linux/net/llc/llc_output.c

75 lines
2.0 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* llc_output.c - LLC minimal output path
*
* Copyright (c) 1997 by Procom Technology, Inc.
* 2001-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
*/
#include <linux/if_arp.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/export.h>
#include <net/llc.h>
#include <net/llc_pdu.h>
/**
* llc_mac_hdr_init - fills MAC header fields
* @skb: Address of the frame to initialize its MAC header
* @sa: The MAC source address
* @da: The MAC destination address
*
* Fills MAC header fields, depending on MAC type. Returns 0, If MAC type
* is a valid type and initialization completes correctly 1, otherwise.
*/
int llc_mac_hdr_init(struct sk_buff *skb,
const unsigned char *sa, const unsigned char *da)
{
int rc = -EINVAL;
switch (skb->dev->type) {
case ARPHRD_ETHER:
case ARPHRD_LOOPBACK:
rc = dev_hard_header(skb, skb->dev, ETH_P_802_2, da, sa,
skb->len);
if (rc > 0)
rc = 0;
break;
default:
break;
}
return rc;
}
/**
* llc_build_and_send_ui_pkt - unitdata request interface for upper layers
* @sap: sap to use
* @skb: packet to send
* @dmac: destination mac address
* @dsap: destination sap
*
* Upper layers calls this function when upper layer wants to send data
* using connection-less mode communication (UI pdu).
*
* Accept data frame from network layer to be sent using connection-
* less mode communication; timeout/retries handled by network layer;
* package primitive as an event and send to SAP event handler
*/
int llc_build_and_send_ui_pkt(struct llc_sap *sap, struct sk_buff *skb,
unsigned char *dmac, unsigned char dsap)
{
int rc;
llc_pdu_header_init(skb, LLC_PDU_TYPE_U, sap->laddr.lsap,
dsap, LLC_PDU_CMD);
llc_pdu_init_as_ui_cmd(skb);
rc = llc_mac_hdr_init(skb, skb->dev->dev_addr, dmac);
if (likely(!rc))
rc = dev_queue_xmit(skb);
else
kfree_skb(skb);
return rc;
}
EXPORT_SYMBOL(llc_mac_hdr_init);
EXPORT_SYMBOL(llc_build_and_send_ui_pkt);