community
/
dns
3
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

[zone parser] disallow nested $GENERATE directive (#1033) 

While the range number of GENERATE is now limited, one can pass
a line with 2 $GENERATE directive that will exponentially increase the
time spent generating RRs.
Limit to only one per line.
Fixes #1020
This commit is contained in:
chantra 2019-10-23 02:41:32 -07:00 committed by Miek Gieben
parent 4d4363a5dc
commit 9b7437f11d
3 changed files with 10 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
generate.go
View File

@ -85,6 +85,7 @@ func (zp *ZoneParser) generate(l lex) (RR, bool) {
}
zp.sub = NewZoneParser(r, zp.origin, zp.file)
zp.sub.includeDepth, zp.sub.includeAllowed = zp.includeDepth, zp.includeAllowed
zp.sub.generateDisallowed = true
zp.sub.SetDefaultTTL(defaultTtl)
return zp.subNext()
}

5
generate_test.go
View File

@ -61,6 +61,10 @@ $GENERATE 0-1/0 dhcp-${0,4,d} A 10.0.0.$
`, true},
{`@ IN SOA ns.test. hostmaster.test. ( 1 8h 2h 7d 1d )
$GENERATE 0-1 $$INCLUDE ` + tmpdir + string(filepath.Separator) + `${0,4,d}.conf
`, false},
{`@ IN SOA ns.test. hostmaster.test. ( 1 8h 2h 7d 1d )
$GENERATE 0-1 dhcp-${0,4,d} A 10.0.0.$
$GENERATE 0-2 dhcp-${0,4,d} A 10.1.0.$
`, false},
}
Outer:
@ -214,6 +218,7 @@ func TestCrasherString(t *testing.T) {
{"$GENERATE 0-5414137360", "bad range in $GENERATE"},
{"$GENERATE 11522-3668518066406258", "bad range in $GENERATE"},
{"$GENERATE 0-200\"(;00000000000000\n$$GENERATE 0-0", "dns: garbage after $GENERATE range: \"\\\"\" at line: 1:16"},
{"$GENERATE 6-2048 $$GENERATE 6-036160 $$$$ORIGIN \\$", `dns: nested $GENERATE directive not allowed: "6-036160" at line: 1:19`},
}
for _, tc := range tests {
t.Run(tc.in, func(t *testing.T) {

4
scan.go
View File

@ -248,6 +248,7 @@ type ZoneParser struct {
includeDepth uint8
includeAllowed bool
generateDisallowed bool
}
// NewZoneParser returns an RFC 1035 style zonefile parser that reads
@ -547,6 +548,9 @@ func (zp *ZoneParser) Next() (RR, bool) {
st = zExpectDirGenerate
case zExpectDirGenerate:
if zp.generateDisallowed {
return zp.setParseError("nested $GENERATE directive not allowed", l)
}
if l.value != zString {
return zp.setParseError("expecting $GENERATE value, not this...", l)
}