/* * llc_c_ev.c - Connection component state transition event qualifiers * * A 'state' consists of a number of possible event matching functions, * the actions associated with each being executed when that event is * matched; a 'state machine' accepts events in a serial fashion from an * event queue. Each event is passed to each successive event matching * function until a match is made (the event matching function returns * success, or '0') or the list of event matching functions is exhausted. * If a match is made, the actions associated with the event are executed * and the state is changed to that event's transition state. Before some * events are recognized, even after a match has been made, a certain * number of 'event qualifier' functions must also be executed. If these * all execute successfully, then the event is finally executed. * * These event functions must return 0 for success, to show a matched * event, of 1 if the event does not match. Event qualifier functions * must return a 0 for success or a non-zero for failure. Each function * is simply responsible for verifying one single thing and returning * either a success or failure. * * All of followed event functions are described in 802.2 LLC Protocol * standard document except two functions that we added that will explain * in their comments, at below. * * 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/netdevice.h>#include <net/llc_conn.h>#include <net/llc_sap.h>#include <net/sock.h>#include <net/llc_c_ac.h>#include <net/llc_c_ev.h>#include <net/llc_pdu.h>#if 1#define dprintk(args...) printk(KERN_DEBUG args)#else#define dprintk(args...)#endif/** *	llc_util_ns_inside_rx_window - check if sequence number is in rx window *	@ns: sequence number of received pdu. *	@vr: sequence number which receiver expects to receive. *	@rw: receive window size of receiver. * *	Checks if sequence number of received PDU is in range of receive *	window. Returns 0 for success, 1 otherwise */static u16 llc_util_ns_inside_rx_window(u8 ns, u8 vr, u8 rw){	return !llc_circular_between(vr, ns,				     (vr + rw - 1) % LLC_2_SEQ_NBR_MODULO);}/** *	llc_util_nr_inside_tx_window - check if sequence number is in tx window *	@sk: current connection. *	@nr: N(R) of received PDU. * *	This routine checks if N(R) of received PDU is in range of transmit *	window; on the other hand checks if received PDU acknowledges some *	outstanding PDUs that are in transmit window. Returns 0 for success, 1 *	otherwise. */static u16 llc_util_nr_inside_tx_window(struct sock *sk, u8 nr){	u8 nr1, nr2;	struct sk_buff *skb;	struct llc_pdu_sn *pdu;	struct llc_sock *llc = llc_sk(sk);	int rc = 0;	if (llc->dev->flags & IFF_LOOPBACK)		goto out;	rc = 1;	if (skb_queue_empty(&llc->pdu_unack_q))		goto out;	skb = skb_peek(&llc->pdu_unack_q);	pdu = llc_pdu_sn_hdr(skb);	nr1 = LLC_I_GET_NS(pdu);	skb = skb_peek_tail(&llc->pdu_unack_q);	pdu = llc_pdu_sn_hdr(skb);	nr2 = LLC_I_GET_NS(pdu);	rc = !llc_circular_between(nr1, nr, (nr2 + 1) % LLC_2_SEQ_NBR_MODULO);out:	return rc;}int llc_conn_ev_conn_req(struct sock *sk, struct sk_buff *skb){	const struct llc_conn_state_ev *ev = llc_conn_ev(skb);	return ev->prim == LLC_CONN_PRIM &&	       ev->prim_type == LLC_PRIM_TYPE_REQ ? 0 : 1;}int llc_conn_ev_data_req(struct sock *sk, struct sk_buff *skb){	const struct llc_conn_state_ev *ev = llc_conn_ev(skb);	return ev->prim == LLC_DATA_PRIM &&	       ev->prim_type == LLC_PRIM_TYPE_REQ ? 0 : 1;}int llc_conn_ev_disc_req(struct sock *sk, struct sk_buff *skb){	const struct llc_conn_state_ev *ev = llc_conn_ev(skb);	return ev->prim == LLC_DISC_PRIM &&	       ev->prim_type == LLC_PRIM_TYPE_REQ ? 0 : 1;}int llc_conn_ev_rst_req(struct sock *sk, struct sk_buff *skb){	const struct llc_conn_state_ev *ev = llc_conn_ev(skb);	return ev->prim == LLC_RESET_PRIM &&	       ev->prim_type == LLC_PRIM_TYPE_REQ ? 0 : 1;}int llc_conn_ev_local_busy_detected(struct sock *sk, struct sk_buff *skb){	const struct llc_conn_state_ev *ev = llc_conn_ev(skb);	return ev->type == LLC_CONN_EV_TYPE_SIMPLE &&	       ev->prim_type == LLC_CONN_EV_LOCAL_BUSY_DETECTED ? 0 : 1;}int llc_conn_ev_local_busy_cleared(struct sock *sk, struct sk_buff *skb){	const struct llc_conn_state_ev *ev = llc_conn_ev(skb);	return ev->type == LLC_CONN_EV_TYPE_SIMPLE &&	       ev->prim_type == LLC_CONN_EV_LOCAL_BUSY_CLEARED ? 0 : 1;}int llc_conn_ev_rx_bad_pdu(struct sock *sk, struct sk_buff *skb){	return 1;}int llc_conn_ev_rx_disc_cmd_pbit_set_x(struct sock *sk, struct sk_buff *skb){	const struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);	return LLC_PDU_IS_CMD(pdu) && LLC_PDU_TYPE_IS_U(pdu) &&	       LLC_U_PDU_CMD(pdu) == LLC_2_PDU_CMD_DISC ? 0 : 1;}int llc_conn_ev_rx_dm_rsp_fbit_set_x(struct sock *sk, struct sk_buff *skb){	const struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);	return LLC_PDU_IS_RSP(pdu) && LLC_PDU_TYPE_IS_U(pdu) &&	       LLC_U_PDU_RSP(pdu) == LLC_2_PDU_RSP_DM ? 0 : 1;}int llc_conn_ev_rx_frmr_rsp_fbit_set_x(struct sock *sk, struct sk_buff *skb){	const struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);	return LLC_PDU_IS_RSP(pdu) && LLC_PDU_TYPE_IS_U(pdu) &&	       LLC_U_PDU_RSP(pdu) == LLC_2_PDU_RSP_FRMR ? 0 : 1;}int llc_conn_ev_rx_i_cmd_pbit_set_0(struct sock *sk, struct sk_buff *skb){	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);	return llc_conn_space(sk, skb) &&	       LLC_PDU_IS_CMD(pdu) && LLC_PDU_TYPE_IS_I(pdu) &&	       LLC_I_PF_IS_0(pdu) &&	       LLC_I_GET_NS(pdu) == llc_sk(sk)->vR ? 0 : 1;}int llc_conn_ev_rx_i_cmd_pbit_set_1(struct sock *sk, struct sk_buff *skb){	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);	return llc_conn_space(sk, skb) &&	       LLC_PDU_IS_CMD(pdu) && LLC_PDU_TYPE_IS_I(pdu) &&	       LLC_I_PF_IS_1(pdu) &&	       LLC_I_GET_NS(pdu) == llc_sk(sk)->vR ? 0 : 1;}int llc_conn_ev_rx_i_cmd_pbit_set_0_unexpd_ns(struct sock *sk,					      struct sk_buff *skb){	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);	const u8 vr = llc_sk(sk)->vR;	const u8 ns = LLC_I_GET_NS(pdu);	return LLC_PDU_IS_CMD(pdu) && LLC_PDU_TYPE_IS_I(pdu) &&	       LLC_I_PF_IS_0(pdu) && ns != vr &&	       !llc_util_ns_inside_rx_window(ns, vr, llc_sk(sk)->rw) ? 0 : 1;}int llc_conn_ev_rx_i_cmd_pbit_set_1_unexpd_ns(struct sock *sk,					      struct sk_buff *skb){	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);	const u8 vr = llc_sk(sk)->vR;	const u8 ns = LLC_I_GET_NS(pdu);	return LLC_PDU_IS_CMD(pdu) && LLC_PDU_TYPE_IS_I(pdu) &&	       LLC_I_PF_IS_1(pdu) && ns != vr &&	       !llc_util_ns_inside_rx_window(ns, vr, llc_sk(sk)->rw) ? 0 : 1;}int llc_conn_ev_rx_i_cmd_pbit_set_x_inval_ns(struct sock *sk,					     struct sk_buff *skb){	const struct llc_pdu_sn * pdu = llc_pdu_sn_hdr(skb);	const u8 vr = llc_sk(sk)->vR;	const u8 ns = LLC_I_GET_NS(pdu);	const u16 rc = LLC_PDU_IS_CMD(pdu) && LLC_PDU_TYPE_IS_I(pdu) &&		ns != vr &&		 llc_util_ns_inside_rx_window(ns, vr, llc_sk(sk)->rw) ? 0 : 1;	if (!rc)		dprintk("%s: matched, state=%d, ns=%d, vr=%d\n",			__FUNCTION__, llc_sk(sk)->state, ns, vr);	return rc;}int llc_conn_ev_rx_i_rsp_fbit_set_0(struct sock *sk, struct sk_buff *skb){	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);	return llc_conn_space(sk, skb) &&	       LLC_PDU_IS_RSP(pdu) && LLC_PDU_TYPE_IS_I(pdu) &&	       LLC_I_PF_IS_0(pdu) &&	       LLC_I_GET_NS(pdu) == llc_sk(sk)->vR ? 0 : 1;}int llc_conn_ev_rx_i_rsp_fbit_set_1(struct sock *sk, struct sk_buff *skb){	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);	return LLC_PDU_IS_RSP(pdu) && LLC_PDU_TYPE_IS_I(pdu) &&	       LLC_I_PF_IS_1(pdu) &&	       LLC_I_GET_NS(pdu) == llc_sk(sk)->vR ? 0 : 1;}int llc_conn_ev_rx_i_rsp_fbit_set_x(struct sock *sk, struct sk_buff *skb){	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);	return llc_conn_space(sk, skb) &&	       LLC_PDU_IS_RSP(pdu) && LLC_PDU_TYPE_IS_I(pdu) &&	       LLC_I_GET_NS(pdu) == llc_sk(sk)->vR ? 0 : 1;}int llc_conn_ev_rx_i_rsp_fbit_set_0_unexpd_ns(struct sock *sk,					      struct sk_buff *skb){	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);	const u8 vr = llc_sk(sk)->vR;	const u8 ns = LLC_I_GET_NS(pdu);	return LLC_PDU_IS_RSP(pdu) && LLC_PDU_TYPE_IS_I(pdu) &&	       LLC_I_PF_IS_0(pdu) && ns != vr &&	       !llc_util_ns_inside_rx_window(ns, vr, llc_sk(sk)->rw) ? 0 : 1;}int llc_conn_ev_rx_i_rsp_fbit_set_1_unexpd_ns(struct sock *sk,					      struct sk_buff *skb){	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);	const u8 vr = llc_sk(sk)->vR;	const u8 ns = LLC_I_GET_NS(pdu);	return LLC_PDU_IS_RSP(pdu) && LLC_PDU_TYPE_IS_I(pdu) &&	       LLC_I_PF_IS_1(pdu) && ns != vr &&	       !llc_util_ns_inside_rx_window(ns, vr, llc_sk(sk)->rw) ? 0 : 1;}int llc_conn_ev_rx_i_rsp_fbit_set_x_unexpd_ns(struct sock *sk,					      struct sk_buff *skb){	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);	const u8 vr = llc_sk(sk)->vR;	const u8 ns = LLC_I_GET_NS(pdu);	return LLC_PDU_IS_RSP(pdu) && LLC_PDU_TYPE_IS_I(pdu) && ns != vr &&	       !llc_util_ns_inside_rx_window(ns, vr, llc_sk(sk)->rw) ? 0 : 1;}int llc_conn_ev_rx_i_rsp_fbit_set_x_inval_ns(struct sock *sk,					     struct sk_buff *skb){	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);	const u8 vr = llc_sk(sk)->vR;	const u8 ns = LLC_I_GET_NS(pdu);	const u16 rc = LLC_PDU_IS_RSP(pdu) && LLC_PDU_TYPE_IS_I(pdu) &&		ns != vr &&		 llc_util_ns_inside_rx_window(ns, vr, llc_sk(sk)->rw) ? 0 : 1;	if (!rc)		dprintk("%s: matched, state=%d, ns=%d, vr=%d\n",			__FUNCTION__, llc_sk(sk)->state, ns, vr);	return rc;}int llc_conn_ev_rx_rej_cmd_pbit_set_0(struct sock *sk, struct sk_buff *skb){	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);	return LLC_PDU_IS_CMD(pdu) && LLC_PDU_TYPE_IS_S(pdu) &&	       LLC_S_PF_IS_0(pdu) &&	       LLC_S_PDU_CMD(pdu) == LLC_2_PDU_CMD_REJ ? 0 : 1;}int llc_conn_ev_rx_rej_cmd_pbit_set_1(struct sock *sk, struct sk_buff *skb){	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);	return LLC_PDU_IS_CMD(pdu) && LLC_PDU_TYPE_IS_S(pdu) &&	       LLC_S_PF_IS_1(pdu) &&	       LLC_S_PDU_CMD(pdu) == LLC_2_PDU_CMD_REJ ? 0 : 1;}int llc_conn_ev_rx_rej_rsp_fbit_set_0(struct sock *sk, struct sk_buff *skb){	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);	return LLC_PDU_IS_RSP(pdu) && LLC_PDU_TYPE_IS_S(pdu) &&	       LLC_S_PF_IS_0(pdu) &&	       LLC_S_PDU_RSP(pdu) == LLC_2_PDU_RSP_REJ ? 0 : 1;}int llc_conn_ev_rx_rej_rsp_fbit_set_1(struct sock *sk, struct sk_buff *skb){	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);	return LLC_PDU_IS_RSP(pdu) && LLC_PDU_TYPE_IS_S(pdu) &&	       LLC_S_PF_IS_1(pdu) &&	       LLC_S_PDU_RSP(pdu) == LLC_2_PDU_RSP_REJ ? 0 : 1;}int llc_conn_ev_rx_rej_rsp_fbit_set_x(struct sock *sk, struct sk_buff *skb){	const struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);	return LLC_PDU_IS_RSP(pdu) && LLC_PDU_TYPE_IS_S(pdu) &&	       LLC_S_PDU_RSP(pdu) == LLC_2_PDU_RSP_REJ ? 0 : 1;}int llc_conn_ev_rx_rnr_cmd_pbit_set_0(struct sock *sk, struct sk_buff *skb){	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);	return LLC_PDU_IS_CMD(pdu) && LLC_PDU_TYPE_IS_S(pdu) &&	       LLC_S_PF_IS_0(pdu) &&	       LLC_S_PDU_CMD(pdu) == LLC_2_PDU_CMD_RNR ? 0 : 1;}int llc_conn_ev_rx_rnr_cmd_pbit_set_1(struct sock *sk, struct sk_buff *skb){	const struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);	return LLC_PDU_IS_CMD(pdu) && LLC_PDU_TYPE_IS_S(pdu) &&	       LLC_S_PF_IS_1(pdu) &&	       LLC_S_PDU_CMD(pdu) == LLC_2_PDU_CMD_RNR ? 0 : 1;}int llc_conn_ev_rx_rnr_rsp_fbit_set_0(struct sock *sk, struct sk_buff *skb)