Line data    Source code

       1             : // Copyright (c) 2021-2023  Made to Order Software Corp.  All Rights Reserved
       2             : //
       3             : // https://snapwebsites.org/project/snapdev
       4             : // contact@m2osw.com
       5             : //
       6             : // This program is free software: you can redistribute it and/or modify
       7             : // it under the terms of the GNU General Public License as published by
       8             : // the Free Software Foundation, either version 3 of the License, or
       9             : // (at your option) any later version.
      10             : //
      11             : // This program is distributed in the hope that it will be useful,
      12             : // but WITHOUT ANY WARRANTY; without even the implied warranty of
      13             : // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      14             : // GNU General Public License for more details.
      15             : //
      16             : // You should have received a copy of the GNU General Public License
      17             : // along with this program.  If not, see <https://www.gnu.org/licenses/>.
      18             : #pragma once
      19             : 
      20             : /** \file
      21             :  * \brief Read the list of groups a user is a part of.
      22             :  *
      23             :  * This function reads the list of groups a Unix user has been assigned to.
      24             :  * The results are saved in a standard container.
      25             :  */
      26             : 
      27             : // C++
      28             : //
      29             : #include    <set>
      30             : #include    <string>
      31             : #include    <vector>
      32             : 
      33             : 
      34             : // C
      35             : //
      36             : #include    <grp.h>
      37             : #include    <pwd.h>
      38             : 
      39             : 
      40             : 
      41             : namespace snapdev
      42             : {
      43             : 
      44             : 
      45             : /** \brief Get the set of user group names.
      46             :  *
      47             :  * This function creates a set of group names a user is a part of.
      48             :  *
      49             :  * \tparam ContainterT  The type of container used to output the tokens.
      50             :  * \param[in] user  The name of the user.
      51             :  *
      52             :  * \return A set of strings with the group names.
      53             :  */
      54             : template<class ContainerT>
      55           3 : ContainerT user_group_names(std::string const & user)
      56             : {
      57           3 :     struct passwd * pw(getpwnam(user.c_str()));
      58           3 :     if(pw == nullptr)
      59             :     {
      60           1 :         return ContainerT();
      61             :     }
      62             : 
      63           2 :     gid_t group(-1);
      64           2 :     int count(1);
      65           2 :     int r(getgrouplist(
      66             :               user.c_str()
      67             :             , pw->pw_gid
      68             :             , &group
      69             :             , &count));
      70             : 
      71           2 :     if(count <= 0)
      72             :     {
      73             :         return ContainerT();        // LCOV_EXCL_LINE
      74             :     }
      75             : 
      76           4 :     std::vector<gid_t> group_list(count);
      77           2 :     r = getgrouplist(
      78             :               user.c_str()
      79             :             , pw->pw_gid
      80             :             , group_list.data()
      81             :             , &count);
      82           2 :     if(r != count)
      83             :     {
      84             :         return ContainerT();        // LCOV_EXCL_LINE
      85             :     }
      86             : 
      87           2 :     ContainerT result;
      88          44 :     for(auto const gid : group_list)
      89             :     {
      90          42 :         struct group * grp(getgrgid(gid));
      91          42 :         if(grp == nullptr)  // I don't think this can happen... although it could be deleted under our feet
      92             :         {
      93             :             // Note: only the root user could really do this
      94             :             //       so that's why I had to exclude this line
      95             :             //
      96             :             result.insert(std::to_string(gid));        // LCOV_EXCL_LINE
      97             :         }
      98             :         else
      99             :         {
     100          42 :             result.insert(grp->gr_name);
     101             :         }
     102             :     }
     103             : 
     104           2 :     return result;
     105           2 : }
     106             : 
     107             : 
     108             : 
     109             : } // namespace snapdev
     110             : // vim: ts=4 sw=4 et