1
0
mirror of https://git.savannah.gnu.org/git/emacs.git synced 2024-12-12 09:28:24 +00:00
emacs/lib-src/emacsserver.c
2001-12-29 22:25:06 +00:00

600 lines
14 KiB
C
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/* Communication subprocess for GNU Emacs acting as server.
Copyright (C) 1986, 1987, 1992, 1994, 1999 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
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <signal.h>
#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
#ifndef errno
extern int errno;
#endif
/* 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;
int system_name_length;
int s, infd;
#ifdef SOCKLEN_TYPE
SOCKLEN_TYPE fromlen;
#else
size_t fromlen;
#endif
struct sockaddr_un server, fromunix;
#ifdef SERVER_HOME_DIR
char *homedir;
#endif
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;
system_name_length = 32;
while (1)
{
system_name = (char *) xmalloc (system_name_length + 1);
/* system_name must be null-terminated string. */
system_name[system_name_length] = '\0';
if (gethostname (system_name, system_name_length) == 0)
break;
free (system_name);
system_name_length *= 2;
}
#ifndef SERVER_HOME_DIR
sprintf (server.sun_path, "/tmp/esrv%d-%s", (int) 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-");
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 */
/* 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);
}
#endif /* HAVE_SOCKETS or HAVE_SYSVIPC */