1 /*
2  *   stunnel       TLS offloading and load-balancing proxy
3  *   Copyright (C) 1998-2021 Michal Trojnara <Michal.Trojnara@stunnel.org>
4  *
5  *   This program is free software; you can redistribute it and/or modify it
6  *   under the terms of the GNU General Public License as published by the
7  *   Free Software Foundation; either version 2 of the License, or (at your
8  *   option) any later version.
9  *
10  *   This program is distributed in the hope that it will be useful,
11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
13  *   See the GNU General Public License for more details.
14  *
15  *   You should have received a copy of the GNU General Public License along
16  *   with this program; if not, see <http://www.gnu.org/licenses>.
17  *
18  *   Linking stunnel statically or dynamically with other modules is making
19  *   a combined work based on stunnel. Thus, the terms and conditions of
20  *   the GNU General Public License cover the whole combination.
21  *
22  *   In addition, as a special exception, the copyright holder of stunnel
23  *   gives you permission to combine stunnel with free software programs or
24  *   libraries that are released under the GNU LGPL and with code included
25  *   in the standard release of OpenSSL under the OpenSSL License (or
26  *   modified versions of such code, with unchanged license). You may copy
27  *   and distribute such a system following the terms of the GNU GPL for
28  *   stunnel and the licenses of the other code concerned.
29  *
30  *   Note that people who make modified versions of stunnel are not obligated
31  *   to grant this special exception for their modified versions; it is their
32  *   choice whether to do so. The GNU General Public License gives permission
33  *   to release a modified version without this exception; this exception
34  *   also makes it possible to release a modified version which carries
35  *   forward this exception.
36  */
37 
38 #include "common.h"
39 #include "prototypes.h"
40 
41 NOEXPORT int main_unix(int, char*[]);
42 #if !defined(__vms) && !defined(USE_OS2)
43 NOEXPORT int daemonize(int);
44 NOEXPORT int create_pid(void);
45 NOEXPORT void delete_pid(void);
46 #endif
47 #ifndef USE_OS2
48 NOEXPORT void signal_handler(int);
49 #endif
50 
main(int argc,char * argv[])51 int main(int argc, char* argv[]) { /* execution begins here 8-) */
52     int retval;
53 
54 #ifdef M_MMAP_THRESHOLD
55     mallopt(M_MMAP_THRESHOLD, 4096);
56 #endif
57     tls_init(); /* initialize thread-local storage */
58     retval=main_unix(argc, argv);
59     main_cleanup();
60     return retval;
61 }
62 
main_unix(int argc,char * argv[])63 NOEXPORT int main_unix(int argc, char* argv[]) {
64     int configure_status;
65 
66 #if !defined(__vms) && !defined(USE_OS2)
67     int fd;
68 
69     fd=open("/dev/null", O_RDWR); /* open /dev/null before chroot */
70     if(fd==INVALID_SOCKET)
71         fatal("Could not open /dev/null");
72 #endif
73     main_init();
74     configure_status=main_configure(argc>1 ? argv[1] : NULL,
75         argc>2 ? argv[2] : NULL);
76     switch(configure_status) {
77     case 1: /* error -> exit with 1 to indicate error */
78         close(fd);
79         return 1;
80     case 2: /* information printed -> exit with 0 to indicate success */
81         close(fd);
82         return 0;
83     }
84     if(service_options.next) { /* there are service sections -> daemon mode */
85 #if !defined(__vms) && !defined(USE_OS2)
86         if(daemonize(fd)) {
87             close(fd);
88             return 1;
89         }
90         close(fd);
91         /* create_pid() must be called after drop_privileges()
92          * or it won't be possible to remove the file on exit */
93         /* create_pid() must be called after daemonize()
94          * since the final pid is not known beforehand */
95         if(create_pid())
96             return 1;
97 #endif
98 #ifndef USE_OS2
99         signal(SIGCHLD, signal_handler); /* handle dead children */
100         signal(SIGHUP, signal_handler); /* configuration reload */
101         signal(SIGUSR1, signal_handler); /* log reopen */
102         signal(SIGUSR2, signal_handler); /* connections */
103         signal(SIGPIPE, SIG_IGN); /* ignore broken pipe */
104         if(signal(SIGTERM, SIG_IGN)!=SIG_IGN)
105             signal(SIGTERM, signal_handler); /* fatal */
106         if(signal(SIGQUIT, SIG_IGN)!=SIG_IGN)
107             signal(SIGQUIT, signal_handler); /* fatal */
108         if(signal(SIGINT, SIG_IGN)!=SIG_IGN)
109             signal(SIGINT, signal_handler); /* fatal */
110 #endif
111 #ifdef USE_FORK
112         setpgid(0, 0); /* create a new process group if needed */
113 #endif
114         daemon_loop();
115 #ifdef USE_FORK
116         s_log(LOG_NOTICE, "Terminating service processes");
117         signal(SIGCHLD, SIG_IGN);
118         signal(SIGTERM, SIG_IGN);
119         kill(0, SIGTERM); /* kill the whole process group */
120         while(wait(NULL)!=-1)
121             ;
122         s_log(LOG_NOTICE, "Service processes terminated");
123 #endif
124 #if !defined(__vms) && !defined(USE_OS2)
125         delete_pid();
126 #endif /* standard Unix */
127     } else { /* inetd mode */
128         CLI *c;
129 #if !defined(__vms) && !defined(USE_OS2)
130         close(fd);
131 #endif /* standard Unix */
132 #ifndef USE_OS2
133         signal(SIGCHLD, SIG_IGN); /* ignore dead children */
134         signal(SIGPIPE, SIG_IGN); /* ignore broken pipe */
135 #endif
136         set_nonblock(0, 1); /* stdin */
137         set_nonblock(1, 1); /* stdout */
138         c=alloc_client_session(&service_options, 0, 1);
139         tls_alloc(c, ui_tls, NULL);
140         service_up_ref(&service_options);
141         client_main(c);
142         client_free(c);
143     }
144     return 0;
145 }
146 
147 #ifndef USE_OS2
signal_handler(int sig)148 NOEXPORT void signal_handler(int sig) {
149     int saved_errno;
150 
151     saved_errno=errno;
152     signal_post((uint8_t)sig);
153     signal(sig, signal_handler);
154     errno=saved_errno;
155 }
156 #endif
157 
158 #if !defined(__vms) && !defined(USE_OS2)
159 
daemonize(int fd)160 NOEXPORT int daemonize(int fd) { /* go to background */
161     if(global_options.option.foreground)
162         return 0;
163     dup2(fd, 0);
164     dup2(fd, 1);
165     dup2(fd, 2);
166 #if defined(HAVE_DAEMON) && !defined(__BEOS__)
167     /* set noclose option when calling daemon() function,
168      * so it does not require /dev/null device in the chrooted directory */
169     if(daemon(0, 1)==-1) {
170         ioerror("daemon");
171         return 1;
172     }
173 #else
174     chdir("/");
175     switch(fork()) {
176     case -1:    /* fork failed */
177         ioerror("fork");
178         return 1;
179     case 0:     /* child */
180         break;
181     default:    /* parent */
182         exit(0);
183     }
184 #endif
185     tls_alloc(NULL, ui_tls, "main"); /* reuse thread-local storage */
186 #ifdef HAVE_SETSID
187     setsid(); /* ignore the error */
188 #endif
189     return 0;
190 }
191 
create_pid(void)192 NOEXPORT int create_pid(void) {
193     int pf;
194     char *pid;
195 
196     if(!global_options.pidfile) {
197         s_log(LOG_DEBUG, "No pid file being created");
198         return 0;
199     }
200 
201     /* silently remove the old pid file */
202     unlink(global_options.pidfile);
203 
204     /* create a new pid file */
205     pf=open(global_options.pidfile, O_WRONLY|O_CREAT|O_TRUNC|O_EXCL, 0644);
206     if(pf==-1) {
207         s_log(LOG_ERR, "Cannot create pid file %s", global_options.pidfile);
208         ioerror("create");
209         return 1;
210     }
211     pid=str_printf("%lu\n", (unsigned long)getpid());
212     if(write(pf, pid, strlen(pid))<(int)strlen(pid)) {
213         s_log(LOG_ERR, "Cannot write pid file %s", global_options.pidfile);
214         ioerror("write");
215         return 1;
216     }
217     str_free(pid);
218     close(pf);
219     s_log(LOG_DEBUG, "Created pid file %s", global_options.pidfile);
220     return 0;
221 }
222 
delete_pid(void)223 NOEXPORT void delete_pid(void) {
224     if(global_options.pidfile) {
225         if(unlink(global_options.pidfile)<0)
226             ioerror(global_options.pidfile); /* not critical */
227         else
228             s_log(LOG_DEBUG, "Removed pid file %s", global_options.pidfile);
229     } else {
230         s_log(LOG_DEBUG, "No pid file to remove");
231     }
232 }
233 
234 #endif /* standard Unix */
235 
236 /**************************************** options callbacks */
237 
ui_config_reloaded(void)238 void ui_config_reloaded(void) {
239     /* no action */
240 }
241 
242 #ifdef ICON_IMAGE
243 
load_icon_default(ICON_TYPE icon)244 ICON_IMAGE load_icon_default(ICON_TYPE icon) {
245     (void)icon; /* squash the unused parameter warning */
246     return (ICON_IMAGE)0;
247 }
248 
load_icon_file(const char * file)249 ICON_IMAGE load_icon_file(const char *file) {
250     (void)file; /* squash the unused parameter warning */
251     return (ICON_IMAGE)0;
252 }
253 
254 #endif
255 
256 /**************************************** client callbacks */
257 
ui_new_chain(const unsigned section_number)258 void ui_new_chain(const unsigned section_number) {
259     (void)section_number; /* squash the unused parameter warning */
260 }
261 
ui_clients(const long num)262 void ui_clients(const long num) {
263     (void)num; /* squash the unused parameter warning */
264 }
265 
266 /**************************************** s_log callbacks */
267 
ui_new_log(const char * line)268 void ui_new_log(const char *line) {
269     fprintf(stderr, "%s\n", line);
270 }
271 
272 /**************************************** ctx callbacks */
273 
ui_passwd_cb(char * buf,int size,int rwflag,void * userdata)274 int ui_passwd_cb(char *buf, int size, int rwflag, void *userdata) {
275     return PEM_def_callback(buf, size, rwflag, userdata);
276 }
277 
278 #ifndef OPENSSL_NO_ENGINE
279 
ui_get_opener()280 int (*ui_get_opener()) (UI *) {
281     return UI_method_get_opener(UI_OpenSSL());
282 }
283 
ui_get_writer()284 int (*ui_get_writer()) (UI *, UI_STRING *) {
285     return UI_method_get_writer(UI_OpenSSL());
286 }
287 
ui_get_reader()288 int (*ui_get_reader()) (UI *, UI_STRING *) {
289     return UI_method_get_reader(UI_OpenSSL());
290 }
291 
ui_get_closer()292 int (*ui_get_closer()) (UI *) {
293     return UI_method_get_closer(UI_OpenSSL());
294 }
295 
296 #endif
297 
298 /* end of ui_unix.c */
299