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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /net/llc/llc_station.c
Initial import
Diffstat (limited to 'net/llc/llc_station.c')
-rw-r--r--net/llc/llc_station.c125
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..204a8351e
--- /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 ? 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);
+}