Line data    Source code

       1             : // Copyright (c) 2021-2022  Made to Order Software Corp.  All Rights Reserved
       2             : //
       3             : // This program is free software; you can redistribute it and/or modify
       4             : // it under the terms of the GNU General Public License as published by
       5             : // the Free Software Foundation; either version 2 of the License, or
       6             : // (at your option) any later version.
       7             : //
       8             : // This program is distributed in the hope that it will be useful,
       9             : // but WITHOUT ANY WARRANTY; without even the implied warranty of
      10             : // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      11             : // GNU General Public License for more details.
      12             : //
      13             : // You should have received a copy of the GNU General Public License along
      14             : // with this program; if not, write to the Free Software Foundation, Inc.,
      15             : // 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
      16             : #pragma once
      17             : 
      18             : // C++ lib
      19             : //
      20             : #include    <set>
      21             : #include    <string>
      22             : #include    <vector>
      23             : 
      24             : 
      25             : // C lib
      26             : //
      27             : #include    <grp.h>
      28             : #include    <pwd.h>
      29             : 
      30             : 
      31             : 
      32             : namespace snapdev
      33             : {
      34             : 
      35             : 
      36             : /** \brief Get the set of user group names.
      37             :  *
      38             :  * This function creates a set of group names a user is a part of.
      39             :  *
      40             :  * \tparam ContainterT  The type of container used to output the tokens.
      41             :  * \param[in] user  The name of the user.
      42             :  *
      43             :  * \return A set of strings with the group names.
      44             :  */
      45             : template<class ContainerT>
      46           3 : ContainerT user_group_names(std::string const & user)
      47             : {
      48           3 :     struct passwd * pw(getpwnam(user.c_str()));
      49           3 :     if(pw == nullptr)
      50             :     {
      51           1 :         return ContainerT();
      52             :     }
      53             : 
      54           2 :     gid_t group(-1);
      55           2 :     int count(1);
      56           2 :     int r(getgrouplist(
      57             :               user.c_str()
      58             :             , pw->pw_gid
      59             :             , &group
      60             :             , &count));
      61             : 
      62           2 :     if(count <= 0)
      63             :     {
      64             :         return ContainerT();        // LCOV_EXCL_LINE
      65             :     }
      66             : 
      67           4 :     std::vector<gid_t> group_list(count);
      68           2 :     r = getgrouplist(
      69             :               user.c_str()
      70             :             , pw->pw_gid
      71             :             , group_list.data()
      72             :             , &count);
      73           2 :     if(r != count)
      74             :     {
      75             :         return ContainerT();        // LCOV_EXCL_LINE
      76             :     }
      77             : 
      78           4 :     ContainerT result;
      79          44 :     for(auto const gid : group_list)
      80             :     {
      81          42 :         struct group * grp(getgrgid(gid));
      82          42 :         if(grp == nullptr)  // I don't think this can happen... although it could be deleted under our feet
      83             :         {
      84             :             // Note: only the root user could really do this
      85             :             //       so that's why I had to exclude this line
      86             :             //
      87             :             result.insert(std::to_string(gid));        // LCOV_EXCL_LINE
      88             :         }
      89             :         else
      90             :         {
      91          42 :             result.insert(grp->gr_name);
      92             :         }
      93             :     }
      94             : 
      95           2 :     return result;
      96             : }
      97             : 
      98             : 
      99             : 
     100             : } // namespace snapdev
     101             : // vim: ts=4 sw=4 et