diff options
Diffstat (limited to 'net/llc/llc_station.c')
| -rw-r--r-- | net/llc/llc_station.c | 125 |
1 files changed, 125 insertions, 0 deletions
diff --git a/net/llc/llc_station.c b/net/llc/llc_station.c new file mode 100644 index 000000000..c29170e76 --- /dev/null +++ b/net/llc/llc_station.c @@ -0,0 +1,125 @@ +/* + * 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; /* 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; /* 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); +} |