* Copyright (c) 1988, 1992 The University of Utah and the Center

/* $NetBSD: rbootd.c,v 1.24 2017/05/04 16:26:09 sevan Exp $ */

/*
* Copyright (c) 1988, 1992 The University of Utah and the Center
* for Software Science (CSS).
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* the Center for Software Science of the University of Utah Computer
* Science Department. CSS requests users of this software to return
* to [email protected] any improvements that they make and grant
* CSS redistribution rights.
*
* 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. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 THE REGENTS 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.
*
* from: @(#)rbootd.c 8.1 (Berkeley) 6/4/93
*
* From: Utah Hdr: rbootd.c 3.1 92/07/06
* Author: Jeff Forys, University of Utah CSS
*/

#include <sys/cdefs.h>
#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1992, 1993\
The Regents of the University of California. All rights reserved.");
#endif /* not lint */

#ifndef lint
#if 0
static char sccsid[] = "@(#)rbootd.c 8.1 (Berkeley) 6/4/93";
#else
__RCSID("$NetBSD: rbootd.c,v 1.24 2017/05/04 16:26:09 sevan Exp $");
#endif
#endif /* not lint */

#include <sys/param.h>
#include <sys/time.h>
#include <poll.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>
#include <util.h>
#include "defs.h"

int
main(int argc, char *argv[])
{
int c, fd, omask;
struct pollfd set[1];

/*
* Close any open file descriptors.
* Temporarily leave stdin & stdout open for `-d',
* and stderr open for any pre-syslog error messages.
*/
{
int i, nfds = getdtablesize();

for (i = 0; i < nfds; i++)
if (i != STDIN_FILENO && i != STDOUT_FILENO &&
i != STDERR_FILENO)
(void) close(i);
}

/*
* Parse any arguments.
*/
while ((c = getopt(argc, argv, "adi:")) != -1)
switch(c) {
case 'a':
BootAny++;
break;
case 'd':
DebugFlg++;
break;
case 'i':
IntfName = optarg;
break;
}
for (; optind < argc; optind++) {
if (ConfigFile == NULL)
ConfigFile = argv[optind];
else {
warnx("too many config files (`%s' ignored)",
argv[optind]);
}
}

if (ConfigFile == NULL) /* use default config file */
ConfigFile = DfltConfig;

if (DebugFlg) {
DbgFp = stdout; /* output to stdout */

(void) signal(SIGUSR1, SIG_IGN); /* dont muck w/DbgFp */
(void) signal(SIGUSR2, SIG_IGN);
(void) fclose(stderr); /* finished with it */
} else {
if (daemon(0, 0))
err(1, "can't detach from terminal");
pidfile(NULL);

(void) signal(SIGUSR1, DebugOn);
(void) signal(SIGUSR2, DebugOff);
}

openlog("rbootd", LOG_PID, LOG_DAEMON);

/*
* If no interface was specified, get one now.
*
* This is convoluted because we want to get the default interface
* name for the syslog("restarted") message. If BpfGetIntfName()
* runs into an error, it will return a syslog-able error message
* (in `errmsg') which will be displayed here.
*/
if (IntfName == NULL) {
char *errmsg;

if ((IntfName = BpfGetIntfName(&errmsg)) == NULL) {
/* backslash to avoid trigraph ??) */
syslog(LOG_NOTICE, "restarted (?\?)");
syslog(LOG_ERR, "%s", errmsg);
Exit(0);
}
}

syslog(LOG_NOTICE, "restarted (%s)", IntfName);

(void) signal(SIGHUP, ReConfig);
(void) signal(SIGINT, Exit);
(void) signal(SIGTERM, Exit);

/*
* Grab our host name and pid.
*/
if (gethostname(MyHost, sizeof MyHost) < 0) {
syslog(LOG_ERR, "gethostname: %m");
Exit(0);
}
MyHost[sizeof(MyHost) - 1] = '\0';

/*
* All boot files are relative to the boot directory, we might
* as well chdir() there to make life easier.
*/
if (chdir(BootDir) < 0) {
syslog(LOG_ERR, "chdir: %m (%s)", BootDir);
Exit(0);
}

/*
* Initial configuration.
*/
omask = sigblock(sigmask(SIGHUP)); /* prevent reconfig's */
if (GetBootFiles() == 0) /* get list of boot files */
Exit(0);
if (ParseConfig() == 0) /* parse config file */
Exit(0);

/*
* Open and initialize a BPF device for the appropriate interface.
* If an error is encountered, a message is displayed and Exit()
* is called.
*/
fd = BpfOpen();

(void) sigsetmask(omask); /* allow reconfig's */

/*
* Main loop: receive a packet, determine where it came from,
* and if we service this host, call routine to handle request.
*/
set[0].fd = fd;
set[0].events = POLLIN;
for (;;) {
int nsel;

nsel = poll(set, 1, RmpConns ? RMP_TIMEOUT * 1000 : INFTIM);

if (nsel < 0) {
if (errno == EINTR)
continue;
syslog(LOG_ERR, "poll: %m");
Exit(0);
} else if (nsel == 0) { /* timeout */
DoTimeout(); /* clear stale conns */
continue;
}

if (set[0].revents & POLLIN) {
RMPCONN rconn;
CLIENT *client;
int doread = 1;

while (BpfRead(&rconn, doread)) {
doread = 0;

if (DbgFp != NULL) /* display packet */
DispPkt(&rconn,DIR_RCVD);

omask = sigblock(sigmask(SIGHUP));

/*
* If we do not restrict service, set the
* client to NULL (ProcessPacket() handles
* this). Otherwise, check that we can
* service this host; if not, log a message
* and ignore the packet.
*/
if (BootAny) {
client = NULL;
} else if ((client=FindClient(&rconn))==NULL) {
syslog(LOG_INFO,
"%s: boot packet ignored",
EnetStr(&rconn));
(void) sigsetmask(omask);
continue;
}

ProcessPacket(&rconn,client);

(void) sigsetmask(omask);
}
}
}
}

/*
** DoTimeout -- Free any connections that have timed out.
**
** Parameters:
** None.
**
** Returns:
** Nothing.
**
** Side Effects:
** - Timed out connections in `RmpConns' will be freed.
*/
void
DoTimeout(void)
{
RMPCONN *rtmp;
struct timeval now;

(void) gettimeofday(&now, (struct timezone *)0);

/*
* For each active connection, if RMP_TIMEOUT seconds have passed
* since the last packet was sent, delete the connection.
*/
for (rtmp = RmpConns; rtmp != NULL; rtmp = rtmp->next)
if ((rtmp->tstamp.tv_sec + RMP_TIMEOUT) < now.tv_sec) {
syslog(LOG_WARNING, "%s: connection timed out (%u)",
EnetStr(rtmp), rtmp->rmp.r_type);
RemoveConn(rtmp);
}
}

/*
** FindClient -- Find client associated with a packet.
**
** Parameters:
** rconn - the new packet.
**
** Returns:
** Pointer to client info if found, NULL otherwise.
**
** Side Effects:
** None.
**
** Warnings:
** - This routine must be called with SIGHUP blocked since
** a reconfigure can invalidate the information returned.
*/

CLIENT *
FindClient(RMPCONN *rconn)
{
CLIENT *ctmp;

for (ctmp = Clients; ctmp != NULL; ctmp = ctmp->next)
if (memcmp((char *)&rconn->rmp.hp_hdr.saddr[0],
(char *)&ctmp->addr[0], RMP_ADDRLEN) == 0)
break;

return(ctmp);
}

/*
** Exit -- Log an error message and exit.
**
** Parameters:
** sig - caught signal (or zero if not dying on a signal).
**
** Returns:
** Does not return.
**
** Side Effects:
** - This process ceases to exist.
*/
void
Exit(int sig)
{
if (sig > 0)
syslog(LOG_ERR, "going down on signal %d", sig);
else
syslog(LOG_ERR, "going down with fatal error");
BpfClose();
exit(1);
}

/*
** ReConfig -- Get new list of boot files and reread config files.
**
** Parameters:
** None.
**
** Returns:
** Nothing.
**
** Side Effects:
** - All active connections are dropped.
** - List of boot-able files is changed.
** - List of clients is changed.
**
** Warnings:
** - This routine must be called with SIGHUP blocked.
*/
void
ReConfig(int signo)
{
syslog(LOG_NOTICE, "reconfiguring boot server");

FreeConns();

if (GetBootFiles() == 0)
Exit(0);

if (ParseConfig() == 0)
Exit(0);
}

/*
** DebugOff -- Turn off debugging.
**
** Parameters:
** None.
**
** Returns:
** Nothing.
**
** Side Effects:
** - Debug file is closed.
*/
void
DebugOff(int signo)
{
if (DbgFp != NULL)
(void) fclose(DbgFp);

DbgFp = NULL;
}

/*
** DebugOn -- Turn on debugging.
**
** Parameters:
** None.
**
** Returns:
** Nothing.
**
** Side Effects:
** - Debug file is opened/truncated if not already opened,
** otherwise do nothing.
*/
void
DebugOn(int signo)
{
if (DbgFp == NULL) {
if ((DbgFp = fopen(DbgFile, "w")) == NULL)
syslog(LOG_ERR, "can't open debug file (%s)", DbgFile);
}
}