blob: ba90f7f0801ad5fbe9006a3da96234a71b6b7042 [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 */
14#include <linux/config.h>
15#include <linux/module.h>
16#include <linux/kernel.h>
17#include <linux/netdevice.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070018#include <asm/errno.h>
19#include <net/llc_if.h>
20#include <net/llc_sap.h>
21#include <net/llc_s_ev.h>
22#include <net/llc_conn.h>
23#include <net/sock.h>
24#include <net/llc_c_ev.h>
25#include <net/llc_c_ac.h>
26#include <net/llc_c_st.h>
Arnaldo Carvalho de Meloc752f072005-08-09 20:08:28 -070027#include <net/tcp_states.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070028
29u8 llc_mac_null_var[IFHWADDRLEN];
30
31/**
32 * llc_build_and_send_pkt - Connection data sending for upper layers.
33 * @sk: connection
34 * @skb: packet to send
35 *
36 * This function is called when upper layer wants to send data using
37 * connection oriented communication mode. During sending data, connection
38 * will be locked and received frames and expired timers will be queued.
39 * Returns 0 for success, -ECONNABORTED when the connection already
40 * closed and -EBUSY when sending data is not permitted in this state or
41 * LLC has send an I pdu with p bit set to 1 and is waiting for it's
42 * response.
43 */
44int llc_build_and_send_pkt(struct sock *sk, struct sk_buff *skb)
45{
46 struct llc_conn_state_ev *ev;
47 int rc = -ECONNABORTED;
48 struct llc_sock *llc = llc_sk(sk);
49
Arnaldo Carvalho de Melo249ff1c2005-09-22 04:32:10 -030050 if (unlikely(llc->state == LLC_CONN_STATE_ADM))
Linus Torvalds1da177e2005-04-16 15:20:36 -070051 goto out;
52 rc = -EBUSY;
Arnaldo Carvalho de Melo249ff1c2005-09-22 04:32:10 -030053 if (unlikely(llc_data_accept_state(llc->state) || /* data_conn_refuse */
54 llc->p_flag)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070055 llc->failed_data_req = 1;
56 goto out;
57 }
58 ev = llc_conn_ev(skb);
59 ev->type = LLC_CONN_EV_TYPE_PRIM;
60 ev->prim = LLC_DATA_PRIM;
61 ev->prim_type = LLC_PRIM_TYPE_REQ;
62 skb->dev = llc->dev;
63 rc = llc_conn_state_process(sk, skb);
64out:
65 return rc;
66}
67
68/**
69 * llc_establish_connection - Called by upper layer to establish a conn
70 * @sk: connection
71 * @lmac: local mac address
72 * @dmac: destination mac address
73 * @dsap: destination sap
74 *
75 * Upper layer calls this to establish an LLC connection with a remote
76 * machine. This function packages a proper event and sends it connection
77 * component state machine. Success or failure of connection
78 * establishment will inform to upper layer via calling it's confirm
79 * function and passing proper information.
80 */
81int llc_establish_connection(struct sock *sk, u8 *lmac, u8 *dmac, u8 dsap)
82{
83 int rc = -EISCONN;
84 struct llc_addr laddr, daddr;
85 struct sk_buff *skb;
86 struct llc_sock *llc = llc_sk(sk);
87 struct sock *existing;
88
89 laddr.lsap = llc->sap->laddr.lsap;
90 daddr.lsap = dsap;
91 memcpy(daddr.mac, dmac, sizeof(daddr.mac));
92 memcpy(laddr.mac, lmac, sizeof(laddr.mac));
93 existing = llc_lookup_established(llc->sap, &daddr, &laddr);
94 if (existing) {
95 if (existing->sk_state == TCP_ESTABLISHED) {
96 sk = existing;
97 goto out_put;
98 } else
99 sock_put(existing);
100 }
101 sock_hold(sk);
102 rc = -ENOMEM;
103 skb = alloc_skb(0, GFP_ATOMIC);
104 if (skb) {
105 struct llc_conn_state_ev *ev = llc_conn_ev(skb);
106
107 ev->type = LLC_CONN_EV_TYPE_PRIM;
108 ev->prim = LLC_CONN_PRIM;
109 ev->prim_type = LLC_PRIM_TYPE_REQ;
Arnaldo Carvalho de Melod3894242005-09-22 07:57:21 -0300110 skb_set_owner_w(skb, sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111 rc = llc_conn_state_process(sk, skb);
112 }
113out_put:
114 sock_put(sk);
115 return rc;
116}
117
118/**
119 * llc_send_disc - Called by upper layer to close a connection
120 * @sk: connection to be closed
121 *
122 * Upper layer calls this when it wants to close an established LLC
123 * connection with a remote machine. This function packages a proper event
124 * and sends it to connection component state machine. Returns 0 for
125 * success, 1 otherwise.
126 */
127int llc_send_disc(struct sock *sk)
128{
129 u16 rc = 1;
130 struct llc_conn_state_ev *ev;
131 struct sk_buff *skb;
132
133 sock_hold(sk);
134 if (sk->sk_type != SOCK_STREAM || sk->sk_state != TCP_ESTABLISHED ||
135 llc_sk(sk)->state == LLC_CONN_STATE_ADM ||
136 llc_sk(sk)->state == LLC_CONN_OUT_OF_SVC)
137 goto out;
138 /*
139 * Postpone unassigning the connection from its SAP and returning the
140 * connection until all ACTIONs have been completely executed
141 */
142 skb = alloc_skb(0, GFP_ATOMIC);
143 if (!skb)
144 goto out;
Arnaldo Carvalho de Melod3894242005-09-22 07:57:21 -0300145 skb_set_owner_w(skb, sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146 sk->sk_state = TCP_CLOSING;
147 ev = llc_conn_ev(skb);
148 ev->type = LLC_CONN_EV_TYPE_PRIM;
149 ev->prim = LLC_DISC_PRIM;
150 ev->prim_type = LLC_PRIM_TYPE_REQ;
151 rc = llc_conn_state_process(sk, skb);
152out:
153 sock_put(sk);
154 return rc;
155}
156