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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * llc_sap.c - driver routines for SAP component. | |
3 | * | |
4 | * Copyright (c) 1997 by Procom Technology, Inc. | |
5 | * 2001-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br> | |
6 | * | |
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. | |
11 | * | |
12 | * See the GNU General Public License for more details. | |
13 | */ | |
14 | ||
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> | |
c752f073 | 24 | #include <net/tcp_states.h> |
1da177e4 LT |
25 | #include <linux/llc.h> |
26 | ||
f83f1768 JP |
27 | static int llc_mac_header_len(unsigned short devtype) |
28 | { | |
29 | switch (devtype) { | |
30 | case ARPHRD_ETHER: | |
31 | case ARPHRD_LOOPBACK: | |
32 | return sizeof(struct ethhdr); | |
33 | #ifdef CONFIG_TR | |
34 | case ARPHRD_IEEE802_TR: | |
35 | return sizeof(struct trh_hdr); | |
36 | #endif | |
37 | } | |
38 | return 0; | |
39 | } | |
40 | ||
1da177e4 LT |
41 | /** |
42 | * llc_alloc_frame - allocates sk_buff for frame | |
1d67e650 | 43 | * @dev: network device this skb will be sent over |
f83f1768 JP |
44 | * @type: pdu type to allocate |
45 | * @data_size: data size to allocate | |
1da177e4 LT |
46 | * |
47 | * Allocates an sk_buff for frame and initializes sk_buff fields. | |
48 | * Returns allocated skb or %NULL when out of memory. | |
49 | */ | |
f83f1768 JP |
50 | struct sk_buff *llc_alloc_frame(struct sock *sk, struct net_device *dev, |
51 | u8 type, u32 data_size) | |
1da177e4 | 52 | { |
f83f1768 JP |
53 | int hlen = type == LLC_PDU_TYPE_U ? 3 : 4; |
54 | struct sk_buff *skb; | |
55 | ||
56 | hlen += llc_mac_header_len(dev->type); | |
57 | skb = alloc_skb(hlen + data_size, GFP_ATOMIC); | |
1da177e4 LT |
58 | |
59 | if (skb) { | |
0a1b0ad9 | 60 | skb_reset_mac_header(skb); |
f83f1768 | 61 | skb_reserve(skb, hlen); |
c1d2bbe1 | 62 | skb_reset_network_header(skb); |
badff6d0 | 63 | skb_reset_transport_header(skb); |
1da177e4 | 64 | skb->protocol = htons(ETH_P_802_2); |
1d67e650 | 65 | skb->dev = dev; |
d389424e ACM |
66 | if (sk != NULL) |
67 | skb_set_owner_w(skb, sk); | |
1da177e4 LT |
68 | } |
69 | return skb; | |
70 | } | |
71 | ||
04e4223f | 72 | void llc_save_primitive(struct sock *sk, struct sk_buff* skb, u8 prim) |
1da177e4 | 73 | { |
8420e1b5 | 74 | struct sockaddr_llc *addr; |
1da177e4 LT |
75 | |
76 | /* save primitive for use by the user. */ | |
8420e1b5 | 77 | addr = llc_ui_skb_cb(skb); |
30a584d9 SH |
78 | |
79 | memset(addr, 0, sizeof(*addr)); | |
04e4223f | 80 | addr->sllc_family = sk->sk_family; |
1da177e4 LT |
81 | addr->sllc_arphrd = skb->dev->type; |
82 | addr->sllc_test = prim == LLC_TEST_PRIM; | |
83 | addr->sllc_xid = prim == LLC_XID_PRIM; | |
84 | addr->sllc_ua = prim == LLC_DATAUNIT_PRIM; | |
85 | llc_pdu_decode_sa(skb, addr->sllc_mac); | |
86 | llc_pdu_decode_ssap(skb, &addr->sllc_sap); | |
87 | } | |
88 | ||
89 | /** | |
90 | * llc_sap_rtn_pdu - Informs upper layer on rx of an UI, XID or TEST pdu. | |
91 | * @sap: pointer to SAP | |
92 | * @skb: received pdu | |
93 | */ | |
94 | void llc_sap_rtn_pdu(struct llc_sap *sap, struct sk_buff *skb) | |
95 | { | |
96 | struct llc_sap_state_ev *ev = llc_sap_ev(skb); | |
97 | struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb); | |
98 | ||
99 | switch (LLC_U_PDU_RSP(pdu)) { | |
100 | case LLC_1_PDU_CMD_TEST: | |
101 | ev->prim = LLC_TEST_PRIM; break; | |
102 | case LLC_1_PDU_CMD_XID: | |
103 | ev->prim = LLC_XID_PRIM; break; | |
104 | case LLC_1_PDU_CMD_UI: | |
105 | ev->prim = LLC_DATAUNIT_PRIM; break; | |
106 | } | |
107 | ev->ind_cfm_flag = LLC_IND; | |
108 | } | |
109 | ||
110 | /** | |
111 | * llc_find_sap_trans - finds transition for event | |
112 | * @sap: pointer to SAP | |
113 | * @skb: happened event | |
114 | * | |
115 | * This function finds transition that matches with happened event. | |
116 | * Returns the pointer to found transition on success or %NULL for | |
117 | * failure. | |
118 | */ | |
119 | static struct llc_sap_state_trans *llc_find_sap_trans(struct llc_sap *sap, | |
120 | struct sk_buff* skb) | |
121 | { | |
122 | int i = 0; | |
123 | struct llc_sap_state_trans *rc = NULL; | |
124 | struct llc_sap_state_trans **next_trans; | |
125 | struct llc_sap_state *curr_state = &llc_sap_state_table[sap->state - 1]; | |
126 | /* | |
127 | * Search thru events for this state until list exhausted or until | |
128 | * its obvious the event is not valid for the current state | |
129 | */ | |
130 | for (next_trans = curr_state->transitions; next_trans[i]->ev; i++) | |
131 | if (!next_trans[i]->ev(sap, skb)) { | |
132 | rc = next_trans[i]; /* got event match; return it */ | |
133 | break; | |
134 | } | |
135 | return rc; | |
136 | } | |
137 | ||
138 | /** | |
139 | * llc_exec_sap_trans_actions - execute actions related to event | |
140 | * @sap: pointer to SAP | |
141 | * @trans: pointer to transition that it's actions must be performed | |
142 | * @skb: happened event. | |
143 | * | |
144 | * This function executes actions that is related to happened event. | |
145 | * Returns 0 for success and 1 for failure of at least one action. | |
146 | */ | |
147 | static int llc_exec_sap_trans_actions(struct llc_sap *sap, | |
148 | struct llc_sap_state_trans *trans, | |
149 | struct sk_buff *skb) | |
150 | { | |
151 | int rc = 0; | |
152 | llc_sap_action_t *next_action = trans->ev_actions; | |
153 | ||
154 | for (; next_action && *next_action; next_action++) | |
155 | if ((*next_action)(sap, skb)) | |
156 | rc = 1; | |
157 | return rc; | |
158 | } | |
159 | ||
160 | /** | |
161 | * llc_sap_next_state - finds transition, execs actions & change SAP state | |
162 | * @sap: pointer to SAP | |
163 | * @skb: happened event | |
164 | * | |
165 | * This function finds transition that matches with happened event, then | |
166 | * executes related actions and finally changes state of SAP. It returns | |
167 | * 0 on success and 1 for failure. | |
168 | */ | |
169 | static int llc_sap_next_state(struct llc_sap *sap, struct sk_buff *skb) | |
170 | { | |
171 | int rc = 1; | |
172 | struct llc_sap_state_trans *trans; | |
173 | ||
174 | if (sap->state > LLC_NR_SAP_STATES) | |
175 | goto out; | |
176 | trans = llc_find_sap_trans(sap, skb); | |
177 | if (!trans) | |
178 | goto out; | |
179 | /* | |
180 | * Got the state to which we next transition; perform the actions | |
181 | * associated with this transition before actually transitioning to the | |
182 | * next state | |
183 | */ | |
184 | rc = llc_exec_sap_trans_actions(sap, trans, skb); | |
185 | if (rc) | |
186 | goto out; | |
187 | /* | |
188 | * Transition SAP to next state if all actions execute successfully | |
189 | */ | |
190 | sap->state = trans->next_state; | |
191 | out: | |
192 | return rc; | |
193 | } | |
194 | ||
195 | /** | |
196 | * llc_sap_state_process - sends event to SAP state machine | |
197 | * @sap: sap to use | |
198 | * @skb: pointer to occurred event | |
199 | * | |
200 | * After executing actions of the event, upper layer will be indicated | |
201 | * if needed(on receiving an UI frame). sk can be null for the | |
202 | * datalink_proto case. | |
203 | */ | |
204 | static void llc_sap_state_process(struct llc_sap *sap, struct sk_buff *skb) | |
205 | { | |
206 | struct llc_sap_state_ev *ev = llc_sap_ev(skb); | |
207 | ||
208 | /* | |
209 | * We have to hold the skb, because llc_sap_next_state | |
210 | * will kfree it in the sending path and we need to | |
211 | * look at the skb->cb, where we encode llc_sap_state_ev. | |
212 | */ | |
213 | skb_get(skb); | |
214 | ev->ind_cfm_flag = 0; | |
215 | llc_sap_next_state(sap, skb); | |
216 | if (ev->ind_cfm_flag == LLC_IND) { | |
217 | if (skb->sk->sk_state == TCP_LISTEN) | |
218 | kfree_skb(skb); | |
219 | else { | |
04e4223f | 220 | llc_save_primitive(skb->sk, skb, ev->prim); |
1da177e4 LT |
221 | |
222 | /* queue skb to the user. */ | |
223 | if (sock_queue_rcv_skb(skb->sk, skb)) | |
224 | kfree_skb(skb); | |
225 | } | |
d57b1869 | 226 | } |
1da177e4 LT |
227 | kfree_skb(skb); |
228 | } | |
229 | ||
230 | /** | |
231 | * llc_build_and_send_test_pkt - TEST interface for upper layers. | |
232 | * @sap: sap to use | |
233 | * @skb: packet to send | |
234 | * @dmac: destination mac address | |
235 | * @dsap: destination sap | |
236 | * | |
237 | * This function is called when upper layer wants to send a TEST pdu. | |
238 | * Returns 0 for success, 1 otherwise. | |
239 | */ | |
d57b1869 | 240 | void llc_build_and_send_test_pkt(struct llc_sap *sap, |
1da177e4 LT |
241 | struct sk_buff *skb, u8 *dmac, u8 dsap) |
242 | { | |
243 | struct llc_sap_state_ev *ev = llc_sap_ev(skb); | |
244 | ||
245 | ev->saddr.lsap = sap->laddr.lsap; | |
246 | ev->daddr.lsap = dsap; | |
247 | memcpy(ev->saddr.mac, skb->dev->dev_addr, IFHWADDRLEN); | |
248 | memcpy(ev->daddr.mac, dmac, IFHWADDRLEN); | |
d57b1869 | 249 | |
1da177e4 LT |
250 | ev->type = LLC_SAP_EV_TYPE_PRIM; |
251 | ev->prim = LLC_TEST_PRIM; | |
252 | ev->prim_type = LLC_PRIM_TYPE_REQ; | |
253 | llc_sap_state_process(sap, skb); | |
254 | } | |
255 | ||
256 | /** | |
257 | * llc_build_and_send_xid_pkt - XID interface for upper layers | |
258 | * @sap: sap to use | |
259 | * @skb: packet to send | |
260 | * @dmac: destination mac address | |
261 | * @dsap: destination sap | |
262 | * | |
263 | * This function is called when upper layer wants to send a XID pdu. | |
264 | * Returns 0 for success, 1 otherwise. | |
265 | */ | |
266 | void llc_build_and_send_xid_pkt(struct llc_sap *sap, struct sk_buff *skb, | |
267 | u8 *dmac, u8 dsap) | |
268 | { | |
269 | struct llc_sap_state_ev *ev = llc_sap_ev(skb); | |
270 | ||
271 | ev->saddr.lsap = sap->laddr.lsap; | |
272 | ev->daddr.lsap = dsap; | |
273 | memcpy(ev->saddr.mac, skb->dev->dev_addr, IFHWADDRLEN); | |
274 | memcpy(ev->daddr.mac, dmac, IFHWADDRLEN); | |
275 | ||
276 | ev->type = LLC_SAP_EV_TYPE_PRIM; | |
277 | ev->prim = LLC_XID_PRIM; | |
278 | ev->prim_type = LLC_PRIM_TYPE_REQ; | |
279 | llc_sap_state_process(sap, skb); | |
280 | } | |
281 | ||
282 | /** | |
283 | * llc_sap_rcv - sends received pdus to the sap state machine | |
284 | * @sap: current sap component structure. | |
285 | * @skb: received frame. | |
286 | * | |
287 | * Sends received pdus to the sap state machine. | |
288 | */ | |
3446b9d5 ACM |
289 | static void llc_sap_rcv(struct llc_sap *sap, struct sk_buff *skb, |
290 | struct sock *sk) | |
1da177e4 LT |
291 | { |
292 | struct llc_sap_state_ev *ev = llc_sap_ev(skb); | |
293 | ||
294 | ev->type = LLC_SAP_EV_TYPE_PDU; | |
295 | ev->reason = 0; | |
3446b9d5 | 296 | skb->sk = sk; |
1da177e4 LT |
297 | llc_sap_state_process(sap, skb); |
298 | } | |
299 | ||
300 | /** | |
301 | * llc_lookup_dgram - Finds dgram socket for the local sap/mac | |
302 | * @sap: SAP | |
303 | * @laddr: address of local LLC (MAC + SAP) | |
304 | * | |
305 | * Search socket list of the SAP and finds connection using the local | |
306 | * mac, and local sap. Returns pointer for socket found, %NULL otherwise. | |
307 | */ | |
308 | static struct sock *llc_lookup_dgram(struct llc_sap *sap, | |
bc0e6467 | 309 | const struct llc_addr *laddr) |
1da177e4 LT |
310 | { |
311 | struct sock *rc; | |
312 | struct hlist_node *node; | |
313 | ||
314 | read_lock_bh(&sap->sk_list.lock); | |
315 | sk_for_each(rc, node, &sap->sk_list.list) { | |
316 | struct llc_sock *llc = llc_sk(rc); | |
317 | ||
318 | if (rc->sk_type == SOCK_DGRAM && | |
319 | llc->laddr.lsap == laddr->lsap && | |
320 | llc_mac_match(llc->laddr.mac, laddr->mac)) { | |
321 | sock_hold(rc); | |
322 | goto found; | |
323 | } | |
324 | } | |
325 | rc = NULL; | |
326 | found: | |
327 | read_unlock_bh(&sap->sk_list.lock); | |
328 | return rc; | |
329 | } | |
330 | ||
bc0e6467 SH |
331 | /** |
332 | * llc_sap_mcast - Deliver multicast PDU's to all matching datagram sockets. | |
333 | * @sap: SAP | |
334 | * @laddr: address of local LLC (MAC + SAP) | |
335 | * | |
336 | * Search socket list of the SAP and finds connections with same sap. | |
337 | * Deliver clone to each. | |
338 | */ | |
339 | static void llc_sap_mcast(struct llc_sap *sap, | |
340 | const struct llc_addr *laddr, | |
341 | struct sk_buff *skb) | |
342 | { | |
343 | struct sock *sk; | |
344 | struct hlist_node *node; | |
345 | ||
346 | read_lock_bh(&sap->sk_list.lock); | |
347 | sk_for_each(sk, node, &sap->sk_list.list) { | |
348 | struct llc_sock *llc = llc_sk(sk); | |
349 | struct sk_buff *skb1; | |
350 | ||
351 | if (sk->sk_type != SOCK_DGRAM) | |
352 | continue; | |
353 | ||
354 | if (llc->laddr.lsap != laddr->lsap) | |
355 | continue; | |
356 | ||
7ee66fcb SH |
357 | if (llc->dev != skb->dev) |
358 | continue; | |
359 | ||
bc0e6467 SH |
360 | skb1 = skb_clone(skb, GFP_ATOMIC); |
361 | if (!skb1) | |
362 | break; | |
363 | ||
364 | sock_hold(sk); | |
3446b9d5 | 365 | llc_sap_rcv(sap, skb1, sk); |
bc0e6467 SH |
366 | sock_put(sk); |
367 | } | |
368 | read_unlock_bh(&sap->sk_list.lock); | |
369 | } | |
370 | ||
371 | ||
1da177e4 LT |
372 | void llc_sap_handler(struct llc_sap *sap, struct sk_buff *skb) |
373 | { | |
374 | struct llc_addr laddr; | |
1da177e4 LT |
375 | |
376 | llc_pdu_decode_da(skb, laddr.mac); | |
377 | llc_pdu_decode_dsap(skb, &laddr.lsap); | |
378 | ||
bc0e6467 SH |
379 | if (llc_mac_multicast(laddr.mac)) { |
380 | llc_sap_mcast(sap, &laddr, skb); | |
1da177e4 | 381 | kfree_skb(skb); |
bc0e6467 SH |
382 | } else { |
383 | struct sock *sk = llc_lookup_dgram(sap, &laddr); | |
384 | if (sk) { | |
3446b9d5 | 385 | llc_sap_rcv(sap, skb, sk); |
bc0e6467 SH |
386 | sock_put(sk); |
387 | } else | |
388 | kfree_skb(skb); | |
389 | } | |
1da177e4 | 390 | } |