Add support for RFC 4361

1 files changed, 120 insertions, 0 deletions

diff --git a/duid.c b/duid.c
new file mode 100644
index 00000000..0376d99c
--- /dev/null
+++ b/duid.c
@@ -0,0 +1,120 @@
+/*
+ * dhcpcd - DHCP client daemon -
+ * Copyright 2006-2007 Roy Marples <uberlord@gentoo.org>
+ * 
+ * dhcpcd is an RFC2131 compliant DHCP client daemon.
+ *
+ * This is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <errno.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "config.h"
+#include "common.h"
+#include "duid.h"
+#include "logger.h"
+
+#ifdef ENABLE_DUID
+#define DUID_LEN                   130
+
+#define THIRTY_YEARS_IN_SECONDS    946707779
+
+void get_duid (interface_t *iface)
+{
+	FILE *fp;
+	uint16_t type = 0;
+	uint16_t hw = 0;
+	uint32_t ul;
+	time_t t;
+	unsigned char *p = iface->duid;
+	int x = 0;
+
+	if (! iface)
+		return;
+
+	/* Remove any existing */
+	iface->duid[0] = '\0';
+	iface->duid_length = 0;
+
+	/* If we already have a DUID then use it as it's never supposed
+	 * to change once we have one even if the interfaces do */
+	if ((fp = fopen (DUIDFILE, "r"))) {
+		char *fduid;
+		char *fdp;
+		fduid = fdp = xmalloc ((sizeof (char *) * DUID_LEN * 2) + 1);
+		if (fscanf (fp, "%260s", fduid) == 1) {
+			char c[3];
+			c[2] = '\0';
+			while (*fdp) {
+				c[0] = *fdp++;
+				c[1] = *fdp++;
+				*p++ = (char) strtol (c, NULL, 16);
+			}
+		}
+		free (fduid);
+		iface->duid_length = p - iface->duid;
+		fclose (fp);
+		return;
+	}
+
+	if (errno != ENOENT) {
+		logger (LOG_ERR, "fopen `%s': %s", DUIDFILE, strerror (errno));
+		return;
+	}
+
+	/* No file? OK, lets make one based on our interface */
+	type = htons (1); /* DUI-D-LLT */
+	memcpy (p, &type, 2);
+	p += 2;
+
+	hw = htons (iface->family);
+	memcpy (p, &hw, 2);
+	p += 2;
+
+	/* time returns seconds from jan 1 1970, but DUID-LLT is
+	 * seconds from jan 1 2000 modulo 2^32 */
+	t = time (NULL) - THIRTY_YEARS_IN_SECONDS;
+	ul = htonl (t & 0xffffffff);
+	memcpy (p, &ul, 4);
+	p += 4;
+
+	/* Finally, add the MAC address of the interface */
+	memcpy (p, iface->hwaddr, iface->hwlen);
+	p += iface->hwlen;
+	
+	iface->duid_length = p - iface->duid;
+
+	if (! (fp = fopen (DUIDFILE, "w")))
+		logger (LOG_ERR, "fopen `%s': %s", DUIDFILE, strerror (errno));
+	else {
+		int i;
+		for (i = 0; i < iface->duid_length; i++)
+			x += fprintf (fp, "%.2X", iface->duid[i]);
+		fprintf (fp, "\n");
+		fclose (fp);
+	}
+
+	/* Failed to write the duid? scrub it, we cannot use it */
+	if (x < 1) {
+		memset (iface->duid, 0, sizeof (iface->duid));
+		iface->duid_length = 0;
+	}
+}
+#endif