sbin/dhclient/bpf.c

3 /* BPF socket interface code, originally contributed by Archie Cobbs. */
64  * Called by get_interface_list for each interface that's discovered.
65  * Opens a packet filter for each interface and adds it to the select
87 	/* Set the BPF device to point at this interface. */
89 		error("Can't attach interface %s to bpf device %s: %m",
96 			error( "Can't set the VLAN PCP tag on interface %s: %m",
149 	/* Open a BPF device and hang it on this interface... */
262 	/* Open a BPF device and hang it on this interface... */
339 send_packet_priv(struct interface_info *interface, struct imsg_hdr *hdr, int fd)
364 		assemble_hw_header(interface, buf, &bufp);
375 		result = writev(interface->wfdesc, iov, 2);
389 		result = sendmsg(interface->ufdesc, &msg, 0);
397 receive_packet(struct interface_info *interface, unsigned char *buf,
407 	 * interface.  Sigh.
415 		if (interface->rbuf_offset >= interface->rbuf_len) {
416 			length = read(interface->rfdesc, interface->rbuf,
417 			    interface->rbuf_max);
420 			interface->rbuf_offset = 0;
421 			interface->rbuf_len = length;
429 		if (interface->rbuf_len - interface->rbuf_offset <
431 			interface->rbuf_offset = interface->rbuf_len;
436 		memcpy(&hdr, &interface->rbuf[interface->rbuf_offset],
443 		if (interface->rbuf_offset + hdr.bh_hdrlen + hdr.bh_caplen >
444 		    interface->rbuf_len) {
445 			interface->rbuf_offset = interface->rbuf_len;
450 		interface->rbuf_offset += hdr.bh_hdrlen;
458 			interface->rbuf_offset =
459 			    BPF_WORDALIGN(interface->rbuf_offset +
465 		offset = decode_hw_header(interface->rbuf,
466 		    interface->rbuf_offset, hfrom);
474 			interface->rbuf_offset =
475 			    BPF_WORDALIGN(interface->rbuf_offset +
479 		interface->rbuf_offset += offset;
483 		offset = decode_udp_ip_header(interface->rbuf,
484 		    interface->rbuf_offset, from, NULL, hdr.bh_caplen);
488 			interface->rbuf_offset =
489 			    BPF_WORDALIGN(interface->rbuf_offset +
493 		interface->rbuf_offset += offset;
502 			interface->rbuf_offset =
503 			    BPF_WORDALIGN(interface->rbuf_offset +
509 		memcpy(buf, interface->rbuf + interface->rbuf_offset,
511 		interface->rbuf_offset =
512 		    BPF_WORDALIGN(interface->rbuf_offset +