cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

llc_station.c (3269B)

      1/*
      2 * llc_station.c - station component of LLC
      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/init.h>
     15#include <linux/module.h>
     16#include <linux/slab.h>
     17#include <net/llc.h>
     18#include <net/llc_sap.h>
     19#include <net/llc_conn.h>
     20#include <net/llc_c_ac.h>
     21#include <net/llc_s_ac.h>
     22#include <net/llc_c_ev.h>
     23#include <net/llc_c_st.h>
     24#include <net/llc_s_ev.h>
     25#include <net/llc_s_st.h>
     26#include <net/llc_pdu.h>
     27
     28static int llc_stat_ev_rx_null_dsap_xid_c(struct sk_buff *skb)
     29{
     30	struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
     31
     32	return LLC_PDU_IS_CMD(pdu) &&			/* command PDU */
     33	       LLC_PDU_TYPE_IS_U(pdu) &&		/* U type PDU */
     34	       LLC_U_PDU_CMD(pdu) == LLC_1_PDU_CMD_XID &&
     35	       !pdu->dsap;				/* NULL DSAP value */
     36}
     37
     38static int llc_stat_ev_rx_null_dsap_test_c(struct sk_buff *skb)
     39{
     40	struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
     41
     42	return LLC_PDU_IS_CMD(pdu) &&			/* command PDU */
     43	       LLC_PDU_TYPE_IS_U(pdu) &&		/* U type PDU */
     44	       LLC_U_PDU_CMD(pdu) == LLC_1_PDU_CMD_TEST &&
     45	       !pdu->dsap;				/* NULL DSAP */
     46}
     47
     48static int llc_station_ac_send_xid_r(struct sk_buff *skb)
     49{
     50	u8 mac_da[ETH_ALEN], dsap;
     51	int rc = 1;
     52	struct sk_buff *nskb = llc_alloc_frame(NULL, skb->dev, LLC_PDU_TYPE_U,
     53					       sizeof(struct llc_xid_info));
     54
     55	if (!nskb)
     56		goto out;
     57	llc_pdu_decode_sa(skb, mac_da);
     58	llc_pdu_decode_ssap(skb, &dsap);
     59	llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, 0, dsap, LLC_PDU_RSP);
     60	llc_pdu_init_as_xid_rsp(nskb, LLC_XID_NULL_CLASS_2, 127);
     61	rc = llc_mac_hdr_init(nskb, skb->dev->dev_addr, mac_da);
     62	if (unlikely(rc))
     63		goto free;
     64	dev_queue_xmit(nskb);
     65out:
     66	return rc;
     67free:
     68	kfree_skb(nskb);
     69	goto out;
     70}
     71
     72static int llc_station_ac_send_test_r(struct sk_buff *skb)
     73{
     74	u8 mac_da[ETH_ALEN], dsap;
     75	int rc = 1;
     76	u32 data_size;
     77	struct sk_buff *nskb;
     78
     79	/* The test request command is type U (llc_len = 3) */
     80	data_size = ntohs(eth_hdr(skb)->h_proto) - 3;
     81	nskb = llc_alloc_frame(NULL, skb->dev, LLC_PDU_TYPE_U, data_size);
     82
     83	if (!nskb)
     84		goto out;
     85	llc_pdu_decode_sa(skb, mac_da);
     86	llc_pdu_decode_ssap(skb, &dsap);
     87	llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, 0, dsap, LLC_PDU_RSP);
     88	llc_pdu_init_as_test_rsp(nskb, skb);
     89	rc = llc_mac_hdr_init(nskb, skb->dev->dev_addr, mac_da);
     90	if (unlikely(rc))
     91		goto free;
     92	dev_queue_xmit(nskb);
     93out:
     94	return rc;
     95free:
     96	kfree_skb(nskb);
     97	goto out;
     98}
     99
    100/**
    101 *	llc_station_rcv - send received pdu to the station state machine
    102 *	@skb: received frame.
    103 *
    104 *	Sends data unit to station state machine.
    105 */
    106static void llc_station_rcv(struct sk_buff *skb)
    107{
    108	if (llc_stat_ev_rx_null_dsap_xid_c(skb))
    109		llc_station_ac_send_xid_r(skb);
    110	else if (llc_stat_ev_rx_null_dsap_test_c(skb))
    111		llc_station_ac_send_test_r(skb);
    112	kfree_skb(skb);
    113}
    114
    115void __init llc_station_init(void)
    116{
    117	llc_set_station_handler(llc_station_rcv);
    118}
    119
    120void llc_station_exit(void)
    121{
    122	llc_set_station_handler(NULL);
    123}