diff options
Diffstat (limited to 'net/llc/llc_if.c')
| -rw-r--r-- | net/llc/llc_if.c | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/net/llc/llc_if.c b/net/llc/llc_if.c new file mode 100644 index 000000000..ad6547736 --- /dev/null +++ b/net/llc/llc_if.c @@ -0,0 +1,157 @@ +/* + * 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. + * + * This function always consumes a reference to the skb. + */ +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_free; + rc = -EBUSY; + if (unlikely(llc_data_accept_state(llc->state) || /* data_conn_refuse */ + llc->p_flag)) { + llc->failed_data_req = 1; + goto out_free; + } + 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; + return llc_conn_state_process(sk, skb); + +out_free: + kfree_skb(skb); + 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; +} |