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
![image.png]()
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;
}
![image.png]()
相关开源项目
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。
点击关注，第一时间了解华为云新鲜技术~
