1 /*- 2 * Copyright (c) 1991 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * This code is derived from the Stanford/CMU enet packet filter, 6 * (net/enet.c) distributed as part of 4.3BSD, and code contributed 7 * to Berkeley by Steven McCanne of Lawrence Berkeley Laboratory. 8 * 9 * %sccs.include.redist.c% 10 * 11 * @(#)bpfdesc.h 7.1 (Berkeley) 05/07/91 12 * 13 * @(#) $Header: bpfdesc.h,v 1.7 90/12/04 01:05:01 mccanne Exp $ (LBL) 14 */ 15 16 /* 17 * Descriptor associated with each open bpf file. 18 */ 19 struct bpf_d { 20 struct bpf_d *bd_next; /* Linked list of descriptors */ 21 /* 22 * Buffer slots: two mbuf clusters buffer the incoming packets. 23 * The model has three slots. Sbuf is always occupied. 24 * sbuf (store) - Receive interrupt puts packets here. 25 * hbuf (hold) - When sbuf is full, put cluster here and 26 * wakeup read (replace sbuf with fbuf). 27 * fbuf (free) - When read is done, put cluster here. 28 * On receiving, if sbuf is full and fbuf is 0, packet is dropped. 29 */ 30 caddr_t bd_sbuf; /* store slot */ 31 caddr_t bd_hbuf; /* hold slot */ 32 caddr_t bd_fbuf; /* free slot */ 33 int bd_slen; /* current length of store buffer */ 34 int bd_hlen; /* current length of hold buffer */ 35 36 int bd_bufsize; /* absolute length of buffers */ 37 38 struct bpf_if * bd_bif; /* interface descriptor */ 39 u_long bd_rtout; /* Read timeout in 'ticks' */ 40 struct bpf_insn *bd_filter; /* filter code */ 41 u_long bd_rcount; /* number of packets received */ 42 u_long bd_dcount; /* number of packets dropped */ 43 struct proc * bd_selproc; /* process that last selected us */ 44 45 u_char bd_promisc; /* true if listening promiscuously */ 46 u_char bd_state; /* idle, waiting, or timed out */ 47 u_char bd_selcoll; /* true if selects collide */ 48 u_char bd_immediate; /* true to return on packet arrival */ 49 }; 50 51 /* 52 * Descriptor associated with each attached hardware interface. 53 */ 54 struct bpf_if { 55 struct bpf_if *bif_next; /* list of all interfaces */ 56 struct bpf_d *bif_dlist; /* descriptor list */ 57 struct bpf_if **bif_driverp; /* pointer into softc */ 58 u_int bif_dlt; /* link layer type */ 59 u_int bif_hdrlen; /* length of header (with padding) */ 60 struct ifnet *bif_ifp; /* correspoding interface */ 61 }; 62