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/*
* Copyright (c) 2020-2021, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Assertions.h>
#include <AK/ByteBuffer.h>
#include <AK/JsonObject.h>
#include <AK/JsonValue.h>
#include <LibCore/ArgsParser.h>
#include <LibCore/DateTime.h>
#include <LibCore/File.h>
#include <LibCore/System.h>
#include <LibMain/Main.h>
#include <unistd.h>
ErrorOr<int> serenity_main(Main::Arguments arguments)
{
TRY(Core::System::pledge("stdio wpath cpath"));
TRY(Core::System::unveil("/var/run/utmp", "rwc"));
TRY(Core::System::unveil(nullptr, nullptr));
pid_t pid = 0;
bool flag_create = false;
bool flag_delete = false;
StringView tty_name;
StringView from;
Core::ArgsParser args_parser;
args_parser.add_option(flag_create, "Create entry", "create", 'c');
args_parser.add_option(flag_delete, "Delete entry", "delete", 'd');
args_parser.add_option(pid, "PID", "PID", 'p', "PID");
args_parser.add_option(from, "From", "from", 'f', "From");
args_parser.add_positional_argument(tty_name, "TTY name", "tty");
args_parser.parse(arguments);
if (flag_create && flag_delete) {
warnln("-c and -d are mutually exclusive");
return 1;
}
dbgln("Updating utmp from UID={} GID={} EGID={} PID={}", getuid(), getgid(), getegid(), pid);
auto file = TRY(Core::File::open("/var/run/utmp", Core::OpenMode::ReadWrite));
auto file_contents = file->read_all();
auto previous_json = TRY(JsonValue::from_string(file_contents));
JsonObject json;
if (!file_contents.is_empty()) {
if (!previous_json.is_object()) {
dbgln("Error: Could not parse JSON");
} else {
json = previous_json.as_object();
}
}
if (flag_create) {
JsonObject entry;
entry.set("pid", pid);
entry.set("uid", getuid());
entry.set("from", from);
entry.set("login_at", time(nullptr));
json.set(tty_name, move(entry));
} else {
VERIFY(flag_delete);
dbgln("Removing {} from utmp", tty_name);
json.remove(tty_name);
}
if (!file->seek(0)) {
dbgln("Seek failed");
return 1;
}
if (!file->truncate(0)) {
dbgln("Truncation failed");
return 1;
}
if (!file->write(json.to_string())) {
dbgln("Write failed");
return 1;
}
return 0;
}
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