/*	$OpenBSD: admin_server.c,v 1.5 1999/05/23 17:19:24 aaron Exp $	*/
/* $KTH: admin_server.c,v 1.42 1997/12/04 19:31:39 assar Exp $ */

/* 
 * Copyright (C) 1989 by the Massachusetts Institute of Technology
 *
 * Export of this software from the United States of America is assumed
 * to require a specific license from the United States Government.
 * It is the responsibility of any person or organization contemplating
 * export to obtain such a license before exporting.
 *
 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
 * distribute this software and its documentation for any purpose and
 * without fee is hereby granted, provided that the above copyright
 * notice appear in all copies and that both that copyright notice and
 * this permission notice appear in supporting documentation, and that
 * the name of M.I.T. not be used in advertising or publicity pertaining
 * to distribution of the software without specific, written prior
 * permission.  M.I.T. makes no representations about the suitability of
 * this software for any purpose.  It is provided "as is" without express
 * or implied warranty.
 *
 */

/*
 * Top-level loop of the kerberos Administration server
 */

/*
  admin_server.c
  this holds the main loop and initialization and cleanup code for the server
*/

#include "kadm_locl.h"

/* Almost all procs and such need this, so it is global */
admin_params prm;		/* The command line parameters struct */

/* GLOBAL */
char *acldir = DEFAULT_ACL_DIR;
static char krbrlm[REALM_SZ];

static unsigned pidarraysize = 0;
static int *pidarray = (int *)0;

static int exit_now = 0;

void
doexit(int sig)
{
    exit_now = 1;
    return;
}
   
void
do_child(int sig)
{
    int pid;
    int i, j;

    int status;

    pid = wait(&status);

    /* Reinstall signal handlers for SysV. Must be done *after* wait */
    signal(SIGCHLD, do_child);

    for (i = 0; i < pidarraysize; i++)
	if (pidarray[i] == pid) {
	    /* found it */
	    for (j = i; j < pidarraysize-1; j++)
		/* copy others down */
		pidarray[j] = pidarray[j+1];
	    pidarraysize--;
	    if ((WIFEXITED(status) && WEXITSTATUS(status) != 0)
		|| WIFSIGNALED(status))
	      krb_log("child %d: termsig %d, retcode %d", pid,
		  WTERMSIG(status), WEXITSTATUS(status));
	    return;
	}
    krb_log("child %d not in list: termsig %d, retcode %d", pid,
	WTERMSIG(status), WEXITSTATUS(status));
}

static void
kill_children(void)
{
    int i;

    for (i = 0; i < pidarraysize; i++) {
	kill(pidarray[i], SIGINT);
	krb_log("killing child %d", pidarray[i]);
    }
}

/* close the system log file */
static void
close_syslog(void)
{
   krb_log("Shutting down admin server");
}

static void
byebye(void)			/* say goodnight gracie */
{
   printf("Admin Server (kadm server) has completed operation.\n");
}

static void
clear_secrets(void)
{
    memset(server_parm.master_key, 0, sizeof(server_parm.master_key));
    memset(server_parm.master_key_schedule, 0,
	  sizeof(server_parm.master_key_schedule));
    server_parm.master_key_version = 0L;
}

#ifdef DEBUG
#define cleanexit(code) {kerb_fini(); return;}
#endif

#ifndef DEBUG
static void
cleanexit(int val)
{
    kerb_fini();
    clear_secrets();
    exit(val);
}
#endif

static void
process_client(int fd, struct sockaddr_in *who)
{
    u_char *dat;
    int dat_len;
    u_short dlen;
    int retval;
    int on = 1;
    Principal service;
    des_cblock skey;
    int more;
    int status;

    if (setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, (void *)&on, sizeof(on)) < 0)
	krb_log("setsockopt keepalive: %d",errno);

    server_parm.recv_addr = *who;

    if (kerb_init()) {			/* Open as client */
	krb_log("can't open krb db");
	cleanexit(1);
    }
    /* need to set service key to changepw.KRB_MASTER */

    status = kerb_get_principal(server_parm.sname, server_parm.sinst, &service,
			    1, &more);
    if (status == -1) {
      /* db locked */
      int32_t retcode = KADM_DB_INUSE;
      char *pdat;
      
      dat_len = KADM_VERSIZE + sizeof(retcode);
      dat = (u_char *) malloc((unsigned)dat_len);
      pdat = (char *) dat;
      retcode = htonl((u_int32_t) KADM_DB_INUSE);
      strncpy(pdat, KADM_ULOSE, KADM_VERSIZE);
      memcpy(pdat+KADM_VERSIZE, &retcode, sizeof(retcode));
      goto out;
    } else if (!status) {
      krb_log("no service %s.%s",server_parm.sname, server_parm.sinst);
      cleanexit(2);
    }

    copy_to_key(&service.key_low, &service.key_high, skey);
    memset(&service, 0, sizeof(service));
    kdb_encrypt_key (&skey, &skey, &server_parm.master_key,
		     server_parm.master_key_schedule, DES_DECRYPT);
    krb_set_key(skey, 0); /* if error, will show up when
					    rd_req fails */
    memset(skey, 0, sizeof(skey));

    while (1) {
	if ((retval = krb_net_read(fd, &dlen, sizeof(u_short))) !=
	    sizeof(u_short)) {
	    if (retval < 0)
		krb_log("dlen read: %s",error_message(errno));
	    else if (retval)
		krb_log("short dlen read: %d",retval);
	    close(fd);
	    cleanexit(retval ? 3 : 0);
	}
	if (exit_now) {
	    cleanexit(0);
	}
	dat_len = ntohs(dlen);
	dat = (u_char *) malloc(dat_len);
	if (!dat) {
	    krb_log("malloc: No memory");
	    close(fd);
	    cleanexit(4);
	}
	if ((retval = krb_net_read(fd, dat, dat_len)) != dat_len) {
	    if (retval < 0)
		krb_log("data read: %s",error_message(errno));
	    else
		krb_log("short read: %d vs. %d", dat_len, retval);
	    close(fd);
	    cleanexit(5);
	}
    	if (exit_now) {
	    cleanexit(0);
	}
	if ((retval = kadm_ser_in(&dat,&dat_len)) != KADM_SUCCESS)
	    krb_log("processing request: %s", error_message(retval));
    
	/* kadm_ser_in did the processing and returned stuff in
	   dat & dat_len , return the appropriate data */
    
    out:
	dlen = htons(dat_len);
    
	if (krb_net_write(fd, &dlen, sizeof(u_short)) < 0) {
	    krb_log("writing dlen to client: %s",error_message(errno));
	    close(fd);
	    cleanexit(6);
	}
    
	if (krb_net_write(fd, dat, dat_len) < 0) {
	    krb_log("writing to client: %s", error_message(errno));
	    close(fd);
	    cleanexit(7);
	}
	free(dat);
    }
    /*NOTREACHED*/
}

/*
kadm_listen
listen on the admin servers port for a request
*/
static int
kadm_listen(void)
{
    int found;
    int admin_fd;
    int peer_fd;
    fd_set mask, readfds;
    struct sockaddr_in peer;
    int addrlen;
    int pid;
    int *temp;

    signal(SIGINT, doexit);
    signal(SIGTERM, doexit);
    signal(SIGHUP, doexit);
    signal(SIGQUIT, doexit);
    signal(SIGPIPE, SIG_IGN); /* get errors on write() */
    signal(SIGALRM, doexit);
    signal(SIGCHLD, do_child);
    if (setsid() < 0)
        krb_log("setsid() failed");

    if ((admin_fd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
	return KADM_NO_SOCK;
    {
	int one=1;
	setsockopt(admin_fd, SOL_SOCKET, SO_REUSEADDR, (void *)&one,
		   sizeof(one));
    }
    if (bind(admin_fd, (struct sockaddr *)&server_parm.admin_addr,
	     sizeof(struct sockaddr_in)) < 0)
	return KADM_NO_BIND;
    listen(admin_fd, 1);
    FD_ZERO(&mask);
    FD_SET(admin_fd, &mask);

    for (;;) {				/* loop nearly forever */
	if (exit_now) {
	    clear_secrets();
	    kill_children();
	    return(0);
	}
	readfds = mask;
	if ((found = select(admin_fd+1, &readfds, 0,
			    0, (struct timeval *)0)) == 0)
	    continue;			/* no things read */
	if (found < 0) {
	    if (errno != EINTR)
		krb_log("select: %s",error_message(errno));
	    continue;
	}      
	if (FD_ISSET(admin_fd, &readfds)) {
	    /* accept the conn */
	    addrlen = sizeof(peer);
	    if ((peer_fd = accept(admin_fd, (struct sockaddr *)&peer,
				  &addrlen)) < 0) {
		krb_log("accept: %s",error_message(errno));
		continue;
	    }
#ifndef DEBUG
	    /* grow the pidarray before forking, so we can catch the errors */
	    temp = realloc(pidarray, ++pidarraysize);
	    if (temp == NULL) {
	        krb_log("realloc: %s", error_message(errno));
		close(peer_fd);
	        continue;
	    }
	    pidarray = temp;
	    /* if you want a sep daemon for each server */
	    if ((pid = fork())) {
		/* parent */
		if (pid < 0) {
		    krb_log("fork: %s",error_message(errno));
		    close(peer_fd);
		    continue;
		}
		/* fork succeded: keep tabs on child */
		close(peer_fd);
		pidarray[pidarraysize-1] = pid;
	    } else {
		/* child */
		close(admin_fd);
#endif /* DEBUG */
		/*
		 * If we are multihomed we need to figure out which
		 * local address that is used this time since it is
		 * used in "direction" comparison.
		 */
		getsockname(peer_fd,
			    (struct sockaddr *)&server_parm.admin_addr,
			    &addrlen);
		/* do stuff */
		process_client (peer_fd, &peer);
#ifndef DEBUG
	    }
#endif
	} else {
	    krb_log("something else woke me up!");
	    return(0);
	}
    }
    /*NOTREACHED*/
}

/*
** Main does the logical thing, it sets up the database and RPC interface,
**  as well as handling the creation and maintenance of the syslog file...
*/
int
main(int argc, char **argv)		/* admin_server main routine */
{
    int errval;
    int c;

    umask(077);		/* Create protected files */

    /* initialize the admin_params structure */
    prm.sysfile = KADM_SYSLOG;		/* default file name */
    prm.inter = 0;

    memset(krbrlm, 0, sizeof(krbrlm));

    while ((c = getopt(argc, argv, "f:hmnd:a:r:")) != -1)
	switch(c) {
	case 'f':			/* Syslog file name change */
	    prm.sysfile = optarg;
	    break;
	case 'n':
	    prm.inter = 0;
	    break;
	case 'm':
	    prm.inter = 1;
	    break;
	case 'a':			/* new acl directory */
	    acldir = optarg;
	    break;
	case 'd':
	    /* put code to deal with alt database place */
	    if ((errval = kerb_db_set_name(optarg)))
		errx (1, "opening database %s: %s",
		      optarg, error_message(errval));
	    break;
	case 'r':
	    strncpy(krbrlm, optarg, sizeof(krbrlm) - 1);
	    krbrlm[sizeof(krbrlm) - 1] = '\0';
	    break;
	case 'h':			/* get help on using admin_server */
	default:
	    errx(1, "Usage: kadmind [-h] [-n] [-m] [-r realm] [-d dbname] [-f filename] [-a acldir]");
	}

    if (krbrlm[0] == 0)
	if (krb_get_lrealm(krbrlm, 0) != KSUCCESS)
	    errx (1, "Unable to get local realm.  Fix krb.conf or use -r.");

    printf("KADM Server %s initializing\n",KADM_VERSTR);
    printf("Please do not use 'kill -9' to kill this job, use a\n");
    printf("regular kill instead\n\n");

    kset_logfile(prm.sysfile);
    krb_log("Admin server starting");

    kerb_db_set_lockmode(KERB_DBL_NONBLOCKING);
    errval = kerb_init();		/* Open the Kerberos database */
    if (errval) {
	warnx ("error: kerb_init() failed");
	close_syslog();
	byebye();
    }
    /* set up the server_parm struct */
    if ((errval = kadm_ser_init(prm.inter, krbrlm))==KADM_SUCCESS) {
	kerb_fini();			/* Close the Kerberos database--
					   will re-open later */
	errval = kadm_listen();		/* listen for calls to server from
					   clients */
    }
    if (errval != KADM_SUCCESS) {
	warnx("error:  %s",error_message(errval));
	kerb_fini();			/* Close if error */
    }
    close_syslog();			/* Close syslog file, print
					   closing note */
    byebye();				/* Say bye bye on the terminal
					   in use */
    exit(1);
}					/* procedure main */