sbin/dhclient/bpf.c

3 /* BPF socket interface code, originally contributed by Archie Cobbs. */
59  * Called by get_interface_list for each interface that's discovered.
60  * Opens a packet filter for each interface and adds it to the select
82 	/* Set the BPF device to point at this interface. */
84 		error("Can't attach interface %s to bpf device %s: %m",
97 	 * don't need to register this interface twice.
194 	/* Open a BPF device and hang it on this interface... */
253 send_packet(struct interface_info *interface, struct dhcp_packet *raw,
264 		assemble_hw_header(interface, buf, &bufp, hto);
275 		result = writev(interface->wfdesc, iov, 2);
282 		result = sendmsg(interface->ufdesc, &msg, 0);
291 receive_packet(struct interface_info *interface, unsigned char *buf,
301 	 * interface.  Sigh.
309 		if (interface->rbuf_offset >= interface->rbuf_len) {
310 			length = read(interface->rfdesc, interface->rbuf,
311 			    interface->rbuf_max);
314 			interface->rbuf_offset = 0;
315 			interface->rbuf_len = length;
323 		if (interface->rbuf_len - interface->rbuf_offset <
325 			interface->rbuf_offset = interface->rbuf_len;
330 		memcpy(&hdr, &interface->rbuf[interface->rbuf_offset],
337 		if (interface->rbuf_offset + hdr.bh_hdrlen + hdr.bh_caplen >
338 		    interface->rbuf_len) {
339 			interface->rbuf_offset = interface->rbuf_len;
344 		interface->rbuf_offset += hdr.bh_hdrlen;
352 			interface->rbuf_offset =
353 			    BPF_WORDALIGN(interface->rbuf_offset +
359 		offset = decode_hw_header(interface->rbuf,
360 		    interface->rbuf_offset, hfrom);
368 			interface->rbuf_offset =
369 			    BPF_WORDALIGN(interface->rbuf_offset +
373 		interface->rbuf_offset += offset;
377 		offset = decode_udp_ip_header(interface->rbuf,
378 		    interface->rbuf_offset, from, NULL, hdr.bh_caplen);
382 			interface->rbuf_offset =
383 			    BPF_WORDALIGN(interface->rbuf_offset +
387 		interface->rbuf_offset += offset;
396 			interface->rbuf_offset =
397 			    BPF_WORDALIGN(interface->rbuf_offset +
403 		memcpy(buf, interface->rbuf + interface->rbuf_offset,
405 		interface->rbuf_offset =
406 		    BPF_WORDALIGN(interface->rbuf_offset +