1 files changed, 79 insertions, 0 deletions
diff --git a/include/net/sctp/checksum.h b/include/net/sctp/checksum.h
new file mode 100644
index 000000000..1c6e6c076
--- /dev/null
+++ b/include/net/sctp/checksum.h
@@ -0,0 +1,79 @@
+/* SCTP kernel reference Implementation
+ * Copyright (c) 1999-2001 Motorola, Inc.
+ * Copyright (c) 2001-2003 International Business Machines, Corp.
+ *
+ * This file is part of the SCTP kernel reference Implementation
+ *
+ * SCTP Checksum functions
+ *
+ * The SCTP reference implementation 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, or (at your option)
+ * any later version.
+ *
+ * The SCTP reference implementation 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 GNU CC; see the file COPYING.  If not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * Please send any bug reports or fixes you make to the
+ * email address(es):
+ *    lksctp developers <linux-sctp@vger.kernel.org>
+ *
+ * Written or modified by:
+ *    Dinakaran Joseph
+ *    Jon Grimm <jgrimm@us.ibm.com>
+ *    Sridhar Samudrala <sri@us.ibm.com>
+ *
+ * Rewritten to use libcrc32c by:
+ *    Vlad Yasevich <vladislav.yasevich@hp.com>
+ */
+
+#ifndef __sctp_checksum_h__
+#define __sctp_checksum_h__
+
+#include <linux/types.h>
+#include <net/sctp/sctp.h>
+#include <linux/crc32c.h>
+#include <linux/crc32.h>
+
+static inline __wsum sctp_csum_update(const void *buff, int len, __wsum sum)
+{
+	/* This uses the crypto implementation of crc32c, which is either
+	 * implemented w/ hardware support or resolves to __crc32c_le().
+	 */
+	return (__force __wsum)crc32c((__force __u32)sum, buff, len);
+}
+
+static inline __wsum sctp_csum_combine(__wsum csum, __wsum csum2,
+				       int offset, int len)
+{
+	return (__force __wsum)__crc32c_le_combine((__force __u32)csum,
+						   (__force __u32)csum2, len);
+}
+
+static inline __le32 sctp_compute_cksum(const struct sk_buff *skb,
+					unsigned int offset)
+{
+	struct sctphdr *sh = (struct sctphdr *)(skb->data + offset);
+	const struct skb_checksum_ops ops = {
+		.update  = sctp_csum_update,
+		.combine = sctp_csum_combine,
+	};
+	__le32 old = sh->checksum;
+	__wsum new;
+
+	sh->checksum = 0;
+	new = ~__skb_checksum(skb, offset, skb->len - offset, ~(__wsum)0, &ops);
+	sh->checksum = old;
+
+	return cpu_to_le32((__force __u32)new);
+}
+
+#endif /* __sctp_checksum_h__ */