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Diffstat (limited to 'src/libfreeswan/initsubnet.c')
-rw-r--r--src/libfreeswan/initsubnet.c95
1 files changed, 95 insertions, 0 deletions
diff --git a/src/libfreeswan/initsubnet.c b/src/libfreeswan/initsubnet.c
new file mode 100644
index 000000000..75ca72f36
--- /dev/null
+++ b/src/libfreeswan/initsubnet.c
@@ -0,0 +1,95 @@
+/*
+ * initialize subnet structure
+ * Copyright (C) 2000, 2002 Henry Spencer.
+ *
+ * This library is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Library General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version. See <http://www.fsf.org/copyleft/lgpl.txt>.
+ *
+ * This library 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 Library General Public
+ * License for more details.
+ *
+ * RCSID $Id: initsubnet.c,v 1.1 2004/03/15 20:35:26 as Exp $
+ */
+#include "internal.h"
+#include "freeswan.h"
+
+/*
+ - initsubnet - initialize ip_subnet from address and count
+ *
+ * The only hard part is checking for host-part bits turned on.
+ */
+err_t /* NULL for success, else string literal */
+initsubnet(addr, count, clash, dst)
+const ip_address *addr;
+int count;
+int clash; /* '0' zero host-part bits, 'x' die on them */
+ip_subnet *dst;
+{
+ unsigned char *p;
+ int n;
+ int c;
+ unsigned m;
+ int die;
+
+ dst->addr = *addr;
+ n = addrbytesptr(&dst->addr, (const unsigned char **)&p);
+ if (n == 0)
+ return "unknown address family";
+
+ switch (clash) {
+ case '0':
+ die = 0;
+ break;
+ case 'x':
+ die = 1;
+ break;
+ default:
+ return "unknown clash-control value in initsubnet";
+ break;
+ }
+
+ c = count / 8;
+ if (c > n)
+ return "impossible mask count";
+ p += c;
+ n -= c;
+
+ m = 0xff;
+ c = count % 8;
+ if (n > 0 && c != 0) /* partial byte */
+ m >>= c;
+ for (; n > 0; n--) {
+ if ((*p & m) != 0) {
+ if (die)
+ return "improper subnet, host-part bits on";
+ *p &= ~m;
+ }
+ m = 0xff;
+ p++;
+ }
+
+ dst->maskbits = count;
+ return NULL;
+}
+
+/*
+ - addrtosubnet - initialize ip_subnet from a single address
+ */
+err_t /* NULL for success, else string literal */
+addrtosubnet(addr, dst)
+const ip_address *addr;
+ip_subnet *dst;
+{
+ int n;
+
+ dst->addr = *addr;
+ n = addrbytesptr(&dst->addr, (const unsigned char **)NULL);
+ if (n == 0)
+ return "unknown address family";
+ dst->maskbits = n*8;
+ return NULL;
+}