hare

commit e25547dd9ccda4ebda96d4d0370709580d1a1c35
parent 7814ccf5ac325814034b7e28df55e69af1ed3fc0
Author: Conrad Hoffmann <ch@bitfehler.net>
Date:   Tue, 11 Apr 2023 11:20:06 +0200

net::dns: add support for CAA records

Signed-off-by: Conrad Hoffmann <ch@bitfehler.net>

Diffstat:
M
net/dns/decode.ha
 | 
29
+++++++++++++++++++++++++++++
M
net/dns/types.ha
 | 
14
+++++++++++++-

2 files changed, 42 insertions(+), 1 deletion(-)
diff --git a/net/dns/decode.ha b/net/dns/decode.ha
@@ -193,6 +193,8 @@ fn decode_rdata(dec: *decoder, rtype: rtype, rlen: size) (rdata | format) = {
 		return decode_a(&sub);
 	case rtype::AAAA =>
 		return decode_aaaa(&sub);
+	case rtype::CAA =>
+		return decode_caa(&sub);
 	case rtype::CNAME =>
 		return decode_cname(&sub);
 	case rtype::MX =>
@@ -230,6 +232,33 @@ fn decode_aaaa(dec: *decoder) (rdata | format) = {
 	return ip: aaaa;
 };
 
+fn decode_caa(dec: *decoder) (rdata | format) = {
+	let flags = decode_u8(dec)?;
+	let tag_len = decode_u8(dec)?;
+
+	if (len(dec.cur) < tag_len) {
+		return format;
+	};
+	let tag = match(strings::fromutf8(dec.cur[..tag_len])) {
+	case let t: str =>
+		yield t;
+	case =>
+		return format;
+	};
+	let value = match (strings::fromutf8(dec.cur[tag_len..])) {
+	case let v: str =>
+		yield v;
+	case =>
+		return format;
+	};
+
+	return caa {
+		flags = flags,
+		tag = strings::dup(tag),
+		value = strings::dup(value),
+	};
+};
+
 fn decode_cname(dec: *decoder) (rdata | format) = {
 	return cname {
 		name = decode_name(dec)?,
diff --git a/net/dns/types.ha b/net/dns/types.ha
@@ -18,6 +18,7 @@ export type rtype = enum u16 {
 	AAAA = 28,
 	SRV = 33,
 	DNSKEY = 48,
+	CAA = 257,
 };
 
 // Question type (superset of [[rtype]]).
@@ -36,6 +37,7 @@ export type qtype = enum u16 {
 	AXFR = 252,
 	// *
 	ALL = 255,
+	CAA = 257,
 };
 
 // Class type (e.g. Internet).
@@ -133,6 +135,13 @@ export type a = ip::addr4;
 // An AAAA record.
 export type aaaa = ip::addr6;
 
+// A CAA record.
+export type caa = struct {
+	flags: u8,
+	tag: str,
+	value: str,
+};
+
 // A CNAME record.
 export type cname = struct {
 	name: []str,
@@ -174,7 +183,7 @@ export type txt = [][]u8;
 export type unknown_rdata = []u8;
 
 // Tagged union of supported rdata types.
-export type rdata = (a | aaaa | cname | mx | ns | soa | srv | txt | unknown_rdata);
+export type rdata = (a | aaaa | caa | cname | mx | ns | soa | srv | txt | unknown_rdata);
 
 // A DNS message, Hare representation. See [[encode]] and [[decode]] for the DNS
 // representation.
@@ -219,6 +228,9 @@ fn rrecord_finish(rr: *rrecord) void = {
 	match (rr.rdata) {
 	case let cn: cname =>
 		strings::freeall(cn.name);
+	case let ca: caa =>
+		free(ca.tag);
+		free(ca.value);
 	case let mx: mx =>
 		strings::freeall(mx.name);
 	case let ns: ns =>