1
/* -*- coding: utf-8 -*- */
3
* Passprompt - Read a password from splashy and output it
5
* Copyright © 2008 Teddy Hogeborn
6
* Copyright © 2008 Björn Påhlsson
8
* This program is free software: you can redistribute it and/or
9
* modify it under the terms of the GNU General Public License as
10
* published by the Free Software Foundation, either version 3 of the
11
* License, or (at your option) any later version.
13
* This program is distributed in the hope that it will be useful, but
14
* WITHOUT ANY WARRANTY; without even the implied warranty of
15
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16
* General Public License for more details.
18
* You should have received a copy of the GNU General Public License
19
* along with this program. If not, see
20
* <http://www.gnu.org/licenses/>.
22
* Contact the authors at <https://www.fukt.bsnet.se/~belorn/> and
23
* <https://www.fukt.bsnet.se/~teddy/>.
26
#define _GNU_SOURCE /* asprintf() */
27
#include <signal.h> /* sig_atomic_t, struct sigaction,
28
sigemptyset(), sigaddset(), SIGINT,
29
SIGHUP, SIGTERM, sigaction,
30
SIG_IGN, kill(), SIGKILL */
31
#include <stddef.h> /* NULL */
32
#include <stdlib.h> /* getenv() */
33
#include <stdio.h> /* asprintf(), perror() */
34
#include <stdlib.h> /* EXIT_FAILURE, free(), strtoul(),
36
#include <sys/types.h> /* pid_t, DIR, struct dirent,
38
#include <dirent.h> /* opendir(), readdir(), closedir() */
39
#include <sys/stat.h> /* struct stat, lstat(), S_ISLNK */
40
#include <iso646.h> /* not, or, and */
41
#include <unistd.h> /* readlink(), fork(), execl(),
42
sleep(), dup2() STDERR_FILENO,
43
STDOUT_FILENO, _exit() */
44
#include <string.h> /* memcmp() */
45
#include <errno.h> /* errno */
46
#include <sys/wait.h> /* waitpid(), WIFEXITED(),
49
sig_atomic_t interrupted_by_signal = 0;
51
static void termination_handler(__attribute__((unused))int signum){
52
interrupted_by_signal = 1;
55
int main(__attribute__((unused))int argc,
56
__attribute__((unused))char **argv){
59
/* Create prompt string */
62
const char *const cryptsource = getenv("cryptsource");
63
const char *const crypttarget = getenv("crypttarget");
64
const char *const prompt_start = "getpass "
65
"Enter passphrase to unlock the disk";
67
if(cryptsource == NULL){
68
if(crypttarget == NULL){
69
ret = asprintf(&prompt, "%s: ", prompt_start);
71
ret = asprintf(&prompt, "%s (%s): ", prompt_start,
75
if(crypttarget == NULL){
76
ret = asprintf(&prompt, "%s %s: ", prompt_start, cryptsource);
78
ret = asprintf(&prompt, "%s %s (%s): ", prompt_start,
79
cryptsource, crypttarget);
87
/* Find splashy process */
88
pid_t splashy_pid = 0;
90
const char splashy_name[] = "/sbin/splashy";
91
DIR *proc_dir = opendir("/proc");
97
for(struct dirent *proc_ent = readdir(proc_dir);
99
proc_ent = readdir(proc_dir)){
100
pid_t pid = (pid_t) strtoul(proc_ent->d_name, NULL, 10);
105
/* Find the executable name by doing readlink() on the
106
/proc/<pid>/exe link */
107
char exe_target[sizeof(splashy_name)];
111
ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
119
/* Check that it refers to a symlink owned by root:root */
120
struct stat exe_stat;
121
ret = lstat(exe_link, &exe_stat);
129
if(not S_ISLNK(exe_stat.st_mode)
130
or exe_stat.st_uid != 0
131
or exe_stat.st_gid != 0){
136
sret = readlink(exe_link, exe_target, sizeof(exe_target));
139
if((sret == ((ssize_t)sizeof(exe_target)-1))
140
and (memcmp(splashy_name, exe_target,
141
sizeof(exe_target)-1) == 0)){
148
if(splashy_pid == 0){
153
/* Set up the signal handler */
155
struct sigaction old_action,
156
new_action = { .sa_handler = termination_handler,
158
sigemptyset(&new_action.sa_mask);
159
sigaddset(&new_action.sa_mask, SIGINT);
160
sigaddset(&new_action.sa_mask, SIGHUP);
161
sigaddset(&new_action.sa_mask, SIGTERM);
162
ret = sigaction(SIGINT, NULL, &old_action);
168
if(old_action.sa_handler != SIG_IGN){
169
ret = sigaction(SIGINT, &new_action, NULL);
176
ret = sigaction(SIGHUP, NULL, &old_action);
182
if(old_action.sa_handler != SIG_IGN){
183
ret = sigaction(SIGHUP, &new_action, NULL);
190
ret = sigaction(SIGTERM, NULL, &old_action);
196
if(old_action.sa_handler != SIG_IGN){
197
ret = sigaction(SIGTERM, &new_action, NULL);
206
/* Fork off the splashy command to prompt for password */
207
pid_t splashy_command_pid = 0;
208
if(not interrupted_by_signal){
209
splashy_command_pid = fork();
210
if(splashy_command_pid == -1){
211
if(not interrupted_by_signal){
217
if(splashy_command_pid == 0){
218
const char splashy_command[] = "/sbin/splashy_update";
219
ret = execl(splashy_command, splashy_command, prompt,
221
if(not interrupted_by_signal){
232
/* Wait for command to complete */
233
if(not interrupted_by_signal and splashy_command_pid != 0){
235
ret = waitpid(splashy_command_pid, &status, 0);
241
splashy_command_pid = 0;
244
/* The child process has exited */
245
splashy_command_pid = 0;
246
if(not interrupted_by_signal and WIFEXITED(status)
247
and WEXITSTATUS(status)==0){
252
kill(splashy_pid, SIGTERM);
253
if(interrupted_by_signal and splashy_command_pid != 0){
254
kill(splashy_command_pid, SIGTERM);
257
while(kill(splashy_pid, 0) == 0){
258
kill(splashy_pid, SIGKILL);
261
pid_t new_splashy_pid = fork();
262
if(new_splashy_pid == 0){
263
/* Child; will become new splashy process */
265
/* Make the effective user ID (root) the only user ID instead of
266
the real user ID (mandos) */
267
ret = setuid(geteuid());
274
/* if(fork() != 0){ */
275
/* _exit(EXIT_SUCCESS); */
277
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
283
execl("/sbin/splashy", "/sbin/splashy", "boot", (char *)NULL);
284
if(not interrupted_by_signal){
added
removed
plugins.d/splashy.c
