Merge pull request #30028 from yuwata/duid-fix-size

dhcp: fix DUID size

Author: bluca

src/libsystemd-network/dhcp-identifier.h

@@ -22,11 +22,12 @@ typedef enum DUIDType {
         _DUID_TYPE_FORCE_U16 = UINT16_MAX,
 } DUIDType;
 
-/* RFC 3315 section 9.1:
- *      A DUID can be no more than 128 octets long (not including the type code).
- */
-#define MAX_DUID_LEN 128
-#define MAX_DUID_DATA_LEN (MAX_DUID_LEN - sizeof(be16_t))
+/* RFC 8415 section 11.1:
+ * A DUID consists of a 2-octet type code represented in network byte order, followed by a variable number of
+ * octets that make up the actual identifier. The length of the DUID (not including the type code) is at
+ * least 1 octet and at most 128 octets. */
+#define MAX_DUID_DATA_LEN 128
+#define MAX_DUID_LEN (sizeof(be16_t) + MAX_DUID_DATA_LEN)
 
 /* https://tools.ietf.org/html/rfc3315#section-9.1 */
 struct duid {
@@ -58,7 +59,6 @@ struct duid {
         };
 } _packed_;
 
-int dhcp_validate_duid_len(DUIDType duid_type, size_t duid_len, bool strict);
 int dhcp_identifier_set_duid_llt(
                 const struct hw_addr_data *hw_addr,
                 uint16_t arp_type,

src/libsystemd-network/sd-dhcp6-client.c

@@ -276,7 +276,7 @@ int sd_dhcp6_client_duid_as_string(
         int r;
 
         assert_return(client, -EINVAL);
-        assert_return(client->duid_len > 0, -ENODATA);
+        assert_return(client->duid_len > offsetof(struct duid, raw.data), -ENODATA);
         assert_return(duid, -EINVAL);
 
         v = duid_type_to_string(be16toh(client->duid.type));
@@ -290,7 +290,7 @@ int sd_dhcp6_client_duid_as_string(
                         return -ENOMEM;
         }
 
-        t = hexmem(&client->duid.raw.data, client->duid_len);
+        t = hexmem(client->duid.raw.data, client->duid_len - offsetof(struct duid, raw.data));
         if (!t)
                 return -ENOMEM;
 

src/network/test-networkd-conf.c

@@ -83,25 +83,35 @@ static void test_config_parse_ether_addrs_one(const char *rvalue, const struct e
         assert_se(set_size(s) == 0);
 }
 
-#define BYTES_0_126 \
+#define STR_OK                                                          \
         "00:01:02:03:04:05:06:07:08:09:0a:0b:0c:0d:0e:0f:"              \
         "10:11:12:13:14:15:16:17:18:19:1a:1b:1c:1d:1e:1f:"              \
         "20:21:22:23:24:25:26:27:28:29:2a:2b:2c:2d:2e:2f:"              \
         "30:31:32:33:34:35:36:37:38:39:3a:3b:3c:3d:3e:3f:"              \
         "40:41:42:43:44:45:46:47:48:49:4a:4b:4c:4d:4e:4f:"              \
         "50:51:52:53:54:55:56:57:58:59:5a:5b:5c:5d:5e:5f:"              \
         "60:61:62:63:64:65:66:67:68:69:6a:6b:6c:6d:6e:6f:"              \
-        "70:71:72:73:74:75:76:77:78:79:7a:7b:7c:7d:7e"
+        "70:71:72:73:74:75:76:77:78:79:7a:7b:7c:7d:7e:7f"
+#define STR_TOO_LONG                                                    \
+        "00:01:02:03:04:05:06:07:08:09:0a:0b:0c:0d:0e:0f:"              \
+        "10:11:12:13:14:15:16:17:18:19:1a:1b:1c:1d:1e:1f:"              \
+        "20:21:22:23:24:25:26:27:28:29:2a:2b:2c:2d:2e:2f:"              \
+        "30:31:32:33:34:35:36:37:38:39:3a:3b:3c:3d:3e:3f:"              \
+        "40:41:42:43:44:45:46:47:48:49:4a:4b:4c:4d:4e:4f:"              \
+        "50:51:52:53:54:55:56:57:58:59:5a:5b:5c:5d:5e:5f:"              \
+        "60:61:62:63:64:65:66:67:68:69:6a:6b:6c:6d:6e:6f:"              \
+        "70:71:72:73:74:75:76:77:78:79:7a:7b:7c:7d:7e:7f:"              \
+        "80"
 
-#define BYTES_1_126 {                                                                    \
-        0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0a,0x0b,0x0c,0x0d,0x0e,0x0f,      \
+#define BYTES_OK {                                                                       \
+        0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0a,0x0b,0x0c,0x0d,0x0e,0x0f, \
         0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17,0x18,0x19,0x1a,0x1b,0x1c,0x1d,0x1e,0x1f, \
         0x20,0x21,0x22,0x23,0x24,0x25,0x26,0x27,0x28,0x29,0x2a,0x2b,0x2c,0x2d,0x2e,0x2f, \
         0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37,0x38,0x39,0x3a,0x3b,0x3c,0x3d,0x3e,0x3f, \
         0x40,0x41,0x42,0x43,0x44,0x45,0x46,0x47,0x48,0x49,0x4a,0x4b,0x4c,0x4d,0x4e,0x4f, \
         0x50,0x51,0x52,0x53,0x54,0x55,0x56,0x57,0x58,0x59,0x5a,0x5b,0x5c,0x5d,0x5e,0x5f, \
         0x60,0x61,0x62,0x63,0x64,0x65,0x66,0x67,0x68,0x69,0x6a,0x6b,0x6c,0x6d,0x6e,0x6f, \
-        0x70,0x71,0x72,0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7a,0x7b,0x7c,0x7d,0x7e       \
+        0x70,0x71,0x72,0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7a,0x7b,0x7c,0x7d,0x7e,0x7f, \
 }
 
 TEST(config_parse_duid_rawdata) {
@@ -116,8 +126,8 @@ TEST(config_parse_duid_rawdata) {
                                            &(DUID){0, 8, {0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7}});
         test_config_parse_duid_rawdata_one("11::", 0, &(DUID){0, 1, {0x11}});  /* FIXME: should this be an error? */
         test_config_parse_duid_rawdata_one("abcdef", 0, &(DUID){});
-        test_config_parse_duid_rawdata_one(BYTES_0_126, 0, &(DUID){});
-        test_config_parse_duid_rawdata_one(&BYTES_0_126[3], 0, &(DUID){0, 126, BYTES_1_126});
+        test_config_parse_duid_rawdata_one(STR_TOO_LONG, 0, &(DUID){});
+        test_config_parse_duid_rawdata_one(STR_OK, 0, &(DUID){0, 128, BYTES_OK});
 }
 
 TEST(config_parse_ether_addr) {