res_findzonecut.c

bind 9.3结合mysql数据库

				DPRINTF(("get_soa: zname(%d) too small (%d)",
					 zsize, strlen(t) + 1));
				errno = EMSGSIZE;
				goto cleanup;
			}
			strcpy(zname, t);
			rdata = ns_rr_rdata(rr);
			rdlen = ns_rr_rdlen(rr);
			if (ns_name_uncompress(resp, ns_msg_end(msg), rdata,
					       mname, msize) < 0) {
				DPRINTF(("get_soa: ns_name_uncompress failed")
					);
				goto cleanup;
			}
			if (save_ns(statp, &msg, ns_s_ns,
				    zname, class, opts, nsrrsp) < 0) {
				DPRINTF(("get_soa: save_ns failed"));
				goto cleanup;
			}
			free(resp);
			return (0);
		}

		/* If we're out of labels, then not even "." has an SOA! */
		if (*dname == '\0')
			break;

		/* Find label-terminating "."; top of loop will skip it. */
		while (*dname != '.') {
			if (*dname == '\\')
				if (*++dname == '\0') {
					errno = EMSGSIZE;
					goto cleanup;
				}
			dname++;
		}
	}
	DPRINTF(("get_soa: out of labels"));
	errno = EDESTADDRREQ;
 cleanup:
	if (resp != NULL)
		free(resp);
	return (-1);
}

static int
get_ns(res_state statp, const char *zname, ns_class class, int opts,
      rrset_ns *nsrrsp)
{
	u_char *resp;
	ns_msg msg;
	int n;

	resp = malloc(NS_MAXMSG);
	if (resp == NULL)
		return (-1);

	/* Go and get the NS RRs for this zone. */
	n = do_query(statp, zname, class, ns_t_ns, resp, &msg);
	if (n != 0) {
		DPRINTF(("get_ns: do_query('%s', %s) failed (%d)",
			 zname, p_class(class), n));
		free(resp);
		return (-1);
	}

	/* Remember the NS RRs and associated A RRs that came back. */
	if (save_ns(statp, &msg, ns_s_an, zname, class, opts, nsrrsp) < 0) {
		DPRINTF(("get_ns save_ns('%s', %s) failed",
			 zname, p_class(class)));
		free(resp);
		return (-1);
	}

	free(resp);
	return (0);
}

static int
get_glue(res_state statp, ns_class class, int opts, rrset_ns *nsrrsp) {
	rr_ns *nsrr, *nsrr_n;
	u_char *resp;

	resp = malloc(NS_MAXMSG);
	if (resp == NULL)
		return(-1);

	/* Go and get the A RRs for each empty NS RR on our list. */
	for (nsrr = HEAD(*nsrrsp); nsrr != NULL; nsrr = nsrr_n) {
		ns_msg msg;
		int n;

		nsrr_n = NEXT(nsrr, link);

		if ((nsrr->flags & RR_NS_HAVE_V4) == 0) {
			n = do_query(statp, nsrr->name, class, ns_t_a,
				     resp, &msg);
			if (n < 0) {
				DPRINTF(
				       ("get_glue: do_query('%s', %s') failed",
					nsrr->name, p_class(class)));
				goto cleanup;
			}
			if (n > 0) {
				DPRINTF((
			"get_glue: do_query('%s', %s') CNAME or DNAME found",
					 nsrr->name, p_class(class)));
			}
			if (save_a(statp, &msg, ns_s_an, nsrr->name, class,
				   opts, nsrr) < 0) {
				DPRINTF(("get_glue: save_r('%s', %s) failed",
					 nsrr->name, p_class(class)));
				goto cleanup;
			}
		}

		if ((nsrr->flags & RR_NS_HAVE_V6) == 0) {
			n = do_query(statp, nsrr->name, class, ns_t_aaaa,
				     resp, &msg);
			if (n < 0) {
				DPRINTF(
				       ("get_glue: do_query('%s', %s') failed",
					nsrr->name, p_class(class)));
				goto cleanup;
			}
			if (n > 0) {
				DPRINTF((
			"get_glue: do_query('%s', %s') CNAME or DNAME found",
					 nsrr->name, p_class(class)));
			}
			if (save_a(statp, &msg, ns_s_an, nsrr->name, class,
				   opts, nsrr) < 0) {
				DPRINTF(("get_glue: save_r('%s', %s) failed",
					 nsrr->name, p_class(class)));
				goto cleanup;
			}
		}

		/* If it's still empty, it's just chaff. */
		if (EMPTY(nsrr->addrs)) {
			DPRINTF(("get_glue: removing empty '%s' NS",
				 nsrr->name));
			free_nsrr(nsrrsp, nsrr);
		}
	}
	free(resp);
	return (0);

 cleanup:
	free(resp);
	return (-1);
}

static int
save_ns(res_state statp, ns_msg *msg, ns_sect sect,
	const char *owner, ns_class class, int opts,
	rrset_ns *nsrrsp)
{
	int i;

	for (i = 0; i < ns_msg_count(*msg, sect); i++) {
		char tname[MAXDNAME];
		const u_char *rdata;
		rr_ns *nsrr;
		ns_rr rr;
		int rdlen;

		if (ns_parserr(msg, sect, i, &rr) < 0) {
			DPRINTF(("save_ns: ns_parserr(%s, %d) failed",
				 p_section(sect, ns_o_query), i));
			return (-1);
		}
		if (ns_rr_type(rr) != ns_t_ns ||
		    ns_rr_class(rr) != class ||
		    ns_samename(ns_rr_name(rr), owner) != 1)
			continue;
		nsrr = find_ns(nsrrsp, ns_rr_name(rr));
		if (nsrr == NULL) {
			nsrr = malloc(sizeof *nsrr);
			if (nsrr == NULL) {
				DPRINTF(("save_ns: malloc failed"));
				return (-1);
			}
			rdata = ns_rr_rdata(rr);
			rdlen = ns_rr_rdlen(rr);
			if (ns_name_uncompress(ns_msg_base(*msg),
					       ns_msg_end(*msg), rdata,
					       tname, sizeof tname) < 0) {
				DPRINTF(("save_ns: ns_name_uncompress failed")
					);
				free(nsrr);
				return (-1);
			}
			nsrr->name = strdup(tname);
			if (nsrr->name == NULL) {
				DPRINTF(("save_ns: strdup failed"));
				free(nsrr);
				return (-1);
			}
			INIT_LINK(nsrr, link);
			INIT_LIST(nsrr->addrs);
			nsrr->flags = 0;
			APPEND(*nsrrsp, nsrr, link);
		}
		if (save_a(statp, msg, ns_s_ar,
			   nsrr->name, class, opts, nsrr) < 0) {
			DPRINTF(("save_ns: save_r('%s', %s) failed",
				 nsrr->name, p_class(class)));
			return (-1);
		}
	}
	return (0);
}

static int
save_a(res_state statp, ns_msg *msg, ns_sect sect,
       const char *owner, ns_class class, int opts,
       rr_ns *nsrr)
{
	int i;

	for (i = 0; i < ns_msg_count(*msg, sect); i++) {
		ns_rr rr;
		rr_a *arr;

		if (ns_parserr(msg, sect, i, &rr) < 0) {
			DPRINTF(("save_a: ns_parserr(%s, %d) failed",
				 p_section(sect, ns_o_query), i));
			return (-1);
		}
		if ((ns_rr_type(rr) != ns_t_a &&
		     ns_rr_type(rr) != ns_t_aaaa) ||
		    ns_rr_class(rr) != class ||
		    ns_samename(ns_rr_name(rr), owner) != 1 ||
		    ns_rr_rdlen(rr) != NS_INADDRSZ)
			continue;
		if ((opts & RES_IPV6ONLY) != 0 && ns_rr_type(rr) != ns_t_aaaa)
			continue;
		if ((opts & RES_IPV4ONLY) != 0 && ns_rr_type(rr) != ns_t_a)
			continue;
		arr = malloc(sizeof *arr);
		if (arr == NULL) {
			DPRINTF(("save_a: malloc failed"));
			return (-1);
		}
		INIT_LINK(arr, link);
		memset(&arr->addr, 0, sizeof(arr->addr));
		switch (ns_rr_type(rr)) {
		case ns_t_a:
			arr->addr.sin.sin_family = AF_INET;
#ifdef HAVE_SA_LEN
			arr->addr.sin.sin_len = sizeof(arr->addr.sin);
#endif
			memcpy(&arr->addr.sin.sin_addr, ns_rr_rdata(rr),
			       NS_INADDRSZ);
			arr->addr.sin.sin_port = htons(NAMESERVER_PORT);
			nsrr->flags |= RR_NS_HAVE_V4;
			break;
		case ns_t_aaaa:
			arr->addr.sin6.sin6_family = AF_INET6;
#ifdef HAVE_SA_LEN
			arr->addr.sin6.sin6_len = sizeof(arr->addr.sin6);
#endif
			memcpy(&arr->addr.sin6.sin6_addr, ns_rr_rdata(rr), 16);
			arr->addr.sin.sin_port = htons(NAMESERVER_PORT);
			nsrr->flags |= RR_NS_HAVE_V6;
			break;
		default:
			abort();
		}
		APPEND(nsrr->addrs, arr, link);
	}
	return (0);
}

static void
free_nsrrset(rrset_ns *nsrrsp) {
	rr_ns *nsrr;

	while ((nsrr = HEAD(*nsrrsp)) != NULL)
		free_nsrr(nsrrsp, nsrr);
}

static void
free_nsrr(rrset_ns *nsrrsp, rr_ns *nsrr) {
	rr_a *arr;
	char *tmp;

	while ((arr = HEAD(nsrr->addrs)) != NULL) {
		UNLINK(nsrr->addrs, arr, link);
		free(arr);
	}
	DE_CONST(nsrr->name, tmp);
	free(tmp);
	UNLINK(*nsrrsp, nsrr, link);
	free(nsrr);
}

static rr_ns *
find_ns(rrset_ns *nsrrsp, const char *dname) {
	rr_ns *nsrr;

	for (nsrr = HEAD(*nsrrsp); nsrr != NULL; nsrr = NEXT(nsrr, link))
		if (ns_samename(nsrr->name, dname) == 1)
			return (nsrr);
	return (NULL);
}

static int
do_query(res_state statp, const char *dname, ns_class class, ns_type qtype,
	 u_char *resp, ns_msg *msg)
{
	u_char req[NS_PACKETSZ];
	int i, n;

	n = res_nmkquery(statp, ns_o_query, dname, class, qtype,
			 NULL, 0, NULL, req, NS_PACKETSZ);
	if (n < 0) {
		DPRINTF(("do_query: res_nmkquery failed"));
		return (-1);
	}
	n = res_nsend(statp, req, n, resp, NS_MAXMSG);
	if (n < 0) {
		DPRINTF(("do_query: res_nsend failed"));
		return (-1);
	}
	if (n == 0) {
		DPRINTF(("do_query: res_nsend returned 0"));
		errno = EMSGSIZE;
		return (-1);
	}
	if (ns_initparse(resp, n, msg) < 0) {
		DPRINTF(("do_query: ns_initparse failed"));
		return (-1);
	}
	n = 0;
	for (i = 0; i < ns_msg_count(*msg, ns_s_an); i++) {
		ns_rr rr;

		if (ns_parserr(msg, ns_s_an, i, &rr) < 0) {
			DPRINTF(("do_query: ns_parserr failed"));
			return (-1);
		}
		n += (ns_rr_class(rr) == class &&
		      (ns_rr_type(rr) == ns_t_cname ||
		       ns_rr_type(rr) == ns_t_dname));
	}
	return (n);
}

static void
res_dprintf(const char *fmt, ...) {
	va_list ap;

	va_start(ap, fmt);
	fputs(";; res_findzonecut: ", stderr);
	vfprintf(stderr, fmt, ap);
	fputc('\n', stderr);
	va_end(ap);
}