Kernel/LibC: Implement {get,set}sockopt()

These are pretty much dummy functions in the kernel side. Only case that
is handled is SOL_SOCKET with SO_ERROR. This is hard coded to return no
error. Network stack is currently synchronous, so all errors are already
reported through synchronous network functions.

kernel/include/kernel/Process.h

@@ -120,6 +120,8 @@ namespace Kernel
 
 		BAN::ErrorOr<long> sys_socket(int domain, int type, int protocol);
 		BAN::ErrorOr<long> sys_getsockname(int socket, sockaddr* address, socklen_t* address_len);
+		BAN::ErrorOr<long> sys_getsockopt(int socket, int level, int option_name, void* option_value, socklen_t* option_len);
+		BAN::ErrorOr<long> sys_setsockopt(int socket, int level, int option_name, const void* option_value, socklen_t option_len);
 
 		BAN::ErrorOr<long> sys_accept(int socket, sockaddr* address, socklen_t* address_len);
 		BAN::ErrorOr<long> sys_bind(int socket, const sockaddr* address, socklen_t address_len);

kernel/kernel/Process.cpp

@@ -925,6 +925,42 @@ namespace Kernel
 		return 0;
 	}
 
+	BAN::ErrorOr<long> Process::sys_getsockopt(int socket, int level, int option_name, void* option_value, socklen_t* option_len)
+	{
+		LockGuard _(m_process_lock);
+		TRY(validate_pointer_access(option_len, sizeof(option_len)));
+		TRY(validate_pointer_access(option_value, *option_len));
+
+		auto inode = TRY(m_open_file_descriptors.inode_of(socket));
+		if (!inode->mode().ifsock())
+			return BAN::Error::from_errno(ENOTSOCK);
+
+		// Because all networking is synchronous, there can not be errors to report
+		if (level == SOL_SOCKET && option_name == SO_ERROR)
+		{
+			if (*option_len)
+				*reinterpret_cast<uint8_t*>(option_value) = 0;
+			*option_len = BAN::Math::min<socklen_t>(*option_len, sizeof(int));
+			return 0;
+		}
+
+		dprintln("SYS_GETSOCKOPT {}, {}, {}, {}, {}", socket, level, option_name, option_value, option_len);
+		return BAN::Error::from_errno(ENOTSUP);
+	}
+
+	BAN::ErrorOr<long> Process::sys_setsockopt(int socket, int level, int option_name, const void* option_value, socklen_t option_len)
+	{
+		LockGuard _(m_process_lock);
+		TRY(validate_pointer_access(option_value, option_len));
+
+		auto inode = TRY(m_open_file_descriptors.inode_of(socket));
+		if (!inode->mode().ifsock())
+			return BAN::Error::from_errno(ENOTSOCK);
+
+		dprintln("SYS_GETSOCKOPT {}, {}, {}, {}, {}", socket, level, option_name, option_value, option_len);
+		return BAN::Error::from_errno(ENOTSUP);
+	}
+
 	BAN::ErrorOr<long> Process::sys_accept(int socket, sockaddr* address, socklen_t* address_len)
 	{
 		if (address && !address_len)

libc/include/sys/syscall.h

@@ -79,6 +79,8 @@ __BEGIN_DECLS
 	O(SYS_SMO_MAP,			smo_map)		\
 	O(SYS_ISATTY,			isatty)			\
 	O(SYS_GETSOCKNAME,		getsockname)	\
+	O(SYS_GETSOCKOPT,		getsockopt)		\
+	O(SYS_SETSOCKOPT,		setsockopt)		\
 
 enum Syscall
 {

libc/sys/socket.cpp

@@ -67,3 +67,13 @@ int getsockname(int socket, struct sockaddr* __restrict address, socklen_t* __re
 {
 	return syscall(SYS_GETSOCKNAME, socket, address, address_len);
 }
+
+int getsockopt(int socket, int level, int option_name, void* __restrict option_value, socklen_t* __restrict option_len)
+{
+	return syscall(SYS_GETSOCKOPT, socket, level, option_name, option_value, option_len);
+}
+
+int setsockopt(int socket, int level, int option_name, const void* option_value, socklen_t option_len)
+{
+	return syscall(SYS_SETSOCKOPT, socket, level, option_name, option_value, option_len);
+}