Adjusts an mbuf chain so that a given number of bytes is in contiguous memory in the data area of the head mbuf structure.
#include <sys/types.h> #include <sys/errno.h> #include <sys/mbuf.h>
struct mbuf *m_pullup ( m, size)
struct mbuf *m;
int size;
m | Specifies the mbuf chain to be adjusted. |
size | Specifies the number of bytes to be contiguous. |
The m_pullup kernel service guarantees that the mbuf structure at the head of a chain has in contiguous memory within its data area at least the number of data bytes specified by the size parameter.
The m_pullup kernel service can be called from either the process or interrupt environment.
Upon successful completion, the head structure in the altered mbuf chain is returned.
A value of null is returned and the original chain is deallocated under the following circumstances:
I/O Kernel Services in AIX 5L Version 5.2 Kernel Extensions and Device Support Programming Concepts.