gpeername.c

来自「用于嵌入式系统的TCP/IP协议栈」· C语言 代码 · 共 106 行

/***********************************************************************/
/*                                                                     */
/*   Module:  gpeername.c                                              */
/*   Release: 2001.3                                                   */
/*   Version: 99.0                                                     */
/*   Purpose: getpeername() implementation                             */
/*                                                                     */
/*---------------------------------------------------------------------*/
/*                                                                     */
/*               Copyright 1999, Blunk Microsystems                    */
/*                      ALL RIGHTS RESERVED                            */
/*                                                                     */
/*   Licensees have the non-exclusive right to use, modify, or extract */
/*   this computer program for software development at a single site.  */
/*   This program may be resold or disseminated in executable format   */
/*   only. The source code may not be redistributed or resold.         */
/*                                                                     */
/***********************************************************************/
#include "../tcp_ipp.h"
#include <string.h>

/***********************************************************************/
/* Global Function Definitions                                         */
/***********************************************************************/

/***********************************************************************/
/* getpeername: Get port and IP address of connected peer              */
/*                                                                     */
/*      Inputs: s = socket identifier                                  */
/*              addrlen = sizeof(struct sockaddr_in)                   */
/*                                                                     */
/*      Output: *a = remote port and IP address                        */
/*     Returns: 0 if no errors, else -1 with errno set to error code   */
/*                                                                     */
/***********************************************************************/
int getpeername(int s, void *a, int *addrlen)
{
  SOCKET sock = &Socks[s - 1];
  SockAddr addr;
  int rc = 0;

#if OS_PARM_CHECK
  /*-------------------------------------------------------------------*/
  /* Verify protocol has been initialized.                             */
  /*-------------------------------------------------------------------*/
  if (!Net.Initialized)
  {
    NetError(NULL, ENETDOWN);
    return -1;
  }

  /*-------------------------------------------------------------------*/
  /* Check for valid socket ID.                                        */
  /*-------------------------------------------------------------------*/
  if (InvalidHandle(s))
  {
    NetError(NULL, ENOTSOCK);
    return -1;
  }

  /*-------------------------------------------------------------------*/
  /* Verify sockaddr pointer and addrlen parameters.                   */
  /*-------------------------------------------------------------------*/
  if ((a == NULL) || (*addrlen != sizeof(struct sockaddr_in)))
  {
    NetError(sock, EFAULT);
    return -1;
  }
#endif

  /*-------------------------------------------------------------------*/
  /* Gain exclusive socket API access and stack internals access.      */
  /*-------------------------------------------------------------------*/
  if (semPend(sock->api_access, WAIT_FOREVER))
  {
    NetError(NULL, ENOTSOCK);
    return -1;
  }
  semPend(Net.IntSem, WAIT_FOREVER);

  /*-------------------------------------------------------------------*/
  /* Verify socket is connected and output remote address and port.    */
  /*-------------------------------------------------------------------*/
  if ((sock->flags & SF_CONNECTED) == FALSE)
  {
    NetError(sock, ENOTCONN);
    rc = -1;
  }
  else
  {
    memset(&addr, 0, sizeof(struct sockaddr_in));
    addr.sin_family = AF_INET;
    addr.sin_port = sock->remote.sin_port;
    addr.sin_addr = sock->remote.sin_addr;
    *(SockAddr *)a = addr;
  }

  /*-------------------------------------------------------------------*/
  /* Release exclusive API and internals access and return result.     */
  /*-------------------------------------------------------------------*/
  semPost(sock->api_access);
  semPost(Net.IntSem);
  return rc;
}