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/*
* Copyright (c) 2022, Kenneth Myhra <kennethmyhra@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/CharacterTypes.h>
#include <AK/ScopeGuard.h>
#include <AK/StringBuilder.h>
#include <LibCore/Group.h>
#include <LibCore/System.h>
#include <LibCore/UmaskScope.h>
#include <errno.h>
#include <unistd.h>
namespace Core {
ErrorOr<DeprecatedString> Group::generate_group_file() const
{
StringBuilder builder;
char buffer[1024] = { 0 };
ScopeGuard grent_guard([] { endgrent(); });
setgrent();
while (true) {
auto group = TRY(Core::System::getgrent({ buffer, sizeof(buffer) }));
if (!group.has_value())
break;
if (group->gr_name == m_name)
builder.appendff("{}:x:{}:{}\n", m_name, m_id, DeprecatedString::join(',', m_members));
else {
Vector<DeprecatedString> members;
if (group->gr_mem) {
for (size_t i = 0; group->gr_mem[i]; ++i)
members.append(group->gr_mem[i]);
}
builder.appendff("{}:x:{}:{}\n", group->gr_name, group->gr_gid, DeprecatedString::join(',', members));
}
}
return builder.to_deprecated_string();
}
ErrorOr<void> Group::sync()
{
Core::UmaskScope umask_scope(0777);
auto new_group_file_content = TRY(generate_group_file());
char new_group_file[] = "/etc/group.XXXXXX";
auto new_group_file_view = StringView { new_group_file, sizeof(new_group_file) };
{
auto new_group_fd = TRY(Core::System::mkstemp(new_group_file));
ScopeGuard new_group_fd_guard([new_group_fd] { close(new_group_fd); });
TRY(Core::System::fchmod(new_group_fd, 0664));
auto nwritten = TRY(Core::System::write(new_group_fd, new_group_file_content.bytes()));
VERIFY(static_cast<size_t>(nwritten) == new_group_file_content.length());
}
TRY(Core::System::rename(new_group_file_view, "/etc/group"sv));
return {};
}
#if !defined(AK_OS_BSD_GENERIC) && !defined(AK_OS_ANDROID)
ErrorOr<void> Group::add_group(Group& group)
{
if (group.name().is_empty())
return Error::from_string_literal("Group name can not be empty.");
// A quick sanity check on group name
if (strpbrk(group.name().characters(), "\\/!@#$%^&*()~+=`:\n"))
return Error::from_string_literal("Group name has invalid characters.");
// Disallow names starting with '_', '-' or other non-alpha characters.
if (group.name().starts_with('_') || group.name().starts_with('-') || !is_ascii_alpha(group.name().characters()[0]))
return Error::from_string_literal("Group name has invalid characters.");
// Verify group name does not already exist
if (TRY(name_exists(group.name())))
return Error::from_string_literal("Group name already exists.");
// Sort out the group id for the group
if (group.id() > 0) {
if (TRY(id_exists(group.id())))
return Error::from_string_literal("Group ID already exists.");
} else {
gid_t group_id = 100;
while (true) {
if (!TRY(id_exists(group_id)))
break;
group_id++;
}
group.set_group_id(group_id);
}
auto gr = TRY(group.to_libc_group());
FILE* file = fopen("/etc/group", "a");
if (!file)
return Error::from_errno(errno);
ScopeGuard file_guard { [&] {
fclose(file);
} };
if (putgrent(&gr, file) < 0)
return Error::from_errno(errno);
return {};
}
#endif
ErrorOr<Vector<Group>> Group::all()
{
Vector<Group> groups;
char buffer[1024] = { 0 };
ScopeGuard grent_guard([] { endgrent(); });
setgrent();
while (true) {
auto group = TRY(Core::System::getgrent({ buffer, sizeof(buffer) }));
if (!group.has_value())
break;
Vector<DeprecatedString> members;
if (group->gr_mem) {
for (size_t i = 0; group->gr_mem[i]; ++i)
members.append(group->gr_mem[i]);
}
groups.append({ group->gr_name, group->gr_gid, move(members) });
}
return groups;
}
Group::Group(DeprecatedString name, gid_t id, Vector<DeprecatedString> members)
: m_name(move(name))
, m_id(id)
, m_members(move(members))
{
}
ErrorOr<bool> Group::name_exists(StringView name)
{
return TRY(Core::System::getgrnam(name)).has_value();
}
ErrorOr<bool> Group::id_exists(gid_t id)
{
return TRY(Core::System::getgrgid(id)).has_value();
}
// NOTE: struct group returned from this function cannot outlive an instance of Group.
ErrorOr<struct group> Group::to_libc_group()
{
struct group gr;
gr.gr_name = const_cast<char*>(m_name.characters());
gr.gr_passwd = const_cast<char*>("x");
gr.gr_gid = m_id;
gr.gr_mem = nullptr;
// FIXME: A better solution would surely be not using a static here
// NOTE: This now means that there cannot be multiple struct groups at the same time, because only one gr.gr_mem can ever be valid at the same time.
// NOTE: Not using a static here would result in gr.gr_mem being freed up on exit from this function.
static Vector<char*> members;
members.clear_with_capacity();
if (m_members.size() > 0) {
TRY(members.try_ensure_capacity(m_members.size() + 1));
for (auto member : m_members)
members.unchecked_append(const_cast<char*>(member.characters()));
members.unchecked_append(nullptr);
gr.gr_mem = const_cast<char**>(members.data());
}
return gr;
}
}
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