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 	llc_pdu_decode_sa(skb, mac_da);
157 	llc_pdu_decode_da(skb, mac_sa);
158 	llc_pdu_decode_ssap(skb, &dsap);
159 
160 	/* The test request command is type U (llc_len = 3) */
161 	data_size = ntohs(eth_hdr(skb)->h_proto) - 3;
162 	nskb = llc_alloc_frame(NULL, skb->dev, LLC_PDU_TYPE_U, data_size);
163 	if (!nskb)
164 		goto out;
165 	llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap, dsap,
166 			    LLC_PDU_RSP);
167 	llc_pdu_init_as_test_rsp(nskb, skb);
168 	rc = llc_mac_hdr_init(nskb, mac_sa, mac_da);
169 	if (likely(!rc))
170 		rc = dev_queue_xmit(nskb);
171 out:
172 	return rc;
173 }
174 
175 /**
176  *	llc_sap_action_report_status - report data link status to layer mgmt
177  *	@sap: SAP
178  *	@skb: the event to send
179  *
180  *	Report data link status to layer management. Verify our event is the
181  *	kind we expect.
182  */
llc_sap_action_report_status(struct llc_sap * sap,struct sk_buff * skb)183 int llc_sap_action_report_status(struct llc_sap *sap, struct sk_buff *skb)
184 {
185 	return 0;
186 }
187 
188 /**
189  *	llc_sap_action_xid_ind - send XID PDU resp to net layer via XID IND
190  *	@sap: SAP
191  *	@skb: the event to send
192  *
193  *	Send a XID response PDU to the network layer via a XID INDICATION
194  *	primitive.
195  */
llc_sap_action_xid_ind(struct llc_sap * sap,struct sk_buff * skb)196 int llc_sap_action_xid_ind(struct llc_sap *sap, struct sk_buff *skb)
197 {
198 	llc_sap_rtn_pdu(sap, skb);
199 	return 0;
200 }
201 
202 /**
203  *	llc_sap_action_test_ind - send TEST PDU to net layer via TEST IND
204  *	@sap: SAP
205  *	@skb: the event to send
206  *
207  *	Send a TEST response PDU to the network layer via a TEST INDICATION
208  *	primitive. Verify our event is a PDU type event.
209  */
llc_sap_action_test_ind(struct llc_sap * sap,struct sk_buff * skb)210 int llc_sap_action_test_ind(struct llc_sap *sap, struct sk_buff *skb)
211 {
212 	llc_sap_rtn_pdu(sap, skb);
213 	return 0;
214 }
215