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freebsd/usr.sbin/ypserv/yp_main.c
Bill Paul 2dfb116a5a Add some extra checks to make sure that a child ypserv process doesn't
try to fork() a child of its own, which could result in several children
ypservs running at once. I'm still not sure exactly what leads to this
condition, but these fixes should stop it from causing trouble. A new
function, yp_fork() checks to see if the current process is already a
child of the parent ypserv, and returns failure (and logs an error message)
rather than spawning another child.
1999-04-29 20:24:00 +00:00

342 lines
7.8 KiB
C

/*
* Copyright (c) 1995
* Bill Paul <wpaul@ctr.columbia.edu>. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Bill Paul.
* 4. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY Bill Paul AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL Bill Paul OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
static const char rcsid[] =
"$Id: yp_main.c,v 1.19 1999/02/10 16:16:14 wpaul Exp $";
#endif /* not lint */
/*
* ypserv startup function.
* We need out own main() since we have to do some additional work
* that rpcgen won't do for us. Most of this file was generated using
* rpcgen.new, and later modified.
*/
#include "yp.h"
#include <err.h>
#include <errno.h>
#include <memory.h>
#include <stdio.h>
#include <signal.h>
#include <stdlib.h> /* getenv, exit */
#include <string.h> /* strcmp */
#include <syslog.h>
#include <unistd.h>
#include <rpc/pmap_clnt.h> /* for pmap_unset */
#include <sys/ttycom.h> /* TIOCNOTTY */
#ifdef __cplusplus
#include <sysent.h> /* getdtablesize, open */
#endif /* __cplusplus */
#include <sys/socket.h>
#include <netinet/in.h>
#include <sys/wait.h>
#include "yp_extern.h"
#include <rpc/rpc.h>
#ifndef SIG_PF
#define SIG_PF void(*)(int)
#endif
#define _RPCSVC_CLOSEDOWN 120
int _rpcpmstart; /* Started by a port monitor ? */
static int _rpcfdtype;
/* Whether Stream or Datagram ? */
/* States a server can be in wrt request */
#define _IDLE 0
#define _SERVED 1
#define _SERVING 2
extern void ypprog_1 __P((struct svc_req *, register SVCXPRT *));
extern void ypprog_2 __P((struct svc_req *, register SVCXPRT *));
extern int _rpc_dtablesize __P((void));
extern int _rpcsvcstate; /* Set when a request is serviced */
char *progname = "ypserv";
char *yp_dir = _PATH_YP;
/*int debug = 0;*/
int do_dns = 0;
int resfd;
static
void _msgout(char* msg)
{
if (debug) {
if (_rpcpmstart)
syslog(LOG_ERR, msg);
else
warnx("%s", msg);
} else
syslog(LOG_ERR, msg);
}
pid_t yp_pid;
static void
yp_svc_run()
{
#ifdef FD_SETSIZE
fd_set readfds;
#else
int readfds;
#endif /* def FD_SETSIZE */
extern int forked;
int fd_setsize = _rpc_dtablesize();
struct timeval timeout;
/* Establish the identity of the parent ypserv process. */
yp_pid = getpid();
for (;;) {
#ifdef FD_SETSIZE
readfds = svc_fdset;
#else
readfds = svc_fds;
#endif /* def FD_SETSIZE */
FD_SET(resfd, &readfds);
timeout.tv_sec = RESOLVER_TIMEOUT;
timeout.tv_usec = 0;
switch (select(fd_setsize, &readfds, NULL, NULL,
&timeout)) {
case -1:
if (errno == EINTR) {
continue;
}
warn("svc_run: - select failed");
return;
case 0:
if (getpid() == yp_pid)
yp_prune_dnsq();
break;
default:
if (getpid() == yp_pid) {
if (FD_ISSET(resfd, &readfds)) {
yp_run_dnsq();
FD_CLR(resfd, &readfds);
}
svc_getreqset(&readfds);
}
}
if (yp_pid != getpid())
_exit(0);
}
}
static void unregister()
{
(void) pmap_unset(YPPROG, YPVERS);
(void) pmap_unset(YPPROG, YPOLDVERS);
}
static void reaper(sig)
int sig;
{
int status;
int saved_errno;
saved_errno = errno;
if (sig == SIGHUP) {
load_securenets();
#ifdef DB_CACHE
yp_flush_all();
#endif
errno = saved_errno;
return;
}
if (sig == SIGCHLD) {
while (wait3(&status, WNOHANG, NULL) > 0)
children--;
} else {
unregister();
exit(0);
}
errno = saved_errno;
return;
}
static void usage()
{
fprintf(stderr, "usage: ypserv [-h] [-d] [-n] [-p path]\n");
exit(1);
}
static void
closedown(int sig)
{
if (_rpcsvcstate == _IDLE) {
extern fd_set svc_fdset;
static int size;
int i, openfd;
if (_rpcfdtype == SOCK_DGRAM) {
unregister();
exit(0);
}
if (size == 0) {
size = getdtablesize();
}
for (i = 0, openfd = 0; i < size && openfd < 2; i++)
if (FD_ISSET(i, &svc_fdset))
openfd++;
if (openfd <= 1) {
unregister();
exit(0);
}
}
if (_rpcsvcstate == _SERVED)
_rpcsvcstate = _IDLE;
(void) signal(SIGALRM, (SIG_PF) closedown);
(void) alarm(_RPCSVC_CLOSEDOWN/2);
}
int
main(argc, argv)
int argc;
char *argv[];
{
register SVCXPRT *transp = NULL;
int sock;
int proto = 0;
struct sockaddr_in saddr;
int asize = sizeof (saddr);
int ch;
while ((ch = getopt(argc, argv, "hdnp:")) != -1) {
switch(ch) {
case 'd':
debug = ypdb_debug = 1;
break;
case 'n':
do_dns = 1;
break;
case 'p':
yp_dir = optarg;
break;
case 'h':
default:
usage();
}
}
load_securenets();
yp_init_resolver();
#ifdef DB_CACHE
yp_init_dbs();
#endif
if (getsockname(0, (struct sockaddr *)&saddr, &asize) == 0) {
int ssize = sizeof (int);
if (saddr.sin_family != AF_INET)
exit(1);
if (getsockopt(0, SOL_SOCKET, SO_TYPE,
(char *)&_rpcfdtype, &ssize) == -1)
exit(1);
sock = 0;
_rpcpmstart = 1;
proto = 0;
openlog("ypserv", LOG_PID, LOG_DAEMON);
} else {
if (!debug) {
if (daemon(0,0)) {
err(1,"cannot fork");
}
openlog("ypserv", LOG_PID, LOG_DAEMON);
}
sock = RPC_ANYSOCK;
(void) pmap_unset(YPPROG, YPVERS);
(void) pmap_unset(YPPROG, 1);
}
if ((_rpcfdtype == 0) || (_rpcfdtype == SOCK_DGRAM)) {
transp = svcudp_create(sock);
if (transp == NULL) {
_msgout("cannot create udp service");
exit(1);
}
if (!_rpcpmstart)
proto = IPPROTO_UDP;
if (!svc_register(transp, YPPROG, YPOLDVERS, ypprog_1, proto)) {
_msgout("unable to register (YPPROG, YPOLDVERS, udp)");
exit(1);
}
if (!svc_register(transp, YPPROG, YPVERS, ypprog_2, proto)) {
_msgout("unable to register (YPPROG, YPVERS, udp)");
exit(1);
}
}
if ((_rpcfdtype == 0) || (_rpcfdtype == SOCK_STREAM)) {
transp = svctcp_create(sock, 0, 0);
if (transp == NULL) {
_msgout("cannot create tcp service");
exit(1);
}
if (!_rpcpmstart)
proto = IPPROTO_TCP;
if (!svc_register(transp, YPPROG, YPOLDVERS, ypprog_1, proto)) {
_msgout("unable to register (YPPROG, YPOLDVERS, tcp)");
exit(1);
}
if (!svc_register(transp, YPPROG, YPVERS, ypprog_2, proto)) {
_msgout("unable to register (YPPROG, YPVERS, tcp)");
exit(1);
}
}
if (transp == (SVCXPRT *)NULL) {
_msgout("could not create a handle");
exit(1);
}
if (_rpcpmstart) {
(void) signal(SIGALRM, (SIG_PF) closedown);
(void) alarm(_RPCSVC_CLOSEDOWN/2);
}
/*
* Make sure SIGPIPE doesn't blow us away while servicing TCP
* connections.
*/
(void) signal(SIGPIPE, SIG_IGN);
(void) signal(SIGCHLD, (SIG_PF) reaper);
(void) signal(SIGTERM, (SIG_PF) reaper);
(void) signal(SIGINT, (SIG_PF) reaper);
(void) signal(SIGHUP, (SIG_PF) reaper);
yp_svc_run();
_msgout("svc_run returned");
exit(1);
/* NOTREACHED */
}