1 /* 2 * llc_output.c - LLC minimal output path 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 version 2 as published by the Free Software 9 * Foundation. 10 * This program is distributed without any warranty or implied warranty 11 * of merchantability or fitness for a particular purpose. 12 * 13 * See the GNU General Public License version 2 for more details. 14 */ 15 16 #include <linux/if_arp.h> 17 #include <linux/netdevice.h> 18 #include <linux/skbuff.h> 19 #include <linux/export.h> 20 #include <net/llc.h> 21 #include <net/llc_pdu.h> 22 23 /** 24 * llc_mac_hdr_init - fills MAC header fields 25 * @skb: Address of the frame to initialize its MAC header 26 * @sa: The MAC source address 27 * @da: The MAC destination address 28 * 29 * Fills MAC header fields, depending on MAC type. Returns 0, If MAC type 30 * is a valid type and initialization completes correctly 1, otherwise. 31 */ 32 int llc_mac_hdr_init(struct sk_buff *skb, 33 const unsigned char *sa, const unsigned char *da) 34 { 35 int rc = -EINVAL; 36 37 switch (skb->dev->type) { 38 case ARPHRD_ETHER: 39 case ARPHRD_LOOPBACK: 40 rc = dev_hard_header(skb, skb->dev, ETH_P_802_2, da, sa, 41 skb->len); 42 if (rc > 0) 43 rc = 0; 44 break; 45 default: 46 break; 47 } 48 return rc; 49 } 50 51 /** 52 * llc_build_and_send_ui_pkt - unitdata request interface for upper layers 53 * @sap: sap to use 54 * @skb: packet to send 55 * @dmac: destination mac address 56 * @dsap: destination sap 57 * 58 * Upper layers calls this function when upper layer wants to send data 59 * using connection-less mode communication (UI pdu). 60 * 61 * Accept data frame from network layer to be sent using connection- 62 * less mode communication; timeout/retries handled by network layer; 63 * package primitive as an event and send to SAP event handler 64 */ 65 int llc_build_and_send_ui_pkt(struct llc_sap *sap, struct sk_buff *skb, 66 unsigned char *dmac, unsigned char dsap) 67 { 68 int rc; 69 llc_pdu_header_init(skb, LLC_PDU_TYPE_U, sap->laddr.lsap, 70 dsap, LLC_PDU_CMD); 71 llc_pdu_init_as_ui_cmd(skb); 72 rc = llc_mac_hdr_init(skb, skb->dev->dev_addr, dmac); 73 if (likely(!rc)) 74 rc = dev_queue_xmit(skb); 75 else 76 kfree_skb(skb); 77 return rc; 78 } 79 80 EXPORT_SYMBOL(llc_mac_hdr_init); 81 EXPORT_SYMBOL(llc_build_and_send_ui_pkt); 82