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