From: Alan T. DeKok <aland@freeradius.org>
Date: Thu, 17 Mar 2022 22:55:36 +0000 (-0400)
Subject: allow "prefix=bits"
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=00910a1a8c33daf18533739b56c66ce02070e2f2;p=thirdparty%2Ffreeradius-server.git

allow "prefix=bits"

for prefixes which are encoded as 8 bits of prefix, followed by
0..3 bytes of actual content
---

diff --git a/src/protocols/dhcpv4/base.c b/src/protocols/dhcpv4/base.c
index ae5e52c3dd0..c899a62214e 100644
--- a/src/protocols/dhcpv4/base.c
+++ b/src/protocols/dhcpv4/base.c
@@ -747,6 +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("prefix=bits"),			FLAG_ENCODE_BITS_PREFIX },
 	{ L("encode=exists"),			FLAG_ENCODE_BOOL_EXISTS },
 };
 
@@ -764,7 +765,8 @@ static bool attr_valid(UNUSED fr_dict_t *dict, UNUSED fr_dict_attr_t const *pare
 			fr_strerror_const("string/octets arrays require the 'length=uint8' flag");
 			return false;
 		}
-	} else if (flags->array && !flags->length) {
+
+	} else if (flags->array && !flags->length && !flags->is_known_width) {
 		fr_strerror_const("Variable length attributes cannot be marked as 'array'");
 		return false;
 	}
@@ -780,8 +782,9 @@ static bool attr_valid(UNUSED fr_dict_t *dict, UNUSED fr_dict_attr_t const *pare
 		return false;
 	}
 
-	if ((type != FR_TYPE_IPV4_PREFIX) && (flags->subtype == FLAG_ENCODE_SPLIT_PREFIX)) {
-		fr_strerror_const("The 'split' flag can only be used with attributes of type 'ipv4prefix'");
+	if ((type != FR_TYPE_IPV4_PREFIX) &&
+	    ((flags->subtype == FLAG_ENCODE_SPLIT_PREFIX) || (flags->subtype == FLAG_ENCODE_BITS_PREFIX))) {
+		fr_strerror_const("The 'prefix=...' flag can only be used with attributes of type 'ipv4prefix'");
 		return false;
 	}
 
diff --git a/src/protocols/dhcpv4/dhcpv4.h b/src/protocols/dhcpv4/dhcpv4.h
index 31262f466f3..807953398db 100644
--- a/src/protocols/dhcpv4/dhcpv4.h
+++ b/src/protocols/dhcpv4/dhcpv4.h
@@ -72,11 +72,13 @@ 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_BITS_PREFIX,			//!< encode IPv4 prefixes as prefix bits, followed by IP.
 	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_bits_prefix(_da) (!(_da)->flags.extra && ((_da)->flags.subtype == FLAG_ENCODE_BITS_PREFIX))
 #define da_is_bool_exists(_da) (!(_da)->flags.extra && ((_da)->flags.subtype == FLAG_ENCODE_BOOL_EXISTS))
 
 typedef struct {