, opendir */
7
#include <sys/stat.h> /* stat, struct stat */
8
#include <unistd.h> /* stat, struct stat, chdir */
9
#include <stdlib.h> /* EXIT_FAILURE */
10
#include <sys/select.h> /* fd_set, select, FD_ZERO, FD_SET, FD_ISSET */
11
#include <string.h> /* strlen, strcpy, strcat */
12
#include <stdbool.h> /* true */
13
#include <sys/wait.h> /* waitpid, WIFEXITED, WEXITSTATUS */
14
#include <errno.h> /* errno */
1
/* -*- coding: utf-8 -*- */
3
* Mandos plugin runner - Run Mandos plugins
5
* Copyright © 2007-2008 Teddy Hogeborn & Björn Påhlsson
7
* This program is free software: you can redistribute it and/or
8
* modify it under the terms of the GNU General Public License as
9
* published by the Free Software Foundation, either version 3 of the
10
* License, or (at your option) any later version.
12
* This program is distributed in the hope that it will be useful, but
13
* WITHOUT ANY WARRANTY; without even the implied warranty of
14
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15
* General Public License for more details.
17
* You should have received a copy of the GNU General Public License
18
* along with this program. If not, see
19
* <http://www.gnu.org/licenses/>.
21
* Contact the authors at <mandos@fukt.bsnet.se>.
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> /* strtok, 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
69
const char *argp_program_version = "mandos-client 1.0";
70
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
24
83
struct process *next;
27
#define BUFFER_SIZE 256
86
typedef struct plugin{
87
char *name; /* can be NULL or any plugin name */
94
static plugin *getplugin(char *name, plugin **plugin_list){
95
for (plugin *p = *plugin_list; p != NULL; p = p->next){
97
or (p->name and name and (strcmp(p->name, name) == 0))){
101
/* Create a new plugin */
102
plugin *new_plugin = malloc(sizeof(plugin));
103
if (new_plugin == NULL){
107
new_plugin->name = name;
108
new_plugin->argv = malloc(sizeof(char *) * 2);
109
if (new_plugin->argv == NULL){
113
new_plugin->argv[0] = name;
114
new_plugin->argv[1] = NULL;
115
new_plugin->argc = 1;
116
new_plugin->disabled = false;
117
new_plugin->next = *plugin_list;
118
/* Append the new plugin to the list */
119
*plugin_list = new_plugin;
123
static void addargument(plugin *p, char *arg){
124
p->argv[p->argc] = arg;
125
p->argv = realloc(p->argv, sizeof(char *) * (size_t)(p->argc + 2));
126
if (p->argv == NULL){
131
p->argv[p->argc] = NULL;
135
* Based on the example in the GNU LibC manual chapter 13.13 "File
137
* *Note File Descriptor Flags:(libc)Descriptor Flags.
139
static int set_cloexec_flag(int fd)
141
int ret = fcntl(fd, F_GETFD, 0);
142
/* If reading the flags failed, return error indication now. */
146
/* Store modified flag word in the descriptor. */
147
return fcntl(fd, F_SETFD, ret | FD_CLOEXEC);
150
process *process_list = NULL;
152
/* Mark a process as completed when it exits, and save its exit
154
void handle_sigchld(__attribute__((unused)) int sig){
155
process *proc = process_list;
157
pid_t pid = wait(&status);
162
while(proc != NULL and proc->pid != pid){
166
/* Process not found in process list */
169
proc->status = status;
170
proc->completed = true;
173
bool print_out_password(const char *buffer, size_t length){
175
if(length>0 and buffer[length-1] == '\n'){
178
for(size_t written = 0; written < length; written += (size_t)ret){
179
ret = TEMP_FAILURE_RETRY(write(STDOUT_FILENO, buffer + written,
29
188
int main(int argc, char *argv[]){
30
char plugindir[] = "plugins.d";
31
size_t d_name_len, plugindir_len = sizeof(plugindir)-1;
189
const char *plugindir = "/conf/conf.d/mandos/plugins.d";
33
192
struct dirent *dirst;
36
195
int ret, maxfd = 0;
37
process *process_list = NULL;
199
int exitstatus = EXIT_SUCCESS;
200
struct sigaction old_sigchld_action;
201
struct sigaction sigchld_action = { .sa_handler = handle_sigchld,
202
.sa_flags = SA_NOCLDSTOP };
203
char *plus_options = NULL;
204
char **plus_argv = NULL;
206
/* Establish a signal handler */
207
sigemptyset(&sigchld_action.sa_mask);
208
ret = sigaddset(&sigchld_action.sa_mask, SIGCHLD);
213
ret = sigaction(SIGCHLD, &sigchld_action, &old_sigchld_action);
219
/* The options we understand. */
220
struct argp_option options[] = {
221
{ .name = "global-options", .key = 'g',
222
.arg = "OPTION[,OPTION[,...]]",
223
.doc = "Options passed to all plugins" },
224
{ .name = "options-for", .key = 'o',
225
.arg = "PLUGIN:OPTION[,OPTION[,...]]",
226
.doc = "Options passed only to specified plugin" },
227
{ .name = "disable", .key = 'd',
229
.doc = "Disable a specific plugin", .group = 1 },
230
{ .name = "plugin-dir", .key = 128,
232
.doc = "Specify a different plugin directory", .group = 2 },
233
{ .name = "userid", .key = 129,
234
.arg = "ID", .flags = 0,
235
.doc = "User ID the plugins will run as", .group = 2 },
236
{ .name = "groupid", .key = 130,
237
.arg = "ID", .flags = 0,
238
.doc = "Group ID the plugins will run as", .group = 2 },
239
{ .name = "debug", .key = 131,
240
.doc = "Debug mode", .group = 3 },
244
error_t parse_opt (int key, char *arg, struct argp_state *state) {
245
/* Get the INPUT argument from `argp_parse', which we know is a
246
pointer to our plugin list pointer. */
247
plugin **plugins = state->input;
251
char *p = strtok(arg, ",");
253
addargument(getplugin(NULL, plugins), p);
254
p = strtok(NULL, ",");
260
char *name = strtok(arg, ":");
261
char *p = strtok(NULL, ":");
265
addargument(getplugin(name, plugins), p);
266
p = strtok(NULL, ",");
273
getplugin(arg, plugins)->disabled = true;
280
uid = (uid_t)strtol(arg, NULL, 10);
283
gid = (gid_t)strtol(arg, NULL, 10);
289
if(plus_options != NULL or arg == NULL or arg[0] != '+'){
297
return ARGP_ERR_UNKNOWN;
302
plugin *plugin_list = NULL;
304
struct argp argp = { .options = options, .parser = parse_opt,
305
.args_doc = "[+PLUS_SEPARATED_OPTIONS]",
306
.doc = "Mandos plugin runner -- Run plugins" };
308
ret = argp_parse (&argp, argc, argv, 0, 0, &plugin_list);
309
if (ret == ARGP_ERR_UNKNOWN){
310
fprintf(stderr, "Unknown error while parsing arguments\n");
311
exitstatus = EXIT_FAILURE;
316
/* This is a mangled argument in the form of
317
"+--option+--other-option=parameter+--yet-another-option", etc */
318
/* Make new argc and argv vars, and call argp_parse() again. */
319
plus_options++; /* skip the first '+' character */
320
const char delims[] = "+";
323
plus_argv = malloc(sizeof(char*) * 2);
324
if(plus_argv == NULL){
326
exitstatus = EXIT_FAILURE;
329
plus_argv[0] = argv[0];
331
arg = strtok(plus_options, delims); /* Get first argument */
334
plus_argv = realloc(plus_argv, sizeof(char *)
335
* ((unsigned int) new_argc + 1));
336
if(plus_argv == NULL){
338
exitstatus = EXIT_FAILURE;
341
plus_argv[new_argc-1] = arg;
342
plus_argv[new_argc] = NULL;
343
arg = strtok(NULL, delims); /* Get next argument */
345
ret = argp_parse (&argp, new_argc, plus_argv, 0, 0, &plugin_list);
346
if (ret == ARGP_ERR_UNKNOWN){
347
fprintf(stderr, "Unknown error while parsing arguments\n");
348
exitstatus = EXIT_FAILURE;
354
for(plugin *p = plugin_list; p != NULL; p=p->next){
355
fprintf(stderr, "Plugin: %s has %d arguments\n",
356
p->name ? p->name : "Global", p->argc - 1);
357
for(char **a = p->argv; *a != NULL; a++){
358
fprintf(stderr, "\tArg: %s\n", *a);
39
373
dir = opendir(plugindir);
42
fprintf(stderr, "Can not open directory\n");
375
perror("Could not open plugin dir");
376
exitstatus = EXIT_FAILURE;
380
/* Set the FD_CLOEXEC flag on the directory, if possible */
382
int dir_fd = dirfd(dir);
384
ret = set_cloexec_flag(dir_fd);
386
perror("set_cloexec_flag");
387
exitstatus = EXIT_FAILURE;
49
396
dirst = readdir(dir);
51
398
// All directory entries have been processed
52
399
if(dirst == NULL){
402
exitstatus = EXIT_FAILURE;
56
408
d_name_len = strlen(dirst->d_name);
58
// Ignore dotfiles and backup files
59
if (dirst->d_name[0] == '.'
60
or dirst->d_name[d_name_len - 1] == '~'){
64
char *filename = malloc(d_name_len + plugindir_len + 2);
65
strcpy(filename, plugindir);
66
strcat(filename, "/");
67
strcat(filename, dirst->d_name);
71
if (S_ISREG(st.st_mode) and (access(filename, X_OK) == 0)){
72
// Starting a new process to be watched
73
process *new_process = malloc(sizeof(process));
76
new_process->pid = fork();
77
if(new_process->pid == 0){
78
/* this is the child process */
410
// Ignore dotfiles, backup files and other junk
412
bool bad_name = false;
414
const char const *bad_prefixes[] = { ".", "#", NULL };
416
const char const *bad_suffixes[] = { "~", "#", ".dpkg-new",
418
".dpkg-divert", NULL };
419
for(const char **pre = bad_prefixes; *pre != NULL; pre++){
420
size_t pre_len = strlen(*pre);
421
if((d_name_len >= pre_len)
422
and strncmp((dirst->d_name), *pre, pre_len) == 0){
424
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
425
" with bad prefix %s\n", dirst->d_name, *pre);
436
for(const char **suf = bad_suffixes; *suf != NULL; suf++){
437
size_t suf_len = strlen(*suf);
438
if((d_name_len >= suf_len)
439
and (strcmp((dirst->d_name)+d_name_len-suf_len, *suf)
442
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
443
" with bad suffix %s\n", dirst->d_name, *suf);
455
char *filename = malloc(d_name_len + strlen(plugindir) + 2);
456
if (filename == NULL){
460
strcpy(filename, plugindir); /* Spurious warning */
461
strcat(filename, "/"); /* Spurious warning */
462
strcat(filename, dirst->d_name); /* Spurious warning */
464
ret = stat(filename, &st);
471
if (not S_ISREG(st.st_mode) or (access(filename, X_OK) != 0)){
473
fprintf(stderr, "Ignoring plugin dir entry \"%s\""
474
" with bad type or mode\n", filename);
479
if(getplugin(dirst->d_name, &plugin_list)->disabled){
481
fprintf(stderr, "Ignoring disabled plugin \"%s\"\n",
487
plugin *p = getplugin(dirst->d_name, &plugin_list);
489
/* Add global arguments to argument list for this plugin */
490
plugin *g = getplugin(NULL, &plugin_list);
491
for(char **a = g->argv + 1; *a != NULL; a++){
499
exitstatus = EXIT_FAILURE;
502
ret = set_cloexec_flag(pipefd[0]);
504
perror("set_cloexec_flag");
505
exitstatus = EXIT_FAILURE;
508
ret = set_cloexec_flag(pipefd[1]);
510
perror("set_cloexec_flag");
511
exitstatus = EXIT_FAILURE;
514
/* Block SIGCHLD until process is safely in process list */
515
ret = sigprocmask (SIG_BLOCK, &sigchld_action.sa_mask, NULL);
517
perror("sigprocmask");
518
exitstatus = EXIT_FAILURE;
521
// Starting a new process to be watched
525
exitstatus = EXIT_FAILURE;
529
/* this is the child process */
530
ret = sigaction(SIGCHLD, &old_sigchld_action, NULL);
535
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
537
perror("sigprocmask");
541
ret = dup2(pipefd[1], STDOUT_FILENO); /* replace our stdout */
548
/* If dir has no file descriptor, we could not set FD_CLOEXEC
549
above and must now close it manually here. */
80
close(pipefd[0]); /* close unused read end of pipe */
81
dup2(pipefd[1], STDOUT_FILENO); /* replace our stdout */
82
/* create a new modified argument list */
83
char **new_argv = malloc(sizeof(char *) * (argc + 1));
84
new_argv[0] = filename;
85
for(int i = 1; i < argc; i++){
86
new_argv[i] = argv[i];
88
new_argv[argc] = NULL;
89
if(execv(filename, new_argv) < 0){
96
close(pipefd[1]); /* close unused write end of pipe */
97
new_process->fd = pipefd[0];
98
new_process->buffer = malloc(BUFFER_SIZE);
99
if (new_process->buffer == NULL){
103
new_process->buffer_size = BUFFER_SIZE;
104
new_process->buffer_length = 0;
105
FD_SET(new_process->fd, &rfds_orig);
107
if (maxfd < new_process->fd){
108
maxfd = new_process->fd;
112
new_process->next = process_list;
113
process_list = new_process;
552
if(execv(filename, p->argv) < 0){
560
close(pipefd[1]); /* close unused write end of pipe */
561
process *new_process = malloc(sizeof(process));
562
if (new_process == NULL){
564
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
566
perror("sigprocmask");
568
exitstatus = EXIT_FAILURE;
572
*new_process = (struct process){ .pid = pid,
574
.next = process_list };
576
process_list = new_process;
577
/* Unblock SIGCHLD so signal handler can be run if this process
578
has already completed */
579
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask, NULL);
581
perror("sigprocmask");
582
exitstatus = EXIT_FAILURE;
586
FD_SET(new_process->fd, &rfds_all);
588
if (maxfd < new_process->fd){
589
maxfd = new_process->fd;
594
/* Free the plugin list */
595
for(plugin *next; plugin_list != NULL; plugin_list = next){
596
next = plugin_list->next;
597
free(plugin_list->argv);
119
if (process_list != NULL){
121
fd_set rfds = rfds_orig;
122
int select_ret = select(maxfd+1, &rfds, NULL, NULL, NULL);
123
if (select_ret == -1){
127
for(process *process_itr = process_list; process_itr != NULL;
128
process_itr = process_itr->next){
129
if(FD_ISSET(process_itr->fd, &rfds)){
130
if(process_itr->buffer_length + BUFFER_SIZE
131
> process_itr->buffer_size){
132
process_itr->buffer = realloc(process_itr->buffer,
133
process_itr->buffer_size
135
if (process_itr->buffer == NULL){
139
process_itr->buffer_size += BUFFER_SIZE;
604
if (process_list == NULL){
605
fprintf(stderr, "No plugin processes started. Incorrect plugin"
610
fd_set rfds = rfds_all;
611
int select_ret = select(maxfd+1, &rfds, NULL, NULL, NULL);
612
if (select_ret == -1){
614
exitstatus = EXIT_FAILURE;
617
/* OK, now either a process completed, or something can be read
619
for(process *proc = process_list; proc ; proc = proc->next){
620
/* Is this process completely done? */
621
if(proc->eof and proc->completed){
622
/* Only accept the plugin output if it exited cleanly */
623
if(not WIFEXITED(proc->status)
624
or WEXITSTATUS(proc->status) != 0){
625
/* Bad exit by plugin */
627
if(WIFEXITED(proc->status)){
628
fprintf(stderr, "Plugin %u exited with status %d\n",
629
(unsigned int) (proc->pid),
630
WEXITSTATUS(proc->status));
631
} else if(WIFSIGNALED(proc->status)) {
632
fprintf(stderr, "Plugin %u killed by signal %d\n",
633
(unsigned int) (proc->pid),
634
WTERMSIG(proc->status));
635
} else if(WCOREDUMP(proc->status)){
636
fprintf(stderr, "Plugin %d dumped core\n",
637
(unsigned int) (proc->pid));
141
ret = read(process_itr->fd, process_itr->buffer
142
+ process_itr->buffer_length, BUFFER_SIZE);
143
process_itr->buffer_length+=ret;
146
/* wait for process exit */
148
waitpid(process_itr->pid, &status, 0);
149
if(WIFEXITED(status) and WEXITSTATUS(status) == 0){
150
write(STDOUT_FILENO, process_itr->buffer,
151
process_itr->buffer_length);
154
FD_CLR(process_itr->fd, &rfds_orig);
640
/* Remove the plugin */
641
FD_CLR(proc->fd, &rfds_all);
642
/* Block signal while modifying process_list */
643
ret = sigprocmask (SIG_BLOCK, &sigchld_action.sa_mask, NULL);
645
perror("sigprocmask");
646
exitstatus = EXIT_FAILURE;
649
/* Delete this process entry from the list */
650
if(process_list == proc){
651
/* First one - simple */
652
process_list = proc->next;
654
/* Second one or later */
655
for(process *p = process_list; p != NULL; p = p->next){
657
p->next = proc->next;
662
/* We are done modifying process list, so unblock signal */
663
ret = sigprocmask (SIG_UNBLOCK, &sigchld_action.sa_mask,
666
perror("sigprocmask");
670
/* We deleted this process from the list, so we can't go
671
proc->next. Therefore, start over from the beginning of
675
/* This process exited nicely, so print its buffer */
677
bool bret = print_out_password(proc->buffer, proc->buffer_length);
679
perror("print_out_password");
680
exitstatus = EXIT_FAILURE;
684
/* This process has not completed. Does it have any output? */
685
if(proc->eof or not FD_ISSET(proc->fd, &rfds)){
686
/* This process had nothing to say at this time */
689
/* Before reading, make the process' data buffer large enough */
690
if(proc->buffer_length + BUFFER_SIZE > proc->buffer_size){
691
proc->buffer = realloc(proc->buffer, proc->buffer_size
692
+ (size_t) BUFFER_SIZE);
693
if (proc->buffer == NULL){
695
exitstatus = EXIT_FAILURE;
698
proc->buffer_size += BUFFER_SIZE;
700
/* Read from the process */
701
ret = read(proc->fd, proc->buffer + proc->buffer_length,
704
/* Read error from this process; ignore the error */
711
proc->buffer_length += (size_t) ret;
164
for(process *process_itr = process_list; process_itr != NULL;
165
process_itr = process_itr->next){
166
close(process_itr->fd);
167
kill(process_itr->pid, SIGTERM);
168
free(process_itr->buffer);
719
if(process_list == NULL or exitstatus != EXIT_SUCCESS){
720
/* Fallback if all plugins failed, none are found or an error occured */
722
fprintf(stderr, "Going to fallback mode using getpass(3)\n");
723
char *passwordbuffer = getpass("Password: ");
724
bret = print_out_password(passwordbuffer, strlen(passwordbuffer));
726
perror("print_out_password");
727
exitstatus = EXIT_FAILURE;
732
/* Restore old signal handler */
733
sigaction(SIGCHLD, &old_sigchld_action, NULL);
737
/* Free the plugin list */
738
for(plugin *next; plugin_list != NULL; plugin_list = next){
739
next = plugin_list->next;
740
free(plugin_list->argv);
748
/* Free the process list and kill the processes */
749
for(process *next; process_list != NULL; process_list = next){
750
next = process_list->next;
751
close(process_list->fd);
752
ret = kill(process_list->pid, SIGTERM);
753
if(ret == -1 and errno != ESRCH){
754
/* set-uid proccesses migth not get closed */
757
free(process_list->buffer);
761
/* Wait for any remaining child processes to terminate */