本文分享自华为云社区《华为云短信服务教你用C++实现Smgp协议》，作者：张俭。

引言&协议概述

中国联合网络通信有限公司短消息网关系统接口协议（SGIP）是中国网通为实现短信业务而制定的一种通信协议，全称叫做Short Message Gateway Interface Protocol，用于在短消息网关（SMG）和服务提供商（SP）之间、短消息网关（SMG）和短消息网关（SMG）之间通信。

Perl的IO::Async模块提供了一套简洁的异步IO编程模型。

SGIP 协议基于客户端/服务端模型工作。由客户端（短信应用，如手机，应用程序等）先和短信网关（SMG Short Message Gateway）建立起 TCP 长连接，并使用 SGIP 命令与SMG进行交互，实现短信的发送和接收。在SGIP协议中，无需同步等待响应就可以发送下一个指令，实现者可以根据自己的需要，实现同步、异步两种消息传输模式，满足不同场景下的性能要求。

时序图

连接成功，发送短信

 

 

 

连接成功，从SMGW接收到短信

 

 

 

协议帧介绍

SGIP Header

• Message Length：长度为4字节，整个PDU的长度，包括Header和Body。
• Command ID：长度为4字节，用于标识PDU的类型（例如，Login、Submit等）。
• Sequence Number：长度为8字节，序列号，用来匹配请求和响应。

使用C++实现SMGP协议栈里的建立连接

├── CMakeLists.txt
├── examples
│   └── smgp_client_login_example.cpp
└── include
    └── sgipcpp
        ├── BoundAtomic.h
        ├── Client.h
        ├── Protocol.h
        └── impl
            ├── BoundAtomic.cpp
            ├── Client.cpp
            └── Protocol.cpp

CMakeLists.txt：用来生成Makefile和编译项目

examples：存放示例代码

• smgp_client_login_example.cpp：存放Smgp的login样例

include/sgipcpp：包含所有的C++头文件和实现文件

• BoundAtomic.h：递增工具类，用来生成SequenceId
• Client.h：Smgp定义，负责与Smgp服务进行通信，例如建立连接、发送短信等
• Protocol.h：存放PDU，编解码等
• impl/BoundAtomic.cpp：BoundAtomic类的实现
• impl/Client.cpp：Client类的实现
• impl/Protocol.cpp：Protocol中相关函数的实现

实现SequenceId递增

SequenceId是从1到0x7FFFFFFF的值，使用**BoundAtomic**类实现递增：

头文件

#ifndef BOUNDATOMIC_H
#define BOUNDATOMIC_H

#include <atomic>
#include <cassert>

class BoundAtomic {
public:
    BoundAtomic(int min, int max);
    int next_val();

private:
    int min_;
    int max_;
    std::atomic<int> integer_;
};

#endif //BOUNDATOMIC_H

内容

#include "sgipcpp/BoundAtomic.h"

BoundAtomic::BoundAtomic(int min, int max) : min_(min), max_(max), integer_(min) {
    assert(min <= max);
}

int BoundAtomic::next_val() {
    int current = integer_.load();
    int next;
    do {
        next = current >= max_ ? min_ : current + 1;
    } while (!integer_.compare_exchange_strong(current, next));

    return next;
}

实现SMGP PDU以及编解码函数

在**Protocol.h**中定义SMGP PDU以及编解码函数：

头文件

#ifndef PROTOCOL_H
#define PROTOCOL_H

#include <cstdint>
#include <vector>

constexpr uint32_t SGIP_BIND = 0x00000001;
constexpr uint32_t SGIP_BIND_RESP = 0x80000001;
constexpr uint32_t SGIP_UNBIND = 0x00000002;
constexpr uint32_t SGIP_UNBIND_RESP = 0x80000002;
constexpr uint32_t SGIP_SUBMIT = 0x00000003;
constexpr uint32_t SGIP_SUBMIT_RESP = 0x80000003;
constexpr uint32_t SGIP_DELIVER = 0x00000004;
constexpr uint32_t SGIP_DELIVER_RESP = 0x80000004;
constexpr uint32_t SGIP_REPORT = 0x00000005;
constexpr uint32_t SGIP_REPORT_RESP = 0x80000005;
constexpr uint32_t SGIP_ADDSP = 0x00000006;
constexpr uint32_t SGIP_ADDSP_RESP = 0x80000006;
constexpr uint32_t SGIP_MODIFYSP = 0x00000007;
constexpr uint32_t SGIP_MODIFYSP_RESP = 0x80000007;
constexpr uint32_t SGIP_DELETESP = 0x00000008;
constexpr uint32_t SGIP_DELETESP_RESP = 0x80000008;
constexpr uint32_t SGIP_QUERYROUTE = 0x00000009;
constexpr uint32_t SGIP_QUERYROUTE_RESP = 0x80000009;
constexpr uint32_t SGIP_ADDTELESEG = 0x0000000A;
constexpr uint32_t SGIP_ADDTELESEG_RESP = 0x8000000A;
constexpr uint32_t SGIP_MODIFYTELESEG = 0x0000000B;
constexpr uint32_t SGIP_MODIFYTELESEG_RESP = 0x8000000B;
constexpr uint32_t SGIP_DELETETELESEG = 0x0000000C;
constexpr uint32_t SGIP_DELETETELESEG_RESP = 0x8000000C;
constexpr uint32_t SGIP_ADDSMG = 0x0000000D;
constexpr uint32_t SGIP_ADDSMG_RESP = 0x8000000D;
constexpr uint32_t SGIP_MODIFYSMG = 0x0000000E;
constexpr uint32_t SGIP_MODIFYSMG_RESP = 0x8000000E;
constexpr uint32_t SGIP_DELETESMG = 0x0000000F;
constexpr uint32_t SGIP_DELETESMG_RESP = 0x8000000F;
constexpr uint32_t SGIP_CHECKUSER = 0x00000010;
constexpr uint32_t SGIP_CHECKUSER_RESP = 0x80000010;
constexpr uint32_t SGIP_USERRPT = 0x00000011;
constexpr uint32_t SGIP_USERRPT_RESP = 0x80000011;
constexpr uint32_t SGIP_TRACE = 0x00001000;
constexpr uint32_t SGIP_TRACE_RESP = 0x80001000;

struct Header {
    uint32_t total_length;
    uint32_t command_id;
    uint64_t sequence_number;
};

struct Bind {
    char login_type;
    char login_name[16];
    char login_passwd[16];
    char reserve[8];
};

struct BindResp {
    char result;
    char reserve[8];
};

struct Pdu {
    Header header;
    union {
        Bind bind;
        BindResp bind_resp;
    };
};

size_t lengthBind();
std::vector<uint8_t> encodePdu(const Pdu& pdu);
Pdu decodePdu(const std::vector<uint8_t>& buffer);

#endif //PROTOCOL_H

内容

#include "sgipcpp/Protocol.h"
#include <cstring>
#include <ostream>
#include <stdexcept>
#include <sys/_endian.h>

size_t lengthBind(const Bind& bind) {
    return 1 + 16 + 16 + 8;
}

void encodeBind(const Bind& bind, std::vector<uint8_t>& buffer) {
    size_t offset = 16;

    buffer[offset++] = bind.login_type;
    std::memcpy(buffer.data() + offset, bind.login_name, 16);
    offset += 16;
    std::memcpy(buffer.data() + offset, bind.login_passwd, 16);
    offset += 16;
    std::memcpy(buffer.data() + offset, bind.reserve, 8);
}

BindResp decodeBindResp(const std::vector<uint8_t>& buffer) {
    BindResp bindResp;

    size_t offset = 0;

    offset += sizeof(uint32_t);
    offset += sizeof(uint32_t);

    bindResp.result = buffer[offset++];
    std::memcpy(bindResp.reserve, buffer.data() + offset, sizeof(bindResp.reserve));

    return bindResp;
}

std::vector<uint8_t> encodePdu(const Pdu& pdu) {
    size_t body_length;
    switch (pdu.header.command_id) {
        case SGIP_BIND:
            body_length = lengthBind(pdu.bind);
            break;
        default:
            throw std::runtime_error("Unsupported command ID for encoding");
    }

    std::vector<uint8_t> buffer(body_length + 16);
    uint32_t total_length = htonl(body_length + 16);
    std::memcpy(buffer.data(), &total_length, 4);

    uint32_t command_id = htonl(pdu.header.command_id);
    std::memcpy(buffer.data() + 4, &command_id, 4);

    uint32_t sequence_number = htonl(pdu.header.sequence_number);
    std::memcpy(buffer.data() + 8, &sequence_number, 8);

    switch (pdu.header.command_id) {
        case SGIP_BIND:
            encodeBind(pdu.bind, buffer);
        break;
        default:
            throw std::runtime_error("Unsupported command ID for encoding");
    }

    return buffer;
}

Pdu decodePdu(const std::vector<uint8_t>& buffer) {
    Pdu pdu;

    uint32_t command_id;
    std::memcpy(&command_id, buffer.data(), 4);
    pdu.header.command_id = ntohl(command_id);

    uint64_t sequence_number;
    std::memcpy(&sequence_number, buffer.data() + 8, 8);
    pdu.header.sequence_number = ntohl(sequence_number);

    switch (pdu.header.command_id) {
        case SGIP_BIND_RESP:
            pdu.bind_resp = decodeBindResp(buffer);
            break;
        default:
            throw std::runtime_error("Unsupported command ID for decoding");
    }

    return pdu;
}

实现客户端和登录方法

在**Client**中实现客户端和登录方法：

头文件

#ifndef CLIENT_H
#define CLIENT_H

#include "BoundAtomic.h"
#include "Protocol.h"
#include "asio.hpp"
#include <string>

class Client {
public:
    Client(const std::string& host, uint16_t port);
    ~Client();

    void connect();
    BindResp bind(const Bind& bind_request);
    void close();

private:
    std::string host_;
    uint16_t port_;
    asio::io_context io_context_;
    asio::ip::tcp::socket socket_;
    BoundAtomic* sequence_number_;

    void send(const std::vector<uint8_t>& data);
    std::vector<uint8_t> receive(size_t length);
};

#endif //CLIENT_H

内容

#include "sgipcpp/Client.h"
#include <iostream>

Client::Client(const std::string& host, uint16_t port)
    : host_(host), port_(port), socket_(io_context_) {
    sequence_number_ = new BoundAtomic(1, 0x7FFFFFFF);
}

Client::~Client() {
    close();
    delete sequence_number_;
}

void Client::connect() {
    asio::ip::tcp::resolver resolver(io_context_);
    asio::connect(socket_, resolver.resolve(host_, std::to_string(port_)));
}

BindResp Client::bind(const Bind& bind_request) {
    Pdu pdu;
    pdu.header.total_length = sizeof(Bind) + sizeof(Header);
    pdu.header.command_id = SGIP_BIND;
    pdu.header.sequence_number = sequence_number_->next_val();
    pdu.bind = bind_request;

    send(encodePdu(pdu));

    auto length_data = receive(4);
    uint32_t total_length = ntohl(*reinterpret_cast<uint32_t*>(length_data.data()));

    auto resp_data = receive(total_length - 4);
    Pdu resp_pdu = decodePdu(resp_data);
    return resp_pdu.bind_resp;
}

void Client::close() {
    socket_.close();
}

void Client::send(const std::vector<uint8_t>& data) {
    asio::write(socket_, asio::buffer(data));
}

std::vector<uint8_t> Client::receive(size_t length) {
    std::vector<uint8_t> buffer(length);
    asio::read(socket_, asio::buffer(buffer));
    return buffer;
}

运行example，验证连接成功

#include "sgipcpp/Client.h"
#include <iostream>

int main() {
    try {
        Client client("127.0.0.1", 8801);

        client.connect();
        std::cout << "Connected to the server." << std::endl;

        Bind bindRequest;
        bindRequest.login_type = 1;
        std::string login_name = "1234567890123456";
        std::string login_password = "1234567890123456";
        std::string reserve = "12345678";
        std::copy(login_name.begin(), login_name.end(), bindRequest.login_name);
        std::copy(login_password.begin(), login_password.end(), bindRequest.login_passwd);
        std::copy(reserve.begin(), reserve.end(), bindRequest.reserve);

        BindResp response = client.bind(bindRequest);
        if (response.result == 0) {
            std::cout << "Login successful." << std::endl;
        } else {
            std::cout << "Login failed with result code: " << static_cast<int>(response.result) << std::endl;
        }

        client.close();
        std::cout << "Connection closed." << std::endl;

    } catch (const std::exception& e) {
        std::cerr << "Error: " << e.what() << std::endl;
    }

    return 0;
}

相关开源项目

• netty-codec-sms 存放各种SMS协议（如cmpp、sgip、smpp）的netty编解码器
• sms-client-java 存放各种SMS协议的Java客户端
• sms-server-java 存放各种SMS协议的Java服务端
• cmpp-python cmpp协议的python实现
• cngp-zig cmpp协议的python实现
• sgip-cpp sgip协议的cpp实现
• smgp-perl smgp协议的perl实现
• smpp-rust smpp协议的rust实现

总结

本文简单对SGIP协议进行了介绍，并尝试用C++实现协议栈，但实际商用发送短信往往更加复杂，面临诸如流控、运营商对接、传输层安全等问题，可以选择华为云消息&短信（Message & SMS）服务通过HTTP协议接入，华为云短信服务是华为云携手全球多家优质运营商和渠道，为企业用户提供的通信服务。企业调用API或使用群发助手，即可使用验证码、通知短信服务。

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