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 return rc;
76 }
77
78 EXPORT_SYMBOL(llc_mac_hdr_init);
79 EXPORT_SYMBOL(llc_build_and_send_ui_pkt);
80
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