Function ng_etf_rcvmsg

freebsd/netgraph/ng_etf.c:246–346

* Get a netgraph control message. * We actually receive a queue item that has a pointer to the message. * If we free the item, the message will be freed too, unless we remove * it from the item using NGI_GET_MSG(); * The return address is also stored in the item, as an ng_ID_t, * accessible as NGI_RETADDR(item); * Check it is one we understand. If needed, send a response. * We could save th

 * (so that old userland programs could continue to work).
 */
static int
ng_etf_rcvmsg(node_p node, item_p item, hook_p lasthook)
{
	const etf_p etfp = NG_NODE_PRIVATE(node);
	struct ng_mesg *resp = NULL;
	int error = 0;
	struct ng_mesg *msg;

	NGI_GET_MSG(item, msg);
	/* Deal with message according to cookie and command */
	switch (msg->header.typecookie) {
	case NGM_ETF_COOKIE: 
		switch (msg->header.cmd) {
		case NGM_ETF_GET_STATUS:
		    {
			struct ng_etfstat *stats;

			NG_MKRESPONSE(resp, msg, sizeof(*stats), M_NOWAIT);
			if (!resp) {
				error = ENOMEM;
				break;
			}
			stats = (struct ng_etfstat *) resp->data;
			stats->packets_in = etfp->packets_in;
			stats->packets_out = etfp->packets_out;
			break;
		    }
		case NGM_ETF_SET_FLAG:
			if (msg->header.arglen != sizeof(u_int32_t)) {
				error = EINVAL;
				break;
			}
			etfp->flags = *((u_int32_t *) msg->data);
			break;
		case NGM_ETF_SET_FILTER:
			{
				struct ng_etffilter *f;
				struct filter *fil;
				hook_p  hook;

				/* Check message long enough for this command */
				if (msg->header.arglen != sizeof(*f)) {
					error = EINVAL;
					break;
				}

				/* Make sure hook referenced exists */
				f = (struct ng_etffilter *)msg->data;
				hook = ng_findhook(node, f->matchhook);
				if (hook == NULL) {
					error = ENOENT;
					break;
				}

				/* and is not the downstream hook */
				if (hook == etfp->downstream_hook.hook) {
					error = EINVAL;
					break;