dhcp: add nm_dhcp_utils_client_id_string_to_bytes()

Generic function to convert a DHCP client identifier string in either
hex form ("aa:bb:cc") or string form ("blahblah") to bytes.

src/dhcp-manager/nm-dhcp-utils.c

@@ -692,3 +692,68 @@ nm_dhcp_utils_duid_to_string (const GByteArray *duid)
 	return g_string_free (s, FALSE);
 }
 
+/**
+ * nm_dhcp_utils_client_id_string_to_bytes:
+ * @client_id: the client ID string
+ *
+ * Accepts either a hex string ("aa:bb:cc") representing a binary client ID
+ * (the first byte is assumed to be the 'type' field per RFC 2132 section 9.14),
+ * or a string representing a non-hardware-address client ID, in which case
+ * the 'type' field is set to 0.
+ *
+ * Returns: the binary client ID suitable for sending over the wire
+ * to the DHCP server.
+ */
+GBytes *
+nm_dhcp_utils_client_id_string_to_bytes (const char *client_id)
+{
+	GBytes *bytes = NULL;
+	guint i = 0, x = 0;
+	guint len;
+	char *c;
+	int a;
+
+	g_return_val_if_fail (client_id && client_id[0], NULL);
+
+	/* Accept a binary client ID in hex digits with the ':' delimiter,
+	 * otherwise treat it as a string.
+	 */
+	len = strlen (client_id);
+	c = g_malloc0 (len / 2 + 1);
+	while (client_id[i]) {
+		a = g_ascii_xdigit_value (client_id[i++]);
+		if (a >= 0) {
+			if (client_id[i] != ':') {
+				c[x] = ((guint8) a << 4);
+				a = g_ascii_xdigit_value (client_id[i++]);
+			}
+			if (a >= 0)
+				c[x++] |= (guint8) a;
+		}
+		if (client_id[i]) {
+			if (client_id[i] != ':' || !client_id[i + 1]) {
+				/* missing or trailing ':' is invalid for hex-format */
+				a = -1;
+			}
+			i++;
+		}
+
+		if (a < 0) {
+			g_clear_pointer (&c, g_free);
+			break;
+		}
+	}
+
+	if (c) {
+		g_assert (x > 0);
+		bytes = g_bytes_new_take (c, x);
+	} else {
+		c = g_malloc (len + 1);
+		c[0] = 0;  /* type: non-hardware address per RFC 2132 section 9.14 */
+		memcpy (c + 1, client_id, len);
+		bytes = g_bytes_new_take (c, len + 1);
+	}
+
+	return bytes;
+}
+

src/dhcp-manager/nm-dhcp-utils.h

@@ -35,5 +35,7 @@ NMIP6Config *nm_dhcp_utils_ip6_config_from_options (const char *iface,
 
 char *       nm_dhcp_utils_duid_to_string          (const GByteArray *duid);
 
+GBytes *     nm_dhcp_utils_client_id_string_to_bytes (const char *client_id);
+
 #endif /* __NETWORKMANAGER_DHCP_UTILS_H__ */
 

src/dhcp-manager/tests/Makefile.am

@@ -13,7 +13,7 @@ AM_CPPFLAGS = \
 
 noinst_PROGRAMS = \
 	test-dhcp-dhclient \
-	test-dhcp-options
+	test-dhcp-utils
 
 ####### dhclient leases test #######
 
@@ -23,17 +23,17 @@ test_dhcp_dhclient_SOURCES = \
 test_dhcp_dhclient_LDADD = \
 	$(top_builddir)/src/libNetworkManager.la
 
-####### DHCP options test #######
+####### DHCP utils test #######
 
-test_dhcp_options_SOURCES = \
-	test-dhcp-options.c
+test_dhcp_utils_SOURCES = \
+	test-dhcp-utils.c
 
-test_dhcp_options_LDADD = \
+test_dhcp_utils_LDADD = \
 	$(top_builddir)/src/libNetworkManager.la
 
 #################################
 
-TESTS = test-dhcp-dhclient test-dhcp-options
+TESTS = test-dhcp-dhclient test-dhcp-utils
 
 EXTRA_DIST = \
 	test-dhclient-duid.leases \

src/dhcp-manager/tests/test-dhcp-utils.c

@@ -652,6 +652,42 @@ test_ip4_prefix_classless (void)
 	g_hash_table_destroy (options);
 }
 
+#define COMPARE_ID(src, is_str, expected, expected_len) \
+G_STMT_START { \
+	gs_unref_bytes GBytes *b = NULL; \
+	gconstpointer p; \
+	gsize l; \
+ \
+	b = nm_dhcp_utils_client_id_string_to_bytes (src); \
+	g_assert (b); \
+	p = g_bytes_get_data (b, &l); \
+	if (is_str) { \
+		g_assert_cmpint (l, ==, expected_len + 1); \
+		g_assert_cmpint (((const char *) p)[0], ==, 0); \
+		g_assert (memcmp (p + 1, expected, expected_len) == 0); \
+	} else { \
+		g_assert_cmpint (l, ==, expected_len); \
+		g_assert (memcmp (p, expected, expected_len) == 0); \
+	} \
+} G_STMT_END
+
+static void
+test_client_id_from_string (void)
+{
+	const char *nothex = "asdfasdfasdfasdfasdfasdfasdf";
+	const char *allhex = "00:11:22:33:4:55:66:77:88";
+	const guint8 allhex_bin[] = { 0x00, 0x11, 0x22, 0x33, 0x04, 0x55, 0x66, 0x77, 0x88 };
+	const char *somehex = "00:11:22:33:44:55:asdfasdfasdf:99:10";
+	const char *nocolons = "0011223344559910";
+	const char *endcolon = "00:11:22:33:44:55:";
+
+	COMPARE_ID (nothex, TRUE, nothex, strlen (nothex));
+	COMPARE_ID (allhex, FALSE, allhex_bin, sizeof (allhex_bin));
+	COMPARE_ID (somehex, TRUE, somehex, strlen (somehex));
+	COMPARE_ID (nocolons, TRUE, nocolons, strlen (nocolons));
+	COMPARE_ID (endcolon, TRUE, endcolon, strlen (endcolon));
+}
+
 NMTST_DEFINE ();
 
 int main (int argc, char **argv)
@@ -678,6 +714,7 @@ int main (int argc, char **argv)
 	g_test_add_func ("/dhcp/ip4-missing-prefix-16", test_ip4_missing_prefix_16);
 	g_test_add_func ("/dhcp/ip4-missing-prefix-8", test_ip4_missing_prefix_8);
 	g_test_add_func ("/dhcp/ip4-prefix-classless", test_ip4_prefix_classless);
+	g_test_add_func ("/dhcp/client-id-from-string", test_client_id_from_string);
 
 	return g_test_run ();
 }