1 /*
2 * llc_s_ac.c - actions performed during sap state transition.
3 *
4 * Description :
5 * Functions in this module are implementation of sap component actions.
6 * Details of actions can be found in IEEE-802.2 standard document.
7 * All functions have one sap and one event as input argument. All of
8 * them return 0 On success and 1 otherwise.
9 *
10 * Copyright (c) 1997 by Procom Technology, Inc.
11 * 2001-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
12 *
13 * This program can be redistributed or modified under the terms of the
14 * GNU General Public License as published by the Free Software Foundation.
15 * This program is distributed without any warranty or implied warranty
16 * of merchantability or fitness for a particular purpose.
17 *
18 * See the GNU General Public License for more details.
19 */
20
21 #include <linux/netdevice.h>
22 #include <net/llc.h>
23 #include <net/llc_pdu.h>
24 #include <net/llc_s_ac.h>
25 #include <net/llc_s_ev.h>
26 #include <net/llc_sap.h>
27
28
29 /**
30 * llc_sap_action_unitdata_ind - forward UI PDU to network layer
31 * @sap: SAP
32 * @skb: the event to forward
33 *
34 * Received a UI PDU from MAC layer; forward to network layer as a
35 * UNITDATA INDICATION; verify our event is the kind we expect
36 */
llc_sap_action_unitdata_ind(struct llc_sap * sap,struct sk_buff * skb)37 int llc_sap_action_unitdata_ind(struct llc_sap *sap, struct sk_buff *skb)
38 {
39 llc_sap_rtn_pdu(sap, skb);
40 return 0;
41 }
42
43 /**
44 * llc_sap_action_send_ui - sends UI PDU resp to UNITDATA REQ to MAC layer
45 * @sap: SAP
46 * @skb: the event to send
47 *
48 * Sends a UI PDU to the MAC layer in response to a UNITDATA REQUEST
49 * primitive from the network layer. Verifies event is a primitive type of
50 * event. Verify the primitive is a UNITDATA REQUEST.
51 */
llc_sap_action_send_ui(struct llc_sap * sap,struct sk_buff * skb)52 int llc_sap_action_send_ui(struct llc_sap *sap, struct sk_buff *skb)
53 {
54 struct llc_sap_state_ev *ev = llc_sap_ev(skb);
55 int rc;
56
57 llc_pdu_header_init(skb, LLC_PDU_TYPE_U, ev->saddr.lsap,
58 ev->daddr.lsap, LLC_PDU_CMD);
59 llc_pdu_init_as_ui_cmd(skb);
60 rc = llc_mac_hdr_init(skb, ev->saddr.mac, ev->daddr.mac);
61 if (likely(!rc)) {
62 skb_get(skb);
63 rc = dev_queue_xmit(skb);
64 }
65 return rc;
66 }
67
68 /**
69 * llc_sap_action_send_xid_c - send XID PDU as response to XID REQ
70 * @sap: SAP
71 * @skb: the event to send
72 *
73 * Send a XID command PDU to MAC layer in response to a XID REQUEST
74 * primitive from the network layer. Verify event is a primitive type
75 * event. Verify the primitive is a XID REQUEST.
76 */
llc_sap_action_send_xid_c(struct llc_sap * sap,struct sk_buff * skb)77 int llc_sap_action_send_xid_c(struct llc_sap *sap, struct sk_buff *skb)
78 {
79 struct llc_sap_state_ev *ev = llc_sap_ev(skb);
80 int rc;
81
82 llc_pdu_header_init(skb, LLC_PDU_TYPE_U_XID, ev->saddr.lsap,
83 ev->daddr.lsap, LLC_PDU_CMD);
84 llc_pdu_init_as_xid_cmd(skb, LLC_XID_NULL_CLASS_2, 0);
85 rc = llc_mac_hdr_init(skb, ev->saddr.mac, ev->daddr.mac);
86 if (likely(!rc)) {
87 skb_get(skb);
88 rc = dev_queue_xmit(skb);
89 }
90 return rc;
91 }
92
93 /**
94 * llc_sap_action_send_xid_r - send XID PDU resp to MAC for received XID
95 * @sap: SAP
96 * @skb: the event to send
97 *
98 * Send XID response PDU to MAC in response to an earlier received XID
99 * command PDU. Verify event is a PDU type event
100 */
llc_sap_action_send_xid_r(struct llc_sap * sap,struct sk_buff * skb)101 int llc_sap_action_send_xid_r(struct llc_sap *sap, struct sk_buff *skb)
102 {
103 u8 mac_da[ETH_ALEN], mac_sa[ETH_ALEN], dsap;
104 int rc = 1;
105 struct sk_buff *nskb;
106
107 llc_pdu_decode_sa(skb, mac_da);
108 llc_pdu_decode_da(skb, mac_sa);
109 llc_pdu_decode_ssap(skb, &dsap);
110 nskb = llc_alloc_frame(NULL, skb->dev, LLC_PDU_TYPE_U,
111 sizeof(struct llc_xid_info));
112 if (!nskb)
113 goto out;
114 llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap, dsap,
115 LLC_PDU_RSP);
116 llc_pdu_init_as_xid_rsp(nskb, LLC_XID_NULL_CLASS_2, 0);
117 rc = llc_mac_hdr_init(nskb, mac_sa, mac_da);
118 if (likely(!rc))
119 rc = dev_queue_xmit(nskb);
120 out:
121 return rc;
122 }
123
124 /**
125 * llc_sap_action_send_test_c - send TEST PDU to MAC in resp to TEST REQ
126 * @sap: SAP
127 * @skb: the event to send
128 *
129 * Send a TEST command PDU to the MAC layer in response to a TEST REQUEST
130 * primitive from the network layer. Verify event is a primitive type
131 * event; verify the primitive is a TEST REQUEST.
132 */
llc_sap_action_send_test_c(struct llc_sap * sap,struct sk_buff * skb)133 int llc_sap_action_send_test_c(struct llc_sap *sap, struct sk_buff *skb)
134 {
135 struct llc_sap_state_ev *ev = llc_sap_ev(skb);
136 int rc;
137
138 llc_pdu_header_init(skb, LLC_PDU_TYPE_U, ev->saddr.lsap,
139 ev->daddr.lsap, LLC_PDU_CMD);
140 llc_pdu_init_as_test_cmd(skb);
141 rc = llc_mac_hdr_init(skb, ev->saddr.mac, ev->daddr.mac);
142 if (likely(!rc)) {
143 skb_get(skb);
144 rc = dev_queue_xmit(skb);
145 }
146 return rc;
147 }
148
llc_sap_action_send_test_r(struct llc_sap * sap,struct sk_buff * skb)149 int llc_sap_action_send_test_r(struct llc_sap *sap, struct sk_buff *skb)
150 {
151 u8 mac_da[ETH_ALEN], mac_sa[ETH_ALEN], dsap;
152 struct sk_buff *nskb;
153 int rc = 1;
154 u32 data_size;
155
156 if (skb->mac_len < ETH_HLEN)
157 return 1;
158
159 llc_pdu_decode_sa(skb, mac_da);
160 llc_pdu_decode_da(skb, mac_sa);
161 llc_pdu_decode_ssap(skb, &dsap);
162
163 /* The test request command is type U (llc_len = 3) */
164 data_size = ntohs(eth_hdr(skb)->h_proto) - 3;
165 nskb = llc_alloc_frame(NULL, skb->dev, LLC_PDU_TYPE_U, data_size);
166 if (!nskb)
167 goto out;
168 llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap, dsap,
169 LLC_PDU_RSP);
170 llc_pdu_init_as_test_rsp(nskb, skb);
171 rc = llc_mac_hdr_init(nskb, mac_sa, mac_da);
172 if (likely(!rc))
173 rc = dev_queue_xmit(nskb);
174 out:
175 return rc;
176 }
177
178 /**
179 * llc_sap_action_report_status - report data link status to layer mgmt
180 * @sap: SAP
181 * @skb: the event to send
182 *
183 * Report data link status to layer management. Verify our event is the
184 * kind we expect.
185 */
llc_sap_action_report_status(struct llc_sap * sap,struct sk_buff * skb)186 int llc_sap_action_report_status(struct llc_sap *sap, struct sk_buff *skb)
187 {
188 return 0;
189 }
190
191 /**
192 * llc_sap_action_xid_ind - send XID PDU resp to net layer via XID IND
193 * @sap: SAP
194 * @skb: the event to send
195 *
196 * Send a XID response PDU to the network layer via a XID INDICATION
197 * primitive.
198 */
llc_sap_action_xid_ind(struct llc_sap * sap,struct sk_buff * skb)199 int llc_sap_action_xid_ind(struct llc_sap *sap, struct sk_buff *skb)
200 {
201 llc_sap_rtn_pdu(sap, skb);
202 return 0;
203 }
204
205 /**
206 * llc_sap_action_test_ind - send TEST PDU to net layer via TEST IND
207 * @sap: SAP
208 * @skb: the event to send
209 *
210 * Send a TEST response PDU to the network layer via a TEST INDICATION
211 * primitive. Verify our event is a PDU type event.
212 */
llc_sap_action_test_ind(struct llc_sap * sap,struct sk_buff * skb)213 int llc_sap_action_test_ind(struct llc_sap *sap, struct sk_buff *skb)
214 {
215 llc_sap_rtn_pdu(sap, skb);
216 return 0;
217 }
218