Ensure keyname buffer is big enough

Use a temporary string rather than a fixed buffer to construct
the keyname.

diff --git a/lib/isccfg/check.c b/lib/isccfg/check.c
index 2dcead8ec74cacc23180b79806bd92f62b57ee65..05fcddee6c3696cfb3d2cbd7fd48c8c04932df97 100644 (file)
--- a/lib/isccfg/check.c
+++ b/lib/isccfg/check.c
@@ -3236,12 +3236,17 @@ check_zoneconf(const cfg_obj_t *zconfig, const cfg_obj_t *voptions,
                            "zone '%s': is not a valid name", znamestr);
                result = ISC_R_FAILURE;
        } else {
-               char namebuf[DNS_NAME_FORMATSIZE + 128];
-               char *tmp = namebuf;
-               size_t len = sizeof(namebuf);
+               char namebuf[DNS_NAME_FORMATSIZE];
+               char classbuf[DNS_RDATACLASS_FORMATSIZE];
+               char *key = NULL;
+               const char *vname = NULL;
+               size_t len = 0;
+               int n;
 
                zname = dns_fixedname_name(&fixedname);
                dns_name_format(zname, namebuf, sizeof(namebuf));
+               dns_rdataclass_format(zclass, classbuf, sizeof(classbuf));
+
                tresult = exists(
                        zconfig, namebuf,
                        ztype == CFG_ZONE_HINT       ? 1
@@ -3260,15 +3265,16 @@ check_zoneconf(const cfg_obj_t *zconfig, const cfg_obj_t *voptions,
                } else if (dns_name_isula(zname)) {
                        ula = true;
                }
-               len -= strlen(tmp);
-               tmp += strlen(tmp);
-               (void)snprintf(tmp, len, "%u/%s", zclass,
-                              (ztype == CFG_ZONE_INVIEW) ? target
-                              : (viewname != NULL)       ? viewname
-                                                         : "_default");
+               vname = (ztype == CFG_ZONE_INVIEW) ? target
+                       : (viewname != NULL)       ? viewname
+                                                  : "_default";
+               len = strlen(namebuf) + strlen(classbuf) + strlen(vname) + 3;
+               key = isc_mem_get(mctx, len);
+               n = snprintf(key, len, "%s/%s/%s", namebuf, classbuf, vname);
+               RUNTIME_CHECK(n > 0 && (size_t)n < len);
                switch (ztype) {
                case CFG_ZONE_INVIEW:
-                       tresult = isc_symtab_lookup(inview, namebuf, 0, NULL);
+                       tresult = isc_symtab_lookup(inview, key, 0, NULL);
                        if (tresult != ISC_R_SUCCESS) {
                                cfg_obj_log(inviewobj, logctx, ISC_LOG_ERROR,
                                            "'in-view' zone '%s' "
@@ -3291,25 +3297,22 @@ check_zoneconf(const cfg_obj_t *zconfig, const cfg_obj_t *voptions,
                case CFG_ZONE_MIRROR:
                case CFG_ZONE_HINT:
                case CFG_ZONE_STUB:
-               case CFG_ZONE_STATICSTUB:
-                       tmp = isc_mem_strdup(mctx, namebuf);
+               case CFG_ZONE_STATICSTUB: {
+                       char *tmp = isc_mem_strdup(mctx, key);
+                       isc_symvalue_t symvalue;
+                       symvalue.as_cpointer = NULL;
+                       tresult = isc_symtab_define(inview, tmp, 1, symvalue,
+                                                   isc_symexists_replace);
+                       if (result == ISC_R_SUCCESS && tresult != ISC_R_SUCCESS)
                        {
-                               isc_symvalue_t symvalue;
-                               symvalue.as_cpointer = NULL;
-                               tresult = isc_symtab_define(
-                                       inview, tmp, 1, symvalue,
-                                       isc_symexists_replace);
-                               if (result == ISC_R_SUCCESS &&
-                                   tresult != ISC_R_SUCCESS)
-                               {
-                                       result = tresult;
-                               }
+                               result = tresult;
                        }
-                       break;
+               } break;
 
                default:
                        UNREACHABLE();
                }
+               isc_mem_put(mctx, key, len);
        }
 
        if (ztype == CFG_ZONE_INVIEW) {