ladybird/Userland/Utilities/groupdel.cpp
sin-ack c70f45ff44 Everywhere: Explicitly specify the size in StringView constructors
This commit moves the length calculations out to be directly on the
StringView users. This is an important step towards the goal of removing
StringView(char const*), as it moves the responsibility of calculating
the size of the string to the user of the StringView (which will prevent
naive uses causing OOB access).
2022-07-12 23:11:35 +02:00

103 lines
2.7 KiB
C++

/*
* Copyright (c) 2020, Fei Wu <f.eiwu@yahoo.com>
* Copyright (c) 2021, Brandon Pruitt <brapru@pm.me>
* Copyright (c) 2021, Maxime Friess <M4x1me@pm.me>
* Copyright (c) 2022, Umut İnan Erdoğan <umutinanerdogan62@gmail.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibCore/ArgsParser.h>
#include <LibCore/File.h>
#include <LibCore/System.h>
#include <LibMain/Main.h>
#include <grp.h>
#include <pwd.h>
#include <unistd.h>
ErrorOr<int> serenity_main(Main::Arguments arguments)
{
TRY(Core::System::pledge("stdio wpath rpath cpath fattr proc exec"));
TRY(Core::System::unveil("/etc/", "rwc"));
TRY(Core::System::unveil("/bin/rm", "x"));
char const* groupname = nullptr;
Core::ArgsParser args_parser;
args_parser.add_positional_argument(groupname, "Group name", "group");
args_parser.parse(arguments);
setgrent();
auto* g = getgrnam(groupname);
// Check if the group exists
if (!g) {
warnln("group {} does not exist", groupname);
return 6;
}
auto gid = g->gr_gid;
endgrent();
// Search if the group is the primary group of an user
setpwent();
struct passwd* pw;
for (pw = getpwent(); pw; pw = getpwent()) {
if (pw->pw_gid == gid)
break;
}
// If pw is not NULL it means we ended prematurely, aka. the group was found as primary group of an user
if (pw) {
warnln("cannot remove the primary group of user '{}'", pw->pw_name);
endpwent();
return 8;
}
endpwent();
// We can now safely delete the group
// Create a temporary group file
char temp_group[] = "/etc/group.XXXXXX";
StringView temp_group_view { temp_group, strlen(temp_group) };
auto unlink_temp_files = [&] {
if (Core::System::unlink(temp_group_view).is_error())
perror("unlink");
};
ArmedScopeGuard unlink_temp_files_guard = [&] {
unlink_temp_files();
};
int temp_group_fd = TRY(Core::System::mkstemp(temp_group));
FILE* temp_group_file = fdopen(temp_group_fd, "w");
if (!temp_group_file) {
perror("fdopen");
return 1;
}
setgrent();
for (auto* gr = getgrent(); gr; gr = getgrent()) {
if (gr->gr_gid != gid) {
if (putgrent(gr, temp_group_file) != 0) {
perror("failed to put an entry in the temporary group file");
return 1;
}
}
}
endgrent();
if (fclose(temp_group_file)) {
perror("fclose");
return 1;
}
TRY(Core::System::chmod(temp_group_view, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH));
TRY(Core::System::rename(temp_group_view, "/etc/group"sv));
unlink_temp_files_guard.disarm();
return 0;
}