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git.proxmox.com Git - mirror_ubuntu-zesty-kernel.git/blob - net/llc/llc_sap.c
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
);
40 skb
->nh
.raw
= skb
->h
.raw
= skb
->data
;
41 skb
->protocol
= htons(ETH_P_802_2
);
43 skb
->mac
.raw
= skb
->head
;
45 skb_set_owner_w(skb
, sk
);
50 void llc_save_primitive(struct sock
*sk
, struct sk_buff
* skb
, u8 prim
)
52 struct sockaddr_llc
*addr
;
54 if (skb
->sk
->sk_type
== SOCK_STREAM
) /* See UNIX98 */
56 /* save primitive for use by the user. */
57 addr
= llc_ui_skb_cb(skb
);
58 addr
->sllc_family
= sk
->sk_family
;
59 addr
->sllc_arphrd
= skb
->dev
->type
;
60 addr
->sllc_test
= prim
== LLC_TEST_PRIM
;
61 addr
->sllc_xid
= prim
== LLC_XID_PRIM
;
62 addr
->sllc_ua
= prim
== LLC_DATAUNIT_PRIM
;
63 llc_pdu_decode_sa(skb
, addr
->sllc_mac
);
64 llc_pdu_decode_ssap(skb
, &addr
->sllc_sap
);
68 * llc_sap_rtn_pdu - Informs upper layer on rx of an UI, XID or TEST pdu.
69 * @sap: pointer to SAP
72 void llc_sap_rtn_pdu(struct llc_sap
*sap
, struct sk_buff
*skb
)
74 struct llc_sap_state_ev
*ev
= llc_sap_ev(skb
);
75 struct llc_pdu_un
*pdu
= llc_pdu_un_hdr(skb
);
77 switch (LLC_U_PDU_RSP(pdu
)) {
78 case LLC_1_PDU_CMD_TEST
:
79 ev
->prim
= LLC_TEST_PRIM
; break;
80 case LLC_1_PDU_CMD_XID
:
81 ev
->prim
= LLC_XID_PRIM
; break;
82 case LLC_1_PDU_CMD_UI
:
83 ev
->prim
= LLC_DATAUNIT_PRIM
; break;
85 ev
->ind_cfm_flag
= LLC_IND
;
89 * llc_find_sap_trans - finds transition for event
90 * @sap: pointer to SAP
91 * @skb: happened event
93 * This function finds transition that matches with happened event.
94 * Returns the pointer to found transition on success or %NULL for
97 static struct llc_sap_state_trans
*llc_find_sap_trans(struct llc_sap
*sap
,
101 struct llc_sap_state_trans
*rc
= NULL
;
102 struct llc_sap_state_trans
**next_trans
;
103 struct llc_sap_state
*curr_state
= &llc_sap_state_table
[sap
->state
- 1];
105 * Search thru events for this state until list exhausted or until
106 * its obvious the event is not valid for the current state
108 for (next_trans
= curr_state
->transitions
; next_trans
[i
]->ev
; i
++)
109 if (!next_trans
[i
]->ev(sap
, skb
)) {
110 rc
= next_trans
[i
]; /* got event match; return it */
117 * llc_exec_sap_trans_actions - execute actions related to event
118 * @sap: pointer to SAP
119 * @trans: pointer to transition that it's actions must be performed
120 * @skb: happened event.
122 * This function executes actions that is related to happened event.
123 * Returns 0 for success and 1 for failure of at least one action.
125 static int llc_exec_sap_trans_actions(struct llc_sap
*sap
,
126 struct llc_sap_state_trans
*trans
,
130 llc_sap_action_t
*next_action
= trans
->ev_actions
;
132 for (; next_action
&& *next_action
; next_action
++)
133 if ((*next_action
)(sap
, skb
))
139 * llc_sap_next_state - finds transition, execs actions & change SAP state
140 * @sap: pointer to SAP
141 * @skb: happened event
143 * This function finds transition that matches with happened event, then
144 * executes related actions and finally changes state of SAP. It returns
145 * 0 on success and 1 for failure.
147 static int llc_sap_next_state(struct llc_sap
*sap
, struct sk_buff
*skb
)
150 struct llc_sap_state_trans
*trans
;
152 if (sap
->state
> LLC_NR_SAP_STATES
)
154 trans
= llc_find_sap_trans(sap
, skb
);
158 * Got the state to which we next transition; perform the actions
159 * associated with this transition before actually transitioning to the
162 rc
= llc_exec_sap_trans_actions(sap
, trans
, skb
);
166 * Transition SAP to next state if all actions execute successfully
168 sap
->state
= trans
->next_state
;
174 * llc_sap_state_process - sends event to SAP state machine
176 * @skb: pointer to occurred event
178 * After executing actions of the event, upper layer will be indicated
179 * if needed(on receiving an UI frame). sk can be null for the
180 * datalink_proto case.
182 static void llc_sap_state_process(struct llc_sap
*sap
, struct sk_buff
*skb
)
184 struct llc_sap_state_ev
*ev
= llc_sap_ev(skb
);
187 * We have to hold the skb, because llc_sap_next_state
188 * will kfree it in the sending path and we need to
189 * look at the skb->cb, where we encode llc_sap_state_ev.
192 ev
->ind_cfm_flag
= 0;
193 llc_sap_next_state(sap
, skb
);
194 if (ev
->ind_cfm_flag
== LLC_IND
) {
195 if (skb
->sk
->sk_state
== TCP_LISTEN
)
198 llc_save_primitive(skb
->sk
, skb
, ev
->prim
);
200 /* queue skb to the user. */
201 if (sock_queue_rcv_skb(skb
->sk
, skb
))
209 * llc_build_and_send_test_pkt - TEST interface for upper layers.
211 * @skb: packet to send
212 * @dmac: destination mac address
213 * @dsap: destination sap
215 * This function is called when upper layer wants to send a TEST pdu.
216 * Returns 0 for success, 1 otherwise.
218 void llc_build_and_send_test_pkt(struct llc_sap
*sap
,
219 struct sk_buff
*skb
, u8
*dmac
, u8 dsap
)
221 struct llc_sap_state_ev
*ev
= llc_sap_ev(skb
);
223 ev
->saddr
.lsap
= sap
->laddr
.lsap
;
224 ev
->daddr
.lsap
= dsap
;
225 memcpy(ev
->saddr
.mac
, skb
->dev
->dev_addr
, IFHWADDRLEN
);
226 memcpy(ev
->daddr
.mac
, dmac
, IFHWADDRLEN
);
228 ev
->type
= LLC_SAP_EV_TYPE_PRIM
;
229 ev
->prim
= LLC_TEST_PRIM
;
230 ev
->prim_type
= LLC_PRIM_TYPE_REQ
;
231 llc_sap_state_process(sap
, skb
);
235 * llc_build_and_send_xid_pkt - XID interface for upper layers
237 * @skb: packet to send
238 * @dmac: destination mac address
239 * @dsap: destination sap
241 * This function is called when upper layer wants to send a XID pdu.
242 * Returns 0 for success, 1 otherwise.
244 void llc_build_and_send_xid_pkt(struct llc_sap
*sap
, struct sk_buff
*skb
,
247 struct llc_sap_state_ev
*ev
= llc_sap_ev(skb
);
249 ev
->saddr
.lsap
= sap
->laddr
.lsap
;
250 ev
->daddr
.lsap
= dsap
;
251 memcpy(ev
->saddr
.mac
, skb
->dev
->dev_addr
, IFHWADDRLEN
);
252 memcpy(ev
->daddr
.mac
, dmac
, IFHWADDRLEN
);
254 ev
->type
= LLC_SAP_EV_TYPE_PRIM
;
255 ev
->prim
= LLC_XID_PRIM
;
256 ev
->prim_type
= LLC_PRIM_TYPE_REQ
;
257 llc_sap_state_process(sap
, skb
);
261 * llc_sap_rcv - sends received pdus to the sap state machine
262 * @sap: current sap component structure.
263 * @skb: received frame.
265 * Sends received pdus to the sap state machine.
267 static void llc_sap_rcv(struct llc_sap
*sap
, struct sk_buff
*skb
)
269 struct llc_sap_state_ev
*ev
= llc_sap_ev(skb
);
271 ev
->type
= LLC_SAP_EV_TYPE_PDU
;
273 llc_sap_state_process(sap
, skb
);
277 * llc_lookup_dgram - Finds dgram socket for the local sap/mac
279 * @laddr: address of local LLC (MAC + SAP)
281 * Search socket list of the SAP and finds connection using the local
282 * mac, and local sap. Returns pointer for socket found, %NULL otherwise.
284 static struct sock
*llc_lookup_dgram(struct llc_sap
*sap
,
285 struct llc_addr
*laddr
)
288 struct hlist_node
*node
;
290 read_lock_bh(&sap
->sk_list
.lock
);
291 sk_for_each(rc
, node
, &sap
->sk_list
.list
) {
292 struct llc_sock
*llc
= llc_sk(rc
);
294 if (rc
->sk_type
== SOCK_DGRAM
&&
295 llc
->laddr
.lsap
== laddr
->lsap
&&
296 llc_mac_match(llc
->laddr
.mac
, laddr
->mac
)) {
303 read_unlock_bh(&sap
->sk_list
.lock
);
307 void llc_sap_handler(struct llc_sap
*sap
, struct sk_buff
*skb
)
309 struct llc_addr laddr
;
312 llc_pdu_decode_da(skb
, laddr
.mac
);
313 llc_pdu_decode_dsap(skb
, &laddr
.lsap
);
315 sk
= llc_lookup_dgram(sap
, &laddr
);
317 skb_set_owner_r(skb
, sk
);
318 llc_sap_rcv(sap
, skb
);