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feat(dns): add a method type_name
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Signed-off-by: Jianhui Zhao <zhaojh329@gmail.com>
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@zhaojh329
zhaojh329 committed Sep 16, 2023
1 parent 4e74fbc commit 1e82ef6
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Showing 2 changed files with 61 additions and 57 deletions.
90 changes: 45 additions & 45 deletions dns.lua
View file
Original file line number Diff line number Diff line change
Expand Up @@ -5,38 +5,21 @@

local socket = require 'eco.socket'

local TYPE_A = 1
local TYPE_NS = 2
local TYPE_CNAME = 5
local TYPE_SOA = 6
local TYPE_PTR = 12
local TYPE_MX = 15
local TYPE_TXT = 16
local TYPE_AAAA = 28
local TYPE_SRV = 33
local TYPE_SPF = 99

local CLASS_IN = 1

local SECTION_AN = 1
local SECTION_NS = 2
local SECTION_AR = 3

local M = {
TYPE_A = TYPE_A,
TYPE_NS = TYPE_NS,
TYPE_CNAME = TYPE_CNAME,
TYPE_SOA = TYPE_SOA,
TYPE_PTR = TYPE_PTR,
TYPE_MX = TYPE_MX,
TYPE_TXT = TYPE_TXT,
TYPE_AAAA = TYPE_AAAA,
TYPE_SRV = TYPE_SRV,
TYPE_SPF = TYPE_SPF,
CLASS_IN = CLASS_IN,
SECTION_AN = SECTION_AN,
SECTION_NS = SECTION_NS,
SECTION_AR = SECTION_AR
TYPE_A = 1,
TYPE_NS = 2,
TYPE_CNAME = 5,
TYPE_SOA = 6,
TYPE_PTR = 12,
TYPE_MX = 15,
TYPE_TXT = 16,
TYPE_AAAA = 28,
TYPE_SRV = 33,
TYPE_SPF = 99,
CLASS_IN = 1,
SECTION_AN = 1,
SECTION_NS = 2,
SECTION_AR = 3
}

local resolver_errstrs = {
Expand Down Expand Up @@ -103,7 +86,7 @@ local function build_request(qname, id, opts)
end)

return string.pack('>I2I2I2I2I2I2zI2I2',
id, flags, nqs, nan, nns, nar, name, opts.type or TYPE_A, CLASS_IN)
id, flags, nqs, nan, nns, nar, name, opts.type or M.TYPE_A, M.CLASS_IN)
end

local function decode_name(buf, pos)
Expand Down Expand Up @@ -179,7 +162,7 @@ local function parse_section(answers, section, buf, start_pos, size)

pos = pos + 10

if typ == TYPE_A then
if typ == M.TYPE_A then

if len ~= 4 then
return nil, 'bad A record value length: ' .. len
Expand All @@ -192,7 +175,7 @@ local function parse_section(answers, section, buf, start_pos, size)

pos = pos + 4

elseif typ == TYPE_CNAME then
elseif typ == M.TYPE_CNAME then

local cname, p = decode_name(buf, pos)
if not cname then
Expand All @@ -207,7 +190,7 @@ local function parse_section(answers, section, buf, start_pos, size)

ans.cname = cname

elseif typ == TYPE_AAAA then
elseif typ == M.TYPE_AAAA then

if len ~= 16 then
return nil, 'bad AAAA record value length: ' .. len
Expand All @@ -232,7 +215,7 @@ local function parse_section(answers, section, buf, start_pos, size)

pos = pos + 16

elseif typ == TYPE_MX then
elseif typ == M.TYPE_MX then

if len < 3 then
return nil, 'bad MX record value length: ' .. len
Expand All @@ -253,7 +236,7 @@ local function parse_section(answers, section, buf, start_pos, size)

pos = p

elseif typ == TYPE_SRV then
elseif typ == M.TYPE_SRV then
if len < 7 then
return nil, 'bad SRV record value length: ' .. len
end
Expand All @@ -273,7 +256,7 @@ local function parse_section(answers, section, buf, start_pos, size)

pos = p

elseif typ == TYPE_NS then
elseif typ == M.TYPE_NS then
local name, p = decode_name(buf, pos)
if not name then
return nil, pos
Expand All @@ -287,8 +270,8 @@ local function parse_section(answers, section, buf, start_pos, size)

ans.nsdname = name

elseif typ == TYPE_TXT or typ == TYPE_SPF then
local key = typ == TYPE_TXT and 'txt' or 'spf'
elseif typ == M.TYPE_TXT or typ == M.TYPE_SPF then
local key = typ == M.TYPE_TXT and 'txt' or 'spf'

local slen = string.byte(buf, pos)
if slen + 1 > len then
Expand Down Expand Up @@ -324,7 +307,7 @@ local function parse_section(answers, section, buf, start_pos, size)

ans[key] = val

elseif typ == TYPE_PTR then
elseif typ == M.TYPE_PTR then
local name, p = decode_name(buf, pos)
if not name then
return nil, pos
Expand All @@ -338,7 +321,7 @@ local function parse_section(answers, section, buf, start_pos, size)

ans.ptrdname = name

elseif typ == TYPE_SOA then
elseif typ == M.TYPE_SOA then
local name, p = decode_name(buf, pos)
if not name then
return nil, pos
Expand Down Expand Up @@ -421,7 +404,7 @@ local function parse_response(buf, id)

local err

pos, err = parse_section(answers, SECTION_AN, buf, pos, nan)
pos, err = parse_section(answers, M.SECTION_AN, buf, pos, nan)

if not pos then
return nil, err
Expand Down Expand Up @@ -461,14 +444,14 @@ function M.query(qname, opts)

if socket.is_ipv4_address(qname) then
return { {
type = TYPE_A,
type = M.TYPE_A,
address = qname
} }
end

if socket.is_ipv6_address(qname) then
return { {
type = TYPE_AAAA,
type = M.TYPE_AAAA,
address = qname
} }
end
Expand Down Expand Up @@ -545,4 +528,21 @@ function M.query(qname, opts)
return nil, err
end

function M.type_name(n)
local names = {
[M.TYPE_A] = 'A',
[M.TYPE_NS] = 'NS',
[M.TYPE_CNAME] = 'CNAME',
[M.TYPE_SOA] = 'SOA',
[M.TYPE_PTR] = 'PTR',
[M.TYPE_MX] = 'MX',
[M.TYPE_TXT] = 'TXT',
[M.TYPE_AAAA] = 'AAAA',
[M.TYPE_SRV] = 'SRV',
[M.TYPE_SPF] = 'SPF'
}

return names[n] or 'unknown'
end

return M
28 changes: 16 additions & 12 deletions examples/network/dns.lua
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2,28 +2,32 @@

local dns = require 'eco.dns'

local function print_answer(prefix, answers)
print(prefix)

for _, a in ipairs(answers) do
for k, v in pairs(a) do
if k == 'type' then
v = dns.type_name(v)
end
print(k, v)
end
print()
end
end

local answers, err = dns.query('bing.com')
if not answers then
print('query fail:', err)
return
end

for _, a in ipairs(answers) do
for k, v in pairs(a) do
print(k, v)
end
print()
end
print_answer('-----IPv4-----', answers)

answers, err = dns.query('bing.com', { type = dns.TYPE_AAAA })
if not answers then
print('query fail:', err)
return
end

for _, a in ipairs(answers) do
for k, v in pairs(a) do
print(k, v)
end
print()
end
print_answer('-----IPv6-----', answers)

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