/* $Header: /afs/sipb.mit.edu/project/sipb-athena/repository/src/moira/update/config.c,v 1.3 1996/06/02 07:44:28 ghudson Exp $
 *
 * Routines to handle configuration file for Moira's update_server.
 * These routines must load the file into memory rather than parse
 * it each time as one of the things the server may do is chroot()
 * itself.
 *
 * (c) Copyright 1992 by the Massachusetts Institute of Technology.
 * For copying and distribution information, please see the file
 * <mit-copyright.h>.
 */

#include <mit-copyright.h>
#include <stdio.h>
#include <ctype.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <fcntl.h>
#include <moira.h>


#define CONFIG_FILE	"/etc/athena/moira.conf"

/* Variables currently supported:
 * chroot directory	daemon will run chrooted to this directory
 * user username	daemon will run with this user's uid
 * port portname	daemon will listen on this port number
 * nofork		server stays in foreground & logs to stdout
 * auth krbname		this user is authorized to connect
 * noclobber		will not overwrite existing files
 * noexec		will not execute instructions received
 */

static char *config_buf = NULL;
static char **config_keys, **config_values;


static init()
{
    int fd, count = 0;
    struct stat st;
    char *p, *start;

    /* Only execute once */
    if (config_buf) return(MR_SUCCESS);

    fd = open(CONFIG_FILE, O_RDONLY, 0);
    if (fd < 0) {
	config_buf = "";
	config_keys = (char **)malloc(sizeof(char *) * 2);
	config_keys[0] = config_keys[1] = NULL;
	return(MR_SUCCESS);
    }
    if (fstat(fd, &st) < 0) {
	return(MR_INTERNAL);
    }
    config_buf = (char *) malloc(st.st_size + 2);
    if (config_buf == NULL) {
	return(MR_NO_MEM);
    }
    if (read(fd, config_buf, st.st_size) < st.st_size) {
	free(config_buf);
	config_buf = NULL;
	return(MR_INTERNAL);
    }
    config_buf[st.st_size] = '\0';

    for (p = config_buf; *p; p++)
      if (*p == '\n') count++;
    count++;
    config_keys = (char **)malloc(count * sizeof(char *));
    config_values = (char **)malloc(count * sizeof(char *));
    if (config_keys == NULL || config_values == NULL) {
	free(config_buf);
	config_buf = NULL;
	return(MR_NO_MEM);
    }
    count = 0;
    for (p = start = config_buf; *p; p++) {
	if (*p != '\n')
	  continue;
	*p++ = '\0';
	config_keys[count++] = start;
	start = p;
	if (!*p) break;
    }
    config_keys[count] = NULL;
    for (count = 0; config_keys[count]; count++) {
	config_values[count] = "";
	for (p = config_keys[count]; *p; p++)
	  if (isspace(*p)) {
	      *p++ = '\0';
	      while (*p && isspace(*p)) p++;
	      config_values[count] = p;
	  }
    }
    return(MR_SUCCESS);
}


/* Given a key, lookup the associated value.  
 * Returns "" on a key without a value, NULL on a non-existant key.
 * If a key appears multiple times, successive calls will cycle through
 * the possible values.
 */

char *config_lookup(key)
char *key;
{
    static int i = 0;
    int start;

    if (init() != MR_SUCCESS)
      return(NULL);

    start = i++;
    if (config_keys[i] == NULL) i = 0;
    if (config_keys[i] == NULL) return(NULL);

    do {
      if (!strcasecmp(key, config_keys[i]))
	return(config_values[i]);
      if (config_keys[++i] == NULL)
	i = 0;
    } while (i != start);

    if (!strcasecmp(key, config_keys[i]))
      return(config_values[i]);

    return(NULL);
}