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157 lines
4.5 KiB
157 lines
4.5 KiB
/* |
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* llc_if.c - Defines LLC interface to upper layer |
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* |
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* Copyright (c) 1997 by Procom Technology, Inc. |
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* 2001-2003 by Arnaldo Carvalho de Melo <[email protected]> |
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* |
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* This program can be redistributed or modified under the terms of the |
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* GNU General Public License as published by the Free Software Foundation. |
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* This program is distributed without any warranty or implied warranty |
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* of merchantability or fitness for a particular purpose. |
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* |
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* See the GNU General Public License for more details. |
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*/ |
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#include <linux/gfp.h> |
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#include <linux/module.h> |
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#include <linux/kernel.h> |
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#include <linux/netdevice.h> |
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#include <linux/errno.h> |
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#include <net/llc_if.h> |
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#include <net/llc_sap.h> |
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#include <net/llc_s_ev.h> |
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#include <net/llc_conn.h> |
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#include <net/sock.h> |
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#include <net/llc_c_ev.h> |
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#include <net/llc_c_ac.h> |
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#include <net/llc_c_st.h> |
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#include <net/tcp_states.h> |
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/** |
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* llc_build_and_send_pkt - Connection data sending for upper layers. |
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* @sk: connection |
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* @skb: packet to send |
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* |
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* This function is called when upper layer wants to send data using |
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* connection oriented communication mode. During sending data, connection |
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* will be locked and received frames and expired timers will be queued. |
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* Returns 0 for success, -ECONNABORTED when the connection already |
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* closed and -EBUSY when sending data is not permitted in this state or |
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* LLC has send an I pdu with p bit set to 1 and is waiting for it's |
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* response. |
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* |
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* This function always consumes a reference to the skb. |
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*/ |
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int llc_build_and_send_pkt(struct sock *sk, struct sk_buff *skb) |
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{ |
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struct llc_conn_state_ev *ev; |
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int rc = -ECONNABORTED; |
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struct llc_sock *llc = llc_sk(sk); |
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if (unlikely(llc->state == LLC_CONN_STATE_ADM)) |
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goto out_free; |
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rc = -EBUSY; |
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if (unlikely(llc_data_accept_state(llc->state) || /* data_conn_refuse */ |
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llc->p_flag)) { |
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llc->failed_data_req = 1; |
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goto out_free; |
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} |
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ev = llc_conn_ev(skb); |
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ev->type = LLC_CONN_EV_TYPE_PRIM; |
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ev->prim = LLC_DATA_PRIM; |
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ev->prim_type = LLC_PRIM_TYPE_REQ; |
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skb->dev = llc->dev; |
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return llc_conn_state_process(sk, skb); |
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out_free: |
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kfree_skb(skb); |
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return rc; |
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} |
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/** |
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* llc_establish_connection - Called by upper layer to establish a conn |
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* @sk: connection |
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* @lmac: local mac address |
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* @dmac: destination mac address |
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* @dsap: destination sap |
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* |
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* Upper layer calls this to establish an LLC connection with a remote |
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* machine. This function packages a proper event and sends it connection |
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* component state machine. Success or failure of connection |
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* establishment will inform to upper layer via calling it's confirm |
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* function and passing proper information. |
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*/ |
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int llc_establish_connection(struct sock *sk, u8 *lmac, u8 *dmac, u8 dsap) |
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{ |
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int rc = -EISCONN; |
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struct llc_addr laddr, daddr; |
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struct sk_buff *skb; |
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struct llc_sock *llc = llc_sk(sk); |
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struct sock *existing; |
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laddr.lsap = llc->sap->laddr.lsap; |
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daddr.lsap = dsap; |
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memcpy(daddr.mac, dmac, sizeof(daddr.mac)); |
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memcpy(laddr.mac, lmac, sizeof(laddr.mac)); |
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existing = llc_lookup_established(llc->sap, &daddr, &laddr); |
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if (existing) { |
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if (existing->sk_state == TCP_ESTABLISHED) { |
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sk = existing; |
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goto out_put; |
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} else |
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sock_put(existing); |
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} |
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sock_hold(sk); |
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rc = -ENOMEM; |
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skb = alloc_skb(0, GFP_ATOMIC); |
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if (skb) { |
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struct llc_conn_state_ev *ev = llc_conn_ev(skb); |
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ev->type = LLC_CONN_EV_TYPE_PRIM; |
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ev->prim = LLC_CONN_PRIM; |
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ev->prim_type = LLC_PRIM_TYPE_REQ; |
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skb_set_owner_w(skb, sk); |
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rc = llc_conn_state_process(sk, skb); |
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} |
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out_put: |
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sock_put(sk); |
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return rc; |
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} |
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/** |
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* llc_send_disc - Called by upper layer to close a connection |
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* @sk: connection to be closed |
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* |
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* Upper layer calls this when it wants to close an established LLC |
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* connection with a remote machine. This function packages a proper event |
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* and sends it to connection component state machine. Returns 0 for |
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* success, 1 otherwise. |
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*/ |
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int llc_send_disc(struct sock *sk) |
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{ |
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u16 rc = 1; |
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struct llc_conn_state_ev *ev; |
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struct sk_buff *skb; |
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sock_hold(sk); |
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if (sk->sk_type != SOCK_STREAM || sk->sk_state != TCP_ESTABLISHED || |
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llc_sk(sk)->state == LLC_CONN_STATE_ADM || |
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llc_sk(sk)->state == LLC_CONN_OUT_OF_SVC) |
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goto out; |
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/* |
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* Postpone unassigning the connection from its SAP and returning the |
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* connection until all ACTIONs have been completely executed |
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*/ |
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skb = alloc_skb(0, GFP_ATOMIC); |
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if (!skb) |
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goto out; |
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skb_set_owner_w(skb, sk); |
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sk->sk_state = TCP_CLOSING; |
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ev = llc_conn_ev(skb); |
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ev->type = LLC_CONN_EV_TYPE_PRIM; |
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ev->prim = LLC_DISC_PRIM; |
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ev->prim_type = LLC_PRIM_TYPE_REQ; |
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rc = llc_conn_state_process(sk, skb); |
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out: |
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sock_put(sk); |
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return rc; |
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}
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