/*---------------------------------------
SNMP資訊刺探程式

----------------------------------------*/

#include <stdio.h>
#include <malloc.h>
#include <snmp.h>
#include <mgmtapi.h>
#pragma comment(lib,"Mgmtapi.lib")
#pragma comment(lib,"Snmpapi.lib")
//利用 SNMP API時需要以上標頭檔案和庫檔案
#define GET     1  //get，就理解成獲取一個資訊。
#define GETNEXT 2  //getnext，就理解成獲取下一個資訊。
#define WALK    3  //walk，就理解成獲取一堆資訊,即所有資料庫子樹/子目錄的資訊

#define TIMEOUT 6000 /* milliseconds */
#define RETRIES 3

//一些有用的oid
char *SnmpOid[5]={".1.3.6.1.2.1.25.4.2.1.2",//程序列表
                ".1.3.6.1.4.1.77.1.2.25.1.1",//系統使用者
    ".1.3.6.1.4.1.77.1.4.1.0",//域名
    ".1.3.6.1.2.1.25.6.3.1.2",//列出安裝的軟體
    ".1.3.6.1.2.1.1"};// 列出系統資訊
void usage(char *name)
{
printf("=================SNMP tool================/n");
printf("

}

int main(int  argc,char *argv[])
    {
    int                operation;
    LPSTR              agent;
    LPSTR              community;
 
    RFC1157VarBindList variableBindings;
    LPSNMP_MGR_SESSION session;

    int        timeout = TIMEOUT;
    int        retries = RETRIES;
    int i;
    BYTE       requestType;
    AsnInteger errorStatus;
    AsnInteger errorIndex;
    char        *chkPtr = NULL;
    operation = WALK;  //這個程式使用WALK來獲取資訊

    if  (argc != 3)
        {
        usage(argv[0]);
        return 0;
        }
   else
          {
  AsnObjectIdentifier reqObject;
        // 取得IP地址
  agent = (LPSTR)SNMP_malloc(strlen(*argv) + 1);
  strcpy(agent, argv[1]);
  
        community="public";//設定查詢密碼
   
        variableBindings.list = NULL;
        variableBindings.len = 0;

  // 設定 oid
  if(!strcmp(argv[2],"sysprocess"))i=0;
  else if(!strcmp(argv[2],"sysuser"))i=1;
  else if(!strcmp(argv[2],"domainname"))i=2;
  else if(!strcmp(argv[2],"software"))i=3;
  else if(!strcmp(argv[2],"sysinf"))i=4;
  else{
   usage(argv[0]);
   return 0;
  }
printf("%s/n",SnmpOid[i]);

           
            // 把字串轉換成標準oid
     if (!SnmpMgrStrToOid(SnmpOid[i], &reqObject))
        {
         printf("Error: Invalid oid, %s, specified./n", *argv);
         return 1;
        }
     else
       {
       variableBindings.len++;
   if ((variableBindings.list = (RFC1157VarBind *)SNMP_realloc(
                   variableBindings.list, sizeof(RFC1157VarBind) *
                   variableBindings.len)) == NULL)
      {
         printf("Error: Error allocating oid, %s./n",*argv);
         return 1;
      }
 variableBindings.list[variableBindings.len - 1].name=reqObject;
 variableBindings.list[variableBindings.len - 1].value.asnType=ASN_NULL;
     }
   // Make sure only one variable binding was specified if operation
   // is WALK.
        if (operation == WALK && variableBindings.len != 1)
            {
            printf("Error: Multiple oids specified for WALK./n");
            return 1;
            }

        // Establish a SNMP session to communicate with the remote agent.  The
        // community, communications timeout, and communications retry count
        // for the session are also required.

if ((session = SnmpMgrOpen(agent, community, timeout, retries)) == NULL)
     {
      printf("error on SnmpMgrOpen %d/n", GetLastError());
      return 1;
      }
   } // end if
 {
  
        AsnObjectIdentifier root;
        AsnObjectIdentifier tempOid;
        SnmpUtilOidCpy(&root, &variableBindings.list[0].name);
        requestType = ASN_RFC1157_GETNEXTREQUEST;

        for(;;)
            {
            if (!SnmpMgrRequest(session, requestType, &variableBindings,
                                &errorStatus, &errorIndex))
                {
                printf("error on SnmpMgrRequest %d/n", GetLastError());
                break;
                }
            else
                {
               
   if (errorStatus == SNMP_ERRORSTATUS_NOSUCHNAME ||
          SnmpUtilOidNCmp(&variableBindings.list[0].name,
                                 &root, root.idLength))
              {
              printf("End of MIB subtree./n/n");
           break;
       }

    if (errorStatus > 0)
   {
   printf("Error: errorStatus=%d, errorIndex=%d /n", errorStatus, errorIndex);
   break;
   }
   else
      {
      // 列印查詢的結果
      char *string = NULL;
     SnmpMgrOidToStr(&variableBindings.list[0].name, &string);
     printf("Variable = %s/n", string);
     if (string) SNMP_free(string);
      printf("Value    = ");
      SnmpUtilPrintAsnAny(&variableBindings.list[0].value);
      printf("/n");
     }
} // end if()
// 準備下一次查詢
  SnmpUtilOidCpy(&tempOid, &variableBindings.list[0].name);
  SnmpUtilVarBindFree(&variableBindings.list[0]);
  SnmpUtilOidCpy(&variableBindings.list[0].name, &tempOid);
  variableBindings.list[0].value.asnType = ASN_NULL;
  SnmpUtilOidFree(&tempOid);
} // end while()
   // 釋放資源

   SnmpUtilVarBindListFree(&variableBindings);
   SnmpUtilOidFree(&root);
}
  // 關閉 SNMP session
  if (!SnmpMgrClose(session))//清理退出
    {
     printf("error on SnmpMgrClose %d/n", GetLastError());
     return 1;
    }

 
  return 0;
 }