2 * llc_if.c - Defines LLC interface to upper layer
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.
14 #include <linux/module.h>
15 #include <linux/kernel.h>
16 #include <linux/netdevice.h>
17 #include <asm/errno.h>
18 #include <net/llc_if.h>
19 #include <net/llc_sap.h>
20 #include <net/llc_s_ev.h>
21 #include <net/llc_conn.h>
23 #include <net/llc_c_ev.h>
24 #include <net/llc_c_ac.h>
25 #include <net/llc_c_st.h>
26 #include <net/tcp_states.h>
29 * llc_build_and_send_pkt - Connection data sending for upper layers.
31 * @skb: packet to send
33 * This function is called when upper layer wants to send data using
34 * connection oriented communication mode. During sending data, connection
35 * will be locked and received frames and expired timers will be queued.
36 * Returns 0 for success, -ECONNABORTED when the connection already
37 * closed and -EBUSY when sending data is not permitted in this state or
38 * LLC has send an I pdu with p bit set to 1 and is waiting for it's
41 int llc_build_and_send_pkt(struct sock
*sk
, struct sk_buff
*skb
)
43 struct llc_conn_state_ev
*ev
;
44 int rc
= -ECONNABORTED
;
45 struct llc_sock
*llc
= llc_sk(sk
);
47 if (unlikely(llc
->state
== LLC_CONN_STATE_ADM
))
50 if (unlikely(llc_data_accept_state(llc
->state
) || /* data_conn_refuse */
52 llc
->failed_data_req
= 1;
55 ev
= llc_conn_ev(skb
);
56 ev
->type
= LLC_CONN_EV_TYPE_PRIM
;
57 ev
->prim
= LLC_DATA_PRIM
;
58 ev
->prim_type
= LLC_PRIM_TYPE_REQ
;
60 rc
= llc_conn_state_process(sk
, skb
);
66 * llc_establish_connection - Called by upper layer to establish a conn
68 * @lmac: local mac address
69 * @dmac: destination mac address
70 * @dsap: destination sap
72 * Upper layer calls this to establish an LLC connection with a remote
73 * machine. This function packages a proper event and sends it connection
74 * component state machine. Success or failure of connection
75 * establishment will inform to upper layer via calling it's confirm
76 * function and passing proper information.
78 int llc_establish_connection(struct sock
*sk
, u8
*lmac
, u8
*dmac
, u8 dsap
)
81 struct llc_addr laddr
, daddr
;
83 struct llc_sock
*llc
= llc_sk(sk
);
84 struct sock
*existing
;
86 laddr
.lsap
= llc
->sap
->laddr
.lsap
;
88 memcpy(daddr
.mac
, dmac
, sizeof(daddr
.mac
));
89 memcpy(laddr
.mac
, lmac
, sizeof(laddr
.mac
));
90 existing
= llc_lookup_established(llc
->sap
, &daddr
, &laddr
);
92 if (existing
->sk_state
== TCP_ESTABLISHED
) {
100 skb
= alloc_skb(0, GFP_ATOMIC
);
102 struct llc_conn_state_ev
*ev
= llc_conn_ev(skb
);
104 ev
->type
= LLC_CONN_EV_TYPE_PRIM
;
105 ev
->prim
= LLC_CONN_PRIM
;
106 ev
->prim_type
= LLC_PRIM_TYPE_REQ
;
107 skb_set_owner_w(skb
, sk
);
108 rc
= llc_conn_state_process(sk
, skb
);
116 * llc_send_disc - Called by upper layer to close a connection
117 * @sk: connection to be closed
119 * Upper layer calls this when it wants to close an established LLC
120 * connection with a remote machine. This function packages a proper event
121 * and sends it to connection component state machine. Returns 0 for
122 * success, 1 otherwise.
124 int llc_send_disc(struct sock
*sk
)
127 struct llc_conn_state_ev
*ev
;
131 if (sk
->sk_type
!= SOCK_STREAM
|| sk
->sk_state
!= TCP_ESTABLISHED
||
132 llc_sk(sk
)->state
== LLC_CONN_STATE_ADM
||
133 llc_sk(sk
)->state
== LLC_CONN_OUT_OF_SVC
)
136 * Postpone unassigning the connection from its SAP and returning the
137 * connection until all ACTIONs have been completely executed
139 skb
= alloc_skb(0, GFP_ATOMIC
);
142 skb_set_owner_w(skb
, sk
);
143 sk
->sk_state
= TCP_CLOSING
;
144 ev
= llc_conn_ev(skb
);
145 ev
->type
= LLC_CONN_EV_TYPE_PRIM
;
146 ev
->prim
= LLC_DISC_PRIM
;
147 ev
->prim_type
= LLC_PRIM_TYPE_REQ
;
148 rc
= llc_conn_state_process(sk
, skb
);