本文分享自华为云社区《华为云短信服务教你用Rust实现Smpp协议》,作者: 张俭。
协议概述
SMPP(Short Message Peer-to-Peer)协议起源于90年代,最初由Aldiscon公司开发,后来由SMPP开发者论坛维护和推广。SMPP常用于在SMSC(Short Message Service Center,短信中心)和短信应用之间传输短消息,支持高效的短信息发送、接收和查询功能,是电信运营商和短信服务提供商之间互通短信的主要协议之一。
SMPP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SMSC建立起TCP长连接,并使用SMPP命令与SMSC进行交互,实现短信的发送和接收。在SMPP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
绑定transmitter模式,发送短信并查询短信发送成功
![](http://www.e-1.cn/wp-content/uploads/2024/02/frc-3642f0eab1adfc810a376937c5f00b1a.png)
绑定receiver模式,从SMSC接收到短信
![](http://www.e-1.cn/wp-content/uploads/2024/02/frc-91f83ffb7cc052ceef5a0c0a29ab67a1.png)
协议帧介绍
在SMPP协议中,每个PDU都包含两个部分:SMPP Header和SMPP Body。
SMPP Header
Header包含以下字段,大小长度都是4字节:
- Command Length:整个PDU的长度,包括Header和Body。
- Command ID:用于标识PDU的类型(例如,BindReceiver、QuerySM等)。
- Command Status:响应状态码,表示处理的结果。
- Sequence Number:序列号,用来匹配请求和响应。
用Rust实现SMPP协议栈里的BindTransmitter
本文的代码均已上传到smpp-rust
选用Tokio作为基础的异步运行时环境,tokio有非常强大的异步IO支持,也是rust库的事实标准。
代码结构组织如下:
├── lib.rs ├── const.rs ├── protocol.rs ├── smpp_client.rs └── smpp_server.rs
- lib.rs Rust项目的入口点
- const.rs 包含常量定义,如commandId、状态码等
- protocol.rs 包含PDU定义,编解码处理等
- smpp_client.rs 实现smpp客户端逻辑
- smpp_server.rs 实现
利用rust原子类实现sequence_number
sequence_number是从1到0x7FFFFFFF的值,利用Rust的AtomicI32来生成这个值。
use std::sync::atomic::{AtomicI32, Ordering}; use std::num::TryFromIntError; struct BoundAtomicInt { min: i32, max: i32, integer: AtomicI32, } impl BoundAtomicInt { pub fn new(min: i32, max: i32) -> Self { assert!(min Result { let next = self.integer.fetch_update(Ordering::SeqCst, Ordering::SeqCst, |x| { Some(if x >= self.max { self.min } else { x + 1 }) })?; Ok(next) } }
在Rust中定义SMPP PDU
pub struct SmppPdu { pub header: SmppHeader, pub body: SmppBody, } pub struct SmppHeader { pub command_length: i32, pub command_id: i32, pub command_status: i32, pub sequence_number: i32, } pub enum SmppBody { BindReceiver(BindReceiver), BindReceiverResp(BindReceiverResp), BindTransmitter(BindTransmitter), BindTransmitterResp(BindTransmitterResp), QuerySm(QuerySm), QuerySmResp(QuerySmResp), SubmitSm(SubmitSm), SubmitSmResp(SubmitSmResp), DeliverSm(DeliverSm), DeliverSmResp(DeliverSmResp), Unbind(Unbind), UnbindResp(UnbindResp), ReplaceSm(ReplaceSm), ReplaceSmResp(ReplaceSmResp), CancelSm(CancelSm), CancelSmResp(CancelSmResp), BindTransceiver(BindTransceiver), BindTransceiverResp(BindTransceiverResp), Outbind(Outbind), EnquireLink(EnquireLink), EnquireLinkResp(EnquireLinkResp), SubmitMulti(SubmitMulti), SubmitMultiResp(SubmitMultiResp), }
实现编解码方法
impl SmppPdu { pub fn encode(&self) -> Vec { let mut body_buf = match &self.body { SmppBody::BindTransmitter(bind_transmitter) => bind_transmitter.encode(), _ => unimplemented!(), }; let command_length = (body_buf.len() + 16) as i32; let header = SmppHeader { command_length, command_id: self.header.command_id, command_status: self.header.command_status, sequence_number: self.header.sequence_number, }; let mut buf = header.encode(); buf.append(&mut body_buf); buf } pub fn decode(buf: &[u8]) -> io::Result { let header = SmppHeader::decode(&buf[0..16])?; let body = match header.command_id { constant::BIND_TRANSMITTER_RESP_ID => SmppBody::BindTransmitterResp(BindTransmitterResp::decode(&buf[16..])?), _ => unimplemented!(), }; Ok(SmppPdu { header, body }) } } impl SmppHeader { pub(crate) fn encode(&self) -> Vec { let mut buf = vec![]; buf.extend_from_slice(&self.command_length.to_be_bytes()); buf.extend_from_slice(&self.command_id.to_be_bytes()); buf.extend_from_slice(&self.command_status.to_be_bytes()); buf.extend_from_slice(&self.sequence_number.to_be_bytes()); buf } pub(crate) fn decode(buf: &[u8]) -> io::Result { if buf.len() Vec { let mut buf = vec![]; write_cstring(&mut buf, &self.system_id); write_cstring(&mut buf, &self.password); write_cstring(&mut buf, &self.system_type); buf.push(self.interface_version); buf.push(self.addr_ton); buf.push(self.addr_npi); write_cstring(&mut buf, &self.address_range); buf } pub(crate) fn decode(buf: &[u8]) -> io::Result { let mut offset = 0; let system_id = read_cstring(buf, &mut offset)?; let password = read_cstring(buf, &mut offset)?; let system_type = read_cstring(buf, &mut offset)?; let interface_version = buf[offset]; offset += 1; let addr_ton = buf[offset]; offset += 1; let addr_npi = buf[offset]; offset += 1; let address_range = read_cstring(buf, &mut offset)?; Ok(BindTransmitter { system_id, password, system_type, interface_version, addr_ton, addr_npi, address_range, }) } }
实现同步的bind_transmitter方法
pub async fn bind_transmitter( &mut self, bind_transmitter: BindTransmitter, ) -> io::Result { if let Some(stream) = &mut self.stream { let sequence_number = self.sequence_number.next_val(); let pdu = SmppPdu { header: SmppHeader { command_length: 0, command_id: constant::BIND_TRANSMITTER_ID, command_status: 0, sequence_number, }, body: SmppBody::BindTransmitter(bind_transmitter), }; let encoded_request = pdu.encode(); stream.write_all(&encoded_request).await?; let mut length_buf = [0u8; 4]; stream.read_exact(&mut length_buf).await?; let msg_length = u32::from_be_bytes(length_buf) as usize - 4; let mut msg_buf = vec![0u8; msg_length]; stream.read_exact(&mut msg_buf).await?; let response = SmppPdu::decode(&msg_buf)?; if response.header.command_status != 0 { Err(io::Error::new( io::ErrorKind::Other, format!("Error response: {:?}", response.header.command_status), )) } else { // Assuming response.body is of type BindTransmitterResp match response.body { SmppBody::BindTransmitterResp(resp) => Ok(resp), _ => Err(io::Error::new(io::ErrorKind::InvalidData, "Unexpected response body")), } } } else { Err(io::Error::new(io::ErrorKind::NotConnected, "Not connected")) } }
运行example,验证连接成功
use smpp_rust::protocol::BindTransmitter; use smpp_rust::smpp_client::SmppClient; #[tokio::main] async fn main() -> Result> { let mut client = SmppClient::new("127.0.0.1", 2775); client.connect().await?; let bind_transmitter = BindTransmitter{ system_id: "system_id".to_string(), password: "password".to_string(), system_type: "system_type".to_string(), interface_version: 0x34, addr_ton: 0, addr_npi: 0, address_range: "".to_string(), }; client.bind_transmitter(bind_transmitter).await?; client.close().await?; Ok(()) }
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
- smpp-rust smpp协议的rust实现
总结
本文简单对SMPP协议进行了介绍,并尝试用rust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,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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