Function ng_pppoe_rcvdata_ether

freebsd/netgraph/ng_pppoe.c:1558–1961

* Receive data from ether and do something with it. */

 * Receive data from ether and do something with it.
 */
static int
ng_pppoe_rcvdata_ether(hook_p hook, item_p item)
{
	node_p			node = NG_HOOK_NODE(hook);
	const priv_p		privp = NG_NODE_PRIVATE(node);
	sessp			sp;
	const struct pppoe_tag	*utag = NULL, *tag = NULL;
	const struct pppoe_tag	sntag = { PTT_SRV_NAME, 0 };
	const struct pppoe_full_hdr *wh;
	const struct pppoe_hdr	*ph;
	negp			neg = NULL;
	struct mbuf		*m;
	hook_p 			sendhook;
	int			error = 0;
	uint16_t		session;
	uint16_t		length;
	uint8_t			code;
	struct	mbuf 		*m0;

	CTR6(KTR_NET, "%20s: node [%x] (%p) received %p on \"%s\" (%p)",
	    __func__, node->nd_ID, node, item, hook->hk_name, hook);

	NGI_GET_M(item, m);
	/*
	 * Dig out various fields from the packet.
	 * Use them to decide where to send it.
	 */
	privp->packets_in++;
	if( m->m_len < sizeof(*wh)) {
		m = m_pullup(m, sizeof(*wh)); /* Checks length */
		if (m == NULL) {
			log(LOG_NOTICE, "ng_pppoe[%x]: couldn't "
			    "m_pullup(wh)\n", node->nd_ID);
			LEAVE(ENOBUFS);
		}
	}
	wh = mtod(m, struct pppoe_full_hdr *);
	length = ntohs(wh->ph.length);
	switch(wh->eh.ether_type) {
	case	ETHERTYPE_PPPOE_3COM_DISC: /* fall through */
	case	ETHERTYPE_PPPOE_DISC:
		/*
		 * We need to try to make sure that the tag area
		 * is contiguous, or we could wander off the end
		 * of a buffer and make a mess.
		 * (Linux wouldn't have this problem).
		 */
		if (m->m_pkthdr.len <= MHLEN) {
			if( m->m_len < m->m_pkthdr.len) {
				m = m_pullup(m, m->m_pkthdr.len);
				if (m == NULL) {
					log(LOG_NOTICE, "ng_pppoe[%x]: "
					    "couldn't m_pullup(pkthdr)\n",
					    node->nd_ID);
					LEAVE(ENOBUFS);
				}
			}
		}