rxvt-unicode/src/rxvtd.C

/*----------------------------------------------------------------------*
 * File:        rxvtd.C
 *----------------------------------------------------------------------*
 *
 * All portions of code are copyright by their respective author/s.
 * Copyright (c) 2003-2007 Marc Lehmann <schmorp@schmorp.de>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *----------------------------------------------------------------------*/

#include "../config.h"
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>

#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/un.h>

#if defined(ENABLE_FRILLS) && defined(_POSIX_MEMLOCK) && _POSIX_MEMLOCK > 0
# define ENABLE_MLOCK 1
#endif

#if ENABLE_MLOCK
# include <sys/mman.h>
#endif

#include <errno.h>

#include "rxvt.h"
#include "rxvtdaemon.h"
#include "libptytty.h"

struct server : rxvt_connection {
  log_callback log_cb;
  getfd_callback getfd_cb;

  void read_cb (ev::io &w, int revents); ev::io read_ev;
  void log_msg (const char *msg);
  int getfd (int remote_fd);

  server (int fd)
  {
    read_ev.set <server, &server::read_cb> (this);
    log_cb.set  <server, &server::log_msg> (this);
    getfd_cb.set<server, &server::getfd>   (this);

    this->fd = fd;
    fcntl (fd, F_SETFD, FD_CLOEXEC);
    fcntl (fd, F_SETFL, 0);
    read_ev.start (fd, ev::READ);
  }

  void err (const char *format = 0, ...);
};

struct unix_listener {
  int fd;

  void accept_cb (ev::io &w, int revents); ev::io accept_ev;

  unix_listener (int fd);
  static int open (const char *sockname);
};

unix_listener::unix_listener (int fd) : fd (fd)
{
  accept_ev.set<unix_listener, &unix_listener::accept_cb> (this);
  fcntl (fd, F_SETFD, FD_CLOEXEC);
  fcntl (fd, F_SETFL, O_NONBLOCK);
  accept_ev.start (fd, ev::READ);
}

int unix_listener::open (const char *sockname)
{
  sockaddr_un sa;

  if (strlen (sockname) >= sizeof(sa.sun_path))
    {
      fputs ("socket name too long, aborting.\n", stderr);
      exit (EXIT_FAILURE);
    }

  int fd;
  if ((fd = socket (AF_UNIX, SOCK_STREAM, 0)) < 0)
    {
      perror ("unable to create listening socket");
      exit (EXIT_FAILURE);
    }

  sa.sun_family = AF_UNIX;
  strcpy (sa.sun_path, sockname);

  unlink (sockname);

  mode_t omask = umask (0077);

  if (bind (fd, (sockaddr *)&sa, sizeof (sa)))
    {
      perror ("unable to bind listening socket");
      exit (EXIT_FAILURE);
    }

  umask (omask);

  if (listen (fd, 5))
    {
      perror ("unable to listen on socket");
      exit (EXIT_FAILURE);
    }

  return fd;
}

void unix_listener::accept_cb (ev::io &w, int revents)
{
  int fd2 = accept (fd, 0, 0);

  if (fd2 >= 0)
    new server (fd2);
}

int server::getfd (int remote_fd)
{
  send ("GETFD");
  send (remote_fd);
  return ptytty::recv_fd (fd);
}

void server::log_msg (const char *msg)
{
  send ("MSG"), send (msg);
}

void server::err (const char *format, ...)
{
  if (format)
    {
      char err[1024];

      va_list ap;
      va_start (ap, format);
      vsnprintf (err, 1024, format, ap);
      va_end (ap);

      log_msg (err);
    }

  send ("END"), send (0);
  close (fd);
  delete this;
}

void server::read_cb (ev::io &w, int revents)
{
  auto_str tok;

  if (recv (tok))
    {
      if (!strcmp (tok, "NEW"))
        {
          stringvec *argv = new stringvec;
          stringvec *envv = new stringvec;

          for (;;)
            {
              if (!recv (tok))
                return err ();

              if (!strcmp (tok, "END"))
                break;
              else if (!strcmp (tok, "ENV") && recv (tok))
                envv->push_back (strdup (tok));
              else if (!strcmp (tok, "ARG") && recv (tok))
                argv->push_back (strdup (tok));
              else
                return err ("protocol error: unexpected NEW token.\n");
            }

          {
            rxvt_term *term = new rxvt_term;

            term->log_hook = &log_cb;
            term->getfd_hook = &getfd_cb;

            bool success = true;

            try
              {
                term->init (argv, envv);
              }
            catch (const class rxvt_failure_exception &e)
              {
                success = false;
              }

            term->log_hook = 0;

            chdir ("/"); // init might change to different working directory

            if (!success)
              term->destroy ();

            send ("END"); send (success ? 1 : 0);
          }
        }
      else if (!strcmp (tok, "QUIT"))
        _exit (0);
      else
        return err ("protocol error: request '%s' unsupported.\n", (char *)tok);
    }
  else
    return err ();
}

#ifdef ENABLE_FRILLS
enum {
  SD_LISTEN_FDS_START = 3,
};

// https://www.freedesktop.org/software/systemd/man/sd_listen_fds.html
// https://github.com/systemd/systemd/blob/main/src/libsystemd/sd-daemon/sd-daemon.c
static int get_listen_fds ()
{
  const char *listen_pid = getenv ("LISTEN_PID");
  if (!listen_pid)
    return 0;

  char *end;
  errno = 0;
  long pid = strtol (listen_pid, &end, 10);
  if (errno || end == listen_pid || *end)
    return -1;

  if (getpid () != pid)
    return 0;

  const char *listen_fds = getenv ("LISTEN_FDS");
  if (!listen_fds)
    return 0;

  errno = 0;
  long n = strtol (listen_fds, &end, 10);
  if (errno || end == listen_fds || *end)
    return -1;

  if (n <= 0 || n > INT_MAX - SD_LISTEN_FDS_START)
    return -1;

  unsetenv ("LISTEN_PID");
  unsetenv ("LISTEN_FDS");
  unsetenv ("LISTEN_FDNAMES");

  return n;
}
#endif

int
main (int argc, char *argv[])
{
  ptytty::init ();

  static char opt_fork, opt_opendisplay, opt_quiet;
#if ENABLE_PERL
  static char *opt_eval;
#endif
#if ENABLE_MLOCK
  static char opt_lock;
#endif

  for (int i = 1; i < argc; i++)
    {
      if (!strcmp (argv [i], "-f") || !strcmp (argv [i], "--fork"))
        opt_fork = 1;
      else if (!strcmp (argv [i], "-o") || !strcmp (argv [i], "--opendisplay"))
        opt_opendisplay = 1;
      else if (!strcmp (argv [i], "-q") || !strcmp (argv [i], "--quiet"))
        opt_quiet = 1;
#if ENABLE_MLOCK
      else if (!strcmp (argv [i], "-m") || !strcmp (argv [i], "--mlock"))
        opt_lock = 1;
#endif
#if ENABLE_PERL
      else if (!strcmp (argv [i], "-e") || !strcmp (argv [i], "--eval"))
        opt_eval = argv [++i];
#endif
      else
        {
          rxvt_log ("%s: unknown option '%s', aborting.\n", argv [0], argv [i]);
          return EXIT_FAILURE;
        }
    }

  rxvt_init ();

#if ENABLE_PERL
  if (opt_eval)
    {
      rxvt_perl.init ();
      rxvt_perl.eval (opt_eval);
    }
#endif

  // optionally open display and never release it.
  if (opt_opendisplay)
    if (const char *dpy = getenv ("DISPLAY"))
      displays.get (dpy ? dpy : ":0"); // move string logic into rxvt_display maybe?

  int fd;
#ifdef ENABLE_FRILLS
  int n = get_listen_fds ();
  if (n > 1)
    {
      fputs ("received multiple file descriptors, aborting.\n", stderr);
      exit (EXIT_FAILURE);
    }
  else if (n == 1)
    {
      fd = SD_LISTEN_FDS_START;
      if (!opt_quiet)
        {
          printf ("rxvt-unicode daemon listening on fd.\n");
          fflush (stdout);
        }
    }
  else
#endif
    {
      char *sockname = rxvt_connection::unix_sockname ();
      fd = unix_listener::open (sockname);
      if (!opt_quiet)
        {
          printf ("rxvt-unicode daemon listening on %s.\n", sockname);
          fflush (stdout);
        }
      free (sockname);
    }

  unix_listener l (fd);

  chdir ("/");

  pid_t pid = 0;
  if (opt_fork)
    {
      pid = fork ();
    }

#if ENABLE_MLOCK
  // Optionally perform an mlockall so this process does not get swapped out.
  if (opt_lock && !pid)
    if (mlockall (MCL_CURRENT | MCL_FUTURE) < 0)
      perror ("unable to lock into ram");
#endif

  if (opt_fork)
    {
      if (pid < 0)
        {
          rxvt_log ("unable to fork daemon, aborting.\n");
          return EXIT_FAILURE;
        }
      else if (pid > 0)
        _exit (EXIT_SUCCESS);

      ev_loop_fork (EV_DEFAULT_UC);
    }

  ev_run ();

  return EXIT_SUCCESS;
}

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
#	User	Rev	Content
1	root	1.29	/----------------------------------------------------------------------
2	pcg	1.14	* File: rxvtd.C
3			----------------------------------------------------------------------
4			*
5			* All portions of code are copyright by their respective author/s.
6	root	1.56	* Copyright (c) 2003-2007 Marc Lehmann <schmorp@schmorp.de>
7	pcg	1.14	*
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	root	1.61	* the Free Software Foundation; either version 3 of the License, or
11	pcg	1.14	* (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	pcg	1.9	#include "../config.h"
24	sf-exg	1.59	#include <stdio.h>
25			#include <stdlib.h>
26			#include <stdarg.h>
27			#include <string.h>
28	pcg	1.1
29			#include <unistd.h>
30	pcg	1.12	#include <fcntl.h>
31	pcg	1.5	#include <sys/types.h>
32			#include <sys/stat.h>
33	pcg	1.1	#include <sys/socket.h>
34			#include <sys/un.h>
35
36	root	1.47	#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	sf-exg	1.59	#include <errno.h>
45	pcg	1.3
46	root	1.27	#include "rxvt.h"
47			#include "rxvtdaemon.h"
48			#include "libptytty.h"
49	pcg	1.3
50	pcg	1.1	struct server : rxvt_connection {
51	pcg	1.10	log_callback log_cb;
52	root	1.22	getfd_callback getfd_cb;
53	pcg	1.10
54	root	1.34	void read_cb (ev::io &w, int revents); ev::io read_ev;
55	pcg	1.10	void log_msg (const char *msg);
56	root	1.22	int getfd (int remote_fd);
57	pcg	1.1
58			server (int fd)
59			{
60	root	1.41	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	root	1.37	this->fd = fd;
65	root	1.35	fcntl (fd, F_SETFD, FD_CLOEXEC);
66			fcntl (fd, F_SETFL, 0);
67	root	1.34	read_ev.start (fd, ev::READ);
68	pcg	1.1	}
69
70	pcg	1.3	void err (const char *format = 0, ...);
71	pcg	1.1	};
72
73	pcg	1.5	struct unix_listener {
74	pcg	1.1	int fd;
75
76	root	1.34	void accept_cb (ev::io &w, int revents); ev::io accept_ev;
77	pcg	1.1
78	sf-exg	1.63	unix_listener (int fd);
79			static int open (const char *sockname);
80	pcg	1.1	};
81
82	sf-exg	1.63	unix_listener::unix_listener (int fd) : fd (fd)
83	pcg	1.1	{
84	root	1.41	accept_ev.set<unix_listener, &unix_listener::accept_cb> (this);
85	sf-exg	1.63	fcntl (fd, F_SETFD, FD_CLOEXEC);
86			fcntl (fd, F_SETFL, O_NONBLOCK);
87			accept_ev.start (fd, ev::READ);
88			}
89	root	1.41
90	sf-exg	1.63	int unix_listener::open (const char *sockname)
91			{
92	root	1.30	sockaddr_un sa;
93	ayin	1.33
94	root	1.31	if (strlen (sockname) >= sizeof(sa.sun_path))
95			{
96			fputs ("socket name too long, aborting.\n", stderr);
97			exit (EXIT_FAILURE);
98			}
99	root	1.30
100	sf-exg	1.63	int fd;
101	root	1.24	if ((fd = socket (AF_UNIX, SOCK_STREAM, 0)) < 0)
102	pcg	1.1	{
103			perror ("unable to create listening socket");
104			exit (EXIT_FAILURE);
105			}
106
107			sa.sun_family = AF_UNIX;
108	pcg	1.5	strcpy (sa.sun_path, sockname);
109	pcg	1.1
110	sf-exg	1.55	unlink (sockname);
111	pcg	1.1
112	pcg	1.5	mode_t omask = umask (0077);
113
114	pcg	1.1	if (bind (fd, (sockaddr *)&sa, sizeof (sa)))
115			{
116			perror ("unable to bind listening socket");
117			exit (EXIT_FAILURE);
118			}
119
120	pcg	1.5	umask (omask);
121
122	pcg	1.1	if (listen (fd, 5))
123			{
124			perror ("unable to listen on socket");
125			exit (EXIT_FAILURE);
126			}
127
128	sf-exg	1.63	return fd;
129	pcg	1.1	}
130
131	root	1.34	void unix_listener::accept_cb (ev::io &w, int revents)
132	pcg	1.1	{
133			int fd2 = accept (fd, 0, 0);
134
135			if (fd2 >= 0)
136	root	1.35	new server (fd2);
137	pcg	1.1	}
138
139	root	1.22	int server::getfd (int remote_fd)
140			{
141			send ("GETFD");
142			send (remote_fd);
143	root	1.27	return ptytty::recv_fd (fd);
144	root	1.22	}
145
146	pcg	1.10	void server::log_msg (const char *msg)
147			{
148			send ("MSG"), send (msg);
149			}
150
151	pcg	1.3	void server::err (const char *format, ...)
152	pcg	1.1	{
153	pcg	1.3	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	root	1.32	log_msg (err);
163	pcg	1.3	}
164
165	root	1.32	send ("END"), send (0);
166	pcg	1.1	close (fd);
167			delete this;
168			}
169
170	root	1.34	void server::read_cb (ev::io &w, int revents)
171	pcg	1.1	{
172	pcg	1.2	auto_str tok;
173	pcg	1.1
174	pcg	1.2	if (recv (tok))
175	pcg	1.1	{
176	pcg	1.2	if (!strcmp (tok, "NEW"))
177	pcg	1.1	{
178	pcg	1.9	stringvec *argv = new stringvec;
179			stringvec *envv = new stringvec;
180	ayin	1.33
181	pcg	1.2	for (;;)
182			{
183			if (!recv (tok))
184			return err ();
185
186			if (!strcmp (tok, "END"))
187			break;
188	pcg	1.3	else if (!strcmp (tok, "ENV") && recv (tok))
189	root	1.26	envv->push_back (strdup (tok));
190	pcg	1.2	else if (!strcmp (tok, "ARG") && recv (tok))
191	root	1.26	argv->push_back (strdup (tok));
192	pcg	1.2	else
193	root	1.31	return err ("protocol error: unexpected NEW token.\n");
194	pcg	1.2	}
195
196	pcg	1.3	{
197	pcg	1.10	rxvt_term *term = new rxvt_term;
198	ayin	1.33
199	pcg	1.10	term->log_hook = &log_cb;
200	root	1.22	term->getfd_hook = &getfd_cb;
201	pcg	1.2
202	root	1.42	bool success = true;
203	ayin	1.33
204	pcg	1.10	try
205			{
206	root	1.42	term->init (argv, envv);
207	pcg	1.10	}
208			catch (const class rxvt_failure_exception &e)
209			{
210			success = false;
211			}
212
213	root	1.15	term->log_hook = 0;
214
215	root	1.46	chdir ("/"); // init might change to different working directory
216	pcg	1.10
217			if (!success)
218			term->destroy ();
219
220			send ("END"); send (success ? 1 : 0);
221	pcg	1.3	}
222	pcg	1.1	}
223	sf-exg	1.62	else if (!strcmp (tok, "QUIT"))
224			_exit (0);
225	pcg	1.1	else
226	root	1.31	return err ("protocol error: request '%s' unsupported.\n", (char *)tok);
227	pcg	1.1	}
228			else
229	pcg	1.2	return err ();
230	pcg	1.1	}
231
232	sf-exg	1.63	#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	sf-exg	1.49	int
275	root	1.58	main (int argc, char *argv[])
276	sf-exg	1.49	{
277	root	1.52	ptytty::init ();
278
279	sf-exg	1.54	static char opt_fork, opt_opendisplay, opt_quiet;
280	root	1.60	#if ENABLE_PERL
281			static char *opt_eval;
282			#endif
283	root	1.47	#if ENABLE_MLOCK
284	sf-exg	1.54	static char opt_lock;
285	root	1.47	#endif
286	root	1.21
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	root	1.47	#if ENABLE_MLOCK
296			else if (!strcmp (argv [i], "-m") \|\| !strcmp (argv [i], "--mlock"))
297			opt_lock = 1;
298			#endif
299	root	1.60	#if ENABLE_PERL
300			else if (!strcmp (argv [i], "-e") \|\| !strcmp (argv [i], "--eval"))
301			opt_eval = argv [++i];
302			#endif
303	root	1.21	else
304			{
305			rxvt_log ("%s: unknown option '%s', aborting.\n", argv [0], argv [i]);
306			return EXIT_FAILURE;
307			}
308			}
309	ayin	1.33
310	root	1.52	rxvt_init ();
311
312	root	1.60	#if ENABLE_PERL
313			if (opt_eval)
314			{
315			rxvt_perl.init ();
316			rxvt_perl.eval (opt_eval);
317			}
318			#endif
319
320	root	1.45	// optionally open display and never release it.
321	root	1.21	if (opt_opendisplay)
322	root	1.45	if (const char *dpy = getenv ("DISPLAY"))
323			displays.get (dpy ? dpy : ":0"); // move string logic into rxvt_display maybe?
324	root	1.21
325	sf-exg	1.63	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	root	1.21	{
345	sf-exg	1.63	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	root	1.21	}
354
355	sf-exg	1.63	unix_listener l (fd);
356
357			chdir ("/");
358	pcg	1.5
359	root	1.47	pid_t pid = 0;
360	root	1.21	if (opt_fork)
361			{
362	root	1.47	pid = fork ();
363			}
364
365			#if ENABLE_MLOCK
366	root	1.48	// 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	root	1.47	#endif
371	root	1.21
372	root	1.47	if (opt_fork)
373			{
374	root	1.21	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	root	1.38
382	root	1.51	ev_loop_fork (EV_DEFAULT_UC);
383	root	1.21	}
384
385	root	1.50	ev_run ();
386	pcg	1.1
387			return EXIT_SUCCESS;
388			}
389	pcg	1.7