1 files changed, 136 insertions, 0 deletions
diff --git a/fs/ceph/decode.h b/fs/ceph/decode.h
new file mode 100644
index 00000000000..fc2769df062
--- /dev/null
+++ b/fs/ceph/decode.h
@@ -0,0 +1,136 @@
+#ifndef __CEPH_DECODE_H
+#define __CEPH_DECODE_H
+
+#include <asm/unaligned.h>
+
+/*
+ * in all cases,
+ *   void **p     pointer to position pointer
+ *   void *end    pointer to end of buffer (last byte + 1)
+ */
+
+/*
+ * bounds check input.
+ */
+#define ceph_decode_need(p, end, n, bad)		\
+	do {						\
+		if (unlikely(*(p) + (n) > (end))) 	\
+			goto bad;			\
+	} while (0)
+
+#define ceph_decode_64(p, v)					\
+	do {							\
+		v = get_unaligned_le64(*(p));			\
+		*(p) += sizeof(u64);				\
+	} while (0)
+#define ceph_decode_32(p, v)					\
+	do {							\
+		v = get_unaligned_le32(*(p));			\
+		*(p) += sizeof(u32);				\
+	} while (0)
+#define ceph_decode_16(p, v)					\
+	do {							\
+		v = get_unaligned_le16(*(p));			\
+		*(p) += sizeof(u16);				\
+	} while (0)
+#define ceph_decode_8(p, v)				\
+	do {						\
+		v = *(u8 *)*(p);			\
+		(*p)++;					\
+	} while (0)
+
+#define ceph_decode_copy(p, pv, n)			\
+	do {						\
+		memcpy(pv, *(p), n);			\
+		*(p) += n;				\
+	} while (0)
+
+/* bounds check too */
+#define ceph_decode_64_safe(p, end, v, bad)			\
+	do {							\
+		ceph_decode_need(p, end, sizeof(u64), bad);	\
+		ceph_decode_64(p, v);				\
+	} while (0)
+#define ceph_decode_32_safe(p, end, v, bad)			\
+	do {							\
+		ceph_decode_need(p, end, sizeof(u32), bad);	\
+		ceph_decode_32(p, v);				\
+	} while (0)
+#define ceph_decode_16_safe(p, end, v, bad)			\
+	do {							\
+		ceph_decode_need(p, end, sizeof(u16), bad);	\
+		ceph_decode_16(p, v);				\
+	} while (0)
+
+#define ceph_decode_copy_safe(p, end, pv, n, bad)		\
+	do {							\
+		ceph_decode_need(p, end, n, bad);		\
+		ceph_decode_copy(p, pv, n);			\
+	} while (0)
+
+/*
+ * struct ceph_timespec <-> struct timespec
+ */
+#define ceph_decode_timespec(ts, tv)					\
+	do {								\
+		(ts)->tv_sec = le32_to_cpu((tv)->tv_sec);		\
+		(ts)->tv_nsec = le32_to_cpu((tv)->tv_nsec);		\
+	} while (0)
+#define ceph_encode_timespec(tv, ts)				\
+	do {							\
+		(tv)->tv_sec = cpu_to_le32((ts)->tv_sec);	\
+		(tv)->tv_nsec = cpu_to_le32((ts)->tv_nsec);	\
+	} while (0)
+
+
+/*
+ * encoders
+ */
+#define ceph_encode_64(p, v)						\
+	do {								\
+		put_unaligned_le64(v, (__le64 *)*(p));			\
+		*(p) += sizeof(u64);					\
+	} while (0)
+#define ceph_encode_32(p, v)					\
+	do {							\
+		put_unaligned_le32(v, (__le32 *)*(p));		\
+		*(p) += sizeof(u32);				\
+	} while (0)
+#define ceph_encode_16(p, v)					\
+	do {							\
+		put_unaligned_le16(v), (__le16 *)*(p));		\
+	*(p) += sizeof(u16);					\
+	} while (0)
+#define ceph_encode_8(p, v)			  \
+	do {					  \
+		*(u8 *)*(p) = v;		  \
+		(*(p))++;			  \
+	} while (0)
+
+/*
+ * filepath, string encoders
+ */
+static inline void ceph_encode_filepath(void **p, void *end,
+					u64 ino, const char *path)
+{
+	u32 len = path ? strlen(path) : 0;
+	BUG_ON(*p + sizeof(ino) + sizeof(len) + len > end);
+	ceph_encode_64(p, ino);
+	ceph_encode_32(p, len);
+	if (len)
+		memcpy(*p, path, len);
+	*p += len;
+}
+
+static inline void ceph_encode_string(void **p, void *end,
+				      const char *s, u32 len)
+{
+	BUG_ON(*p + sizeof(len) + len > end);
+	ceph_encode_32(p, len);
+	if (len)
+		memcpy(*p, s, len);
+	*p += len;
+}
+
+
+#endif