These were flagged by GitHub CodeQL code scanning as potential
vulnerabilities or issues. Fixing them is easy and they are incorrect.
Adding tests is less easy because int is 64-bits on most systems,
including those we test on, so we can't consistently provoke a failure
here.
* fix check for bad offset on 32 bit systems
* parse integers into int64 rather than platform dependent ints
Co-authored-by: Michael Hudson-Doyle <Michael Hudson-Doyle michael.hudson@ubuntu.com>
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
* Limit $GENERATE range to 65535 steps
Having these checks means all test in TestCrasherString() are not
reached because we bail out earlier - removed that test all together.
Fixes#1019
Signed-off-by: Miek Gieben <miek@miek.nl>
* bring back testcase
Signed-off-by: Miek Gieben <miek@miek.nl>
* bring back crash test
Signed-off-by: Miek Gieben <miek@miek.nl>
* [fuzz] Fix crashes when parsing GENERATE
Running the fuzzer on NewRR, some crashes came up that could be
prevented by checking that the token after the range is a Blank.
This diff checks that and return an error when the blank is not found.
* * s/Expect blank /garbage /
* get rid of if/else
* Improve ParseZone tests
* Add new ZoneParser API
* Use the ZoneParser API directly in ReadRR
* Merge parseZoneHelper into ParseZone
* Make generate string building slightly more efficient
* Add SetDefaultTTL method to ZoneParser
This makes it possible for external consumers to implement ReadRR.
* Make $INCLUDE directive opt-in
The $INCLUDE directive opens a user controlled file and parses it as
a DNS zone file. The error messages may reveal portions of sensitive
files, such as:
/etc/passwd: dns: not a TTL: "root❌0:0:root:/root:/bin/bash" at line: 1:31
/etc/shadow: dns: not a TTL: "root:$6$<redacted>::0:99999:7:::" at line: 1:125
Both ParseZone and ReadRR are currently opt-in for backward
compatibility.
* Disable $INCLUDE support in ReadRR
ReadRR and NewRR are often passed untrusted input. At the same time,
$INCLUDE isn't really useful for ReadRR as it only ever returns the
first record.
This is a breaking change, but it currently represents a slight
security risk.
* Document the need to drain the ParseZone chan
* Cleanup the documentation of NewRR, ReadRR and ParseZone
* Document the ZoneParser API
* Deprecated the ParseZone function
* Add whitespace to ZoneParser.Next
* Remove prevName field from ZoneParser
This doesn't track anything meaningful as both zp.prevName and h.Name
are only ever set at the same point and to the same value.
* Use uint8 for ZoneParser.include field
It has a maximum value of 7 which easily fits within uint8.
This reduces the size of ZoneParser from 160 bytes to 152 bytes.
* Add setParseError helper to ZoneParser
* Surface $INCLUDE os.Open error in error message
* Rename ZoneParser.include field to includeDepth
* Make maximum $INCLUDE depth a const
* Add ParseZone and ZoneParser benchmarks
* Parse $GENERATE directive with a single ZoneParser
This should be more efficient than calling NewRR for each generated
record.
* Run go fmt on generate_test.go
* Add a benchmark for $GENERATE directives
* Use a custom reader for generate
This avoids the overhead and memory usage of building the zone string.
name old time/op new time/op delta
Generate-12 165µs ± 4% 157µs ± 2% -5.06% (p=0.000 n=25+25)
name old alloc/op new alloc/op delta
Generate-12 42.1kB ± 0% 31.8kB ± 0% -24.42% (p=0.000 n=20+23)
name old allocs/op new allocs/op delta
Generate-12 1.56k ± 0% 1.55k ± 0% -0.38% (p=0.000 n=25+25)
* Return correct ParseError from generateReader
The last commit made these regular errors while they had been
ParseErrors before.
* Return error message as string from modToPrintf
This is slightly simpler and they don't need to be errors.
* Skip setting includeDepth in generate
This sub parser isn't allowed to use $INCLUDE directives anyway.
Note: If generate is ever changed to allow $INCLUDE directives, then
this line must be added back. Without doing that, it would be
be possible to exceed maxIncludeDepth.
* Make generateReader errors sticky
ReadByte should not be called after an error has been returned, but
this is cheap insurance.
* Move file and lex fields to end of generateReader
These are only used for creating a ParseError and so are unlikely to be
accessed.
* Don't return offset with error in modToPrintf
Along for the ride, are some whitespace and style changes.
* Add whitespace to generate and simplify step
* Use a for loop instead of goto in generate
* Support $INCLUDE directives inside $GENERATE directives
This was previously supported and may be useful. This is now more
rigorous as the maximum include depth is respected and relative
$INCLUDE directives are now supported from within $GENERATE.
* Don't return any lexer tokens after read error
Without this, read errors are likely to be lost and become parse errors
of the remaining str. The $GENERATE code relies on surfacing errors from
the reader.
* Support $INCLUDE in NewRR and ReadRR
Removing $INCLUDE support from these is a breaking change and should
not be included in this pull request.
* Add test to ensure $GENERATE respects $INCLUDE support
* Unify TestZoneParserIncludeDisallowed with other tests
* Remove stray whitespace from TestGenerateSurfacesErrors
* Move ZoneParser SetX methods above Err method
* $GENERATE should not accept step of 0
If step is allowed to be 0, then generateReader (and the code it
replaced) will get stuck in an infinite loop.
This is a potential DOS vulnerability.
* Fix ReadRR comment for file argument
I missed this previosuly. The file argument is also used to
resolve relative $INCLUDE directives.
* Prevent test panics on nil error
* Rework ZoneParser.subNext
This is slightly cleaner and will close the underlying *os.File even
if an error occurs.
* Make ZoneParser.generate call subNext
This also moves the calls to setParseError into generate.
* Report errors when parsing rest of $GENERATE directive
* Report proper error location in $GENERATE directive
This makes error messages much clearer.
* Simplify modToPrintf func
Note: When width is 0, the leading 0 of the fmt string is now excluded.
This should not alter the formatting of numbers in anyway.
* Add comment explaining sub field
* Remove outdated error comment from generate
* Eliminate zlexer goroutine
This replaces the zlexer goroutine and channels with a zlexer struct
that maintains state and provides a channel-like API.
* Eliminate klexer goroutine
This replaces the klexer goroutine and channels with a klexer struct
that maintains state and provides a channel-like API.
* Merge scan into zlexer and klexer
This does result in tokenText existing twice, but it's pretty simple
and small so it's not that bad.
* Avoid using text/scanner.Position to track position
* Track escape within zlexer.Next
* Avoid zl.commt check on space and tab in zlexer
* Track stri within zlexer.Next
* Track comi within zlexer.Next
There is one special case at the start of a comment that needs to be
handled, otherwise this is as simple as stri was.
* Use a single token buffer in zlexer
This is safe as there is never both a non-empty string buffer and a
non-empty comment buffer.
* Don't hardcode length of zl.tok in zlexer
* Eliminate lex.length field
This is always set to len(l.token) and is only queried in a few places.
It was added in 47cc5b052d without any
obvious need.
* Add whitespace to klexer.Next
* Track lex within klexer.Next
* Use a strings.Builder in klexer.Next
* Simplify : case in klexer.Next
* Add whitespace to zlexer.Next
* Change for loop style in zlexer.Next and klexer.Next
* Surface read errors in zlexer
* Surface read errors from klexer
* Remove debug line from parseKey
* Rename tokenText to readByte
* Make readByte return ok bool
Also change the for loop style to match the Next for loops.
* Make readByte errors sticky
klexer.Next calls readByte separately from within the loop. Without
readByte being sticky, an error that occurs during that readByte call
may be lost.
* Panic in testRR if the error is non-nil
* Add whitespace and unify field setting in zlexer.Next
* Remove eof fields from zlexer and klexer
With readByte having sticky errors, this no longer needed. zl.eof = true
was also in the wrong place and could mask an unbalanced brace error.
* Merge zl.tok blocks in zlexer.Next
* Split the tok buffer into separate string and comment buffers
The invariant of stri > 0 && comi > 0 never being true was broken when
x == '\n' && !zl.quote && zl.commt && zl.brace != 0 (the
"If not in a brace this ends the comment AND the RR" block).
Split the buffer back out into two separate buffers to avoid clobbering.
* Replace token slices with arrays in zlexer
* Add a NewRR benchmark
* Move token buffers into zlexer.Next
These don't need to be retained across Next calls and can be stack
allocated inside Next. This drastically reduces memory consumption as
they accounted for nearly half of all the memory used.
name old alloc/op new alloc/op delta
NewRR-12 9.72kB ± 0% 4.98kB ± 0% -48.72% (p=0.000 n=10+10)
* Add a ReadRR benchmark
Unlike NewRR, this will use an io.Reader that does not implement any
methods aside from Read. In particular it does not implement
io.ByteReader.
* Avoid using a bufio.Reader for io.ByteReader readers
At the same time use a smaller buffer size of 1KiB rather than the
bufio.NewReader default of 4KiB.
name old time/op new time/op delta
NewRR-12 11.0µs ± 3% 9.5µs ± 2% -13.77% (p=0.000 n=9+10)
ReadRR-12 11.2µs ±16% 9.8µs ± 1% -13.03% (p=0.000 n=10+10)
name old alloc/op new alloc/op delta
NewRR-12 4.98kB ± 0% 0.81kB ± 0% -83.79% (p=0.000 n=10+10)
ReadRR-12 4.87kB ± 0% 1.82kB ± 0% -62.73% (p=0.000 n=10+10)
name old allocs/op new allocs/op delta
NewRR-12 19.0 ± 0% 17.0 ± 0% -10.53% (p=0.000 n=10+10)
ReadRR-12 19.0 ± 0% 19.0 ± 0% ~ (all equal)
ReadRR-12 11.2µs ±16% 9.8µs ± 1% -13.03% (p=0.000 n=10+10)
* Surface any remaining comment from zlexer.Next
* Improve comment handling in zlexer.Next
This both fixes a regression where comments could be lost under certain
circumstances and now emits comments that occur within braces.
* Remove outdated comment from zlexer.Next and klexer.Next
* Delay converting LF to space in braced comment
* Fixup TestParseZoneComments
* Remove tokenUpper field from lex
Not computing this for every token, and instead only
when needed is a substantial performance improvement.
name old time/op new time/op delta
NewRR-12 9.56µs ± 0% 6.30µs ± 1% -34.08% (p=0.000 n=9+10)
ReadRR-12 9.93µs ± 1% 6.67µs ± 1% -32.77% (p=0.000 n=10+10)
name old alloc/op new alloc/op delta
NewRR-12 824B ± 0% 808B ± 0% -1.94% (p=0.000 n=10+10)
ReadRR-12 1.83kB ± 0% 1.82kB ± 0% -0.87% (p=0.000 n=10+10)
name old allocs/op new allocs/op delta
NewRR-12 17.0 ± 0% 17.0 ± 0% ~ (all equal)
ReadRR-12 19.0 ± 0% 19.0 ± 0% ~ (all equal)
* Update ParseZone documentation to match comment changes
The zlexer code was changed to return comments more often, so update the
ParseZone documentation to match.
Although BIND9 documentations does not specify the possible size of offset
in $GENERATE clause, it clearly says that range must be a positive integer
between 0 and (2^31)-1. Moreover, BIND perfectly supports large offsets
which might be really handy when you're dealing with large intranets. I.e.
consider following case
```
$GENERATE 0-255 dhcp-${0,4,d} A 10.0.0.$
$GENERATE 0-255 dhcp-${256,4,d} A 10.0.1.$
$GENERATE 0-255 dhcp-${512,4,d} A 10.0.2.$
...
```
This change removes offset size check and introduces check that
0 >= (start + offset) and (end + offset) < (2^31)-1.
* Add a ParseZone test for $GENERATE.
* Add a test for modToPrintf used by $GENERATE.
* Correctly handle $GENERATE modifiers.
As per http://www.zytrax.com/books/dns/ch8/generate.html, the width and type (aka base)
components of a modifier are optional. This means that ${2,0,d}, ${2,0} and ${2} are
valid modifiers, however only the first format was previously permitted. Use default
values for the width and/or type if they are unspecified in the modifier.
* Make the error variable always named err.
Sometimes the error variable was named 'err' sometimes 'e'. Sometimes
'e' refered to an EDNS or string and not an error type.
* Use t.Errorf instead of t.Logf & t.Fail.
Remove the use of reflection when packing and unpacking, instead
generate all the pack and unpack functions using msg_generate.
This will generate zmsg.go which in turn calls the helper functions from
msg_helper.go.
This increases the speed by about ~30% while cutting back on memory
usage. Not all RRs are using it, but that will be rectified in upcoming
PR.
Most of the speed increase is in the header/question section parsing.
These functions *are* not generated, but straight forward enough. The
implementation can be found in msg.go.
The new code has been fuzzed by go-fuzz, which turned up some issues.
All files that started with 'z', and not autogenerated were renamed,
i.e. zscan.go is now scan.go.
Reflection is still used, in subsequent PRs it will be removed entirely.
Tom Thorogood
Michael Hudson-Doyle
chantra
Miek Gieben
Alexey Naidyonov
Joel Sing
Michael Haro