llc_s_ac.c

  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 */
 37int 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
 43static 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 */
 72int 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 */
 92int 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 */
111int 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);
130out:
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 */
143int 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
154int 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);
179out:
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 */
191int 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 */
204int 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 */
218int 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}