1 files changed, 136 insertions, 0 deletions

diff --git a/fs/ceph/decode.h b/fs/ceph/decode.h
new file mode 100644
index 000000000000..fc2769df062d
--- /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