User.cpp

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// DUNE DAQ modification notice:
// This file has been modified from the original ATLAS system source for the DUNE DAQ project.
// Fork baseline commit: system-00-00-20 (2020-09-25).
// Renamed since fork: yes (from src/User.cxx to src/User.cpp).
 
/*
 *  User.cxx
 *  OksSystem
 *
 *  Created by Matthias Wiesmann on 03.02.05.
 *  Copyright 2005 CERN. All rights reserved.
 *
 */
 
#include <pwd.h>
 
#include <iostream>
#include <sstream>
 
#include "ers/ers.hpp"
 
#include "okssystem/User.hpp"
#include "okssystem/exceptions.hpp"
 
const OksSystem::User OksSystem::User::ROOT(0);
 
OksSystem::User::User() throw()
{
  m_user_id = ::getuid();
} // User
 
OksSystem::User::User(uid_t user_id) throw()
{
  m_user_id = user_id;
} // User
 
OksSystem::User::User(const std::string& s_name)
{
 
  errno = 0;
  long bufSize = ::sysconf(_SC_GETPW_R_SIZE_MAX);
 
  if (bufSize == -1) {
    if (errno == 0) {
      bufSize = 1024;
    } else {
      std::string message = "with argument _SC_GETPW_R_SIZE_MAX while getting info about user " + s_name;
      throw OksSystem::OksSystemCallIssue(ERS_HERE, errno, "sysconf", message.c_str());
    }
  }
 
  struct passwd pwd;
  struct passwd* result;
  char* buf = new char[bufSize];
  errno = 0;
  int res = ::getpwnam_r(s_name.c_str(), &pwd, buf, bufSize, &result);
  if (res == 0) {
    if (result != 0) {
      m_user_id = result->pw_uid;
    } else {
      delete[] buf;
      std::string eMsg = "User " + s_name + " not found";
      throw OksSystem::OksSystemCallIssue(ERS_HERE, errno, "getpwnam_r", eMsg.c_str());
    }
  } else {
    delete[] buf;
    std::string message = "while getting info about user " + s_name;
    throw OksSystem::OksSystemCallIssue(ERS_HERE, res, "getpwnam_r", message.c_str());
  }
  delete[] buf;
 
  m_user_name = s_name;
} // User
 
OksSystem::User::User(const User& other) throw()
{
  m_user_id = other.m_user_id;
  m_user_name = other.m_user_name;
} // User
 
// Operators
// =========
 
OksSystem::User::operator uid_t() const throw()
{
  return m_user_id;
} // uid_t
 
OksSystem::User::operator std::string() const
{
  return name();
} // string
 
OksSystem::User::operator const char*() const
{
  if (m_user_name.empty()) {
    resolve();
  }
  return m_user_name.c_str();
} // char*
 
//  Methods
// =========

 
uid_t
OksSystem::User::identity() const throw()
{
  return m_user_id;
} // identity

 
void
OksSystem::User::resolve() const
{
 
  errno = 0;
  long bufSize = ::sysconf(_SC_GETPW_R_SIZE_MAX);
 
  if (bufSize == -1) {
    if (errno == 0) {
      bufSize = 1024;
    } else {
      std::ostringstream message;
      message << "with argument _SC_GETPW_R_SIZE_MAX while getting info about user with id " << m_user_id;
      throw OksSystem::OksSystemCallIssue(ERS_HERE, errno, "sysconf", message.str().c_str());
    }
  }
 
  struct passwd pwd;
  struct passwd* result;
  char* buf = new char[bufSize];
  errno = 0;
  int res = ::getpwuid_r(m_user_id, &pwd, buf, bufSize, &result);
  if (res == 0) {
    if (result != 0) {
      m_user_name = std::string(result->pw_name);
      m_user_home = std::string(result->pw_dir);
      m_user_real_name = std::string(result->pw_gecos);
    } else {
      delete[] buf;
      std::ostringstream eMsg;
      eMsg << "User " << m_user_id << " not found";
      throw OksSystem::OksSystemCallIssue(ERS_HERE, errno, "getpwuid_r", eMsg.str().c_str());
    }
  } else {
    delete[] buf;
    std::ostringstream message;
    message << "while getting info about user with id " << m_user_id;
    throw OksSystem::OksSystemCallIssue(ERS_HERE, res, "getpwnam_r", message.str().c_str());
  }
  delete[] buf;
 
} //

 
void
OksSystem::User::resolve_safe() const throw()
{
 
  errno = 0;
  long bufSize = ::sysconf(_SC_GETPW_R_SIZE_MAX);
 
  if (bufSize == -1) {
    if (errno == 0) {
      bufSize = 1024;
    } else {
      m_user_name = "unknown";
      m_user_home = "unknown";
      m_user_real_name = "unknown";
      return;
    }
  }
 
  struct passwd pwd;
  struct passwd* result;
  char* buf = new char[bufSize];
  int res = ::getpwuid_r(m_user_id, &pwd, buf, bufSize, &result);
  if (res == 0) {
    if (result != 0) {
      m_user_name = std::string(result->pw_name);
      m_user_home = std::string(result->pw_dir);
      m_user_real_name = std::string(result->pw_gecos);
    } else {
      m_user_name = "unknown";
      m_user_home = "unknown";
      m_user_real_name = "unknown";
    }
  } else {
    m_user_name = "unknown";
    m_user_home = "unknown";
    m_user_real_name = "unknown";
  }
  delete[] buf;
 
} // resolve_safe

 
const std::string&
OksSystem::User::name() const
{
  if (m_user_name.empty()) {
    resolve();
  }
  return m_user_name;
} // name

 
const std::string&
OksSystem::User::name_safe() const throw()
{
  if (m_user_name.empty()) {
    resolve_safe();
  }
  return m_user_name;
} // name

 
const std::string&
OksSystem::User::home() const
{
  if (m_user_home.empty()) {
    resolve();
  }
  return m_user_home;
} // home

 
const std::string&
OksSystem::User::real_name() const
{
  if (m_user_real_name.empty()) {
    resolve();
  }
  return m_user_real_name;
} // real_name

 
void
OksSystem::User::setuid() const
{
  const int status = ::setuid(m_user_id);
  if (status < 0) {
    std::ostringstream message;
    message << "while setting the effective user ID to " << m_user_id << "(" << this->name_safe() << ")";
    throw OksSystem::OksSystemCallIssue(ERS_HERE, errno, "setuid", message.str().c_str());
  }
} // setuid

 
std::ostream&
operator<<(std::ostream& stream, const OksSystem::User& user) throw()
{
  unsigned int i = (unsigned int)user.identity();
  const std::string name = user.name_safe();
  stream << name << '(' << i << ')';
  return stream;
} // operator<<

 
bool
operator==(const OksSystem::User& a, const OksSystem::User& b) throw()
{
  return a.identity() == b.identity();
} //

 
bool
operator!=(const OksSystem::User& a, const OksSystem::User& b) throw()
{
  return a.identity() != b.identity();
} //