/* * llc_station.c - station component of LLC * * Copyright (c) 1997 by Procom Technology, Inc. * 2001-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br> * * 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 <linux/init.h> #include <linux/module.h> #include <linux/slab.h> #include <net/llc.h> #include <net/llc_sap.h> #include <net/llc_conn.h> #include <net/llc_c_ac.h> #include <net/llc_s_ac.h> #include <net/llc_c_ev.h> #include <net/llc_c_st.h> #include <net/llc_s_ev.h> #include <net/llc_s_st.h> #include <net/llc_pdu.h> static int llc_stat_ev_rx_null_dsap_xid_c(struct sk_buff *skb) { struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb); return LLC_PDU_IS_CMD(pdu) && /* command PDU */ LLC_PDU_TYPE_IS_U(pdu) && /* U type PDU */ LLC_U_PDU_CMD(pdu) == LLC_1_PDU_CMD_XID && !pdu->dsap ? 0 : 1; /* NULL DSAP value */ } static int llc_stat_ev_rx_null_dsap_test_c(struct sk_buff *skb) { struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb); return LLC_PDU_IS_CMD(pdu) && /* command PDU */ LLC_PDU_TYPE_IS_U(pdu) && /* U type PDU */ LLC_U_PDU_CMD(pdu) == LLC_1_PDU_CMD_TEST && !pdu->dsap ? 0 : 1; /* NULL DSAP */ } static int llc_station_ac_send_xid_r(struct sk_buff *skb) { u8 mac_da[ETH_ALEN], dsap; int rc = 1; struct sk_buff *nskb = llc_alloc_frame(NULL, skb->dev, LLC_PDU_TYPE_U, sizeof(struct llc_xid_info)); if (!nskb) goto out; rc = 0; llc_pdu_decode_sa(skb, mac_da); llc_pdu_decode_ssap(skb, &dsap); llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, 0, dsap, LLC_PDU_RSP); llc_pdu_init_as_xid_rsp(nskb, LLC_XID_NULL_CLASS_2, 127); rc = llc_mac_hdr_init(nskb, skb->dev->dev_addr, mac_da); if (unlikely(rc)) goto free; dev_queue_xmit(nskb); out: return rc; free: kfree_skb(nskb); goto out; } static int llc_station_ac_send_test_r(struct sk_buff *skb) { u8 mac_da[ETH_ALEN], dsap; int rc = 1; u32 data_size; struct sk_buff *nskb; /* The test request command is type U (llc_len = 3) */ data_size = ntohs(eth_hdr(skb)->h_proto) - 3; nskb = llc_alloc_frame(NULL, skb->dev, LLC_PDU_TYPE_U, data_size); if (!nskb) goto out; rc = 0; llc_pdu_decode_sa(skb, mac_da); llc_pdu_decode_ssap(skb, &dsap); llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, 0, dsap, LLC_PDU_RSP); llc_pdu_init_as_test_rsp(nskb, skb); rc = llc_mac_hdr_init(nskb, skb->dev->dev_addr, mac_da); if (unlikely(rc)) goto free; dev_queue_xmit(nskb); out: return rc; free: kfree_skb(nskb); goto out; } /** * llc_station_rcv - send received pdu to the station state machine * @skb: received frame. * * Sends data unit to station state machine. */ static void llc_station_rcv(struct sk_buff *skb) { if (llc_stat_ev_rx_null_dsap_xid_c(skb)) llc_station_ac_send_xid_r(skb); else if (llc_stat_ev_rx_null_dsap_test_c(skb)) llc_station_ac_send_test_r(skb); kfree_skb(skb); } void __init llc_station_init(void) { llc_set_station_handler(llc_station_rcv); } void llc_station_exit(void) { llc_set_station_handler(NULL); }