mpd/src/net/LocalSocketAddress.hxx

130 lines
3.0 KiB
C++

// SPDX-License-Identifier: BSD-2-Clause
// author: Max Kellermann <max.kellermann@gmail.com>
#pragma once
#include "SocketAddress.hxx" // IWYU pragma: export
#include <algorithm> // for std::copy()
#include <stdexcept> // for std::length_error
#include <string_view>
#include <sys/un.h>
/**
* An OO wrapper for struct sockaddr_un.
*/
class LocalSocketAddress {
friend class SocketDescriptor;
public:
typedef SocketAddress::size_type size_type;
private:
size_type size;
struct sockaddr_un address;
public:
constexpr LocalSocketAddress() noexcept = default;
constexpr explicit LocalSocketAddress(std::string_view path) noexcept
:address{} {
SetLocal(path);
}
constexpr operator SocketAddress() const noexcept {
return SocketAddress{*this, size};
}
constexpr operator struct sockaddr *() noexcept {
return (struct sockaddr *)(void *)&address;
}
constexpr operator const struct sockaddr *() const noexcept {
return (const struct sockaddr *)(const void *)&address;
}
constexpr size_type GetCapacity() const noexcept {
return sizeof(address);
}
constexpr size_type GetSize() const noexcept {
return size;
}
constexpr int GetFamily() const noexcept {
return address.sun_family;
}
constexpr bool IsDefined() const noexcept {
return GetFamily() != AF_UNSPEC;
}
constexpr void Clear() noexcept {
address.sun_family = AF_UNSPEC;
}
/**
* @see SocketAddress::GetLocalRaw()
*/
constexpr std::string_view GetLocalRaw() const noexcept {
if (GetFamily() != AF_LOCAL)
return {};
const auto start = (const char *)&address;
const auto path = address.sun_path;
const size_t header_size = path - start;
if (size < size_type(header_size))
/* malformed address */
return {};
return {path, size - header_size};
}
/**
* @see SocketAddress::GetLocalPath()
*/
[[nodiscard]] [[gnu::pure]]
const char *GetLocalPath() const noexcept;
/**
* Make this a "local" address (UNIX domain socket). If the path
* begins with a '@', then the rest specifies an "abstract" local
* address.
*/
constexpr LocalSocketAddress &SetLocal(std::string_view path) {
const bool is_abstract = path.starts_with('@');
/* sun_path must be null-terminated unless it's an abstract
socket */
const size_t path_length = path.size() + !is_abstract;
if (path_length > sizeof(address.sun_path))
throw std::length_error{"Path is too long"};
size = sizeof(address) - sizeof(address.sun_path) + path_length;
address.sun_family = AF_LOCAL;
auto out = std::copy(path.begin(), path.end(), address.sun_path);
if (is_abstract)
address.sun_path[0] = 0;
else
*out = 0;
return *this;
}
[[nodiscard]] [[gnu::pure]]
std::span<const std::byte> GetSteadyPart() const noexcept;
[[nodiscard]] [[gnu::pure]]
bool operator==(SocketAddress other) const noexcept {
return static_cast<const SocketAddress>(*this) == other;
}
[[nodiscard]] [[gnu::pure]]
bool operator!=(SocketAddress other) const noexcept {
return !(*this == other);
}
};