diff options
Diffstat (limited to '')
| -rw-r--r-- | daemon/lua/kres.lua | 1143 |
1 files changed, 1143 insertions, 0 deletions
diff --git a/daemon/lua/kres.lua b/daemon/lua/kres.lua new file mode 100644 index 0000000..4dc2b40 --- /dev/null +++ b/daemon/lua/kres.lua @@ -0,0 +1,1143 @@ +-- LuaJIT ffi bindings for libkres, a DNS resolver library. +-- SPDX-License-Identifier: GPL-3.0-or-later +-- +-- @note Since it's statically compiled, it expects to find the symbols in the C namespace. + +local kres -- the module + +local kluautil = require('kluautil') +local ffi = require('ffi') +local bit = require('bit') +local bor = bit.bor +local band = bit.band +local C = ffi.C +local knot = ffi.load(libknot_SONAME) + +-- Inverse table +local function itable(t, tolower) + local it = {} + for k,v in pairs(t) do it[v] = tolower and string.lower(k) or k end + return it +end + +-- Byte order conversions +local function htonl(x) return x end +local htons = htonl +if ffi.abi('le') then + htonl = bit.bswap + function htons(x) return bit.rshift(htonl(x), 16) end +end + +-- Basic types +local u16_p = ffi.typeof('uint16_t *') + +-- Various declarations that are very stable. +ffi.cdef[[ +/* + * Data structures + */ + +struct sockaddr { + uint16_t sa_family; + uint8_t _stub[]; /* Do not touch */ +}; + +struct knot_error { + int code; +}; + +/* + * libc APIs + */ +void * malloc(size_t size); +void free(void *ptr); +int inet_pton(int af, const char *src, void *dst); +int gettimeofday(struct timeval *tv, struct timezone *tz); +]] + +require('kres-gen') + +-- Error code representation +local knot_error_t = ffi.typeof('struct knot_error') +ffi.metatype(knot_error_t, { + -- Convert libknot error strings + __tostring = function(self) + return ffi.string(knot.knot_strerror(self.code)) + end, +}); + +-- Constant tables +local const_class = { + IN = 1, + CH = 3, + NONE = 254, + ANY = 255, +} +local const_type = { + A = 1, + NS = 2, + MD = 3, + MF = 4, + CNAME = 5, + SOA = 6, + MB = 7, + MG = 8, + MR = 9, + NULL = 10, + WKS = 11, + PTR = 12, + HINFO = 13, + MINFO = 14, + MX = 15, + TXT = 16, + RP = 17, + AFSDB = 18, + X25 = 19, + ISDN = 20, + RT = 21, + NSAP = 22, + ['NSAP-PTR'] = 23, + SIG = 24, + KEY = 25, + PX = 26, + GPOS = 27, + AAAA = 28, + LOC = 29, + NXT = 30, + EID = 31, + NIMLOC = 32, + SRV = 33, + ATMA = 34, + NAPTR = 35, + KX = 36, + CERT = 37, + A6 = 38, + DNAME = 39, + SINK = 40, + OPT = 41, + APL = 42, + DS = 43, + SSHFP = 44, + IPSECKEY = 45, + RRSIG = 46, + NSEC = 47, + DNSKEY = 48, + DHCID = 49, + NSEC3 = 50, + NSEC3PARAM = 51, + TLSA = 52, + SMIMEA = 53, + HIP = 55, + NINFO = 56, + RKEY = 57, + TALINK = 58, + CDS = 59, + CDNSKEY = 60, + OPENPGPKEY = 61, + CSYNC = 62, + ZONEMD = 63, + SVCB = 64, + HTTPS = 65, + + SPF = 99, + UINFO = 100, + UID = 101, + GID = 102, + UNSPEC = 103, + NID = 104, + L32 = 105, + L64 = 106, + LP = 107, + EUI48 = 108, + EUI64 = 109, + TKEY = 249, + TSIG = 250, + IXFR = 251, + AXFR = 252, + MAILB = 253, + MAILA = 254, + ANY = 255, + URI = 256, + CAA = 257, + AVC = 258, + DOA = 259, + TA = 32768, + DLV = 32769, +} +local const_section = { + ANSWER = 0, + AUTHORITY = 1, + ADDITIONAL = 2, +} +local const_opcode = { + QUERY = 0, + IQUERY = 1, + STATUS = 2, + NOTIFY = 4, + UPDATE = 5, +} +local const_rcode = { + NOERROR = 0, + FORMERR = 1, + SERVFAIL = 2, + NXDOMAIN = 3, + NOTIMPL = 4, + REFUSED = 5, + YXDOMAIN = 6, + YXRRSET = 7, + NXRRSET = 8, + NOTAUTH = 9, + NOTZONE = 10, + BADVERS = 16, + BADCOOKIE = 23, +} +-- This corresponds to `enum kr_rank`, it's not possible to do this without introspection unfortunately +local const_rank = { + INITIAL = 0, + OMIT = 1, + TRY = 2, + INDET = 4, + BOGUS = 5, + MISMATCH = 6, + MISSING = 7, + INSECURE = 8, + AUTH = 16, + SECURE = 32 +} +local const_extended_error = { + NONE = -1, + OTHER = 0, + DNSKEY_ALG = 1, + DS_DIGEST = 2, + STALE = 3, + FORGED = 4, + INDETERMINATE = 5, + BOGUS = 6, + SIG_EXPIRED = 7, + SIG_NOTYET = 8, + DNSKEY_MISS = 9, + RRSIG_MISS = 10, + DNSKEY_BIT = 11, + NSEC_MISS = 12, + CACHED_ERR = 13, + NOT_READY = 14, + BLOCKED = 15, + CENSORED = 16, + FILTERED = 17, + PROHIBITED = 18, + STALE_NXD = 19, + NOTAUTH = 20, + NOTSUP = 21, + NREACH_AUTH = 22, + NETWORK = 23, + INV_DATA = 24, +} + +-- Constant tables +local const_class_str = itable(const_class) +local const_type_str = itable(const_type) +local const_rcode_str = itable(const_rcode) +local const_opcode_str = itable(const_opcode) +local const_section_str = itable(const_section) +local const_rank_str = itable(const_rank) +local const_extended_error_str = itable(const_extended_error) + +-- Metatype for RR types to allow anonymous types +setmetatable(const_type, { + __index = function (t, k) + local v = rawget(t, k) + if v then return v end + -- Allow TYPE%d notation + if string.find(k, 'TYPE', 1, true) then + return tonumber(k:sub(5)) + end + -- Unknown type + return + end +}) + +-- Metatype for RR types to allow anonymous string types +setmetatable(const_type_str, { + __index = function (t, k) + local v = rawget(t, k) + if v then return v end + return string.format('TYPE%d', k) + end +}) + +-- Metatype for timeval +local timeval_t = ffi.typeof('struct timeval') + +-- Metatype for sockaddr +local addr_buf = ffi.new('char[16]') +local str_addr_buf = ffi.new('char[46 + 1 + 6 + 1]') -- INET6_ADDRSTRLEN + #port + \0 +local str_addr_buf_len = ffi.sizeof(str_addr_buf) +local sockaddr_t = ffi.typeof('struct sockaddr') +ffi.metatype( sockaddr_t, { + __index = { + len = function(sa) return C.kr_inaddr_len(sa) end, + ip = function (sa) return C.kr_inaddr(sa) end, + family = function (sa) return C.kr_inaddr_family(sa) end, + port = function (sa) return C.kr_inaddr_port(sa) end, + }, + __tostring = function(sa) + assert(ffi.istype(sockaddr_t, sa)) + local len = ffi.new('size_t[1]', str_addr_buf_len) + local ret = C.kr_inaddr_str(sa, str_addr_buf, len) + if ret ~= 0 then + error('kr_inaddr_str failed: ' .. tostring(ret)) + end + return ffi.string(str_addr_buf) + end, + +}) + +-- Parametrized LRU table +local typed_lru_t = 'struct { $ value_type[1]; struct lru * lru; }' + +-- Metatype for LRU +local lru_metatype = { + -- Create a new LRU with given value type + -- By default the LRU will have a capacity of 65536 elements + -- Note: At the point the parametrized type must be finalized + __new = function (ct, max_slots, alignment) + -- {0} will make sure that the value is coercible to a number + local o = ffi.new(ct, {0}, C.lru_create_impl(max_slots or 65536, alignment or 1, nil, nil)) + if o.lru == nil then + return + end + return o + end, + -- Destructor to clean allocated memory + __gc = function (self) + assert(self.lru ~= nil) + C.lru_free_items_impl(self.lru) + C.free(self.lru) + self.lru = nil + end, + __index = { + -- Look up key and return reference to current + -- Note: The key will be inserted if it doesn't exist + get_ref = function (self, key, key_len, allow_insert) + local insert = allow_insert and true or false + local ptr = C.lru_get_impl(self.lru, key, key_len or #key, ffi.sizeof(self.value_type[0]), insert, nil) + if ptr ~= nil then + return ffi.cast(self.value_type, ptr) + end + end, + -- Look up key and return current value + get = function (self, key, key_len) + local ref = self:get_ref(key, key_len, false) + if ref then + return ref[0] + end + end, + -- Set value for key to given value + set = function (self, key, value, key_len) + local ref = self:get_ref(key, key_len, true) + if ref then + ref[0] = value + return true + end + end, + }, +} + +-- Pretty print for domain name +local function dname2str(dname) + if dname == nil then return end + local text_name = ffi.gc(C.knot_dname_to_str(nil, dname, 0), C.free) + if text_name ~= nil then + return ffi.string(text_name) + end +end + +-- Convert dname pointer to wireformat string +local function dname2wire(name) + if name == nil then return nil end + return ffi.string(name, knot.knot_dname_size(name)) +end + +-- Parse RDATA, from presentation to wire-format. +-- in: a table of strings, each a line describing RRTYPE+RDATA +-- out: a table of RDATA strings in wire-format +local function parse_rdata(strs, nothing) + local zonefile = require('zonefile') + if type(strs) ~= 'table' or nothing ~= nil then -- accidents like forgetting braces + error('a table of string(s) is expected', 2) + end + local res = {} + for _, line in ipairs(strs) do + if type(line) ~= 'string' then + error('table must contain strings', 2) + end + local rrs = zonefile.string('. ' .. line) + if #rrs == 0 then error('failed to parse line: ' .. line, 2) end + for _, rr in ipairs(rrs) do + table.insert(res, rr.rdata) + end + end + return res +end + +-- RR sets created in Lua must have a destructor to release allocated memory +local function rrset_free(rr) + if rr._owner ~= nil then ffi.C.free(rr._owner) end + if rr:rdcount() > 0 then ffi.C.free(rr.rrs.rdata) end +end + +-- Metatype for RR set. Beware, the indexing is 0-based (rdata, get, tostring). +local rrset_buflen = (64 + 1) * 1024 +local rrset_buf = ffi.new('char[?]', rrset_buflen) +local knot_rrset_pt = ffi.typeof('knot_rrset_t *') +local knot_rrset_t = ffi.typeof('knot_rrset_t') +ffi.metatype( knot_rrset_t, { + -- Create a new empty RR set object with an allocated owner and a destructor + __new = function (ct, owner, rrtype, rrclass, ttl) + local rr = ffi.new(ct) + C.kr_rrset_init(rr, + owner and knot.knot_dname_copy(owner, nil), + rrtype or 0, + rrclass or const_class.IN, + ttl or 0) + return ffi.gc(rr, rrset_free) + end, + -- BEWARE: `owner` and `rdata` are typed as a plain lua strings + -- and not the real types they represent. + __tostring = function(rr) + assert(ffi.istype(knot_rrset_t, rr)) + return rr:txt_dump() + end, + __index = { + owner = function(rr) + assert(ffi.istype(knot_rrset_t, rr)) + return dname2wire(rr._owner) + end, + ttl = function(rr) + assert(ffi.istype(knot_rrset_t, rr)) + return tonumber(rr._ttl) + end, + class = function(rr, val) + assert(ffi.istype(knot_rrset_t, rr)) + if val then + rr.rclass = val + end + return tonumber(rr.rclass) + end, + rdata_pt = function(rr, i) + assert(ffi.istype(knot_rrset_t, rr) and i >= 0 and i < rr:rdcount()) + return knot.knot_rdataset_at(rr.rrs, i) + end, + rdata = function(rr, i) + assert(ffi.istype(knot_rrset_t, rr)) + local rd = rr:rdata_pt(i) + return ffi.string(rd.data, rd.len) + end, + get = function(rr, i) + assert(ffi.istype(knot_rrset_t, rr) and i >= 0 and i < rr:rdcount()) + return {owner = rr:owner(), + ttl = rr:ttl(), + class = tonumber(rr.rclass), + type = tonumber(rr.type), + rdata = rr:rdata(i)} + end, + tostring = function(rr, i) + assert(ffi.istype(knot_rrset_t, rr) + and (i == nil or (i >= 0 and i < rr:rdcount())) ) + if rr:rdcount() > 0 then + local ret + if i ~= nil then + ret = knot.knot_rrset_txt_dump_data(rr, i, rrset_buf, rrset_buflen, C.KR_DUMP_STYLE_DEFAULT) + else + ret = -1 + end + return ret >= 0 and ffi.string(rrset_buf) + end + end, + + -- Dump the rrset in presentation format (dig-like). + txt_dump = function(rr, style) + assert(ffi.istype(knot_rrset_t, rr)) + local bufsize = 1024 + local dump = ffi.new('char *[1]', C.malloc(bufsize)) + -- ^ one pointer to a string + local size = ffi.new('size_t[1]', { bufsize }) -- one size_t = bufsize + + local ret = knot.knot_rrset_txt_dump(rr, dump, size, + style or C.KR_DUMP_STYLE_DEFAULT) + local result = nil + if ret >= 0 then + result = ffi.string(dump[0], ret) + end + C.free(dump[0]) + return result + end, + txt_fields = function(rr, i) + assert(ffi.istype(knot_rrset_t, rr)) + assert(i >= 0 and i < rr:rdcount()) + local bufsize = 1024 + local dump = ffi.new('char *', C.malloc(bufsize)) + ffi.gc(dump, C.free) + + local ret = knot.knot_rrset_txt_dump_data(rr, i, dump, 1024, + C.KR_DUMP_STYLE_DEFAULT) + if ret >= 0 then + local out = {} + out.owner = dname2str(rr:owner()) + out.ttl = rr:ttl() + out.class = kres.tostring.class[rr:class()] + out.type = kres.tostring.type[rr.type] + out.rdata = ffi.string(dump, ret) + return out + else + panic('knot_rrset_txt_dump_data failure ' .. tostring(ret)) + end + end, + -- Return RDATA count for this RR set + rdcount = function(rr) + assert(ffi.istype(knot_rrset_t, rr)) + return tonumber(rr.rrs.count) + end, + -- Add binary RDATA to the RR set + add_rdata = function (rr, rdata, rdlen, no_ttl) + assert(ffi.istype(knot_rrset_t, rr)) + assert(no_ttl == nil, 'add_rdata() can not accept TTL anymore') + local ret = knot.knot_rrset_add_rdata(rr, rdata, tonumber(rdlen), nil) + if ret ~= 0 then return nil, knot_error_t(ret) end + return true + end, + -- Merge data from another RR set into the current one + merge_rdata = function (rr, source) + assert(ffi.istype(knot_rrset_t, rr)) + assert(ffi.istype(knot_rrset_t, source)) + local ret = knot.knot_rdataset_merge(rr.rrs, source.rrs, nil) + if ret ~= 0 then return nil, knot_error_t(ret) end + return true + end, + -- Return type covered by this RRSIG + type_covered = function(rr, i) + i = i or 0 + assert(ffi.istype(knot_rrset_t, rr) and i >= 0 and i < rr:rdcount()) + if rr.type ~= const_type.RRSIG then return end + return tonumber(C.kr_rrsig_type_covered(knot.knot_rdataset_at(rr.rrs, i))) + end, + -- Check whether a RRSIG is covering current RR set + is_covered_by = function(rr, rrsig) + assert(ffi.istype(knot_rrset_t, rr)) + assert(ffi.istype(knot_rrset_t, rrsig)) + assert(rrsig.type == const_type.RRSIG) + return (rr.type == rrsig:type_covered() and rr:owner() == rrsig:owner()) + end, + -- Return RR set wire size + wire_size = function(rr) + assert(ffi.istype(knot_rrset_t, rr)) + return tonumber(knot.knot_rrset_size(rr)) + end, + }, +}) + +-- Destructor for packet accepts pointer to pointer +local knot_pkt_t = ffi.typeof('knot_pkt_t') + +-- Helpers for reading/writing 16-bit numbers from packet wire +local function pkt_u16(pkt, off, val) + assert(ffi.istype(knot_pkt_t, pkt)) + local ptr = ffi.cast(u16_p, pkt.wire + off) + if val ~= nil then ptr[0] = htons(val) end + return (htons(ptr[0])) +end + +-- Helpers for reading/writing message header flags +local function pkt_bit(pkt, byteoff, bitmask, val) + -- If the value argument is passed, set/clear the desired bit + if val ~= nil then + if val then pkt.wire[byteoff] = bit.bor(pkt.wire[byteoff], bitmask) + else pkt.wire[byteoff] = bit.band(pkt.wire[byteoff], bit.bnot(bitmask)) end + return true + end + return (bit.band(pkt.wire[byteoff], bitmask) ~= 0) +end + +local function knot_pkt_rr(section, i) + assert(section and ffi.istype('knot_pktsection_t', section) + and i >= 0 and i < section.count) + local ret = section.pkt.rr + section.pos + i + assert(ffi.istype(knot_rrset_pt, ret)) + return ret +end + +-- Metatype for packet +ffi.metatype( knot_pkt_t, { + __new = function (_, size, wire) + if size < 12 or size > 65535 then + error('packet size must be <12, 65535>') + end + + local pkt = knot.knot_pkt_new(nil, size, nil) + if pkt == nil then + error(string.format('failed to allocate a packet of size %d', size)) + end + if wire == nil then + C.kr_rnd_buffered(pkt.wire, 2) -- randomize the query ID + else + assert(size <= #wire) + ffi.copy(pkt.wire, wire, size) + pkt.size = size + pkt.parsed = 0 + end + + return ffi.gc(pkt[0], knot.knot_pkt_free) + end, + __tostring = function(pkt) + return pkt:tostring() + end, + __len = function(pkt) + assert(ffi.istype(knot_pkt_t, pkt)) + return tonumber(pkt.size) + end, + __ipairs = function(self) + return ipairs(self:section(const_section.ANSWER)) + end, + __index = { + -- Header + id = function(pkt, val) return pkt_u16(pkt, 0, val) end, + qdcount = function(pkt, val) return pkt_u16(pkt, 4, val) end, + ancount = function(pkt, val) return pkt_u16(pkt, 6, val) end, + nscount = function(pkt, val) return pkt_u16(pkt, 8, val) end, + arcount = function(pkt, val) return pkt_u16(pkt, 10, val) end, + opcode = function (pkt, val) + assert(ffi.istype(knot_pkt_t, pkt)) + pkt.wire[2] = (val) and bit.bor(bit.band(pkt.wire[2], 0x78), 8 * val) or pkt.wire[2] + return (bit.band(pkt.wire[2], 0x78) / 8) + end, + rcode = function (pkt, val) + assert(ffi.istype(knot_pkt_t, pkt)) + pkt.wire[3] = (val) and bor(band(pkt.wire[3], 0xf0), val) or pkt.wire[3] + return band(pkt.wire[3], 0x0f) + end, + rd = function (pkt, val) return pkt_bit(pkt, 2, 0x01, val) end, + tc = function (pkt, val) return pkt_bit(pkt, 2, 0x02, val) end, + aa = function (pkt, val) return pkt_bit(pkt, 2, 0x04, val) end, + qr = function (pkt, val) return pkt_bit(pkt, 2, 0x80, val) end, + cd = function (pkt, val) return pkt_bit(pkt, 3, 0x10, val) end, + ad = function (pkt, val) return pkt_bit(pkt, 3, 0x20, val) end, + ra = function (pkt, val) return pkt_bit(pkt, 3, 0x80, val) end, + -- "do" is a reserved word in Lua; only getter + dobit = function(pkt, val) + assert(val == nil, 'dobit is getter only') + assert(ffi.istype(knot_pkt_t, pkt)) + return C.kr_pkt_has_dnssec(pkt) + end, + -- Question + qname = function(pkt) + assert(ffi.istype(knot_pkt_t, pkt)) + -- inlined knot_pkt_qname(), basically but not lower-cased + if pkt == nil or pkt.qname_size == 0 then return nil end + return ffi.string(pkt.wire + 12, pkt.qname_size) + end, + qclass = function(pkt) + assert(ffi.istype(knot_pkt_t, pkt)) + return C.kr_pkt_qclass(pkt) + end, + qtype = function(pkt) + assert(ffi.istype(knot_pkt_t, pkt)) + return C.kr_pkt_qtype(pkt) + end, + rrsets = function (pkt, section_id) + assert(ffi.istype(knot_pkt_t, pkt)) + local records = {} + local section = pkt.sections + section_id + for i = 1, section.count do + local rrset = knot_pkt_rr(section, i - 1) + table.insert(records, rrset) + end + return records + end, + section = function (pkt, section_id) + assert(ffi.istype(knot_pkt_t, pkt)) + local records = {} + local section = pkt.sections + section_id + for i = 1, section.count do + local rrset = knot_pkt_rr(section, i - 1) + for k = 1, rrset:rdcount() do + table.insert(records, rrset:get(k - 1)) + end + end + return records + end, + begin = function (pkt, section) + assert(ffi.istype(knot_pkt_t, pkt)) + assert(section >= pkt.current, 'cannot rewind to already written section') + assert(const_section_str[section], string.format('invalid section: %s', section)) + local ret = knot.knot_pkt_begin(pkt, section) + if ret ~= 0 then return nil, knot_error_t(ret) end + return true + end, + put = function (pkt, owner, ttl, rclass, rtype, rdata) + assert(ffi.istype(knot_pkt_t, pkt)) + local ret = C.kr_pkt_put(pkt, owner, ttl, rclass, rtype, rdata, #rdata) + if ret ~= 0 then return nil, knot_error_t(ret) end + return true + end, + -- Put an RR set in the packet + -- Note: the packet doesn't take ownership of the RR set + put_rr = function (pkt, rr, rotate, flags) + assert(ffi.istype(knot_pkt_t, pkt)) + assert(ffi.istype(knot_rrset_t, rr)) + local ret = C.knot_pkt_put_rotate(pkt, 0, rr, rotate or 0, flags or 0) + if ret ~= 0 then return nil, knot_error_t(ret) end + return true + end, + -- Checks whether the packet has a wire, i.e. the .size is not + -- equal to KR_PKT_SIZE_NOWIRE + has_wire = function (pkt) + assert(ffi.istype(knot_pkt_t, pkt)) + return C.kr_pkt_has_wire(pkt) + end, + recycle = function (pkt) + assert(ffi.istype(knot_pkt_t, pkt)) + local ret = C.kr_pkt_recycle(pkt) + if ret ~= 0 then return nil, knot_error_t(ret) end + return true + end, + clear_payload = function (pkt) + assert(ffi.istype(knot_pkt_t, pkt)) + local ret = C.kr_pkt_clear_payload(pkt) + if ret ~= 0 then return nil, knot_error_t(ret) end + return true + end, + question = function(pkt, qname, qclass, qtype) + assert(ffi.istype(knot_pkt_t, pkt)) + assert(qclass ~= nil, string.format('invalid class: %s', qclass)) + assert(qtype ~= nil, string.format('invalid type: %s', qtype)) + local ret = C.knot_pkt_put_question(pkt, qname, qclass, qtype) + if ret ~= 0 then return nil, knot_error_t(ret) end + return true + end, + towire = function (pkt) + assert(ffi.istype(knot_pkt_t, pkt)) + return ffi.string(pkt.wire, pkt.size) + end, + tostring = function(pkt) + assert(ffi.istype(knot_pkt_t, pkt)) + return ffi.string(ffi.gc(C.kr_pkt_text(pkt), C.free)) + end, + -- Return number of remaining empty bytes in the packet + -- This is generally useful to check if there's enough space + remaining_bytes = function (pkt) + assert(ffi.istype(knot_pkt_t, pkt)) + local occupied = pkt.size + pkt.reserved + assert(pkt.max_size >= occupied) + return tonumber(pkt.max_size - occupied) + end, + -- Packet manipulation + parse = function (pkt) + assert(ffi.istype(knot_pkt_t, pkt)) + local ret = knot.knot_pkt_parse(pkt, 0) + if ret ~= 0 then return nil, knot_error_t(ret) end + return true + end, + -- Resize packet wire to a new size + resize = function (pkt, new_size) + assert(ffi.istype(knot_pkt_t, pkt)) + local ptr = C.mm_realloc(pkt.mm, pkt.wire, new_size, pkt.max_size) + if ptr == nil then return end + pkt.wire = ptr + pkt.max_size = new_size + return true + end, + }, +}) +-- Metatype for query +local kr_query_t = ffi.typeof('struct kr_query') +ffi.metatype( kr_query_t, { + __index = { + -- Return query domain name + name = function(qry) + assert(ffi.istype(kr_query_t, qry)) + return dname2wire(qry.sname) + end, + -- Write this query into packet + write = function(qry, pkt) + assert(ffi.istype(kr_query_t, qry)) + assert(ffi.istype(knot_pkt_t, pkt)) + local ret = C.kr_make_query(qry, pkt) + if ret ~= 0 then return nil, knot_error_t(ret) end + return true + end, + }, +}) + +-- helper for trace_chain_callbacks +-- ignores return values from successful calls but logs tracebacks for throws +local function void_xpcall_log_tb(func, req, msg) + local ok, err = xpcall(func, debug.traceback, req, msg) + if not ok then + log_error(ffi.C.LOG_GRP_SYSTEM, 'callback %s req %s msg %s stack traceback:\n%s', func, req, msg, err) + end +end + +local function void_xpcall_finish_tb(func, req) + local ok, err = xpcall(func, debug.traceback, req) + if not ok then + log_error(ffi.C.LOG_GRP_SYSTEM, 'callback %s req %s stack traceback:\n%s', func, req, err) + end +end + + +-- Metatype for request +local kr_request_t = ffi.typeof('struct kr_request') +ffi.metatype( kr_request_t, { + __index = { + -- makes sense only when request is finished + all_from_cache = function(req) + assert(ffi.istype(kr_request_t, req)) + local rplan = ffi.C.kr_resolve_plan(req) + if tonumber(rplan.pending.len) > 0 then + -- an unresolved query, + -- i.e. something is missing from the cache + return false + end + for idx=0, tonumber(rplan.resolved.len) - 1 do + if not rplan.resolved.at[idx].flags.CACHED then + return false + end + end + return true + end, + current = function(req) + assert(ffi.istype(kr_request_t, req)) + if req.current_query == nil then return nil end + return req.current_query + end, + -- returns the initial query that started the request + initial = function(req) + assert(ffi.istype(kr_request_t, req)) + local rplan = C.kr_resolve_plan(req) + if rplan.initial == nil then return nil end + return rplan.initial + end, + -- Return last query on the resolution plan + last = function(req) + assert(ffi.istype(kr_request_t, req)) + local query = C.kr_rplan_last(C.kr_resolve_plan(req)) + if query == nil then return end + return query + end, + resolved = function(req) + assert(ffi.istype(kr_request_t, req)) + local qry = C.kr_rplan_resolved(C.kr_resolve_plan(req)) + if qry == nil then return nil end + return qry + end, + -- returns first resolved sub query for a request + first_resolved = function(req) + assert(ffi.istype(kr_request_t, req)) + local rplan = C.kr_resolve_plan(req) + if not rplan or rplan.resolved.len < 1 then return nil end + return rplan.resolved.at[0] + end, + push = function(req, qname, qtype, qclass, flags, parent) + assert(ffi.istype(kr_request_t, req)) + flags = kres.mk_qflags(flags) -- compatibility + local rplan = C.kr_resolve_plan(req) + local qry = C.kr_rplan_push(rplan, parent, qname, qclass, qtype) + if qry ~= nil and flags ~= nil then + C.kr_qflags_set(qry.flags, flags) + end + return qry + end, + pop = function(req, qry) + assert(ffi.istype(kr_request_t, req)) + return C.kr_rplan_pop(C.kr_resolve_plan(req), qry) + end, + selected_tostring = function(req) + assert(ffi.istype(kr_request_t, req)) + local buf = {} + if #req.answ_selected ~= 0 then + table.insert(buf, ';; selected from ANSWER sections:\n') + table.insert(buf, tostring(req.answ_selected)) + end + if #req.auth_selected ~= 0 then + table.insert(buf, ';; selected from AUTHORITY sections:\n') + table.insert(buf, tostring(req.auth_selected)) + end + if #req.add_selected ~= 0 then + table.insert(buf, ';; selected from ADDITIONAL sections:\n') + table.insert(buf, tostring(req.add_selected)) + end + return table.concat(buf, '') + end, + set_extended_error = function(req, code, msg) + assert(ffi.istype(kr_request_t, req)) + msg = kluautil.kr_string2c(msg, req.pool) + ffi.C.kr_request_set_extended_error(req, code, msg) + end, + + -- chain new callbacks after the old ones + -- creates new wrapper functions as necessary + -- note: callbacks are FFI cdata pointers so tests must + -- use explicit "cb == nil", just "if cb" does not work + -- + trace_chain_callbacks = function (req, new_log, new_finish) + local log_wrapper + if req.trace_log == nil then + req.trace_log = new_log + else + local old_log = req.trace_log + log_wrapper = ffi.cast('trace_log_f', + function(cbreq, msg) + jit.off(true, true) -- JIT for (C -> lua)^2 nesting isn't allowed + void_xpcall_log_tb(old_log, cbreq, msg) + void_xpcall_log_tb(new_log, cbreq, msg) + end) + req.trace_log = log_wrapper + end + local old_finish = req.trace_finish + if not (log_wrapper ~= nil or old_finish ~= nil) then + req.trace_finish = new_finish + else + local fin_wrapper + fin_wrapper = ffi.cast('trace_callback_f', + function(cbreq) + jit.off(true, true) -- JIT for (C -> lua)^2 nesting isn't allowed + if old_finish ~= nil then + void_xpcall_finish_tb(old_finish, cbreq) + end + if new_finish ~= nil then + void_xpcall_finish_tb(new_finish, cbreq) + end + -- beware: finish callbacks can call log callback + if log_wrapper ~= nil then + log_wrapper:free() + end + fin_wrapper:free() + end) + req.trace_finish = fin_wrapper + end + end, + + -- Return per-request variable table + -- The request can store anything in this Lua table and it will be freed + -- when the request is closed, it doesn't have to worry about contents. + vars = function (req) + assert(ffi.istype(kr_request_t, req)) + -- Return variable if it's already stored + local var = worker.vars[req.vars_ref] + if var then + return var + end + -- Either take a slot number from freelist + -- or find a first free slot (expand the table) + local ref = worker.vars[0] + if ref then + worker.vars[0] = worker.vars[ref] + else + ref = #worker.vars + 1 + end + -- Create new variables table + var = {} + worker.vars[ref] = var + -- Save reference in the request + req.vars_ref = ref + return var + end, + -- Ensure that answer has EDNS if needed; can't fail. + ensure_edns = function (req) + assert(ffi.istype(kr_request_t, req)) + return C.kr_request_ensure_edns(req) + end, + -- Ensure that answer exists and return it; can't fail. + ensure_answer = function (req) + assert(ffi.istype(kr_request_t, req)) + return C.kr_request_ensure_answer(req) + end, + }, +}) + +-- C array iterator +local function c_array_iter(t, i) + i = i + 1 + if i >= t.len then return end + return i, t.at[i][0] +end + +-- Metatype for a single ranked record array entry (one RRset) +local function rank_tostring(rank) + local names = {} + for name, value in pairs(const_rank) do + if ffi.C.kr_rank_test(rank, value) then + table.insert(names, string.lower(name)) + end + end + table.sort(names) -- pairs() above doesn't give a stable ordering + return string.format('0%.2o (%s)', rank, table.concat(names, ' ')) +end + +local ranked_rr_array_entry_t = ffi.typeof('ranked_rr_array_entry_t') +ffi.metatype(ranked_rr_array_entry_t, { + __tostring = function(self) + return string.format('; ranked rrset to_wire %s, rank %s, cached %s, qry_uid %s, revalidations %s\n%s', + self.to_wire, rank_tostring(self.rank), self.cached, self.qry_uid, + self.revalidation_cnt, string.format('%s', self.rr)) + end +}) + +-- Metatype for ranked record array (array of RRsets) +local ranked_rr_array_t = ffi.typeof('ranked_rr_array_t') +ffi.metatype(ranked_rr_array_t, { + __len = function(self) + return tonumber(self.len) + end, + __ipairs = function (self) + return c_array_iter, self, -1 + end, + __index = { + get = function (self, i) + if i < 0 or i > self.len then return nil end + return self.at[i][0] + end, + }, + __tostring = function(self) + local buf = {} + for _, rrset in ipairs(self) do + table.insert(buf, tostring(rrset)) + end + return table.concat(buf, '') + end +}) + +-- Cache metatype +local kr_cache_t = ffi.typeof('struct kr_cache') +ffi.metatype( kr_cache_t, { + __index = { + insert = function (self, rr, rrsig, rank, timestamp) + assert(ffi.istype(kr_cache_t, self)) + assert(ffi.istype(knot_rrset_t, rr), 'RR must be a rrset type') + assert(not rrsig or ffi.istype(knot_rrset_t, rrsig), 'RRSIG must be nil or of the rrset type') + -- Get current timestamp + if not timestamp then + local now = timeval_t() + C.gettimeofday(now, nil) + timestamp = tonumber(now.tv_sec) + end + -- Insert record into cache + local ret = C.kr_cache_insert_rr(self, rr, rrsig, tonumber(rank or 0), + timestamp, true) + if ret ~= 0 then return nil, knot_error_t(ret) end + return true + end, + commit = function (self) + assert(ffi.istype(kr_cache_t, self)) + local ret = C.kr_cache_commit(self) + if ret ~= 0 then return nil, knot_error_t(ret) end + return true + end, + }, +}) + +-- Pretty-print a single RR (which is a table with .owner .ttl .type .rdata) +-- Extension: append .comment if exists. +local function rr2str(rr, style) + -- Construct a single-RR temporary set while minimizing copying. + local ret + do + local rrs = knot_rrset_t(rr.owner, rr.type, kres.class.IN, rr.ttl) + rrs:add_rdata(rr.rdata, #rr.rdata) + ret = rrs:txt_dump(style) + end + + -- Trim the newline and append comment (optionally). + if ret then + if ret:byte(-1) == string.byte('\n', -1) then + ret = ret:sub(1, -2) + end + if rr.comment then + ret = ret .. ' ;' .. rr.comment + end + end + return ret +end + +-- Module API +kres = { + -- Constants + class = const_class, + type = const_type, + section = const_section, + rcode = const_rcode, + opcode = const_opcode, + rank = const_rank, + extended_error = const_extended_error, + + -- Constants to strings + tostring = { + class = const_class_str, + type = const_type_str, + section = const_section_str, + rcode = const_rcode_str, + opcode = const_opcode_str, + rank = const_rank_str, + extended_eror = const_extended_error_str, + }, + + -- Create a struct kr_qflags from a single flag name or a list of names. + mk_qflags = function (names) + local kr_qflags = ffi.typeof('struct kr_qflags') + if names == 0 or names == nil then -- compatibility: nil is common in lua + names = {} + elseif type(names) == 'string' then + names = {names} + elseif ffi.istype(kr_qflags, names) then + return names + end + + local fs = ffi.new(kr_qflags) + for _, name in pairs(names) do + fs[name] = true + end + return fs + end, + + CONSUME = 1, PRODUCE = 2, DONE = 4, FAIL = 8, YIELD = 16, + + -- Export types + rrset = knot_rrset_t, + packet = knot_pkt_t, + lru = function (max_size, value_type) + value_type = value_type or ffi.typeof('uint64_t') + local ct = ffi.typeof(typed_lru_t, value_type) + return ffi.metatype(ct, lru_metatype)(max_size, ffi.alignof(value_type)) + end, + + -- Metatypes. Beware that any pointer will be cast silently... + pkt_t = function (udata) return ffi.cast('knot_pkt_t *', udata) end, + request_t = function (udata) return ffi.cast('struct kr_request *', udata) end, + sockaddr_t = function (udata) return ffi.cast('struct sockaddr *', udata) end, + + -- Global API functions + -- Convert a lua string to a lower-case wire format (inside GC-ed ffi.string). + str2dname = function(name) + if type(name) ~= 'string' then return end + local dname = ffi.gc(C.knot_dname_from_str(nil, name, 0), C.free) + if dname == nil then return nil end + ffi.C.knot_dname_to_lower(dname); + return dname2wire(dname) + end, + dname2str = dname2str, + dname2wire = dname2wire, + parse_rdata = parse_rdata, + + rr2str = rr2str, + str2ip = function (ip) + local family = C.kr_straddr_family(ip) + local ret = C.inet_pton(family, ip, addr_buf) + if ret ~= 1 then return nil end + return ffi.string(addr_buf, C.kr_family_len(family)) + end, + context = function () return ffi.C.the_worker.engine.resolver end, + + knot_pkt_rr = knot_pkt_rr, +} + +return kres |