| rjw | 1f88458 | 2022-01-06 17:20:42 +0800 | [diff] [blame] | 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); |