ACPI: Delete the IRQ operation in throttling controll via PTC
[linux-2.6/mini2440.git] / net / llc / llc_sap.c
blob2525165e2e8fdb8a53e774f82f72f8acba4eb94e
1 /*
2 * llc_sap.c - driver routines for SAP component.
4 * Copyright (c) 1997 by Procom Technology, Inc.
5 * 2001-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
7 * This program can be redistributed or modified under the terms of the
8 * GNU General Public License as published by the Free Software Foundation.
9 * This program is distributed without any warranty or implied warranty
10 * of merchantability or fitness for a particular purpose.
12 * See the GNU General Public License for more details.
15 #include <net/llc.h>
16 #include <net/llc_if.h>
17 #include <net/llc_conn.h>
18 #include <net/llc_pdu.h>
19 #include <net/llc_sap.h>
20 #include <net/llc_s_ac.h>
21 #include <net/llc_s_ev.h>
22 #include <net/llc_s_st.h>
23 #include <net/sock.h>
24 #include <net/tcp_states.h>
25 #include <linux/llc.h>
27 /**
28 * llc_alloc_frame - allocates sk_buff for frame
29 * @dev: network device this skb will be sent over
31 * Allocates an sk_buff for frame and initializes sk_buff fields.
32 * Returns allocated skb or %NULL when out of memory.
34 struct sk_buff *llc_alloc_frame(struct sock *sk, struct net_device *dev)
36 struct sk_buff *skb = alloc_skb(128, GFP_ATOMIC);
38 if (skb) {
39 skb_reset_mac_header(skb);
40 skb_reserve(skb, 50);
41 skb_reset_network_header(skb);
42 skb_reset_transport_header(skb);
43 skb->protocol = htons(ETH_P_802_2);
44 skb->dev = dev;
45 if (sk != NULL)
46 skb_set_owner_w(skb, sk);
48 return skb;
51 void llc_save_primitive(struct sock *sk, struct sk_buff* skb, u8 prim)
53 struct sockaddr_llc *addr;
55 /* save primitive for use by the user. */
56 addr = llc_ui_skb_cb(skb);
58 memset(addr, 0, sizeof(*addr));
59 addr->sllc_family = sk->sk_family;
60 addr->sllc_arphrd = skb->dev->type;
61 addr->sllc_test = prim == LLC_TEST_PRIM;
62 addr->sllc_xid = prim == LLC_XID_PRIM;
63 addr->sllc_ua = prim == LLC_DATAUNIT_PRIM;
64 llc_pdu_decode_sa(skb, addr->sllc_mac);
65 llc_pdu_decode_ssap(skb, &addr->sllc_sap);
68 /**
69 * llc_sap_rtn_pdu - Informs upper layer on rx of an UI, XID or TEST pdu.
70 * @sap: pointer to SAP
71 * @skb: received pdu
73 void llc_sap_rtn_pdu(struct llc_sap *sap, struct sk_buff *skb)
75 struct llc_sap_state_ev *ev = llc_sap_ev(skb);
76 struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
78 switch (LLC_U_PDU_RSP(pdu)) {
79 case LLC_1_PDU_CMD_TEST:
80 ev->prim = LLC_TEST_PRIM; break;
81 case LLC_1_PDU_CMD_XID:
82 ev->prim = LLC_XID_PRIM; break;
83 case LLC_1_PDU_CMD_UI:
84 ev->prim = LLC_DATAUNIT_PRIM; break;
86 ev->ind_cfm_flag = LLC_IND;
89 /**
90 * llc_find_sap_trans - finds transition for event
91 * @sap: pointer to SAP
92 * @skb: happened event
94 * This function finds transition that matches with happened event.
95 * Returns the pointer to found transition on success or %NULL for
96 * failure.
98 static struct llc_sap_state_trans *llc_find_sap_trans(struct llc_sap *sap,
99 struct sk_buff* skb)
101 int i = 0;
102 struct llc_sap_state_trans *rc = NULL;
103 struct llc_sap_state_trans **next_trans;
104 struct llc_sap_state *curr_state = &llc_sap_state_table[sap->state - 1];
106 * Search thru events for this state until list exhausted or until
107 * its obvious the event is not valid for the current state
109 for (next_trans = curr_state->transitions; next_trans[i]->ev; i++)
110 if (!next_trans[i]->ev(sap, skb)) {
111 rc = next_trans[i]; /* got event match; return it */
112 break;
114 return rc;
118 * llc_exec_sap_trans_actions - execute actions related to event
119 * @sap: pointer to SAP
120 * @trans: pointer to transition that it's actions must be performed
121 * @skb: happened event.
123 * This function executes actions that is related to happened event.
124 * Returns 0 for success and 1 for failure of at least one action.
126 static int llc_exec_sap_trans_actions(struct llc_sap *sap,
127 struct llc_sap_state_trans *trans,
128 struct sk_buff *skb)
130 int rc = 0;
131 llc_sap_action_t *next_action = trans->ev_actions;
133 for (; next_action && *next_action; next_action++)
134 if ((*next_action)(sap, skb))
135 rc = 1;
136 return rc;
140 * llc_sap_next_state - finds transition, execs actions & change SAP state
141 * @sap: pointer to SAP
142 * @skb: happened event
144 * This function finds transition that matches with happened event, then
145 * executes related actions and finally changes state of SAP. It returns
146 * 0 on success and 1 for failure.
148 static int llc_sap_next_state(struct llc_sap *sap, struct sk_buff *skb)
150 int rc = 1;
151 struct llc_sap_state_trans *trans;
153 if (sap->state > LLC_NR_SAP_STATES)
154 goto out;
155 trans = llc_find_sap_trans(sap, skb);
156 if (!trans)
157 goto out;
159 * Got the state to which we next transition; perform the actions
160 * associated with this transition before actually transitioning to the
161 * next state
163 rc = llc_exec_sap_trans_actions(sap, trans, skb);
164 if (rc)
165 goto out;
167 * Transition SAP to next state if all actions execute successfully
169 sap->state = trans->next_state;
170 out:
171 return rc;
175 * llc_sap_state_process - sends event to SAP state machine
176 * @sap: sap to use
177 * @skb: pointer to occurred event
179 * After executing actions of the event, upper layer will be indicated
180 * if needed(on receiving an UI frame). sk can be null for the
181 * datalink_proto case.
183 static void llc_sap_state_process(struct llc_sap *sap, struct sk_buff *skb)
185 struct llc_sap_state_ev *ev = llc_sap_ev(skb);
188 * We have to hold the skb, because llc_sap_next_state
189 * will kfree it in the sending path and we need to
190 * look at the skb->cb, where we encode llc_sap_state_ev.
192 skb_get(skb);
193 ev->ind_cfm_flag = 0;
194 llc_sap_next_state(sap, skb);
195 if (ev->ind_cfm_flag == LLC_IND) {
196 if (skb->sk->sk_state == TCP_LISTEN)
197 kfree_skb(skb);
198 else {
199 llc_save_primitive(skb->sk, skb, ev->prim);
201 /* queue skb to the user. */
202 if (sock_queue_rcv_skb(skb->sk, skb))
203 kfree_skb(skb);
206 kfree_skb(skb);
210 * llc_build_and_send_test_pkt - TEST interface for upper layers.
211 * @sap: sap to use
212 * @skb: packet to send
213 * @dmac: destination mac address
214 * @dsap: destination sap
216 * This function is called when upper layer wants to send a TEST pdu.
217 * Returns 0 for success, 1 otherwise.
219 void llc_build_and_send_test_pkt(struct llc_sap *sap,
220 struct sk_buff *skb, u8 *dmac, u8 dsap)
222 struct llc_sap_state_ev *ev = llc_sap_ev(skb);
224 ev->saddr.lsap = sap->laddr.lsap;
225 ev->daddr.lsap = dsap;
226 memcpy(ev->saddr.mac, skb->dev->dev_addr, IFHWADDRLEN);
227 memcpy(ev->daddr.mac, dmac, IFHWADDRLEN);
229 ev->type = LLC_SAP_EV_TYPE_PRIM;
230 ev->prim = LLC_TEST_PRIM;
231 ev->prim_type = LLC_PRIM_TYPE_REQ;
232 llc_sap_state_process(sap, skb);
236 * llc_build_and_send_xid_pkt - XID interface for upper layers
237 * @sap: sap to use
238 * @skb: packet to send
239 * @dmac: destination mac address
240 * @dsap: destination sap
242 * This function is called when upper layer wants to send a XID pdu.
243 * Returns 0 for success, 1 otherwise.
245 void llc_build_and_send_xid_pkt(struct llc_sap *sap, struct sk_buff *skb,
246 u8 *dmac, u8 dsap)
248 struct llc_sap_state_ev *ev = llc_sap_ev(skb);
250 ev->saddr.lsap = sap->laddr.lsap;
251 ev->daddr.lsap = dsap;
252 memcpy(ev->saddr.mac, skb->dev->dev_addr, IFHWADDRLEN);
253 memcpy(ev->daddr.mac, dmac, IFHWADDRLEN);
255 ev->type = LLC_SAP_EV_TYPE_PRIM;
256 ev->prim = LLC_XID_PRIM;
257 ev->prim_type = LLC_PRIM_TYPE_REQ;
258 llc_sap_state_process(sap, skb);
262 * llc_sap_rcv - sends received pdus to the sap state machine
263 * @sap: current sap component structure.
264 * @skb: received frame.
266 * Sends received pdus to the sap state machine.
268 static void llc_sap_rcv(struct llc_sap *sap, struct sk_buff *skb)
270 struct llc_sap_state_ev *ev = llc_sap_ev(skb);
272 ev->type = LLC_SAP_EV_TYPE_PDU;
273 ev->reason = 0;
274 llc_sap_state_process(sap, skb);
278 * llc_lookup_dgram - Finds dgram socket for the local sap/mac
279 * @sap: SAP
280 * @laddr: address of local LLC (MAC + SAP)
282 * Search socket list of the SAP and finds connection using the local
283 * mac, and local sap. Returns pointer for socket found, %NULL otherwise.
285 static struct sock *llc_lookup_dgram(struct llc_sap *sap,
286 const struct llc_addr *laddr)
288 struct sock *rc;
289 struct hlist_node *node;
291 read_lock_bh(&sap->sk_list.lock);
292 sk_for_each(rc, node, &sap->sk_list.list) {
293 struct llc_sock *llc = llc_sk(rc);
295 if (rc->sk_type == SOCK_DGRAM &&
296 llc->laddr.lsap == laddr->lsap &&
297 llc_mac_match(llc->laddr.mac, laddr->mac)) {
298 sock_hold(rc);
299 goto found;
302 rc = NULL;
303 found:
304 read_unlock_bh(&sap->sk_list.lock);
305 return rc;
309 * llc_sap_mcast - Deliver multicast PDU's to all matching datagram sockets.
310 * @sap: SAP
311 * @laddr: address of local LLC (MAC + SAP)
313 * Search socket list of the SAP and finds connections with same sap.
314 * Deliver clone to each.
316 static void llc_sap_mcast(struct llc_sap *sap,
317 const struct llc_addr *laddr,
318 struct sk_buff *skb)
320 struct sock *sk;
321 struct hlist_node *node;
323 read_lock_bh(&sap->sk_list.lock);
324 sk_for_each(sk, node, &sap->sk_list.list) {
325 struct llc_sock *llc = llc_sk(sk);
326 struct sk_buff *skb1;
328 if (sk->sk_type != SOCK_DGRAM)
329 continue;
331 if (llc->laddr.lsap != laddr->lsap)
332 continue;
334 if (llc->dev != skb->dev)
335 continue;
337 skb1 = skb_clone(skb, GFP_ATOMIC);
338 if (!skb1)
339 break;
341 sock_hold(sk);
342 skb_set_owner_r(skb1, sk);
343 llc_sap_rcv(sap, skb1);
344 sock_put(sk);
346 read_unlock_bh(&sap->sk_list.lock);
350 void llc_sap_handler(struct llc_sap *sap, struct sk_buff *skb)
352 struct llc_addr laddr;
354 llc_pdu_decode_da(skb, laddr.mac);
355 llc_pdu_decode_dsap(skb, &laddr.lsap);
357 if (llc_mac_multicast(laddr.mac)) {
358 llc_sap_mcast(sap, &laddr, skb);
359 kfree_skb(skb);
360 } else {
361 struct sock *sk = llc_lookup_dgram(sap, &laddr);
362 if (sk) {
363 skb_set_owner_r(skb, sk);
364 llc_sap_rcv(sap, skb);
365 sock_put(sk);
366 } else
367 kfree_skb(skb);