/* * 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; }