forked from analogdevicesinc/linux
-
Notifications
You must be signed in to change notification settings - Fork 3
/
llc_station.c
125 lines (113 loc) · 3.22 KB
/
llc_station.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
/*
* llc_station.c - station component of LLC
*
* Copyright (c) 1997 by Procom Technology, Inc.
* 2001-2003 by Arnaldo Carvalho de Melo <[email protected]>
*
* 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);
}