irlmp2.c

这个是从国外弄到的一个红外协议栈

/*
  Copyright (C) 2002-2003 Gerd Rausch, BlauLogic (http://blaulogic.com)
  All rights reserved.

  Redistribution and use in source and binary forms, with or without
  modification, are permitted provided that the following conditions
  are met:

  1. Redistributions of source code must retain the above copyright
     notice, this list of conditions and the following disclaimer.

  2. Redistributions in binary form must reproduce the above copyright
     notice, this list of conditions and the following disclaimer in the
     documentation and/or other materials provided with the distribution.

  3. Except as contained in this notice, neither the name of BlauLogic
     nor the name(s) of the author(s) may be used to endorse or promote
     products derived from this software without specific prior written
     permission.

  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
  IN NO EVENT SHALL THE AUTHOR(S) OR BLAULOGIC BE LIABLE FOR ANY CLAIM,
  DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR
  THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/

#include <string.h>

#include "irlmp.h"

static uint16_t iap_name_equal(char *name, uint8_t *encoded, uint16_t size)
{
  uint16_t i, j;

  if(size<1)
    return 0;

  i=0;
  while(i<encoded[0] && name[i]) {
    j=i+1;
    if(j>=size || name[i]!=encoded[j])
      break;
    i=j;
  }

  if(i<encoded[0] || name[i])
    return 0;

  return i+1;
}

static void iap_reply_getvaluebyclass(IrLAP_Context *context_p, IrLMP_Frame *req_p,
				      uint8_t status, uint16_t obj_id, uint16_t *value_p)
{
  IrLAP_Small_Frame frame;
  IrLMP_Frame *resp_p=(IrLMP_Frame *)&frame;
  uint16_t n;

  resp_p->head.dlsap_sel=req_p->head.slsap_sel & ~IRLMP_DLSAP_C_MASK;
  resp_p->head.slsap_sel=req_p->head.dlsap_sel & ~IRLMP_DLSAP_C_MASK;
  resp_p->u.ctl.opcode=req_p->u.ctl.opcode | IRIAP_CTL_LST_MASK;

  n=0;

  /* status */
  resp_p->u.ctl.info[n++]=status;

  if(value_p) {
    /* len */
    resp_p->u.ctl.info[n++]=0;
    resp_p->u.ctl.info[n++]=1;

    /* obj_id */
    resp_p->u.ctl.info[n++]=obj_id>>8;
    resp_p->u.ctl.info[n++]=obj_id;
  
    /* value */
    resp_p->u.ctl.info[n++]=IRIAP_VALUE_TYPE_INTEGER;

    resp_p->u.ctl.info[n++]=0;
    resp_p->u.ctl.info[n++]=0;
    resp_p->u.ctl.info[n++]=*value_p>>8;
    resp_p->u.ctl.info[n++]=*value_p;
  }
  
  irlap2_send_i_frame(context_p, (IrLAP_Frame *)&frame, sizeof(IrLMP_Head)+sizeof(IrLMP_Ctl)+n);
}

static void iap_handle_getvaluebyclass(IrLAP_Context *context_p, IrLMP_Frame *req_p, uint16_t size, IrIAS_Node **ias_nodes_p)
{
  IrIAS_Node **node_p;
  uint16_t n, i;

  for(node_p=ias_nodes_p; *node_p; node_p++) {
    n=size-sizeof(IrLMP_Head)-sizeof(IrLMP_Ctl);
    i=0;

    if((i=iap_name_equal((*node_p)->class_name, req_p->u.ctl.info, n)) &&
       (i=iap_name_equal((*node_p)->attr_name, req_p->u.ctl.info+i, n-i))) {
      iap_reply_getvaluebyclass(context_p, req_p, IRIAP_RESP_GVBCL_SUCCESS, (*node_p)->obj_id, &(*node_p)->value);
      return;
    }
  }

  iap_reply_getvaluebyclass(context_p, req_p, IRIAP_RESP_GVBCL_NOSUCHATTR, 0, 0);
}

static void reply(IrLAP_Context *context_p, IrLMP_Frame *req_p, uint8_t unsupported)
{
  IrLAP_Small_Frame frame;
  IrLMP_Frame *resp_p=(IrLMP_Frame *)&frame;

  if(unsupported)
    resp_p->u.ctl.info[0]=IRLMP_RESP_UNSUPPORTED;

  irlmp2_reply(context_p, req_p, resp_p, sizeof(IrLMP_Head)+sizeof(IrLMP_Ctl)+(unsupported ? 1 : 0));
}

void irlmp2_reply(IrLAP_Context *context_p, IrLMP_Frame *req_p, IrLMP_Frame *resp_p, uint16_t size)
{
  if(req_p->head.dlsap_sel & IRLMP_DLSAP_C_MASK) {
    resp_p->head.dlsap_sel=req_p->head.slsap_sel | IRLMP_DLSAP_C_MASK;
    resp_p->head.slsap_sel=req_p->head.dlsap_sel & ~IRLMP_DLSAP_C_MASK;
    resp_p->u.ctl.opcode=req_p->u.ctl.opcode | IRLMP_OP_A_MASK;
  } else {
    resp_p->head.dlsap_sel=req_p->head.slsap_sel & ~IRLMP_DLSAP_C_MASK;
    resp_p->head.slsap_sel=req_p->head.dlsap_sel & ~IRLMP_DLSAP_C_MASK;
    if(!(req_p->head.dlsap_sel & ~IRLMP_DLSAP_C_MASK))
      resp_p->u.ctl.opcode=req_p->u.ctl.opcode | IRIAP_CTL_LST_MASK;
  }

  irlap2_send_i_frame(context_p, (IrLAP_Frame *)resp_p, size);
}

void irlmp2_handle_ctl_frame(IrLAP_Context *context_p, IrLMP_Frame *req_p)
{
  switch(req_p->u.ctl.opcode) {
  case IRLMP_OP_CONNECT:
    reply(context_p, req_p, 0);
    break;
  case IRLMP_OP_DISCONNECT:
    reply(context_p, req_p, 0);
    break;
  case IRLMP_OP_ACCESS_MODE:
    reply(context_p, req_p, 1);
    break;
  }
}

int16_t irlmp2_receive_frame(IrLAP_Context *context_p, IrLAP_Frame *frame_p,
			     IrLAP_Frame *last_resp_p, uint16_t last_resp_size,
			     uint8_t service_hint1,
			     IrIAS_Node **ias_nodes_p)
{
  IrLMP_Frame *req_p;
  int16_t n;

  req_p=(IrLMP_Frame *)frame_p;

  if((n=irlap2_receive_i_frame(context_p, frame_p,
			       last_resp_p, last_resp_size,
			       irlmp_get_dev_info, service_hint1))<0)
    return -1;

  do {
    if(n<sizeof(IrLMP_Head)+
       ((req_p->head.dlsap_sel & IRLMP_DLSAP_C_MASK) ? sizeof(IrLMP_Ctl) : 0))
      continue;

    if(req_p->head.dlsap_sel & ~IRLMP_DLSAP_C_MASK)
      return n;

    if(req_p->head.dlsap_sel & IRLMP_DLSAP_C_MASK) {
      /* link control frame */
      irlmp2_handle_ctl_frame(context_p, req_p);
    } else {
      /* data frame */
      switch(req_p->u.ctl.opcode & ~IRIAP_CTL_LST_MASK) {
      case IRLMP_OP_LM_GETVALUEBYCLASS:
	iap_handle_getvaluebyclass(context_p, req_p, n, ias_nodes_p);
	break;
      default:
	reply(context_p, req_p, 1);
	break;
      }
    }
  } while((n=irlap2_receive_i_frame(context_p, frame_p,
				    0, 0,
				    irlmp_get_dev_info, service_hint1))>=0);

  return -1;
}