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.
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>
24 #include <net/tcp_states.h>
25 #include <linux/llc.h>
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
);
39 skb_reset_mac_header(skb
);
41 skb_reset_network_header(skb
);
42 skb_reset_transport_header(skb
);
43 skb
->protocol
= htons(ETH_P_802_2
);
46 skb_set_owner_w(skb
, sk
);
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
);
69 * llc_sap_rtn_pdu - Informs upper layer on rx of an UI, XID or TEST pdu.
70 * @sap: pointer to SAP
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
;
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
98 static struct llc_sap_state_trans
*llc_find_sap_trans(struct llc_sap
*sap
,
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 */
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
,
131 llc_sap_action_t
*next_action
= trans
->ev_actions
;
133 for (; next_action
&& *next_action
; next_action
++)
134 if ((*next_action
)(sap
, skb
))
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
)
151 struct llc_sap_state_trans
*trans
;
153 if (sap
->state
> LLC_NR_SAP_STATES
)
155 trans
= llc_find_sap_trans(sap
, skb
);
159 * Got the state to which we next transition; perform the actions
160 * associated with this transition before actually transitioning to the
163 rc
= llc_exec_sap_trans_actions(sap
, trans
, skb
);
167 * Transition SAP to next state if all actions execute successfully
169 sap
->state
= trans
->next_state
;
175 * llc_sap_state_process - sends event to SAP state machine
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.
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
)
199 llc_save_primitive(skb
->sk
, skb
, ev
->prim
);
201 /* queue skb to the user. */
202 if (sock_queue_rcv_skb(skb
->sk
, skb
))
210 * llc_build_and_send_test_pkt - TEST interface for upper layers.
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
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
,
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
;
274 llc_sap_state_process(sap
, skb
);
278 * llc_lookup_dgram - Finds dgram socket for the local sap/mac
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
)
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
)) {
304 read_unlock_bh(&sap
->sk_list
.lock
);
309 * llc_sap_mcast - Deliver multicast PDU's to all matching datagram sockets.
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
,
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
)
331 if (llc
->laddr
.lsap
!= laddr
->lsap
)
334 if (llc
->dev
!= skb
->dev
)
337 skb1
= skb_clone(skb
, GFP_ATOMIC
);
342 skb_set_owner_r(skb1
, sk
);
343 llc_sap_rcv(sap
, skb1
);
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
);
361 struct sock
*sk
= llc_lookup_dgram(sap
, &laddr
);
363 skb_set_owner_r(skb
, sk
);
364 llc_sap_rcv(sap
, skb
);