This is gnuserv.c in view mode; [Download] [Up]
/* -*-C-*-
Server code for handling requests from clients and forwarding them
on to the GNU Emacs process.
This file is part of GNU Emacs.
Copying is permitted under those conditions described by the GNU
General Public License.
Copyright (C) 1989 Free Software Foundation, Inc.
Author: Andy Norman (ange@hplb.hpl.hp.com), based on 'etc/server.c'
from the 18.52 GNU Emacs distribution.
Please mail bugs and suggestions to the author at the above address.
*/
/* HISTORY
* 11-Nov-1990 bristor@simba
* Added EOT stuff.
*/
/*
* This file incorporates new features added by Bob Weiner <weiner@mot.com>,
* Darrell Kindred <dkindred@cmu.edu> and Arup Mukherjee <arup@cmu.edu>.
* Please see the note at the end of the README file for details.
*
* (If gnuserv came bundled with your emacs, the README file is probably
* ../etc/gnuserv.README relative to the directory containing this file)
*/
#if 0
static char rcsid [] = "!Header: gnuserv.c,v 2.1 95/02/16 11:58:27 arup alpha !";
#endif
#include "gnuserv.h"
#ifdef USE_LITOUT
#ifdef linux
#include <bsd/sgtty.h>
#else
#include <sgtty.h>
#endif
#endif
#ifdef AIX
#include <sys/select.h>
#endif
#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <string.h>
#if !defined(SYSV_IPC) && !defined(UNIX_DOMAIN_SOCKETS) && \
!defined(INTERNET_DOMAIN_SOCKETS)
main ()
{
fprintf (stderr,"Sorry, the Emacs server is only supported on systems that have\n");
fprintf (stderr,"Unix Domain sockets, Internet Domain sockets or System V IPC\n");
exit (1);
} /* main */
#else /* SYSV_IPC || UNIX_DOMAIN_SOCKETS || INTERNET_DOMAIN_SOCKETS */
#ifdef SYSV_IPC
int ipc_qid = 0; /* ipc message queue id */
int ipc_wpid = 0; /* watchdog task pid */
/*
ipc_exit -- clean up the queue id and queue, then kill the watchdog task
if it exists. exit with the given status.
*/
void ipc_exit(stat)
int stat;
{
msgctl(ipc_qid,IPC_RMID,0);
if (ipc_wpid != 0)
kill(ipc_wpid,SIGKILL);
exit(stat);
} /* ipc_exit */
/*
ipc_handle_signal -- catch the signal given and clean up.
*/
void ipc_handle_signal(sig)
int sig;
{
ipc_exit(0);
} /* ipc_handle_signal */
/*
ipc_spawn_watchdog -- spawn a watchdog task to clean up the message queue should the
server process die.
*/
void ipc_spawn_watchdog()
{
if ((ipc_wpid = fork()) == 0) { /* child process */
int ppid = getppid(); /* parent's process id */
setpgrp(); /* gnu kills process group on exit */
while (1) {
if (kill(ppid,0) < 0) { /* ppid is no longer valid, parent may have died */
ipc_exit(0);
}; /* if */
sleep(10); /* have another go later */
}; /* while */
}; /* if */
} /* ipc_spawn_watchdog */
/*
ipc_init -- initialize server, setting the global msqid that can be listened on.
*/
void ipc_init(msgpp)
struct msgbuf **msgpp;
{
key_t key; /* messge key */
char buf[GSERV_BUFSZ]; /* pathname for key */
sprintf(buf,"/tmp/gsrv%d",(int)geteuid());
creat(buf,0600);
key = ftok(buf,1);
if ((ipc_qid = msgget(key,0600|IPC_CREAT)) == -1) {
perror(progname);
fprintf(stderr,"%s: unable to create msg queue\n",progname);
ipc_exit(1);
}; /* if */
ipc_spawn_watchdog();
signal(SIGTERM,ipc_handle_signal);
signal(SIGINT,ipc_handle_signal);
if ((*msgpp = (struct msgbuf *)
malloc(sizeof **msgpp + GSERV_BUFSZ)) == NULL) {
fprintf(stderr,
"%s: unable to allocate space for message buffer\n",progname);
ipc_exit(1);
}; /* if */
} /* ipc_init */
/*
handle_ipc_request -- accept a request from a client, pass the request on
to the GNU Emacs process, then wait for its reply and
pass that on to the client.
*/
void handle_ipc_request(msgp)
struct msgbuf *msgp; /* message buffer */
{
struct msqid_ds msg_st; /* message status */
char buf[GSERV_BUFSZ];
int len; /* length of message / read */
int s, result_len; /* tag fields on the response from emacs */
int offset = 0;
int total = 1; /* # bytes that will actually be sent off */
if ((len = msgrcv(ipc_qid,msgp,GSERV_BUFSZ-1,1,0)) < 0) {
perror(progname);
fprintf(stderr,"%s: unable to receive\n",progname);
ipc_exit(1);
}; /* if */
msgctl(ipc_qid,IPC_STAT,&msg_st);
strncpy(buf,msgp->mtext,len);
buf[len] = '\0'; /* terminate */
printf("%d %s",ipc_qid,buf);
fflush(stdout);
/* now for the response from gnu */
msgp->mtext[0] = '\0';
#if 0
if ((len = read(0,buf,GSERV_BUFSZ)) < 0) {
perror(progname);
fprintf(stderr,"%s: unable to read\n",progname);
ipc_exit(1);
}; /* if */
sscanf(buf,"%d:%[^\n]\n",&junk,msgp->mtext);
#else
/* read in "n/m:" (n=client fd, m=message length) */
while (offset < GSERV_BUFSZ &&
((len = read(0,buf+offset,1)) > 0) &&
buf[offset] != ':') {
offset += len;
}
if (len < 0) {
perror(progname);
fprintf(stderr,"%s: unable to read\n",progname);
exit(1);
}
/* parse the response from emacs, getting client fd & result length */
buf[offset] = '\0';
sscanf(buf,"%d/%d", &s, &result_len);
while (result_len > 0) {
if ((len = read(0,buf,min2(result_len, GSERV_BUFSZ - 1))) < 0) {
perror(progname);
fprintf(stderr,"%s: unable to read\n",progname);
exit(1);
}
/* Send this string off, but only if we have enough space */
if (GSERV_BUFSZ > total) {
if (total + len <= GSERV_BUFSZ)
buf[len] = 0;
else
buf[GSERV_BUFSZ - total] = 0;
send_string(s,buf);
total += strlen(buf);
};
result_len -= len;
}
/* eat the newline */
while ((len = read(0,buf,1)) == 0)
;
if (len < 0) {
perror(progname);
fprintf(stderr,"%s: unable to read\n",progname);
exit(1);
}
if (buf[0] != '\n') {
fprintf(stderr,"%s: garbage after result [%c]\n",progname, buf[0]);
exit(1);
}
#endif
/* Send a response back to the client. */
msgp->mtype = msg_st.msg_lspid;
if (msgsnd(ipc_qid,msgp,strlen(msgp->mtext)+1,0) < 0)
perror("msgsend(gnuserv)");
} /* handle_ipc_request */
#endif /* SYSV_IPC */
#if defined(INTERNET_DOMAIN_SOCKETS) || defined(UNIX_DOMAIN_SOCKETS)
/*
echo_request -- read request from a given socket descriptor, and send the information
to stdout (the gnu process).
*/
static void
echo_request (int s)
{
char buf[GSERV_BUFSZ];
int len;
printf("%d ",s);
/* read until we get a newline or no characters */
while ((len = recv(s,buf,GSERV_BUFSZ,0)) > 0) {
buf[len] = '\0';
printf("%s",buf);
if (buf[len-1] == EOT_CHR) {
fflush(stdout);
break; /* end of message */
}
}; /* while */
if (len < 0) {
perror(progname);
fprintf(stderr,"%s: unable to recv\n",progname);
exit(1);
}; /* if */
} /* echo_request */
/*
handle_response -- accept a response from stdin (the gnu process) and pass the
information on to the relevant client.
*/
static void
handle_response (void)
{
char buf[GSERV_BUFSZ+1];
int offset=0;
int s;
int len;
int result_len;
/* read in "n/m:" (n=client fd, m=message length) */
while (offset < GSERV_BUFSZ &&
((len = read(0,buf+offset,1)) > 0) &&
buf[offset] != ':') {
offset += len;
}
if (len < 0) {
perror(progname);
fprintf(stderr,"%s: unable to read\n",progname);
exit(1);
}
/* parse the response from emacs, getting client fd & result length */
buf[offset] = '\0';
sscanf(buf,"%d/%d", &s, &result_len);
while (result_len > 0) {
if ((len = read(0,buf,min2(result_len,GSERV_BUFSZ))) < 0) {
perror(progname);
fprintf(stderr,"%s: unable to read\n",progname);
exit(1);
}
buf[len] = '\0';
send_string(s,buf);
result_len -= len;
}
/* eat the newline */
while ((len = read(0,buf,1)) == 0)
;
if (len < 0) {
perror(progname);
fprintf(stderr,"%s: unable to read\n",progname);
exit(1);
}
if (buf[0] != '\n') {
fprintf(stderr,"%s: garbage after result\n",progname);
exit(1);
}
close(s);
} /* handle_response */
#endif /* INTERNET_DOMAIN_SOCKETS || UNIX_DOMAIN_SOCKETS */
#ifdef INTERNET_DOMAIN_SOCKETS
struct entry {
u_long host_addr;
struct entry *next;
};
struct entry *permitted_hosts[TABLE_SIZE];
#ifdef AUTH_MAGIC_COOKIE
# include <X11/X.h>
# include <X11/Xauth.h>
static Xauth *server_xauth = NULL;
#endif
static int
timed_read (int fd, char *buf, int max, int timeout, int one_line)
{
fd_set rmask;
struct timeval tv; /* = {timeout, 0}; */
char c = 0;
int nbytes = 0;
int r;
tv.tv_sec = timeout;
tv.tv_usec = 0;
FD_ZERO(&rmask);
FD_SET(fd, &rmask);
do {
r = select(fd + 1, &rmask, NULL, NULL, &tv);
if (r > 0) {
if (read (fd, &c, 1) == 1 ){
*buf++ = c;
++nbytes;
} else {
printf ("read error on socket\004\n");
return -1;
}
} else if (r == 0) {
printf ("read timed out\004\n");
return -1;
} else {
printf ("error in select\004\n");
return -1;
}
} while ((nbytes < max) && !(one_line && (c == '\n')));
--buf;
if (one_line && *buf == '\n') {
*buf = 0;
}
return nbytes;
}
/*
permitted -- return whether a given host is allowed to connect to the server.
*/
static int
permitted (u_long host_addr, int fd)
{
int key;
struct entry *entry;
char auth_protocol[128];
char buf[1024];
int auth_data_len;
if (fd > 0) {
/* we are checking permission on a real connection */
/* Read auth protocol name */
if (timed_read(fd, auth_protocol, AUTH_NAMESZ, AUTH_TIMEOUT, 1) <= 0)
return FALSE;
if (strcmp (auth_protocol, DEFAUTH_NAME) &&
strcmp (auth_protocol, MCOOKIE_NAME)) {
printf ("authentication protocol (%s) from client is invalid...\n",
auth_protocol);
printf ("... Was the client an old version of gnuclient/gnudoit?\004\n");
return FALSE;
}
if (!strcmp(auth_protocol, MCOOKIE_NAME)) {
/*
* doing magic cookie auth
*/
if (timed_read(fd, buf, 10, AUTH_TIMEOUT, 1) <= 0)
return FALSE;
auth_data_len = atoi(buf);
if (timed_read(fd, buf, auth_data_len, AUTH_TIMEOUT, 0) != auth_data_len)
return FALSE;
#ifdef AUTH_MAGIC_COOKIE
if (server_xauth && server_xauth->data &&
!memcmp(buf, server_xauth->data, auth_data_len)) {
return TRUE;
}
#else
printf ("client tried Xauth, but server is not compiled with Xauth\n");
#endif
/*
* auth failed, but allow this to fall through to the GNU_SECURE
* protocol....
*/
printf ("Xauth authentication failed, trying GNU_SECURE auth...\004\n");
}
/* Other auth protocols go here, and should execute only if the
* auth_protocol name matches.
*/
}
/* Now, try the old GNU_SECURE stuff... */
/* First find the hash key */
key = HASH(host_addr) % TABLE_SIZE;
/* Now check the chain for that hash key */
for(entry=permitted_hosts[key]; entry != NULL; entry=entry->next)
if (host_addr == entry->host_addr)
return(TRUE);
return(FALSE);
} /* permitted */
/*
add_host -- add the given host to the list of permitted hosts, provided it isn't
already there.
*/
static void
add_host (u_long host_addr)
{
int key;
struct entry *new_entry;
if (!permitted(host_addr, -1)) {
if ((new_entry = (struct entry *) malloc(sizeof(struct entry))) == NULL) {
fprintf(stderr,"%s: unable to malloc space for permitted host entry\n",
progname);
exit(1);
}; /* if */
new_entry->host_addr = host_addr;
key = HASH(host_addr) % TABLE_SIZE;
new_entry->next = permitted_hosts[key];
permitted_hosts[key] = new_entry;
}; /* if */
} /* add_host */
/*
setup_table -- initialise the table of hosts allowed to contact the server,
by reading from the file specified by the GNU_SECURE
environment variable
Put in the local machine, and, if a security file is specifed,
add each host that is named in the file.
Return the number of hosts added.
*/
static int
setup_table (void)
{
FILE *host_file;
char *file_name;
char hostname[HOSTNAMSZ];
u_int host_addr;
int i, hosts=0;
/* Make sure every entry is null */
for (i=0; i<TABLE_SIZE; i++)
permitted_hosts[i] = NULL;
gethostname(hostname,HOSTNAMSZ);
if ((host_addr = internet_addr(hostname)) == -1) {
fprintf(stderr,"%s: unable to find %s in /etc/hosts or from YP",
progname,hostname);
exit(1);
}; /* if */
#ifdef AUTH_MAGIC_COOKIE
server_xauth = XauGetAuthByAddr (FamilyInternet,
sizeof(host_addr), (char *)&host_addr,
strlen(MCOOKIE_SCREEN), MCOOKIE_SCREEN,
strlen(MCOOKIE_X_NAME), MCOOKIE_X_NAME);
hosts++;
#endif /* AUTH_MAGIC_COOKIE */
#if 0 /* Don't even want to allow access from the local host by default */
add_host(host_addr); /* add local host */
#endif
if (((file_name = getenv("GNU_SECURE")) != NULL && /* security file */
(host_file = fopen(file_name,"r")) != NULL)) { /* opened ok */
while ((fscanf(host_file,"%s",hostname) != EOF)) /* find a host */
if ((host_addr = internet_addr(hostname)) != -1) {/* get its addr */
add_host(host_addr); /* add the addr */
hosts++;
}
fclose(host_file);
}; /* if */
return hosts;
} /* setup_table */
/*
internet_init -- initialize server, returning an internet socket that can
be listened on.
*/
static int
internet_init (void)
{
int ls; /* socket descriptor */
struct servent *sp; /* pointer to service information */
struct sockaddr_in server; /* for local socket address */
char *ptr; /* ptr to return from getenv */
if (setup_table() == 0)
return -1;
/* clear out address structure */
memset((char *)&server,0,sizeof(struct sockaddr_in));
/* Set up address structure for the listen socket. */
server.sin_family = AF_INET;
server.sin_addr.s_addr = INADDR_ANY;
/* Find the information for the gnu server
* in order to get the needed port number.
*/
if ((ptr=getenv("GNU_PORT")) != NULL)
server.sin_port = htons(atoi(ptr));
else if ((sp = getservbyname ("gnuserv", "tcp")) == NULL)
server.sin_port = htons(DEFAULT_PORT+getuid());
else
server.sin_port = sp->s_port;
/* Create the listen socket. */
if ((ls = socket (AF_INET,SOCK_STREAM, 0)) == -1) {
perror(progname);
fprintf(stderr,"%s: unable to create socket\n",progname);
exit(1);
}; /* if */
/* Bind the listen address to the socket. */
if (bind(ls,(struct sockaddr *) &server,sizeof(struct sockaddr_in)) == -1) {
perror(progname);
fprintf(stderr,"%s: unable to bind socket\n",progname);
exit(1);
}; /* if */
/* Initiate the listen on the socket so remote users
* can connect.
*/
if (listen(ls,20) == -1) {
perror(progname);
fprintf(stderr,"%s: unable to listen\n",progname);
exit(1);
}; /* if */
return(ls);
} /* internet_init */
/*
handle_internet_request -- accept a request from a client and send the information
to stdout (the gnu process).
*/
static void
handle_internet_request (int ls)
{
int s;
int addrlen = sizeof(struct sockaddr_in);
struct sockaddr_in peer; /* for peer socket address */
memset((char *)&peer,0,sizeof(struct sockaddr_in));
if ((s = accept(ls,(struct sockaddr *)&peer,&addrlen)) == -1) {
perror(progname);
fprintf(stderr,"%s: unable to accept\n",progname);
exit(1);
}; /* if */
/* Check that access is allowed - if not return crud to the client */
if (!permitted(peer.sin_addr.s_addr, s)) {
send_string(s,"gnudoit: Connection refused\ngnudoit: unable to connect to remote");
close(s);
printf("Refused connection from %s\004\n", inet_ntoa(peer.sin_addr));
return;
}; /* if */
echo_request(s);
} /* handle_internet_request */
#endif /* INTERNET_DOMAIN_SOCKETS */
#ifdef UNIX_DOMAIN_SOCKETS
/*
unix_init -- initialize server, returning an unix-domain socket that can
be listened on.
*/
static int
unix_init (void)
{
int ls; /* socket descriptor */
struct sockaddr_un server; /* unix socket address */
if ((ls = socket(AF_UNIX,SOCK_STREAM, 0)) < 0) {
perror(progname);
fprintf(stderr,"%s: unable to create socket\n",progname);
exit(1);
}; /* if */
/* Set up address structure for the listen socket. */
#ifdef HIDE_UNIX_SOCKET
sprintf(server.sun_path,"/tmp/gsrvdir%d",(int)geteuid());
if (mkdir(server.sun_path, 0700) < 0) {
/* assume it already exists, and try to set perms */
if (chmod(server.sun_path, 0700) < 0) {
perror(progname);
fprintf(stderr,"%s: can't set permissions on %s\n",
progname, server.sun_path);
exit(1);
}
}
strcat(server.sun_path,"/gsrv");
unlink(server.sun_path); /* remove old file if it exists */
#else /* HIDE_UNIX_SOCKET */
sprintf(server.sun_path,"/tmp/gsrv%d",(int)geteuid());
unlink(server.sun_path); /* remove old file if it exists */
#endif /* HIDE_UNIX_SOCKET */
server.sun_family = AF_UNIX;
if (bind(ls,(struct sockaddr *)&server,strlen(server.sun_path)+2) < 0) {
perror(progname);
fprintf(stderr,"%s: unable to bind socket\n",progname);
exit(1);
}; /* if */
chmod(server.sun_path,0700); /* only this user can send commands */
if (listen(ls,20) < 0) {
perror(progname);
fprintf(stderr,"%s: unable to listen\n",progname);
exit(1);
}; /* if */
signal(SIGPIPE,SIG_IGN); /* in case user kills client */
return(ls);
} /* unix_init */
/*
handle_unix_request -- accept a request from a client and send the information
to stdout (the gnu process).
*/
static void
handle_unix_request (int ls)
{
int s;
int len = sizeof(struct sockaddr_un);
struct sockaddr_un server; /* for unix socket address */
server.sun_family = AF_UNIX;
if ((s = accept(ls,(struct sockaddr *)&server,&len)) < 0) {
perror(progname);
fprintf(stderr,"%s: unable to accept\n",progname);
}; /* if */
echo_request(s);
} /* handle_unix_request */
#endif /* UNIX_DOMAIN_SOCKETS */
void
main(argc,argv)
int argc;
char *argv[];
{
int chan; /* temporary channel number */
#ifdef INTERNET_DOMAIN_SOCKETS
int ils = -1; /* internet domain listen socket */
#endif
#ifdef UNIX_DOMAIN_SOCKETS
int uls = -1; /* unix domain listen socket */
#endif
#ifdef SYSV_IPC
struct msgbuf *msgp; /* message buffer */
#endif /* SYSV_IPC */
progname = argv[0];
for(chan=3; chan < _NFILE; close(chan++)) /* close unwanted channels */
;
#ifdef USE_LITOUT
{
/* this is to allow ^D to pass to emacs */
int d = LLITOUT;
(void) ioctl(fileno(stdout), TIOCLBIS, &d);
}
#endif
#ifdef SYSV_IPC
ipc_init(&msgp); /* get a msqid to listen on, and a message buffer */
#endif /* SYSV_IPC */
#ifdef INTERNET_DOMAIN_SOCKETS
ils = internet_init(); /* get a internet domain socket to listen on */
#endif /* INTERNET_DOMAIN_SOCKETS */
#ifdef UNIX_DOMAIN_SOCKETS
uls = unix_init(); /* get a unix domain socket to listen on */
#endif /* UNIX_DOMAIN_SOCKETS */
while (1) {
#ifdef SYSV_IPC
handle_ipc_request(msgp);
#else /* NOT SYSV_IPC */
fd_set rmask;
FD_ZERO(&rmask);
FD_SET(fileno(stdin), &rmask);
if (uls >= 0)
FD_SET(uls, &rmask);
if (ils >= 0)
FD_SET(ils, &rmask);
if (select(max2(fileno(stdin),max2(uls,ils)) + 1, &rmask,
(fd_set *)NULL, (fd_set *)NULL, (struct timeval *)NULL) < 0) {
perror(progname);
fprintf(stderr,"%s: unable to select\n",progname);
exit(1);
}; /* if */
#ifdef UNIX_DOMAIN_SOCKETS
if (uls > 0 && FD_ISSET(uls, &rmask))
handle_unix_request(uls);
#endif
#ifdef INTERNET_DOMAIN_SOCKETS
if (ils > 0 && FD_ISSET(ils, &rmask))
handle_internet_request(ils);
#endif /* INTERNET_DOMAIN_SOCKETS */
if (FD_ISSET(fileno(stdin), &rmask)) /* from stdin (gnu process) */
handle_response();
#endif /* NOT SYSV_IPC */
}; /* while */
} /* main */
#endif /* SYSV_IPC || UNIX_DOMAIN_SOCKETS || INTERNET_DOMAIN_SOCKETS */
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.