c++ - Why raw socket sendto() function fails with 10022? -

i developing protocol fuzzer icmp, tcp, udp , on under vs2010. have sent out icmp , udp packets raw socket interface. encountered problem when sending tcp.

my environment: windows 7 ultimate x64, administrator account.

here way:

1) construct transport header , data myself.

2) use raw socket ipv4 header , below. rawconnect() function used create such raw socket. strip ip address, , strprotocol ip protocol number need specified (like icmp 1, igmp 2, tcp 6, udp 17). because didn't construct ip header myself (m_bselfconstructipheader = false), ip protocol number necessary. didn't know if used right or not?

3) use sendto() function send buffer, returns -1, , wsagetlasterror() returns 10022 means "an invalid argument supplied."

below code, thx!

#include "stdafx.h"  #include "afrawsocket.h"  #define ip_hdrincl 2  afrawsocket::afrawsocket() {     m_socket = null;     m_bselfconstructipheader = false; }  cstring afrawsocket::itos(int i) {     cstring strtemp;     strtemp.format(_t("%d"), i);     return strtemp; }  int afrawsocket::stoi(cstring s) {     return _wtoi(s); }  // // cstringaתcstringw // cstringw afrawsocket::cstra2cstrw(const cstringa &cstrsrca) {     int len = multibytetowidechar(cp_acp, 0, lpcstr(cstrsrca), -1, null, 0);     wchar_t *wstr = new wchar_t[len];     memset(wstr, 0, len*sizeof(wchar_t));     multibytetowidechar(cp_acp, 0, lpcstr(cstrsrca), -1, wstr, len);     cstringw cstrdestw = wstr;     delete[] wstr;      return cstrdestw; }  // // cstringwתcstringa // cstringa afrawsocket::cstrw2cstra(const cstringw &cstrsrcw) {     int len = widechartomultibyte(cp_acp, 0, lpcwstr(cstrsrcw), -1, null, 0, null, null);     char *str = new char[len];     memset(str, 0, len);     widechartomultibyte(cp_acp, 0, lpcwstr(cstrsrcw), -1, str, len, null, null);     cstringa cstrdesta = str;     delete[] str;      return cstrdesta; }  void afrawsocket::setselfconstructipheader(bool bselfconstructipheader) {     m_bselfconstructipheader = bselfconstructipheader; }  bool afrawsocket::rawconnect(cstring strip, cstring strprotocol) {     int optval;     cstringa straip = cstrw2cstra(strip);      int iprotocol;     if (strprotocol == _t("n/a"))     {         iprotocol = 0;     }     else     {         iprotocol = stoi(strprotocol);     }      sockaddr_in mysock;     zeromemory((char*)&mysock,sizeof(mysock));//初始化     mysock.sin_family=af_inet;     mysock.sin_addr.s_addr=inet_addr(straip);      //create raw tcp packet     //printf("\ncreating raw tcp socket...");     //eth_p_all     //af_packet  //  if (iprotocol == ipproto_tcp) //  { //      iprotocol = ipproto_udp; //  }      if((m_socket = socket(af_inet, sock_raw, iprotocol/*ipproto_raw*/))==socket_error)     {         //printf("creation of raw socket failed.");         mymessagebox_error(_t("rawconnect"));         return false;     }     //printf("raw tcp socket created successfully.");     ////////////////////////////////////////////////      if (m_bselfconstructipheader)     {         //put socket in raw mode.         //printf("\nsetting socket in raw mode...");         if(setsockopt(m_socket, ipproto_ip, ip_hdrincl, (char *)&optval, sizeof(optval))==socket_error)         {             //printf("failed set socket in raw mode.");             mymessagebox_error(_t("rawconnect"));             return false;         }         //printf("successful.");         ////////////////////////////////////////////////     }   //  //target hostname //  printf("\nenter hostname : "); //  gets(host); //  printf("\nresolving hostname..."); //  if((server=gethostbyname(host))==0) //  { //      printf("unable resolve."); //      return 0; //  }     zeromemory(&m_dest, sizeof(m_dest));     m_dest.sin_family = af_inet;     //m_dest.sin_port   = htons(0);  //your destination port     m_dest.sin_addr.s_addr=inet_addr(straip);     //m_dest.sin_addr.s_addr=inet_addr("8.8.8.8");     //m_dest.sin_addr.s_addr=inet_addr("202.112.128.50");     //memcpy(&m_dest.sin_addr.s_addr,&mysock.sin_addr.s_addr,4);     //printf("resolved.");     /////////////////////////////////////////////////  //  if (bind(m_socket, (sockaddr *) &m_dest, sizeof(m_dest)) < 0) //  { //      int ierror = wsagetlasterror(); //      mymessagebox_error(_t("rawconnect")); //      return false; //  }      return true; }  void afrawsocket::rawsend(lpbyte lpbuffer, dword dwsize) {     int iret = sendto(m_socket , (const char *) lpbuffer, dwsize, 0, (sockaddr *)&m_dest, sizeof(m_dest));     //if (iret == socket_error)     if (iret <= 0)     {         //printf("error sending packet : %d",wsagetlasterror());         int ierror  =wsagetlasterror();         mymessagebox_error(_t("rawsend"));     } }  void afrawsocket::rawdisconnect() {     if (m_socket)     {         closesocket(m_socket);         m_socket = null;     } }