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author | Kim Alvefur <zash@zash.se> | 2020-10-04 21:29:44 +0200 |
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committer | Kim Alvefur <zash@zash.se> | 2020-10-04 21:29:44 +0200 |
commit | b657d2ab26259909d97a055a0ddba5f2f6f85d24 (patch) | |
tree | 36c363ab612049d2003619020a720a6337f48c87 /util | |
parent | 29238183e9fd345cd0e60eeb59cfe179223cc3ea (diff) | |
download | prosody-b657d2ab26259909d97a055a0ddba5f2f6f85d24.tar.gz prosody-b657d2ab26259909d97a055a0ddba5f2f6f85d24.zip |
util.dns: Implement SVCB record parser
Based on draft-ietf-dnsop-svcb-https-00
Diffstat (limited to 'util')
-rw-r--r-- | util/dns.lua | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/util/dns.lua b/util/dns.lua index f086f2c1..851f480e 100644 --- a/util/dns.lua +++ b/util/dns.lua @@ -198,6 +198,60 @@ function parsers.TLSA(packet) }, tlsa_mt); end +local svcb_params = {"alpn"; "no-default-alpn"; "port"; "ipv4hint"; "echconfig"; "ipv6hint"}; +setmetatable(svcb_params, {__index = function(_, n) return "key" .. tostring(n); end}); + +local svcb_mt = { + __tostring = function (rr) + local kv = {}; + for i = 1, #rr.fields do + t_insert(kv, s_format("%s=%q", svcb_params[rr.fields[i].key], tostring(rr.fields[i].value))); + end + return s_format("%d %s %s", rr.prio, rr.name, t_concat(kv, " ")); + end; +}; +local svbc_ip_mt = {__tostring = function(ip) return t_concat(ip, ", "); end} + +function parsers.SVCB(packet) + local prio_h, prio_l = packet:byte(1,2); + local prio = prio_h*256+prio_l; + local name, pos = readDnsName(packet, 3); + local fields = {}; + while #packet > pos do + local key_h, key_l = packet:byte(pos+0,pos+1); + local len_h, len_l = packet:byte(pos+2,pos+3); + local key = key_h*256+key_l; + local len = len_h*256+len_l; + local value = packet:sub(pos+4,pos+4-1+len) + if key == 1 then + value = setmetatable(parsers.TXT(value), svbc_ip_mt); + elseif key == 3 then + local port_h, port_l = value:byte(1,2); + local port = port_h*256+port_l; + value = port; + elseif key == 4 then + local ip = {}; + for i = 1, #value, 4 do + t_insert(ip, parsers.A(value:sub(i, i+3))); + end + value = setmetatable(ip, svbc_ip_mt); + elseif key == 6 then + local ip = {}; + for i = 1, #value, 16 do + t_insert(ip, parsers.AAAA(value:sub(i, i+15))); + end + value = setmetatable(ip, svbc_ip_mt); + end + t_insert(fields, { key = key, value = value, len = len }); + pos = pos+len+4; + end + return setmetatable({ + prio = prio, name = name, fields = fields, + }, svcb_mt); +end + +parsers.HTTPS = parsers.SVCB; + local params = { TLSA = { use = tlsa_usages; |