/*
* Allocate and setup a management frame of the specified
* size. We return the mbuf and a pointer to the start
* of the contiguous data area that's been reserved based
* on the packet length. The data area is forced to 32-bit
* alignment and the buffer length to a multiple of 4 bytes.
* This is done mainly so beacon frames (that require this)
* can use this interface too.
*/
struct mbuf *
ieee80211_getmgtframe(uint8_t **frm, int headroom, int pktlen)
{
struct mbuf *m;
u_int len;
/*
* NB: we know the mbuf routines will align the data area
* so we don't need to do anything special.
*/
len = roundup2(headroom + pktlen, 4);
KASSERT(len <= MCLBYTES, ("802.11 mgt frame too large: %u", len));
if (len < MINCLSIZE) {
m = m_gethdr(M_NOWAIT, MT_DATA);
/*
* Align the data in case additional headers are added.
* This should only happen when a WEP header is added
* which only happens for shared key authentication mgt
* frames which all fit in MHLEN.
*/
if (m != NULL)
MH_ALIGN(m, len);
} else {
m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
if (m != NULL)
MC_ALIGN(m, len);
}
if (m != NULL) {
m->m_data += headroom;
*frm = m->m_data;
}
return m;
}
struct mbuf*
ieee80211_getmgtframe(uint8_t** frm, int headroom, int pktlen)
{
struct mbuf* m;
u_int len;
len = roundup2(headroom + pktlen, 4);
KASSERT(len <= MCLBYTES, ("802.11 mgt frame too large: %u", len));
if (len < MINCLSIZE) {
m = m_gethdr(M_NOWAIT, MT_DATA);
if (m != NULL)
MH_ALIGN(m, len);
} else {
m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
if (m != NULL)
MC_ALIGN(m, len);
}
if (m != NULL) {
m->m_data += headroom;
*frm = (uint8_t*)m->m_data;
}
return m;
}
