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/cvs/rxvt-unicode/src/rxvtd.C
Revision: 1.63
Committed: Sun May 9 05:53:12 2021 UTC (3 years ago) by sf-exg
Content type: text/plain
Branch: MAIN
CVS Tags: rxvt-unicode-rel-9_26, rxvt-unicode-rel-9_25
Changes since 1.62: +83 -15 lines
Log Message:
Add support for systemd socket activation

File Contents

# Content
1 /*----------------------------------------------------------------------*
2 * File: rxvtd.C
3 *----------------------------------------------------------------------*
4 *
5 * All portions of code are copyright by their respective author/s.
6 * Copyright (c) 2003-2007 Marc Lehmann <schmorp@schmorp.de>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 3 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21 *----------------------------------------------------------------------*/
22
23 #include "../config.h"
24 #include <stdio.h>
25 #include <stdlib.h>
26 #include <stdarg.h>
27 #include <string.h>
28
29 #include <unistd.h>
30 #include <fcntl.h>
31 #include <sys/types.h>
32 #include <sys/stat.h>
33 #include <sys/socket.h>
34 #include <sys/un.h>
35
36 #if defined(ENABLE_FRILLS) && defined(_POSIX_MEMLOCK) && _POSIX_MEMLOCK > 0
37 # define ENABLE_MLOCK 1
38 #endif
39
40 #if ENABLE_MLOCK
41 # include <sys/mman.h>
42 #endif
43
44 #include <errno.h>
45
46 #include "rxvt.h"
47 #include "rxvtdaemon.h"
48 #include "libptytty.h"
49
50 struct server : rxvt_connection {
51 log_callback log_cb;
52 getfd_callback getfd_cb;
53
54 void read_cb (ev::io &w, int revents); ev::io read_ev;
55 void log_msg (const char *msg);
56 int getfd (int remote_fd);
57
58 server (int fd)
59 {
60 read_ev.set <server, &server::read_cb> (this);
61 log_cb.set <server, &server::log_msg> (this);
62 getfd_cb.set<server, &server::getfd> (this);
63
64 this->fd = fd;
65 fcntl (fd, F_SETFD, FD_CLOEXEC);
66 fcntl (fd, F_SETFL, 0);
67 read_ev.start (fd, ev::READ);
68 }
69
70 void err (const char *format = 0, ...);
71 };
72
73 struct unix_listener {
74 int fd;
75
76 void accept_cb (ev::io &w, int revents); ev::io accept_ev;
77
78 unix_listener (int fd);
79 static int open (const char *sockname);
80 };
81
82 unix_listener::unix_listener (int fd) : fd (fd)
83 {
84 accept_ev.set<unix_listener, &unix_listener::accept_cb> (this);
85 fcntl (fd, F_SETFD, FD_CLOEXEC);
86 fcntl (fd, F_SETFL, O_NONBLOCK);
87 accept_ev.start (fd, ev::READ);
88 }
89
90 int unix_listener::open (const char *sockname)
91 {
92 sockaddr_un sa;
93
94 if (strlen (sockname) >= sizeof(sa.sun_path))
95 {
96 fputs ("socket name too long, aborting.\n", stderr);
97 exit (EXIT_FAILURE);
98 }
99
100 int fd;
101 if ((fd = socket (AF_UNIX, SOCK_STREAM, 0)) < 0)
102 {
103 perror ("unable to create listening socket");
104 exit (EXIT_FAILURE);
105 }
106
107 sa.sun_family = AF_UNIX;
108 strcpy (sa.sun_path, sockname);
109
110 unlink (sockname);
111
112 mode_t omask = umask (0077);
113
114 if (bind (fd, (sockaddr *)&sa, sizeof (sa)))
115 {
116 perror ("unable to bind listening socket");
117 exit (EXIT_FAILURE);
118 }
119
120 umask (omask);
121
122 if (listen (fd, 5))
123 {
124 perror ("unable to listen on socket");
125 exit (EXIT_FAILURE);
126 }
127
128 return fd;
129 }
130
131 void unix_listener::accept_cb (ev::io &w, int revents)
132 {
133 int fd2 = accept (fd, 0, 0);
134
135 if (fd2 >= 0)
136 new server (fd2);
137 }
138
139 int server::getfd (int remote_fd)
140 {
141 send ("GETFD");
142 send (remote_fd);
143 return ptytty::recv_fd (fd);
144 }
145
146 void server::log_msg (const char *msg)
147 {
148 send ("MSG"), send (msg);
149 }
150
151 void server::err (const char *format, ...)
152 {
153 if (format)
154 {
155 char err[1024];
156
157 va_list ap;
158 va_start (ap, format);
159 vsnprintf (err, 1024, format, ap);
160 va_end (ap);
161
162 log_msg (err);
163 }
164
165 send ("END"), send (0);
166 close (fd);
167 delete this;
168 }
169
170 void server::read_cb (ev::io &w, int revents)
171 {
172 auto_str tok;
173
174 if (recv (tok))
175 {
176 if (!strcmp (tok, "NEW"))
177 {
178 stringvec *argv = new stringvec;
179 stringvec *envv = new stringvec;
180
181 for (;;)
182 {
183 if (!recv (tok))
184 return err ();
185
186 if (!strcmp (tok, "END"))
187 break;
188 else if (!strcmp (tok, "ENV") && recv (tok))
189 envv->push_back (strdup (tok));
190 else if (!strcmp (tok, "ARG") && recv (tok))
191 argv->push_back (strdup (tok));
192 else
193 return err ("protocol error: unexpected NEW token.\n");
194 }
195
196 {
197 rxvt_term *term = new rxvt_term;
198
199 term->log_hook = &log_cb;
200 term->getfd_hook = &getfd_cb;
201
202 bool success = true;
203
204 try
205 {
206 term->init (argv, envv);
207 }
208 catch (const class rxvt_failure_exception &e)
209 {
210 success = false;
211 }
212
213 term->log_hook = 0;
214
215 chdir ("/"); // init might change to different working directory
216
217 if (!success)
218 term->destroy ();
219
220 send ("END"); send (success ? 1 : 0);
221 }
222 }
223 else if (!strcmp (tok, "QUIT"))
224 _exit (0);
225 else
226 return err ("protocol error: request '%s' unsupported.\n", (char *)tok);
227 }
228 else
229 return err ();
230 }
231
232 #ifdef ENABLE_FRILLS
233 enum {
234 SD_LISTEN_FDS_START = 3,
235 };
236
237 // https://www.freedesktop.org/software/systemd/man/sd_listen_fds.html
238 // https://github.com/systemd/systemd/blob/main/src/libsystemd/sd-daemon/sd-daemon.c
239 static int get_listen_fds ()
240 {
241 const char *listen_pid = getenv ("LISTEN_PID");
242 if (!listen_pid)
243 return 0;
244
245 char *end;
246 errno = 0;
247 long pid = strtol (listen_pid, &end, 10);
248 if (errno || end == listen_pid || *end)
249 return -1;
250
251 if (getpid () != pid)
252 return 0;
253
254 const char *listen_fds = getenv ("LISTEN_FDS");
255 if (!listen_fds)
256 return 0;
257
258 errno = 0;
259 long n = strtol (listen_fds, &end, 10);
260 if (errno || end == listen_fds || *end)
261 return -1;
262
263 if (n <= 0 || n > INT_MAX - SD_LISTEN_FDS_START)
264 return -1;
265
266 unsetenv ("LISTEN_PID");
267 unsetenv ("LISTEN_FDS");
268 unsetenv ("LISTEN_FDNAMES");
269
270 return n;
271 }
272 #endif
273
274 int
275 main (int argc, char *argv[])
276 {
277 ptytty::init ();
278
279 static char opt_fork, opt_opendisplay, opt_quiet;
280 #if ENABLE_PERL
281 static char *opt_eval;
282 #endif
283 #if ENABLE_MLOCK
284 static char opt_lock;
285 #endif
286
287 for (int i = 1; i < argc; i++)
288 {
289 if (!strcmp (argv [i], "-f") || !strcmp (argv [i], "--fork"))
290 opt_fork = 1;
291 else if (!strcmp (argv [i], "-o") || !strcmp (argv [i], "--opendisplay"))
292 opt_opendisplay = 1;
293 else if (!strcmp (argv [i], "-q") || !strcmp (argv [i], "--quiet"))
294 opt_quiet = 1;
295 #if ENABLE_MLOCK
296 else if (!strcmp (argv [i], "-m") || !strcmp (argv [i], "--mlock"))
297 opt_lock = 1;
298 #endif
299 #if ENABLE_PERL
300 else if (!strcmp (argv [i], "-e") || !strcmp (argv [i], "--eval"))
301 opt_eval = argv [++i];
302 #endif
303 else
304 {
305 rxvt_log ("%s: unknown option '%s', aborting.\n", argv [0], argv [i]);
306 return EXIT_FAILURE;
307 }
308 }
309
310 rxvt_init ();
311
312 #if ENABLE_PERL
313 if (opt_eval)
314 {
315 rxvt_perl.init ();
316 rxvt_perl.eval (opt_eval);
317 }
318 #endif
319
320 // optionally open display and never release it.
321 if (opt_opendisplay)
322 if (const char *dpy = getenv ("DISPLAY"))
323 displays.get (dpy ? dpy : ":0"); // move string logic into rxvt_display maybe?
324
325 int fd;
326 #ifdef ENABLE_FRILLS
327 int n = get_listen_fds ();
328 if (n > 1)
329 {
330 fputs ("received multiple file descriptors, aborting.\n", stderr);
331 exit (EXIT_FAILURE);
332 }
333 else if (n == 1)
334 {
335 fd = SD_LISTEN_FDS_START;
336 if (!opt_quiet)
337 {
338 printf ("rxvt-unicode daemon listening on fd.\n");
339 fflush (stdout);
340 }
341 }
342 else
343 #endif
344 {
345 char *sockname = rxvt_connection::unix_sockname ();
346 fd = unix_listener::open (sockname);
347 if (!opt_quiet)
348 {
349 printf ("rxvt-unicode daemon listening on %s.\n", sockname);
350 fflush (stdout);
351 }
352 free (sockname);
353 }
354
355 unix_listener l (fd);
356
357 chdir ("/");
358
359 pid_t pid = 0;
360 if (opt_fork)
361 {
362 pid = fork ();
363 }
364
365 #if ENABLE_MLOCK
366 // Optionally perform an mlockall so this process does not get swapped out.
367 if (opt_lock && !pid)
368 if (mlockall (MCL_CURRENT | MCL_FUTURE) < 0)
369 perror ("unable to lock into ram");
370 #endif
371
372 if (opt_fork)
373 {
374 if (pid < 0)
375 {
376 rxvt_log ("unable to fork daemon, aborting.\n");
377 return EXIT_FAILURE;
378 }
379 else if (pid > 0)
380 _exit (EXIT_SUCCESS);
381
382 ev_loop_fork (EV_DEFAULT_UC);
383 }
384
385 ev_run ();
386
387 return EXIT_SUCCESS;
388 }
389