ntp_request.c

网络时间协议NTP 源码 版本v4.2.0b 该源码用于linux平台下

#endif
		req_ack(srcadr, inter, inpkt, INFO_ERR_FMT);
		return;
	}
	if ((proc->sizeofitem != 0) &&
	    ((temp_size * INFO_NITEMS(inpkt->err_nitems)) >
	    (rbufp->recv_length - REQ_LEN_HDR))) {
#ifdef DEBUG
		if (debug > 2)
			printf("process_private: not enough data\n");
#endif
		req_ack(srcadr, inter, inpkt, INFO_ERR_FMT);
		return;
	}

	switch (inpkt->implementation) {
	case IMPL_XNTPD:
		client_v6_capable = 1;
		break;
	case IMPL_XNTPD_OLD:
		client_v6_capable = 0;
		break;
	default:
		req_ack(srcadr, inter, inpkt, INFO_ERR_FMT);
		return;
	}

	/*
	 * If we need to authenticate, do so.  Note that an
	 * authenticatable packet must include a mac field, must
	 * have used key info_auth_keyid and must have included
	 * a time stamp in the appropriate field.  The time stamp
	 * must be within INFO_TS_MAXSKEW of the receive
	 * time stamp.
	 */
	if (proc->needs_auth && sys_authenticate) {
		l_fp ftmp;
		double dtemp;
	
		if (rbufp->recv_length < (int)((REQ_LEN_HDR +
		    (INFO_ITEMSIZE(inpkt->mbz_itemsize) *
		    INFO_NITEMS(inpkt->err_nitems))
		    + sizeof(struct req_pkt_tail)))) {
			req_ack(srcadr, inter, inpkt, INFO_ERR_FMT);
		}
		tailinpkt = (struct req_pkt_tail *)((char *)&rbufp->recv_pkt +
		    rbufp->recv_length - sizeof(struct req_pkt_tail));

		/*
		 * If this guy is restricted from doing this, don't let him
		 * If wrong key was used, or packet doesn't have mac, return.
		 */
		if (!INFO_IS_AUTH(inpkt->auth_seq) || info_auth_keyid == 0
		    || ntohl(tailinpkt->keyid) != info_auth_keyid) {
#ifdef DEBUG
			if (debug > 4)
			    printf("failed auth %d info_auth_keyid %lu pkt keyid %lu\n",
				   INFO_IS_AUTH(inpkt->auth_seq),
				   (u_long)info_auth_keyid,
				   (u_long)ntohl(tailinpkt->keyid));
			msyslog(LOG_DEBUG,
				"process_private: failed auth %d info_auth_keyid %lu pkt keyid %lu\n",
				INFO_IS_AUTH(inpkt->auth_seq),
				(u_long)info_auth_keyid,
				(u_long)ntohl(tailinpkt->keyid));
#endif
			req_ack(srcadr, inter, inpkt, INFO_ERR_AUTH);
			return;
		}
		if (rbufp->recv_length > REQ_LEN_MAC) {
#ifdef DEBUG
			if (debug > 4)
			    printf("bad pkt length %d\n",
				   rbufp->recv_length);
#endif
			msyslog(LOG_ERR, "process_private: bad pkt length %d",
				rbufp->recv_length);
			req_ack(srcadr, inter, inpkt, INFO_ERR_FMT);
			return;
		}
		if (!mod_okay || !authhavekey(info_auth_keyid)) {
#ifdef DEBUG
			if (debug > 4)
			    printf("failed auth mod_okay %d\n", mod_okay);
			msyslog(LOG_DEBUG,
				"process_private: failed auth mod_okay %d\n",
				mod_okay);
#endif
			req_ack(srcadr, inter, inpkt, INFO_ERR_AUTH);
			return;
		}

		/*
		 * calculate absolute time difference between xmit time stamp
		 * and receive time stamp.  If too large, too bad.
		 */
		NTOHL_FP(&tailinpkt->tstamp, &ftmp);
		L_SUB(&ftmp, &rbufp->recv_time);
		LFPTOD(&ftmp, dtemp);
		if (fabs(dtemp) >= INFO_TS_MAXSKEW) {
			/*
			 * He's a loser.  Tell him.
			 */
#ifdef DEBUG
			if (debug > 4)
			    printf("xmit/rcv timestamp delta > INFO_TS_MAXSKEW\n");
#endif
			req_ack(srcadr, inter, inpkt, INFO_ERR_AUTH);
			return;
		}

		/*
		 * So far so good.  See if decryption works out okay.
		 */
		if (!authdecrypt(info_auth_keyid, (u_int32 *)inpkt,
		    rbufp->recv_length - sizeof(struct req_pkt_tail) +
		    REQ_LEN_HDR, sizeof(struct req_pkt_tail) - REQ_LEN_HDR)) {
#ifdef DEBUG
			if (debug > 4)
			    printf("authdecrypt failed\n");
#endif
			req_ack(srcadr, inter, inpkt, INFO_ERR_AUTH);
			return;
		}
	}

#ifdef DEBUG
	if (debug > 3)
	    printf("process_private: all okay, into handler\n");
#endif

	/*
	 * Packet is okay.  Call the handler to send him data.
	 */
	(proc->handler)(srcadr, inter, inpkt);
}


/*
 * peer_list - send a list of the peers
 */
static void
peer_list(
	struct sockaddr_storage *srcadr,
	struct interface *inter,
	struct req_pkt *inpkt
	)
{
	register struct info_peer_list *ip;
	register struct peer *pp;
	register int i;
	register int skip = 0;

	ip = (struct info_peer_list *)prepare_pkt(srcadr, inter, inpkt,
	    v6sizeof(struct info_peer_list));
	for (i = 0; i < NTP_HASH_SIZE && ip != 0; i++) {
		pp = peer_hash[i];
		while (pp != 0 && ip != 0) {
			if (pp->srcadr.ss_family == AF_INET6) {
				if (client_v6_capable) {
					ip->addr6 = GET_INADDR6(pp->srcadr);
					ip->v6_flag = 1;
					skip = 0;
				} else {
					skip = 1;
					break;
				}
			} else {
				ip->addr = GET_INADDR(pp->srcadr);
				if (client_v6_capable)
					ip->v6_flag = 0;
				skip = 0;
			}

			if(!skip) {
				ip->port = NSRCPORT(&pp->srcadr);
				ip->hmode = pp->hmode;
				ip->flags = 0;
				if (pp->flags & FLAG_CONFIG)
				    ip->flags |= INFO_FLAG_CONFIG;
				if (pp == sys_peer)
				    ip->flags |= INFO_FLAG_SYSPEER;
				if (pp->status == CTL_PST_SEL_SYNCCAND)
				    ip->flags |= INFO_FLAG_SEL_CANDIDATE;
				if (pp->status >= CTL_PST_SEL_SYSPEER)
				    ip->flags |= INFO_FLAG_SHORTLIST;
				ip = (struct info_peer_list *)more_pkt();
			}
			pp = pp->next; 
		}
	}
	flush_pkt();
}


/*
 * peer_list_sum - return extended peer list
 */
static void
peer_list_sum(
	struct sockaddr_storage *srcadr,
	struct interface *inter,
	struct req_pkt *inpkt
	)
{
	register struct info_peer_summary *ips;
	register struct peer *pp;
	register int i;
	l_fp ltmp;
	register int skip;

#ifdef DEBUG
	if (debug > 2)
	    printf("wants peer list summary\n");
#endif
	ips = (struct info_peer_summary *)prepare_pkt(srcadr, inter, inpkt,
	    v6sizeof(struct info_peer_summary));
	for (i = 0; i < NTP_HASH_SIZE && ips != 0; i++) {
		pp = peer_hash[i];
		while (pp != 0 && ips != 0) {
#ifdef DEBUG
			if (debug > 3)
			    printf("sum: got one\n");
#endif
			/*
			 * Be careful here not to return v6 peers when we
			 * want only v4.
			 */
			if (pp->srcadr.ss_family == AF_INET6) {
				if (client_v6_capable) {
					ips->srcadr6 = GET_INADDR6(pp->srcadr);
					ips->v6_flag = 1;
					ips->dstadr6 = GET_INADDR6(pp->dstadr->sin);
					skip = 0;
				} else {
					skip = 1;
					break;
				}
			} else {
				ips->srcadr = GET_INADDR(pp->srcadr);
				if (client_v6_capable)
					ips->v6_flag = 0;
/* XXX PDM This code is buggy. Need to replace with a straightforward assignment */
				ips->dstadr = (pp->processed) ?
					pp->cast_flags == MDF_BCAST ?
					GET_INADDR(pp->dstadr->bcast):
					pp->cast_flags ?
					GET_INADDR(pp->dstadr->sin) ?
					GET_INADDR(pp->dstadr->sin):
					GET_INADDR(pp->dstadr->bcast):
					1 : GET_INADDR(pp->dstadr->sin);

				skip = 0;
			}
			if (!skip){ 
				ips->srcport = NSRCPORT(&pp->srcadr);
				ips->stratum = pp->stratum;
				ips->hpoll = pp->hpoll;
				ips->ppoll = pp->ppoll;
				ips->reach = pp->reach;
				ips->flags = 0;
				if (pp == sys_peer)
				    ips->flags |= INFO_FLAG_SYSPEER;
				if (pp->flags & FLAG_CONFIG)
				    ips->flags |= INFO_FLAG_CONFIG;
				if (pp->flags & FLAG_REFCLOCK)
				    ips->flags |= INFO_FLAG_REFCLOCK;
				if (pp->flags & FLAG_AUTHENABLE)
				    ips->flags |= INFO_FLAG_AUTHENABLE;
				if (pp->flags & FLAG_PREFER)
				    ips->flags |= INFO_FLAG_PREFER;
				if (pp->flags & FLAG_BURST)
				    ips->flags |= INFO_FLAG_BURST;
				if (pp->status == CTL_PST_SEL_SYNCCAND)
				    ips->flags |= INFO_FLAG_SEL_CANDIDATE;
				if (pp->status >= CTL_PST_SEL_SYSPEER)
				    ips->flags |= INFO_FLAG_SHORTLIST;
				ips->hmode = pp->hmode;
				ips->delay = HTONS_FP(DTOFP(pp->delay));
				DTOLFP(pp->offset, &ltmp);
				HTONL_FP(&ltmp, &ips->offset);
				ips->dispersion = HTONS_FP(DTOUFP(SQRT(pp->disp)));
			}	
			pp = pp->next; 
			ips = (struct info_peer_summary *)more_pkt();
		}
	}
	flush_pkt();
}


/*
 * peer_info - send information for one or more peers
 */
static void
peer_info (
	struct sockaddr_storage *srcadr,
	struct interface *inter,
	struct req_pkt *inpkt
	)
{
	register struct info_peer_list *ipl;
	register struct peer *pp;
	register struct info_peer *ip;
	register int items;
	register int i, j;
	struct sockaddr_storage addr;
	extern struct peer *sys_peer;
	l_fp ltmp;

	memset((char *)&addr, 0, sizeof addr);
	items = INFO_NITEMS(inpkt->err_nitems);
	ipl = (struct info_peer_list *) inpkt->data;

	ip = (struct info_peer *)prepare_pkt(srcadr, inter, inpkt,
	    v6sizeof(struct info_peer));
	while (items-- > 0 && ip != 0) {
		memset((char *)&addr, 0, sizeof(addr));
		NSRCPORT(&addr) = ipl->port;
		if (client_v6_capable && ipl->v6_flag != 0) {
			addr.ss_family = AF_INET6;
			GET_INADDR6(addr) = ipl->addr6;
		} else {
			addr.ss_family = AF_INET;
			GET_INADDR(addr) = ipl->addr;
		}
#ifdef HAVE_SA_LEN_IN_STRUCT_SOCKADDR
		addr.ss_len = SOCKLEN(&addr);
#endif
		ipl++;
		if ((pp = findexistingpeer(&addr, (struct peer *)0, -1)) == 0)
		    continue;
		if (pp->srcadr.ss_family == AF_INET6) {
			ip->dstadr6 = pp->cast_flags == MDF_BCAST ?
				GET_INADDR6(pp->dstadr->bcast) :
				GET_INADDR6(pp->dstadr->sin);
			ip->srcadr6 = GET_INADDR6(pp->srcadr);
			ip->v6_flag = 1;
		} else {
/* XXX PDM This code is buggy. Need to replace with a straightforward assignment */
			ip->dstadr = (pp->processed) ?
				pp->cast_flags == MDF_BCAST ?
				GET_INADDR(pp->dstadr->bcast):
				pp->cast_flags ?
				GET_INADDR(pp->dstadr->sin) ?
				GET_INADDR(pp->dstadr->sin):
				GET_INADDR(pp->dstadr->bcast):
				2 : GET_INADDR(pp->dstadr->sin);

			ip->srcadr = GET_INADDR(pp->srcadr);
			if (client_v6_capable)
				ip->v6_flag = 0;
		}
		ip->srcport = NSRCPORT(&pp->srcadr);
		ip->flags = 0;
		if (pp == sys_peer)
		    ip->flags |= INFO_FLAG_SYSPEER;
		if (pp->flags & FLAG_CONFIG)
		    ip->flags |= INFO_FLAG_CONFIG;
		if (pp->flags & FLAG_REFCLOCK)
		    ip->flags |= INFO_FLAG_REFCLOCK;
		if (pp->flags & FLAG_AUTHENABLE)
		    ip->flags |= INFO_FLAG_AUTHENABLE;
		if (pp->flags & FLAG_PREFER)
		    ip->flags |= INFO_FLAG_PREFER;
		if (pp->flags & FLAG_BURST)
		    ip->flags |= INFO_FLAG_BURST;
		if (pp->status == CTL_PST_SEL_SYNCCAND)
		    ip->flags |= INFO_FLAG_SEL_CANDIDATE;
		if (pp->status >= CTL_PST_SEL_SYSPEER)
		    ip->flags |= INFO_FLAG_SHORTLIST;
		ip->leap = pp->leap;
		ip->hmode = pp->hmode;
		ip->keyid = pp->keyid;
		ip->stratum = pp->stratum;
		ip->ppoll = pp->ppoll;
		ip->hpoll = pp->hpoll;
		ip->precision = pp->precision;
		ip->version = pp->version;
		ip->reach = pp->reach;
		ip->unreach = (u_char) pp->unreach;
		ip->flash = (u_char)pp->flash;
		ip->flash2 = (u_short) pp->flash;
		ip->estbdelay = HTONS_FP(DTOFP(pp->estbdelay));
		ip->ttl = pp->ttl;
		ip->associd = htons(pp->associd);
		ip->rootdelay = HTONS_FP(DTOUFP(pp->rootdelay));
		ip->rootdispersion = HTONS_FP(DTOUFP(pp->rootdispersion));
		ip->refid = pp->refid;
		HTONL_FP(&pp->reftime, &ip->reftime);
		HTONL_FP(&pp->org, &ip->org);
		HTONL_FP(&pp->rec, &ip->rec);
		HTONL_FP(&pp->xmt, &ip->xmt);
		j = pp->filter_nextpt - 1;
		for (i = 0; i < NTP_SHIFT; i++, j--) {
			if (j < 0)
			    j = NTP_SHIFT-1;
			ip->filtdelay[i] = HTONS_FP(DTOFP(pp->filter_delay[j]));
			DTOLFP(pp->filter_offset[j], &ltmp);
			HTONL_FP(&ltmp, &ip->filtoffset[i]);
			ip->order[i] = (u_char)((pp->filter_nextpt+NTP_SHIFT-1)
				- pp->filter_order[i]);
			if (ip->order[i] >= NTP_SHIFT)
			    ip->order[i] -= NTP_SHIFT;
		}
		DTOLFP(pp->offset, &ltmp);
		HTONL_FP(&ltmp, &ip->offset);
		ip->delay = HTONS_FP(DTOFP(pp->delay));
		ip->dispersion = HTONS_FP(DTOUFP(SQRT(pp->disp)));
		ip->selectdisp = HTONS_FP(DTOUFP(SQRT(pp->jitter)));
		ip = (struct info_peer *)more_pkt();
	}
	flush_pkt();
}


/*
 * peer_stats - send statistics for one or more peers
 */
static void
peer_stats (
	struct sockaddr_storage *srcadr,
	struct interface *inter,
	struct req_pkt *inpkt
	)
{
	register struct info_peer_list *ipl;
	register struct peer *pp;
	register struct info_peer_stats *ip;
	register int items;
	struct sockaddr_storage addr;
	extern struct peer *sys_peer;

#ifdef DEBUG
	if (debug)
	     printf("peer_stats: called\n");
#endif
	items = INFO_NITEMS(inpkt->err_nitems);
	ipl = (struct info_peer_list *) inpkt->data;
	ip = (struct info_peer_stats *)prepare_pkt(srcadr, inter, inpkt,
	    v6sizeof(struct info_peer_stats));
	while (items-- > 0 && ip != 0) {
		memset((char *)&addr, 0, sizeof(addr));
		NSRCPORT(&addr) = ipl->port;
		if (client_v6_capable && ipl->v6_flag) {
			addr.ss_family = AF_INET6;
			GET_INADDR6(addr) = ipl->addr6;
		} else {
			addr.ss_family = AF_INET;
			GET_INADDR(addr) = ipl->addr;
		}	
#ifdef HAVE_SA_LEN_IN_STRUCT_SOCKADDR
		addr.ss_len = SOCKLEN(&addr);
#endif
#ifdef DEBUG
		if (debug)
		    printf("peer_stats: looking for %s, %d, %d\n", stoa(&addr),
		    ipl->port, ((struct sockaddr_in6 *)&addr)->sin6_port);
#endif
		ipl = (struct info_peer_list *)((char *)ipl +
		    INFO_ITEMSIZE(inpkt->mbz_itemsize));

		if ((pp = findexistingpeer(&addr, (struct peer *)0, -1)) == 0)
		    continue;
#ifdef DEBUG
		if (debug)
		     printf("peer_stats: found %s\n", stoa(&addr));
#endif
		if (pp->srcadr.ss_family == AF_INET) {
			ip->dstadr = (pp->processed) ?
				pp->cast_flags == MDF_BCAST ?
				GET_INADDR(pp->dstadr->bcast):
				pp->cast_flags ?
				GET_INADDR(pp->dstadr->sin) ?
				GET_INADDR(pp->dstadr->sin):
				GET_INADDR(pp->dstadr->bcast):
				3 : 7;
			ip->srcadr = GET_INADDR(pp->srcadr);
			if (client_v6_capable)
				ip->v6_flag = 0;
		} else {
			ip->dstadr6 = pp->cast_flags == MDF_BCAST ?
				GET_INADDR6(pp->dstadr->bcast):
				GET_INADDR6(pp->dstadr->sin);
			ip->srcadr6 = GET_INADDR6(pp->srcadr);
			ip->v6_flag = 1;
		}	
		ip->srcport = NSRCPORT(&pp->srcadr);
		ip->flags = 0;
		if (pp == sys_peer)
		    ip->flags |= INFO_FLAG_SYSPEER;
		if (pp->flags & FLAG_CONFIG)
		    ip->flags |= INFO_FLAG_CONFIG;
		if (pp->flags & FLAG_REFCLOCK)
		    ip->flags |= INFO_FLAG_REFCLOCK;
		if (pp->flags & FLAG_AUTHENABLE)
		    ip->flags |= INFO_FLAG_AUTHENABLE;
		if (pp->flags & FLAG_PREFER)
		    ip->flags |= INFO_FLAG_PREFER;
		if (pp->flags & FLAG_BURST)
		    ip->flags |= INFO_FLAG_BURST;