diff options
Diffstat (limited to 'test/dns-proto.cc')
-rw-r--r-- | test/dns-proto.cc | 634 |
1 files changed, 634 insertions, 0 deletions
diff --git a/test/dns-proto.cc b/test/dns-proto.cc new file mode 100644 index 0000000..8814d28 --- /dev/null +++ b/test/dns-proto.cc @@ -0,0 +1,634 @@ +#include "dns-proto.h" + +// Include ares internal file for DNS protocol details +#include "ares.h" +#include "ares_dns.h" + +#include <sstream> + +namespace ares { + +std::string HexDump(std::vector<byte> data) { + std::stringstream ss; + for (size_t ii = 0; ii < data.size(); ii++) { + char buffer[2 + 1]; + sprintf(buffer, "%02x", data[ii]); + ss << buffer; + } + return ss.str(); +} + +std::string HexDump(const byte *data, int len) { + return HexDump(std::vector<byte>(data, data + len)); +} + +std::string HexDump(const char *data, int len) { + return HexDump(reinterpret_cast<const byte*>(data), len); +} + +std::string StatusToString(int status) { + switch (status) { + case ARES_SUCCESS: return "ARES_SUCCESS"; + case ARES_ENODATA: return "ARES_ENODATA"; + case ARES_EFORMERR: return "ARES_EFORMERR"; + case ARES_ESERVFAIL: return "ARES_ESERVFAIL"; + case ARES_ENOTFOUND: return "ARES_ENOTFOUND"; + case ARES_ENOTIMP: return "ARES_ENOTIMP"; + case ARES_EREFUSED: return "ARES_EREFUSED"; + case ARES_EBADQUERY: return "ARES_EBADQUERY"; + case ARES_EBADNAME: return "ARES_EBADNAME"; + case ARES_EBADFAMILY: return "ARES_EBADFAMILY"; + case ARES_EBADRESP: return "ARES_EBADRESP"; + case ARES_ECONNREFUSED: return "ARES_ECONNREFUSED"; + case ARES_ETIMEOUT: return "ARES_ETIMEOUT"; + case ARES_EOF: return "ARES_EOF"; + case ARES_EFILE: return "ARES_EFILE"; + case ARES_ENOMEM: return "ARES_ENOMEM"; + case ARES_EDESTRUCTION: return "ARES_EDESTRUCTION"; + case ARES_EBADSTR: return "ARES_EBADSTR"; + case ARES_EBADFLAGS: return "ARES_EBADFLAGS"; + case ARES_ENONAME: return "ARES_ENONAME"; + case ARES_EBADHINTS: return "ARES_EBADHINTS"; + case ARES_ENOTINITIALIZED: return "ARES_ENOTINITIALIZED"; + case ARES_ELOADIPHLPAPI: return "ARES_ELOADIPHLPAPI"; + case ARES_EADDRGETNETWORKPARAMS: return "ARES_EADDRGETNETWORKPARAMS"; + case ARES_ECANCELLED: return "ARES_ECANCELLED"; + default: return "UNKNOWN"; + } +} + +std::string RcodeToString(int rcode) { + switch (rcode) { + case ns_r_noerror: return "NOERROR"; + case ns_r_formerr: return "FORMERR"; + case ns_r_servfail: return "SERVFAIL"; + case ns_r_nxdomain: return "NXDOMAIN"; + case ns_r_notimpl: return "NOTIMPL"; + case ns_r_refused: return "REFUSED"; + case ns_r_yxdomain: return "YXDOMAIN"; + case ns_r_yxrrset: return "YXRRSET"; + case ns_r_nxrrset: return "NXRRSET"; + case ns_r_notauth: return "NOTAUTH"; + case ns_r_notzone: return "NOTZONE"; + case ns_r_badsig: return "BADSIG"; + case ns_r_badkey: return "BADKEY"; + case ns_r_badtime: return "BADTIME"; + default: return "UNKNOWN"; + } +} + +std::string RRTypeToString(int rrtype) { + switch (rrtype) { + case ns_t_a: return "A"; + case ns_t_ns: return "NS"; + case ns_t_md: return "MD"; + case ns_t_mf: return "MF"; + case ns_t_cname: return "CNAME"; + case ns_t_soa: return "SOA"; + case ns_t_mb: return "MB"; + case ns_t_mg: return "MG"; + case ns_t_mr: return "MR"; + case ns_t_null: return "NULL"; + case ns_t_wks: return "WKS"; + case ns_t_ptr: return "PTR"; + case ns_t_hinfo: return "HINFO"; + case ns_t_minfo: return "MINFO"; + case ns_t_mx: return "MX"; + case ns_t_txt: return "TXT"; + case ns_t_rp: return "RP"; + case ns_t_afsdb: return "AFSDB"; + case ns_t_x25: return "X25"; + case ns_t_isdn: return "ISDN"; + case ns_t_rt: return "RT"; + case ns_t_nsap: return "NSAP"; + case ns_t_nsap_ptr: return "NSAP_PTR"; + case ns_t_sig: return "SIG"; + case ns_t_key: return "KEY"; + case ns_t_px: return "PX"; + case ns_t_gpos: return "GPOS"; + case ns_t_aaaa: return "AAAA"; + case ns_t_loc: return "LOC"; + case ns_t_nxt: return "NXT"; + case ns_t_eid: return "EID"; + case ns_t_nimloc: return "NIMLOC"; + case ns_t_srv: return "SRV"; + case ns_t_atma: return "ATMA"; + case ns_t_naptr: return "NAPTR"; + case ns_t_kx: return "KX"; + case ns_t_cert: return "CERT"; + case ns_t_a6: return "A6"; + case ns_t_dname: return "DNAME"; + case ns_t_sink: return "SINK"; + case ns_t_opt: return "OPT"; + case ns_t_apl: return "APL"; + case ns_t_ds: return "DS"; + case ns_t_sshfp: return "SSHFP"; + case ns_t_rrsig: return "RRSIG"; + case ns_t_nsec: return "NSEC"; + case ns_t_dnskey: return "DNSKEY"; + case ns_t_tkey: return "TKEY"; + case ns_t_tsig: return "TSIG"; + case ns_t_ixfr: return "IXFR"; + case ns_t_axfr: return "AXFR"; + case ns_t_mailb: return "MAILB"; + case ns_t_maila: return "MAILA"; + case ns_t_any: return "ANY"; + case ns_t_zxfr: return "ZXFR"; + case ns_t_max: return "MAX"; + default: return "UNKNOWN"; + } +} + +std::string ClassToString(int qclass) { + switch (qclass) { + case ns_c_in: return "IN"; + case ns_c_chaos: return "CHAOS"; + case ns_c_hs: return "HESIOD"; + case ns_c_none: return "NONE"; + case ns_c_any: return "ANY"; + default: return "UNKNOWN"; + } +} + +std::string AddressToString(const void* vaddr, int len) { + const byte* addr = reinterpret_cast<const byte*>(vaddr); + std::stringstream ss; + if (len == 4) { + char buffer[4*4 + 3 + 1]; + sprintf(buffer, "%u.%u.%u.%u", + (unsigned char)addr[0], + (unsigned char)addr[1], + (unsigned char)addr[2], + (unsigned char)addr[3]); + ss << buffer; + } else if (len == 16) { + for (int ii = 0; ii < 16; ii+=2) { + if (ii > 0) ss << ':'; + char buffer[4 + 1]; + sprintf(buffer, "%02x%02x", (unsigned char)addr[ii], (unsigned char)addr[ii+1]); + ss << buffer; + } + } else { + ss << "!" << HexDump(addr, len) << "!"; + } + return ss.str(); +} + +std::string PacketToString(const std::vector<byte>& packet) { + const byte* data = packet.data(); + int len = packet.size(); + std::stringstream ss; + if (len < NS_HFIXEDSZ) { + ss << "(too short, len " << len << ")"; + return ss.str(); + } + ss << ((DNS_HEADER_QR(data) == 0) ? "REQ " : "RSP "); + switch (DNS_HEADER_OPCODE(data)) { + case ns_o_query: ss << "QRY "; break; + case ns_o_iquery: ss << "IQRY "; break; + case ns_o_status: ss << "STATUS "; break; + case ns_o_notify: ss << "NOTIFY "; break; + case ns_o_update: ss << "UPDATE "; break; + default: ss << "UNKNOWN(" << DNS_HEADER_OPCODE(data) << ") "; break; + } + if (DNS_HEADER_AA(data)) ss << "AA "; + if (DNS_HEADER_TC(data)) ss << "TC "; + if (DNS_HEADER_RD(data)) ss << "RD "; + if (DNS_HEADER_RA(data)) ss << "RA "; + if (DNS_HEADER_Z(data)) ss << "Z "; + if (DNS_HEADER_QR(data) == 1) ss << RcodeToString(DNS_HEADER_RCODE(data)); + + int nquestions = DNS_HEADER_QDCOUNT(data); + int nanswers = DNS_HEADER_ANCOUNT(data); + int nauths = DNS_HEADER_NSCOUNT(data); + int nadds = DNS_HEADER_ARCOUNT(data); + + const byte* pq = data + NS_HFIXEDSZ; + len -= NS_HFIXEDSZ; + for (int ii = 0; ii < nquestions; ii++) { + ss << " Q:" << QuestionToString(packet, &pq, &len); + } + const byte* prr = pq; + for (int ii = 0; ii < nanswers; ii++) { + ss << " A:" << RRToString(packet, &prr, &len); + } + for (int ii = 0; ii < nauths; ii++) { + ss << " AUTH:" << RRToString(packet, &prr, &len); + } + for (int ii = 0; ii < nadds; ii++) { + ss << " ADD:" << RRToString(packet, &prr, &len); + } + return ss.str(); +} + +std::string QuestionToString(const std::vector<byte>& packet, + const byte** data, int* len) { + std::stringstream ss; + ss << "{"; + if (*len < NS_QFIXEDSZ) { + ss << "(too short, len " << *len << ")"; + return ss.str(); + } + + char *name = nullptr; + long enclen; + int rc = ares_expand_name(*data, packet.data(), packet.size(), &name, &enclen); + if (rc != ARES_SUCCESS) { + ss << "(error from ares_expand_name)"; + return ss.str(); + } + if (enclen > *len) { + ss << "(error, encoded name len " << enclen << "bigger than remaining data " << *len << " bytes)"; + return ss.str(); + } + *len -= enclen; + *data += enclen; + ss << "'" << name << "' "; + free(name); + if (*len < NS_QFIXEDSZ) { + ss << "(too short, len left " << *len << ")"; + return ss.str(); + } + ss << ClassToString(DNS_QUESTION_CLASS(*data)) << " "; + ss << RRTypeToString(DNS_QUESTION_TYPE(*data)); + *data += NS_QFIXEDSZ; + *len -= NS_QFIXEDSZ; + ss << "}"; + return ss.str(); +} + +std::string RRToString(const std::vector<byte>& packet, + const byte** data, int* len) { + std::stringstream ss; + ss << "{"; + if (*len < NS_RRFIXEDSZ) { + ss << "too short, len " << *len << ")"; + return ss.str(); + } + + char *name = nullptr; + long enclen; + int rc = ares_expand_name(*data, packet.data(), packet.size(), &name, &enclen); + if (rc != ARES_SUCCESS) { + ss << "(error from ares_expand_name)"; + return ss.str(); + } + if (enclen > *len) { + ss << "(error, encoded name len " << enclen << "bigger than remaining data " << *len << " bytes)"; + return ss.str(); + } + *len -= enclen; + *data += enclen; + ss << "'" << name << "' "; + free(name); + name = nullptr; + + if (*len < NS_RRFIXEDSZ) { + ss << "(too short, len left " << *len << ")"; + return ss.str(); + } + int rrtype = DNS_RR_TYPE(*data); + if (rrtype == ns_t_opt) { + ss << "MAXUDP=" << DNS_RR_CLASS(*data) << " "; + ss << RRTypeToString(rrtype) << " "; + ss << "RCODE2=" << DNS_RR_TTL(*data); + } else { + ss << ClassToString(DNS_RR_CLASS(*data)) << " "; + ss << RRTypeToString(rrtype) << " "; + ss << "TTL=" << DNS_RR_TTL(*data); + } + int rdatalen = DNS_RR_LEN(*data); + + *data += NS_RRFIXEDSZ; + *len -= NS_RRFIXEDSZ; + if (*len < rdatalen) { + ss << "(RR too long at " << rdatalen << ", len left " << *len << ")"; + } else { + switch (rrtype) { + case ns_t_a: + case ns_t_aaaa: + ss << " " << AddressToString(*data, rdatalen); + break; + case ns_t_txt: { + const byte* p = *data; + while (p < (*data + rdatalen)) { + int len = *p++; + if ((p + len) <= (*data + rdatalen)) { + std::string txt(p, p + len); + ss << " " << len << ":'" << txt << "'"; + } else { + ss << "(string too long)"; + } + p += len; + } + break; + } + case ns_t_cname: + case ns_t_ns: + case ns_t_ptr: { + int rc = ares_expand_name(*data, packet.data(), packet.size(), &name, &enclen); + if (rc != ARES_SUCCESS) { + ss << "(error from ares_expand_name)"; + break; + } + ss << " '" << name << "'"; + free(name); + break; + } + case ns_t_mx: + if (rdatalen > 2) { + int rc = ares_expand_name(*data + 2, packet.data(), packet.size(), &name, &enclen); + if (rc != ARES_SUCCESS) { + ss << "(error from ares_expand_name)"; + break; + } + ss << " " << DNS__16BIT(*data) << " '" << name << "'"; + free(name); + } else { + ss << "(RR too short)"; + } + break; + case ns_t_srv: { + if (rdatalen > 6) { + const byte* p = *data; + unsigned long prio = DNS__16BIT(p); + unsigned long weight = DNS__16BIT(p + 2); + unsigned long port = DNS__16BIT(p + 4); + p += 6; + int rc = ares_expand_name(p, packet.data(), packet.size(), &name, &enclen); + if (rc != ARES_SUCCESS) { + ss << "(error from ares_expand_name)"; + break; + } + ss << prio << " " << weight << " " << port << " '" << name << "'"; + free(name); + } else { + ss << "(RR too short)"; + } + break; + } + case ns_t_soa: { + const byte* p = *data; + int rc = ares_expand_name(p, packet.data(), packet.size(), &name, &enclen); + if (rc != ARES_SUCCESS) { + ss << "(error from ares_expand_name)"; + break; + } + ss << " '" << name << "'"; + free(name); + p += enclen; + rc = ares_expand_name(p, packet.data(), packet.size(), &name, &enclen); + if (rc != ARES_SUCCESS) { + ss << "(error from ares_expand_name)"; + break; + } + ss << " '" << name << "'"; + free(name); + p += enclen; + if ((p + 20) <= (*data + rdatalen)) { + unsigned long serial = DNS__32BIT(p); + unsigned long refresh = DNS__32BIT(p + 4); + unsigned long retry = DNS__32BIT(p + 8); + unsigned long expire = DNS__32BIT(p + 12); + unsigned long minimum = DNS__32BIT(p + 16); + ss << " " << serial << " " << refresh << " " << retry << " " << expire << " " << minimum; + } else { + ss << "(RR too short)"; + } + break; + } + case ns_t_naptr: { + if (rdatalen > 7) { + const byte* p = *data; + unsigned long order = DNS__16BIT(p); + unsigned long pref = DNS__16BIT(p + 2); + p += 4; + ss << order << " " << pref; + + int len = *p++; + std::string flags(p, p + len); + ss << " " << flags; + p += len; + + len = *p++; + std::string service(p, p + len); + ss << " '" << service << "'"; + p += len; + + len = *p++; + std::string regexp(p, p + len); + ss << " '" << regexp << "'"; + p += len; + + int rc = ares_expand_name(p, packet.data(), packet.size(), &name, &enclen); + if (rc != ARES_SUCCESS) { + ss << "(error from ares_expand_name)"; + break; + } + ss << " '" << name << "'"; + free(name); + } else { + ss << "(RR too short)"; + } + break; + } + default: + ss << " " << HexDump(*data, rdatalen); + break; + } + } + *data += rdatalen; + *len -= rdatalen; + + ss << "}"; + return ss.str(); +} + +void PushInt32(std::vector<byte>* data, int value) { + data->push_back((value & 0xff000000) >> 24); + data->push_back((value & 0x00ff0000) >> 16); + data->push_back((value & 0x0000ff00) >> 8); + data->push_back(value & 0x000000ff); +} + +void PushInt16(std::vector<byte>* data, int value) { + data->push_back((value & 0xff00) >> 8); + data->push_back(value & 0x00ff); +} + +std::vector<byte> EncodeString(const std::string& name) { + std::vector<byte> data; + std::stringstream ss(name); + std::string label; + // TODO: cope with escapes + while (std::getline(ss, label, '.')) { + data.push_back(label.length()); + data.insert(data.end(), label.begin(), label.end()); + } + data.push_back(0); + return data; +} + +std::vector<byte> DNSQuestion::data() const { + std::vector<byte> data; + std::vector<byte> encname = EncodeString(name_); + data.insert(data.end(), encname.begin(), encname.end()); + PushInt16(&data, rrtype_); + PushInt16(&data, qclass_); + return data; +} + +std::vector<byte> DNSRR::data() const { + std::vector<byte> data = DNSQuestion::data(); + PushInt32(&data, ttl_); + return data; +} + +std::vector<byte> DNSSingleNameRR::data() const { + std::vector<byte> data = DNSRR::data(); + std::vector<byte> encname = EncodeString(other_); + int len = encname.size(); + PushInt16(&data, len); + data.insert(data.end(), encname.begin(), encname.end()); + return data; +} + +std::vector<byte> DNSTxtRR::data() const { + std::vector<byte> data = DNSRR::data(); + int len = 0; + for (const std::string& txt : txt_) { + len += (1 + txt.size()); + } + PushInt16(&data, len); + for (const std::string& txt : txt_) { + data.push_back(txt.size()); + data.insert(data.end(), txt.begin(), txt.end()); + } + return data; +} + +std::vector<byte> DNSMxRR::data() const { + std::vector<byte> data = DNSRR::data(); + std::vector<byte> encname = EncodeString(other_); + int len = 2 + encname.size(); + PushInt16(&data, len); + PushInt16(&data, pref_); + data.insert(data.end(), encname.begin(), encname.end()); + return data; +} + +std::vector<byte> DNSSrvRR::data() const { + std::vector<byte> data = DNSRR::data(); + std::vector<byte> encname = EncodeString(target_); + int len = 6 + encname.size(); + PushInt16(&data, len); + PushInt16(&data, prio_); + PushInt16(&data, weight_); + PushInt16(&data, port_); + data.insert(data.end(), encname.begin(), encname.end()); + return data; +} + +std::vector<byte> DNSAddressRR::data() const { + std::vector<byte> data = DNSRR::data(); + int len = addr_.size(); + PushInt16(&data, len); + data.insert(data.end(), addr_.begin(), addr_.end()); + return data; +} + +std::vector<byte> DNSSoaRR::data() const { + std::vector<byte> data = DNSRR::data(); + std::vector<byte> encname1 = EncodeString(nsname_); + std::vector<byte> encname2 = EncodeString(rname_); + int len = encname1.size() + encname2.size() + 5*4; + PushInt16(&data, len); + data.insert(data.end(), encname1.begin(), encname1.end()); + data.insert(data.end(), encname2.begin(), encname2.end()); + PushInt32(&data, serial_); + PushInt32(&data, refresh_); + PushInt32(&data, retry_); + PushInt32(&data, expire_); + PushInt32(&data, minimum_); + return data; +} + +std::vector<byte> DNSOptRR::data() const { + std::vector<byte> data = DNSRR::data(); + int len = 0; + for (const DNSOption& opt : opts_) { + len += (4 + opt.data_.size()); + } + PushInt16(&data, len); + for (const DNSOption& opt : opts_) { + PushInt16(&data, opt.code_); + PushInt16(&data, opt.data_.size()); + data.insert(data.end(), opt.data_.begin(), opt.data_.end()); + } + return data; +} + +std::vector<byte> DNSNaptrRR::data() const { + std::vector<byte> data = DNSRR::data(); + std::vector<byte> encname = EncodeString(replacement_); + int len = (4 + 1 + flags_.size() + 1 + service_.size() + 1 + regexp_.size() + encname.size()); + PushInt16(&data, len); + PushInt16(&data, order_); + PushInt16(&data, pref_); + data.push_back(flags_.size()); + data.insert(data.end(), flags_.begin(), flags_.end()); + data.push_back(service_.size()); + data.insert(data.end(), service_.begin(), service_.end()); + data.push_back(regexp_.size()); + data.insert(data.end(), regexp_.begin(), regexp_.end()); + data.insert(data.end(), encname.begin(), encname.end()); + return data; +} + +std::vector<byte> DNSPacket::data() const { + std::vector<byte> data; + PushInt16(&data, qid_); + byte b = 0x00; + if (response_) b |= 0x80; + b |= ((opcode_ & 0x0f) << 3); + if (aa_) b |= 0x04; + if (tc_) b |= 0x02; + if (rd_) b |= 0x01; + data.push_back(b); + b = 0x00; + if (ra_) b |= 0x80; + if (z_) b |= 0x40; + if (ad_) b |= 0x20; + if (cd_) b |= 0x10; + b |= (rcode_ & 0x0f); + data.push_back(b); + + int count = questions_.size(); + PushInt16(&data, count); + count = answers_.size(); + PushInt16(&data, count); + count = auths_.size(); + PushInt16(&data, count); + count = adds_.size(); + PushInt16(&data, count); + + for (const std::unique_ptr<DNSQuestion>& question : questions_) { + std::vector<byte> qdata = question->data(); + data.insert(data.end(), qdata.begin(), qdata.end()); + } + for (const std::unique_ptr<DNSRR>& rr : answers_) { + std::vector<byte> rrdata = rr->data(); + data.insert(data.end(), rrdata.begin(), rrdata.end()); + } + for (const std::unique_ptr<DNSRR>& rr : auths_) { + std::vector<byte> rrdata = rr->data(); + data.insert(data.end(), rrdata.begin(), rrdata.end()); + } + for (const std::unique_ptr<DNSRR>& rr : adds_) { + std::vector<byte> rrdata = rr->data(); + data.insert(data.end(), rrdata.begin(), rrdata.end()); + } + return data; +} + +} // namespace ares |