handle options with no data. Helps with #2601

and add test cases

diff --git a/src/protocols/dhcpv4/decode.c b/src/protocols/dhcpv4/decode.c
index 4bacbe3e37a1244a528bf8a963a8f39400518672..6c12472ea925263bccd71b2084983e1423008983 100644 (file)
--- a/src/protocols/dhcpv4/decode.c
+++ b/src/protocols/dhcpv4/decode.c
@@ -292,7 +292,7 @@ static ssize_t decode_tlv(TALLOC_CTX *ctx, fr_cursor_t *cursor, fr_dict_attr_t c
                               fr_int2str(fr_value_box_type_table, child->type, "<invalid>"), child->name);
 
                tlv_len = decode_value(ctx, cursor, child, p + 2, p[1]);
-               if (tlv_len <= 0) {
+               if (tlv_len < 0) {
                        fr_dict_unknown_free(&child);
                        return tlv_len;
                }

diff --git a/src/tests/unit/dhcpv4.txt b/src/tests/unit/dhcpv4.txt
index 01039a482d8cd3ec83d6515c28967d2e76ea853a..447b039fa317b5b0b93f4b2d2b1c828051f698d4 100644 (file)
--- a/src/tests/unit/dhcpv4.txt
+++ b/src/tests/unit/dhcpv4.txt
@@ -47,6 +47,12 @@ data 52 e3 01 e1 6f 68 20 68 61 69 20 74 68 69 73 20 69 73 20 61 6e 20 61 67 65
 encode-pair DHCP-Rapid-Commit = ''
 data 50 00
 
+#
+#  Decoding empty options yields empty data
+#
+decode-pair -
+data DHCP-Rapid-Commit = 0x
+
 # 255 bytes are OK
 encode-pair DHCP-Domain-Name = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
 data 0f ff 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78
@@ -57,3 +63,13 @@ data 0e ff 31 32 33 34 35 36 37 38 39 30 31 32 33 34 35 36 37 38 39 30 31 32 33
 # A very long option should be split automatically
 encode-pair DHCP-Domain-Name = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
 data 0f ff 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 0f 2d 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78 78
+
+
+#
+#  3 isn't used for anything, and should just be treated as an unknown attribute
+#
+decode-pair 52 07 01 03 ab cd ef 03 00
+data DHCP-Relay-Circuit-Id = 0xabcdef, Attr-82.3 = 0x
+
+decode-pair 52 07 01 03 ab cd ef 03 01 ad
+data DHCP-Relay-Circuit-Id = 0xabcdef, Attr-82.3 = 0xad