Function ng_mppc_rcvmsg

freebsd/netgraph/ng_mppc.c:259–365

* Receive a control message */

 * Receive a control message
 */
static int
ng_mppc_rcvmsg(node_p node, item_p item, hook_p lasthook)
{
	const priv_p priv = NG_NODE_PRIVATE(node);
	struct ng_mesg *resp = NULL;
	int error = 0;
	struct ng_mesg *msg;

	NGI_GET_MSG(item, msg);
	switch (msg->header.typecookie) {
	case NGM_MPPC_COOKIE:
		switch (msg->header.cmd) {
		case NGM_MPPC_CONFIG_COMP:
		case NGM_MPPC_CONFIG_DECOMP:
		    {
			struct ng_mppc_config *const cfg
			    = (struct ng_mppc_config *)msg->data;
			const int isComp =
			    msg->header.cmd == NGM_MPPC_CONFIG_COMP;
			struct ng_mppc_dir *const d = isComp ?
			    &priv->xmit : &priv->recv;

			/* Check configuration */
			if (msg->header.arglen != sizeof(*cfg))
				ERROUT(EINVAL);
			if (cfg->enable) {
				if ((cfg->bits & ~MPPC_VALID_BITS) != 0)
					ERROUT(EINVAL);
#ifndef NETGRAPH_MPPC_COMPRESSION
				if ((cfg->bits & MPPC_BIT) != 0)
					ERROUT(EPROTONOSUPPORT);
#endif
#ifndef NETGRAPH_MPPC_ENCRYPTION
				if ((cfg->bits & MPPE_BITS) != 0)
					ERROUT(EPROTONOSUPPORT);
#endif
			} else
				cfg->bits = 0;

			/* Save return address so we can send reset-req's */
			if (!isComp)
				priv->ctrlnode = NGI_RETADDR(item);

			/* Configuration is OK, reset to it */
			d->cfg = *cfg;

#ifdef NETGRAPH_MPPC_COMPRESSION
			/* Initialize state buffers for compression */
			if (d->history != NULL) {
				free(d->history, M_NETGRAPH_MPPC);
				d->history = NULL;
			}
			if ((cfg->bits & MPPC_BIT) != 0) {
				d->history = malloc(isComp ?
				    MPPC_SizeOfCompressionHistory() :
				    MPPC_SizeOfDecompressionHistory(),
				    M_NETGRAPH_MPPC, M_NOWAIT);
				if (d->history == NULL)