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123 lines
3.2 KiB
123 lines
3.2 KiB
/* |
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* llc_station.c - station component of LLC |
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* |
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* Copyright (c) 1997 by Procom Technology, Inc. |
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* 2001-2003 by Arnaldo Carvalho de Melo <[email protected]> |
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* |
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* This program can be redistributed or modified under the terms of the |
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* GNU General Public License as published by the Free Software Foundation. |
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* This program is distributed without any warranty or implied warranty |
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* of merchantability or fitness for a particular purpose. |
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* |
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* See the GNU General Public License for more details. |
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*/ |
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#include <linux/init.h> |
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#include <linux/module.h> |
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#include <linux/slab.h> |
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#include <net/llc.h> |
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#include <net/llc_sap.h> |
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#include <net/llc_conn.h> |
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#include <net/llc_c_ac.h> |
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#include <net/llc_s_ac.h> |
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#include <net/llc_c_ev.h> |
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#include <net/llc_c_st.h> |
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#include <net/llc_s_ev.h> |
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#include <net/llc_s_st.h> |
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#include <net/llc_pdu.h> |
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static int llc_stat_ev_rx_null_dsap_xid_c(struct sk_buff *skb) |
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{ |
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struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb); |
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return LLC_PDU_IS_CMD(pdu) && /* command PDU */ |
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LLC_PDU_TYPE_IS_U(pdu) && /* U type PDU */ |
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LLC_U_PDU_CMD(pdu) == LLC_1_PDU_CMD_XID && |
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!pdu->dsap; /* NULL DSAP value */ |
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} |
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static int llc_stat_ev_rx_null_dsap_test_c(struct sk_buff *skb) |
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{ |
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struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb); |
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return LLC_PDU_IS_CMD(pdu) && /* command PDU */ |
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LLC_PDU_TYPE_IS_U(pdu) && /* U type PDU */ |
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LLC_U_PDU_CMD(pdu) == LLC_1_PDU_CMD_TEST && |
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!pdu->dsap; /* NULL DSAP */ |
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} |
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static int llc_station_ac_send_xid_r(struct sk_buff *skb) |
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{ |
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u8 mac_da[ETH_ALEN], dsap; |
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int rc = 1; |
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struct sk_buff *nskb = llc_alloc_frame(NULL, skb->dev, LLC_PDU_TYPE_U, |
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sizeof(struct llc_xid_info)); |
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if (!nskb) |
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goto out; |
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llc_pdu_decode_sa(skb, mac_da); |
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llc_pdu_decode_ssap(skb, &dsap); |
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llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, 0, dsap, LLC_PDU_RSP); |
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llc_pdu_init_as_xid_rsp(nskb, LLC_XID_NULL_CLASS_2, 127); |
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rc = llc_mac_hdr_init(nskb, skb->dev->dev_addr, mac_da); |
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if (unlikely(rc)) |
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goto free; |
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dev_queue_xmit(nskb); |
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out: |
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return rc; |
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free: |
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kfree_skb(nskb); |
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goto out; |
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} |
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static int llc_station_ac_send_test_r(struct sk_buff *skb) |
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{ |
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u8 mac_da[ETH_ALEN], dsap; |
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int rc = 1; |
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u32 data_size; |
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struct sk_buff *nskb; |
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/* The test request command is type U (llc_len = 3) */ |
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data_size = ntohs(eth_hdr(skb)->h_proto) - 3; |
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nskb = llc_alloc_frame(NULL, skb->dev, LLC_PDU_TYPE_U, data_size); |
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if (!nskb) |
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goto out; |
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llc_pdu_decode_sa(skb, mac_da); |
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llc_pdu_decode_ssap(skb, &dsap); |
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llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, 0, dsap, LLC_PDU_RSP); |
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llc_pdu_init_as_test_rsp(nskb, skb); |
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rc = llc_mac_hdr_init(nskb, skb->dev->dev_addr, mac_da); |
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if (unlikely(rc)) |
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goto free; |
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dev_queue_xmit(nskb); |
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out: |
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return rc; |
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free: |
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kfree_skb(nskb); |
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goto out; |
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} |
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/** |
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* llc_station_rcv - send received pdu to the station state machine |
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* @skb: received frame. |
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* |
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* Sends data unit to station state machine. |
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*/ |
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static void llc_station_rcv(struct sk_buff *skb) |
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{ |
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if (llc_stat_ev_rx_null_dsap_xid_c(skb)) |
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llc_station_ac_send_xid_r(skb); |
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else if (llc_stat_ev_rx_null_dsap_test_c(skb)) |
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llc_station_ac_send_test_r(skb); |
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kfree_skb(skb); |
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} |
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void __init llc_station_init(void) |
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{ |
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llc_set_station_handler(llc_station_rcv); |
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} |
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void llc_station_exit(void) |
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{ |
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llc_set_station_handler(NULL); |
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}
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