ns_validate.c

早期freebsd实现

		free(nameaddrlist[firstNA].nsname);
		nameaddrlist[firstNA].nsname = 0;
		lastNA = (lastNA+1) % MAXNAMECACHE;
	}
	return;
}

/*
 * Decode the resource record 'rrp' and validate the RR.
 * Borrows code almost entirely from doupdate(). is a rather
 * non-invasive routine since it just goes thru the same motions
 * as doupdate but just marks the array validatelist entry as 
 * the return code from validate(). This is later used in doupdate
 * to cache/not cache the entry. also used in update_msg() to 
 * delete/keep the record from the outgoing message.
 */
int
dovalidate(msg, msglen, rrp, zone, flags, server, VCode)
	char *msg;
	u_char *rrp;
	int  msglen, zone, flags;
	struct sockaddr_in *server;
	int *VCode;
{
	register u_char *cp;
	register int n;
	int class, type, dlen, n1;
	u_int32_t ttl;
	char dname[MAXDNAME];
	u_char *cp1;
	u_char data[BUFSIZ];
	register HEADER *hp = (HEADER *) msg;

	dprintf(2, (ddt, "dovalidate(zone %d, flags %x)\n",
		    zone, flags));
#ifdef DEBUG
	if(debug >= 10)
		fp_query((char *)msg,ddt);
#endif

	cp = rrp;
	if ((n = dn_expand((u_char *)msg, (u_char *)msg + msglen, cp,
			   (u_char *)dname, sizeof(dname))) < 0) {
		hp->rcode = FORMERR;
		return (-1);
	}
	cp += n;
	GETSHORT(type, cp);
	GETSHORT(class, cp);
	GETLONG(ttl, cp);
	GETSHORT(dlen, cp);
	dprintf(2, (ddt, "dovalidate: dname %s type %d class %d ttl %d\n",
		    dname, type, class, ttl));
	/*
	 * Convert the resource record data into the internal
	 * database format.
	 */
	switch (type) {
	case T_A:
	case T_WKS:
	case T_HINFO:
	case T_UINFO:
	case T_UID:
	case T_GID:
	case T_TXT:
#ifdef ALLOW_T_UNSPEC
	case T_UNSPEC:
#endif
		cp1 = cp;
		n = dlen;
		cp += n;
		break;

	case T_CNAME:
	case T_MB:
	case T_MG:
	case T_MR:
	case T_NS:
	case T_PTR:
		if ((n = dn_expand((u_char *)msg, (u_char *)msg + msglen,
				   cp, data, sizeof(data))) < 0) {
			hp->rcode = FORMERR;
			return (-1);
		}
		cp += n;
		cp1 = data;
		n = strlen((char *)data) + 1;
		break;

	case T_MINFO:
	case T_SOA:
	case T_RP:
		if ((n = dn_expand((u_char *)msg, (u_char *)msg + msglen,
				   cp, data, sizeof(data))) < 0) {
			hp->rcode = FORMERR;
			return (-1);
		}
		cp += n;
		cp1 = data + (n = strlen((char *)data) + 1);
		n1 = sizeof(data) - n;
		if (type == T_SOA)
			n1 -= 5 * sizeof(u_int32_t);
		if ((n = dn_expand((u_char *)msg, (u_char *)msg + msglen,
				   cp, cp1, n1)) < 0) {
			hp->rcode = FORMERR;
			return (-1);
		}
		cp += n;
		cp1 += strlen((char *)cp1) + 1;
		if (type == T_SOA) {
			bcopy((char *)cp, (char *)cp1, n = 5 * sizeof(u_int32_t));
			cp += n;
			cp1 += n;
		}
		n = cp1 - data;
		cp1 = data;
		break;

	case T_MX:
	case T_AFSDB:
		/* grab preference */
		bcopy((char *)cp, data, sizeof(u_int16_t));
		cp1 = data + sizeof(u_int16_t);
		cp += sizeof(u_int16_t);

		/* get name */
		if ((n = dn_expand((u_char *)msg, (u_char *)msg + msglen,
				   cp, cp1, sizeof(data) - sizeof(u_int16_t)))
		    < 0) {
			hp->rcode = FORMERR;
			return(-1);
		}
		cp += n;

		/* compute end of data */
		cp1 += strlen((char *)cp1) + 1;
		/* compute size of data */
		n = cp1 - data;
		cp1 = data;
		break;

	default:
		dprintf(3, (ddt, "unknown type %d\n", type));
		return ((cp - rrp) + dlen);
	}
	if (n > MAXDATA) {
		dprintf(2, (ddt,
			    "update type %d: %d bytes is too much data\n",
			    type, n));
		hp->rcode = NOCHANGE;	/* XXX - FORMERR ??? */
		return(-1);
	}

	*VCode = validate(dname, server, type, class,(char *)cp1, n
#ifdef NCACHE
			  ,NOERROR
#endif
			  );
	if (*VCode == INVALID) {
		dprintf(2, (ddt,
			    "validation failed d:%s, t:%d, c:%d\n",
			    dname, type, class));
	} else {
		dprintf(2, (ddt,
			    "validation succeeded d:%s, t:%d, c:%d\n",
			    dname, type, class));
	}
	return(cp -rrp);
}

/******************************************************************
  * This manages a data structure that stores all RRs that we were
  * unable to validate. Am not sure exactly what purpose this might
  * serve but until such time as we are sure it will not help, let
  * me do it anyway.
  *****************************************************************/
static void
stick_in_queue(dname, type, class, data)
	char *dname;
	int type;
	int class;
	char *data;
{
	struct timeval tp;
	struct timezone tzp;
	TO_Validate *tempVQ;
	u_long leasttime;

	if (validateQ == NULL) {
		validateQ = (TO_Validate *)malloc(sizeof(TO_Validate));
		validateQ->type = type;
		validateQ->class = class;
		validateQ->dname = malloc((unsigned)strlen(dname)+1);
		strcpy(validateQ->dname, dname);
		validateQ->data = malloc((unsigned)strlen(data)+1);
		strcpy(validateQ->data, data);
		gettimeofday(&tp, &tzp);
		validateQ->time = tp.tv_sec;
		VQcount = 1;
		validateQ->next = validateQ->prev = NULL;
		currentVQ = validateQ;
		return;
	}
	if (VQcount < MAXVQ) {
		tempVQ =(TO_Validate *)malloc(sizeof(TO_Validate));
		tempVQ->type = type;
		tempVQ->class = class;
		tempVQ->dname = malloc((unsigned)strlen(dname)+1);
		strcpy(tempVQ->dname, dname);
		tempVQ->data = malloc((unsigned)strlen(data)+1);
		strcpy(tempVQ->data, data);
		gettimeofday(&tp,&tzp);
		tempVQ->time = tp.tv_sec;
		tempVQ->next = currentVQ->next;
		tempVQ->prev = currentVQ;
		if (currentVQ->next != NULL)
			currentVQ->next->prev = tempVQ;
		currentVQ->next = tempVQ;
		currentVQ = tempVQ;
		VQcount++;
		return;
	}
	gettimeofday(&tp, &tzp);
	leasttime = validateQ->time;
	currentVQ = validateQ;
	for (tempVQ = validateQ;  tempVQ != NULL;  tempVQ = tempVQ->next) {
		if (tp.tv_sec >= tempVQ->time +VQEXPIRY) {
			tempVQ->type = type;
			tempVQ->class = class;
			strcpy(tempVQ->dname, dname);
			strcpy(tempVQ->data, data);
			tempVQ->time = tp.tv_sec;
			currentVQ = tempVQ;
			return;
		}
		if (tempVQ->time < leasttime) {
			leasttime = tempVQ->time;
			currentVQ = tempVQ;
		}
	}
	currentVQ->type = type;
	currentVQ->class = class;
	strcpy(currentVQ->dname, dname);
	strcpy(currentVQ->data, data);
	currentVQ->time = tp.tv_sec;
	return;
}

/* removes any INVALID RR's from the msg being returned, updates msglen to
 * reflect the new message length.
 */
int
update_msg(msg, msglen, Vlist, c)
	u_char *msg;
	int *msglen;
	int Vlist[];
	int c;
{
	register HEADER *hp;
	register u_char *cp;
	int i;
	int n = 0;
	u_char *tempcp, *newcp;
	int *RRlen;
	int qlen; /* the length of the query section*/
	u_int16_t rdlength;
	u_int16_t ancount, nscount;
	u_int16_t new_ancount, new_nscount, new_arcount;
	char dname[MAXDNAME], qname[MAXDNAME];
	u_char data[MAXDNAME];
	u_char **dpp;
	u_char *dnptrs[40];
	u_char **edp = dnptrs + sizeof(dnptrs)/sizeof(dnptrs[0]);
	u_char *eom = msg + *msglen;
	int n_new;
	int rembuflen, newlen;
	u_char *newmsg;
	u_int16_t type, class, dlen;
	u_int32_t ttl;
	int inv = 0;

#ifdef DEBUG
	if (debug) {
		fprintf(ddt, "update_msg: msglen:%d, c:%d\n", *msglen, c);
		if (debug >= 10)
			fp_query((char *)msg,ddt);
	}
#endif
	/* just making sure we do not do all the work for nothing */
	for (i=0;  i<c;  i++) { 
		if (Vlist[i] == INVALID) {
			inv = 1;
			break;
		}
	}
	if (inv != 1) {
		/* no invalid records, go about your job */
		return (0);
	}

	dprintf(2, (ddt, "update_msg: NEEDS updating:\n"));

	RRlen = (int *)malloc((unsigned)c*sizeof(int));
	hp = (HEADER *)msg;
	new_ancount = ancount = ntohs(hp->ancount);
	new_nscount = nscount = ntohs(hp->nscount);
	new_arcount = ntohs(hp->nscount);

	cp = msg + sizeof(HEADER);
	newlen = sizeof(HEADER);
	/* skip the query section */
	qlen = dn_expand(msg, eom, cp, (u_char *)qname, sizeof(qname));
	if (qlen <= 0) {
		dprintf(2, (ddt, "dn_skipname() failed, bad record\n"));
		goto badend;
	}
	cp +=qlen;
	GETSHORT(type,cp);
	GETSHORT(class,cp);
	qlen += 2 * sizeof(u_int16_t);
	newlen += qlen;

	for (i = 0;  i < c;  i++) {
		if (Vlist[i] == INVALID) {
			if (i < ancount)
				new_ancount--;
			else if (i < ancount+nscount)
				new_nscount--;
			else
				new_arcount--;
		}

		RRlen[i] = dn_skipname(cp, msg + *msglen);
		if (RRlen[i] <= 0) {
			dprintf(2, (ddt,
				    "dn_skipname() failed, bad record\n"));
			goto badend;
		}
		RRlen[i] += 2 * sizeof(u_int16_t) + sizeof(u_int32_t);
				/*type+class+TTL*/
		cp += RRlen[i];
		GETSHORT(rdlength, cp);
		RRlen[i] += sizeof(u_int16_t); /*rdlength*/
		RRlen[i] += rdlength; /*rdata field*/
		dprintf(3, (ddt, "RRlen[%d]=%d\n", i, RRlen[i]));
		if (Vlist[i] != INVALID)
			newlen += RRlen[i];
		cp += rdlength; /*increment pointer to next RR*/
	}
	hp->ancount = htons(new_ancount);
	hp->nscount = htons(new_nscount);
	hp->arcount = htons(new_nscount);
	/* get new buffer */
	dprintf(3, (ddt,
		    "newlen:%d, if no RR is INVALID == msglen\n", newlen));
	newmsg = (u_char *)calloc(1,newlen + MAXDNAME);
	if(newmsg == NULL)
		goto badend;
	dpp = dnptrs;
	*dpp++ = newmsg;
	*dpp = NULL;
	/* bcopy the header, with all the length fields correctly put in */
	bcopy((char *)msg, (char*)newmsg, sizeof(HEADER)); /*header copied */
	newcp = newmsg +sizeof(HEADER);  /*need a pointer in the new buffer */
	rembuflen = newlen +MAXDNAME - sizeof(HEADER); /*buflen we can workin*/
	newlen = sizeof(HEADER); /* this will now contain the length of msg */
	n_new = dn_comp((u_char *)qname, (u_char *)newcp, rembuflen,
			(u_char **)dnptrs, (u_char **)edp);
	if (n_new < 0)
		goto badend;
	newcp += n_new;
	PUTSHORT(type, newcp);
	PUTSHORT(class, newcp); /*query section complete*/
	newlen += (n_new+2*sizeof(u_int16_t));
	rembuflen -= (n_new+2*sizeof(u_int16_t));
	/* have to decode and copy every Valid RR from here */
  
	cp = msg +sizeof(HEADER) +qlen;	/*skip header and query section*/
	for (i = 0;  i < c;  i++) {
		if (Vlist[i] == INVALID) {
			/* go to next RR if this one is not INVALID */
			cp += RRlen[i];
			continue;
		}
		/* we have a valid record, must put it in the newmsg */
		if ((n = dn_expand((u_char *)msg, eom, cp,
				   (u_char *)dname, sizeof(dname))) < 0) {
			hp->rcode = FORMERR;
			goto badend;
		}
		n_new = dn_comp((u_char *)dname, (u_char *)newcp, rembuflen,
				(u_char **)dnptrs, (u_char **)edp); 
		if (n_new < 0)
			goto badend;
		cp += n;
		newcp += n_new;
		dprintf(5, (ddt,
			    "cp:0x%x newcp:0x%x after getting name\n",
			    cp, newcp));
		GETSHORT(type, cp);
		PUTSHORT(type, newcp);
		dprintf(5, (ddt,
			    "cp:0x%x newcp:0x%x after getting type\n",
			    cp, newcp));
		GETSHORT(class, cp);
		PUTSHORT(class, newcp);
		dprintf(5, (ddt,
			    "cp:0x%x newcp:0x%x after getting class\n",
			    cp, newcp));
		GETLONG(ttl, cp);
		PUTLONG(ttl, newcp);
		dprintf(5, (ddt,
			    "cp:0x%x newcp:0x%x after getting ttl\n",
			    cp, newcp));
		/* this will probably be modified for newmsg,
		 * will put this in later, after compression
		 */
		GETSHORT(dlen, cp);
		newlen += (n_new+3*sizeof(u_int16_t) + sizeof(u_int32_t));
		rembuflen -= (n_new+3*sizeof(u_int16_t)+ sizeof(u_int32_t));
		tempcp = newcp;
		newcp += sizeof(u_int16_t); /*advance to rdata field*/
		dprintf(5, (ddt, "tempcp:0x%x newcp:0x%x\n",
			    tempcp, newcp));
		dprintf(3, (ddt,
			    "update_msg: dname %s type %d class %d ttl %d\n",
			    dname, type, class, ttl));
		/* read off the data section */
		switch (type) {
		case T_A:
		case T_WKS:
		case T_HINFO:
		case T_UINFO:
		case T_UID:
		case T_GID:
		case T_TXT:
#ifdef ALLOW_T_UNSPEC
		case T_UNSPEC:
#endif
			n = dlen;
			PUTSHORT(n, tempcp); /*time to put in the dlen*/
			bcopy(cp, newcp,n); /*done here*/
			cp +=n;
			newcp +=n;
			newlen += n;
			rembuflen -= n;
			dprintf(3, (ddt, "\tcp:0x%x newcp:0x%x dlen:%d\n",
				    cp, newcp, dlen));
			break;

		case T_CNAME:
		case T_MB:
		case T_MG:
		case T_MR:
		case T_NS:
		case T_PTR:
			 /*read off name from data section */
			if ((n = dn_expand((u_char *)msg, eom,
					   cp, data, sizeof(data))) < 0) {
				hp->rcode = FORMERR;
				goto badend;
			}
			cp += n; /*advance pointer*/
			/* fill in new packet */
			n_new = dn_comp((u_char *)data, (u_char *)newcp,
					rembuflen,
					(u_char **)dnptrs, (u_char **)edp);
			if (n_new < 0)
				goto badend;
			PUTSHORT(n_new,tempcp);	/*put in dlen field*/
			newcp += n_new; /*advance new pointer*/
			newlen += n_new;
			rembuflen -= n_new;
			break;

		case T_MINFO:
		case T_SOA:
		case T_RP:
			if ((n = dn_expand((u_char *)msg, eom, cp,
					   data, sizeof(data))) < 0) {
				hp->rcode = FORMERR;
				goto badend;
			}
			cp += n;
			n_new = dn_comp((u_char *)data, (u_char *)newcp,
					rembuflen,
					(u_char **)dnptrs, (u_char **)edp);
			if (n_new < 0)
				goto badend;
			newcp += n_new;
			newlen += n_new;
			rembuflen -= n_new;
			dlen = n_new;
			if ((n = dn_expand((u_char *)msg, eom, cp,
					   data, sizeof(data))) < 0) {
				hp->rcode = FORMERR;
				goto badend;
			}
			cp += n;
			n_new = dn_comp((u_char *)data, (u_char *)newcp,
					rembuflen,
					(u_char **)dnptrs, (u_char **)edp);
			if (n_new < 0)
				goto badend;
			newcp += n_new;
			newlen += n_new;
			rembuflen -= n_new;
			dlen += n_new;
			if (type == T_SOA) {
				bcopy(cp, newcp, n = 5*sizeof(u_int32_t));
				cp += n;
				newcp += n;
				newlen +=n;
				rembuflen -= n;
				dlen +=n;
			}
			PUTSHORT(dlen, tempcp);
			break;

		case T_MX:
		case T_AFSDB:
			/* grab preference */
			bcopy(cp,newcp,sizeof(u_int16_t));
			cp += sizeof(u_int16_t);
			newcp += sizeof(u_int16_t);
		
			/* get name */
			if ((n = dn_expand((u_char *)msg, eom, cp,
					   data, sizeof(data))) < 0) {
				hp->rcode = FORMERR;
				goto badend;
			}
			cp += n;
			n_new = dn_comp((u_char *)data, (u_char *)newcp,
					rembuflen,
					(u_char **)dnptrs, (u_char **)edp);
			if (n_new < 0)
				goto badend;
			PUTSHORT(n_new+sizeof(u_int16_t), tempcp);
			newcp += n_new;
			newlen += n_new+sizeof(u_int16_t);
			rembuflen -= n_new+sizeof(u_int16_t);
			break;

		default:
			dprintf(3, (ddt, "unknown type %d\n", type));
			goto badend;
		}
		dprintf(2, (ddt,
			    "newlen:%d, i:%d newcp:0x%x cp:0x%x\n\n",
			    newlen, i, newcp, cp));
	}
	bcopy(newmsg, msg, newlen);
	n = *msglen - newlen;
	if (n < 0) {
		dprintf(2, (ddt,
			"update_msg():newmsg longer than old: n:%d o:%d ???\n",
			    newlen, *msglen));
	}
	*msglen = newlen;
	free((char *)newmsg);
  
#ifdef DEBUG
	if (debug >= 10)
		fp_query((char *)msg, ddt);
#endif
	free((char *)RRlen);
	return(n);
badend:
	dprintf(2, (ddt, "encountered problems: UPDATE_MSG\n"));
	free((char *)RRlen);
	return(-1);
}

#endif /*VALIDATE*/