UserUtils.cpp

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#include "blocxx/BLOCXX_config.h"
#include "blocxx/Mutex.hpp"
#include "blocxx/MutexLock.hpp"
#include "blocxx/GlobalMutex.hpp"
#include "blocxx/UserUtils.hpp"

#ifdef BLOCXX_HAVE_UNISTD_H
#include <unistd.h>
#endif

#ifdef BLOCXX_HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif

#ifdef BLOCXX_HAVE_PWD_H
#include <pwd.h>
#endif

#include <cerrno>
#include <vector>

#ifdef BLOCXX_WIN32

BLOCXX_NAMESPACE::UserId geteuid(void )
{
   // SID/uid Win32/NIX wrapper 
   BLOCXX_NAMESPACE::UserId sid = (BLOCXX_NAMESPACE::UserId)NULL;
   HANDLE pToken = (HANDLE)0L;
   DWORD bufLength = 256;
   static int* tkUser[256]; // only a static buffer we need with no SID copy privileges :(

   if ( ::OpenProcessToken(::GetCurrentProcess(), TOKEN_QUERY, &pToken) )
   {
      ::GetTokenInformation(pToken, TokenUser, tkUser, bufLength, &bufLength);
      sid = ((TOKEN_USER*)tkUser)->User.Sid;
      TCHAR sName[MAX_PATH], sDName[MAX_PATH];
      DWORD sNameLen, sDNameLen = sNameLen = MAX_PATH;
      SID_NAME_USE eUse;
      ::LookupAccountSid( NULL, sid, sName, &sNameLen, sDName, &sDNameLen, &eUse);
      CloseHandle(pToken);
   }
   return sid;
}
#endif //BLOCXX_WIN32

namespace BLOCXX_NAMESPACE
{

namespace UserUtils
{

String getEffectiveUserId()
{
#ifdef BLOCXX_WIN32
   // TODO
   // The user ID is represented by a SID on Win32. Going to return 0 for
   // admin user on win32 for now. Eventually blocxx will
   // deal with userid on Win32 the proper way.

   // 20070625 Anton Afanasiev - maybe the better idea is to use ConvertSidToStringSid routing
   // the code below implements the same
   PSID_IDENTIFIER_AUTHORITY psia;
   DWORD dwSubAuthorities;
   DWORD dwSidRev=SID_REVISION;
   DWORD dwCounter;
   DWORD dwSidSize;
   UserId uid = ::geteuid();
   String strResult, strSubResult;

   if (!uid || !IsValidSid(uid))
      return String();
   psia = GetSidIdentifierAuthority(uid);
   dwSubAuthorities = *GetSidSubAuthorityCount(uid);
   dwSidSize = (15 + 12 + (12 * dwSubAuthorities) + 1) * sizeof(TCHAR);
   if ( (psia->Value[0] != 0) || (psia->Value[1] != 0) )
   {
      strSubResult.format(
         TEXT("0x%02hx%02hx%02hx%02hx%02hx%02hx"),
         (USHORT)psia->Value[0],
         (USHORT)psia->Value[1],
         (USHORT)psia->Value[2],
         (USHORT)psia->Value[3],
         (USHORT)psia->Value[4],
         (USHORT)psia->Value[5]);
   }
   else
   {
      strSubResult.format(
         TEXT("%lu"),
         (ULONG)(psia->Value[5]      )   +
         (ULONG)(psia->Value[4] <<  8)   +
         (ULONG)(psia->Value[3] << 16)   +
         (ULONG)(psia->Value[2] << 24) );
   }
   
   for (dwCounter=0 ; dwCounter < dwSubAuthorities ; dwCounter++)
   {
      strSubResult.format(
         TEXT("%s-%lu"), strSubResult.c_str(),
         *GetSidSubAuthority(uid, dwCounter) );
   }

   strResult.format(TEXT("S-%lu-%s"), dwSidRev, strSubResult);
   return strResult;
#else
   return String(Int64(::geteuid()));
#endif
}

String getCurrentUserName()
{
   bool ok;
#ifdef BLOCXX_WIN32
   return getUserName(geteuid(), ok);
#else
   return getUserName(getuid(),ok);
#endif
}

namespace
{
GlobalMutex g_getpwMutex = BLOCXX_GLOBAL_MUTEX_INIT();
}

namespace // anonymous
{
   // Get a sysconf value.  If no value is set (or another error occurs), return the default value.
   long getSysconfValue(int name, long default_value, int& error)
   {
#ifdef BLOCXX_WIN32
#pragma message(Reminder "TODO: Implement for Win if you use getSysconfValue not only for _SC_GETPW_R_SIZE_MAX")
      error = 0;
      return default_value; 
#else
      errno = 0;

      long l = sysconf(name);

      if( l == -1 )
      {
         if( errno == 0 )
         {
            // The POSIX standard says this means the limit is indefinite (not infinite).
            error = 0;
            return default_value;
         }
         else
         {
            error = errno;
            return default_value;
         }
      }
      else
      {
         error = 0;
         return l;
      }
#endif
   }

   long getSysconfValue(int name, long default_value)
   {
      int unused;
      return getSysconfValue(name, default_value, unused);
   }
} // end annymous namespace

String getUserName(uid_t uid,bool& ok)
{
#ifdef BLOCXX_WIN32
   // TODO
   // Ignore uid for right now. Just return the current User (WRONG!)
   // Need to come back to this later when the uid_t stuff is worked out.

   // 20070625 Anton Afanasiev
   TCHAR cchName[256], cchDomainName[256];
   SID_NAME_USE snuOutVar;
   DWORD cchNameBufLen = sizeof(cchName), cchDomainNameBufLen = sizeof(cchDomainName);

   ok = ::LookupAccountSid(NULL, 
            uid,
            cchName,
            &cchNameBufLen,
            cchDomainName,
            &cchDomainNameBufLen,
            &snuOutVar);
   return String(cchName);
#else

#ifdef BLOCXX_HAVE_GETPWUID_R
   passwd pw;
   size_t const additionalSize =
#ifdef _SC_GETPW_R_SIZE_MAX
      getSysconfValue(_SC_GETPW_R_SIZE_MAX, 10240);
#else
      10240;
#endif
   std::vector<char> additional(additionalSize);
   passwd* result;
   int rv = 0;
   do
   {
      rv = ::getpwuid_r(uid, &pw, &additional[0], additional.size(), &result);
      if (rv == ERANGE)
      {
         additional.resize(additional.size() * 2);
      }
   } while (rv == ERANGE);
#else
   MutexLock lock(g_getpwMutex);
   passwd* result = ::getpwuid(uid);
#endif  
   if (result)
   {
      ok = true;
      return result->pw_name;
   }
   ok = false;
   return "";
#endif
}

UserID
getUserId(const String& userName, bool& validUserName)
{
   validUserName = false;

#ifdef BLOCXX_WIN32
   // 20070625 Anton Afanasiev
   static DWORD uid[64]; // AA: do we really need for 'static' here?
   DWORD cbUid = sizeof(uid) * sizeof(DWORD);
   SID_NAME_USE snuOutVar; 
   DWORD cbDomainBufSize = MAX_PATH;
   TCHAR strDomainBuf[MAX_PATH] = {0};

   return (validUserName=::LookupAccountName(
         NULL, 
         userName.c_str(),
         &uid,
         &cbUid,
         strDomainBuf,
         &cbDomainBufSize,
         &snuOutVar))? &uid : NULL;

#else


#ifdef BLOCXX_HAVE_GETPWNAM_R
   size_t bufsize =
#ifdef _SC_GETPW_R_SIZE_MAX
      getSysconfValue(_SC_GETPW_R_SIZE_MAX, 10240);
#else
      1024;
#endif
   std::vector<char> buf(bufsize);
   struct passwd pwd;
   passwd* result = 0;
   int rv = 0;
   do
   {
      rv = ::getpwnam_r(userName.c_str(), &pwd, &buf[0], bufsize, &result);
      if (rv == ERANGE)
      {
         buf.resize(buf.size() * 2);
      }
   } while (rv == ERANGE);

   if (rv != 0)
   {
      return INVALID_USERID;
   }

#else
   MutexLock ml(g_getpwMutex);
   struct passwd* result;
   result = ::getpwnam(userName.c_str());
#endif
   if (result)
   {
      validUserName = true;
      return result->pw_uid;
   }
   return INVALID_USERID;
#endif
}
} // end namespace UserUtils
} // end namespace BLOCXX_NAMESPACE