net/ndrv.h

Struct: ndrv_demux_desc Purpose: To uniquely identify a packet based on its low-level framing information. Fields: type : type of protocol in data field, must be understood by the interface family of the interface the socket is bound to length : length of protocol data in "data" field data : union of framing-specific data, in network byte order ether_type : ethernet type in network byte order, assuming ethernet type II framing sap : first 3 bytes of sap header, network byte order snap : first 5 bytes of snap header, network byte order other : up to 28 bytes of protocol data for different protocol type Examples: 1) 802.1x uses ether_type 0x888e, so the descriptor would be set as: struct ndrv_demux_desc desc; desc.type = NDRV_DEMUXTYPE_ETHERTYPE desc.length = sizeof(unsigned short); desc.ether_type = htons(0x888e); 2) AppleTalk uses SNAP 0x080007809B struct ndrv_demux_desc desc; desc.type = NDRV_DEMUXTYPE_SNAP; desc.length = 5; desc.data.snap[0] = 08; desc.data.snap[1] = 00; desc.data.snap[2] = 07; desc.data.snap[3] = 80; desc.data.snap[4] = 9B;

Struct: ndrv_protocol_desc Purpose: Used to "bind" an NDRV socket so that packets that match given protocol demux descriptions can be received: Field: version : must be NDRV_PROTOCOL_DESC_VERS protocol_family : unique identifier for this protocol demux_count : number of demux_list descriptors in demux_list; maximum of 10 demux_list : pointer to array of demux descriptors

Max number of descriptions allowed by default

#define NDRV_DMUX_MAX_DESCR 1024

sysctl MIB tags at the kern.ipc.nrdv level

#define NRDV_MULTICAST_ADDRS_PER_SOCK 1