mbuf: add mbuf_write_ptr and mbuf_read_ptr

include/re_mbuf.h

@@ -60,13 +60,15 @@ int      mbuf_resize(struct mbuf *mb, size_t size);
 void     mbuf_trim(struct mbuf *mb);
 int      mbuf_shift(struct mbuf *mb, ssize_t shift);
 int      mbuf_write_mem(struct mbuf *mb, const uint8_t *buf, size_t size);
+int      mbuf_write_ptr(struct mbuf *mb, intptr_t v);
 int      mbuf_write_u8(struct mbuf *mb, uint8_t v);
 int      mbuf_write_u16(struct mbuf *mb, uint16_t v);
 int      mbuf_write_u32(struct mbuf *mb, uint32_t v);
 int      mbuf_write_u64(struct mbuf *mb, uint64_t v);
 int      mbuf_write_str(struct mbuf *mb, const char *str);
 int      mbuf_write_pl(struct mbuf *mb, const struct pl *pl);
 int      mbuf_read_mem(struct mbuf *mb, uint8_t *buf, size_t size);
+intptr_t mbuf_read_ptr(struct mbuf *mb);
 uint8_t  mbuf_read_u8(struct mbuf *mb);
 uint16_t mbuf_read_u16(struct mbuf *mb);
 uint32_t mbuf_read_u32(struct mbuf *mb);

src/mbuf/mbuf.c

@@ -260,6 +260,20 @@ int mbuf_write_mem(struct mbuf *mb, const uint8_t *buf, size_t size)
 }
 
 
+/**
+ * Write an Pointer to a memory buffer
+ *
+ * @param mb Memory buffer
+ * @param v  Pointer to write
+ *
+ * @return 0 if success, otherwise errorcode
+ */
+int mbuf_write_ptr(struct mbuf *mb, intptr_t v)
+{
+	return mbuf_write_mem(mb, (uint8_t *)&v, sizeof(v));
+}
+
+
 /**
  * Write an 8-bit value to a memory buffer
  *
@@ -378,6 +392,21 @@ int mbuf_read_mem(struct mbuf *mb, uint8_t *buf, size_t size)
 }
 
 
+/**
+ * Read an Pointer from a memory buffer
+ *
+ * @param mb Memory buffer
+ *
+ * @return Pointer
+ */
+intptr_t mbuf_read_ptr(struct mbuf *mb)
+{
+	intptr_t v;
+
+	return (0 == mbuf_read_mem(mb, (uint8_t *)&v, sizeof(v))) ? v : 0;
+}
+
+
 /**
  * Read an 8-bit value from a memory buffer
  *