Fix a bug in dns_catz_generate_zonecfg()

The dns_catz_generate_zonecfg() function generates a zone configuration
string to use with a new catalog zone member zone. The buffer for the
string is 512 bytes initially (ISC_BUFFER_INCR), but can be reallocated
when required, when using corresponding isc_buffer functions like
isc_buffer_reserve(), isc_buffer_putstr(), isc_buffer_copyregion(), etc.

However, the dns_name_totext() function, which expects the buffer as an
argument, doesn't automatically resize it if the name doesn't fit there,
but instead just returns ISC_R_NOSPACE.

The chance of this occurring increases when the configuration string is
large due to, for example, long zone name, long list of primary servers
which have keys configured and/or TLS configured.

Use dns_name_format() accompanied with isc_buffer_putstr() instead of
dns_name_totext().

diff --git a/lib/dns/catz.c b/lib/dns/catz.c
index 198e68ad6db71026fa56b4e5f840fc8fbdcd7617..305296b02047ccfa201a723930c339c5ade016c2 100644 (file)
--- a/lib/dns/catz.c
+++ b/lib/dns/catz.c
@@ -1913,7 +1913,7 @@ dns_catz_generate_zonecfg(dns_catz_zone_t *catz, dns_catz_entry_t *entry,
        uint32_t i;
        isc_netaddr_t netaddr;
        char pbuf[sizeof("65535")]; /* used for port number */
-       char zname[DNS_NAME_FORMATSIZE];
+       char namebuf[DNS_NAME_FORMATSIZE];
 
        REQUIRE(DNS_CATZ_ZONE_VALID(catz));
        REQUIRE(DNS_CATZ_ENTRY_VALID(entry));
@@ -1926,7 +1926,8 @@ dns_catz_generate_zonecfg(dns_catz_zone_t *catz, dns_catz_entry_t *entry,
        isc_buffer_allocate(catz->catzs->mctx, &buffer, ISC_BUFFER_INCR);
 
        isc_buffer_putstr(buffer, "zone \"");
-       dns_name_totext(&entry->name, DNS_NAME_OMITFINALDOT, buffer);
+       dns_name_format(&entry->name, namebuf, sizeof(namebuf));
+       isc_buffer_putstr(buffer, namebuf);
        isc_buffer_putstr(buffer, "\" { type secondary; primaries");
 
        isc_buffer_putstr(buffer, " { ");
@@ -1939,13 +1940,12 @@ dns_catz_generate_zonecfg(dns_catz_zone_t *catz, dns_catz_entry_t *entry,
                case AF_INET6:
                        break;
                default:
-                       dns_name_format(&entry->name, zname,
-                                       DNS_NAME_FORMATSIZE);
+                       dns_name_format(&entry->name, namebuf, sizeof(namebuf));
                        isc_log_write(DNS_LOGCATEGORY_GENERAL,
                                      DNS_LOGMODULE_CATZ, ISC_LOG_ERROR,
                                      "catz: zone '%s' uses an invalid primary "
                                      "(no IP address assigned)",
-                                     zname);
+                                     namebuf);
                        CLEANUP(ISC_R_FAILURE);
                }
                isc_netaddr_fromsockaddr(&netaddr,
@@ -1961,14 +1961,16 @@ dns_catz_generate_zonecfg(dns_catz_zone_t *catz, dns_catz_entry_t *entry,
 
                if (entry->opts.masters.keys[i] != NULL) {
                        isc_buffer_putstr(buffer, " key ");
-                       CHECK(dns_name_totext(entry->opts.masters.keys[i],
-                                             DNS_NAME_OMITFINALDOT, buffer));
+                       dns_name_format(entry->opts.masters.keys[i], namebuf,
+                                       sizeof(namebuf));
+                       isc_buffer_putstr(buffer, namebuf);
                }
 
                if (entry->opts.masters.tlss[i] != NULL) {
                        isc_buffer_putstr(buffer, " tls ");
-                       CHECK(dns_name_totext(entry->opts.masters.tlss[i],
-                                             DNS_NAME_OMITFINALDOT, buffer));
+                       dns_name_format(entry->opts.masters.tlss[i], namebuf,
+                                       sizeof(namebuf));
+                       isc_buffer_putstr(buffer, namebuf);
                }
                isc_buffer_putstr(buffer, "; ");
        }