[linux.git] / net / llc / llc_sap.c

/*
 * llc_sap.c - driver routines for SAP component.
 *
 * Copyright (c) 1997 by Procom Technology, Inc.
 * 		 2001-2003 by Arnaldo Carvalho de Melo <[email protected]>
 *
 * This program can be redistributed or modified under the terms of the
 * GNU General Public License as published by the Free Software Foundation.
 * This program is distributed without any warranty or implied warranty
 * of merchantability or fitness for a particular purpose.
 *
 * See the GNU General Public License for more details.
 */

#include <net/llc.h>
#include <net/llc_if.h>
#include <net/llc_conn.h>
#include <net/llc_pdu.h>
#include <net/llc_sap.h>
#include <net/llc_s_ac.h>
#include <net/llc_s_ev.h>
#include <net/llc_s_st.h>
#include <net/sock.h>
#include <net/tcp_states.h>
#include <linux/llc.h>

/**
 *	llc_alloc_frame - allocates sk_buff for frame
 *	@dev: network device this skb will be sent over
 *
 *	Allocates an sk_buff for frame and initializes sk_buff fields.
 *	Returns allocated skb or %NULL when out of memory.
 */
struct sk_buff *llc_alloc_frame(struct sock *sk, struct net_device *dev)
{
	struct sk_buff *skb = alloc_skb(128, GFP_ATOMIC);

	if (skb) {
		skb_reset_mac_header(skb);
		skb_reserve(skb, 50);
		skb_reset_network_header(skb);
		skb_reset_transport_header(skb);
		skb->protocol = htons(ETH_P_802_2);
		skb->dev      = dev;
		if (sk != NULL)
			skb_set_owner_w(skb, sk);
	}
	return skb;
}

void llc_save_primitive(struct sock *sk, struct sk_buff* skb, u8 prim)
{
	struct sockaddr_llc *addr;

       /* save primitive for use by the user. */
	addr		  = llc_ui_skb_cb(skb);

	memset(addr, 0, sizeof(*addr));
	addr->sllc_family = sk->sk_family;
	addr->sllc_arphrd = skb->dev->type;
	addr->sllc_test   = prim == LLC_TEST_PRIM;
	addr->sllc_xid    = prim == LLC_XID_PRIM;
	addr->sllc_ua     = prim == LLC_DATAUNIT_PRIM;
	llc_pdu_decode_sa(skb, addr->sllc_mac);
	llc_pdu_decode_ssap(skb, &addr->sllc_sap);
}

/**
 *	llc_sap_rtn_pdu - Informs upper layer on rx of an UI, XID or TEST pdu.
 *	@sap: pointer to SAP
 *	@skb: received pdu
 */
void llc_sap_rtn_pdu(struct llc_sap *sap, struct sk_buff *skb)
{
	struct llc_sap_state_ev *ev = llc_sap_ev(skb);
	struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);

	switch (LLC_U_PDU_RSP(pdu)) {
	case LLC_1_PDU_CMD_TEST:
		ev->prim = LLC_TEST_PRIM;	break;
	case LLC_1_PDU_CMD_XID:
		ev->prim = LLC_XID_PRIM;	break;
	case LLC_1_PDU_CMD_UI:
		ev->prim = LLC_DATAUNIT_PRIM;	break;
	}
	ev->ind_cfm_flag = LLC_IND;
}

/**
 *	llc_find_sap_trans - finds transition for event
 *	@sap: pointer to SAP
 *	@skb: happened event
 *
 *	This function finds transition that matches with happened event.
 *	Returns the pointer to found transition on success or %NULL for
 *	failure.
 */
static struct llc_sap_state_trans *llc_find_sap_trans(struct llc_sap *sap,
						      struct sk_buff* skb)
{
	int i = 0;
	struct llc_sap_state_trans *rc = NULL;
	struct llc_sap_state_trans **next_trans;
	struct llc_sap_state *curr_state = &llc_sap_state_table[sap->state - 1];
	/*
	 * Search thru events for this state until list exhausted or until
	 * its obvious the event is not valid for the current state
	 */
	for (next_trans = curr_state->transitions; next_trans[i]->ev; i++)
		if (!next_trans[i]->ev(sap, skb)) {
			rc = next_trans[i]; /* got event match; return it */
			break;
		}
	return rc;
}

/**
 *	llc_exec_sap_trans_actions - execute actions related to event
 *	@sap: pointer to SAP
 *	@trans: pointer to transition that it's actions must be performed
 *	@skb: happened event.
 *
 *	This function executes actions that is related to happened event.
 *	Returns 0 for success and 1 for failure of at least one action.
 */
static int llc_exec_sap_trans_actions(struct llc_sap *sap,
				      struct llc_sap_state_trans *trans,
				      struct sk_buff *skb)
{
	int rc = 0;
	llc_sap_action_t *next_action = trans->ev_actions;

	for (; next_action && *next_action; next_action++)
		if ((*next_action)(sap, skb))
			rc = 1;
	return rc;
}

/**
 *	llc_sap_next_state - finds transition, execs actions & change SAP state
 *	@sap: pointer to SAP
 *	@skb: happened event
 *
 *	This function finds transition that matches with happened event, then
 *	executes related actions and finally changes state of SAP. It returns
 *	0 on success and 1 for failure.
 */
static int llc_sap_next_state(struct llc_sap *sap, struct sk_buff *skb)
{
	int rc = 1;
	struct llc_sap_state_trans *trans;

	if (sap->state > LLC_NR_SAP_STATES)
		goto out;
	trans = llc_find_sap_trans(sap, skb);
	if (!trans)
		goto out;
	/*
	 * Got the state to which we next transition; perform the actions
	 * associated with this transition before actually transitioning to the
	 * next state
	 */
	rc = llc_exec_sap_trans_actions(sap, trans, skb);
	if (rc)
		goto out;
	/*
	 * Transition SAP to next state if all actions execute successfully
	 */
	sap->state = trans->next_state;
out:
	return rc;
}

/**
 *	llc_sap_state_process - sends event to SAP state machine
 *	@sap: sap to use
 *	@skb: pointer to occurred event
 *
 *	After executing actions of the event, upper layer will be indicated
 *	if needed(on receiving an UI frame). sk can be null for the
 *	datalink_proto case.
 */
static void llc_sap_state_process(struct llc_sap *sap, struct sk_buff *skb)
{
	struct llc_sap_state_ev *ev = llc_sap_ev(skb);

	/*
	 * We have to hold the skb, because llc_sap_next_state
	 * will kfree it in the sending path and we need to
	 * look at the skb->cb, where we encode llc_sap_state_ev.
	 */
	skb_get(skb);
	ev->ind_cfm_flag = 0;
	llc_sap_next_state(sap, skb);
	if (ev->ind_cfm_flag == LLC_IND) {
		if (skb->sk->sk_state == TCP_LISTEN)
			kfree_skb(skb);
		else {
			llc_save_primitive(skb->sk, skb, ev->prim);

			/* queue skb to the user. */
			if (sock_queue_rcv_skb(skb->sk, skb))
				kfree_skb(skb);
		}
	}
	kfree_skb(skb);
}

/**
 *	llc_build_and_send_test_pkt - TEST interface for upper layers.
 *	@sap: sap to use
 *	@skb: packet to send
 *	@dmac: destination mac address
 *	@dsap: destination sap
 *
 *	This function is called when upper layer wants to send a TEST pdu.
 *	Returns 0 for success, 1 otherwise.
 */
void llc_build_and_send_test_pkt(struct llc_sap *sap,
				 struct sk_buff *skb, u8 *dmac, u8 dsap)
{
	struct llc_sap_state_ev *ev = llc_sap_ev(skb);

	ev->saddr.lsap = sap->laddr.lsap;
	ev->daddr.lsap = dsap;
	memcpy(ev->saddr.mac, skb->dev->dev_addr, IFHWADDRLEN);
	memcpy(ev->daddr.mac, dmac, IFHWADDRLEN);

	ev->type      = LLC_SAP_EV_TYPE_PRIM;
	ev->prim      = LLC_TEST_PRIM;
	ev->prim_type = LLC_PRIM_TYPE_REQ;
	llc_sap_state_process(sap, skb);
}

/**
 *	llc_build_and_send_xid_pkt - XID interface for upper layers
 *	@sap: sap to use
 *	@skb: packet to send
 *	@dmac: destination mac address
 *	@dsap: destination sap
 *
 *	This function is called when upper layer wants to send a XID pdu.
 *	Returns 0 for success, 1 otherwise.
 */
void llc_build_and_send_xid_pkt(struct llc_sap *sap, struct sk_buff *skb,
				u8 *dmac, u8 dsap)
{
	struct llc_sap_state_ev *ev = llc_sap_ev(skb);

	ev->saddr.lsap = sap->laddr.lsap;
	ev->daddr.lsap = dsap;
	memcpy(ev->saddr.mac, skb->dev->dev_addr, IFHWADDRLEN);
	memcpy(ev->daddr.mac, dmac, IFHWADDRLEN);

	ev->type      = LLC_SAP_EV_TYPE_PRIM;
	ev->prim      = LLC_XID_PRIM;
	ev->prim_type = LLC_PRIM_TYPE_REQ;
	llc_sap_state_process(sap, skb);
}

/**
 *	llc_sap_rcv - sends received pdus to the sap state machine
 *	@sap: current sap component structure.
 *	@skb: received frame.
 *
 *	Sends received pdus to the sap state machine.
 */
static void llc_sap_rcv(struct llc_sap *sap, struct sk_buff *skb)
{
	struct llc_sap_state_ev *ev = llc_sap_ev(skb);

	ev->type   = LLC_SAP_EV_TYPE_PDU;
	ev->reason = 0;
	llc_sap_state_process(sap, skb);
}

/**
 *	llc_lookup_dgram - Finds dgram socket for the local sap/mac
 *	@sap: SAP
 *	@laddr: address of local LLC (MAC + SAP)
 *
 *	Search socket list of the SAP and finds connection using the local
 *	mac, and local sap. Returns pointer for socket found, %NULL otherwise.
 */
static struct sock *llc_lookup_dgram(struct llc_sap *sap,
				     const struct llc_addr *laddr)
{
	struct sock *rc;
	struct hlist_node *node;

	read_lock_bh(&sap->sk_list.lock);
	sk_for_each(rc, node, &sap->sk_list.list) {
		struct llc_sock *llc = llc_sk(rc);

		if (rc->sk_type == SOCK_DGRAM &&
		    llc->laddr.lsap == laddr->lsap &&
		    llc_mac_match(llc->laddr.mac, laddr->mac)) {
			sock_hold(rc);
			goto found;
		}
	}
	rc = NULL;
found:
	read_unlock_bh(&sap->sk_list.lock);
	return rc;
}

/**
 * 	llc_sap_mcast - Deliver multicast PDU's to all matching datagram sockets.
 *	@sap: SAP
 *	@laddr: address of local LLC (MAC + SAP)
 *
 *	Search socket list of the SAP and finds connections with same sap.
 *	Deliver clone to each.
 */
static void llc_sap_mcast(struct llc_sap *sap,
			  const struct llc_addr *laddr,
			  struct sk_buff *skb)
{
	struct sock *sk;
	struct hlist_node *node;

	read_lock_bh(&sap->sk_list.lock);
	sk_for_each(sk, node, &sap->sk_list.list) {
		struct llc_sock *llc = llc_sk(sk);
		struct sk_buff *skb1;

		if (sk->sk_type != SOCK_DGRAM)
			continue;

		if (llc->laddr.lsap != laddr->lsap)
			continue;

		if (llc->dev != skb->dev)
			continue;

		skb1 = skb_clone(skb, GFP_ATOMIC);
		if (!skb1)
			break;

		sock_hold(sk);
		skb_set_owner_r(skb1, sk);
		llc_sap_rcv(sap, skb1);
		sock_put(sk);
	}
	read_unlock_bh(&sap->sk_list.lock);
}


void llc_sap_handler(struct llc_sap *sap, struct sk_buff *skb)
{
	struct llc_addr laddr;

	llc_pdu_decode_da(skb, laddr.mac);
	llc_pdu_decode_dsap(skb, &laddr.lsap);

	if (llc_mac_multicast(laddr.mac)) {
		llc_sap_mcast(sap, &laddr, skb);
		kfree_skb(skb);
	} else {
		struct sock *sk = llc_lookup_dgram(sap, &laddr);
		if (sk) {
			skb_set_owner_r(skb, sk);
			llc_sap_rcv(sap, skb);
			sock_put(sk);
		} else
			kfree_skb(skb);
	}
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* llc_sap.c - driver routines for SAP component.
	3	*
	4	* Copyright (c) 1997 by Procom Technology, Inc.
	5	* 2001-2003 by Arnaldo Carvalho de Melo <[email protected]>
	6	*
	7	* This program can be redistributed or modified under the terms of the
	8	* GNU General Public License as published by the Free Software Foundation.
	9	* This program is distributed without any warranty or implied warranty
	10	* of merchantability or fitness for a particular purpose.
	11	*
	12	* See the GNU General Public License for more details.
	13	*/
	14
	15	#include <net/llc.h>
	16	#include <net/llc_if.h>
	17	#include <net/llc_conn.h>
	18	#include <net/llc_pdu.h>
	19	#include <net/llc_sap.h>
	20	#include <net/llc_s_ac.h>
	21	#include <net/llc_s_ev.h>
	22	#include <net/llc_s_st.h>
	23	#include <net/sock.h>
c752f073	24	#include <net/tcp_states.h>
1da177e4 LT	25	#include <linux/llc.h>
	26
	27	/**
	28	* llc_alloc_frame - allocates sk_buff for frame
1d67e650	29	* @dev: network device this skb will be sent over
1da177e4 LT	30	*
	31	* Allocates an sk_buff for frame and initializes sk_buff fields.
	32	* Returns allocated skb or %NULL when out of memory.
	33	*/
d389424e	34	struct sk_buff llc_alloc_frame(struct sock sk, struct net_device *dev)
1da177e4 LT	35	{
	36	struct sk_buff *skb = alloc_skb(128, GFP_ATOMIC);
	37
	38	if (skb) {
0a1b0ad9	39	skb_reset_mac_header(skb);
1da177e4	40	skb_reserve(skb, 50);
c1d2bbe1	41	skb_reset_network_header(skb);
badff6d0	42	skb_reset_transport_header(skb);
1da177e4	43	skb->protocol = htons(ETH_P_802_2);
1d67e650	44	skb->dev = dev;
d389424e ACM	45	if (sk != NULL)
d389424e ACM	46	skb_set_owner_w(skb, sk);
1da177e4 LT	47	}
	48	return skb;
	49	}
	50
04e4223f	51	void llc_save_primitive(struct sock sk, struct sk_buff skb, u8 prim)
1da177e4	52	{
8420e1b5	53	struct sockaddr_llc *addr;
1da177e4 LT	54
1da177e4 LT	55	/* save primitive for use by the user. */
8420e1b5	56	addr = llc_ui_skb_cb(skb);
30a584d9 SH	57
30a584d9 SH	58	memset(addr, 0, sizeof(*addr));
04e4223f	59	addr->sllc_family = sk->sk_family;
1da177e4 LT	60	addr->sllc_arphrd = skb->dev->type;
	61	addr->sllc_test = prim == LLC_TEST_PRIM;
	62	addr->sllc_xid = prim == LLC_XID_PRIM;
	63	addr->sllc_ua = prim == LLC_DATAUNIT_PRIM;
	64	llc_pdu_decode_sa(skb, addr->sllc_mac);
	65	llc_pdu_decode_ssap(skb, &addr->sllc_sap);
	66	}
	67
	68	/**
	69	* llc_sap_rtn_pdu - Informs upper layer on rx of an UI, XID or TEST pdu.
	70	* @sap: pointer to SAP
	71	* @skb: received pdu
	72	*/
	73	void llc_sap_rtn_pdu(struct llc_sap sap, struct sk_buff skb)
	74	{
	75	struct llc_sap_state_ev *ev = llc_sap_ev(skb);
	76	struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
	77
	78	switch (LLC_U_PDU_RSP(pdu)) {
	79	case LLC_1_PDU_CMD_TEST:
	80	ev->prim = LLC_TEST_PRIM; break;
	81	case LLC_1_PDU_CMD_XID:
	82	ev->prim = LLC_XID_PRIM; break;
	83	case LLC_1_PDU_CMD_UI:
	84	ev->prim = LLC_DATAUNIT_PRIM; break;
	85	}
	86	ev->ind_cfm_flag = LLC_IND;
	87	}
	88
	89	/**
	90	* llc_find_sap_trans - finds transition for event
	91	* @sap: pointer to SAP
	92	* @skb: happened event
	93	*
	94	* This function finds transition that matches with happened event.
	95	* Returns the pointer to found transition on success or %NULL for
	96	* failure.
	97	*/
	98	static struct llc_sap_state_trans llc_find_sap_trans(struct llc_sap sap,
	99	struct sk_buff* skb)
	100	{
	101	int i = 0;
	102	struct llc_sap_state_trans *rc = NULL;
	103	struct llc_sap_state_trans **next_trans;
	104	struct llc_sap_state *curr_state = &llc_sap_state_table[sap->state - 1];
	105	/*
	106	* Search thru events for this state until list exhausted or until
	107	* its obvious the event is not valid for the current state
	108	*/
	109	for (next_trans = curr_state->transitions; next_trans[i]->ev; i++)
	110	if (!next_trans[i]->ev(sap, skb)) {
	111	rc = next_trans[i]; /* got event match; return it */
	112	break;
	113	}
	114	return rc;
	115	}
	116
	117	/**
	118	* llc_exec_sap_trans_actions - execute actions related to event
	119	* @sap: pointer to SAP
	120	* @trans: pointer to transition that it's actions must be performed
	121	* @skb: happened event.
	122	*
	123	* This function executes actions that is related to happened event.
124	* Returns 0 for success and 1 for failure of at least one action.
125	*/
126	static int llc_exec_sap_trans_actions(struct llc_sap *sap,
127	struct llc_sap_state_trans *trans,
128	struct sk_buff *skb)
129	{
130	int rc = 0;
131	llc_sap_action_t *next_action = trans->ev_actions;
132
133	for (; next_action && *next_action; next_action++)
134	if ((*next_action)(sap, skb))
135	rc = 1;
136	return rc;
137	}
138
139	/**
140	* llc_sap_next_state - finds transition, execs actions & change SAP state
141	* @sap: pointer to SAP
142	* @skb: happened event
143	*
144	* This function finds transition that matches with happened event, then
145	* executes related actions and finally changes state of SAP. It returns
146	* 0 on success and 1 for failure.
147	*/
148	static int llc_sap_next_state(struct llc_sap sap, struct sk_buff skb)
149	{
150	int rc = 1;
151	struct llc_sap_state_trans *trans;
152
153	if (sap->state > LLC_NR_SAP_STATES)
154	goto out;
155	trans = llc_find_sap_trans(sap, skb);
156	if (!trans)
157	goto out;
158	/*
159	* Got the state to which we next transition; perform the actions
160	* associated with this transition before actually transitioning to the
161	* next state
162	*/
163	rc = llc_exec_sap_trans_actions(sap, trans, skb);
164	if (rc)
165	goto out;
166	/*
167	* Transition SAP to next state if all actions execute successfully
168	*/
169	sap->state = trans->next_state;
170	out:
171	return rc;
172	}
173
174	/**
175	* llc_sap_state_process - sends event to SAP state machine
176	* @sap: sap to use
177	* @skb: pointer to occurred event
178	*
179	* After executing actions of the event, upper layer will be indicated
180	* if needed(on receiving an UI frame). sk can be null for the
181	* datalink_proto case.
182	*/
183	static void llc_sap_state_process(struct llc_sap sap, struct sk_buff skb)
184	{
185	struct llc_sap_state_ev *ev = llc_sap_ev(skb);
186
187	/*
188	* We have to hold the skb, because llc_sap_next_state
189	* will kfree it in the sending path and we need to
190	* look at the skb->cb, where we encode llc_sap_state_ev.
191	*/
192	skb_get(skb);
193	ev->ind_cfm_flag = 0;
194	llc_sap_next_state(sap, skb);
195	if (ev->ind_cfm_flag == LLC_IND) {
196	if (skb->sk->sk_state == TCP_LISTEN)
197	kfree_skb(skb);
198	else {
04e4223f	199	llc_save_primitive(skb->sk, skb, ev->prim);
1da177e4 LT	200
	201	/* queue skb to the user. */
	202	if (sock_queue_rcv_skb(skb->sk, skb))
	203	kfree_skb(skb);
	204	}
d57b1869	205	}
1da177e4 LT	206	kfree_skb(skb);
	207	}
	208
	209	/**
	210	* llc_build_and_send_test_pkt - TEST interface for upper layers.
	211	* @sap: sap to use
	212	* @skb: packet to send
	213	* @dmac: destination mac address
	214	* @dsap: destination sap
	215	*
	216	* This function is called when upper layer wants to send a TEST pdu.
	217	* Returns 0 for success, 1 otherwise.
	218	*/
d57b1869	219	void llc_build_and_send_test_pkt(struct llc_sap *sap,
1da177e4 LT	220	struct sk_buff skb, u8 dmac, u8 dsap)
	221	{
	222	struct llc_sap_state_ev *ev = llc_sap_ev(skb);
	223
	224	ev->saddr.lsap = sap->laddr.lsap;
	225	ev->daddr.lsap = dsap;
	226	memcpy(ev->saddr.mac, skb->dev->dev_addr, IFHWADDRLEN);
	227	memcpy(ev->daddr.mac, dmac, IFHWADDRLEN);
d57b1869	228
1da177e4 LT	229	ev->type = LLC_SAP_EV_TYPE_PRIM;
	230	ev->prim = LLC_TEST_PRIM;
	231	ev->prim_type = LLC_PRIM_TYPE_REQ;
	232	llc_sap_state_process(sap, skb);
	233	}
	234
	235	/**
	236	* llc_build_and_send_xid_pkt - XID interface for upper layers
	237	* @sap: sap to use
	238	* @skb: packet to send
	239	* @dmac: destination mac address
	240	* @dsap: destination sap
	241	*
	242	* This function is called when upper layer wants to send a XID pdu.
	243	* Returns 0 for success, 1 otherwise.
	244	*/
	245	void llc_build_and_send_xid_pkt(struct llc_sap sap, struct sk_buff skb,
	246	u8 *dmac, u8 dsap)
	247	{
	248	struct llc_sap_state_ev *ev = llc_sap_ev(skb);
	249
	250	ev->saddr.lsap = sap->laddr.lsap;
	251	ev->daddr.lsap = dsap;
	252	memcpy(ev->saddr.mac, skb->dev->dev_addr, IFHWADDRLEN);
	253	memcpy(ev->daddr.mac, dmac, IFHWADDRLEN);
	254
	255	ev->type = LLC_SAP_EV_TYPE_PRIM;
	256	ev->prim = LLC_XID_PRIM;
	257	ev->prim_type = LLC_PRIM_TYPE_REQ;
	258	llc_sap_state_process(sap, skb);
	259	}
	260
	261	/**
	262	* llc_sap_rcv - sends received pdus to the sap state machine
	263	* @sap: current sap component structure.
	264	* @skb: received frame.
	265	*
	266	* Sends received pdus to the sap state machine.
	267	*/
	268	static void llc_sap_rcv(struct llc_sap sap, struct sk_buff skb)
	269	{
	270	struct llc_sap_state_ev *ev = llc_sap_ev(skb);
	271
	272	ev->type = LLC_SAP_EV_TYPE_PDU;
	273	ev->reason = 0;
	274	llc_sap_state_process(sap, skb);
	275	}
	276
	277	/**
	278	* llc_lookup_dgram - Finds dgram socket for the local sap/mac
	279	* @sap: SAP
	280	* @laddr: address of local LLC (MAC + SAP)
	281	*
	282	* Search socket list of the SAP and finds connection using the local
	283	* mac, and local sap. Returns pointer for socket found, %NULL otherwise.
	284	*/
	285	static struct sock llc_lookup_dgram(struct llc_sap sap,
bc0e6467	286	const struct llc_addr *laddr)
1da177e4 LT	287	{
	288	struct sock *rc;
	289	struct hlist_node *node;
	290
	291	read_lock_bh(&sap->sk_list.lock);
	292	sk_for_each(rc, node, &sap->sk_list.list) {
	293	struct llc_sock *llc = llc_sk(rc);
	294
	295	if (rc->sk_type == SOCK_DGRAM &&
	296	llc->laddr.lsap == laddr->lsap &&
	297	llc_mac_match(llc->laddr.mac, laddr->mac)) {
	298	sock_hold(rc);
	299	goto found;
	300	}
	301	}
	302	rc = NULL;
	303	found:
	304	read_unlock_bh(&sap->sk_list.lock);
	305	return rc;
	306	}
	307
bc0e6467 SH	308	/**
	309	* llc_sap_mcast - Deliver multicast PDU's to all matching datagram sockets.
	310	* @sap: SAP
	311	* @laddr: address of local LLC (MAC + SAP)
	312	*
	313	* Search socket list of the SAP and finds connections with same sap.
	314	* Deliver clone to each.
	315	*/
	316	static void llc_sap_mcast(struct llc_sap *sap,
	317	const struct llc_addr *laddr,
	318	struct sk_buff *skb)
	319	{
	320	struct sock *sk;
	321	struct hlist_node *node;
	322
	323	read_lock_bh(&sap->sk_list.lock);
	324	sk_for_each(sk, node, &sap->sk_list.list) {
	325	struct llc_sock *llc = llc_sk(sk);
	326	struct sk_buff *skb1;
	327
	328	if (sk->sk_type != SOCK_DGRAM)
	329	continue;
	330
	331	if (llc->laddr.lsap != laddr->lsap)
	332	continue;
	333
7ee66fcb SH	334	if (llc->dev != skb->dev)
	335	continue;
	336
bc0e6467 SH	337	skb1 = skb_clone(skb, GFP_ATOMIC);
	338	if (!skb1)
	339	break;
	340
	341	sock_hold(sk);
	342	skb_set_owner_r(skb1, sk);
	343	llc_sap_rcv(sap, skb1);
	344	sock_put(sk);
	345	}
	346	read_unlock_bh(&sap->sk_list.lock);
	347	}
	348
	349
1da177e4 LT	350	void llc_sap_handler(struct llc_sap sap, struct sk_buff skb)
	351	{
	352	struct llc_addr laddr;
1da177e4 LT	353
	354	llc_pdu_decode_da(skb, laddr.mac);
	355	llc_pdu_decode_dsap(skb, &laddr.lsap);
	356
bc0e6467 SH	357	if (llc_mac_multicast(laddr.mac)) {
bc0e6467 SH	358	llc_sap_mcast(sap, &laddr, skb);
1da177e4	359	kfree_skb(skb);
bc0e6467 SH	360	} else {
	361	struct sock *sk = llc_lookup_dgram(sap, &laddr);
	362	if (sk) {
	363	skb_set_owner_r(skb, sk);
	364	llc_sap_rcv(sap, skb);
	365	sock_put(sk);
	366	} else
	367	kfree_skb(skb);
	368	}
1da177e4	369	}