server/NetdConstants.h

/*
 * Copyright (C) 2012 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef _NETD_CONSTANTS_H
#define _NETD_CONSTANTS_H

#include <ifaddrs.h>
#include <netdb.h>
#include <stddef.h>
#include <stdint.h>

#include <mutex>
#include <string>

#include <private/android_filesystem_config.h>

const int MAX_SYSTEM_UID = AID_APP - 1;

// Referred from SHA256_DIGEST_LENGTH in boringssl
constexpr size_t SHA256_SIZE = 32;

enum IptablesTarget { V4, V6, V4V6 };

int execIptablesRestore(IptablesTarget target, const std::string& commands);
int execIptablesRestoreWithOutput(IptablesTarget target, const std::string& commands,
                                  std::string *output);
int execIptablesRestoreCommand(IptablesTarget target, const std::string& table,
                               const std::string& command, std::string *output);
bool isIfaceName(const std::string& name);
int parsePrefix(const char *prefix, uint8_t *family, void *address, int size, uint8_t *prefixlen);
void blockSigpipe();
void setCloseOnExec(const char *sock);

// TODO: use std::size() instead.
#define ARRAY_SIZE(a) (sizeof(a) / sizeof(*(a)))

#define __INT_STRLEN(i) sizeof(#i)
#define _INT_STRLEN(i) __INT_STRLEN(i)
#define INT32_STRLEN _INT_STRLEN(INT32_MIN)
#define UINT32_STRLEN _INT_STRLEN(UINT32_MAX)
#define UINT32_HEX_STRLEN sizeof("0x12345678")
#define IPSEC_IFACE_PREFIX "ipsec"

#define WARN_UNUSED_RESULT __attribute__((__warn_unused_result__))

const uid_t INVALID_UID = static_cast<uid_t>(-1);

constexpr char TCP_RMEM_PROC_FILE[] = "/proc/sys/net/ipv4/tcp_rmem";
constexpr char TCP_WMEM_PROC_FILE[] = "/proc/sys/net/ipv4/tcp_wmem";

struct AddrinfoDeleter {
    void operator()(struct addrinfo* p) const {
        if (p != nullptr) {
            freeaddrinfo(p);
        }
    }
};

typedef std::unique_ptr<struct addrinfo, struct AddrinfoDeleter> ScopedAddrinfo;


struct IfaddrsDeleter {
    void operator()(struct ifaddrs *p) const {
        if (p != nullptr) {
            freeifaddrs(p);
        }
    }
};

typedef std::unique_ptr<struct ifaddrs, struct IfaddrsDeleter> ScopedIfaddrs;

namespace android {
namespace net {

/**
 * This lock exists to make NetdNativeService RPCs (which come in on multiple Binder threads)
 * coexist with the commands in CommandListener.cpp. These are presumed not thread-safe because
 * CommandListener has only one user (NetworkManagementService), which is connected through a
 * FrameworkListener that passes in commands one at a time.
 */
extern std::mutex gBigNetdLock;

}  // namespace net
}  // namespace android

#endif  // _NETD_CONSTANTS_H