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emacs/lib-src/emacsserver.c
Andreas Schwab 4e7ef1d6c5 Include <unistd.h> if available.
(main, handle_signals, perror_1, fatal_error): Explicitly declare
return types.  Add forward declarations.
1998-04-06 10:14:26 +00:00

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/* Communication subprocess for GNU Emacs acting as server.
Copyright (C) 1986, 1987, 1992, 1994 Free Software Foundation, Inc.
This file is part of GNU Emacs.
GNU Emacs 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 2, or (at your option)
any later version.
GNU Emacs 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 GNU Emacs; see the file COPYING. If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
/* The GNU Emacs edit server process is run as a subprocess of Emacs
under control of the file lisp/server.el.
This program accepts communication from client (program emacsclient.c)
and passes their commands (consisting of keyboard characters)
up to the Emacs which then executes them. */
#define NO_SHORTNAMES
#include <signal.h>
#include <../src/config.h>
#undef read
#undef write
#undef open
#undef close
#undef signal
#if !defined (HAVE_SOCKETS) && !defined (HAVE_SYSVIPC)
#include <stdio.h>
int
main ()
{
fprintf (stderr, "Sorry, the Emacs server is supported only on systems\n");
fprintf (stderr, "with Berkeley sockets or System V IPC.\n");
exit (1);
}
#else /* HAVE_SOCKETS or HAVE_SYSVIPC */
void perror_1 ();
void fatal_error ();
#if defined (HAVE_SOCKETS) && ! defined (NO_SOCKETS_IN_FILE_SYSTEM)
/* BSD code is very different from SYSV IPC code */
#include <sys/types.h>
#include <sys/file.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <stdio.h>
#include <errno.h>
#include <sys/stat.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
extern int errno;
/* Copied from src/process.c */
#ifdef FD_SET
/* We could get this from param.h, but better not to depend on finding that.
And better not to risk that it might define other symbols used in this
file. */
#ifdef FD_SETSIZE
#define MAXDESC FD_SETSIZE
#else
#define MAXDESC 64
#endif
#define SELECT_TYPE fd_set
#else /* no FD_SET */
#define MAXDESC 32
#define SELECT_TYPE int
/* Define the macros to access a single-int bitmap of descriptors. */
#define FD_SET(n, p) (*(p) |= (1 << (n)))
#define FD_CLR(n, p) (*(p) &= ~(1 << (n)))
#define FD_ISSET(n, p) (*(p) & (1 << (n)))
#define FD_ZERO(p) (*(p) = 0)
#endif /* no FD_SET */
/* This is the file name of the socket that we made. */
char *socket_name;
/* Name of this program. */
char *progname;
/* Handle fatal signals. */
/* This is the handler. */
SIGTYPE
delete_socket (sig)
int sig;
{
signal (sig, SIG_DFL);
unlink (socket_name);
kill (getpid (), sig);
}
/* Set up to handle all the signals. */
void
handle_signals ()
{
signal (SIGHUP, delete_socket);
signal (SIGINT, delete_socket);
signal (SIGQUIT, delete_socket);
signal (SIGILL, delete_socket);
signal (SIGTRAP, delete_socket);
#ifdef SIGABRT
signal (SIGABRT, delete_socket);
#endif
#ifdef SIGHWE
signal (SIGHWE, delete_socket);
#endif
#ifdef SIGPRE
signal (SIGPRE, delete_socket);
#endif
#ifdef SIGORE
signal (SIGORE, delete_socket);
#endif
#ifdef SIGUME
signal (SIGUME, delete_socket);
#endif
#ifdef SIGDLK
signal (SIGDLK, delete_socket);
#endif
#ifdef SIGCPULIM
signal (SIGCPULIM, delete_socket);
#endif
#ifdef SIGIOT
/* This is missing on some systems - OS/2, for example. */
signal (SIGIOT, delete_socket);
#endif
#ifdef SIGEMT
signal (SIGEMT, delete_socket);
#endif
signal (SIGFPE, delete_socket);
#ifdef SIGBUS
signal (SIGBUS, delete_socket);
#endif
signal (SIGSEGV, delete_socket);
#ifdef SIGSYS
signal (SIGSYS, delete_socket);
#endif
signal (SIGTERM, delete_socket);
#ifdef SIGXCPU
signal (SIGXCPU, delete_socket);
#endif
#ifdef SIGXFSZ
signal (SIGXFSZ, delete_socket);
#endif /* SIGXFSZ */
#ifdef AIX
/* 20 is SIGCHLD, 21 is SIGTTIN, 22 is SIGTTOU. */
signal (SIGXCPU, delete_socket);
#ifndef _I386
signal (SIGIOINT, delete_socket);
#endif
signal (SIGGRANT, delete_socket);
signal (SIGRETRACT, delete_socket);
signal (SIGSOUND, delete_socket);
signal (SIGMSG, delete_socket);
#endif /* AIX */
}
/* Print error message. `s1' is printf control string, `s2' is arg for it. */
void
error (s1, s2)
char *s1, *s2;
{
fprintf (stderr, "%s: ", progname);
fprintf (stderr, s1, s2);
fprintf (stderr, "\n");
}
/* Print error message and exit. */
void
fatal (s1, s2)
char *s1, *s2;
{
error (s1, s2);
exit (1);
}
/* Like malloc but get fatal error if memory is exhausted. */
long *
xmalloc (size)
unsigned int size;
{
long *result = (long *) malloc (size);
if (result == NULL)
fatal ("virtual memory exhausted", 0);
return result;
}
int
main (argc, argv)
int argc;
char **argv;
{
char system_name[32];
int s, infd;
#ifdef SOCKLEN_TYPE
SOCKLEN_TYPE fromlen;
#else
size_t fromlen;
#endif
struct sockaddr_un server, fromunix;
char *homedir;
char *str, string[BUFSIZ], code[BUFSIZ];
FILE *infile;
FILE **openfiles;
int openfiles_size;
struct stat statbuf;
#ifndef convex
char *getenv ();
#endif
progname = argv[0];
openfiles_size = 20;
openfiles = (FILE **) malloc (openfiles_size * sizeof (FILE *));
if (openfiles == 0)
abort ();
/*
* Open up an AF_UNIX socket in this person's home directory
*/
if ((s = socket (AF_UNIX, SOCK_STREAM, 0)) < 0)
{
perror_1 ("socket");
exit (1);
}
server.sun_family = AF_UNIX;
#ifndef SERVER_HOME_DIR
gethostname (system_name, sizeof (system_name));
sprintf (server.sun_path, "/tmp/esrv%d-%s", geteuid (), system_name);
if (unlink (server.sun_path) == -1 && errno != ENOENT)
{
perror_1 ("unlink");
exit (1);
}
#else
if ((homedir = getenv ("HOME")) == NULL)
fatal_error ("No home directory\n");
strcpy (server.sun_path, homedir);
strcat (server.sun_path, "/.emacs-server-");
gethostname (system_name, sizeof (system_name));
strcat (server.sun_path, system_name);
/* Delete anyone else's old server. */
unlink (server.sun_path);
#endif
/* Save the socket name so we can delete it. */
socket_name = (char *) xmalloc (strlen (server.sun_path) + 1);
strcpy (socket_name, server.sun_path);
handle_signals ();
if (bind (s, (struct sockaddr *) &server, strlen (server.sun_path) + 2) < 0)
{
perror_1 ("bind");
exit (1);
}
/* Only this user can send commands to this Emacs. */
if (stat (server.sun_path, &statbuf) < 0)
{
perror_1 ("bind");
exit (1);
}
chmod (server.sun_path, statbuf.st_mode & 0600);
/*
* Now, just wait for everything to come in..
*/
if (listen (s, 5) < 0)
{
perror_1 ("listen");
exit (1);
}
/* Disable sigpipes in case luser kills client... */
signal (SIGPIPE, SIG_IGN);
for (;;)
{
SELECT_TYPE rmask;
FD_ZERO (&rmask);
FD_SET (0, &rmask);
FD_SET (s, &rmask);
if (select (s + 1, &rmask, 0, 0, 0) < 0)
perror_1 ("select");
if (FD_ISSET (s, &rmask)) /* client sends list of filenames */
{
fromlen = sizeof (fromunix);
fromunix.sun_family = AF_UNIX;
infd = accept (s, (struct sockaddr *) &fromunix, &fromlen);
if (infd < 0)
{
if (errno == EMFILE || errno == ENFILE)
fprintf (stderr, "Error: too many clients.\n");
else
perror_1 ("accept");
continue;
}
if (infd >= openfiles_size)
{
openfiles_size *= 2;
openfiles = (FILE **) realloc (openfiles,
openfiles_size * sizeof (FILE *));
if (openfiles == 0)
abort ();
}
infile = fdopen (infd, "r+"); /* open stream */
if (infile == NULL)
{
fprintf (stderr, "Error: too many clients.\n");
write (infd, "Too many clients.\n", 18);
close (infd); /* Prevent descriptor leak.. */
continue;
}
str = fgets (string, BUFSIZ, infile);
if (str == NULL)
{
perror_1 ("fgets");
close (infd); /* Prevent descriptor leak.. */
continue;
}
openfiles[infd] = infile;
printf ("Client: %d %s", infd, string);
/* If what we read did not end in a newline,
it means there is more. Keep reading from the socket
and outputting to Emacs, until we get the newline. */
while (string[strlen (string) - 1] != '\n')
{
if (fgets (string, BUFSIZ, infile) == 0)
break;
printf ("%s", string);
}
fflush (stdout);
fflush (infile);
continue;
}
else if (FD_ISSET (0, &rmask)) /* emacs sends codeword, fd, and string message */
{
/* Read command codeword and fd */
clearerr (stdin);
scanf ("%s %d%*c", code, &infd);
if (ferror (stdin) || feof (stdin))
fatal_error ("server: error reading from standard input\n");
/* Transfer text from Emacs to the client, up to a newline. */
infile = openfiles[infd];
rewind (infile);
while (1)
{
if (fgets (string, BUFSIZ, stdin) == 0)
break;
fprintf (infile, "%s", string);
if (string[strlen (string) - 1] == '\n')
break;
}
fflush (infile);
/* If command is close, close connection to client. */
if (strncmp (code, "Close:", 6) == 0)
if (infd > 2)
{
fclose (infile);
close (infd);
}
continue;
}
}
}
#else /* This is the SYSV IPC section */
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/msg.h>
#include <setjmp.h>
#include <errno.h>
#include <sys/utsname.h>
struct utsname system_name;
#ifndef errno
extern int errno;
#endif
jmp_buf msgenv;
SIGTYPE
msgcatch ()
{
longjmp (msgenv, 1);
}
/* "THIS has to be fixed. Remember, stderr may not exist...-rlk."
Incorrect. This program runs as an inferior of Emacs.
Its stderr always exists--rms. */
#include <stdio.h>
int
main ()
{
int s, infd, fromlen, ioproc;
key_t key;
struct msgbuf * msgp =
(struct msgbuf *) malloc (sizeof *msgp + BUFSIZ);
struct msqid_ds msg_st;
int p;
char *homedir, *getenv ();
char string[BUFSIZ];
FILE *infile;
/*
* Create a message queue using ~/.emacs-server as the path for ftok
*/
if ((homedir = getenv ("HOME")) == NULL)
fatal_error ("No home directory\n");
strcpy (string, homedir);
#ifndef HAVE_LONG_FILE_NAMES
/* If file names are short, we can't fit the host name. */
strcat (string, "/.emacs-server");
#else
strcat (string, "/.emacs-server-");
uname (&system_name);
strcat (string, system_name.nodename);
#endif
creat (string, 0600);
key = ftok (string, 1); /* unlikely to be anyone else using it */
s = msgget (key, 0600 | IPC_CREAT);
if (s == -1)
{
perror_1 ("msgget");
exit (1);
}
/* Fork so we can close connection even if parent dies */
p = fork ();
if (setjmp (msgenv))
{
msgctl (s, IPC_RMID, 0);
if (p > 0)
kill (p, SIGKILL);
exit (0);
}
signal (SIGTERM, msgcatch);
signal (SIGINT, msgcatch);
signal (SIGHUP, msgcatch);
if (p > 0)
{
/* This is executed in the original process that did the fork above. */
/* Get pid of Emacs itself. */
p = getppid ();
setpgrp (); /* Gnu kills process group on exit */
while (1)
{
/* Is Emacs still alive? */
if (kill (p, 0) < 0)
{
msgctl (s, IPC_RMID, 0);
exit (0);
}
sleep (10);
}
}
/* This is executed in the child made by forking above.
Call it c1. Make another process, ioproc. */
ioproc = fork ();
if (ioproc == 0)
{
/* In process ioproc, wait for text from Emacs,
and send it to the process c1.
This way, c1 only has to wait for one source of input. */
while (fgets (msgp->mtext, BUFSIZ, stdin))
{
msgp->mtype = 1;
msgsnd (s, msgp, strlen (msgp->mtext) + 1, 0);
}
exit (1);
}
/* In the process c1,
listen for messages from clients and pass them to Emacs. */
while (1)
{
if ((fromlen = msgrcv (s, msgp, BUFSIZ - 1, 1, 0)) < 0)
{
#ifdef EINTR
if (errno == EINTR)
continue;
#endif
perror_1 ("msgrcv");
exit (1);
}
else
{
msgctl (s, IPC_STAT, &msg_st);
/* Distinguish whether the message came from a client, or from
ioproc. */
if (msg_st.msg_lspid == ioproc)
{
char code[BUFSIZ];
int inproc;
/* Message from ioproc: tell a client we are done. */
msgp->mtext[strlen (msgp->mtext)-1] = 0;
sscanf (msgp->mtext, "%s %d", code, &inproc);
msgp->mtype = inproc;
msgsnd (s, msgp, strlen (msgp->mtext) + 1, 0);
continue;
}
/* This is a request from a client: copy to stdout
so that Emacs will get it. Include msg_lspid
so server.el can tell us where to send the reply. */
strncpy (string, msgp->mtext, fromlen);
string[fromlen] = 0; /* make sure */
/* Newline is part of string.. */
printf ("Client: %d %s", msg_st.msg_lspid, string);
fflush (stdout);
}
}
}
#endif /* HAVE_SYSVIPC */
#endif /* HAVE_SOCKETS or HAVE_SYSVIPC */
/* This is like perror but puts `Error: ' at the beginning. */
void
perror_1 (string)
char *string;
{
char *copy = (char *) malloc (strlen (string) + 8);
if (copy == 0)
fatal_error ("Virtual memory exhausted");
strcpy (copy, "Error: ");
strcat (copy, string);
perror (copy);
}
void
fatal_error (string)
char *string;
{
fprintf (stderr, "%s", "Error: ");
fprintf (stderr, string);
exit (1);
}