From: Ondřej Surý Date: Thu, 14 Nov 2024 09:37:29 +0000 (+0100) Subject: Limit the additional processing for large RDATA sets X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9dc22c65e813c3e16781fb34a5199c6124938c1b;p=thirdparty%2Fbind9.git Limit the additional processing for large RDATA sets When answering queries, don't add data to the additional section if the answer has more than 13 names in the RDATA. This limits the number of lookups into the database(s) during a single client query, reducing query processing load. Also, don't append any additional data to type=ANY queries. The answer to ANY is already big enough. (cherry picked from commit a1982cf1bb95c818aa7b58988b5611dec80f2408) --- diff --git a/bin/tests/system/additional/tests.sh b/bin/tests/system/additional/tests.sh index 3701790678f..bf7b082f9af 100644 --- a/bin/tests/system/additional/tests.sh +++ b/bin/tests/system/additional/tests.sh @@ -278,7 +278,7 @@ n=$(expr $n + 1) echo_i "testing with 'minimal-any no;' ($n)" ret=0 $DIG $DIGOPTS -t ANY www.rt.example @10.53.0.1 >dig.out.$n || ret=1 -grep "ANSWER: 3, AUTHORITY: 2, ADDITIONAL: 2" dig.out.$n >/dev/null || ret=1 +grep "ANSWER: 3, AUTHORITY: 2, ADDITIONAL: 1" dig.out.$n >/dev/null || ret=1 if [ $ret -eq 1 ]; then echo_i "failed" status=$((status + 1)) diff --git a/lib/dns/include/dns/rdataset.h b/lib/dns/include/dns/rdataset.h index de3f638f895..b7f0f8f0551 100644 --- a/lib/dns/include/dns/rdataset.h +++ b/lib/dns/include/dns/rdataset.h @@ -55,6 +55,8 @@ #include #include +#define DNS_RDATASET_MAXADDITIONAL 13 + ISC_LANG_BEGINDECLS typedef enum { @@ -446,7 +448,8 @@ dns_rdataset_towirepartial(dns_rdataset_t *rdataset, isc_result_t dns_rdataset_additionaldata(dns_rdataset_t *rdataset, - dns_additionaldatafunc_t add, void *arg); + dns_additionaldatafunc_t add, void *arg, + size_t limit); /*%< * For each rdata in rdataset, call 'add' for each name and type in the * rdata which is subject to additional section processing. @@ -465,10 +468,15 @@ dns_rdataset_additionaldata(dns_rdataset_t *rdataset, *\li If a call to dns_rdata_additionaldata() is not successful, the * result returned will be the result of dns_rdataset_additionaldata(). * + *\li If 'limit' is non-zero and the number of the rdatasets is larger + * than 'limit', no additional data will be processed. + * * Returns: * *\li #ISC_R_SUCCESS * + *\li #DNS_R_TOOMANYRECORDS in case rdataset count is larger than 'limit' + * *\li Any error that dns_rdata_additionaldata() can return. */ diff --git a/lib/dns/rbtdb.c b/lib/dns/rbtdb.c index 5179f942fb5..24de5891371 100644 --- a/lib/dns/rbtdb.c +++ b/lib/dns/rbtdb.c @@ -10632,7 +10632,7 @@ no_glue: maybe_rehash_gluetable(rbtversion); idx = hash_32(hash, rbtversion->glue_table_bits); - (void)dns_rdataset_additionaldata(rdataset, glue_nsdname_cb, &ctx); + (void)dns_rdataset_additionaldata(rdataset, glue_nsdname_cb, &ctx, 0); cur = isc_mem_get(rbtdb->common.mctx, sizeof(*cur)); diff --git a/lib/dns/rdataset.c b/lib/dns/rdataset.c index 221d7f84a72..122b197612b 100644 --- a/lib/dns/rdataset.c +++ b/lib/dns/rdataset.c @@ -29,6 +29,7 @@ #include #include #include +#include static const char *trustnames[] = { "none", "pending-additional", @@ -578,7 +579,8 @@ dns_rdataset_towire(dns_rdataset_t *rdataset, const dns_name_t *owner_name, isc_result_t dns_rdataset_additionaldata(dns_rdataset_t *rdataset, - dns_additionaldatafunc_t add, void *arg) { + dns_additionaldatafunc_t add, void *arg, + size_t limit) { dns_rdata_t rdata = DNS_RDATA_INIT; isc_result_t result; @@ -590,6 +592,10 @@ dns_rdataset_additionaldata(dns_rdataset_t *rdataset, REQUIRE(DNS_RDATASET_VALID(rdataset)); REQUIRE((rdataset->attributes & DNS_RDATASETATTR_QUESTION) == 0); + if (limit != 0 && dns_rdataset_count(rdataset) > limit) { + return (DNS_R_TOOMANYRECORDS); + } + result = dns_rdataset_first(rdataset); if (result != ISC_R_SUCCESS) { return (result); diff --git a/lib/dns/resolver.c b/lib/dns/resolver.c index fe2c464329a..737f83cdbf5 100644 --- a/lib/dns/resolver.c +++ b/lib/dns/resolver.c @@ -9025,8 +9025,8 @@ rctx_answer_any(respctx_t *rctx) { rdataset->attributes |= DNS_RDATASETATTR_CACHE; rdataset->trust = rctx->trust; - (void)dns_rdataset_additionaldata(rdataset, check_related, - rctx); + (void)dns_rdataset_additionaldata(rdataset, check_related, rctx, + 0); } return (ISC_R_SUCCESS); @@ -9073,7 +9073,8 @@ rctx_answer_match(respctx_t *rctx) { rctx->ardataset->attributes |= DNS_RDATASETATTR_ANSWER; rctx->ardataset->attributes |= DNS_RDATASETATTR_CACHE; rctx->ardataset->trust = rctx->trust; - (void)dns_rdataset_additionaldata(rctx->ardataset, check_related, rctx); + (void)dns_rdataset_additionaldata(rctx->ardataset, check_related, rctx, + 0); for (sigrdataset = ISC_LIST_HEAD(rctx->aname->list); sigrdataset != NULL; @@ -9279,7 +9280,8 @@ rctx_authority_positive(respctx_t *rctx) { * to this rdataset. */ (void)dns_rdataset_additionaldata( - rdataset, check_related, rctx); + rdataset, check_related, rctx, + 0); done = true; } } @@ -9786,8 +9788,11 @@ rctx_referral(respctx_t *rctx) { */ INSIST(rctx->ns_rdataset != NULL); FCTX_ATTR_SET(fctx, FCTX_ATTR_GLUING); + /* + * Mark the glue records in the additional section to be cached. + */ (void)dns_rdataset_additionaldata(rctx->ns_rdataset, check_related, - rctx); + rctx, 0); #if CHECK_FOR_GLUE_IN_ANSWER /* * Look in the answer section for "glue" that is incorrectly @@ -9800,7 +9805,7 @@ rctx_referral(respctx_t *rctx) { (fctx->type == dns_rdatatype_aaaa || fctx->type == dns_rdatatype_a)) { (void)dns_rdataset_additionaldata(rctx->ns_rdataset, - check_answer, fctx); + check_answer, fctx, 0); } #endif /* if CHECK_FOR_GLUE_IN_ANSWER */ FCTX_ATTR_CLR(fctx, FCTX_ATTR_GLUING); @@ -9910,7 +9915,7 @@ again: if (CHASE(rdataset)) { rdataset->attributes &= ~DNS_RDATASETATTR_CHASE; (void)dns_rdataset_additionaldata( - rdataset, check_related, rctx); + rdataset, check_related, rctx, 0); rescan = true; } } diff --git a/lib/ns/query.c b/lib/ns/query.c index b729d119215..7d80bd9cc9a 100644 --- a/lib/ns/query.c +++ b/lib/ns/query.c @@ -2037,7 +2037,8 @@ addname: if (trdataset != NULL && dns_rdatatype_followadditional(type)) { eresult = dns_rdataset_additionaldata( - trdataset, query_additional_cb, qctx); + trdataset, query_additional_cb, qctx, + DNS_RDATASET_MAXADDITIONAL); } cleanup: @@ -2128,7 +2129,8 @@ regular: * Add other additional data if needed. * We don't care if dns_rdataset_additionaldata() fails. */ - (void)dns_rdataset_additionaldata(rdataset, query_additional_cb, qctx); + (void)dns_rdataset_additionaldata(rdataset, query_additional_cb, qctx, + DNS_RDATASET_MAXADDITIONAL); CTRACE(ISC_LOG_DEBUG(3), "query_additional: done"); } @@ -2154,7 +2156,8 @@ query_addrrset(query_ctx_t *qctx, dns_name_t **namep, * To the current response for 'client', add the answer RRset * '*rdatasetp' and an optional signature set '*sigrdatasetp', with * owner name '*namep', to section 'section', unless they are - * already there. Also add any pertinent additional data. + * already there. Also add any pertinent additional data, unless + * the query was for type ANY. * * If 'dbuf' is not NULL, then '*namep' is the name whose data is * stored in 'dbuf'. In this case, query_addrrset() guarantees that @@ -2209,7 +2212,9 @@ query_addrrset(query_ctx_t *qctx, dns_name_t **namep, */ query_addtoname(mname, rdataset); query_setorder(qctx, mname, rdataset); - query_additional(qctx, rdataset); + if (qctx->qtype != dns_rdatatype_any) { + query_additional(qctx, rdataset); + } /* * Note: we only add SIGs if we've added the type they cover, so