From 2c598dcaec88956e9a2b4944ddef78e8be0a8676 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Deuc=D0=B5?= <shurd@sasktel.net>
Date: Sun, 4 Apr 2021 21:14:51 -0400
Subject: [PATCH] Change default failures to 3 and timeout to 5sec
Also, check that the opcode and response flag are correct when
parsing responses.
When handling a resolve call, ensure no errors occured.
---
exec/load/dns.js | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)
diff --git a/exec/load/dns.js b/exec/load/dns.js
index 0f3693244b..d7e730232b 100644
--- a/exec/load/dns.js
+++ b/exec/load/dns.js
@@ -403,12 +403,16 @@ DNS.prototype.handle_response = function(sock) {
ret.id = id;
ret.response = !!(ascii(resp[2]) & 1);
+ if (!ret.response)
+ return null;
ret.opcode = (ascii(resp[2]) & 0x1e) >> 1;
+ if (ret.opcode !== 0)
+ return null;
ret.authoritative = !!(ascii(resp[2]) & (1<<5));
ret.truncation = !!(ascii(resp[2]) & (1<<6));
ret.recusrion = !!(ascii(resp[2]) & (1<<7));
ret.reserved = ascii(resp[3]) & 7;
- ret.rcode = ascii(resp[3] & 0xf1) >> 3;
+ ret.rcode = ascii(resp[3] & 0xf0) >> 4;
queries = string_to_int16(resp.substr(4, 2));
answers = string_to_int16(resp.substr(6, 2));
@@ -498,9 +502,9 @@ DNS.prototype.asynchronous_query = function(queries, /* queryStr, type, class, *
if (recursive === undefined)
recursive = true;
if (timeout === undefined)
- timeout = 1000;
+ timeout = 5000;
if (failures === undefined)
- failures = 1;
+ failures = 3;
if (failed === undefined)
failed = 0;
@@ -539,9 +543,9 @@ DNS.prototype.synchronous_query = function(queries, callback, thisObj, recursive
if (recursive === undefined)
recursive = true;
if (timeout === undefined)
- timeout = 1000;
+ timeout = 5000;
if (failures === undefined)
- failures = 1;
+ failures = 3;
if (failed === undefined)
failed = 0;
@@ -717,6 +721,8 @@ DNS.prototype.resolveTypeClass = function(host, type, class, callback, thisObj)
resp.answers.forEach(function(ans) {
if (resp.queries[0].type != ans.type || resp.queries[0].class != ans.class)
return;
+ if (resp.rcode !== 0)
+ return;
this.ret.push(ans.rdata);
}, this);
}
--
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