ntp_control.c

网络时间协议NTP 源码 版本v4.2.0b 该源码用于linux平台下

				    (u_int32)clock_stat->fudgeval2, NULL);
			else
				ctl_putid(clock_var[CC_FUDGEVAL2].text,
				    (char *)&clock_stat->fudgeval2);
		}
		break;

	case CC_FLAGS:
		if (mustput || (clock_stat->haveflags &	(CLK_HAVEFLAG1 |
		    CLK_HAVEFLAG2 | CLK_HAVEFLAG3 | CLK_HAVEFLAG4)))
			ctl_putuint(clock_var[CC_FLAGS].text,
			    clock_stat->flags);
		break;

	case CC_DEVICE:
		if (clock_stat->clockdesc == NULL ||
		    *(clock_stat->clockdesc) == '\0') {
			if (mustput)
				ctl_putstr(clock_var[CC_DEVICE].text,
				    "", 0);
		} else {
			ctl_putstr(clock_var[CC_DEVICE].text,
			    clock_stat->clockdesc,
			    strlen(clock_stat->clockdesc));
		}
		break;

	case CC_VARLIST:
		{
			char buf[CTL_MAX_DATA_LEN];
			register char *s, *t, *be;
			register const char *ss;
			register int i;
			register struct ctl_var *k;

			s = buf;
			be = buf + sizeof(buf);
			if (s + strlen(clock_var[CC_VARLIST].text) + 4 >
			    be)
				break;	/* really long var name */

			strcpy(s, clock_var[CC_VARLIST].text);
			strcat(s, "=\"");
			s += strlen(s);
			t = s;

			for (k = clock_var; !(k->flags &EOV); k++) {
				if (k->flags & PADDING)
					continue;

				i = strlen(k->text);
				if (s + i + 1 >= be)
					break;

				if (s != t)
				*s++ = ',';
				strcpy(s, k->text);
				s += i;
			}

			for (k = clock_stat->kv_list; k && !(k->flags &
			    EOV); k++) {
				if (k->flags & PADDING)
					continue;

				ss = k->text;
				if (!ss)
					continue;

				while (*ss && *ss != '=')
					ss++;
				i = ss - k->text;
				if (s+i+1 >= be)
					break;

				if (s != t)
					*s++ = ',';
				strncpy(s, k->text, (unsigned)i);
				s += i;
				*s = '\0';
			}
			if (s+2 >= be)
				break;

			*s++ = '"';
			*s = '\0';
			ctl_putdata(buf, (unsigned)( s - buf ), 0);
		}
		break;
	}
}
#endif



/*
 * ctl_getitem - get the next data item from the incoming packet
 */
static struct ctl_var *
ctl_getitem(
	struct ctl_var *var_list,
	char **data
	)
{
	register struct ctl_var *v;
	register char *cp;
	register char *tp;
	static struct ctl_var eol = { 0, EOV, };
	static char buf[128];

	/*
	 * Delete leading commas and white space
	 */
	while (reqpt < reqend && (*reqpt == ',' ||
	    isspace((unsigned char)*reqpt)))
		reqpt++;
	if (reqpt >= reqend)
		return (0);

	if (var_list == (struct ctl_var *)0)
		return (&eol);

	/*
	 * Look for a first character match on the tag.  If we find
	 * one, see if it is a full match.
	 */
	v = var_list;
	cp = reqpt;
	while (!(v->flags & EOV)) {
		if (!(v->flags & PADDING) && *cp == *(v->text)) {
			tp = v->text;
			while (*tp != '\0' && *tp != '=' && cp <
			    reqend && *cp == *tp) {
				cp++;
				tp++;
			}
			if ((*tp == '\0') || (*tp == '=')) {
				while (cp < reqend && isspace((unsigned char)*cp))
					cp++;
				if (cp == reqend || *cp == ',') {
					buf[0] = '\0';
					*data = buf;
					if (cp < reqend)
						cp++;
					reqpt = cp;
					return v;
				}
				if (*cp == '=') {
					cp++;
					tp = buf;
					while (cp < reqend && isspace((unsigned char)*cp))
						cp++;
					while (cp < reqend && *cp != ',') {
						*tp++ = *cp++;
						if (tp >= buf + sizeof(buf)) {
							ctl_error(CERR_BADFMT);
							numctlbadpkts++;
#if 0	/* Avoid possible DOS attack */
/* If we get a smarter msyslog we can re-enable this */
							msyslog(LOG_WARNING,
		"Possible 'ntpdx' exploit from %s:%d (possibly spoofed)\n",
		stoa(rmt_addr), SRCPORT(rmt_addr)
								);
#endif
							return (0);
						}
					}
					if (cp < reqend)
						cp++;
					*tp-- = '\0';
					while (tp >= buf) {
						if (!isspace((unsigned int)(*tp)))
							break;
						*tp-- = '\0';
					}
					reqpt = cp;
					*data = buf;
					return (v);
				}
			}
			cp = reqpt;
		}
		v++;
	}
	return v;
}


/*
 * control_unspec - response to an unspecified op-code
 */
/*ARGSUSED*/
static void
control_unspec(
	struct recvbuf *rbufp,
	int restrict_mask
	)
{
	struct peer *peer;

	/*
	 * What is an appropriate response to an unspecified op-code?
	 * I return no errors and no data, unless a specified assocation
	 * doesn't exist.
	 */
	if (res_associd != 0) {
		if ((peer = findpeerbyassoc(res_associd)) == 0) {
			ctl_error(CERR_BADASSOC);
			return;
		}
		rpkt.status = htons(ctlpeerstatus(peer));
	} else {
		rpkt.status = htons(ctlsysstatus());
	}
	ctl_flushpkt(0);
}


/*
 * read_status - return either a list of associd's, or a particular
 * peer's status.
 */
/*ARGSUSED*/
static void
read_status(
	struct recvbuf *rbufp,
	int restrict_mask
	)
{
	register int i;
	register struct peer *peer;
	u_short ass_stat[CTL_MAX_DATA_LEN / sizeof(u_short)];

#ifdef DEBUG
	if (debug > 2)
		printf("read_status: ID %d\n", res_associd);
#endif
	/*
	 * Two choices here. If the specified association ID is
	 * zero we return all known assocation ID's.  Otherwise
	 * we return a bunch of stuff about the particular peer.
	 */
	if (res_associd == 0) {
		register int n;

		n = 0;
		rpkt.status = htons(ctlsysstatus());
		for (i = 0; i < NTP_HASH_SIZE; i++) {
			for (peer = assoc_hash[i]; peer != 0;
				peer = peer->ass_next) {
				ass_stat[n++] = htons(peer->associd);
				ass_stat[n++] =
				    htons(ctlpeerstatus(peer));
				if (n ==
				    CTL_MAX_DATA_LEN/sizeof(u_short)) {
					ctl_putdata((char *)ass_stat,
					    n * sizeof(u_short), 1);
					n = 0;
				}
			}
		}

		if (n != 0)
			ctl_putdata((char *)ass_stat, n *
			    sizeof(u_short), 1);
		ctl_flushpkt(0);
	} else {
		peer = findpeerbyassoc(res_associd);
		if (peer == 0) {
			ctl_error(CERR_BADASSOC);
		} else {
			register u_char *cp;

			rpkt.status = htons(ctlpeerstatus(peer));
			if (res_authokay)
				peer->num_events = 0;
			/*
			 * For now, output everything we know about the
			 * peer. May be more selective later.
			 */
			for (cp = def_peer_var; *cp != 0; cp++)
				ctl_putpeer((int)*cp, peer);
			ctl_flushpkt(0);
		}
	}
}


/*
 * read_variables - return the variables the caller asks for
 */
/*ARGSUSED*/
static void
read_variables(
	struct recvbuf *rbufp,
	int restrict_mask
	)
{
	register struct ctl_var *v;
	register int i;
	char *valuep;
	u_char *wants;
	unsigned int gotvar = (CS_MAXCODE > CP_MAXCODE) ? (CS_MAXCODE +
	    1) : (CP_MAXCODE + 1);
	if (res_associd == 0) {
		/*
		 * Wants system variables. Figure out which he wants
		 * and give them to him.
		 */
		rpkt.status = htons(ctlsysstatus());
		if (res_authokay)
			ctl_sys_num_events = 0;
		gotvar += count_var(ext_sys_var);
		wants = (u_char *)emalloc(gotvar);
		memset((char *)wants, 0, gotvar);
		gotvar = 0;
		while ((v = ctl_getitem(sys_var, &valuep)) != 0) {
			if (v->flags & EOV) {
				if ((v = ctl_getitem(ext_sys_var,
				    &valuep)) != 0) {
					if (v->flags & EOV) {
						ctl_error(CERR_UNKNOWNVAR);
						free((char *)wants);
						return;
					}
					wants[CS_MAXCODE + 1 +
					    v->code] = 1;
					gotvar = 1;
					continue;
				} else {
					break; /* shouldn't happen ! */
				}
			}
			wants[v->code] = 1;
			gotvar = 1;
		}
		if (gotvar) {
			for (i = 1; i <= CS_MAXCODE; i++)
				if (wants[i])
					ctl_putsys(i);
			for (i = 0; ext_sys_var &&
			    !(ext_sys_var[i].flags & EOV); i++)
				if (wants[i + CS_MAXCODE + 1])
					ctl_putdata(ext_sys_var[i].text,
					    strlen(ext_sys_var[i].text),
					    0);
		} else {
			register u_char *cs;
			register struct ctl_var *kv;

			for (cs = def_sys_var; *cs != 0; cs++)
				ctl_putsys((int)*cs);
			for (kv = ext_sys_var; kv && !(kv->flags & EOV);
			    kv++)
				if (kv->flags & DEF)
					ctl_putdata(kv->text,
					    strlen(kv->text), 0);
		}
		free((char *)wants);
	} else {
		register struct peer *peer;

		/*
		 * Wants info for a particular peer. See if we know
		 * the guy.
		 */
		peer = findpeerbyassoc(res_associd);
		if (peer == 0) {
			ctl_error(CERR_BADASSOC);
			return;
		}
		rpkt.status = htons(ctlpeerstatus(peer));
		if (res_authokay)
			peer->num_events = 0;
		wants = (u_char *)emalloc(gotvar);
		memset((char*)wants, 0, gotvar);
		gotvar = 0;
		while ((v = ctl_getitem(peer_var, &valuep)) != 0) {
			if (v->flags & EOV) {
				ctl_error(CERR_UNKNOWNVAR);
				free((char *)wants);
				return;
			}
			wants[v->code] = 1;
			gotvar = 1;
		}
		if (gotvar) {
			for (i = 1; i <= CP_MAXCODE; i++)
				if (wants[i])
					ctl_putpeer(i, peer);
		} else {
			register u_char *cp;

			for (cp = def_peer_var; *cp != 0; cp++)
				ctl_putpeer((int)*cp, peer);
		}
		free((char *)wants);
	}
	ctl_flushpkt(0);
}


/*
 * write_variables - write into variables. We only allow leap bit
 * writing this way.
 */
/*ARGSUSED*/
static void
write_variables(
	struct recvbuf *rbufp,
	int restrict_mask
	)
{
	register struct ctl_var *v;
	register int ext_var;
	char *valuep;
	long val = 0;

	/*
	 * If he's trying to write into a peer tell him no way
	 */
	if (res_associd != 0) {
		ctl_error(CERR_PERMISSION);
		return;
	}

	/*
	 * Set status
	 */
	rpkt.status = htons(ctlsysstatus());

	/*
	 * Look through the variables. Dump out at the first sign of
	 * trouble.
	 */
	while ((v = ctl_getitem(sys_var, &valuep)) != 0) {
		ext_var = 0;
		if (v->flags & EOV) {
			if ((v = ctl_getitem(ext_sys_var, &valuep)) !=
			    0) {
				if (v->flags & EOV) {
					ctl_error(CERR_UNKNOWNVAR);
					return;
				}
				ext_var = 1;
			} else {
				break;
			}
		}
		if (!(v->flags & CAN_WRITE)) {
			ctl_error(CERR_PERMISSION);
			return;
		}
		if (!ext_var && (*valuep == '\0' || !atoint(valuep,
		    &val))) {
			ctl_error(CERR_BADFMT);
			return;
		}
		if (!ext_var && (val & ~LEAP_NOTINSYNC) != 0) {
			ctl_error(CERR_BADVALUE);
			return;
		}

		if (ext_var) {
			char *s = (char *)emalloc(strlen(v->text) +
			    strlen(valuep) + 2);
			const char *t;
			char *tt = s;

			t = v->text;
			while (*t && *t != '=')
				*tt++ = *t++;

			*tt++ = '=';
			strcat(tt, valuep);
			set_sys_var(s, strlen(s)+1, v->flags);
			free(s);
		} else {
			/*
			 * This one seems sane. Save it.
			 */
			switch(v->code) {

			case CS_LEAP:
			default:
				ctl_error(CERR_UNSPEC); /* really */
				return;
			}
		}
	}

	/*
	 * If we got anything, do it. xxx nothing to do ***
	 */
	/*
	  if (leapind != ~0 || leapwarn != ~0) {
	  	if (!leap_setleap((int)leapind, (int)leapwarn)) {
	  		ctl_error(CERR_PERMISSION);
	  		return;
	  	}
	  }
	*/
	ctl_flushpkt(0);
}


/*
 * read_clock_status - return clock radio status
 */
/*ARGSUSED*/
static void
read_clock_status(
	struct recvbuf *rbufp,
	int restrict_mask
	)
{
#ifndef REFCLOCK
	/*
	 * If no refclock support, no data to return
	 */
	ctl_error(CERR_BADASSOC);
#else
	register struct ctl_var *v;
	register int i;
	register struct peer *peer;
	char *valuep;
	u_char *wants;
	unsigned int gotvar;
	struct refclockstat clock_stat;

	if (res_associd == 0) {

		/*
		 * Find a clock for this jerk.	If the system peer
		 * is a clock use it, else search the hash tables
		 * for one.
		 */
		if (sys_peer != 0 && (sys_peer->flags & FLAG_REFCLOCK))
		    {
			peer = sys_peer;
		} else {
			peer = 0;
			for (i = 0; peer == 0 && i < NTP_HASH_SIZE; i++) {
				for (peer = assoc_hash[i]; peer != 0;
					peer = peer->ass_next) {
					if (peer->flags & FLAG_REFCLOCK)
						break;
				}
			}
			if (peer == 0) {
				ctl_error(CERR_BADASSOC);
				return;
			}
		}
	} else {
		peer = findpeerbyassoc(res_associd);
		if (peer == 0 || !(peer->flags & FLAG_REFCLOCK)) {
			ctl_error(CERR_BADASSOC);
			return;
		}
	}

	/*
	 * If we got here we have a peer which is a clock. Get his
	 * status.
	 */
	clock_stat.kv_list = (struct ctl_var *)0;
	refclock_control(&peer->srcadr, (struct refclockstat *)0,
	    &clock_stat);

	/*
	 * Look for variables in the packet.
	 */
	rpkt.status = htons(ctlclkstatus(&clock_stat));
	gotvar = CC_MAXCODE + 1 + count_var(clock_stat.kv_list);
	wants = (u_char *)emalloc(gotvar);
	memset((char*)wants, 0, gotvar);
	gotvar = 0;
	while ((v = ctl_getitem(clock_var, &valuep)) != 0) {
		if (v->flags & EOV) {
			if ((v = ctl_getitem(clock_stat.kv_list,
			    &valuep)) != 0) {
				if (v->flags & EOV) {
					ctl_error(CERR_UNKNOWNVAR);
					free((char*)wants);
					free_varlist(clock_stat.kv_list);
					return;
				}
				wants[CC_MAXCODE + 1 + v->code] = 1;
				gotvar = 1;
				continue;
			} else {
				break; /* shouldn't happen ! */
			}
		}
		wants[v->code] = 1;
		gotvar = 1;
	}