net/llc/llc_s_ac.c

   1 /*
   2  * llc_s_ac.c - actions performed during sap state transition.
   3  *
   4  * Description :
   5  *   Functions in this module are implementation of sap component actions.
   6  *   Details of actions can be found in IEEE-802.2 standard document.
   7  *   All functions have one sap and one event as input argument. All of
   8  *   them return 0 On success and 1 otherwise.
   9  *
  10  * Copyright (c) 1997 by Procom Technology, Inc.
  11  *               2001-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
  12  *
  13  * This program can be redistributed or modified under the terms of the
  14  * GNU General Public License as published by the Free Software Foundation.
  15  * This program is distributed without any warranty or implied warranty
  16  * of merchantability or fitness for a particular purpose.
  17  *
  18  * See the GNU General Public License for more details.
  19  */
  20
  21 #include <linux/netdevice.h>
  22 #include <net/llc.h>
  23 #include <net/llc_pdu.h>
  24 #include <net/llc_s_ac.h>
  25 #include <net/llc_s_ev.h>
  26 #include <net/llc_sap.h>
  27
  28
  29 /**
  30  *      llc_sap_action_unit_data_ind - forward UI PDU to network layer
  31  *      @sap: SAP
  32  *      @skb: the event to forward
  33  *
  34  *      Received a UI PDU from MAC layer; forward to network layer as a
  35  *      UNITDATA INDICATION; verify our event is the kind we expect
  36  */
  37 int llc_sap_action_unitdata_ind(struct llc_sap *sap, struct sk_buff *skb)
  38 {
  39         llc_sap_rtn_pdu(sap, skb);
  40         return 0;
  41 }
  42
  43 /**
  44  *      llc_sap_action_send_ui - sends UI PDU resp to UNITDATA REQ to MAC layer
  45  *      @sap: SAP
  46  *      @skb: the event to send
  47  *
  48  *      Sends a UI PDU to the MAC layer in response to a UNITDATA REQUEST
  49  *      primitive from the network layer. Verifies event is a primitive type of
  50  *      event. Verify the primitive is a UNITDATA REQUEST.
  51  */
  52 int llc_sap_action_send_ui(struct llc_sap *sap, struct sk_buff *skb)
  53 {
  54         struct llc_sap_state_ev *ev = llc_sap_ev(skb);
  55         int rc;
  56
  57         llc_pdu_header_init(skb, LLC_PDU_TYPE_U, ev->saddr.lsap,
  58                             ev->daddr.lsap, LLC_PDU_CMD);
  59         llc_pdu_init_as_ui_cmd(skb);
  60         rc = llc_mac_hdr_init(skb, ev->saddr.mac, ev->daddr.mac);
  61         if (likely(!rc))
  62                 rc = dev_queue_xmit(skb);
  63         return rc;
  64 }
  65
  66 /**
  67  *      llc_sap_action_send_xid_c - send XID PDU as response to XID REQ
  68  *      @sap: SAP
  69  *      @skb: the event to send
  70  *
  71  *      Send a XID command PDU to MAC layer in response to a XID REQUEST
  72  *      primitive from the network layer. Verify event is a primitive type
  73  *      event. Verify the primitive is a XID REQUEST.
  74  */
  75 int llc_sap_action_send_xid_c(struct llc_sap *sap, struct sk_buff *skb)
  76 {
  77         struct llc_sap_state_ev *ev = llc_sap_ev(skb);
  78         int rc;
  79
  80         llc_pdu_header_init(skb, LLC_PDU_TYPE_U, ev->saddr.lsap,
  81                             ev->daddr.lsap, LLC_PDU_CMD);
  82         llc_pdu_init_as_xid_cmd(skb, LLC_XID_NULL_CLASS_2, 0);
  83         rc = llc_mac_hdr_init(skb, ev->saddr.mac, ev->daddr.mac);
  84         if (likely(!rc))
  85                 rc = dev_queue_xmit(skb);
  86         return rc;
  87 }
  88
  89 /**
  90  *      llc_sap_action_send_xid_r - send XID PDU resp to MAC for received XID
  91  *      @sap: SAP
  92  *      @skb: the event to send
  93  *
  94  *      Send XID response PDU to MAC in response to an earlier received XID
  95  *      command PDU. Verify event is a PDU type event
  96  */
  97 int llc_sap_action_send_xid_r(struct llc_sap *sap, struct sk_buff *skb)
  98 {
  99         u8 mac_da[ETH_ALEN], mac_sa[ETH_ALEN], dsap;
 100         int rc = 1;
 101         struct sk_buff *nskb;
 102
 103         llc_pdu_decode_sa(skb, mac_da);
 104         llc_pdu_decode_da(skb, mac_sa);
 105         llc_pdu_decode_ssap(skb, &dsap);
 106         nskb = llc_alloc_frame(NULL, skb->dev, LLC_PDU_TYPE_U,
 107                                sizeof(struct llc_xid_info));
 108         if (!nskb)
 109                 goto out;
 110         llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap, dsap,
 111                             LLC_PDU_RSP);
 112         llc_pdu_init_as_xid_rsp(nskb, LLC_XID_NULL_CLASS_2, 0);
 113         rc = llc_mac_hdr_init(nskb, mac_sa, mac_da);
 114         if (likely(!rc))
 115                 rc = dev_queue_xmit(nskb);
 116 out:
 117         return rc;
 118 }
 119
 120 /**
 121  *      llc_sap_action_send_test_c - send TEST PDU to MAC in resp to TEST REQ
 122  *      @sap: SAP
 123  *      @skb: the event to send
 124  *
 125  *      Send a TEST command PDU to the MAC layer in response to a TEST REQUEST
 126  *      primitive from the network layer. Verify event is a primitive type
 127  *      event; verify the primitive is a TEST REQUEST.
 128  */
 129 int llc_sap_action_send_test_c(struct llc_sap *sap, struct sk_buff *skb)
 130 {
 131         struct llc_sap_state_ev *ev = llc_sap_ev(skb);
 132         int rc;
 133
 134         llc_pdu_header_init(skb, LLC_PDU_TYPE_U, ev->saddr.lsap,
 135                             ev->daddr.lsap, LLC_PDU_CMD);
 136         llc_pdu_init_as_test_cmd(skb);
 137         rc = llc_mac_hdr_init(skb, ev->saddr.mac, ev->daddr.mac);
 138         if (likely(!rc))
 139                 rc = dev_queue_xmit(skb);
 140         return rc;
 141 }
 142
 143 int llc_sap_action_send_test_r(struct llc_sap *sap, struct sk_buff *skb)
 144 {
 145         u8 mac_da[ETH_ALEN], mac_sa[ETH_ALEN], dsap;
 146         struct sk_buff *nskb;
 147         int rc = 1;
 148         u32 data_size;
 149
 150         llc_pdu_decode_sa(skb, mac_da);
 151         llc_pdu_decode_da(skb, mac_sa);
 152         llc_pdu_decode_ssap(skb, &dsap);
 153
 154         /* The test request command is type U (llc_len = 3) */
 155         data_size = ntohs(eth_hdr(skb)->h_proto) - 3;
 156         nskb = llc_alloc_frame(NULL, skb->dev, LLC_PDU_TYPE_U, data_size);
 157         if (!nskb)
 158                 goto out;
 159         llc_pdu_header_init(nskb, LLC_PDU_TYPE_U, sap->laddr.lsap, dsap,
 160                             LLC_PDU_RSP);
 161         llc_pdu_init_as_test_rsp(nskb, skb);
 162         rc = llc_mac_hdr_init(nskb, mac_sa, mac_da);
 163         if (likely(!rc))
 164                 rc = dev_queue_xmit(nskb);
 165 out:
 166         return rc;
 167 }
 168
 169 /**
 170  *      llc_sap_action_report_status - report data link status to layer mgmt
 171  *      @sap: SAP
 172  *      @skb: the event to send
 173  *
 174  *      Report data link status to layer management. Verify our event is the
 175  *      kind we expect.
 176  */
 177 int llc_sap_action_report_status(struct llc_sap *sap, struct sk_buff *skb)
 178 {
 179         return 0;
 180 }
 181
 182 /**
 183  *      llc_sap_action_xid_ind - send XID PDU resp to net layer via XID IND
 184  *      @sap: SAP
 185  *      @skb: the event to send
 186  *
 187  *      Send a XID response PDU to the network layer via a XID INDICATION
 188  *      primitive.
 189  */
 190 int llc_sap_action_xid_ind(struct llc_sap *sap, struct sk_buff *skb)
 191 {
 192         llc_sap_rtn_pdu(sap, skb);
 193         return 0;
 194 }
 195
 196 /**
 197  *      llc_sap_action_test_ind - send TEST PDU to net layer via TEST IND
 198  *      @sap: SAP
 199  *      @skb: the event to send
 200  *
 201  *      Send a TEST response PDU to the network layer via a TEST INDICATION
 202  *      primitive. Verify our event is a PDU type event.
 203  */
 204 int llc_sap_action_test_ind(struct llc_sap *sap, struct sk_buff *skb)
 205 {
 206         llc_sap_rtn_pdu(sap, skb);
 207         return 0;
 208 }