snmptrap.c

windows的snmp api源码

// snmptrap.c
//
// Original Microsoft code modified by ACE*COMM
// for use with WSNMP32.DLL and other trap receiving
// clients, per contract.
//
// Bob Natale, ACE*COMM ([e-mail])
// For NT v5 Beta, v970228
// Additional enhancements planned.
//
// This version of SNMPTRAP has no dependencies
// on either MGMTAPI.DLL or WSNMP32.DLL.
//
// WinSNMP clients use the SnmpRegister() function.
//
// Other clients will need to match the following
// values and structures:
//
//    SNMP_TRAP structure
//    SNMPTRAPPIPE name
//    TRAPBUFSIZE value
//
// Change log:
// ------------------------------------------------
// 4.0.1381.3  Apr 8, 1998 Bob Natale
//
// 1.  Re-worked the trap port monitoring thread into
//     two threads...one for IP and one for IPX, to
//     comply with WinSock v2's restrictions against
//     multi-protocol select().
//
// 2.  General clean-up/streamlining wrt "legacy" code
//     from original MS version...more to do here, esp.
//     wrt error handling code that does not do anything.
// ------------------------------------------------
// 4.0.1381.4  Apr. 10, 1998 Bob Natale
//
// 1.  Replaced mutex calls with critical_sectin calls.
//
// 2.  Cleaned out some dead code (removed commented out code)
// ------------------------------------------------
#include <windows.h>
#include <winsock.h>
#include <wsipx.h>
#include <process.h>
//--------------------------- PRIVATE VARIABLES -----------------------------
#define SNMPMGRTRAPPIPE "\\\\.\\PIPE\\MGMTAPI"
#define MAX_OUT_BUFS    16
#define TRAPBUFSIZE     4096
#define IP_TRAP_PORT    162
#define IPX_TRAP_PORT   36880
// ******** INITIALIZE A LIST HEAD ********
#define ll_init(head) (head)->next = (head)->prev = (head);
// ******** TEST A LIST FOR EMPTY ********
#define ll_empt(head) ( ((head)->next) == (head) )
// ******** Get ptr to next entry ********
#define ll_next(item,head)\
( (ll_node *)(item)->next == (head) ? 0 : \
(ll_node *)(item)->next )
// ******** ADD AN ITEM TO THE END OF A LIST ********
#define ll_adde(item,head)\
   {\
   ll_node *pred = (head)->prev;\
   ((ll_node *)(item))->next = (head);\
   ((ll_node *)(item))->prev = pred;\
   (pred)->next = ((ll_node *)(item));\
   (head)->prev = ((ll_node *)(item));\
   }
// ******** REMOVE AN ITEM FROM A LIST ********
#define ll_rmv(item)\
   {\
   ll_node *pred = ((ll_node *)(item))->prev;\
   ll_node *succ = ((ll_node *)(item))->next;\
   pred->next = succ;\
   succ->prev = pred;\
   }
// ******** List head/node ********
typedef struct ll_s
   { // linked list structure
   struct  ll_s *next;  // next node
   struct  ll_s *prev;  // prev. node
   } ll_node;           // linked list node
typedef struct
   {// shared by server trap thread and pipe thread
   ll_node  links;
   HANDLE   hPipe;
   } svrPipeListEntry;
typedef struct
   {
   SOCKADDR Addr;              
   int      AddrLen;           
   UINT     TrapBufSz;
   char     TrapBuf[TRAPBUFSIZE];   // the size of this array should match the size of the structure
                                    // defined in wsnmp_no.c!!!
   }        SNMP_TRAP, *PSNMP_TRAP;

HANDLE hExitEvent = NULL;
LPCTSTR svcName = "SNMPTRAP";
SERVICE_STATUS_HANDLE hService = 0;
SERVICE_STATUS status =
  {SERVICE_WIN32, SERVICE_STOPPED, SERVICE_ACCEPT_STOP, NO_ERROR, 0, 0, 0};
SOCKET ipSock = INVALID_SOCKET;
SOCKET ipxSock = INVALID_SOCKET;
HANDLE ipThread = NULL;
HANDLE ipxThread = NULL;
CRITICAL_SECTION cs_PIPELIST;
ll_node *pSvrPipeListHead = NULL;

//--------------------------- PRIVATE PROTOTYPES ----------------------------
DWORD WINAPI svrTrapThread (IN OUT LPVOID threadParam);
DWORD WINAPI svrPipeThread (IN LPVOID threadParam);
VOID WINAPI svcHandlerFunction (IN DWORD dwControl);
VOID WINAPI svcMainFunction (IN DWORD dwNumServicesArgs,
                             IN LPSTR *lpServiceArgVectors);

//--------------------------- PRIVATE PROCEDURES ----------------------------
VOID WINAPI svcHandlerFunction (IN DWORD dwControl)
{
if (dwControl == SERVICE_CONTROL_STOP)
   {
   status.dwCurrentState = SERVICE_STOP_PENDING;
   status.dwCheckPoint++;
   status.dwWaitHint = 45000;
   if (!SetServiceStatus(hService, &status))
      exit(1);
   // set event causing trap thread to terminate
   if (!SetEvent(hExitEvent))
      {
      status.dwCurrentState = SERVICE_STOPPED;
      status.dwWin32ExitCode = ERROR_SERVICE_SPECIFIC_ERROR;
      status.dwServiceSpecificExitCode = 1; // OPENISSUE - svc err code
      status.dwCheckPoint = 0;
      status.dwWaitHint = 0;
      // We are exiting in any case, so ignore any error...
      SetServiceStatus (hService, &status);
      exit(1);
      }
   }
else
   //   dwControl == SERVICE_CONTROL_INTERROGATE
   //   dwControl == SERVICE_CONTROL_PAUSE
   //   dwControl == SERVICE_CONTROL_CONTINUE
   //   dwControl == <anything else>
   {
   if (status.dwCurrentState == SERVICE_STOP_PENDING ||
       status.dwCurrentState == SERVICE_START_PENDING)
      status.dwCheckPoint++;
   if (!SetServiceStatus (hService, &status))
      exit(1);
   }
} // end_svcHandlerFunction()

VOID WINAPI svcMainFunction (IN DWORD dwNumServicesArgs,
                             IN LPSTR *lpServiceArgVectors)
{
WSADATA WinSockData;
HANDLE hPipeThread = NULL;
DWORD  dwThreadId;
//---------------------------------------------------------------------
hService = RegisterServiceCtrlHandler (svcName, svcHandlerFunction);
if (hService == 0)
   {
   status.dwCurrentState = SERVICE_STOPPED;
   status.dwWin32ExitCode = ERROR_SERVICE_SPECIFIC_ERROR;
   status.dwServiceSpecificExitCode = 2; // OPENISSUE - svc err code
   status.dwCheckPoint = 0;
   status.dwWaitHint = 0;
   // We are exiting in any case, so ignore any error...
   SetServiceStatus (hService, &status);
   exit(1);
   }
status.dwCurrentState = SERVICE_START_PENDING;
status.dwWaitHint = 20000;

if (!SetServiceStatus(hService, &status))
   exit(1);

__try
{
    InitializeCriticalSection (&cs_PIPELIST);
}
__except(EXCEPTION_EXECUTE_HANDLER)
{
   exit(1);
}

if (WSAStartup ((WORD)0x0101, &WinSockData))
   goto CLOSE_OUT; // WinSock startup failure


// allocate linked-list header for client received traps
if ((pSvrPipeListHead = (ll_node *)GlobalAlloc (GHND, sizeof(ll_node))) == NULL)
   goto CLOSE_OUT;
ll_init(pSvrPipeListHead);
if ((hPipeThread = (HANDLE)_beginthreadex
                   (NULL, 0, svrPipeThread, NULL, 0, &dwThreadId)) == 0)
   goto CLOSE_OUT;
//-----------------------------------------------------------------------------------
//CHECK_IP:
ipSock = socket (AF_INET, SOCK_DGRAM, 0);
if (ipSock != INVALID_SOCKET)
   {
   struct sockaddr_in localAddress_in;
   struct servent *serv;
   ZeroMemory (&localAddress_in, sizeof(localAddress_in));
   localAddress_in.sin_family = AF_INET;
   if ((serv = getservbyname ("snmp-trap", "udp")) == NULL)
      localAddress_in.sin_port = htons (IP_TRAP_PORT);
   else
      localAddress_in.sin_port = (SHORT)serv->s_port;
   localAddress_in.sin_addr.s_addr = htonl (INADDR_ANY);
   if (bind (ipSock, (LPSOCKADDR)&localAddress_in, sizeof(localAddress_in)) != SOCKET_ERROR)
      ipThread = (HANDLE)_beginthreadex
                 (NULL, 0, svrTrapThread, (LPVOID)ipSock, 0, &dwThreadId);
   }
//-----------------------------------------------------------------------------------
//CHECK_IPX:
ipxSock = socket (AF_IPX, SOCK_DGRAM, NSPROTO_IPX);
if (ipxSock != INVALID_SOCKET)
   {
   struct sockaddr_ipx localAddress_ipx;
   ZeroMemory (&localAddress_ipx, sizeof(localAddress_ipx));
   localAddress_ipx.sa_family = AF_IPX;
   localAddress_ipx.sa_socket = htons (IPX_TRAP_PORT);
   if (bind (ipxSock, (LPSOCKADDR)&localAddress_ipx, sizeof(localAddress_ipx)) != SOCKET_ERROR)
      ipxThread = (HANDLE)_beginthreadex
                  (NULL, 0, svrTrapThread, (LPVOID)ipxSock, 0, &dwThreadId);
   }
//-----------------------------------------------------------------------------------
// We are ready to listen for traps...
status.dwCurrentState = SERVICE_RUNNING;
status.dwCheckPoint   = 0;
status.dwWaitHint     = 0;
if (!SetServiceStatus(hService, &status))
   goto CLOSE_OUT;
WaitForSingleObject (hExitEvent, INFINITE);
//-----------------------------------------------------------------------------------
CLOSE_OUT:
EnterCriticalSection (&cs_PIPELIST);
if (hPipeThread != NULL)
   {
   TerminateThread (hPipeThread, 0);
   CloseHandle (hPipeThread);
   }
if (ipSock != INVALID_SOCKET)
   closesocket (ipSock);
if (ipThread != NULL)
   {
   WaitForSingleObject (ipThread, INFINITE);
   CloseHandle (ipThread);
   }
if (ipxSock != INVALID_SOCKET)
   closesocket (ipxSock);
if (ipxThread != NULL)
   {
   WaitForSingleObject (ipxThread, INFINITE);
   CloseHandle (ipxThread);
   }
if (pSvrPipeListHead != NULL)
   GlobalFree (pSvrPipeListHead);
LeaveCriticalSection (&cs_PIPELIST);
DeleteCriticalSection (&cs_PIPELIST);
WSACleanup();
status.dwCurrentState = SERVICE_STOPPED;