11da177e4SLinus Torvalds /*
21da177e4SLinus Torvalds * llc_sap.c - driver routines for SAP component.
31da177e4SLinus Torvalds *
41da177e4SLinus Torvalds * Copyright (c) 1997 by Procom Technology, Inc.
51da177e4SLinus Torvalds * 2001-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
61da177e4SLinus Torvalds *
71da177e4SLinus Torvalds * This program can be redistributed or modified under the terms of the
81da177e4SLinus Torvalds * GNU General Public License as published by the Free Software Foundation.
91da177e4SLinus Torvalds * This program is distributed without any warranty or implied warranty
101da177e4SLinus Torvalds * of merchantability or fitness for a particular purpose.
111da177e4SLinus Torvalds *
121da177e4SLinus Torvalds * See the GNU General Public License for more details.
131da177e4SLinus Torvalds */
141da177e4SLinus Torvalds
151da177e4SLinus Torvalds #include <net/llc.h>
161da177e4SLinus Torvalds #include <net/llc_if.h>
171da177e4SLinus Torvalds #include <net/llc_conn.h>
181da177e4SLinus Torvalds #include <net/llc_pdu.h>
191da177e4SLinus Torvalds #include <net/llc_sap.h>
201da177e4SLinus Torvalds #include <net/llc_s_ac.h>
211da177e4SLinus Torvalds #include <net/llc_s_ev.h>
221da177e4SLinus Torvalds #include <net/llc_s_st.h>
231da177e4SLinus Torvalds #include <net/sock.h>
24c752f073SArnaldo Carvalho de Melo #include <net/tcp_states.h>
251da177e4SLinus Torvalds #include <linux/llc.h>
265a0e3ad6STejun Heo #include <linux/slab.h>
271da177e4SLinus Torvalds
llc_mac_header_len(unsigned short devtype)28f83f1768SJoonwoo Park static int llc_mac_header_len(unsigned short devtype)
29f83f1768SJoonwoo Park {
30f83f1768SJoonwoo Park switch (devtype) {
31f83f1768SJoonwoo Park case ARPHRD_ETHER:
32f83f1768SJoonwoo Park case ARPHRD_LOOPBACK:
33f83f1768SJoonwoo Park return sizeof(struct ethhdr);
34f83f1768SJoonwoo Park }
35f83f1768SJoonwoo Park return 0;
36f83f1768SJoonwoo Park }
37f83f1768SJoonwoo Park
381da177e4SLinus Torvalds /**
391da177e4SLinus Torvalds * llc_alloc_frame - allocates sk_buff for frame
4074c950c9SAndrew Lunn * @sk: socket to allocate frame to
411d67e650SArnaldo Carvalho de Melo * @dev: network device this skb will be sent over
42f83f1768SJoonwoo Park * @type: pdu type to allocate
43f83f1768SJoonwoo Park * @data_size: data size to allocate
441da177e4SLinus Torvalds *
451da177e4SLinus Torvalds * Allocates an sk_buff for frame and initializes sk_buff fields.
461da177e4SLinus Torvalds * Returns allocated skb or %NULL when out of memory.
471da177e4SLinus Torvalds */
llc_alloc_frame(struct sock * sk,struct net_device * dev,u8 type,u32 data_size)48f83f1768SJoonwoo Park struct sk_buff *llc_alloc_frame(struct sock *sk, struct net_device *dev,
49f83f1768SJoonwoo Park u8 type, u32 data_size)
501da177e4SLinus Torvalds {
51f83f1768SJoonwoo Park int hlen = type == LLC_PDU_TYPE_U ? 3 : 4;
52f83f1768SJoonwoo Park struct sk_buff *skb;
53f83f1768SJoonwoo Park
54f83f1768SJoonwoo Park hlen += llc_mac_header_len(dev->type);
55f83f1768SJoonwoo Park skb = alloc_skb(hlen + data_size, GFP_ATOMIC);
561da177e4SLinus Torvalds
571da177e4SLinus Torvalds if (skb) {
580a1b0ad9SArnaldo Carvalho de Melo skb_reset_mac_header(skb);
59f83f1768SJoonwoo Park skb_reserve(skb, hlen);
60c1d2bbe1SArnaldo Carvalho de Melo skb_reset_network_header(skb);
61badff6d0SArnaldo Carvalho de Melo skb_reset_transport_header(skb);
621da177e4SLinus Torvalds skb->protocol = htons(ETH_P_802_2);
631d67e650SArnaldo Carvalho de Melo skb->dev = dev;
64d389424eSArnaldo Carvalho de Melo if (sk != NULL)
65d389424eSArnaldo Carvalho de Melo skb_set_owner_w(skb, sk);
661da177e4SLinus Torvalds }
671da177e4SLinus Torvalds return skb;
681da177e4SLinus Torvalds }
691da177e4SLinus Torvalds
llc_save_primitive(struct sock * sk,struct sk_buff * skb,u8 prim)7004e4223fSArnaldo Carvalho de Melo void llc_save_primitive(struct sock *sk, struct sk_buff *skb, u8 prim)
711da177e4SLinus Torvalds {
728420e1b5SArnaldo Carvalho de Melo struct sockaddr_llc *addr;
731da177e4SLinus Torvalds
741da177e4SLinus Torvalds /* save primitive for use by the user. */
758420e1b5SArnaldo Carvalho de Melo addr = llc_ui_skb_cb(skb);
7630a584d9SStephen Hemminger
7730a584d9SStephen Hemminger memset(addr, 0, sizeof(*addr));
7804e4223fSArnaldo Carvalho de Melo addr->sllc_family = sk->sk_family;
791da177e4SLinus Torvalds addr->sllc_arphrd = skb->dev->type;
801da177e4SLinus Torvalds addr->sllc_test = prim == LLC_TEST_PRIM;
811da177e4SLinus Torvalds addr->sllc_xid = prim == LLC_XID_PRIM;
821da177e4SLinus Torvalds addr->sllc_ua = prim == LLC_DATAUNIT_PRIM;
831da177e4SLinus Torvalds llc_pdu_decode_sa(skb, addr->sllc_mac);
841da177e4SLinus Torvalds llc_pdu_decode_ssap(skb, &addr->sllc_sap);
851da177e4SLinus Torvalds }
861da177e4SLinus Torvalds
871da177e4SLinus Torvalds /**
881da177e4SLinus Torvalds * llc_sap_rtn_pdu - Informs upper layer on rx of an UI, XID or TEST pdu.
891da177e4SLinus Torvalds * @sap: pointer to SAP
901da177e4SLinus Torvalds * @skb: received pdu
911da177e4SLinus Torvalds */
llc_sap_rtn_pdu(struct llc_sap * sap,struct sk_buff * skb)921da177e4SLinus Torvalds void llc_sap_rtn_pdu(struct llc_sap *sap, struct sk_buff *skb)
931da177e4SLinus Torvalds {
941da177e4SLinus Torvalds struct llc_sap_state_ev *ev = llc_sap_ev(skb);
951da177e4SLinus Torvalds struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
961da177e4SLinus Torvalds
971da177e4SLinus Torvalds switch (LLC_U_PDU_RSP(pdu)) {
981da177e4SLinus Torvalds case LLC_1_PDU_CMD_TEST:
991da177e4SLinus Torvalds ev->prim = LLC_TEST_PRIM; break;
1001da177e4SLinus Torvalds case LLC_1_PDU_CMD_XID:
1011da177e4SLinus Torvalds ev->prim = LLC_XID_PRIM; break;
1021da177e4SLinus Torvalds case LLC_1_PDU_CMD_UI:
1031da177e4SLinus Torvalds ev->prim = LLC_DATAUNIT_PRIM; break;
1041da177e4SLinus Torvalds }
1051da177e4SLinus Torvalds ev->ind_cfm_flag = LLC_IND;
1061da177e4SLinus Torvalds }
1071da177e4SLinus Torvalds
1081da177e4SLinus Torvalds /**
1091da177e4SLinus Torvalds * llc_find_sap_trans - finds transition for event
1101da177e4SLinus Torvalds * @sap: pointer to SAP
1111da177e4SLinus Torvalds * @skb: happened event
1121da177e4SLinus Torvalds *
1131da177e4SLinus Torvalds * This function finds transition that matches with happened event.
1141da177e4SLinus Torvalds * Returns the pointer to found transition on success or %NULL for
1151da177e4SLinus Torvalds * failure.
1161da177e4SLinus Torvalds */
llc_find_sap_trans(struct llc_sap * sap,struct sk_buff * skb)1171da177e4SLinus Torvalds static struct llc_sap_state_trans *llc_find_sap_trans(struct llc_sap *sap,
1181da177e4SLinus Torvalds struct sk_buff *skb)
1191da177e4SLinus Torvalds {
1201da177e4SLinus Torvalds int i = 0;
1211da177e4SLinus Torvalds struct llc_sap_state_trans *rc = NULL;
1221da177e4SLinus Torvalds struct llc_sap_state_trans **next_trans;
1231da177e4SLinus Torvalds struct llc_sap_state *curr_state = &llc_sap_state_table[sap->state - 1];
1241da177e4SLinus Torvalds /*
1251da177e4SLinus Torvalds * Search thru events for this state until list exhausted or until
1261da177e4SLinus Torvalds * its obvious the event is not valid for the current state
1271da177e4SLinus Torvalds */
1281da177e4SLinus Torvalds for (next_trans = curr_state->transitions; next_trans[i]->ev; i++)
1291da177e4SLinus Torvalds if (!next_trans[i]->ev(sap, skb)) {
1301da177e4SLinus Torvalds rc = next_trans[i]; /* got event match; return it */
1311da177e4SLinus Torvalds break;
1321da177e4SLinus Torvalds }
1331da177e4SLinus Torvalds return rc;
1341da177e4SLinus Torvalds }
1351da177e4SLinus Torvalds
1361da177e4SLinus Torvalds /**
1371da177e4SLinus Torvalds * llc_exec_sap_trans_actions - execute actions related to event
1381da177e4SLinus Torvalds * @sap: pointer to SAP
1391da177e4SLinus Torvalds * @trans: pointer to transition that it's actions must be performed
1401da177e4SLinus Torvalds * @skb: happened event.
1411da177e4SLinus Torvalds *
1421da177e4SLinus Torvalds * This function executes actions that is related to happened event.
1431da177e4SLinus Torvalds * Returns 0 for success and 1 for failure of at least one action.
1441da177e4SLinus Torvalds */
llc_exec_sap_trans_actions(struct llc_sap * sap,struct llc_sap_state_trans * trans,struct sk_buff * skb)1451da177e4SLinus Torvalds static int llc_exec_sap_trans_actions(struct llc_sap *sap,
1461da177e4SLinus Torvalds struct llc_sap_state_trans *trans,
1471da177e4SLinus Torvalds struct sk_buff *skb)
1481da177e4SLinus Torvalds {
1491da177e4SLinus Torvalds int rc = 0;
15022bbf5f3SJoe Perches const llc_sap_action_t *next_action = trans->ev_actions;
1511da177e4SLinus Torvalds
1521da177e4SLinus Torvalds for (; next_action && *next_action; next_action++)
1531da177e4SLinus Torvalds if ((*next_action)(sap, skb))
1541da177e4SLinus Torvalds rc = 1;
1551da177e4SLinus Torvalds return rc;
1561da177e4SLinus Torvalds }
1571da177e4SLinus Torvalds
1581da177e4SLinus Torvalds /**
1591da177e4SLinus Torvalds * llc_sap_next_state - finds transition, execs actions & change SAP state
1601da177e4SLinus Torvalds * @sap: pointer to SAP
1611da177e4SLinus Torvalds * @skb: happened event
1621da177e4SLinus Torvalds *
1631da177e4SLinus Torvalds * This function finds transition that matches with happened event, then
1641da177e4SLinus Torvalds * executes related actions and finally changes state of SAP. It returns
1651da177e4SLinus Torvalds * 0 on success and 1 for failure.
1661da177e4SLinus Torvalds */
llc_sap_next_state(struct llc_sap * sap,struct sk_buff * skb)1671da177e4SLinus Torvalds static int llc_sap_next_state(struct llc_sap *sap, struct sk_buff *skb)
1681da177e4SLinus Torvalds {
1691da177e4SLinus Torvalds int rc = 1;
1701da177e4SLinus Torvalds struct llc_sap_state_trans *trans;
1711da177e4SLinus Torvalds
1721da177e4SLinus Torvalds if (sap->state > LLC_NR_SAP_STATES)
1731da177e4SLinus Torvalds goto out;
1741da177e4SLinus Torvalds trans = llc_find_sap_trans(sap, skb);
1751da177e4SLinus Torvalds if (!trans)
1761da177e4SLinus Torvalds goto out;
1771da177e4SLinus Torvalds /*
1781da177e4SLinus Torvalds * Got the state to which we next transition; perform the actions
1791da177e4SLinus Torvalds * associated with this transition before actually transitioning to the
1801da177e4SLinus Torvalds * next state
1811da177e4SLinus Torvalds */
1821da177e4SLinus Torvalds rc = llc_exec_sap_trans_actions(sap, trans, skb);
1831da177e4SLinus Torvalds if (rc)
1841da177e4SLinus Torvalds goto out;
1851da177e4SLinus Torvalds /*
1861da177e4SLinus Torvalds * Transition SAP to next state if all actions execute successfully
1871da177e4SLinus Torvalds */
1881da177e4SLinus Torvalds sap->state = trans->next_state;
1891da177e4SLinus Torvalds out:
1901da177e4SLinus Torvalds return rc;
1911da177e4SLinus Torvalds }
1921da177e4SLinus Torvalds
1931da177e4SLinus Torvalds /**
1941da177e4SLinus Torvalds * llc_sap_state_process - sends event to SAP state machine
1951da177e4SLinus Torvalds * @sap: sap to use
1961da177e4SLinus Torvalds * @skb: pointer to occurred event
1971da177e4SLinus Torvalds *
1981da177e4SLinus Torvalds * After executing actions of the event, upper layer will be indicated
1991da177e4SLinus Torvalds * if needed(on receiving an UI frame). sk can be null for the
2001da177e4SLinus Torvalds * datalink_proto case.
201c6ee11c3SEric Biggers *
202c6ee11c3SEric Biggers * This function always consumes a reference to the skb.
2031da177e4SLinus Torvalds */
llc_sap_state_process(struct llc_sap * sap,struct sk_buff * skb)2041da177e4SLinus Torvalds static void llc_sap_state_process(struct llc_sap *sap, struct sk_buff *skb)
2051da177e4SLinus Torvalds {
2061da177e4SLinus Torvalds struct llc_sap_state_ev *ev = llc_sap_ev(skb);
2071da177e4SLinus Torvalds
2081da177e4SLinus Torvalds ev->ind_cfm_flag = 0;
2091da177e4SLinus Torvalds llc_sap_next_state(sap, skb);
210c6ee11c3SEric Biggers
211c6ee11c3SEric Biggers if (ev->ind_cfm_flag == LLC_IND && skb->sk->sk_state != TCP_LISTEN) {
21204e4223fSArnaldo Carvalho de Melo llc_save_primitive(skb->sk, skb, ev->prim);
2131da177e4SLinus Torvalds
2141da177e4SLinus Torvalds /* queue skb to the user. */
215c6ee11c3SEric Biggers if (sock_queue_rcv_skb(skb->sk, skb) == 0)
216c6ee11c3SEric Biggers return;
2171da177e4SLinus Torvalds }
2181da177e4SLinus Torvalds kfree_skb(skb);
2191da177e4SLinus Torvalds }
2201da177e4SLinus Torvalds
2211da177e4SLinus Torvalds /**
2221da177e4SLinus Torvalds * llc_build_and_send_test_pkt - TEST interface for upper layers.
2231da177e4SLinus Torvalds * @sap: sap to use
2241da177e4SLinus Torvalds * @skb: packet to send
2251da177e4SLinus Torvalds * @dmac: destination mac address
2261da177e4SLinus Torvalds * @dsap: destination sap
2271da177e4SLinus Torvalds *
2281da177e4SLinus Torvalds * This function is called when upper layer wants to send a TEST pdu.
2291da177e4SLinus Torvalds * Returns 0 for success, 1 otherwise.
2301da177e4SLinus Torvalds */
llc_build_and_send_test_pkt(struct llc_sap * sap,struct sk_buff * skb,u8 * dmac,u8 dsap)2311da177e4SLinus Torvalds void llc_build_and_send_test_pkt(struct llc_sap *sap,
2321da177e4SLinus Torvalds struct sk_buff *skb, u8 *dmac, u8 dsap)
2331da177e4SLinus Torvalds {
2341da177e4SLinus Torvalds struct llc_sap_state_ev *ev = llc_sap_ev(skb);
2351da177e4SLinus Torvalds
2361da177e4SLinus Torvalds ev->saddr.lsap = sap->laddr.lsap;
2371da177e4SLinus Torvalds ev->daddr.lsap = dsap;
2381da177e4SLinus Torvalds memcpy(ev->saddr.mac, skb->dev->dev_addr, IFHWADDRLEN);
2391da177e4SLinus Torvalds memcpy(ev->daddr.mac, dmac, IFHWADDRLEN);
2401da177e4SLinus Torvalds
2411da177e4SLinus Torvalds ev->type = LLC_SAP_EV_TYPE_PRIM;
2421da177e4SLinus Torvalds ev->prim = LLC_TEST_PRIM;
2431da177e4SLinus Torvalds ev->prim_type = LLC_PRIM_TYPE_REQ;
2441da177e4SLinus Torvalds llc_sap_state_process(sap, skb);
2451da177e4SLinus Torvalds }
2461da177e4SLinus Torvalds
2471da177e4SLinus Torvalds /**
2481da177e4SLinus Torvalds * llc_build_and_send_xid_pkt - XID interface for upper layers
2491da177e4SLinus Torvalds * @sap: sap to use
2501da177e4SLinus Torvalds * @skb: packet to send
2511da177e4SLinus Torvalds * @dmac: destination mac address
2521da177e4SLinus Torvalds * @dsap: destination sap
2531da177e4SLinus Torvalds *
2541da177e4SLinus Torvalds * This function is called when upper layer wants to send a XID pdu.
2551da177e4SLinus Torvalds * Returns 0 for success, 1 otherwise.
2561da177e4SLinus Torvalds */
llc_build_and_send_xid_pkt(struct llc_sap * sap,struct sk_buff * skb,u8 * dmac,u8 dsap)2571da177e4SLinus Torvalds void llc_build_and_send_xid_pkt(struct llc_sap *sap, struct sk_buff *skb,
2581da177e4SLinus Torvalds u8 *dmac, u8 dsap)
2591da177e4SLinus Torvalds {
2601da177e4SLinus Torvalds struct llc_sap_state_ev *ev = llc_sap_ev(skb);
2611da177e4SLinus Torvalds
2621da177e4SLinus Torvalds ev->saddr.lsap = sap->laddr.lsap;
2631da177e4SLinus Torvalds ev->daddr.lsap = dsap;
2641da177e4SLinus Torvalds memcpy(ev->saddr.mac, skb->dev->dev_addr, IFHWADDRLEN);
2651da177e4SLinus Torvalds memcpy(ev->daddr.mac, dmac, IFHWADDRLEN);
2661da177e4SLinus Torvalds
2671da177e4SLinus Torvalds ev->type = LLC_SAP_EV_TYPE_PRIM;
2681da177e4SLinus Torvalds ev->prim = LLC_XID_PRIM;
2691da177e4SLinus Torvalds ev->prim_type = LLC_PRIM_TYPE_REQ;
2701da177e4SLinus Torvalds llc_sap_state_process(sap, skb);
2711da177e4SLinus Torvalds }
2721da177e4SLinus Torvalds
2731da177e4SLinus Torvalds /**
2741da177e4SLinus Torvalds * llc_sap_rcv - sends received pdus to the sap state machine
2751da177e4SLinus Torvalds * @sap: current sap component structure.
2761da177e4SLinus Torvalds * @skb: received frame.
27774c950c9SAndrew Lunn * @sk: socket to associate to frame
2781da177e4SLinus Torvalds *
2791da177e4SLinus Torvalds * Sends received pdus to the sap state machine.
2801da177e4SLinus Torvalds */
llc_sap_rcv(struct llc_sap * sap,struct sk_buff * skb,struct sock * sk)2813446b9d5SArnaldo Carvalho de Melo static void llc_sap_rcv(struct llc_sap *sap, struct sk_buff *skb,
2823446b9d5SArnaldo Carvalho de Melo struct sock *sk)
2831da177e4SLinus Torvalds {
2841da177e4SLinus Torvalds struct llc_sap_state_ev *ev = llc_sap_ev(skb);
2851da177e4SLinus Torvalds
2861da177e4SLinus Torvalds ev->type = LLC_SAP_EV_TYPE_PDU;
2871da177e4SLinus Torvalds ev->reason = 0;
2888b74d439SEric Dumazet skb_orphan(skb);
2898b74d439SEric Dumazet sock_hold(sk);
2903446b9d5SArnaldo Carvalho de Melo skb->sk = sk;
2918b74d439SEric Dumazet skb->destructor = sock_efree;
2921da177e4SLinus Torvalds llc_sap_state_process(sap, skb);
2931da177e4SLinus Torvalds }
2941da177e4SLinus Torvalds
llc_dgram_match(const struct llc_sap * sap,const struct llc_addr * laddr,const struct sock * sk,const struct net * net)295b76f5a84SOctavian Purdila static inline bool llc_dgram_match(const struct llc_sap *sap,
296b76f5a84SOctavian Purdila const struct llc_addr *laddr,
297*9b64e93eSKuniyuki Iwashima const struct sock *sk,
298*9b64e93eSKuniyuki Iwashima const struct net *net)
299b76f5a84SOctavian Purdila {
300b76f5a84SOctavian Purdila struct llc_sock *llc = llc_sk(sk);
301b76f5a84SOctavian Purdila
302b76f5a84SOctavian Purdila return sk->sk_type == SOCK_DGRAM &&
303*9b64e93eSKuniyuki Iwashima net_eq(sock_net(sk), net) &&
304b76f5a84SOctavian Purdila llc->laddr.lsap == laddr->lsap &&
305951fd874SJoe Perches ether_addr_equal(llc->laddr.mac, laddr->mac);
306b76f5a84SOctavian Purdila }
307b76f5a84SOctavian Purdila
3081da177e4SLinus Torvalds /**
3091da177e4SLinus Torvalds * llc_lookup_dgram - Finds dgram socket for the local sap/mac
3101da177e4SLinus Torvalds * @sap: SAP
3111da177e4SLinus Torvalds * @laddr: address of local LLC (MAC + SAP)
312*9b64e93eSKuniyuki Iwashima * @net: netns to look up a socket in
3131da177e4SLinus Torvalds *
3141da177e4SLinus Torvalds * Search socket list of the SAP and finds connection using the local
3151da177e4SLinus Torvalds * mac, and local sap. Returns pointer for socket found, %NULL otherwise.
3161da177e4SLinus Torvalds */
llc_lookup_dgram(struct llc_sap * sap,const struct llc_addr * laddr,const struct net * net)3171da177e4SLinus Torvalds static struct sock *llc_lookup_dgram(struct llc_sap *sap,
318*9b64e93eSKuniyuki Iwashima const struct llc_addr *laddr,
319*9b64e93eSKuniyuki Iwashima const struct net *net)
3201da177e4SLinus Torvalds {
3211da177e4SLinus Torvalds struct sock *rc;
322b76f5a84SOctavian Purdila struct hlist_nulls_node *node;
32352d58aefSOctavian Purdila int slot = llc_sk_laddr_hashfn(sap, laddr);
32452d58aefSOctavian Purdila struct hlist_nulls_head *laddr_hb = &sap->sk_laddr_hash[slot];
3251da177e4SLinus Torvalds
326b76f5a84SOctavian Purdila rcu_read_lock_bh();
327b76f5a84SOctavian Purdila again:
32852d58aefSOctavian Purdila sk_nulls_for_each_rcu(rc, node, laddr_hb) {
329*9b64e93eSKuniyuki Iwashima if (llc_dgram_match(sap, laddr, rc, net)) {
3305f0d5a3aSPaul E. McKenney /* Extra checks required by SLAB_TYPESAFE_BY_RCU */
33141c6d650SReshetova, Elena if (unlikely(!refcount_inc_not_zero(&rc->sk_refcnt)))
332b76f5a84SOctavian Purdila goto again;
333b76f5a84SOctavian Purdila if (unlikely(llc_sk(rc)->sap != sap ||
334*9b64e93eSKuniyuki Iwashima !llc_dgram_match(sap, laddr, rc, net))) {
335b76f5a84SOctavian Purdila sock_put(rc);
336b76f5a84SOctavian Purdila continue;
337b76f5a84SOctavian Purdila }
3381da177e4SLinus Torvalds goto found;
3391da177e4SLinus Torvalds }
3401da177e4SLinus Torvalds }
3411da177e4SLinus Torvalds rc = NULL;
34252d58aefSOctavian Purdila /*
34352d58aefSOctavian Purdila * if the nulls value we got at the end of this lookup is
34452d58aefSOctavian Purdila * not the expected one, we must restart lookup.
34552d58aefSOctavian Purdila * We probably met an item that was moved to another chain.
34652d58aefSOctavian Purdila */
34752d58aefSOctavian Purdila if (unlikely(get_nulls_value(node) != slot))
34852d58aefSOctavian Purdila goto again;
3491da177e4SLinus Torvalds found:
350b76f5a84SOctavian Purdila rcu_read_unlock_bh();
3511da177e4SLinus Torvalds return rc;
3521da177e4SLinus Torvalds }
3531da177e4SLinus Torvalds
llc_mcast_match(const struct llc_sap * sap,const struct llc_addr * laddr,const struct sk_buff * skb,const struct sock * sk)354b76f5a84SOctavian Purdila static inline bool llc_mcast_match(const struct llc_sap *sap,
355b76f5a84SOctavian Purdila const struct llc_addr *laddr,
356b76f5a84SOctavian Purdila const struct sk_buff *skb,
357b76f5a84SOctavian Purdila const struct sock *sk)
358b76f5a84SOctavian Purdila {
359b76f5a84SOctavian Purdila struct llc_sock *llc = llc_sk(sk);
360b76f5a84SOctavian Purdila
361b76f5a84SOctavian Purdila return sk->sk_type == SOCK_DGRAM &&
362b76f5a84SOctavian Purdila llc->laddr.lsap == laddr->lsap &&
363b76f5a84SOctavian Purdila llc->dev == skb->dev;
364b76f5a84SOctavian Purdila }
365b76f5a84SOctavian Purdila
llc_do_mcast(struct llc_sap * sap,struct sk_buff * skb,struct sock ** stack,int count)3660f7b67ddSOctavian Purdila static void llc_do_mcast(struct llc_sap *sap, struct sk_buff *skb,
3670f7b67ddSOctavian Purdila struct sock **stack, int count)
3680f7b67ddSOctavian Purdila {
3690f7b67ddSOctavian Purdila struct sk_buff *skb1;
3700f7b67ddSOctavian Purdila int i;
3710f7b67ddSOctavian Purdila
3720f7b67ddSOctavian Purdila for (i = 0; i < count; i++) {
3730f7b67ddSOctavian Purdila skb1 = skb_clone(skb, GFP_ATOMIC);
3740f7b67ddSOctavian Purdila if (!skb1) {
3750f7b67ddSOctavian Purdila sock_put(stack[i]);
3760f7b67ddSOctavian Purdila continue;
3770f7b67ddSOctavian Purdila }
3780f7b67ddSOctavian Purdila
3790f7b67ddSOctavian Purdila llc_sap_rcv(sap, skb1, stack[i]);
3800f7b67ddSOctavian Purdila sock_put(stack[i]);
3810f7b67ddSOctavian Purdila }
3820f7b67ddSOctavian Purdila }
3830f7b67ddSOctavian Purdila
384bc0e6467SStephen Hemminger /**
385bc0e6467SStephen Hemminger * llc_sap_mcast - Deliver multicast PDU's to all matching datagram sockets.
386bc0e6467SStephen Hemminger * @sap: SAP
387bc0e6467SStephen Hemminger * @laddr: address of local LLC (MAC + SAP)
38874c950c9SAndrew Lunn * @skb: PDU to deliver
389bc0e6467SStephen Hemminger *
390bc0e6467SStephen Hemminger * Search socket list of the SAP and finds connections with same sap.
391bc0e6467SStephen Hemminger * Deliver clone to each.
392bc0e6467SStephen Hemminger */
llc_sap_mcast(struct llc_sap * sap,const struct llc_addr * laddr,struct sk_buff * skb)393bc0e6467SStephen Hemminger static void llc_sap_mcast(struct llc_sap *sap,
394bc0e6467SStephen Hemminger const struct llc_addr *laddr,
395bc0e6467SStephen Hemminger struct sk_buff *skb)
396bc0e6467SStephen Hemminger {
397678f4bdaSSalvatore Mesoraca int i = 0;
398678f4bdaSSalvatore Mesoraca struct sock *sk;
399678f4bdaSSalvatore Mesoraca struct sock *stack[256 / sizeof(struct sock *)];
4006d2e3ea2SOctavian Purdila struct llc_sock *llc;
4016d2e3ea2SOctavian Purdila struct hlist_head *dev_hb = llc_sk_dev_hash(sap, skb->dev->ifindex);
402bc0e6467SStephen Hemminger
403b76f5a84SOctavian Purdila spin_lock_bh(&sap->sk_lock);
404b67bfe0dSSasha Levin hlist_for_each_entry(llc, dev_hb, dev_hash_node) {
4056d2e3ea2SOctavian Purdila
4066d2e3ea2SOctavian Purdila sk = &llc->sk;
407bc0e6467SStephen Hemminger
408b76f5a84SOctavian Purdila if (!llc_mcast_match(sap, laddr, skb, sk))
4097ee66fcbSStephen Hemminger continue;
4107ee66fcbSStephen Hemminger
411bc0e6467SStephen Hemminger sock_hold(sk);
412678f4bdaSSalvatore Mesoraca if (i < ARRAY_SIZE(stack))
4130f7b67ddSOctavian Purdila stack[i++] = sk;
4140f7b67ddSOctavian Purdila else {
4150f7b67ddSOctavian Purdila llc_do_mcast(sap, skb, stack, i);
4160f7b67ddSOctavian Purdila i = 0;
4170f7b67ddSOctavian Purdila }
418bc0e6467SStephen Hemminger }
419b76f5a84SOctavian Purdila spin_unlock_bh(&sap->sk_lock);
4200f7b67ddSOctavian Purdila
4210f7b67ddSOctavian Purdila llc_do_mcast(sap, skb, stack, i);
422bc0e6467SStephen Hemminger }
423bc0e6467SStephen Hemminger
424bc0e6467SStephen Hemminger
llc_sap_handler(struct llc_sap * sap,struct sk_buff * skb)4251da177e4SLinus Torvalds void llc_sap_handler(struct llc_sap *sap, struct sk_buff *skb)
4261da177e4SLinus Torvalds {
4271da177e4SLinus Torvalds struct llc_addr laddr;
4281da177e4SLinus Torvalds
4291da177e4SLinus Torvalds llc_pdu_decode_da(skb, laddr.mac);
4301da177e4SLinus Torvalds llc_pdu_decode_dsap(skb, &laddr.lsap);
4311da177e4SLinus Torvalds
432951fd874SJoe Perches if (is_multicast_ether_addr(laddr.mac)) {
433bc0e6467SStephen Hemminger llc_sap_mcast(sap, &laddr, skb);
434bc0e6467SStephen Hemminger kfree_skb(skb);
435bc0e6467SStephen Hemminger } else {
436*9b64e93eSKuniyuki Iwashima struct sock *sk = llc_lookup_dgram(sap, &laddr, dev_net(skb->dev));
4371da177e4SLinus Torvalds if (sk) {
4383446b9d5SArnaldo Carvalho de Melo llc_sap_rcv(sap, skb, sk);
4391da177e4SLinus Torvalds sock_put(sk);
4401da177e4SLinus Torvalds } else
4411da177e4SLinus Torvalds kfree_skb(skb);
4421da177e4SLinus Torvalds }
443bc0e6467SStephen Hemminger }
444