int parse_packet(sldns_buffer* pkt, struct msg_parse* msg, struct regional* region) { int ret; if(sldns_buffer_remaining(pkt) < LDNS_HEADER_SIZE) return LDNS_RCODE_FORMERR; /* read the header */ sldns_buffer_read(pkt, &msg->id, sizeof(uint16_t)); msg->flags = sldns_buffer_read_u16(pkt); msg->qdcount = sldns_buffer_read_u16(pkt); msg->ancount = sldns_buffer_read_u16(pkt); msg->nscount = sldns_buffer_read_u16(pkt); msg->arcount = sldns_buffer_read_u16(pkt); if(msg->qdcount > 1) return LDNS_RCODE_FORMERR; if((ret = parse_query_section(pkt, msg)) != 0) return ret; if((ret = parse_section(pkt, msg, region, LDNS_SECTION_ANSWER, msg->ancount, &msg->an_rrsets)) != 0) return ret; if((ret = parse_section(pkt, msg, region, LDNS_SECTION_AUTHORITY, msg->nscount, &msg->ns_rrsets)) != 0) return ret; if(sldns_buffer_remaining(pkt) == 0 && msg->arcount == 1) { /* BIND accepts leniently that an EDNS record is missing. * so, we do too. */ } else if((ret = parse_section(pkt, msg, region, LDNS_SECTION_ADDITIONAL, msg->arcount, &msg->ar_rrsets)) != 0) return ret; /* if(sldns_buffer_remaining(pkt) > 0) { */ /* there is spurious data at end of packet. ignore */ /* } */ msg->rrset_count = msg->an_rrsets + msg->ns_rrsets + msg->ar_rrsets; return 0; }
/** compress a domain name */ static int write_compressed_dname(sldns_buffer* pkt, uint8_t* dname, int labs, struct compress_tree_node* p) { /* compress it */ int labcopy = labs - p->labs; uint8_t lablen; uint16_t ptr; if(labs == 1) { /* write root label */ if(sldns_buffer_remaining(pkt) < 1) return 0; sldns_buffer_write_u8(pkt, 0); return 1; } /* copy the first couple of labels */ while(labcopy--) { lablen = *dname++; if(sldns_buffer_remaining(pkt) < (size_t)lablen+1) return 0; sldns_buffer_write_u8(pkt, lablen); sldns_buffer_write(pkt, dname, lablen); dname += lablen; } /* insert compression ptr */ if(sldns_buffer_remaining(pkt) < 2) return 0; ptr = PTR_CREATE(p->offset); sldns_buffer_write_u16(pkt, ptr); return 1; }
/** compress domain names in rdata, return RETVAL_* */ static int compress_rdata(sldns_buffer* pkt, uint8_t* rdata, size_t todolen, struct regional* region, struct compress_tree_node** tree, const sldns_rr_descriptor* desc) { int labs, r, rdf = 0; size_t dname_len, len, pos = sldns_buffer_position(pkt); uint8_t count = desc->_dname_count; sldns_buffer_skip(pkt, 2); /* rdata len fill in later */ /* space for rdatalen checked for already */ rdata += 2; todolen -= 2; while(todolen > 0 && count) { switch(desc->_wireformat[rdf]) { case LDNS_RDF_TYPE_DNAME: labs = dname_count_size_labels(rdata, &dname_len); if((r=compress_any_dname(rdata, pkt, labs, region, tree)) != RETVAL_OK) return r; rdata += dname_len; todolen -= dname_len; count--; len = 0; break; case LDNS_RDF_TYPE_STR: len = *rdata + 1; break; default: len = get_rdf_size(desc->_wireformat[rdf]); } if(len) { /* copy over */ if(sldns_buffer_remaining(pkt) < len) return RETVAL_TRUNC; sldns_buffer_write(pkt, rdata, len); todolen -= len; rdata += len; } rdf++; } /* copy remainder */ if(todolen > 0) { if(sldns_buffer_remaining(pkt) < todolen) return RETVAL_TRUNC; sldns_buffer_write(pkt, rdata, todolen); } /* set rdata len */ sldns_buffer_write_u16_at(pkt, pos, sldns_buffer_position(pkt)-pos-2); return RETVAL_OK; }
/** skip rr ttl and rdata */ static int skip_ttl_rdata(sldns_buffer* pkt) { uint16_t rdatalen; if(sldns_buffer_remaining(pkt) < 6) /* ttl + rdatalen */ return 0; sldns_buffer_skip(pkt, 4); /* ttl */ rdatalen = sldns_buffer_read_u16(pkt); if(sldns_buffer_remaining(pkt) < rdatalen) return 0; sldns_buffer_skip(pkt, (ssize_t)rdatalen); return 1; }
size_t pkt_dname_len(sldns_buffer* pkt) { size_t len = 0; int ptrcount = 0; uint8_t labellen; size_t endpos = 0; /* read dname and determine length */ /* check compression pointers, loops, out of bounds */ while(1) { /* read next label */ if(sldns_buffer_remaining(pkt) < 1) return 0; labellen = sldns_buffer_read_u8(pkt); if(LABEL_IS_PTR(labellen)) { /* compression ptr */ uint16_t ptr; if(sldns_buffer_remaining(pkt) < 1) return 0; ptr = PTR_OFFSET(labellen, sldns_buffer_read_u8(pkt)); if(ptrcount++ > MAX_COMPRESS_PTRS) return 0; /* loop! */ if(sldns_buffer_limit(pkt) <= ptr) return 0; /* out of bounds! */ if(!endpos) endpos = sldns_buffer_position(pkt); sldns_buffer_set_position(pkt, ptr); } else { /* label contents */ if(labellen > 0x3f) return 0; /* label too long */ len += 1 + labellen; if(len > LDNS_MAX_DOMAINLEN) return 0; if(labellen == 0) { /* end of dname */ break; } if(sldns_buffer_remaining(pkt) < labellen) return 0; sldns_buffer_skip(pkt, (ssize_t)labellen); } } if(endpos) sldns_buffer_set_position(pkt, endpos); return len; }
/** analyse pkt */ static void analyze(sldns_buffer* pkt) { uint16_t i, f, qd, an, ns, ar; int rrnum = 0; printf("packet length %d\n", (int)sldns_buffer_limit(pkt)); if(sldns_buffer_limit(pkt) < 12) return; i = sldns_buffer_read_u16(pkt); printf("id (hostorder): %d (0x%x)\n", (int)i, (unsigned)i); f = sldns_buffer_read_u16(pkt); printf("flags: 0x%x\n", (unsigned)f); qd = sldns_buffer_read_u16(pkt); printf("qdcount: %d\n", (int)qd); an = sldns_buffer_read_u16(pkt); printf("ancount: %d\n", (int)an); ns = sldns_buffer_read_u16(pkt); printf("nscount: %d\n", (int)ns); ar = sldns_buffer_read_u16(pkt); printf("arcount: %d\n", (int)ar); printf(";-- query section\n"); while(sldns_buffer_remaining(pkt) > 0) { if(rrnum == (int)qd) printf(";-- answer section\n"); if(rrnum == (int)qd+(int)an) printf(";-- authority section\n"); if(rrnum == (int)qd+(int)an+(int)ns) printf(";-- additional section\n"); printf("rr %d ", rrnum); analyze_rr(pkt, rrnum < (int)qd); rrnum++; } }
int parse_edns_from_pkt(sldns_buffer* pkt, struct edns_data* edns) { log_assert(LDNS_QDCOUNT(sldns_buffer_begin(pkt)) == 1); log_assert(LDNS_ANCOUNT(sldns_buffer_begin(pkt)) == 0); log_assert(LDNS_NSCOUNT(sldns_buffer_begin(pkt)) == 0); /* check edns section is present */ if(LDNS_ARCOUNT(sldns_buffer_begin(pkt)) > 1) { return LDNS_RCODE_FORMERR; } if(LDNS_ARCOUNT(sldns_buffer_begin(pkt)) == 0) { memset(edns, 0, sizeof(*edns)); edns->udp_size = 512; return 0; } /* domain name must be the root of length 1. */ if(pkt_dname_len(pkt) != 1) return LDNS_RCODE_FORMERR; if(sldns_buffer_remaining(pkt) < 10) /* type, class, ttl, rdatalen */ return LDNS_RCODE_FORMERR; if(sldns_buffer_read_u16(pkt) != LDNS_RR_TYPE_OPT) return LDNS_RCODE_FORMERR; edns->edns_present = 1; edns->udp_size = sldns_buffer_read_u16(pkt); /* class is udp size */ edns->ext_rcode = sldns_buffer_read_u8(pkt); /* ttl used for bits */ edns->edns_version = sldns_buffer_read_u8(pkt); edns->bits = sldns_buffer_read_u16(pkt); /* ignore rdata and rrsigs */ return 0; }
/** compress owner name of RR, return RETVAL_OUTMEM RETVAL_TRUNC */ static int compress_owner(struct ub_packed_rrset_key* key, sldns_buffer* pkt, struct regional* region, struct compress_tree_node** tree, size_t owner_pos, uint16_t* owner_ptr, int owner_labs) { struct compress_tree_node* p; struct compress_tree_node** insertpt = NULL; if(!*owner_ptr) { /* compress first time dname */ if((p = compress_tree_lookup(tree, key->rk.dname, owner_labs, &insertpt))) { if(p->labs == owner_labs) /* avoid ptr chains, since some software is * not capable of decoding ptr after a ptr. */ *owner_ptr = htons(PTR_CREATE(p->offset)); if(!write_compressed_dname(pkt, key->rk.dname, owner_labs, p)) return RETVAL_TRUNC; /* check if typeclass+4 ttl + rdatalen is available */ if(sldns_buffer_remaining(pkt) < 4+4+2) return RETVAL_TRUNC; } else { /* no compress */ if(sldns_buffer_remaining(pkt) < key->rk.dname_len+4+4+2) return RETVAL_TRUNC; sldns_buffer_write(pkt, key->rk.dname, key->rk.dname_len); if(owner_pos <= PTR_MAX_OFFSET) *owner_ptr = htons(PTR_CREATE(owner_pos)); } if(!compress_tree_store(key->rk.dname, owner_labs, owner_pos, region, p, insertpt)) return RETVAL_OUTMEM; } else { /* always compress 2nd-further RRs in RRset */ if(owner_labs == 1) { if(sldns_buffer_remaining(pkt) < 1+4+4+2) return RETVAL_TRUNC; sldns_buffer_write_u8(pkt, 0); } else { if(sldns_buffer_remaining(pkt) < 2+4+4+2) return RETVAL_TRUNC; sldns_buffer_write(pkt, owner_ptr, 2); } } return RETVAL_OK; }
/** calculate the size of one rr */ static int calc_size(sldns_buffer* pkt, uint16_t type, struct rr_parse* rr) { const sldns_rr_descriptor* desc; uint16_t pkt_len; /* length of rr inside the packet */ rr->size = sizeof(uint16_t); /* the rdatalen */ sldns_buffer_skip(pkt, 4); /* skip ttl */ pkt_len = sldns_buffer_read_u16(pkt); if(sldns_buffer_remaining(pkt) < pkt_len) return 0; desc = sldns_rr_descript(type); if(pkt_len > 0 && desc && desc->_dname_count > 0) { int count = (int)desc->_dname_count; int rdf = 0; size_t len; size_t oldpos; /* skip first part. */ while(pkt_len > 0 && count) { switch(desc->_wireformat[rdf]) { case LDNS_RDF_TYPE_DNAME: /* decompress every domain name */ oldpos = sldns_buffer_position(pkt); if((len = pkt_dname_len(pkt)) == 0) return 0; /* malformed dname */ if(sldns_buffer_position(pkt)-oldpos > pkt_len) return 0; /* dname exceeds rdata */ pkt_len -= sldns_buffer_position(pkt)-oldpos; rr->size += len; count--; len = 0; break; case LDNS_RDF_TYPE_STR: if(pkt_len < 1) { /* NOTREACHED, due to 'while(>0)' */ return 0; /* len byte exceeds rdata */ } len = sldns_buffer_current(pkt)[0] + 1; break; default: len = get_rdf_size(desc->_wireformat[rdf]); } if(len) { if(pkt_len < len) return 0; /* exceeds rdata */ pkt_len -= len; sldns_buffer_skip(pkt, (ssize_t)len); rr->size += len; } rdf++; } } /* remaining rdata */ rr->size += pkt_len; sldns_buffer_skip(pkt, (ssize_t)pkt_len); return 1; }
/** See if next rrset is nsec at zone apex */ static int nsec_at_apex(sldns_buffer* pkt) { /* we are at ttl position in packet. */ size_t pos = sldns_buffer_position(pkt); uint16_t rdatalen; if(sldns_buffer_remaining(pkt) < 7) /* ttl+len+root */ return 0; /* eek! */ sldns_buffer_skip(pkt, 4); /* ttl */; rdatalen = sldns_buffer_read_u16(pkt); if(sldns_buffer_remaining(pkt) < rdatalen) { sldns_buffer_set_position(pkt, pos); return 0; /* parse error happens later */ } /* must validate the nsec next domain name format */ if(pkt_dname_len(pkt) == 0) { sldns_buffer_set_position(pkt, pos); return 0; /* parse error */ } /* see if SOA bit is set. */ if(sldns_buffer_position(pkt) < pos+4+rdatalen) { /* nsec type bitmap contains items */ uint8_t win, blen, bits; /* need: windownum, bitmap len, firstbyte */ if(sldns_buffer_position(pkt)+3 > pos+4+rdatalen) { sldns_buffer_set_position(pkt, pos); return 0; /* malformed nsec */ } win = sldns_buffer_read_u8(pkt); blen = sldns_buffer_read_u8(pkt); bits = sldns_buffer_read_u8(pkt); /* 0window always first window. bitlen >=1 or parse error really. bit 0x2 is SOA. */ if(win == 0 && blen >= 1 && (bits & 0x02)) { sldns_buffer_set_position(pkt, pos); return 1; } } sldns_buffer_set_position(pkt, pos); return 0; }
int dname_buffer_write(sldns_buffer* pkt, uint8_t* dname) { uint8_t lablen; if(sldns_buffer_remaining(pkt) < 1) return 0; lablen = *dname++; sldns_buffer_write_u8(pkt, lablen); while(lablen) { if(sldns_buffer_remaining(pkt) < (size_t)lablen+1) return 0; sldns_buffer_write(pkt, dname, lablen); dname += lablen; lablen = *dname++; sldns_buffer_write_u8(pkt, lablen); } return 1; }
/** * Parse query section. * @param pkt: packet, position at call must be at start of query section. * at end position is after query section. * @param msg: store results here. * @return: 0 if OK, or rcode on error. */ static int parse_query_section(sldns_buffer* pkt, struct msg_parse* msg) { if(msg->qdcount == 0) return 0; if(msg->qdcount > 1) return LDNS_RCODE_FORMERR; log_assert(msg->qdcount == 1); if(sldns_buffer_remaining(pkt) <= 0) return LDNS_RCODE_FORMERR; msg->qname = sldns_buffer_current(pkt); if((msg->qname_len = pkt_dname_len(pkt)) == 0) return LDNS_RCODE_FORMERR; if(sldns_buffer_remaining(pkt) < sizeof(uint16_t)*2) return LDNS_RCODE_FORMERR; msg->qtype = sldns_buffer_read_u16(pkt); msg->qclass = sldns_buffer_read_u16(pkt); return 0; }
/** * Create canonical form of rrset in the scratch buffer. * @param region: temporary region. * @param buf: the buffer to use. * @param k: the rrset to insert. * @param sig: RRSIG rdata to include. * @param siglen: RRSIG rdata len excluding signature field, but inclusive * signer name length. * @param sortree: if NULL is passed a new sorted rrset tree is built. * Otherwise it is reused. * @return false on alloc error. */ static int rrset_canonical(struct regional* region, sldns_buffer* buf, struct ub_packed_rrset_key* k, uint8_t* sig, size_t siglen, struct rbtree_t** sortree) { struct packed_rrset_data* d = (struct packed_rrset_data*)k->entry.data; uint8_t* can_owner = NULL; size_t can_owner_len = 0; struct canon_rr* walk; struct canon_rr* rrs; if(!*sortree) { *sortree = (struct rbtree_t*)regional_alloc(region, sizeof(rbtree_t)); if(!*sortree) return 0; if(d->count > RR_COUNT_MAX) return 0; /* integer overflow protection */ rrs = regional_alloc(region, sizeof(struct canon_rr)*d->count); if(!rrs) { *sortree = NULL; return 0; } rbtree_init(*sortree, &canonical_tree_compare); canonical_sort(k, d, *sortree, rrs); } sldns_buffer_clear(buf); sldns_buffer_write(buf, sig, siglen); /* canonicalize signer name */ query_dname_tolower(sldns_buffer_begin(buf)+18); RBTREE_FOR(walk, struct canon_rr*, (*sortree)) { /* see if there is enough space left in the buffer */ if(sldns_buffer_remaining(buf) < can_owner_len + 2 + 2 + 4 + d->rr_len[walk->rr_idx]) { log_err("verify: failed to canonicalize, " "rrset too big"); return 0; } /* determine canonical owner name */ if(can_owner) sldns_buffer_write(buf, can_owner, can_owner_len); else insert_can_owner(buf, k, sig, &can_owner, &can_owner_len); sldns_buffer_write(buf, &k->rk.type, 2); sldns_buffer_write(buf, &k->rk.rrset_class, 2); sldns_buffer_write(buf, sig+4, 4); sldns_buffer_write(buf, d->rr_data[walk->rr_idx], d->rr_len[walk->rr_idx]); canonicalize_rdata(buf, k, d->rr_len[walk->rr_idx]); } sldns_buffer_flip(buf); return 1; }
/* determine length of a dname in buffer, no compression pointers allowed */ size_t query_dname_len(sldns_buffer* query) { size_t len = 0; size_t labellen; while(1) { if(sldns_buffer_remaining(query) < 1) return 0; /* parse error, need label len */ labellen = sldns_buffer_read_u8(query); if(labellen&0xc0) return 0; /* no compression allowed in queries */ len += labellen + 1; if(len > LDNS_MAX_DOMAINLEN) return 0; /* too long */ if(labellen == 0) return len; if(sldns_buffer_remaining(query) < labellen) return 0; /* parse error, need content */ sldns_buffer_skip(query, (ssize_t)labellen); } }
/** see if RRSIG is a duplicate of another */ static int sig_is_double(sldns_buffer* pkt, struct rrset_parse* rrset, uint8_t* ttldata) { uint16_t rlen, siglen; size_t pos = sldns_buffer_position(pkt); struct rr_parse* sig; if(sldns_buffer_remaining(pkt) < 6) return 0; sldns_buffer_skip(pkt, 4); /* ttl */ rlen = sldns_buffer_read_u16(pkt); if(sldns_buffer_remaining(pkt) < rlen) { sldns_buffer_set_position(pkt, pos); return 0; } sldns_buffer_set_position(pkt, pos); sig = rrset->rrsig_first; while(sig) { /* check if rdatalen is same */ memmove(&siglen, sig->ttl_data+4, sizeof(siglen)); siglen = ntohs(siglen); /* checks if data in packet is exactly the same, this means * also dname in rdata is the same, but rrsig is not allowed * to have compressed dnames anyway. If it is compressed anyway * it will lead to duplicate rrs for qtype=RRSIG. (or ANY). * * Cannot use sig->size because size of the other one is not * calculated yet. */ if(siglen == rlen) { if(siglen>0 && memcmp(sig->ttl_data+6, ttldata+6, siglen) == 0) { /* same! */ return 1; } } sig = sig->next; } return 0; }
int sldns_buffer_printf(sldns_buffer *buffer, const char *format, ...) { va_list args; int written = 0; size_t remaining; if (sldns_buffer_status_ok(buffer)) { sldns_buffer_invariant(buffer); assert(buffer->_limit == buffer->_capacity); remaining = sldns_buffer_remaining(buffer); va_start(args, format); written = vsnprintf((char *) sldns_buffer_current(buffer), remaining, format, args); va_end(args); if (written == -1) { buffer->_status_err = 1; return -1; } else if ((size_t) written >= remaining) { if (!sldns_buffer_reserve(buffer, (size_t) written + 1)) { buffer->_status_err = 1; return -1; } va_start(args, format); written = vsnprintf((char *) sldns_buffer_current(buffer), sldns_buffer_remaining(buffer), format, args); va_end(args); if (written == -1) { buffer->_status_err = 1; return -1; } } buffer->_position += written; } return written; }
void qinfo_query_encode(sldns_buffer* pkt, struct query_info* qinfo) { uint16_t flags = 0; /* QUERY, NOERROR */ 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_u16(pkt, qinfo->qtype); sldns_buffer_write_u16(pkt, qinfo->qclass); sldns_buffer_flip(pkt); }
/** return type networkformat that rrsig in packet covers */ static int pkt_rrsig_covered(sldns_buffer* pkt, uint8_t* here, uint16_t* type) { size_t pos = sldns_buffer_position(pkt); sldns_buffer_set_position(pkt, (size_t)(here-sldns_buffer_begin(pkt))); /* ttl + len + size of small rrsig(rootlabel, no signature) */ if(sldns_buffer_remaining(pkt) < 4+2+19) return 0; sldns_buffer_skip(pkt, 4); /* ttl */ if(sldns_buffer_read_u16(pkt) < 19) /* too short */ { sldns_buffer_set_position(pkt, pos); return 0; } *type = sldns_buffer_read_u16(pkt); sldns_buffer_set_position(pkt, pos); return 1; }
/** add result to the bg worker result queue */ static void add_bg_result(struct libworker* w, struct ctx_query* q, sldns_buffer* pkt, int err, char* reason) { uint8_t* msg = NULL; uint32_t len = 0; if(w->want_quit) { context_query_delete(q); return; } /* serialize and delete unneeded q */ if(w->is_bg_thread) { lock_basic_lock(&w->ctx->cfglock); if(reason) q->res->why_bogus = strdup(reason); if(pkt) { q->msg_len = sldns_buffer_remaining(pkt); q->msg = memdup(sldns_buffer_begin(pkt), q->msg_len); if(!q->msg) msg = context_serialize_answer(q, UB_NOMEM, NULL, &len); else msg = context_serialize_answer(q, err, NULL, &len); } else msg = context_serialize_answer(q, err, NULL, &len); lock_basic_unlock(&w->ctx->cfglock); } else { if(reason) q->res->why_bogus = strdup(reason); msg = context_serialize_answer(q, err, pkt, &len); (void)rbtree_delete(&w->ctx->queries, q->node.key); w->ctx->num_async--; context_query_delete(q); } if(!msg) { log_err("out of memory for async answer"); return; } if(!tube_queue_item(w->ctx->rr_pipe, msg, len)) { log_err("out of memory for async answer"); return; } }
/** store query section in wireformat buffer, return RETVAL */ static int insert_query(struct query_info* qinfo, struct compress_tree_node** tree, sldns_buffer* buffer, struct regional* region) { 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), 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); sldns_buffer_write_u16(buffer, qinfo->qtype); sldns_buffer_write_u16(buffer, qinfo->qclass); return RETVAL_OK; }
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, qname, qname_len); sldns_buffer_write_u16(pkt, qinfo->qtype); sldns_buffer_write_u16(pkt, qinfo->qclass); sldns_buffer_flip(pkt); }
int query_info_parse(struct query_info* m, sldns_buffer* query) { uint8_t* q = sldns_buffer_begin(query); /* minimum size: header + \0 + qtype + qclass */ if(sldns_buffer_limit(query) < LDNS_HEADER_SIZE + 5) return 0; if(LDNS_OPCODE_WIRE(q) != LDNS_PACKET_QUERY || LDNS_QDCOUNT(q) != 1 || sldns_buffer_position(query) != 0) return 0; sldns_buffer_skip(query, LDNS_HEADER_SIZE); m->qname = sldns_buffer_current(query); if((m->qname_len = query_dname_len(query)) == 0) return 0; /* parse error */ if(sldns_buffer_remaining(query) < 4) return 0; /* need qtype, qclass */ m->qtype = sldns_buffer_read_u16(query); m->qclass = sldns_buffer_read_u16(query); return 1; }
/** * Parse packet RR section, for answer, authority and additional sections. * @param pkt: packet, position at call must be at start of section. * at end position is after section. * @param msg: store results here. * @param region: how to alloc results. * @param section: section enum. * @param num_rrs: how many rrs are in the section. * @param num_rrsets: returns number of rrsets in the section. * @return: 0 if OK, or rcode on error. */ static int parse_section(sldns_buffer* pkt, struct msg_parse* msg, struct regional* region, sldns_pkt_section section, uint16_t num_rrs, size_t* num_rrsets) { uint16_t i; uint8_t* dname, *prev_dname_f = NULL, *prev_dname_l = NULL; size_t dnamelen, prev_dnamelen = 0; uint16_t type, prev_type = 0; uint16_t dclass, prev_dclass = 0; uint32_t rrset_flags = 0; hashvalue_t hash = 0; struct rrset_parse* rrset = NULL; int r; if(num_rrs == 0) return 0; if(sldns_buffer_remaining(pkt) <= 0) return LDNS_RCODE_FORMERR; for(i=0; i<num_rrs; i++) { /* parse this RR. */ dname = sldns_buffer_current(pkt); if((dnamelen = pkt_dname_len(pkt)) == 0) return LDNS_RCODE_FORMERR; if(sldns_buffer_remaining(pkt) < 10) /* type, class, ttl, len */ return LDNS_RCODE_FORMERR; type = sldns_buffer_read_u16(pkt); sldns_buffer_read(pkt, &dclass, sizeof(dclass)); if(0) { /* debug show what is being parsed. */ if(type == LDNS_RR_TYPE_RRSIG) { uint16_t t; if(pkt_rrsig_covered(pkt, sldns_buffer_current(pkt), &t)) fprintf(stderr, "parse of %s(%d) [%s(%d)]", sldns_rr_descript(type)? sldns_rr_descript(type)->_name: "??", (int)type, sldns_rr_descript(t)? sldns_rr_descript(t)->_name: "??", (int)t); } else fprintf(stderr, "parse of %s(%d)", sldns_rr_descript(type)? sldns_rr_descript(type)->_name: "??", (int)type); fprintf(stderr, " %s(%d) ", sldns_lookup_by_id(sldns_rr_classes, (int)ntohs(dclass))?sldns_lookup_by_id( sldns_rr_classes, (int)ntohs(dclass))->name: "??", (int)ntohs(dclass)); dname_print(stderr, pkt, dname); fprintf(stderr, "\n"); } /* see if it is part of an existing RR set */ if(!find_rrset(msg, pkt, dname, dnamelen, type, dclass, &hash, &rrset_flags, &prev_dname_f, &prev_dname_l, &prev_dnamelen, &prev_type, &prev_dclass, &rrset, section, region)) return LDNS_RCODE_SERVFAIL; if(!rrset) { /* it is a new RR set. hash&flags already calculated.*/ (*num_rrsets)++; rrset = new_rrset(msg, dname, dnamelen, type, dclass, hash, rrset_flags, section, region); if(!rrset) return LDNS_RCODE_SERVFAIL; } else if(0) { fprintf(stderr, "is part of existing: "); dname_print(stderr, pkt, rrset->dname); fprintf(stderr, " type %s(%d)\n", sldns_rr_descript(rrset->type)? sldns_rr_descript(rrset->type)->_name: "??", (int)rrset->type); } /* add to rrset. */ if((r=add_rr_to_rrset(rrset, pkt, msg, region, section, type)) != 0) return r; } return 0; }
/** * read contents of trusted-keys{ ... ; clauses and insert keys into storage. * @param anchors: where to store keys * @param buf: buffer to use * @param line: line number in file * @param in: file to read from. * @return 0 on error. */ static int process_bind_contents(struct val_anchors* anchors, sldns_buffer* buf, int* line, FILE* in) { /* loop over contents, collate strings before ; */ /* contents is (numbered): 0 1 2 3 4 5 6 7 8 */ /* name. 257 3 5 base64 base64 */ /* quoted value: 0 "111" 0 0 0 0 0 0 0 */ /* comments value: 1 "000" 1 1 1 "0 0 0 0" 1 */ int contnum = 0; int quoted = 0; int comments = 1; int rdlen; char* str = 0; sldns_buffer_clear(buf); while((rdlen=readkeyword_bindfile(in, buf, line, comments))) { if(rdlen == 1 && sldns_buffer_position(buf) == 1 && isspace((unsigned char)*sldns_buffer_begin(buf))) { /* starting whitespace is removed */ sldns_buffer_clear(buf); continue; } else if(rdlen == 1 && sldns_buffer_current(buf)[-1] == '"') { /* remove " from the string */ if(contnum == 0) { quoted = 1; comments = 0; } sldns_buffer_skip(buf, -1); if(contnum > 0 && quoted) { if(sldns_buffer_remaining(buf) < 8+1) { log_err("line %d, too long", *line); return 0; } sldns_buffer_write(buf, " DNSKEY ", 8); quoted = 0; comments = 1; } else if(contnum > 0) comments = !comments; continue; } else if(rdlen == 1 && sldns_buffer_current(buf)[-1] == ';') { if(contnum < 5) { sldns_buffer_write_u8(buf, 0); log_err("line %d, bad key", *line); return 0; } sldns_buffer_skip(buf, -1); sldns_buffer_write_u8(buf, 0); str = strdup((char*)sldns_buffer_begin(buf)); if(!str) { log_err("line %d, allocation failure", *line); return 0; } if(!anchor_store_str(anchors, buf, str)) { log_err("line %d, bad key", *line); free(str); return 0; } free(str); sldns_buffer_clear(buf); contnum = 0; quoted = 0; comments = 1; continue; } else if(rdlen == 1 && sldns_buffer_current(buf)[-1] == '}') { if(contnum > 0) { sldns_buffer_write_u8(buf, 0); log_err("line %d, bad key before }", *line); return 0; } return 1; } else if(rdlen == 1 && isspace((unsigned char)sldns_buffer_current(buf)[-1])) { /* leave whitespace here */ } else { /* not space or whatnot, so actual content */ contnum ++; if(contnum == 1 && !quoted) { if(sldns_buffer_remaining(buf) < 8+1) { log_err("line %d, too long", *line); return 0; } sldns_buffer_write(buf, " DNSKEY ", 8); } } } log_err("line %d, EOF before }", *line); return 0; }
/** * Read a keyword skipping bind comments; spaces, specials, restkeywords. * The file is split into the following tokens: * * special characters, on their own, rdlen=1, { } doublequote ; * * whitespace becomes a single ' ' or tab. Newlines become spaces. * * other words ('keywords') * * comments are skipped if desired * / / C++ style comment to end of line * # to end of line * / * C style comment * / * @param in: file to read from. * @param buf: buffer, what is read is stored after current buffer position. * Space is left in the buffer to write a terminating 0. * @param line: line number is increased per line, for error reports. * @param comments: if 0, comments are not possible and become text. * if 1, comments are skipped entirely. * In BIND files, this is when reading quoted strings, for example * " base 64 text with / / in there " * @return the number of character written to the buffer. * 0 on end of file. */ static int readkeyword_bindfile(FILE* in, sldns_buffer* buf, int* line, int comments) { int c; int numdone = 0; while((c = getc(in)) != EOF ) { if(comments && c == '#') { /* # blabla */ skip_to_eol(in); (*line)++; continue; } else if(comments && c=='/' && numdone>0 && /* /_/ bla*/ sldns_buffer_read_u8_at(buf, sldns_buffer_position(buf)-1) == '/') { sldns_buffer_skip(buf, -1); numdone--; skip_to_eol(in); (*line)++; continue; } else if(comments && c=='*' && numdone>0 && /* /_* bla *_/ */ sldns_buffer_read_u8_at(buf, sldns_buffer_position(buf)-1) == '/') { sldns_buffer_skip(buf, -1); numdone--; /* skip to end of comment */ while(c != EOF && (c=getc(in)) != EOF ) { if(c == '*') { if((c=getc(in)) == '/') break; } if(c == '\n') (*line)++; } continue; } /* not a comment, complete the keyword */ if(numdone > 0) { /* check same type */ if(isspace((unsigned char)c)) { ungetc(c, in); return numdone; } if(is_bind_special(c)) { ungetc(c, in); return numdone; } } if(c == '\n') { c = ' '; (*line)++; } /* space for 1 char + 0 string terminator */ if(sldns_buffer_remaining(buf) < 2) { fatal_exit("trusted-keys, %d, string too long", *line); } sldns_buffer_write_u8(buf, (uint8_t)c); numdone++; if(isspace((unsigned char)c)) { /* collate whitespace into ' ' */ while((c = getc(in)) != EOF ) { if(c == '\n') (*line)++; if(!isspace((unsigned char)c)) { ungetc(c, in); break; } } return numdone; } if(is_bind_special(c)) return numdone; } return numdone; }
/** do the rdata copy */ static int rdata_copy(sldns_buffer* pkt, struct packed_rrset_data* data, uint8_t* to, struct rr_parse* rr, time_t* rr_ttl, uint16_t type, sldns_pkt_section section) { uint16_t pkt_len; const sldns_rr_descriptor* desc; *rr_ttl = sldns_read_uint32(rr->ttl_data); /* RFC 2181 Section 8. if msb of ttl is set treat as if zero. */ if(*rr_ttl & 0x80000000U) *rr_ttl = 0; if(type == LDNS_RR_TYPE_SOA && section == LDNS_SECTION_AUTHORITY) { /* negative response. see if TTL of SOA record larger than the * minimum-ttl in the rdata of the SOA record */ if(*rr_ttl > soa_find_minttl(rr)) *rr_ttl = soa_find_minttl(rr); if(*rr_ttl > MAX_NEG_TTL) *rr_ttl = MAX_NEG_TTL; } if(*rr_ttl < MIN_TTL) *rr_ttl = MIN_TTL; if(*rr_ttl < data->ttl) data->ttl = *rr_ttl; if(rr->outside_packet) { /* uncompressed already, only needs copy */ memmove(to, rr->ttl_data+sizeof(uint32_t), rr->size); return 1; } sldns_buffer_set_position(pkt, (size_t) (rr->ttl_data - sldns_buffer_begin(pkt) + sizeof(uint32_t))); /* insert decompressed size into rdata len stored in memory */ /* -2 because rdatalen bytes are not included. */ pkt_len = htons(rr->size - 2); memmove(to, &pkt_len, sizeof(uint16_t)); to += 2; /* read packet rdata len */ pkt_len = sldns_buffer_read_u16(pkt); if(sldns_buffer_remaining(pkt) < pkt_len) return 0; desc = sldns_rr_descript(type); if(pkt_len > 0 && desc && desc->_dname_count > 0) { int count = (int)desc->_dname_count; int rdf = 0; size_t len; size_t oldpos; /* decompress dnames. */ while(pkt_len > 0 && count) { switch(desc->_wireformat[rdf]) { case LDNS_RDF_TYPE_DNAME: oldpos = sldns_buffer_position(pkt); dname_pkt_copy(pkt, to, sldns_buffer_current(pkt)); to += pkt_dname_len(pkt); pkt_len -= sldns_buffer_position(pkt)-oldpos; count--; len = 0; break; case LDNS_RDF_TYPE_STR: len = sldns_buffer_current(pkt)[0] + 1; break; default: len = get_rdf_size(desc->_wireformat[rdf]); break; } if(len) { memmove(to, sldns_buffer_current(pkt), len); to += len; sldns_buffer_skip(pkt, (ssize_t)len); log_assert(len <= pkt_len); pkt_len -= len; } rdf++; } } /* copy remaining rdata */ if(pkt_len > 0) memmove(to, sldns_buffer_current(pkt), pkt_len); return 1; }
int reply_info_encode(struct query_info* qinfo, struct reply_info* rep, uint16_t id, uint16_t flags, sldns_buffer* buffer, time_t timenow, struct regional* region, uint16_t udpsize, int dnssec) { uint16_t ancount=0, nscount=0, arcount=0; struct compress_tree_node* tree = 0; int r; size_t rr_offset; sldns_buffer_clear(buffer); if(udpsize < sldns_buffer_limit(buffer)) sldns_buffer_set_limit(buffer, udpsize); if(sldns_buffer_remaining(buffer) < LDNS_HEADER_SIZE) return 0; sldns_buffer_write(buffer, &id, sizeof(uint16_t)); sldns_buffer_write_u16(buffer, flags); sldns_buffer_write_u16(buffer, rep->qdcount); /* set an, ns, ar counts to zero in case of small packets */ sldns_buffer_write(buffer, "\000\000\000\000\000\000", 6); /* insert query section */ if(rep->qdcount) { if((r=insert_query(qinfo, &tree, buffer, region)) != RETVAL_OK) { if(r == RETVAL_TRUNC) { /* create truncated message */ sldns_buffer_write_u16_at(buffer, 4, 0); LDNS_TC_SET(sldns_buffer_begin(buffer)); sldns_buffer_flip(buffer); return 1; } return 0; } } /* roundrobin offset. using query id for random number. With ntohs * for different roundrobins for sequential id client senders. */ rr_offset = RRSET_ROUNDROBIN?ntohs(id):0; /* insert answer section */ if((r=insert_section(rep, rep->an_numrrsets, &ancount, buffer, 0, timenow, 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; } sldns_buffer_write_u16_at(buffer, 6, ancount); /* if response is positive answer, auth/add sections are not required */ if( ! (MINIMAL_RESPONSES && positive_answer(rep, qinfo->qtype)) ) { /* insert auth section */ if((r=insert_section(rep, rep->ns_numrrsets, &nscount, buffer, rep->an_numrrsets, timenow, region, &tree, LDNS_SECTION_AUTHORITY, qinfo->qtype, dnssec, rr_offset)) != RETVAL_OK) { if(r == RETVAL_TRUNC) { /* create truncated message */ sldns_buffer_write_u16_at(buffer, 8, nscount); LDNS_TC_SET(sldns_buffer_begin(buffer)); sldns_buffer_flip(buffer); return 1; } return 0; } sldns_buffer_write_u16_at(buffer, 8, nscount); /* insert add section */ if((r=insert_section(rep, rep->ar_numrrsets, &arcount, buffer, rep->an_numrrsets + rep->ns_numrrsets, timenow, region, &tree, LDNS_SECTION_ADDITIONAL, qinfo->qtype, dnssec, rr_offset)) != RETVAL_OK) { if(r == RETVAL_TRUNC) { /* no need to set TC bit, this is the additional */ sldns_buffer_write_u16_at(buffer, 10, arcount); sldns_buffer_flip(buffer); return 1; } return 0; } sldns_buffer_write_u16_at(buffer, 10, arcount); } sldns_buffer_flip(buffer); return 1; }
int reply_info_encode(struct query_info* qinfo, struct reply_info* rep, uint16_t id, uint16_t flags, sldns_buffer* buffer, time_t timenow, struct regional* region, uint16_t udpsize, int dnssec) { uint16_t ancount=0, nscount=0, arcount=0; struct compress_tree_node* tree = 0; int r; size_t rr_offset; sldns_buffer_clear(buffer); if(udpsize < sldns_buffer_limit(buffer)) sldns_buffer_set_limit(buffer, udpsize); if(sldns_buffer_remaining(buffer) < LDNS_HEADER_SIZE) return 0; sldns_buffer_write(buffer, &id, sizeof(uint16_t)); sldns_buffer_write_u16(buffer, flags); sldns_buffer_write_u16(buffer, rep->qdcount); /* set an, ns, ar counts to zero in case of small packets */ sldns_buffer_write(buffer, "\000\000\000\000\000\000", 6); /* insert query section */ if(rep->qdcount) { if((r=insert_query(qinfo, &tree, buffer, region)) != RETVAL_OK) { if(r == RETVAL_TRUNC) { /* create truncated message */ sldns_buffer_write_u16_at(buffer, 4, 0); LDNS_TC_SET(sldns_buffer_begin(buffer)); sldns_buffer_flip(buffer); return 1; } return 0; } } /* roundrobin offset. using query id for random number. With ntohs * 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, 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; } sldns_buffer_write_u16_at(buffer, 6, ancount); /* if response is positive answer, auth/add sections are not required */ if( ! (MINIMAL_RESPONSES && positive_answer(rep, qinfo->qtype)) ) { /* insert auth section */ if((r=insert_section(rep, rep->ns_numrrsets, &nscount, buffer, rep->an_numrrsets, timenow, region, &tree, LDNS_SECTION_AUTHORITY, qinfo->qtype, dnssec, rr_offset)) != RETVAL_OK) { if(r == RETVAL_TRUNC) { /* create truncated message */ sldns_buffer_write_u16_at(buffer, 8, nscount); LDNS_TC_SET(sldns_buffer_begin(buffer)); sldns_buffer_flip(buffer); return 1; } return 0; } sldns_buffer_write_u16_at(buffer, 8, nscount); /* insert add section */ if((r=insert_section(rep, rep->ar_numrrsets, &arcount, buffer, rep->an_numrrsets + rep->ns_numrrsets, timenow, region, &tree, LDNS_SECTION_ADDITIONAL, qinfo->qtype, dnssec, rr_offset)) != RETVAL_OK) { if(r == RETVAL_TRUNC) { /* no need to set TC bit, this is the additional */ sldns_buffer_write_u16_at(buffer, 10, arcount); sldns_buffer_flip(buffer); return 1; } return 0; } sldns_buffer_write_u16_at(buffer, 10, arcount); } sldns_buffer_flip(buffer); return 1; }
/** store rrset in buffer in wireformat, return RETVAL_* */ static int packed_rrset_encode(struct ub_packed_rrset_key* key, sldns_buffer* pkt, uint16_t* num_rrs, time_t timenow, struct regional* region, int do_data, int do_sig, struct compress_tree_node** tree, sldns_pkt_section s, uint16_t qtype, int dnssec, size_t rr_offset) { size_t i, j, owner_pos; int r, owner_labs; uint16_t owner_ptr = 0; struct packed_rrset_data* data = (struct packed_rrset_data*) key->entry.data; /* does this RR type belong in the answer? */ if(!rrset_belongs_in_reply(s, ntohs(key->rk.type), qtype, dnssec)) return RETVAL_OK; owner_labs = dname_count_labels(key->rk.dname); owner_pos = sldns_buffer_position(pkt); if(do_data) { const sldns_rr_descriptor* c = type_rdata_compressable(key); for(i=0; i<data->count; i++) { /* rrset roundrobin */ j = (i + rr_offset) % data->count; if((r=compress_owner(key, pkt, region, tree, owner_pos, &owner_ptr, owner_labs)) != RETVAL_OK) return r; sldns_buffer_write(pkt, &key->rk.type, 2); sldns_buffer_write(pkt, &key->rk.rrset_class, 2); if(data->rr_ttl[j] < timenow) sldns_buffer_write_u32(pkt, 0); else sldns_buffer_write_u32(pkt, data->rr_ttl[j]-timenow); if(c) { if((r=compress_rdata(pkt, data->rr_data[j], data->rr_len[j], region, tree, c)) != RETVAL_OK) return r; } else { if(sldns_buffer_remaining(pkt) < data->rr_len[j]) return RETVAL_TRUNC; sldns_buffer_write(pkt, data->rr_data[j], data->rr_len[j]); } } } /* insert rrsigs */ if(do_sig && dnssec) { size_t total = data->count+data->rrsig_count; for(i=data->count; i<total; i++) { if(owner_ptr && owner_labs != 1) { if(sldns_buffer_remaining(pkt) < 2+4+4+data->rr_len[i]) return RETVAL_TRUNC; sldns_buffer_write(pkt, &owner_ptr, 2); } else { if((r=compress_any_dname(key->rk.dname, pkt, owner_labs, region, tree)) != RETVAL_OK) return r; if(sldns_buffer_remaining(pkt) < 4+4+data->rr_len[i]) return RETVAL_TRUNC; } sldns_buffer_write_u16(pkt, LDNS_RR_TYPE_RRSIG); sldns_buffer_write(pkt, &key->rk.rrset_class, 2); if(data->rr_ttl[i] < timenow) sldns_buffer_write_u32(pkt, 0); else sldns_buffer_write_u32(pkt, data->rr_ttl[i]-timenow); /* rrsig rdata cannot be compressed, perform 100+ byte * memcopy. */ sldns_buffer_write(pkt, data->rr_data[i], data->rr_len[i]); } } /* change rrnum only after we are sure it fits */ if(do_data) *num_rrs += data->count; if(do_sig && dnssec) *num_rrs += data->rrsig_count; return RETVAL_OK; }