ntp_config.c

网络时间协议NTP 源码 版本v4.2.0b 该源码用于linux平台下

	info_auth_keyid = req_keyid;
#endif /* !defined(VMS) && !defined(SYS_VXWORKS) */

	if (res_fp != NULL) {
		if (call_resolver) {
			/*
			 * Need name resolution
			 */
			do_resolve_internal();
		}
	}
}


#ifdef HAVE_NETINFO

/* 
 * get_netinfo_config - find the nearest NetInfo domain with an ntp
 * configuration and initialize the configuration state.
 */
static struct netinfo_config_state *
get_netinfo_config()
{
	ni_status status;
	void *domain;
	ni_id config_dir;
       	struct netinfo_config_state *config;

	if (ni_open(NULL, ".", &domain) != NI_OK) return NULL;

	while ((status = ni_pathsearch(domain, &config_dir, NETINFO_CONFIG_DIR)) == NI_NODIR) {
		void *next_domain;
		if (ni_open(domain, "..", &next_domain) != NI_OK) {
			ni_free(next_domain);
			break;
		}
		ni_free(domain);
		domain = next_domain;
	}
	if (status != NI_OK) {
		ni_free(domain);
		return NULL;
	}

       	config = (struct netinfo_config_state *)malloc(sizeof(struct netinfo_config_state));
       	config->domain = domain;
       	config->config_dir = config_dir;
       	config->prop_index = 0;
       	config->val_index = 0;
       	config->val_list = NULL;

	return config;
}



/*
 * free_netinfo_config - release NetInfo configuration state
 */
static void
free_netinfo_config(struct netinfo_config_state *config)
{
	ni_free(config->domain);
	free(config);
}



/*
 * gettokens_netinfo - return tokens from NetInfo
 */
static int
gettokens_netinfo (
	struct netinfo_config_state *config,
	char **tokenlist,
	int *ntokens
	)
{
	int prop_index = config->prop_index;
	int val_index = config->val_index;
	char **val_list = config->val_list;

	/*
	 * Iterate through each keyword and look for a property that matches it.
	 */
	again:
	if (!val_list) {
	       	for (; prop_index < (sizeof(keywords)/sizeof(keywords[0])); prop_index++)
	       	{
		       	ni_namelist namelist;
			struct keyword current_prop = keywords[prop_index];

			/*
			 * For each value associated in the property, we're going to return
			 * a separate line. We squirrel away the values in the config state
			 * so the next time through, we don't need to do this lookup.
			 */
		       	NI_INIT(&namelist);
	       		if (ni_lookupprop(config->domain, &config->config_dir, current_prop.text, &namelist) == NI_OK) {
				ni_index index;

				/* Found the property, but it has no values */
				if (namelist.ni_namelist_len == 0) continue;

				if (! (val_list = config->val_list = (char**)malloc(sizeof(char*) * (namelist.ni_namelist_len + 1))))
					{ msyslog(LOG_ERR, "out of memory while configuring"); break; }

				for (index = 0; index < namelist.ni_namelist_len; index++) {
					char *value = namelist.ni_namelist_val[index];

					if (! (val_list[index] = (char*)malloc(strlen(value)+1)))
						{ msyslog(LOG_ERR, "out of memory while configuring"); break; }

					strcpy(val_list[index], value);
				}
				val_list[index] = NULL;

				break;
			}
			ni_namelist_free(&namelist);
		}
		config->prop_index = prop_index;
	}

	/* No list; we're done here. */
       	if (!val_list) return CONFIG_UNKNOWN;

	/*
	 * We have a list of values for the current property.
	 * Iterate through them and return each in order.
	 */
	if (val_list[val_index])
	{
		int ntok = 1;
		int quoted = 0;
		char *tokens = val_list[val_index];

		msyslog(LOG_INFO, "%s %s", keywords[prop_index].text, val_list[val_index]);

		(const char*)tokenlist[0] = keywords[prop_index].text;
		for (ntok = 1; ntok < MAXTOKENS; ntok++) {
			tokenlist[ntok] = tokens;
			while (!ISEOL(*tokens) && (!ISSPACE(*tokens) || quoted))
				quoted ^= (*tokens++ == '"');

			if (ISEOL(*tokens)) {
				*tokens = '\0';
				break;
			} else {		/* must be space */
				*tokens++ = '\0';
				while (ISSPACE(*tokens)) tokens++;
				if (ISEOL(*tokens)) break;
			}
		}

		if (ntok == MAXTOKENS) {
			/* HMS: chomp it to lose the EOL? */
			msyslog(LOG_ERR,
			    "gettokens_netinfo: too many tokens.  Ignoring: %s",
			    tokens);
		} else {
			*ntokens = ntok + 1;
		}

		config->val_index++;	/* HMS: Should this be in the 'else'? */

		return keywords[prop_index].keytype;
	}

	/* We're done with the current property. */
	prop_index = ++config->prop_index;

	/* Free val_list and reset counters. */
	for (val_index = 0; val_list[val_index]; val_index++)
		free(val_list[val_index]);
       	free(val_list);	val_list = config->val_list = NULL; val_index = config->val_index = 0;

	goto again;
}

#endif /* HAVE_NETINFO */


/*
 * gettokens - read a line and return tokens
 */
static int
gettokens (
	FILE *fp,
	char *line,
	char **tokenlist,
	int *ntokens
	)
{
	register char *cp;
	register int ntok;
	register int quoted = 0;

	/*
	 * Find start of first token
	 */
	again:
	while ((cp = fgets(line, MAXLINE, fp)) != NULL) {
		cp = line;
		while (ISSPACE(*cp))
			cp++;
		if (!ISEOL(*cp))
			break;
	}
	if (cp == NULL) {
		*ntokens = 0;
		return CONFIG_UNKNOWN;	/* hack.  Is recognized as EOF */
	}

	/*
	 * Now separate out the tokens
	 */
	for (ntok = 0; ntok < MAXTOKENS; ntok++) {
		tokenlist[ntok] = cp;
		while (!ISEOL(*cp) && (!ISSPACE(*cp) || quoted))
			quoted ^= (*cp++ == '"');

		if (ISEOL(*cp)) {
			*cp = '\0';
			break;
		} else {		/* must be space */
			*cp++ = '\0';
			while (ISSPACE(*cp))
				cp++;
			if (ISEOL(*cp))
				break;
		}
	}

     /* Heiko: Remove leading and trailing quotes around tokens */
     {
            int i,j = 0;
	    
		
			for (i = 0; i < ntok; i++) {	    
					/* Now check if the first char is a quote and remove that */
					if ( tokenlist[ntok][0] == '"' )
							tokenlist[ntok]++;

					/* Now check the last char ... */
					j = strlen(tokenlist[ntok])-1;
					if ( tokenlist[ntok][j] == '"' )
							tokenlist[ntok][j] = '\0';
			}
							
    }

	if (ntok == MAXTOKENS) {
		--ntok;
		/* HMS: chomp it to lose the EOL? */
		msyslog(LOG_ERR,
		    "gettokens: too many tokens on the line. Ignoring %s",
		    cp);
	} else {
		/*
		 * Return the match
		 */
		*ntokens = ntok + 1;
		ntok = matchkey(tokenlist[0], keywords, 1);
		if (ntok == CONFIG_UNKNOWN)
			goto again;
	}

	return ntok;
}



/*
 * matchkey - match a keyword to a list
 */
static int
matchkey(
	register char *word,
	register struct keyword *keys,
	int complain
	)
{
	for (;;) {
		if (keys->keytype == CONFIG_UNKNOWN) {
			if (complain)
				msyslog(LOG_ERR,
				    "configure: keyword \"%s\" unknown, line ignored",
				    word);
			return CONFIG_UNKNOWN;
		}
		if (STRSAME(word, keys->text))
			return keys->keytype;
		keys++;
	}
}


/*
 * getnetnum - return a net number (this is crude, but careful)
 */
static int
getnetnum(
	const char *num,
	struct sockaddr_storage *addr,
	int complain,
	enum gnn_type a_type
	)
{
	struct addrinfo hints;
	struct addrinfo *ptr;
	int retval;

	/* Get host address. Looking for UDP datagram connection */
 	memset(&hints, 0, sizeof (hints));
 	if (addr->ss_family == AF_INET || addr->ss_family == AF_INET6)
	    hints.ai_family = addr->ss_family;
	else
	    hints.ai_family = AF_UNSPEC;
	/*
	 * If we don't have an IPv6 stack, just look up IPv4 addresses
	 */
	if (isc_net_probeipv6() != ISC_R_SUCCESS)
		hints.ai_family = AF_INET;

	hints.ai_socktype = SOCK_DGRAM;
#ifdef DEBUG
		if (debug > 3)
			printf("getaddrinfo %s\n", num);
#endif
	retval = getaddrinfo(num, "ntp", &hints, &ptr);
	if (retval != 0 ||
	   (ptr->ai_family == AF_INET6 && isc_net_probeipv6() != ISC_R_SUCCESS)) {
		if (complain)
			msyslog(LOG_ERR,
				"getaddrinfo: \"%s\" invalid host address, ignored",
				num);
#ifdef DEBUG
		if (debug > 0)
			printf(
				"getaddrinfo: \"%s\" invalid host address%s.\n",
				num, (complain)
				? ", ignored"
				: "");
#endif
		if (retval == 0 && 
		    ptr->ai_family == AF_INET6 && 
		    isc_net_probeipv6() != ISC_R_SUCCESS) 
		{
			return -1;
		}
		else {
			return 0;
		}
	}

	memcpy(addr, ptr->ai_addr, ptr->ai_addrlen);
#ifdef DEBUG
	if (debug > 1)
		printf("getnetnum given %s, got %s \n",
		   num, stoa(addr));
#endif
        freeaddrinfo(ptr);
	return 1;
}


#if !defined(VMS) && !defined(SYS_WINNT)
/*
 * catchchild - receive the resolver's exit status
 */
static RETSIGTYPE
catchchild(
	int sig
	)
{
	/*
	 * We only start up one child, and if we're here
	 * it should have already exited.  Hence the following
	 * shouldn't hang.  If it does, please tell me.
	 */
#if !defined (SYS_WINNT) && !defined(SYS_VXWORKS)
	(void) wait(0);
#endif /* SYS_WINNT  && VXWORKS*/
}
#endif /* VMS */


/*
 * save_resolve - save configuration info into a file for later name resolution
 */
static void
save_resolve(
	char *name,
	int mode,
	int version,
	int minpoll,
	int maxpoll,
	u_int flags,
	int ttl,
	keyid_t keyid,
	u_char *keystr
	)
{
#ifndef SYS_VXWORKS
	if (res_fp == NULL) {
#ifndef SYS_WINNT
		(void) strcpy(res_file, RES_TEMPFILE);
#else
		/* no /tmp directory under NT */
		{
			if(!(GetTempPath((DWORD)MAX_PATH, (LPTSTR)res_file))) {
				msyslog(LOG_ERR, "cannot get pathname for temporary directory: %m");
				return;
			}
			(void) strcat(res_file, "ntpdXXXXXX");
		}
#endif /* SYS_WINNT */
#ifdef HAVE_MKSTEMP
		{
			int fd;

			res_fp = NULL;
			if ((fd = mkstemp(res_file)) != -1)
				res_fp = fdopen(fd, "r+");
		}
#else
		(void) mktemp(res_file);
		res_fp = fopen(res_file, "w");
#endif
		if (res_fp == NULL) {
			msyslog(LOG_ERR, "open failed for %s: %m", res_file);
			return;
		}
	}
#ifdef DEBUG
	if (debug) {
		printf("resolving %s\n", name);
	}
#endif

	(void)fprintf(res_fp, "%s %d %d %d %d %d %d %u %s\n", name,
	    mode, version, minpoll, maxpoll, flags, ttl, keyid, keystr);
#ifdef DEBUG
	if (debug > 1)
		printf("config: %s %d %d %d %d %x %d %u %s\n", name, mode,
		    version, minpoll, maxpoll, flags, ttl, keyid, keystr);
#endif

#else  /* SYS_VXWORKS */
	/* save resolve info to a struct */
#endif /* SYS_VXWORKS */
}


/*
 * abort_resolve - terminate the resolver stuff and delete the file
 */
static void
abort_resolve(void)
{
	/*
	 * In an ideal world we would might reread the file and
	 * log the hosts which aren't getting configured.  Since
	 * this is too much work, however, just close and delete
	 * the temp file.
	 */
	if (res_fp != NULL)
		(void) fclose(res_fp);
	res_fp = NULL;

#ifndef SYS_VXWORKS		/* we don't open the file to begin with */
#if !defined(VMS)
	(void) unlink(res_file);
#else
	(void) delete(res_file);
#endif /* VMS */
#endif /* SYS_VXWORKS */
}


/*
 * do_resolve_internal - start up the resolver function (not program)
 */
/*
 * On VMS, this routine will simply refuse to resolve anything.
 *
 * Possible implementation: keep `res_file' in memory, do async
 * name resolution via QIO, update from within completion AST.
 * I'm unlikely to find the time for doing this, though. -wjm
 */
static void
do_resolve_internal(void)
{
	int i;

	if (res_fp == NULL) {
		/* belch */
		msyslog(LOG_ERR,
			"do_resolve_internal: Fatal: res_fp == NULL");
		exit(1);
	}

	/* we are done with this now */
	(void) fclose(res_fp);
	res_fp = NULL;

#if !defined(VMS) && !defined (SYS_VXWORKS)
	req_file = res_file;	/* set up pointer to res file */
#ifndef SYS_WINNT
	(void) signal_no_reset(SIGCHLD, catchchild);

#ifndef SYS_VXWORKS
	i = fork();
	if (i == 0) {
		/*
		 * this used to close everything
		 * I don't think this is necessary
		 */
		/*
		 * To the unknown commenter above:
		 * Well, I think it's better to clean up
		 * after oneself. I have had problems with
		 * refclock-io when intres was running - things
		 * where fine again when ntpintres was gone.
		 * So some systems react erratic at least.
		 *
		 *			Frank Kardel
		 *
		 * 94-11-16:
		 * Further debugging has proven that the above is
		 * absolutely harmful. The internal resolver
		 * is still in the SIGIO process group and the lingering
		 * async io information causes it to process requests from
		 * all file decriptor causing a race between the NTP daemon
		 * and the resolver. which then eats data when it wins 8-(.
		 * It is absolutly necessary to kill any IO associations
		 * shared with the NTP daemon.
		 *
		 * We also block SIGIO (currently no ports means to
		 * disable the signal handle for IO).
		 *
		 * Thanks to [e-mail] to notice
		 * that it is the ntp-resolver child running into trouble.
		 *
		 * THUS:
		 */

		closelog();
		kill_asyncio(0);

		(void) signal_no_reset(SIGCHLD, SIG_DFL);

#ifdef DEBUG
		if (0)
		    debug = 2;
#endif

# ifndef LOG_DAEMON
		openlog("ntpd_initres", LOG_PID);
# else /* LOG_DAEMON */

#  ifndef LOG_NTP
#   define	LOG_NTP LOG_DAEMON
#  endif
		openlog("ntpd_initres", LOG_PID | LOG_NDELAY, LOG_NTP);
#ifndef SYS_CYGWIN32
#  ifdef DEBUG
		if (debug)
		    setlogmask(LOG_UPTO(LOG_DEBUG));
		else
#  endif /* DEBUG */
		    setlogmask(LOG_UPTO(LOG_DEBUG)); /* @@@ was INFO */
# endif /* LOG_DAEMON */
#endif

		ntp_intres();

		/*
		 * If we got here, the intres code screwed up.
		 * Print something so we don't die without complaint
		 */
		msyslog(LOG_ERR, "call to ntp_intres lost");
		abort_resolve();
		exit(1);
	}
#else
	 /* vxWorks spawns a thread... -casey */
	 i = sp (ntp_intres);
	 /*i = taskSpawn("ntp_intres",100,VX_FP_TASK,20000,ntp_intres);*/
#endif
	if (i == -1) {
		msyslog(LOG_ERR, "fork() failed, can't start ntp_intres: %m");
		(void) signal_no_reset(SIGCHLD, SIG_DFL);
		abort_resolve();
	}
#else /* SYS_WINNT */
	{
		/* NT's equivalent of fork() is _spawn(), but the start point
		 * of the new process is an executable filename rather than
		 * a function name as desired here.
		 */
		DWORD dwThreadId;
		fflush(stdout);
		ResolverThreadHandle = CreateThread(
			NULL,				 /* no security attributes	*/
			0,				 /* use default stack size	*/
			(LPTHREAD_START_ROUTINE) ntp_intres, /* thread function		*/
			NULL,				 /* argument to thread function   */
			0,				 /* use default creation flags	  */
			&dwThreadId);			 /* returns the thread identifier */
		if (ResolverThreadHandle == NULL) {
			msyslog(LOG_ERR, "CreateThread() failed, can't start ntp_intres");
			abort_resolve();
		}
	}
#endif /* SYS_WINNT */
#else /* VMS  VX_WORKS */
	msyslog(LOG_ERR,
		"Name resolution not implemented for VMS - use numeric addresses");
	abort_resolve();
#endif /* VMS VX_WORKS */
}