ntpq.c

网络时间协议NTP 源码 版本v4.2.0b 该源码用于linux平台下

	 */
	if (!havehost) {
		(void) fprintf(stderr, "***No host open, use `host' command\n");
		return -1;
	}

	done = 0;
	sequence++;

    again:
	/*
	 * send a request
	 */
	res = sendrequest(opcode, associd, auth, qsize, qdata);
	if (res != 0)
	    return res;
	
	/*
	 * Get the response.  If we got a standard error, print a message
	 */
	res = getresponse(opcode, associd, rstatus, rsize, rdata, done);

	if (res > 0) {
		if (!done && (res == ERR_TIMEOUT || res == ERR_INCOMPLETE)) {
			if (res == ERR_INCOMPLETE) {
				/*
				 * better bump the sequence so we don't
				 * get confused about differing fragments.
				 */
				sequence++;
			}
			done = 1;
			goto again;
		}
		if (numhosts > 1)
			(void) fprintf(stderr, "server=%s ", currenthost);
		switch(res) {
		    case CERR_BADFMT:
			(void) fprintf(stderr,
			    "***Server reports a bad format request packet\n");
			break;
		    case CERR_PERMISSION:
			(void) fprintf(stderr,
			    "***Server disallowed request (authentication?)\n");
			break;
		    case CERR_BADOP:
			(void) fprintf(stderr,
			    "***Server reports a bad opcode in request\n");
			break;
		    case CERR_BADASSOC:
			(void) fprintf(stderr,
			    "***Association ID %d unknown to server\n",associd);
			break;
		    case CERR_UNKNOWNVAR:
			(void) fprintf(stderr,
			    "***A request variable unknown to the server\n");
			break;
		    case CERR_BADVALUE:
			(void) fprintf(stderr,
			    "***Server indicates a request variable was bad\n");
			break;
		    case ERR_UNSPEC:
			(void) fprintf(stderr,
			    "***Server returned an unspecified error\n");
			break;
		    case ERR_TIMEOUT:
			(void) fprintf(stderr, "***Request timed out\n");
			break;
		    case ERR_INCOMPLETE:
			(void) fprintf(stderr,
			    "***Response from server was incomplete\n");
			break;
		    case ERR_TOOMUCH:
			(void) fprintf(stderr,
			    "***Buffer size exceeded for returned data\n");
			break;
		    default:
			(void) fprintf(stderr,
			    "***Server returns unknown error code %d\n", res);
			break;
		}
	}
	return res;
}


/*
 * getcmds - read commands from the standard input and execute them
 */
static void
getcmds(void)
{
#if defined(HAVE_LIBREADLINE) || defined(HAVE_LIBEDIT)
        char *line;

        for (;;) {
                if ((line = readline(interactive?prompt:"")) == NULL) return;
                if (*line) add_history(line);
                docmd(line);
                free(line);
        }
#else /* not (HAVE_LIBREADLINE || HAVE_LIBEDIT) */
        char line[MAXLINE];

        for (;;) {
                if (interactive) {
#ifdef VMS      /* work around a problem with mixing stdout & stderr */
                        fputs("",stdout);
#endif
                        (void) fputs(prompt, stderr);
                        (void) fflush(stderr);
                }

                if (fgets(line, sizeof line, stdin) == NULL)
                    return;

                docmd(line);
        }
#endif /* not (HAVE_LIBREADLINE || HAVE_LIBEDIT) */
}

#ifndef SYS_WINNT /* Under NT cannot handle SIGINT, WIN32 spawns a handler */
/*
 * abortcmd - catch interrupts and abort the current command
 */
static RETSIGTYPE
abortcmd(
	int sig
	)
{
	if (current_output == stdout)
	    (void) fflush(stdout);
	putc('\n', stderr);
	(void) fflush(stderr);
	if (jump) longjmp(interrupt_buf, 1);
}
#endif	/* SYS_WINNT */

/*
 * docmd - decode the command line and execute a command
 */
static void
docmd(
	const char *cmdline
	)
{
	char *tokens[1+MAXARGS+2];
	struct parse pcmd;
	int ntok;
	static int i;
	struct xcmd *xcmd;

	/*
	 * Tokenize the command line.  If nothing on it, return.
	 */
	tokenize(cmdline, tokens, &ntok);
	if (ntok == 0)
	    return;
	
	/*
	 * Find the appropriate command description.
	 */
	i = findcmd(tokens[0], builtins, opcmds, &xcmd);
	if (i == 0) {
		(void) fprintf(stderr, "***Command `%s' unknown\n",
			       tokens[0]);
		return;
	} else if (i >= 2) {
		(void) fprintf(stderr, "***Command `%s' ambiguous\n",
			       tokens[0]);
		return;
	}
	
	/*
	 * Save the keyword, then walk through the arguments, interpreting
	 * as we go.
	 */
	pcmd.keyword = tokens[0];
	pcmd.nargs = 0;
	for (i = 0; i < MAXARGS && xcmd->arg[i] != NO; i++) {
		if ((i+1) >= ntok) {
			if (!(xcmd->arg[i] & OPT)) {
				printusage(xcmd, stderr);
				return;
			}
			break;
		}
		if ((xcmd->arg[i] & OPT) && (*tokens[i+1] == '>'))
		    break;
		if (!getarg(tokens[i+1], (int)xcmd->arg[i], &pcmd.argval[i]))
		    return;
		pcmd.nargs++;
	}

	i++;
	if (i < ntok && *tokens[i] == '>') {
		char *fname;

		if (*(tokens[i]+1) != '\0')
		    fname = tokens[i]+1;
		else if ((i+1) < ntok)
		    fname = tokens[i+1];
		else {
			(void) fprintf(stderr, "***No file for redirect\n");
			return;
		}

		current_output = fopen(fname, "w");
		if (current_output == NULL) {
			(void) fprintf(stderr, "***Error opening %s: ", fname);
			perror("");
			return;
		}
		i = 1;		/* flag we need a close */
	} else {
		current_output = stdout;
		i = 0;		/* flag no close */
	}

	if (interactive && setjmp(interrupt_buf)) {
		jump = 0;
		return;
	} else {
		jump++;
		(xcmd->handler)(&pcmd, current_output);
		jump = 0;	/* HMS: 961106: was after fclose() */
		if (i) (void) fclose(current_output);
	}
}


/*
 * tokenize - turn a command line into tokens
 */
static void
tokenize(
	const char *line,
	char **tokens,
	int *ntok
	)
{
	register const char *cp;
	register char *sp;
	static char tspace[MAXLINE];

	sp = tspace;
	cp = line;
	for (*ntok = 0; *ntok < MAXTOKENS; (*ntok)++) {
		tokens[*ntok] = sp;
		while (ISSPACE(*cp))
		    cp++;
		if (ISEOL(*cp))
		    break;
		do {
			*sp++ = *cp++;
		} while (!ISSPACE(*cp) && !ISEOL(*cp));

		*sp++ = '\0';
	}
}



/*
 * findcmd - find a command in a command description table
 */
static int
findcmd(
	register char *str,
	struct xcmd *clist1,
	struct xcmd *clist2,
	struct xcmd **cmd
	)
{
	register struct xcmd *cl;
	register int clen;
	int nmatch;
	struct xcmd *nearmatch = NULL;
	struct xcmd *clist;

	clen = strlen(str);
	nmatch = 0;
	if (clist1 != 0)
	    clist = clist1;
	else if (clist2 != 0)
	    clist = clist2;
	else
	    return 0;

    again:
	for (cl = clist; cl->keyword != 0; cl++) {
		/* do a first character check, for efficiency */
		if (*str != *(cl->keyword))
		    continue;
		if (strncmp(str, cl->keyword, (unsigned)clen) == 0) {
			/*
			 * Could be extact match, could be approximate.
			 * Is exact if the length of the keyword is the
			 * same as the str.
			 */
			if (*((cl->keyword) + clen) == '\0') {
				*cmd = cl;
				return 1;
			}
			nmatch++;
			nearmatch = cl;
		}
	}

	/*
	 * See if there is more to do.  If so, go again.  Sorry about the
	 * goto, too much looking at BSD sources...
	 */
	if (clist == clist1 && clist2 != 0) {
		clist = clist2;
		goto again;
	}

	/*
	 * If we got extactly 1 near match, use it, else return number
	 * of matches.
	 */
	if (nmatch == 1) {
		*cmd = nearmatch;
		return 1;
	}
	return nmatch;
}


/*
 * getarg - interpret an argument token
 */
static int
getarg(
	char *str,
	int code,
	arg_v *argp
	)
{
	int isneg;
	char *cp, *np;
	static const char *digits = "0123456789";

	switch (code & ~OPT) {
	    case NTP_STR:
		argp->string = str;
		break;
	    case NTP_ADD:
		if (!getnetnum(str, &(argp->netnum), (char *)0, 0)) {
			return 0;
		}
		break;
	    case NTP_INT:
	    case NTP_UINT:
		isneg = 0;
		np = str;
		if (*np == '&') {
			np++;
			isneg = atoi(np);
			if (isneg <= 0) {
				(void) fprintf(stderr,
					       "***Association value `%s' invalid/undecodable\n", str);
				return 0;
			}
			if (isneg > numassoc) {
				if (numassoc == 0) {
					(void) fprintf(stderr,
						       "***Association for `%s' unknown (max &%d)\n",
						       str, numassoc);
					return 0;
				} else {
					isneg = numassoc;
				}
			}
			argp->uval = assoc_cache[isneg-1].assid;
			break;
		}

		if (*np == '-') {
			np++;
			isneg = 1;
		}

		argp->uval = 0;
		do {
			cp = strchr(digits, *np);
			if (cp == NULL) {
				(void) fprintf(stderr,
					       "***Illegal integer value %s\n", str);
				return 0;
			}
			argp->uval *= 10;
			argp->uval += (cp - digits);
		} while (*(++np) != '\0');

		if (isneg) {
			if ((code & ~OPT) == NTP_UINT) {
				(void) fprintf(stderr,
					       "***Value %s should be unsigned\n", str);
				return 0;
			}
			argp->ival = -argp->ival;
		}
		break;
	     case IP_VERSION:
		if (!strcmp("-6", str))
			argp->ival = 6 ;
		else if (!strcmp("-4", str))
			argp->ival = 4 ;
		else {
			(void) fprintf(stderr,
			    "***Version must be either 4 or 6\n");
			return 0;
		}
		break;
	}

	return 1;
}


/*
 * getnetnum - given a host name, return its net number
 *	       and (optional) full name
 */
int
getnetnum(
	const char *hname,
	struct sockaddr_storage *num,
	char *fullhost,
	int af
	)
{
	int sockaddr_len;
	struct addrinfo hints, *ai = NULL;

	sockaddr_len = (af == AF_INET)
			   ? sizeof(struct sockaddr_in)
			   : sizeof(struct sockaddr_in6);
	memset((char *)&hints, 0, sizeof(struct addrinfo));
	hints.ai_flags = AI_CANONNAME;
#ifdef AI_ADDRCONFIG
	hints.ai_flags |= AI_ADDRCONFIG;
#endif
	
	/* decodenetnum works with addresses only */
	if (decodenetnum(hname, num)) {
		if (fullhost != 0) {
			getnameinfo((struct sockaddr *)num, sockaddr_len,
					fullhost, sizeof(fullhost), NULL, 0,
					NI_NUMERICHOST);
		}
		return 1;
	} else if (getaddrinfo(hname, "ntp", &hints, &ai) == 0) {
		memmove((char *)num, ai->ai_addr, ai->ai_addrlen);
		if (ai->ai_canonname != 0)
		    (void) strcpy(fullhost, ai->ai_canonname);
		return 1;
	} else {
		(void) fprintf(stderr, "***Can't find host %s\n", hname);
		return 0;
	}
	/*NOTREACHED*/
}

/*
 * nntohost - convert network number to host name.  This routine enforces
 *	       the showhostnames setting.
 */
char *
nntohost(
	struct sockaddr_storage *netnum
	)
{
	if (!showhostnames)
	    return stoa(netnum);
	if ((netnum->ss_family == AF_INET) && ISREFCLOCKADR(netnum))
    		return refnumtoa(netnum);
	return socktohost(netnum);
}


/*
 * rtdatetolfp - decode an RT-11 date into an l_fp
 */
static int
rtdatetolfp(
	char *str,
	l_fp *lfp
	)
{
	register char *cp;
	register int i;
	struct calendar cal;
	char buf[4];
	static const char *months[12] = {
		"Jan", "Feb", "Mar", "Apr", "May", "Jun",
		"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
	};

	cal.yearday = 0;

	/*
	 * An RT-11 date looks like:
	 *
	 * d[d]-Mth-y[y] hh:mm:ss
	 *
	 * (No docs, but assume 4-digit years are also legal...)
	 *
	 * d[d]-Mth-y[y[y[y]]] hh:mm:ss
	 */
	cp = str;
	if (!isdigit((int)*cp)) {
		if (*cp == '-') {
			/*
			 * Catch special case
			 */
			L_CLR(lfp);
			return 1;
		}
		return 0;
	}

	cal.monthday = (u_char) (*cp++ - '0');	/* ascii dependent */
	if (isdigit((int)*cp)) {
		cal.monthday = (u_char)((cal.monthday << 3) + (cal.monthday << 1));
		cal.monthday = (u_char)(cal.monthday + *cp++ - '0');
	}

	if (*cp++ != '-')
	    return 0;
	
	for (i = 0; i < 3; i++)
	    buf[i] = *cp++;
	buf[3] = '\0';

	for (i = 0; i < 12; i++)
	    if (STREQ(buf, months[i]))
		break;
	if (i == 12)
	    return 0;
	cal.month = (u_char)(i + 1);

	if (*cp++ != '-')
	    return 0;
	
	if (!isdigit((int)*cp))
	    return 0;
	cal.year = (u_short)(*cp++ - '0');
	if (isdigit((int)*cp)) {
		cal.year = (u_short)((cal.year << 3) + (cal.year << 1));
		cal.year = (u_short)(*cp++ - '0');
	}
	if (isdigit((int)*cp)) {
		cal.year = (u_short)((cal.year << 3) + (cal.year << 1));
		cal.year = (u_short)(cal.year + *cp++ - '0');
	}
	if (isdigit((int)*cp)) {
		cal.year = (u_short)((cal.year << 3) + (cal.year << 1));
		cal.year = (u_short)(cal.year + *cp++ - '0');
	}

	/*
	 * Catch special case.  If cal.year == 0 this is a zero timestamp.
	 */
	if (cal.year == 0) {
		L_CLR(lfp);
		return 1;
	}

	if (*cp++ != ' ' || !isdigit((int)*cp))
	    return 0;
	cal.hour = (u_char)(*cp++ - '0');
	if (isdigit((int)*cp)) {
		cal.hour = (u_char)((cal.hour << 3) + (cal.hour << 1));
		cal.hour = (u_char)(cal.hour + *cp++ - '0');
	}

	if (*cp++ != ':' || !isdigit((int)*cp))
	    return 0;
	cal.minute = (u_char)(*cp++ - '0');
	if (isdigit((int)*cp)) {
		cal.minute = (u_char)((cal.minute << 3) + (cal.minute << 1));
		cal.minute = (u_char)(cal.minute + *cp++ - '0');
	}

	if (*cp++ != ':' || !isdigit((int)*cp))
	    return 0;
	cal.second = (u_char)(*cp++ - '0');
	if (isdigit((int)*cp)) {
		cal.second = (u_char)((cal.second << 3) + (cal.second << 1));
		cal.second = (u_char)(cal.second + *cp++ - '0');
	}

	/*
	 * For RT-11, 1972 seems to be the pivot year
	 */
	if (cal.year < 72)
		cal.year += 2000;
	if (cal.year < 100)
		cal.year += 1900;

	lfp->l_ui = caltontp(&cal);
	lfp->l_uf = 0;
	return 1;
}


/*
 * decodets - decode a timestamp into an l_fp format number, with
 *	      consideration of fuzzball formats.
 */
int
decodets(
	char *str,
	l_fp *lfp
	)
{
	/*
	 * If it starts with a 0x, decode as hex.
	 */
	if (*str == '0' && (*(str+1) == 'x' || *(str+1) == 'X'))