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suricata/rust/src/dns/parser.rs

816 lines
30 KiB
Rust

/* Copyright (C) 2017 Open Information Security Foundation
*
* You can copy, redistribute or modify this Program under the terms of
* the GNU General Public License version 2 as published by the Free
* Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* version 2 along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*/
//! Nom parsers for DNS.
use crate::dns::dns::*;
use nom7::combinator::{complete, rest};
use nom7::error::ErrorKind;
use nom7::multi::{count, length_data, many_m_n};
use nom7::number::streaming::{be_u16, be_u32, be_u8};
use nom7::{error_position, Err, IResult};
// Parse a DNS header.
pub fn dns_parse_header(i: &[u8]) -> IResult<&[u8], DNSHeader> {
let (i, tx_id) = be_u16(i)?;
let (i, flags) = be_u16(i)?;
let (i, questions) = be_u16(i)?;
let (i, answer_rr) = be_u16(i)?;
let (i, authority_rr) = be_u16(i)?;
let (i, additional_rr) = be_u16(i)?;
Ok((
i,
DNSHeader {
tx_id,
flags,
questions,
answer_rr,
authority_rr,
additional_rr,
},
))
}
/// Parse a DNS name.
///
/// Parameters:
/// start: the start of the name
/// message: the complete message that start is a part of
pub fn dns_parse_name<'a, 'b>(start: &'b [u8], message: &'b [u8]) -> IResult<&'b [u8], Vec<u8>> {
let mut pos = start;
let mut pivot = start;
let mut name: Vec<u8> = Vec::with_capacity(32);
let mut count = 0;
loop {
if pos.len() == 0 {
break;
}
let len = pos[0];
if len == 0x00 {
pos = &pos[1..];
break;
} else if len & 0b1100_0000 == 0 {
let (rem, label) = length_data(be_u8)(pos)?;
if name.len() > 0 {
name.push('.' as u8);
}
name.extend(label);
pos = rem;
} else if len & 0b1100_0000 == 0b1100_0000 {
let (rem, leader) = be_u16(pos)?;
let offset = usize::from(leader) & 0x3fff;
if offset > message.len() {
return Err(Err::Error(error_position!(pos, ErrorKind::OctDigit)));
}
pos = &message[offset..];
if pivot == start {
pivot = rem;
}
} else {
return Err(Err::Error(error_position!(pos, ErrorKind::OctDigit)));
}
// Return error if we've looped a certain number of times.
count += 1;
if count > 255 {
return Err(Err::Error(error_position!(pos, ErrorKind::OctDigit)));
}
}
// If we followed a pointer we return the position after the first
// pointer followed. Is there a better way to see if these slices
// diverged from each other? A straight up comparison would
// actually check the contents.
if pivot.len() != start.len() {
return Ok((pivot, name));
}
return Ok((pos, name));
}
/// Parse answer entries.
///
/// In keeping with the C implementation, answer values that can
/// contain multiple answers get expanded into their own answer
/// records. An example of this is a TXT record with multiple strings
/// in it - each string will be expanded to its own answer record.
///
/// This function could be a made a whole lot simpler if we logged a
/// multi-string TXT entry as a single quote string, similar to the
/// output of dig. Something to consider for a future version.
fn dns_parse_answer<'a>(
slice: &'a [u8], message: &'a [u8], count: usize,
) -> IResult<&'a [u8], Vec<DNSAnswerEntry>> {
let mut answers = Vec::new();
let mut input = slice;
fn subparser<'a>(
i: &'a [u8], message: &'a [u8],
) -> IResult<&'a [u8], (Vec<u8>, u16, u16, u32, &'a [u8])> {
let (i, name) = dns_parse_name(i, message)?;
let (i, rrtype) = be_u16(i)?;
let (i, rrclass) = be_u16(i)?;
let (i, ttl) = be_u32(i)?;
let (i, data) = length_data(be_u16)(i)?;
Ok((i, (name, rrtype, rrclass, ttl, data)))
}
for _ in 0..count {
match subparser(input, message) {
Ok((rem, val)) => {
let name = val.0;
let rrtype = val.1;
let rrclass = val.2;
let ttl = val.3;
let data = val.4;
let n = match rrtype {
DNS_RECORD_TYPE_TXT => {
// For TXT records we need to run the parser
// multiple times. Set n high, to the maximum
// value based on a max txt side of 65535, but
// taking into considering that strings need
// to be quoted, so half that.
32767
}
_ => {
// For all other types we only want to run the
// parser once, so set n to 1.
1
}
};
let result: IResult<&'a [u8], Vec<DNSRData>> =
many_m_n(1, n, complete(|b| dns_parse_rdata(b, message, rrtype)))(data);
match result {
Ok((_, rdatas)) => {
for rdata in rdatas {
answers.push(DNSAnswerEntry {
name: name.clone(),
rrtype,
rrclass,
ttl,
data: rdata,
});
}
}
Err(e) => {
return Err(e);
}
}
input = rem;
}
Err(e) => {
return Err(e);
}
}
}
return Ok((input, answers));
}
/// Parse a DNS response.
pub fn dns_parse_response<'a>(slice: &'a [u8]) -> IResult<&[u8], DNSResponse> {
let i = slice;
let (i, header) = dns_parse_header(i)?;
let (i, queries) = count(|b| dns_parse_query(b, slice), header.questions as usize)(i)?;
let (i, answers) = dns_parse_answer(i, slice, header.answer_rr as usize)?;
let (i, authorities) = dns_parse_answer(i, slice, header.authority_rr as usize)?;
Ok((
i,
DNSResponse {
header,
queries,
answers,
authorities,
},
))
}
/// Parse a single DNS query.
///
/// Arguments are suitable for using with call!:
///
/// call!(complete_dns_message_buffer)
pub fn dns_parse_query<'a>(input: &'a [u8], message: &'a [u8]) -> IResult<&'a [u8], DNSQueryEntry> {
let i = input;
let (i, name) = dns_parse_name(i, message)?;
let (i, rrtype) = be_u16(i)?;
let (i, rrclass) = be_u16(i)?;
Ok((
i,
DNSQueryEntry {
name,
rrtype,
rrclass,
},
))
}
fn dns_parse_rdata_a<'a>(input: &'a [u8]) -> IResult<&'a [u8], DNSRData> {
rest(input).map(|(input, data)| (input, DNSRData::A(data.to_vec())))
}
fn dns_parse_rdata_aaaa<'a>(input: &'a [u8]) -> IResult<&'a [u8], DNSRData> {
rest(input).map(|(input, data)| (input, DNSRData::AAAA(data.to_vec())))
}
fn dns_parse_rdata_cname<'a>(input: &'a [u8], message: &'a [u8]) -> IResult<&'a [u8], DNSRData> {
dns_parse_name(input, message).map(|(input, name)| (input, DNSRData::CNAME(name)))
}
fn dns_parse_rdata_ns<'a>(input: &'a [u8], message: &'a [u8]) -> IResult<&'a [u8], DNSRData> {
dns_parse_name(input, message).map(|(input, name)| (input, DNSRData::NS(name)))
}
fn dns_parse_rdata_ptr<'a>(input: &'a [u8], message: &'a [u8]) -> IResult<&'a [u8], DNSRData> {
dns_parse_name(input, message).map(|(input, name)| (input, DNSRData::PTR(name)))
}
fn dns_parse_rdata_soa<'a>(input: &'a [u8], message: &'a [u8]) -> IResult<&'a [u8], DNSRData> {
let i = input;
let (i, mname) = dns_parse_name(i, message)?;
let (i, rname) = dns_parse_name(i, message)?;
let (i, serial) = be_u32(i)?;
let (i, refresh) = be_u32(i)?;
let (i, retry) = be_u32(i)?;
let (i, expire) = be_u32(i)?;
let (i, minimum) = be_u32(i)?;
Ok((
i,
DNSRData::SOA(DNSRDataSOA {
mname,
rname,
serial,
refresh,
retry,
expire,
minimum,
}),
))
}
fn dns_parse_rdata_mx<'a>(input: &'a [u8], message: &'a [u8]) -> IResult<&'a [u8], DNSRData> {
// For MX we skip over the preference field before
// parsing out the name.
let (i, _) = be_u16(input)?;
let (i, name) = dns_parse_name(i, message)?;
Ok((i, DNSRData::MX(name)))
}
fn dns_parse_rdata_srv<'a>(input: &'a [u8], message: &'a [u8]) -> IResult<&'a [u8], DNSRData> {
let i = input;
let (i, priority) = be_u16(i)?;
let (i, weight) = be_u16(i)?;
let (i, port) = be_u16(i)?;
let (i, target) = dns_parse_name(i, message)?;
Ok((
i,
DNSRData::SRV(DNSRDataSRV {
priority,
weight,
port,
target,
}),
))
}
fn dns_parse_rdata_txt<'a>(input: &'a [u8]) -> IResult<&'a [u8], DNSRData> {
let (i, txt) = length_data(be_u8)(input)?;
Ok((i, DNSRData::TXT(txt.to_vec())))
}
fn dns_parse_rdata_null<'a>(input: &'a [u8]) -> IResult<&'a [u8], DNSRData> {
rest(input).map(|(input, data)| (input, DNSRData::NULL(data.to_vec())))
}
fn dns_parse_rdata_sshfp<'a>(input: &'a [u8]) -> IResult<&'a [u8], DNSRData> {
let i = input;
let (i, algo) = be_u8(i)?;
let (i, fp_type) = be_u8(i)?;
let fingerprint = i;
Ok((
&[],
DNSRData::SSHFP(DNSRDataSSHFP {
algo,
fp_type,
fingerprint: fingerprint.to_vec(),
}),
))
}
fn dns_parse_rdata_unknown<'a>(input: &'a [u8]) -> IResult<&'a [u8], DNSRData> {
rest(input).map(|(input, data)| (input, DNSRData::Unknown(data.to_vec())))
}
pub fn dns_parse_rdata<'a>(
input: &'a [u8], message: &'a [u8], rrtype: u16,
) -> IResult<&'a [u8], DNSRData> {
match rrtype {
DNS_RECORD_TYPE_A => dns_parse_rdata_a(input),
DNS_RECORD_TYPE_AAAA => dns_parse_rdata_aaaa(input),
DNS_RECORD_TYPE_CNAME => dns_parse_rdata_cname(input, message),
DNS_RECORD_TYPE_PTR => dns_parse_rdata_ptr(input, message),
DNS_RECORD_TYPE_SOA => dns_parse_rdata_soa(input, message),
DNS_RECORD_TYPE_MX => dns_parse_rdata_mx(input, message),
DNS_RECORD_TYPE_NS => dns_parse_rdata_ns(input, message),
DNS_RECORD_TYPE_TXT => dns_parse_rdata_txt(input),
DNS_RECORD_TYPE_NULL => dns_parse_rdata_null(input),
DNS_RECORD_TYPE_SSHFP => dns_parse_rdata_sshfp(input),
DNS_RECORD_TYPE_SRV => dns_parse_rdata_srv(input, message),
_ => dns_parse_rdata_unknown(input),
}
}
/// Parse a DNS request.
pub fn dns_parse_request<'a>(input: &'a [u8]) -> IResult<&[u8], DNSRequest> {
let i = input;
let (i, header) = dns_parse_header(i)?;
let (i, queries) = count(|b| dns_parse_query(b, input), header.questions as usize)(i)?;
Ok((i, DNSRequest { header, queries }))
}
#[cfg(test)]
mod tests {
use crate::dns::dns::{DNSHeader,DNSAnswerEntry};
use crate::dns::parser::*;
/// Parse a simple name with no pointers.
#[test]
fn test_dns_parse_name() {
let buf: &[u8] = &[
0x09, 0x63, /* .......c */
0x6c, 0x69, 0x65, 0x6e, 0x74, 0x2d, 0x63, 0x66, /* lient-cf */
0x07, 0x64, 0x72, 0x6f, 0x70, 0x62, 0x6f, 0x78, /* .dropbox */
0x03, 0x63, 0x6f, 0x6d, 0x00, 0x00, 0x01, 0x00, /* .com.... */
];
let expected_remainder: &[u8] = &[0x00, 0x01, 0x00];
let (remainder,name) = dns_parse_name(buf, buf).unwrap();
assert_eq!("client-cf.dropbox.com".as_bytes(), &name[..]);
assert_eq!(remainder, expected_remainder);
}
/// Test parsing a name with pointers.
#[test]
fn test_dns_parse_name_with_pointer() {
let buf: &[u8] = &[
0xd8, 0xcb, 0x8a, 0xed, 0xa1, 0x46, 0x00, 0x15 /* 0 - .....F.. */,
0x17, 0x0d, 0x06, 0xf7, 0x08, 0x00, 0x45, 0x00 /* 8 - ......E. */,
0x00, 0x7b, 0x71, 0x6e, 0x00, 0x00, 0x39, 0x11 /* 16 - .{qn..9. */,
0xf4, 0xd9, 0x08, 0x08, 0x08, 0x08, 0x0a, 0x10 /* 24 - ........ */,
0x01, 0x0b, 0x00, 0x35, 0xe1, 0x8e, 0x00, 0x67 /* 32 - ...5...g */,
0x60, 0x00, 0xef, 0x08, 0x81, 0x80, 0x00, 0x01 /* 40 - `....... */,
0x00, 0x03, 0x00, 0x00, 0x00, 0x01, 0x03, 0x77 /* 48 - .......w */,
0x77, 0x77, 0x0c, 0x73, 0x75, 0x72, 0x69, 0x63 /* 56 - ww.suric */,
0x61, 0x74, 0x61, 0x2d, 0x69, 0x64, 0x73, 0x03 /* 64 - ata-ids. */,
0x6f, 0x72, 0x67, 0x00, 0x00, 0x01, 0x00, 0x01 /* 72 - org..... */,
0xc0, 0x0c, 0x00, 0x05, 0x00, 0x01, 0x00, 0x00 /* 80 - ........ */,
0x0e, 0x0f, 0x00, 0x02, 0xc0, 0x10, 0xc0, 0x10 /* 88 - ........ */,
0x00, 0x01, 0x00, 0x01, 0x00, 0x00, 0x01, 0x2b /* 96 - .......+ */,
0x00, 0x04, 0xc0, 0x00, 0x4e, 0x19, 0xc0, 0x10 /* 104 - ....N... */,
0x00, 0x01, 0x00, 0x01, 0x00, 0x00, 0x01, 0x2b /* 112 - .......+ */,
0x00, 0x04, 0xc0, 0x00, 0x4e, 0x18, 0x00, 0x00 /* 120 - ....N... */,
0x29, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 /* 128 - )....... */,
0x00, /* 136 - . */
];
// The DNS payload starts at offset 42.
let message = &buf[42..];
// The name at offset 54 is the complete name.
let start1 = &buf[54..];
let res1 = dns_parse_name(start1, message);
assert_eq!(res1,
Ok((&start1[22..],
"www.suricata-ids.org".as_bytes().to_vec())));
// The second name starts at offset 80, but is just a pointer
// to the first.
let start2 = &buf[80..];
let res2 = dns_parse_name(start2, message);
assert_eq!(res2,
Ok((&start2[2..],
"www.suricata-ids.org".as_bytes().to_vec())));
// The third name starts at offset 94, but is a pointer to a
// portion of the first.
let start3 = &buf[94..];
let res3 = dns_parse_name(start3, message);
assert_eq!(res3,
Ok((&start3[2..],
"suricata-ids.org".as_bytes().to_vec())));
// The fourth name starts at offset 110, but is a pointer to a
// portion of the first.
let start4 = &buf[110..];
let res4 = dns_parse_name(start4, message);
assert_eq!(res4,
Ok((&start4[2..],
"suricata-ids.org".as_bytes().to_vec())));
}
#[test]
fn test_dns_parse_name_double_pointer() {
let buf: &[u8] = &[
0xd8, 0xcb, 0x8a, 0xed, 0xa1, 0x46, 0x00, 0x15 /* 0: .....F.. */,
0x17, 0x0d, 0x06, 0xf7, 0x08, 0x00, 0x45, 0x00 /* 8: ......E. */,
0x00, 0x66, 0x5e, 0x20, 0x40, 0x00, 0x40, 0x11 /* 16: .f^ @.@. */,
0xc6, 0x3b, 0x0a, 0x10, 0x01, 0x01, 0x0a, 0x10 /* 24: .;...... */,
0x01, 0x0b, 0x00, 0x35, 0xc2, 0x21, 0x00, 0x52 /* 32: ...5.!.R */,
0x35, 0xc5, 0x0d, 0x4f, 0x81, 0x80, 0x00, 0x01 /* 40: 5..O.... */,
0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x05, 0x62 /* 48: .......b */,
0x6c, 0x6f, 0x63, 0x6b, 0x07, 0x64, 0x72, 0x6f /* 56: lock.dro */,
0x70, 0x62, 0x6f, 0x78, 0x03, 0x63, 0x6f, 0x6d /* 64: pbox.com */,
0x00, 0x00, 0x01, 0x00, 0x01, 0xc0, 0x0c, 0x00 /* 72: ........ */,
0x05, 0x00, 0x01, 0x00, 0x00, 0x00, 0x09, 0x00 /* 80: ........ */,
0x0b, 0x05, 0x62, 0x6c, 0x6f, 0x63, 0x6b, 0x02 /* 88: ..block. */,
0x67, 0x31, 0xc0, 0x12, 0xc0, 0x2f, 0x00, 0x01 /* 96: g1.../.. */,
0x00, 0x01, 0x00, 0x00, 0x00, 0x08, 0x00, 0x04 /* 104: ........ */,
0x2d, 0x3a, 0x46, 0x21 /* 112: -:F! */
];
// The start of the DNS message in the above packet.
let message: &[u8] = &buf[42..];
// The start of the name we want to parse, 0xc0 0x2f, a
// pointer to offset 47 in the message (or 89 in the full
// packet).
let start: &[u8] = &buf[100..];
let res = dns_parse_name(start, message);
assert_eq!(res,
Ok((&start[2..],
"block.g1.dropbox.com".as_bytes().to_vec())));
}
#[test]
fn test_dns_parse_request() {
// DNS request from dig-a-www.suricata-ids.org.pcap.
let pkt: &[u8] = &[
0x8d, 0x32, 0x01, 0x20, 0x00, 0x01, /* ...2. .. */
0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x03, 0x77, /* .......w */
0x77, 0x77, 0x0c, 0x73, 0x75, 0x72, 0x69, 0x63, /* ww.suric */
0x61, 0x74, 0x61, 0x2d, 0x69, 0x64, 0x73, 0x03, /* ata-ids. */
0x6f, 0x72, 0x67, 0x00, 0x00, 0x01, 0x00, 0x01, /* org..... */
0x00, 0x00, 0x29, 0x10, 0x00, 0x00, 0x00, 0x00, /* ..)..... */
0x00, 0x00, 0x00 /* ... */
];
let res = dns_parse_request(pkt);
match res {
Ok((rem, request)) => {
// For now we have some remainder data as there is an
// additional record type we don't parse yet.
assert!(rem.len() > 0);
assert_eq!(request.header, DNSHeader {
tx_id: 0x8d32,
flags: 0x0120,
questions: 1,
answer_rr: 0,
authority_rr: 0,
additional_rr: 1,
});
assert_eq!(request.queries.len(), 1);
let query = &request.queries[0];
assert_eq!(query.name,
"www.suricata-ids.org".as_bytes().to_vec());
assert_eq!(query.rrtype, 1);
assert_eq!(query.rrclass, 1);
}
_ => {
assert!(false);
}
}
}
#[test]
fn test_dns_parse_response() {
// DNS response from dig-a-www.suricata-ids.org.pcap.
let pkt: &[u8] = &[
0x8d, 0x32, 0x81, 0xa0, 0x00, 0x01, /* ...2.... */
0x00, 0x03, 0x00, 0x00, 0x00, 0x00, 0x03, 0x77, /* .......w */
0x77, 0x77, 0x0c, 0x73, 0x75, 0x72, 0x69, 0x63, /* ww.suric */
0x61, 0x74, 0x61, 0x2d, 0x69, 0x64, 0x73, 0x03, /* ata-ids. */
0x6f, 0x72, 0x67, 0x00, 0x00, 0x01, 0x00, 0x01, /* org..... */
0xc0, 0x0c, 0x00, 0x05, 0x00, 0x01, 0x00, 0x00, /* ........ */
0x0d, 0xd8, 0x00, 0x12, 0x0c, 0x73, 0x75, 0x72, /* .....sur */
0x69, 0x63, 0x61, 0x74, 0x61, 0x2d, 0x69, 0x64, /* icata-id */
0x73, 0x03, 0x6f, 0x72, 0x67, 0x00, 0xc0, 0x32, /* s.org..2 */
0x00, 0x01, 0x00, 0x01, 0x00, 0x00, 0x00, 0xf4, /* ........ */
0x00, 0x04, 0xc0, 0x00, 0x4e, 0x18, 0xc0, 0x32, /* ....N..2 */
0x00, 0x01, 0x00, 0x01, 0x00, 0x00, 0x00, 0xf4, /* ........ */
0x00, 0x04, 0xc0, 0x00, 0x4e, 0x19 /* ....N. */
];
let res = dns_parse_response(pkt);
match res {
Ok((rem, response)) => {
// The response should be full parsed.
assert_eq!(rem.len(), 0);
assert_eq!(response.header, DNSHeader{
tx_id: 0x8d32,
flags: 0x81a0,
questions: 1,
answer_rr: 3,
authority_rr: 0,
additional_rr: 0,
});
assert_eq!(response.answers.len(), 3);
let answer1 = &response.answers[0];
assert_eq!(answer1.name,
"www.suricata-ids.org".as_bytes().to_vec());
assert_eq!(answer1.rrtype, 5);
assert_eq!(answer1.rrclass, 1);
assert_eq!(answer1.ttl, 3544);
assert_eq!(answer1.data,
DNSRData::CNAME("suricata-ids.org".as_bytes().to_vec()));
let answer2 = &response.answers[1];
assert_eq!(answer2, &DNSAnswerEntry{
name: "suricata-ids.org".as_bytes().to_vec(),
rrtype: 1,
rrclass: 1,
ttl: 244,
data: DNSRData::A([192, 0, 78, 24].to_vec()),
});
let answer3 = &response.answers[2];
assert_eq!(answer3, &DNSAnswerEntry{
name: "suricata-ids.org".as_bytes().to_vec(),
rrtype: 1,
rrclass: 1,
ttl: 244,
data: DNSRData::A([192, 0, 78, 25].to_vec()),
})
},
_ => {
assert!(false);
}
}
}
#[test]
fn test_dns_parse_response_nxdomain_soa() {
// DNS response with an SOA authority record from
// dns-udp-nxdomain-soa.pcap.
let pkt: &[u8] = &[
0x82, 0x95, 0x81, 0x83, 0x00, 0x01, /* j....... */
0x00, 0x00, 0x00, 0x01, 0x00, 0x01, 0x03, 0x64, /* .......d */
0x6e, 0x65, 0x04, 0x6f, 0x69, 0x73, 0x66, 0x03, /* ne.oisf. */
0x6e, 0x65, 0x74, 0x00, 0x00, 0x01, 0x00, 0x01, /* net..... */
0xc0, 0x10, 0x00, 0x06, 0x00, 0x01, 0x00, 0x00, /* ........ */
0x03, 0x83, 0x00, 0x45, 0x06, 0x6e, 0x73, 0x2d, /* ...E.ns- */
0x31, 0x31, 0x30, 0x09, 0x61, 0x77, 0x73, 0x64, /* 110.awsd */
0x6e, 0x73, 0x2d, 0x31, 0x33, 0x03, 0x63, 0x6f, /* ns-13.co */
0x6d, 0x00, 0x11, 0x61, 0x77, 0x73, 0x64, 0x6e, /* m..awsdn */
0x73, 0x2d, 0x68, 0x6f, 0x73, 0x74, 0x6d, 0x61, /* s-hostma */
0x73, 0x74, 0x65, 0x72, 0x06, 0x61, 0x6d, 0x61, /* ster.ama */
0x7a, 0x6f, 0x6e, 0xc0, 0x3b, 0x00, 0x00, 0x00, /* zon.;... */
0x01, 0x00, 0x00, 0x1c, 0x20, 0x00, 0x00, 0x03, /* .... ... */
0x84, 0x00, 0x12, 0x75, 0x00, 0x00, 0x01, 0x51, /* ...u...Q */
0x80, 0x00, 0x00, 0x29, 0x02, 0x00, 0x00, 0x00, /* ...).... */
0x00, 0x00, 0x00, 0x00 /* .... */
];
let res = dns_parse_response(pkt);
match res {
Ok((rem, response)) => {
// For now we have some remainder data as there is an
// additional record type we don't parse yet.
assert!(rem.len() > 0);
assert_eq!(response.header, DNSHeader{
tx_id: 0x8295,
flags: 0x8183,
questions: 1,
answer_rr: 0,
authority_rr: 1,
additional_rr: 1,
});
assert_eq!(response.authorities.len(), 1);
let authority = &response.authorities[0];
assert_eq!(authority.name,
"oisf.net".as_bytes().to_vec());
assert_eq!(authority.rrtype, 6);
assert_eq!(authority.rrclass, 1);
assert_eq!(authority.ttl, 899);
assert_eq!(authority.data,
DNSRData::SOA(DNSRDataSOA{
mname: "ns-110.awsdns-13.com".as_bytes().to_vec(),
rname: "awsdns-hostmaster.amazon.com".as_bytes().to_vec(),
serial: 1,
refresh: 7200,
retry: 900,
expire: 1209600,
minimum: 86400,
}));
},
_ => {
assert!(false);
}
}
}
#[test]
fn test_dns_parse_response_null() {
// DNS response with a NULL record from
// https://redmine.openinfosecfoundation.org/attachments/2062
let pkt: &[u8] = &[
0x12, 0xb0, 0x84, 0x00, 0x00, 0x01, 0x00, 0x01, /* ........ */
0x00, 0x00, 0x00, 0x00, 0x0b, 0x76, 0x61, 0x61, /* .....vaa */
0x61, 0x61, 0x6b, 0x61, 0x72, 0x64, 0x6c, 0x69, /* aakardli */
0x06, 0x70, 0x69, 0x72, 0x61, 0x74, 0x65, 0x03, /* .pirate. */
0x73, 0x65, 0x61, 0x00, 0x00, 0x0a, 0x00, 0x01, /* sea..... */
0xc0, 0x0c, 0x00, 0x0a, 0x00, 0x01, 0x00, 0x00, /* ........ */
0x00, 0x00, 0x00, 0x09, 0x56, 0x41, 0x43, 0x4b, /* ....VACK */
0x44, 0x03, 0xc5, 0xe9, 0x01, /* D.... */
];
let res = dns_parse_response(pkt);
match res {
Ok((rem, response)) => {
// The response should be fully parsed.
assert_eq!(rem.len(), 0);
assert_eq!(response.header, DNSHeader {
tx_id: 0x12b0,
flags: 0x8400,
questions: 1,
answer_rr: 1,
authority_rr: 0,
additional_rr: 0,
});
assert_eq!(response.queries.len(), 1);
let query = &response.queries[0];
assert_eq!(query.name,
"vaaaakardli.pirate.sea".as_bytes().to_vec());
assert_eq!(query.rrtype, DNS_RECORD_TYPE_NULL);
assert_eq!(query.rrclass, 1);
assert_eq!(response.answers.len(), 1);
let answer = &response.answers[0];
assert_eq!(answer.name,
"vaaaakardli.pirate.sea".as_bytes().to_vec());
assert_eq!(answer.rrtype, DNS_RECORD_TYPE_NULL);
assert_eq!(answer.rrclass, 1);
assert_eq!(answer.ttl, 0);
assert_eq!(answer.data, DNSRData::NULL(vec![
0x56, 0x41, 0x43, 0x4b, /* VACK */
0x44, 0x03, 0xc5, 0xe9, 0x01, /* D.... */
]));
},
_ => {
assert!(false);
}
}
}
#[test]
fn test_dns_parse_rdata_sshfp() {
// Dummy data since we don't have a pcap sample.
let data: &[u8] = &[
// algo: DSS
0x02,
// fp_type: SHA-1
0x01,
// fingerprint: 123456789abcdef67890123456789abcdef67890
0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc, 0xde, 0xf6, 0x78, 0x90,
0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc, 0xde, 0xf6, 0x78, 0x90
];
let res = dns_parse_rdata_sshfp(data);
match res {
Ok((rem, rdata)) => {
// The data should be fully parsed.
assert_eq!(rem.len(), 0);
match rdata {
DNSRData::SSHFP(sshfp) => {
assert_eq!(sshfp.algo, 2);
assert_eq!(sshfp.fp_type, 1);
assert_eq!(sshfp.fingerprint, &data[2..]);
},
_ => {
assert!(false);
}
}
},
_ => {
assert!(false);
}
}
}
#[test]
fn test_dns_parse_rdata_srv() {
/* ; <<>> DiG 9.11.5-P4-5.1+deb10u2-Debian <<>> _sip._udp.sip.voice.google.com SRV
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 1524
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 3
[...]
;; ANSWER SECTION:
_sip._udp.sip.voice.google.com. 300 IN SRV 10 1 5060 sip-anycast-1.voice.google.com.
_sip._udp.sip.voice.google.com. 300 IN SRV 20 1 5060 sip-anycast-2.voice.google.com.
[...]
;; Query time: 72 msec
;; MSG SIZE rcvd: 191 */
let pkt: &[u8] = &[
0xeb, 0x56, 0x81, 0x80, 0x00, 0x01, 0x00, 0x02, 0x00, 0x00,
0x00, 0x01, 0x04, 0x5f, 0x73, 0x69, 0x70, 0x04, 0x5f, 0x75,
0x64, 0x70, 0x03, 0x73, 0x69, 0x70, 0x05, 0x76, 0x6f, 0x69,
0x63, 0x65, 0x06, 0x67, 0x6f, 0x6f, 0x67, 0x6c, 0x65, 0x03,
0x63, 0x6f, 0x6d, 0x00, 0x00, 0x21, 0x00, 0x01, 0xc0, 0x0c,
0x00, 0x21, 0x00, 0x01, 0x00, 0x00, 0x01, 0x13, 0x00, 0x26,
0x00, 0x14, 0x00, 0x01, 0x13, 0xc4, 0x0d, 0x73, 0x69, 0x70,
0x2d, 0x61, 0x6e, 0x79, 0x63, 0x61, 0x73, 0x74, 0x2d, 0x32,
0x05, 0x76, 0x6f, 0x69, 0x63, 0x65, 0x06, 0x67, 0x6f, 0x6f,
0x67, 0x6c, 0x65, 0x03, 0x63, 0x6f, 0x6d, 0x00, 0xc0, 0x0c,
0x00, 0x21, 0x00, 0x01, 0x00, 0x00, 0x01, 0x13, 0x00, 0x26,
0x00, 0x0a, 0x00, 0x01, 0x13, 0xc4, 0x0d, 0x73, 0x69, 0x70,
0x2d, 0x61, 0x6e, 0x79, 0x63, 0x61, 0x73, 0x74, 0x2d, 0x31,
0x05, 0x76, 0x6f, 0x69, 0x63, 0x65, 0x06, 0x67, 0x6f, 0x6f,
0x67, 0x6c, 0x65, 0x03, 0x63, 0x6f, 0x6d, 0x00
];
let res = dns_parse_response(pkt);
match res {
Ok((rem, response)) => {
// The data should be fully parsed.
assert_eq!(rem.len(), 0);
assert_eq!(response.answers.len(), 2);
let answer1 = &response.answers[0];
match &answer1.data {
DNSRData::SRV(srv) => {
assert_eq!(srv.priority, 20);
assert_eq!(srv.weight, 1);
assert_eq!(srv.port, 5060);
assert_eq!(srv.target,
"sip-anycast-2.voice.google.com".as_bytes().to_vec());
}
_ => {
assert!(false);
}
}
let answer2 = &response.answers[1];
match &answer2.data {
DNSRData::SRV(srv) => {
assert_eq!(srv.priority, 10);
assert_eq!(srv.weight, 1);
assert_eq!(srv.port, 5060);
assert_eq!(srv.target,
"sip-anycast-1.voice.google.com".as_bytes().to_vec());
}
_ => {
assert!(false);
}
}
},
_ => {
assert!(false);
}
}
}
}