From e114258821760cd1b550fc86bf3657b1f9af62f2 Mon Sep 17 00:00:00 2001
From: Benny Baumann <BenBE@geshi.org>
Date: Sun, 3 Jan 2021 16:27:46 +0100
Subject: [PATCH] add: sockaddr handling
---
src/net/socketaddress.hpp | 134 ++++++++++++++++++++++++++++++++++++++
1 file changed, 134 insertions(+)
create mode 100644 src/net/socketaddress.hpp
diff --git a/src/net/socketaddress.hpp b/src/net/socketaddress.hpp
new file mode 100644
index 0000000..7a32f28
--- /dev/null
+++ b/src/net/socketaddress.hpp
@@ -0,0 +1,134 @@
+#pragma once
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+
+#include <netinet/in.h>
+#include <netinet/ip.h>
+#include <netinet/ip6.h>
+
+#include <functional>
+
+#include "net/netio_exception.hpp"
+
+#ifdef __linux__
+#include <linux/netlink.h>
+#endif
+
+namespace rmrf::net {
+
+template <typename T>
+struct family_map {};
+
+template <>
+struct family_map<sockaddr_in> {
+ static constexpr int sa_family = AF_INET;
+ static constexpr auto sa_family_field = &sockaddr_in::sin_family;
+};
+
+template <>
+struct family_map<sockaddr_in6> {
+ static constexpr int sa_family = AF_INET6;
+ static constexpr auto sa_family_field = &sockaddr_in6::sin6_family;
+};
+
+template <>
+struct family_map<sockaddr_un> {
+ static constexpr int sa_family = AF_UNIX;
+ static constexpr auto sa_family_field = &sockaddr_un::sun_family;
+};
+
+template <>
+struct family_map<sockaddr_nl> {
+ static constexpr int sa_family = AF_NETLINK;
+ static constexpr auto sa_family_field = &sockaddr_nl::nl_family;
+};
+
+template <typename, typename = void>
+struct has_field : std::false_type {};
+
+template <typename T>
+struct has_field<T, std::void_t<decltype(family_map<T>::sa_family)>> : std::is_convertible<decltype(family_map<T>::sa_family), int> {};
+
+class socketaddr {
+private:
+ sockaddr_storage addr;
+ socklen_t len;
+
+public:
+ socketaddr();
+
+ template <typename T, typename std::enable_if<has_field<T>::value, T>::type * = nullptr>
+ explicit socketaddr(T *other) : addr{}, len{} {
+ if (other->*(family_map<T>::sa_family_field) != family_map<T>::sa_family) {
+ throw netio_exception("Address family mismatch in sockaddr structure.");
+ }
+
+ memcpy(&addr, other, sizeof(T));
+ len = sizeof(T);
+ }
+
+ template <typename T, typename std::enable_if<has_field<T>::value, T>::type * = nullptr>
+ explicit socketaddr(const T& other) : addr{}, len{} {
+ if (other.*(family_map<T>::sa_family_field) != family_map<T>::sa_family) {
+ throw netio_exception("Address family mismatch in sockaddr structure.");
+ }
+
+ memcpy(&addr, &other, sizeof(T));
+ len = sizeof(T);
+ }
+
+ template <typename T>
+ socketaddr &operator=(T *rhs) {
+ if (rhs->*(family_map<T>::sa_family_field) != family_map<T>::sa_family) {
+ throw netio_exception("Address family mismatch in sockaddr structure.");
+ }
+
+ memcpy(&addr, rhs, sizeof(T));
+ len = sizeof(T);
+ }
+
+ socketaddr &operator=(sockaddr_storage *rhs) {
+ return *this = (sockaddr*)rhs;
+ }
+
+ socketaddr& operator=(sockaddr *rhs) {
+ switch(rhs->sa_family) {
+ case AF_INET:
+ return *this = (sockaddr_in *)rhs;
+ case AF_INET6:
+ return *this = (sockaddr_in6 *)rhs;
+ case AF_UNIX:
+ return *this = (sockaddr_un *)rhs;
+ case AF_NETLINK:
+ return *this = (sockaddr_nl *)rhs;
+ default:
+ throw netio_exception("Trying to assign unknown address family");
+ }
+ };
+
+ int family() const {
+ return addr.ss_family;
+ }
+
+ template <typename T>
+ operator T*() const {
+ if (addr.ss_family != family_map<T>::sa_family) {
+ throw netio_exception("Cannot convert address family of stored sockaddr structure.");
+ }
+
+ return (T*)&addr;
+ }
+
+ sockaddr* ptr() const {
+ return (sockaddr*)&addr;
+ }
+
+ socklen_t size() const {
+ return len;
+ }
+
+};
+
+}
--
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