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 net_device
*dev
)
36 struct sk_buff
*skb
= alloc_skb(128, GFP_ATOMIC
);
40 skb
->nh
.raw
= skb
->h
.raw
= skb
->data
;
41 skb
->protocol
= htons(ETH_P_802_2
);
43 skb
->mac
.raw
= skb
->head
;
48 void llc_save_primitive(struct sk_buff
* skb
, u8 prim
)
50 struct sockaddr_llc
*addr
= llc_ui_skb_cb(skb
);
52 /* save primitive for use by the user. */
53 addr
->sllc_family
= skb
->sk
->sk_family
;
54 addr
->sllc_arphrd
= skb
->dev
->type
;
55 addr
->sllc_test
= prim
== LLC_TEST_PRIM
;
56 addr
->sllc_xid
= prim
== LLC_XID_PRIM
;
57 addr
->sllc_ua
= prim
== LLC_DATAUNIT_PRIM
;
58 llc_pdu_decode_sa(skb
, addr
->sllc_mac
);
59 llc_pdu_decode_ssap(skb
, &addr
->sllc_sap
);
63 * llc_sap_rtn_pdu - Informs upper layer on rx of an UI, XID or TEST pdu.
64 * @sap: pointer to SAP
67 void llc_sap_rtn_pdu(struct llc_sap
*sap
, struct sk_buff
*skb
)
69 struct llc_sap_state_ev
*ev
= llc_sap_ev(skb
);
70 struct llc_pdu_un
*pdu
= llc_pdu_un_hdr(skb
);
72 switch (LLC_U_PDU_RSP(pdu
)) {
73 case LLC_1_PDU_CMD_TEST
:
74 ev
->prim
= LLC_TEST_PRIM
; break;
75 case LLC_1_PDU_CMD_XID
:
76 ev
->prim
= LLC_XID_PRIM
; break;
77 case LLC_1_PDU_CMD_UI
:
78 ev
->prim
= LLC_DATAUNIT_PRIM
; break;
80 ev
->ind_cfm_flag
= LLC_IND
;
84 * llc_find_sap_trans - finds transition for event
85 * @sap: pointer to SAP
86 * @skb: happened event
88 * This function finds transition that matches with happened event.
89 * Returns the pointer to found transition on success or %NULL for
92 static struct llc_sap_state_trans
*llc_find_sap_trans(struct llc_sap
*sap
,
96 struct llc_sap_state_trans
*rc
= NULL
;
97 struct llc_sap_state_trans
**next_trans
;
98 struct llc_sap_state
*curr_state
= &llc_sap_state_table
[sap
->state
- 1];
100 * Search thru events for this state until list exhausted or until
101 * its obvious the event is not valid for the current state
103 for (next_trans
= curr_state
->transitions
; next_trans
[i
]->ev
; i
++)
104 if (!next_trans
[i
]->ev(sap
, skb
)) {
105 rc
= next_trans
[i
]; /* got event match; return it */
112 * llc_exec_sap_trans_actions - execute actions related to event
113 * @sap: pointer to SAP
114 * @trans: pointer to transition that it's actions must be performed
115 * @skb: happened event.
117 * This function executes actions that is related to happened event.
118 * Returns 0 for success and 1 for failure of at least one action.
120 static int llc_exec_sap_trans_actions(struct llc_sap
*sap
,
121 struct llc_sap_state_trans
*trans
,
125 llc_sap_action_t
*next_action
= trans
->ev_actions
;
127 for (; next_action
&& *next_action
; next_action
++)
128 if ((*next_action
)(sap
, skb
))
134 * llc_sap_next_state - finds transition, execs actions & change SAP state
135 * @sap: pointer to SAP
136 * @skb: happened event
138 * This function finds transition that matches with happened event, then
139 * executes related actions and finally changes state of SAP. It returns
140 * 0 on success and 1 for failure.
142 static int llc_sap_next_state(struct llc_sap
*sap
, struct sk_buff
*skb
)
145 struct llc_sap_state_trans
*trans
;
147 if (sap
->state
> LLC_NR_SAP_STATES
)
149 trans
= llc_find_sap_trans(sap
, skb
);
153 * Got the state to which we next transition; perform the actions
154 * associated with this transition before actually transitioning to the
157 rc
= llc_exec_sap_trans_actions(sap
, trans
, skb
);
161 * Transition SAP to next state if all actions execute successfully
163 sap
->state
= trans
->next_state
;
169 * llc_sap_state_process - sends event to SAP state machine
171 * @skb: pointer to occurred event
173 * After executing actions of the event, upper layer will be indicated
174 * if needed(on receiving an UI frame). sk can be null for the
175 * datalink_proto case.
177 static void llc_sap_state_process(struct llc_sap
*sap
, struct sk_buff
*skb
)
179 struct llc_sap_state_ev
*ev
= llc_sap_ev(skb
);
182 * We have to hold the skb, because llc_sap_next_state
183 * will kfree it in the sending path and we need to
184 * look at the skb->cb, where we encode llc_sap_state_ev.
187 ev
->ind_cfm_flag
= 0;
188 llc_sap_next_state(sap
, skb
);
189 if (ev
->ind_cfm_flag
== LLC_IND
) {
190 if (skb
->sk
->sk_state
== TCP_LISTEN
)
193 llc_save_primitive(skb
, ev
->prim
);
195 /* queue skb to the user. */
196 if (sock_queue_rcv_skb(skb
->sk
, skb
))
204 * llc_build_and_send_test_pkt - TEST interface for upper layers.
206 * @skb: packet to send
207 * @dmac: destination mac address
208 * @dsap: destination sap
210 * This function is called when upper layer wants to send a TEST pdu.
211 * Returns 0 for success, 1 otherwise.
213 void llc_build_and_send_test_pkt(struct llc_sap
*sap
,
214 struct sk_buff
*skb
, u8
*dmac
, u8 dsap
)
216 struct llc_sap_state_ev
*ev
= llc_sap_ev(skb
);
218 ev
->saddr
.lsap
= sap
->laddr
.lsap
;
219 ev
->daddr
.lsap
= dsap
;
220 memcpy(ev
->saddr
.mac
, skb
->dev
->dev_addr
, IFHWADDRLEN
);
221 memcpy(ev
->daddr
.mac
, dmac
, IFHWADDRLEN
);
223 ev
->type
= LLC_SAP_EV_TYPE_PRIM
;
224 ev
->prim
= LLC_TEST_PRIM
;
225 ev
->prim_type
= LLC_PRIM_TYPE_REQ
;
226 llc_sap_state_process(sap
, skb
);
230 * llc_build_and_send_xid_pkt - XID interface for upper layers
232 * @skb: packet to send
233 * @dmac: destination mac address
234 * @dsap: destination sap
236 * This function is called when upper layer wants to send a XID pdu.
237 * Returns 0 for success, 1 otherwise.
239 void llc_build_and_send_xid_pkt(struct llc_sap
*sap
, struct sk_buff
*skb
,
242 struct llc_sap_state_ev
*ev
= llc_sap_ev(skb
);
244 ev
->saddr
.lsap
= sap
->laddr
.lsap
;
245 ev
->daddr
.lsap
= dsap
;
246 memcpy(ev
->saddr
.mac
, skb
->dev
->dev_addr
, IFHWADDRLEN
);
247 memcpy(ev
->daddr
.mac
, dmac
, IFHWADDRLEN
);
249 ev
->type
= LLC_SAP_EV_TYPE_PRIM
;
250 ev
->prim
= LLC_XID_PRIM
;
251 ev
->prim_type
= LLC_PRIM_TYPE_REQ
;
252 llc_sap_state_process(sap
, skb
);
256 * llc_sap_rcv - sends received pdus to the sap state machine
257 * @sap: current sap component structure.
258 * @skb: received frame.
260 * Sends received pdus to the sap state machine.
262 static void llc_sap_rcv(struct llc_sap
*sap
, struct sk_buff
*skb
)
264 struct llc_sap_state_ev
*ev
= llc_sap_ev(skb
);
266 ev
->type
= LLC_SAP_EV_TYPE_PDU
;
268 llc_sap_state_process(sap
, skb
);
272 * llc_lookup_dgram - Finds dgram socket for the local sap/mac
274 * @laddr: address of local LLC (MAC + SAP)
276 * Search socket list of the SAP and finds connection using the local
277 * mac, and local sap. Returns pointer for socket found, %NULL otherwise.
279 static struct sock
*llc_lookup_dgram(struct llc_sap
*sap
,
280 struct llc_addr
*laddr
)
283 struct hlist_node
*node
;
285 read_lock_bh(&sap
->sk_list
.lock
);
286 sk_for_each(rc
, node
, &sap
->sk_list
.list
) {
287 struct llc_sock
*llc
= llc_sk(rc
);
289 if (rc
->sk_type
== SOCK_DGRAM
&&
290 llc
->laddr
.lsap
== laddr
->lsap
&&
291 llc_mac_match(llc
->laddr
.mac
, laddr
->mac
)) {
298 read_unlock_bh(&sap
->sk_list
.lock
);
302 void llc_sap_handler(struct llc_sap
*sap
, struct sk_buff
*skb
)
304 struct llc_addr laddr
;
307 llc_pdu_decode_da(skb
, laddr
.mac
);
308 llc_pdu_decode_dsap(skb
, &laddr
.lsap
);
310 sk
= llc_lookup_dgram(sap
, &laddr
);
313 llc_sap_rcv(sap
, skb
);
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