Function os_mbuf_pullup

pub unsafe extern "C" fn os_mbuf_pullup(
    om: *mut os_mbuf,
    len: u16,
) -> *mut os_mbuf

Rearrange a mbuf chain so that len bytes are contiguous, and in the data area of an mbuf (so that OS_MBUF_DATA() will work on a structure of size len.) Returns the resulting mbuf chain on success, free’s it and returns NULL on failure.

If there is room, it will add up to “max_protohdr - len” extra bytes to the contiguous region, in an attempt to avoid being called next time.

@param omp The mbuf pool to take the mbufs out of @param om The mbuf chain to make contiguous @param len The number of bytes in the chain to make contiguous

@return The contiguous mbuf chain on success, NULL on failure.