llc_output.c 2.4 KB

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  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. #include <linux/if_arp.h>
  16. #include <linux/if_tr.h>
  17. #include <linux/netdevice.h>
  18. #include <linux/trdevice.h>
  19. #include <linux/skbuff.h>
  20. #include <linux/export.h>
  21. #include <net/llc.h>
  22. #include <net/llc_pdu.h>
  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. switch (skb->dev->type) {
  37. case ARPHRD_IEEE802_TR:
  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. WARN(1, "device type not supported: %d\n", skb->dev->type);
  47. }
  48. return rc;
  49. }
  50. /**
  51. * llc_build_and_send_ui_pkt - unitdata request interface for upper layers
  52. * @sap: sap to use
  53. * @skb: packet to send
  54. * @dmac: destination mac address
  55. * @dsap: destination sap
  56. *
  57. * Upper layers calls this function when upper layer wants to send data
  58. * using connection-less mode communication (UI pdu).
  59. *
  60. * Accept data frame from network layer to be sent using connection-
  61. * less mode communication; timeout/retries handled by network layer;
  62. * package primitive as an event and send to SAP event handler
  63. */
  64. int llc_build_and_send_ui_pkt(struct llc_sap *sap, struct sk_buff *skb,
  65. unsigned char *dmac, unsigned char dsap)
  66. {
  67. int rc;
  68. llc_pdu_header_init(skb, LLC_PDU_TYPE_U, sap->laddr.lsap,
  69. dsap, LLC_PDU_CMD);
  70. llc_pdu_init_as_ui_cmd(skb);
  71. rc = llc_mac_hdr_init(skb, skb->dev->dev_addr, dmac);
  72. if (likely(!rc))
  73. rc = dev_queue_xmit(skb);
  74. else
  75. kfree_skb(skb);
  76. return rc;
  77. }
  78. EXPORT_SYMBOL(llc_mac_hdr_init);
  79. EXPORT_SYMBOL(llc_build_and_send_ui_pkt);