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 #include <net/sock.h>
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
llc_prepare_and_xmit(struct sk_buff * skb)43 static int llc_prepare_and_xmit(struct sk_buff *skb)
44 {
45 struct llc_sap_state_ev *ev = llc_sap_ev(skb);
46 struct sk_buff *nskb;
47 int rc;
48
49 rc = llc_mac_hdr_init(skb, ev->saddr.mac, ev->daddr.mac);
50 if (rc)
51 return rc;
52
53 nskb = skb_clone(skb, GFP_ATOMIC);
54 if (!nskb)
55 return -ENOMEM;
56
57 if (skb->sk)
58 skb_set_owner_w(nskb, skb->sk);
59
60 return dev_queue_xmit(nskb);
61 }
62
63 /**
64 * llc_sap_action_send_ui - sends UI PDU resp to UNITDATA REQ to MAC layer
65 * @sap: SAP
66 * @skb: the event to send
67 *
68 * Sends a UI PDU to the MAC layer in response to a UNITDATA REQUEST
69 * primitive from the network layer. Verifies event is a primitive type of
70 * event. Verify the primitive is a UNITDATA REQUEST.
71 */
llc_sap_action_send_ui(struct llc_sap * sap,struct sk_buff * skb)72 int llc_sap_action_send_ui(struct llc_sap *sap, struct sk_buff *skb)
73 {
74 struct llc_sap_state_ev *ev = llc_sap_ev(skb);
75
76 llc_pdu_header_init(skb, LLC_PDU_TYPE_U, ev->saddr.lsap,
77 ev->daddr.lsap, LLC_PDU_CMD);
78 llc_pdu_init_as_ui_cmd(skb);
79
80 return llc_prepare_and_xmit(skb);
81 }
82
83 /**
84 * llc_sap_action_send_xid_c - send XID PDU as response to XID REQ
85 * @sap: SAP
86 * @skb: the event to send
87 *
88 * Send a XID command PDU to MAC layer in response to a XID REQUEST
89 * primitive from the network layer. Verify event is a primitive type
90 * event. Verify the primitive is a XID REQUEST.
91 */
llc_sap_action_send_xid_c(struct llc_sap * sap,struct sk_buff * skb)92 int llc_sap_action_send_xid_c(struct llc_sap *sap, struct sk_buff *skb)
93 {
94 struct llc_sap_state_ev *ev = llc_sap_ev(skb);
95
96 llc_pdu_header_init(skb, LLC_PDU_TYPE_U_XID, ev->saddr.lsap,
97 ev->daddr.lsap, LLC_PDU_CMD);
98 llc_pdu_init_as_xid_cmd(skb, LLC_XID_NULL_CLASS_2, 0);
99
100 return llc_prepare_and_xmit(skb);
101 }
102
103 /**
104 * llc_sap_action_send_xid_r - send XID PDU resp to MAC for received XID
105 * @sap: SAP
106 * @skb: the event to send
107 *
108 * Send XID response PDU to MAC in response to an earlier received XID
109 * command PDU. Verify event is a PDU type event
110 */
llc_sap_action_send_xid_r(struct llc_sap * sap,struct sk_buff * skb)111 int llc_sap_action_send_xid_r(struct llc_sap *sap, struct sk_buff *skb)
112 {
113 u8 mac_da[ETH_ALEN], mac_sa[ETH_ALEN], dsap;
114 int rc = 1;
115 struct sk_buff *nskb;
116
117 llc_pdu_decode_sa(skb, mac_da);
118 llc_pdu_decode_da(skb, mac_sa);
119 llc_pdu_decode_ssap(skb, &dsap);
120 nskb = llc_alloc_frame(NULL, skb->dev, LLC_PDU_TYPE_U,
121 sizeof(struct llc_xid_info));
122 if (!nskb)
123 goto out;
124 llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap, dsap,
125 LLC_PDU_RSP);
126 llc_pdu_init_as_xid_rsp(nskb, LLC_XID_NULL_CLASS_2, 0);
127 rc = llc_mac_hdr_init(nskb, mac_sa, mac_da);
128 if (likely(!rc))
129 rc = dev_queue_xmit(nskb);
130 out:
131 return rc;
132 }
133
134 /**
135 * llc_sap_action_send_test_c - send TEST PDU to MAC in resp to TEST REQ
136 * @sap: SAP
137 * @skb: the event to send
138 *
139 * Send a TEST command PDU to the MAC layer in response to a TEST REQUEST
140 * primitive from the network layer. Verify event is a primitive type
141 * event; verify the primitive is a TEST REQUEST.
142 */
llc_sap_action_send_test_c(struct llc_sap * sap,struct sk_buff * skb)143 int llc_sap_action_send_test_c(struct llc_sap *sap, struct sk_buff *skb)
144 {
145 struct llc_sap_state_ev *ev = llc_sap_ev(skb);
146
147 llc_pdu_header_init(skb, LLC_PDU_TYPE_U, ev->saddr.lsap,
148 ev->daddr.lsap, LLC_PDU_CMD);
149 llc_pdu_init_as_test_cmd(skb);
150
151 return llc_prepare_and_xmit(skb);
152 }
153
llc_sap_action_send_test_r(struct llc_sap * sap,struct sk_buff * skb)154 int llc_sap_action_send_test_r(struct llc_sap *sap, struct sk_buff *skb)
155 {
156 u8 mac_da[ETH_ALEN], mac_sa[ETH_ALEN], dsap;
157 struct sk_buff *nskb;
158 int rc = 1;
159 u32 data_size;
160
161 if (skb->mac_len < ETH_HLEN)
162 return 1;
163
164 llc_pdu_decode_sa(skb, mac_da);
165 llc_pdu_decode_da(skb, mac_sa);
166 llc_pdu_decode_ssap(skb, &dsap);
167
168 /* The test request command is type U (llc_len = 3) */
169 data_size = ntohs(eth_hdr(skb)->h_proto) - 3;
170 nskb = llc_alloc_frame(NULL, skb->dev, LLC_PDU_TYPE_U, data_size);
171 if (!nskb)
172 goto out;
173 llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap, dsap,
174 LLC_PDU_RSP);
175 llc_pdu_init_as_test_rsp(nskb, skb);
176 rc = llc_mac_hdr_init(nskb, mac_sa, mac_da);
177 if (likely(!rc))
178 rc = dev_queue_xmit(nskb);
179 out:
180 return rc;
181 }
182
183 /**
184 * llc_sap_action_report_status - report data link status to layer mgmt
185 * @sap: SAP
186 * @skb: the event to send
187 *
188 * Report data link status to layer management. Verify our event is the
189 * kind we expect.
190 */
llc_sap_action_report_status(struct llc_sap * sap,struct sk_buff * skb)191 int llc_sap_action_report_status(struct llc_sap *sap, struct sk_buff *skb)
192 {
193 return 0;
194 }
195
196 /**
197 * llc_sap_action_xid_ind - send XID PDU resp to net layer via XID IND
198 * @sap: SAP
199 * @skb: the event to send
200 *
201 * Send a XID response PDU to the network layer via a XID INDICATION
202 * primitive.
203 */
llc_sap_action_xid_ind(struct llc_sap * sap,struct sk_buff * skb)204 int llc_sap_action_xid_ind(struct llc_sap *sap, struct sk_buff *skb)
205 {
206 llc_sap_rtn_pdu(sap, skb);
207 return 0;
208 }
209
210 /**
211 * llc_sap_action_test_ind - send TEST PDU to net layer via TEST IND
212 * @sap: SAP
213 * @skb: the event to send
214 *
215 * Send a TEST response PDU to the network layer via a TEST INDICATION
216 * primitive. Verify our event is a PDU type event.
217 */
llc_sap_action_test_ind(struct llc_sap * sap,struct sk_buff * skb)218 int llc_sap_action_test_ind(struct llc_sap *sap, struct sk_buff *skb)
219 {
220 llc_sap_rtn_pdu(sap, skb);
221 return 0;
222 }
223