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/* net.c --
* Created: Fri Feb 21 20:58:10 1997 by faith@cs.unc.edu
* Revised: Sun Jan 18 00:54:26 1998 by faith@acm.org
* Copyright 1997, 1998 Rickard E. Faith (faith@acm.org)
*
* 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 1, 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.
*
* $Id: net.c,v 1.18 1998/01/19 03:37:23 faith Exp $
*
*/
#include "dictd.h"
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#if HAVE_SYS_PARAM_H
# include <sys/param.h>
#endif
#ifndef MAXHOSTNAMELEN
#define MAXHOSTNAMELEN 64
#endif
#ifndef INADDR_NONE
#define INADDR_NONE (-1)
#endif
static char netHostname[MAXHOSTNAMELEN];
const char *net_hostname( void )
{
struct hostent *hostEntry;
static char *hostname = NULL;
if (!netHostname[0]) {
memset( netHostname, 0, sizeof(netHostname) );
gethostname( netHostname, sizeof(netHostname)-1 );
if ((hostEntry = gethostbyname(netHostname))) {
hostname = xstrdup(hostEntry->h_name);
} else {
hostname = xstrdup(netHostname);
}
}
return hostname;
}
int net_connect_tcp( const char *host, const char *service )
{
struct hostent *hostEntry;
struct servent *serviceEntry;
struct protoent *protocolEntry;
struct sockaddr_in ssin;
int s;
int hosts = 0;
char **current;
memset( &ssin, 0, sizeof(ssin) );
ssin.sin_family = AF_INET;
if ((hostEntry = gethostbyname(host))) {
++hosts;
} else if ((ssin.sin_addr.s_addr = inet_addr(host)) == INADDR_NONE)
return NET_NOHOST;
if ((serviceEntry = getservbyname(service, "tcp"))) {
ssin.sin_port = serviceEntry->s_port;
} else if (!(ssin.sin_port = htons(atoi(service))))
return NET_NOSERVICE;
if (!(protocolEntry = getprotobyname("tcp")))
return NET_NOPROTOCOL;
if (hosts) {
for (current = hostEntry->h_addr_list; *current; current++) {
memcpy( &ssin.sin_addr.s_addr, *current, hostEntry->h_length );
PRINTF(DBG_VERBOSE,
("Trying %s (%s)\n",host,inet_ntoa(ssin.sin_addr)));
if ((s = socket(PF_INET, SOCK_STREAM, protocolEntry->p_proto)) < 0)
err_fatal_errno( __FUNCTION__, "Can't open socket on port %d\n",
ntohs(ssin.sin_port) );
if (connect(s, (struct sockaddr *)&ssin, sizeof(ssin)) >= 0)
return s;
close(s);
}
} else {
if ((s = socket(PF_INET, SOCK_STREAM, protocolEntry->p_proto)) < 0)
err_fatal_errno( __FUNCTION__, "Can't open socket on port %d\n",
ntohs(ssin.sin_port) );
if (connect(s, (struct sockaddr *)&ssin, sizeof(ssin)) >= 0)
return s;
close(s);
}
return NET_NOCONNECT;
}
int net_open_tcp( const char *service, int queueLength )
{
struct servent *serviceEntry;
struct protoent *protocolEntry;
struct sockaddr_in ssin;
int s;
const int one = 1;
memset( &ssin, 0, sizeof(ssin) );
ssin.sin_family = AF_INET;
ssin.sin_addr.s_addr = INADDR_ANY;
if ((serviceEntry = getservbyname(service, "tcp"))) {
ssin.sin_port = serviceEntry->s_port;
} else if (!(ssin.sin_port = htons(atoi(service))))
err_fatal( __FUNCTION__, "Can't get \"%s\" service entry\n", service );
if (!(protocolEntry = getprotobyname("tcp")))
err_fatal( __FUNCTION__, "Can't get \"tcp\" protocol entry\n" );
if ((s = socket(PF_INET, SOCK_STREAM, protocolEntry->p_proto)) < 0)
err_fatal_errno( __FUNCTION__, "Can't open socket on port %d\n",
ntohs(ssin.sin_port) );
setsockopt( s, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one) );
if (bind(s, (struct sockaddr *)&ssin, sizeof(ssin)) < 0)
err_fatal_errno( __FUNCTION__, "Can't bind %s/tcp to port %d\n",
service, ntohs(ssin.sin_port) );
if (listen( s, queueLength ) < 0)
err_fatal_errno( __FUNCTION__, "Can't listen to %s/tcp on port %d\n",
service, ntohs(ssin.sin_port) );
return s;
}
void net_detach( void )
{
int i;
int fd;
switch (fork()) {
case -1: err_fatal_errno( __FUNCTION__, "Cannot fork\n" ); break;
case 0: break; /* child */
default: exit(0); /* parent */
}
/* The detach algorithm is a modification of that presented by Comer,
Douglas E. and Stevens, David L. INTERNETWORKING WITH TCP/IP, VOLUME
III: CLIENT-SERVER PROGRAMMING AND APPLICATIONS (BSD SOCKET VERSION).
Englewood Cliffs, New Jersey: Prentice Hall, 1993 (Chapter 27). */
for (i=getdtablesize()-1; i >= 0; --i) close(i); /* close everything */
#if !defined(__hpux__)
if ((fd = open("/dev/tty", O_RDWR)) >= 0) {
/* detach from controlling tty */
ioctl(fd, TIOCNOTTY, 0);
close(fd);
}
#endif
chdir("/"); /* cd to safe directory */
umask(0); /* set safe umask */
setpgid(0,getpid()); /* Get process group */
fd = open("/dev/null", O_RDWR); /* stdin */
dup(fd); /* stdout */
dup(fd); /* stderr */
}
int net_read( int s, char *buf, int maxlen )
{
int len;
int n = 0;
char c;
char *pt = buf;
*pt = '\0';
for (len = 0; len < maxlen && (n = read( s, &c, 1 )) > 0; /*void*/) {
switch (c) {
case '\n': *pt = '\0'; return len;
case '\r': break;
default: *pt++ = c; ++len; break;
}
}
*pt = '\0';
if (!n) return len ? len : EOF;
return n; /* error code */
}
int net_write( int s, const char *buf, int len )
{
int left = len;
int count;
while (left) {
if ((count = write(s, buf, left)) != left) {
if (count <= 0) return count; /* error code */
}
left -= count;
}
return len;
}
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