---
title: mbuf_get_mlen
framework: Kernel
role: symbol
role_heading: Function
platforms: [macOS 10.4+]
path: kernel/1535699-mbuf_get_mlen
---

# mbuf_get_mlen

## Declaration

```occ
u_int32_t mbuf_get_mlen(void);
```

## Return Value

Return Value The number of bytes of available data.

## Discussion

Discussion This routine returns the number of data bytes in a normal mbuf, i.e. an mbuf that is not a packet header, nor one with an external cluster attached to it. This is equivalent to the legacy MLEN macro.