1  // SPDX-FileCopyrightText: Copyright (C) 2026 Marek Küthe <m.k@mk16.de>
 2  //
 3  // SPDX-License-Identifier: GPL-3.0-or-later
 4  
 5  #include "posix_wrapper.hpp"
 6  
 7  int PosixWrapper::dup(const int oldfd)
 8  {
 9      const int result = ::dup(oldfd);
10      if (result < 0)
11      {
12          throw std::system_error(errno,
13                                  std::generic_category(),
14                                  "Failed to duplicate file descriptor.");
15      }
16      return result;
17  }
18  
19  #ifdef HAVE_SETUGID
20  void PosixWrapper::set_uid(const uid_t uid)
21  {
22      const int result = ::setuid(uid);
23      if (result != 0)
24      {
25          throw std::system_error(
26              errno, std::generic_category(), "Failed to set uid.");
27      }
28  }
29  
30  void PosixWrapper::set_gid(const gid_t uid)
31  {
32      const int result = ::setgid(uid);
33      if (result != 0)
34      {
35          throw std::system_error(
36              errno, std::generic_category(), "Failed to set gid.");
37      }
38  }
39  
40  uid_t PosixWrapper::username_to_uid(const std::string& username)
41  {
42      // This function is called in a single-threaded manner in crazytrace.
43      // Therefore, it may be thread-unsafe.
44      struct passwd * entry =
45          ::getpwnam(username.c_str()); // NOLINT(concurrency-mt-unsafe)
46      if (entry == nullptr)
47      {
48          throw std::system_error(
49              errno, std::generic_category(), "Failed to get uid for username.");
50      }
51      return entry->pw_uid;
52  }
53  
54  gid_t PosixWrapper::groupname_to_gid(const std::string& groupname)
55  {
56      // This function is called in a single-threaded manner in crazytrace.
57      // Therefore, it may be thread-unsafe.
58      struct group * entry =
59          ::getgrnam(groupname.c_str()); // NOLINT(concurrency-mt-unsafe)
60      if (entry == nullptr)
61      {
62          throw std::system_error(
63              errno, std::generic_category(), "Failed to get gid for groupname.");
64      }
65      return entry->gr_gid;
66  }
67  #endif