ladybird/Userland/Utilities/mount.cpp
Andreas Kling 587f9af960 AK: Make JSON parser return ErrorOr<JsonValue> (instead of Optional)
Also add slightly richer parse errors now that we can include a string
literal with returned errors.

This will allow us to use TRY() when working with JSON data.
2021-11-17 00:21:10 +01:00

199 lines
5.6 KiB
C++

/*
* Copyright (c) 2019-2020, Sergey Bugaev <bugaevc@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Assertions.h>
#include <AK/JsonArray.h>
#include <AK/JsonObject.h>
#include <AK/JsonValue.h>
#include <AK/Optional.h>
#include <LibCore/ArgsParser.h>
#include <LibCore/File.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
static int parse_options(StringView options)
{
int flags = 0;
Vector<StringView> parts = options.split_view(',');
for (auto& part : parts) {
if (part == "defaults")
continue;
else if (part == "nodev")
flags |= MS_NODEV;
else if (part == "noexec")
flags |= MS_NOEXEC;
else if (part == "nosuid")
flags |= MS_NOSUID;
else if (part == "bind")
flags |= MS_BIND;
else if (part == "ro")
flags |= MS_RDONLY;
else if (part == "remount")
flags |= MS_REMOUNT;
else
warnln("Ignoring invalid option: {}", part);
}
return flags;
}
static bool is_source_none(const char* source)
{
return !strcmp("none", source);
}
static int get_source_fd(const char* source)
{
if (is_source_none(source))
return -1;
int fd = open(source, O_RDWR);
if (fd < 0)
fd = open(source, O_RDONLY);
if (fd < 0) {
int saved_errno = errno;
auto message = String::formatted("Failed to open: {}\n", source);
errno = saved_errno;
perror(message.characters());
}
return fd;
}
static bool mount_all()
{
// Mount all filesystems listed in /etc/fstab.
dbgln("Mounting all filesystems...");
auto fstab = Core::File::construct("/etc/fstab");
if (!fstab->open(Core::OpenMode::ReadOnly)) {
warnln("Failed to open {}: {}", fstab->name(), fstab->error_string());
return false;
}
bool all_ok = true;
while (fstab->can_read_line()) {
auto line = fstab->read_line();
// Skip comments and blank lines.
if (line.is_empty() || line.starts_with("#"))
continue;
Vector<String> parts = line.split('\t');
if (parts.size() < 3) {
warnln("Invalid fstab entry: {}", line);
all_ok = false;
continue;
}
const char* mountpoint = parts[1].characters();
const char* fstype = parts[2].characters();
int flags = parts.size() >= 4 ? parse_options(parts[3]) : 0;
if (strcmp(mountpoint, "/") == 0) {
dbgln("Skipping mounting root");
continue;
}
const char* filename = parts[0].characters();
int fd = get_source_fd(filename);
dbgln("Mounting {} ({}) on {}", filename, fstype, mountpoint);
int rc = mount(fd, mountpoint, fstype, flags);
if (rc != 0) {
warnln("Failed to mount {} (FD: {}) ({}) on {}: {}", filename, fd, fstype, mountpoint, strerror(errno));
all_ok = false;
continue;
}
}
return all_ok;
}
static bool print_mounts()
{
// Output info about currently mounted filesystems.
auto df = Core::File::construct("/proc/df");
if (!df->open(Core::OpenMode::ReadOnly)) {
warnln("Failed to open {}: {}", df->name(), df->error_string());
return false;
}
auto content = df->read_all();
auto json = JsonValue::from_string(content).release_value_but_fixme_should_propagate_errors();
json.as_array().for_each([](auto& value) {
auto& fs_object = value.as_object();
auto class_name = fs_object.get("class_name").to_string();
auto mount_point = fs_object.get("mount_point").to_string();
auto source = fs_object.get("source").as_string_or("none");
auto readonly = fs_object.get("readonly").to_bool();
auto mount_flags = fs_object.get("mount_flags").to_int();
out("{} on {} type {} (", source, mount_point, class_name);
if (readonly || mount_flags & MS_RDONLY)
out("ro");
else
out("rw");
if (mount_flags & MS_NODEV)
out(",nodev");
if (mount_flags & MS_NOEXEC)
out(",noexec");
if (mount_flags & MS_NOSUID)
out(",nosuid");
if (mount_flags & MS_BIND)
out(",bind");
outln(")");
});
return true;
}
int main(int argc, char** argv)
{
const char* source = nullptr;
const char* mountpoint = nullptr;
const char* fs_type = nullptr;
const char* options = nullptr;
bool should_mount_all = false;
Core::ArgsParser args_parser;
args_parser.add_positional_argument(source, "Source path", "source", Core::ArgsParser::Required::No);
args_parser.add_positional_argument(mountpoint, "Mount point", "mountpoint", Core::ArgsParser::Required::No);
args_parser.add_option(fs_type, "File system type", nullptr, 't', "fstype");
args_parser.add_option(options, "Mount options", nullptr, 'o', "options");
args_parser.add_option(should_mount_all, "Mount all file systems listed in /etc/fstab", nullptr, 'a');
args_parser.parse(argc, argv);
if (should_mount_all) {
return mount_all() ? 0 : 1;
}
if (!source && !mountpoint)
return print_mounts() ? 0 : 1;
if (source && mountpoint) {
if (!fs_type)
fs_type = "ext2";
int flags = options ? parse_options(options) : 0;
int fd = get_source_fd(source);
if (mount(fd, mountpoint, fs_type, flags) < 0) {
perror("mount");
return 1;
}
return 0;
}
args_parser.print_usage(stderr, argv[0]);
return 1;
}