From: Alan T. DeKok <aland@freeradius.org>
Date: Thu, 17 Mar 2022 15:30:55 +0000 (-0400)
Subject: allow for Rapid-Commit to be special
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=31fa68c3ac2d3c1e394b711276a6fd427066ee7c;p=thirdparty%2Ffreeradius-server.git

allow for Rapid-Commit to be special

normal bools are encoded as 1 byte of 0/1
Rapid-Commit is stupid, and gets stupid encoding.
---

diff --git a/share/dictionary/dhcpv4/dictionary.rfc2131 b/share/dictionary/dhcpv4/dictionary.rfc2131
index f2d418782e8..450bdfd1991 100644
--- a/share/dictionary/dhcpv4/dictionary.rfc2131
+++ b/share/dictionary/dhcpv4/dictionary.rfc2131
@@ -141,7 +141,7 @@ ATTRIBUTE	STDA-Server-Address			76	ipaddr array
 ATTRIBUTE	User-Class				77	octets
 
 # Rapid Commit
-ATTRIBUTE	Rapid-Commit				80	bool
+ATTRIBUTE	Rapid-Commit				80	bool		encode=exists
 # Fully Qualified Domain Name
 ATTRIBUTE	Client-FQDN				81	string
 # Relay Agent Information
diff --git a/src/protocols/dhcpv4/base.c b/src/protocols/dhcpv4/base.c
index e9c9437e437..ae5e52c3dd0 100644
--- a/src/protocols/dhcpv4/base.c
+++ b/src/protocols/dhcpv4/base.c
@@ -371,7 +371,8 @@ void *fr_dhcpv4_next_encodable(fr_dlist_head_t *list, void *to_eval, void *uctx)
 	for (c = to_eval; c; c = fr_dlist_next(list, c)) {
 		PAIR_VERIFY(c);
 		if (c->da->dict != dict || c->da->flags.internal) continue;
-		if (c->da->type == FR_TYPE_BOOL && !c->vp_bool) continue;
+
+		if (c->da->type == FR_TYPE_BOOL && da_is_bool_exists(c->da) && !c->vp_bool) continue;
 
 		break;
 	}
@@ -746,6 +747,7 @@ static fr_table_num_ordered_t const subtype_table[] = {
 	{ L("dns_label"),			FLAG_ENCODE_DNS_LABEL },
 	{ L("encode=dns_label"),		FLAG_ENCODE_DNS_LABEL },
 	{ L("prefix=split"),			FLAG_ENCODE_SPLIT_PREFIX },
+	{ L("encode=exists"),			FLAG_ENCODE_BOOL_EXISTS },
 };
 
 static bool attr_valid(UNUSED fr_dict_t *dict, UNUSED fr_dict_attr_t const *parent,
@@ -783,6 +785,11 @@ static bool attr_valid(UNUSED fr_dict_t *dict, UNUSED fr_dict_attr_t const *pare
 		return false;
 	}
 
+	if ((type != FR_TYPE_BOOL) && (flags->subtype == FLAG_ENCODE_BOOL_EXISTS)) {
+		fr_strerror_const("The 'encode=exists' flag can only be used with attributes of type 'bool'");
+		return false;
+	}
+
 	return true;
 }
 
diff --git a/src/protocols/dhcpv4/dhcpv4.h b/src/protocols/dhcpv4/dhcpv4.h
index bf8445fa42c..31262f466f3 100644
--- a/src/protocols/dhcpv4/dhcpv4.h
+++ b/src/protocols/dhcpv4/dhcpv4.h
@@ -72,10 +72,12 @@ enum {
 	FLAG_ENCODE_NONE = 0,				//!< no particular encoding for DHCPv6 strings
 	FLAG_ENCODE_DNS_LABEL,				//!< encode as DNS label
 	FLAG_ENCODE_SPLIT_PREFIX,			//!< encode IPv4 prefixes as Policy-Filter, split into IP/mask
+	FLAG_ENCODE_BOOL_EXISTS,			//!< bool as existence checks
 };
 
 #define da_is_dns_label(_da) (!(_da)->flags.extra && ((_da)->flags.subtype == FLAG_ENCODE_DNS_LABEL))
 #define da_is_split_prefix(_da) (!(_da)->flags.extra && ((_da)->flags.subtype == FLAG_ENCODE_SPLIT_PREFIX))
+#define da_is_bool_exists(_da) (!(_da)->flags.extra && ((_da)->flags.subtype == FLAG_ENCODE_BOOL_EXISTS))
 
 typedef struct {
 	uint8_t		opcode;
diff --git a/src/protocols/dhcpv4/encode.c b/src/protocols/dhcpv4/encode.c
index 45bb7bb541f..58758e5a035 100644
--- a/src/protocols/dhcpv4/encode.c
+++ b/src/protocols/dhcpv4/encode.c
@@ -125,6 +125,10 @@ static ssize_t encode_value(fr_dbuff_t *dbuff,
 		 *	Rapid-Commit does this.  Options 19/20 require encoding as one byte of 0/1.
 		 */
 	case FR_TYPE_BOOL:
+		if (da_is_bool_exists(vp->da)) {
+			break;
+		}
+		fr_dbuff_in(&work_dbuff, (uint8_t) (vp->vp_bool == true));
 		break;
 
 	case FR_TYPE_IPV4_PREFIX:
diff --git a/src/tests/unit/protocols/dhcpv4/base.txt b/src/tests/unit/protocols/dhcpv4/base.txt
index a093d642425..eedfaee231c 100644
--- a/src/tests/unit/protocols/dhcpv4/base.txt
+++ b/src/tests/unit/protocols/dhcpv4/base.txt
@@ -5,18 +5,6 @@ proto dhcpv4
 proto-dictionary dhcpv4
 fuzzer-out dhcpv4
 
-#
-#  bools which are false don't get encoded
-#
-encode-pair IP-Forward-Enable = false
-match 
-
-encode-pair IP-Forward-Enable = true
-match 13 00
-
-decode-pair -
-match IP-Forward-Enable = yes
-
 #
 #  DHCP TLV types
 #
@@ -117,4 +105,4 @@ decode-pair -
 match Relay-Agent-Information.Circuit-Id = 0x3132333435363738396131323334353637383962313233343536373839633132333435363738396431323334353637383965313233343536373839663132333435363738396731323334353637383968313233343536373839613132333435363738396131323334353637383961313233343536373839613132333435363738396131323334353637383961313233343536373839613132333435363738396131323334353637383961313233343536373839613132333435363738396131323334353637383961313233343536373839613132333435363738396131323334353637383961313233343536373839613132333435363738396178797a
 
 count
-match 51
+match 45
diff --git a/src/tests/unit/protocols/dhcpv4/bools.txt b/src/tests/unit/protocols/dhcpv4/bools.txt
new file mode 100644
index 00000000000..b317099c4a2
--- /dev/null
+++ b/src/tests/unit/protocols/dhcpv4/bools.txt
@@ -0,0 +1,64 @@
+#
+#  Test vectors for bools, which are shit and random.
+#
+proto dhcpv4
+proto-dictionary dhcpv4
+fuzzer-out dhcpv4
+
+encode-pair Rapid-Commit = yes
+match 50 00
+
+decode-pair -
+match Rapid-Commit = yes
+
+#
+#  false is "don't encode"
+#
+encode-pair Rapid-Commit = false
+match 
+
+#
+#  Normal bools get encoded as 0/1
+#
+encode-pair IP-Forward-Enable = false
+match 13 01 00
+
+encode-pair IP-Forward-Enable = true
+match 13 01 01
+
+decode-pair -
+match IP-Forward-Enable = yes
+
+#
+#  All non-zero values are "true"
+#
+decode-pair 13 01 88
+match IP-Forward-Enable = yes
+
+#
+#  Rapid-Commit is stupid
+#
+encode-pair Rapid-Commit = yes
+match 50 00
+
+decode-pair -
+match Rapid-Commit = yes
+
+#
+#  false is "don't encode"
+#
+encode-pair Rapid-Commit = false
+match 
+
+#
+#  We allow Rapid-Commit to be normal, if it so chooses
+#
+decode-pair 50 01 00
+match Rapid-Commit = no
+
+decode-pair 50 01 01
+match Rapid-Commit = yes
+
+
+count
+match 27