blob: a89917130a7bd76e4aa9e64c4b2c8a1b78b6723a [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * llc_if.c - Defines LLC interface to upper layer
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 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070014#include <linux/module.h>
15#include <linux/kernel.h>
16#include <linux/netdevice.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#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>
22#include <net/sock.h>
23#include <net/llc_c_ev.h>
24#include <net/llc_c_ac.h>
25#include <net/llc_c_st.h>
Arnaldo Carvalho de Meloc752f072005-08-09 20:08:28 -070026#include <net/tcp_states.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070027
Linus Torvalds1da177e2005-04-16 15:20:36 -070028/**
29 * llc_build_and_send_pkt - Connection data sending for upper layers.
30 * @sk: connection
31 * @skb: packet to send
32 *
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
39 * response.
40 */
41int llc_build_and_send_pkt(struct sock *sk, struct sk_buff *skb)
42{
43 struct llc_conn_state_ev *ev;
44 int rc = -ECONNABORTED;
45 struct llc_sock *llc = llc_sk(sk);
46
Arnaldo Carvalho de Melo249ff1c2005-09-22 04:32:10 -030047 if (unlikely(llc->state == LLC_CONN_STATE_ADM))
Linus Torvalds1da177e2005-04-16 15:20:36 -070048 goto out;
49 rc = -EBUSY;
Arnaldo Carvalho de Melo249ff1c2005-09-22 04:32:10 -030050 if (unlikely(llc_data_accept_state(llc->state) || /* data_conn_refuse */
51 llc->p_flag)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070052 llc->failed_data_req = 1;
53 goto out;
54 }
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;
59 skb->dev = llc->dev;
60 rc = llc_conn_state_process(sk, skb);
61out:
62 return rc;
63}
64
65/**
66 * llc_establish_connection - Called by upper layer to establish a conn
67 * @sk: connection
68 * @lmac: local mac address
69 * @dmac: destination mac address
70 * @dsap: destination sap
71 *
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.
77 */
78int llc_establish_connection(struct sock *sk, u8 *lmac, u8 *dmac, u8 dsap)
79{
80 int rc = -EISCONN;
81 struct llc_addr laddr, daddr;
82 struct sk_buff *skb;
83 struct llc_sock *llc = llc_sk(sk);
84 struct sock *existing;
85
86 laddr.lsap = llc->sap->laddr.lsap;
87 daddr.lsap = dsap;
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);
91 if (existing) {
92 if (existing->sk_state == TCP_ESTABLISHED) {
93 sk = existing;
94 goto out_put;
95 } else
96 sock_put(existing);
97 }
98 sock_hold(sk);
99 rc = -ENOMEM;
100 skb = alloc_skb(0, GFP_ATOMIC);
101 if (skb) {
102 struct llc_conn_state_ev *ev = llc_conn_ev(skb);
103
104 ev->type = LLC_CONN_EV_TYPE_PRIM;
105 ev->prim = LLC_CONN_PRIM;
106 ev->prim_type = LLC_PRIM_TYPE_REQ;
Arnaldo Carvalho de Melod3894242005-09-22 07:57:21 -0300107 skb_set_owner_w(skb, sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108 rc = llc_conn_state_process(sk, skb);
109 }
110out_put:
111 sock_put(sk);
112 return rc;
113}
114
115/**
116 * llc_send_disc - Called by upper layer to close a connection
117 * @sk: connection to be closed
118 *
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.
123 */
124int llc_send_disc(struct sock *sk)
125{
126 u16 rc = 1;
127 struct llc_conn_state_ev *ev;
128 struct sk_buff *skb;
129
130 sock_hold(sk);
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)
134 goto out;
135 /*
136 * Postpone unassigning the connection from its SAP and returning the
137 * connection until all ACTIONs have been completely executed
138 */
139 skb = alloc_skb(0, GFP_ATOMIC);
140 if (!skb)
141 goto out;
Arnaldo Carvalho de Melod3894242005-09-22 07:57:21 -0300142 skb_set_owner_w(skb, sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143 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);
149out:
150 sock_put(sk);
151 return rc;
152}
153