hare

commit 07fb96f9ad9c586ec5500929bf4a9967ca1a1107
parent 6f88e34bdcc1db8c1b92b575f10a2069542aa6f3
Author: Drew DeVault <sir@cmpwn.com>
Date:   Tue, 29 Jun 2021 13:34:40 -0400

net::dns: implement TXT rdata decoder

Signed-off-by: Drew DeVault <sir@cmpwn.com>

Diffstat:
M
net/dns/decode.ha
 | 
25
+++++++++++++++++++++++++
M
net/dns/types.ha
 | 
13
++++++++++++-

2 files changed, 37 insertions(+), 1 deletion(-)
diff --git a/net/dns/decode.ha b/net/dns/decode.ha
@@ -41,6 +41,15 @@ fn decoder_init(buf: []u8) decoder = decoder {
 	...
 };
 
+fn decode_u8(dec: *decoder) (u8 | format) = {
+	if (len(dec.cur) < 1) {
+		return format;
+	};
+	const val = dec.cur[0];
+	dec.cur = dec.cur[1..];
+	return val;
+};
+
 fn decode_u16(dec: *decoder) (u16 | format) = {
 	if (len(dec.cur) < 2) {
 		return format;
@@ -140,6 +149,7 @@ fn decode_rdata(dec: *decoder, rtype: rtype, rlen: size) (rdata | format) = {
 		rtype::A => decode_a(dec),
 		rtype::AAAA => decode_aaaa(dec),
 		rtype::MX => decode_mx(dec),
+		rtype::TXT => decode_txt(dec),
 		* => {
 			let buf = dec.cur[..rlen];
 			dec.cur = dec.cur[rlen..];
@@ -175,4 +185,19 @@ fn decode_mx(dec: *decoder) (rdata | format) = {
 	};
 };
 
+fn decode_txt(dec: *decoder) (rdata | format) = {
+	let items: txt = [];
+	for (len(dec.cur) != 0) {
+		const ln = decode_u8(dec)?;
+		if (len(dec.cur) < ln) {
+			return format;
+		};
+		let item: []u8 = [];
+		append(item, dec.cur[..ln]...);
+		dec.cur = dec.cur[ln..];
+		append(items, item);
+	};
+	return items;
+};
+
 // TODO: Expand breadth of supported rdata decoders
diff --git a/net/dns/types.ha b/net/dns/types.ha
@@ -133,11 +133,14 @@ export type mx = struct {
 	name: []str,
 };
 
+// A TXT record.
+export type txt = [][]u8;
+
 // The raw rdata field for an [[rrecord]] with an unknown [[rtype]].
 export type unknown_rdata = []u8;
 
 // Tagged union of supported rdata types.
-export type rdata = (a | aaaa | mx | unknown_rdata);
+export type rdata = (a | aaaa | mx | txt | unknown_rdata);
 
 // A DNS message, Hare representation. See [[encode]] and [[decode]] for the DNS
 // representation.
@@ -181,10 +184,18 @@ fn strings_free(in: []str) void = {
 	free(in);
 };
 
+fn bytes_free(in: [][]u8) void = {
+	for (let i = 0z; i < len(in); i += 1) {
+		free(in[i]);
+	};
+	free(in);
+};
+
 fn rrecord_finish(rr: *rrecord) void = {
 	strings_free(rr.name);
 	match (rr.rdata) {
 		mx: mx => strings_free(mx.name),
+		tx: txt => bytes_free(tx: [][]u8),
 		* => void,
 	};
 };