diff options
Diffstat (limited to 'util/data/msgencode.c')
| -rw-r--r-- | util/data/msgencode.c | 73 |
1 files changed, 63 insertions, 10 deletions
diff --git a/util/data/msgencode.c b/util/data/msgencode.c index 034bb24bd6e4..5d3a24762178 100644 --- a/util/data/msgencode.c +++ b/util/data/msgencode.c @@ -48,6 +48,7 @@ #include "util/regional.h" #include "util/net_help.h" #include "sldns/sbuffer.h" +#include "services/localzone.h" /** return code that means the function ran out of memory. negative so it does * not conflict with DNS rcodes. */ @@ -534,7 +535,11 @@ insert_section(struct reply_info* rep, size_t num_rrsets, uint16_t* num_rrs, { int r; size_t i, setstart; - *num_rrs = 0; + /* we now allow this function to be called multiple times for the + * same section, incrementally updating num_rrs. The caller is + * responsible for initializing it (which is the case in the current + * implementation). */ + if(s != LDNS_SECTION_ADDITIONAL) { if(s == LDNS_SECTION_ANSWER && qtype == LDNS_RR_TYPE_ANY) dnssec = 1; /* include all types in ANY answer */ @@ -581,17 +586,20 @@ static int insert_query(struct query_info* qinfo, struct compress_tree_node** tree, sldns_buffer* buffer, struct regional* region) { + uint8_t* qname = qinfo->local_alias ? + qinfo->local_alias->rrset->rk.dname : qinfo->qname; + size_t qname_len = qinfo->local_alias ? + qinfo->local_alias->rrset->rk.dname_len : qinfo->qname_len; if(sldns_buffer_remaining(buffer) < qinfo->qname_len+sizeof(uint16_t)*2) return RETVAL_TRUNC; /* buffer too small */ /* the query is the first name inserted into the tree */ - if(!compress_tree_store(qinfo->qname, - dname_count_labels(qinfo->qname), + if(!compress_tree_store(qname, dname_count_labels(qname), sldns_buffer_position(buffer), region, NULL, tree)) return RETVAL_OUTMEM; - if(sldns_buffer_current(buffer) == qinfo->qname) - sldns_buffer_skip(buffer, (ssize_t)qinfo->qname_len); - else sldns_buffer_write(buffer, qinfo->qname, qinfo->qname_len); + if(sldns_buffer_current(buffer) == qname) + sldns_buffer_skip(buffer, (ssize_t)qname_len); + else sldns_buffer_write(buffer, qname, qname_len); sldns_buffer_write_u16(buffer, qinfo->qtype); sldns_buffer_write_u16(buffer, qinfo->qclass); return RETVAL_OK; @@ -662,6 +670,33 @@ reply_info_encode(struct query_info* qinfo, struct reply_info* rep, * for different roundrobins for sequential id client senders. */ rr_offset = RRSET_ROUNDROBIN?ntohs(id):0; + /* "prepend" any local alias records in the answer section if this + * response is supposed to be authoritative. Currently it should + * be a single CNAME record (sanity-checked in worker_handle_request()) + * but it can be extended if and when we support more variations of + * aliases. */ + if(qinfo->local_alias && (flags & BIT_AA)) { + struct reply_info arep; + time_t timezero = 0; /* to use the 'authoritative' TTL */ + memset(&arep, 0, sizeof(arep)); + arep.flags = rep->flags; + arep.an_numrrsets = 1; + arep.rrset_count = 1; + arep.rrsets = &qinfo->local_alias->rrset; + if((r=insert_section(&arep, 1, &ancount, buffer, 0, + timezero, region, &tree, LDNS_SECTION_ANSWER, + qinfo->qtype, dnssec, rr_offset)) != RETVAL_OK) { + if(r == RETVAL_TRUNC) { + /* create truncated message */ + sldns_buffer_write_u16_at(buffer, 6, ancount); + LDNS_TC_SET(sldns_buffer_begin(buffer)); + sldns_buffer_flip(buffer); + return 1; + } + return 0; + } + } + /* insert answer section */ if((r=insert_section(rep, rep->an_numrrsets, &ancount, buffer, 0, timenow, region, &tree, LDNS_SECTION_ANSWER, qinfo->qtype, @@ -782,6 +817,15 @@ reply_info_answer_encode(struct query_info* qinf, struct reply_info* rep, } if(secure && (dnssec || (qflags&BIT_AD))) flags |= BIT_AD; + /* restore AA bit if we have a local alias and the response can be + * authoritative. Also clear AD bit if set as the local data is the + * primary answer. */ + if(qinf->local_alias && + (FLAGS_GET_RCODE(rep->flags) == LDNS_RCODE_NOERROR || + FLAGS_GET_RCODE(rep->flags) == LDNS_RCODE_NXDOMAIN)) { + flags |= BIT_AA; + flags &= ~BIT_AD; + } log_assert(flags & BIT_QR); /* QR bit must be on in our replies */ if(udpsize < LDNS_HEADER_SIZE) return 0; @@ -807,13 +851,17 @@ void qinfo_query_encode(sldns_buffer* pkt, struct query_info* qinfo) { uint16_t flags = 0; /* QUERY, NOERROR */ + const uint8_t* qname = qinfo->local_alias ? + qinfo->local_alias->rrset->rk.dname : qinfo->qname; + size_t qname_len = qinfo->local_alias ? + qinfo->local_alias->rrset->rk.dname_len : qinfo->qname_len; sldns_buffer_clear(pkt); log_assert(sldns_buffer_remaining(pkt) >= 12+255+4/*max query*/); sldns_buffer_skip(pkt, 2); /* id done later */ sldns_buffer_write_u16(pkt, flags); sldns_buffer_write_u16(pkt, 1); /* query count */ sldns_buffer_write(pkt, "\000\000\000\000\000\000", 6); /* counts */ - sldns_buffer_write(pkt, qinfo->qname, qinfo->qname_len); + sldns_buffer_write(pkt, qname, qname_len); sldns_buffer_write_u16(pkt, qinfo->qtype); sldns_buffer_write_u16(pkt, qinfo->qclass); sldns_buffer_flip(pkt); @@ -838,9 +886,14 @@ error_encode(sldns_buffer* buf, int r, struct query_info* qinfo, sldns_buffer_write(buf, &flags, sizeof(uint16_t)); sldns_buffer_write(buf, &flags, sizeof(uint16_t)); if(qinfo) { - if(sldns_buffer_current(buf) == qinfo->qname) - sldns_buffer_skip(buf, (ssize_t)qinfo->qname_len); - else sldns_buffer_write(buf, qinfo->qname, qinfo->qname_len); + const uint8_t* qname = qinfo->local_alias ? + qinfo->local_alias->rrset->rk.dname : qinfo->qname; + size_t qname_len = qinfo->local_alias ? + qinfo->local_alias->rrset->rk.dname_len : + qinfo->qname_len; + if(sldns_buffer_current(buf) == qname) + sldns_buffer_skip(buf, (ssize_t)qname_len); + else sldns_buffer_write(buf, qname, qname_len); sldns_buffer_write_u16(buf, qinfo->qtype); sldns_buffer_write_u16(buf, qinfo->qclass); } |