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> 261da177e4SLinus Torvalds 271da177e4SLinus Torvalds /** 281da177e4SLinus Torvalds * llc_alloc_frame - allocates sk_buff for frame 291d67e650SArnaldo Carvalho de Melo * @dev: network device this skb will be sent over 301da177e4SLinus Torvalds * 311da177e4SLinus Torvalds * Allocates an sk_buff for frame and initializes sk_buff fields. 321da177e4SLinus Torvalds * Returns allocated skb or %NULL when out of memory. 331da177e4SLinus Torvalds */ 341d67e650SArnaldo Carvalho de Melo struct sk_buff *llc_alloc_frame(struct net_device *dev) 351da177e4SLinus Torvalds { 361da177e4SLinus Torvalds struct sk_buff *skb = alloc_skb(128, GFP_ATOMIC); 371da177e4SLinus Torvalds 381da177e4SLinus Torvalds if (skb) { 391da177e4SLinus Torvalds skb_reserve(skb, 50); 401da177e4SLinus Torvalds skb->nh.raw = skb->h.raw = skb->data; 411da177e4SLinus Torvalds skb->protocol = htons(ETH_P_802_2); 421d67e650SArnaldo Carvalho de Melo skb->dev = dev; 431da177e4SLinus Torvalds skb->mac.raw = skb->head; 441da177e4SLinus Torvalds } 451da177e4SLinus Torvalds return skb; 461da177e4SLinus Torvalds } 471da177e4SLinus Torvalds 481da177e4SLinus Torvalds void llc_save_primitive(struct sk_buff* skb, u8 prim) 491da177e4SLinus Torvalds { 501da177e4SLinus Torvalds struct sockaddr_llc *addr = llc_ui_skb_cb(skb); 511da177e4SLinus Torvalds 521da177e4SLinus Torvalds /* save primitive for use by the user. */ 531da177e4SLinus Torvalds addr->sllc_family = skb->sk->sk_family; 541da177e4SLinus Torvalds addr->sllc_arphrd = skb->dev->type; 551da177e4SLinus Torvalds addr->sllc_test = prim == LLC_TEST_PRIM; 561da177e4SLinus Torvalds addr->sllc_xid = prim == LLC_XID_PRIM; 571da177e4SLinus Torvalds addr->sllc_ua = prim == LLC_DATAUNIT_PRIM; 581da177e4SLinus Torvalds llc_pdu_decode_sa(skb, addr->sllc_mac); 591da177e4SLinus Torvalds llc_pdu_decode_ssap(skb, &addr->sllc_sap); 601da177e4SLinus Torvalds } 611da177e4SLinus Torvalds 621da177e4SLinus Torvalds /** 631da177e4SLinus Torvalds * llc_sap_rtn_pdu - Informs upper layer on rx of an UI, XID or TEST pdu. 641da177e4SLinus Torvalds * @sap: pointer to SAP 651da177e4SLinus Torvalds * @skb: received pdu 661da177e4SLinus Torvalds */ 671da177e4SLinus Torvalds void llc_sap_rtn_pdu(struct llc_sap *sap, struct sk_buff *skb) 681da177e4SLinus Torvalds { 691da177e4SLinus Torvalds struct llc_sap_state_ev *ev = llc_sap_ev(skb); 701da177e4SLinus Torvalds struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb); 711da177e4SLinus Torvalds 721da177e4SLinus Torvalds switch (LLC_U_PDU_RSP(pdu)) { 731da177e4SLinus Torvalds case LLC_1_PDU_CMD_TEST: 741da177e4SLinus Torvalds ev->prim = LLC_TEST_PRIM; break; 751da177e4SLinus Torvalds case LLC_1_PDU_CMD_XID: 761da177e4SLinus Torvalds ev->prim = LLC_XID_PRIM; break; 771da177e4SLinus Torvalds case LLC_1_PDU_CMD_UI: 781da177e4SLinus Torvalds ev->prim = LLC_DATAUNIT_PRIM; break; 791da177e4SLinus Torvalds } 801da177e4SLinus Torvalds ev->ind_cfm_flag = LLC_IND; 811da177e4SLinus Torvalds } 821da177e4SLinus Torvalds 831da177e4SLinus Torvalds /** 841da177e4SLinus Torvalds * llc_find_sap_trans - finds transition for event 851da177e4SLinus Torvalds * @sap: pointer to SAP 861da177e4SLinus Torvalds * @skb: happened event 871da177e4SLinus Torvalds * 881da177e4SLinus Torvalds * This function finds transition that matches with happened event. 891da177e4SLinus Torvalds * Returns the pointer to found transition on success or %NULL for 901da177e4SLinus Torvalds * failure. 911da177e4SLinus Torvalds */ 921da177e4SLinus Torvalds static struct llc_sap_state_trans *llc_find_sap_trans(struct llc_sap *sap, 931da177e4SLinus Torvalds struct sk_buff* skb) 941da177e4SLinus Torvalds { 951da177e4SLinus Torvalds int i = 0; 961da177e4SLinus Torvalds struct llc_sap_state_trans *rc = NULL; 971da177e4SLinus Torvalds struct llc_sap_state_trans **next_trans; 981da177e4SLinus Torvalds struct llc_sap_state *curr_state = &llc_sap_state_table[sap->state - 1]; 991da177e4SLinus Torvalds /* 1001da177e4SLinus Torvalds * Search thru events for this state until list exhausted or until 1011da177e4SLinus Torvalds * its obvious the event is not valid for the current state 1021da177e4SLinus Torvalds */ 1031da177e4SLinus Torvalds for (next_trans = curr_state->transitions; next_trans[i]->ev; i++) 1041da177e4SLinus Torvalds if (!next_trans[i]->ev(sap, skb)) { 1051da177e4SLinus Torvalds rc = next_trans[i]; /* got event match; return it */ 1061da177e4SLinus Torvalds break; 1071da177e4SLinus Torvalds } 1081da177e4SLinus Torvalds return rc; 1091da177e4SLinus Torvalds } 1101da177e4SLinus Torvalds 1111da177e4SLinus Torvalds /** 1121da177e4SLinus Torvalds * llc_exec_sap_trans_actions - execute actions related to event 1131da177e4SLinus Torvalds * @sap: pointer to SAP 1141da177e4SLinus Torvalds * @trans: pointer to transition that it's actions must be performed 1151da177e4SLinus Torvalds * @skb: happened event. 1161da177e4SLinus Torvalds * 1171da177e4SLinus Torvalds * This function executes actions that is related to happened event. 1181da177e4SLinus Torvalds * Returns 0 for success and 1 for failure of at least one action. 1191da177e4SLinus Torvalds */ 1201da177e4SLinus Torvalds static int llc_exec_sap_trans_actions(struct llc_sap *sap, 1211da177e4SLinus Torvalds struct llc_sap_state_trans *trans, 1221da177e4SLinus Torvalds struct sk_buff *skb) 1231da177e4SLinus Torvalds { 1241da177e4SLinus Torvalds int rc = 0; 1251da177e4SLinus Torvalds llc_sap_action_t *next_action = trans->ev_actions; 1261da177e4SLinus Torvalds 1271da177e4SLinus Torvalds for (; next_action && *next_action; next_action++) 1281da177e4SLinus Torvalds if ((*next_action)(sap, skb)) 1291da177e4SLinus Torvalds rc = 1; 1301da177e4SLinus Torvalds return rc; 1311da177e4SLinus Torvalds } 1321da177e4SLinus Torvalds 1331da177e4SLinus Torvalds /** 1341da177e4SLinus Torvalds * llc_sap_next_state - finds transition, execs actions & change SAP state 1351da177e4SLinus Torvalds * @sap: pointer to SAP 1361da177e4SLinus Torvalds * @skb: happened event 1371da177e4SLinus Torvalds * 1381da177e4SLinus Torvalds * This function finds transition that matches with happened event, then 1391da177e4SLinus Torvalds * executes related actions and finally changes state of SAP. It returns 1401da177e4SLinus Torvalds * 0 on success and 1 for failure. 1411da177e4SLinus Torvalds */ 1421da177e4SLinus Torvalds static int llc_sap_next_state(struct llc_sap *sap, struct sk_buff *skb) 1431da177e4SLinus Torvalds { 1441da177e4SLinus Torvalds int rc = 1; 1451da177e4SLinus Torvalds struct llc_sap_state_trans *trans; 1461da177e4SLinus Torvalds 1471da177e4SLinus Torvalds if (sap->state > LLC_NR_SAP_STATES) 1481da177e4SLinus Torvalds goto out; 1491da177e4SLinus Torvalds trans = llc_find_sap_trans(sap, skb); 1501da177e4SLinus Torvalds if (!trans) 1511da177e4SLinus Torvalds goto out; 1521da177e4SLinus Torvalds /* 1531da177e4SLinus Torvalds * Got the state to which we next transition; perform the actions 1541da177e4SLinus Torvalds * associated with this transition before actually transitioning to the 1551da177e4SLinus Torvalds * next state 1561da177e4SLinus Torvalds */ 1571da177e4SLinus Torvalds rc = llc_exec_sap_trans_actions(sap, trans, skb); 1581da177e4SLinus Torvalds if (rc) 1591da177e4SLinus Torvalds goto out; 1601da177e4SLinus Torvalds /* 1611da177e4SLinus Torvalds * Transition SAP to next state if all actions execute successfully 1621da177e4SLinus Torvalds */ 1631da177e4SLinus Torvalds sap->state = trans->next_state; 1641da177e4SLinus Torvalds out: 1651da177e4SLinus Torvalds return rc; 1661da177e4SLinus Torvalds } 1671da177e4SLinus Torvalds 1681da177e4SLinus Torvalds /** 1691da177e4SLinus Torvalds * llc_sap_state_process - sends event to SAP state machine 1701da177e4SLinus Torvalds * @sap: sap to use 1711da177e4SLinus Torvalds * @skb: pointer to occurred event 1721da177e4SLinus Torvalds * 1731da177e4SLinus Torvalds * After executing actions of the event, upper layer will be indicated 1741da177e4SLinus Torvalds * if needed(on receiving an UI frame). sk can be null for the 1751da177e4SLinus Torvalds * datalink_proto case. 1761da177e4SLinus Torvalds */ 1771da177e4SLinus Torvalds static void llc_sap_state_process(struct llc_sap *sap, struct sk_buff *skb) 1781da177e4SLinus Torvalds { 1791da177e4SLinus Torvalds struct llc_sap_state_ev *ev = llc_sap_ev(skb); 1801da177e4SLinus Torvalds 1811da177e4SLinus Torvalds /* 1821da177e4SLinus Torvalds * We have to hold the skb, because llc_sap_next_state 1831da177e4SLinus Torvalds * will kfree it in the sending path and we need to 1841da177e4SLinus Torvalds * look at the skb->cb, where we encode llc_sap_state_ev. 1851da177e4SLinus Torvalds */ 1861da177e4SLinus Torvalds skb_get(skb); 1871da177e4SLinus Torvalds ev->ind_cfm_flag = 0; 1881da177e4SLinus Torvalds llc_sap_next_state(sap, skb); 1891da177e4SLinus Torvalds if (ev->ind_cfm_flag == LLC_IND) { 1901da177e4SLinus Torvalds if (skb->sk->sk_state == TCP_LISTEN) 1911da177e4SLinus Torvalds kfree_skb(skb); 1921da177e4SLinus Torvalds else { 1931da177e4SLinus Torvalds llc_save_primitive(skb, ev->prim); 1941da177e4SLinus Torvalds 1951da177e4SLinus Torvalds /* queue skb to the user. */ 1961da177e4SLinus Torvalds if (sock_queue_rcv_skb(skb->sk, skb)) 1971da177e4SLinus Torvalds kfree_skb(skb); 1981da177e4SLinus Torvalds } 1991da177e4SLinus Torvalds } 2001da177e4SLinus Torvalds kfree_skb(skb); 2011da177e4SLinus Torvalds } 2021da177e4SLinus Torvalds 2031da177e4SLinus Torvalds /** 2041da177e4SLinus Torvalds * llc_build_and_send_test_pkt - TEST interface for upper layers. 2051da177e4SLinus Torvalds * @sap: sap to use 2061da177e4SLinus Torvalds * @skb: packet to send 2071da177e4SLinus Torvalds * @dmac: destination mac address 2081da177e4SLinus Torvalds * @dsap: destination sap 2091da177e4SLinus Torvalds * 2101da177e4SLinus Torvalds * This function is called when upper layer wants to send a TEST pdu. 2111da177e4SLinus Torvalds * Returns 0 for success, 1 otherwise. 2121da177e4SLinus Torvalds */ 2131da177e4SLinus Torvalds void llc_build_and_send_test_pkt(struct llc_sap *sap, 2141da177e4SLinus Torvalds struct sk_buff *skb, u8 *dmac, u8 dsap) 2151da177e4SLinus Torvalds { 2161da177e4SLinus Torvalds struct llc_sap_state_ev *ev = llc_sap_ev(skb); 2171da177e4SLinus Torvalds 2181da177e4SLinus Torvalds ev->saddr.lsap = sap->laddr.lsap; 2191da177e4SLinus Torvalds ev->daddr.lsap = dsap; 2201da177e4SLinus Torvalds memcpy(ev->saddr.mac, skb->dev->dev_addr, IFHWADDRLEN); 2211da177e4SLinus Torvalds memcpy(ev->daddr.mac, dmac, IFHWADDRLEN); 2221da177e4SLinus Torvalds 2231da177e4SLinus Torvalds ev->type = LLC_SAP_EV_TYPE_PRIM; 2241da177e4SLinus Torvalds ev->prim = LLC_TEST_PRIM; 2251da177e4SLinus Torvalds ev->prim_type = LLC_PRIM_TYPE_REQ; 2261da177e4SLinus Torvalds llc_sap_state_process(sap, skb); 2271da177e4SLinus Torvalds } 2281da177e4SLinus Torvalds 2291da177e4SLinus Torvalds /** 2301da177e4SLinus Torvalds * llc_build_and_send_xid_pkt - XID interface for upper layers 2311da177e4SLinus Torvalds * @sap: sap to use 2321da177e4SLinus Torvalds * @skb: packet to send 2331da177e4SLinus Torvalds * @dmac: destination mac address 2341da177e4SLinus Torvalds * @dsap: destination sap 2351da177e4SLinus Torvalds * 2361da177e4SLinus Torvalds * This function is called when upper layer wants to send a XID pdu. 2371da177e4SLinus Torvalds * Returns 0 for success, 1 otherwise. 2381da177e4SLinus Torvalds */ 2391da177e4SLinus Torvalds void llc_build_and_send_xid_pkt(struct llc_sap *sap, struct sk_buff *skb, 2401da177e4SLinus Torvalds u8 *dmac, u8 dsap) 2411da177e4SLinus Torvalds { 2421da177e4SLinus Torvalds struct llc_sap_state_ev *ev = llc_sap_ev(skb); 2431da177e4SLinus Torvalds 2441da177e4SLinus Torvalds ev->saddr.lsap = sap->laddr.lsap; 2451da177e4SLinus Torvalds ev->daddr.lsap = dsap; 2461da177e4SLinus Torvalds memcpy(ev->saddr.mac, skb->dev->dev_addr, IFHWADDRLEN); 2471da177e4SLinus Torvalds memcpy(ev->daddr.mac, dmac, IFHWADDRLEN); 2481da177e4SLinus Torvalds 2491da177e4SLinus Torvalds ev->type = LLC_SAP_EV_TYPE_PRIM; 2501da177e4SLinus Torvalds ev->prim = LLC_XID_PRIM; 2511da177e4SLinus Torvalds ev->prim_type = LLC_PRIM_TYPE_REQ; 2521da177e4SLinus Torvalds llc_sap_state_process(sap, skb); 2531da177e4SLinus Torvalds } 2541da177e4SLinus Torvalds 2551da177e4SLinus Torvalds /** 2561da177e4SLinus Torvalds * llc_sap_rcv - sends received pdus to the sap state machine 2571da177e4SLinus Torvalds * @sap: current sap component structure. 2581da177e4SLinus Torvalds * @skb: received frame. 2591da177e4SLinus Torvalds * 2601da177e4SLinus Torvalds * Sends received pdus to the sap state machine. 2611da177e4SLinus Torvalds */ 2621da177e4SLinus Torvalds static void llc_sap_rcv(struct llc_sap *sap, struct sk_buff *skb) 2631da177e4SLinus Torvalds { 2641da177e4SLinus Torvalds struct llc_sap_state_ev *ev = llc_sap_ev(skb); 2651da177e4SLinus Torvalds 2661da177e4SLinus Torvalds ev->type = LLC_SAP_EV_TYPE_PDU; 2671da177e4SLinus Torvalds ev->reason = 0; 2681da177e4SLinus Torvalds llc_sap_state_process(sap, skb); 2691da177e4SLinus Torvalds } 2701da177e4SLinus Torvalds 2711da177e4SLinus Torvalds /** 2721da177e4SLinus Torvalds * llc_lookup_dgram - Finds dgram socket for the local sap/mac 2731da177e4SLinus Torvalds * @sap: SAP 2741da177e4SLinus Torvalds * @laddr: address of local LLC (MAC + SAP) 2751da177e4SLinus Torvalds * 2761da177e4SLinus Torvalds * Search socket list of the SAP and finds connection using the local 2771da177e4SLinus Torvalds * mac, and local sap. Returns pointer for socket found, %NULL otherwise. 2781da177e4SLinus Torvalds */ 2791da177e4SLinus Torvalds static struct sock *llc_lookup_dgram(struct llc_sap *sap, 2801da177e4SLinus Torvalds struct llc_addr *laddr) 2811da177e4SLinus Torvalds { 2821da177e4SLinus Torvalds struct sock *rc; 2831da177e4SLinus Torvalds struct hlist_node *node; 2841da177e4SLinus Torvalds 2851da177e4SLinus Torvalds read_lock_bh(&sap->sk_list.lock); 2861da177e4SLinus Torvalds sk_for_each(rc, node, &sap->sk_list.list) { 2871da177e4SLinus Torvalds struct llc_sock *llc = llc_sk(rc); 2881da177e4SLinus Torvalds 2891da177e4SLinus Torvalds if (rc->sk_type == SOCK_DGRAM && 2901da177e4SLinus Torvalds llc->laddr.lsap == laddr->lsap && 2911da177e4SLinus Torvalds llc_mac_match(llc->laddr.mac, laddr->mac)) { 2921da177e4SLinus Torvalds sock_hold(rc); 2931da177e4SLinus Torvalds goto found; 2941da177e4SLinus Torvalds } 2951da177e4SLinus Torvalds } 2961da177e4SLinus Torvalds rc = NULL; 2971da177e4SLinus Torvalds found: 2981da177e4SLinus Torvalds read_unlock_bh(&sap->sk_list.lock); 2991da177e4SLinus Torvalds return rc; 3001da177e4SLinus Torvalds } 3011da177e4SLinus Torvalds 3021da177e4SLinus Torvalds void llc_sap_handler(struct llc_sap *sap, struct sk_buff *skb) 3031da177e4SLinus Torvalds { 3041da177e4SLinus Torvalds struct llc_addr laddr; 3051da177e4SLinus Torvalds struct sock *sk; 3061da177e4SLinus Torvalds 3071da177e4SLinus Torvalds llc_pdu_decode_da(skb, laddr.mac); 3081da177e4SLinus Torvalds llc_pdu_decode_dsap(skb, &laddr.lsap); 3091da177e4SLinus Torvalds 3101da177e4SLinus Torvalds sk = llc_lookup_dgram(sap, &laddr); 3111da177e4SLinus Torvalds if (sk) { 3121da177e4SLinus Torvalds skb->sk = sk; 3131da177e4SLinus Torvalds llc_sap_rcv(sap, skb); 3141da177e4SLinus Torvalds sock_put(sk); 3151da177e4SLinus Torvalds } else 3161da177e4SLinus Torvalds kfree_skb(skb); 3171da177e4SLinus Torvalds } 318