Send SMS with SMPP using Go

main.go

package main

import (
	"fmt"
	"log"
	"strings"
	"sync"
	"time"

	"github.com/linxGnu/gosmpp"
	"github.com/linxGnu/gosmpp/data"
	"github.com/linxGnu/gosmpp/pdu"
)

func main() {
	var wg sync.WaitGroup

	wg.Add(1)
	go sendingAndReceiveSMS(&wg)

	wg.Wait()
}

func sendingAndReceiveSMS(wg *sync.WaitGroup) {
	defer wg.Done()

	auth := gosmpp.Auth{
		SMSC:       "smscsim.smpp.org:2775",
		SystemID:   "SYSTEMID",
		Password:   "PASSWORD",
		SystemType: "",
	}

	trans, err := gosmpp.NewSession(
		gosmpp.TRXConnector(gosmpp.NonTLSDialer, auth),
		gosmpp.Settings{
			EnquireLink: 5 * time.Second,

			ReadTimeout: 10 * time.Second,

			OnSubmitError: func(_ pdu.PDU, err error) {
				log.Fatal("SubmitPDU error:", err)
			},

			OnReceivingError: func(err error) {
				fmt.Println("Receiving PDU/Network error:", err)
			},

			OnRebindingError: func(err error) {
				fmt.Println("Rebinding but error:", err)
			},

			OnPDU: handlePDU(),

			OnClosed: func(state gosmpp.State) {
				fmt.Println(state)
			},
		}, 5*time.Second)
	if err != nil {
		log.Fatal(err)
	}
	defer func() {
		_ = trans.Close()
	}()

	// sending SMS(s)
	for i := 0; i < 1; i++ {
		if err = trans.Transceiver().Submit(newSubmitSM()); err != nil {
			fmt.Println(err)
		}
		time.Sleep(5*time.Second)
	}
}

func handlePDU() func(pdu.PDU, bool) {
	concatenated := map[uint8][]string{}
	return func(p pdu.PDU, _ bool) {
		switch pd := p.(type) {
		case *pdu.SubmitSMResp:
			fmt.Printf("SubmitSMResp:%+v\n", pd)

		case *pdu.GenericNack:
			fmt.Println("GenericNack Received")

		case *pdu.EnquireLinkResp:
			fmt.Println("EnquireLinkResp Received")

		case *pdu.DataSM:
			fmt.Printf("DataSM:%+v\n", pd)

		case *pdu.DeliverSM:
			fmt.Printf("DeliverSM:%+v\n", pd)
			log.Println(pd.Message.GetMessage())
			// region concatenated sms (sample code)
			message, err := pd.Message.GetMessage()
			if err != nil {
				log.Fatal(err)
			}
			totalParts, sequence, reference, found := pd.Message.UDH().GetConcatInfo()
			if found {
				if _, ok := concatenated[reference]; !ok {
					concatenated[reference] = make([]string, totalParts)
				}
				concatenated[reference][sequence-1] = message
			}
			if !found {
				log.Println(message)
			} else if parts, ok := concatenated[reference]; ok && isConcatenatedDone(parts, totalParts) {
				log.Println(strings.Join(parts, ""))
				delete(concatenated, reference)
			}
			// endregion
		}
	}
}

func newSubmitSM() *pdu.SubmitSM {
	// build up submitSM
	srcAddr := pdu.NewAddress()
	srcAddr.SetTon(5)
	srcAddr.SetNpi(0)
	_ = srcAddr.SetAddress("MelroseLabs")

	destAddr := pdu.NewAddress()
	destAddr.SetTon(1)
	destAddr.SetNpi(1)
	_ = destAddr.SetAddress("447712345678")

	submitSM := pdu.NewSubmitSM().(*pdu.SubmitSM)
	submitSM.SourceAddr = srcAddr
	submitSM.DestAddr = destAddr
	_ = submitSM.Message.SetMessageWithEncoding("Hello World €$£", data.UCS2)
	submitSM.ProtocolID = 0
	submitSM.RegisteredDelivery = 1
	submitSM.ReplaceIfPresentFlag = 0
	submitSM.EsmClass = 0

	return submitSM
}

func isConcatenatedDone(parts []string, total byte) bool {
	for _, part := range parts {
		if part != "" {
			total--
		}
	}
	return total == 0
}

go.mod

module example

go 1.17

require github.com/linxGnu/gosmpp v0.1.6

require golang.org/x/text v0.7.0 // indirect

% go run main.go
SubmitSMResp:&{base:{Header:{CommandLength:53 CommandID:SUBMIT_SM_RESP CommandStatus:ESME_ROK SequenceNumber:3} OptionalParameters:map[]} MessageID:1f1ced792041033a07f15c76aa5a7d4ff8b9}
DeliverSM:&{base:{Header:{CommandLength:238 CommandID:DELIVER_SM CommandStatus:ESME_ROK SequenceNumber:1} OptionalParameters:map[30:{Tag:30 Data:[49 102 49 99 101 100 55 57 50 48 52 49 48 51 51 97 48 55 102 49 53 99 55 54 97 97 53 97 55 100 52 102 102 56 98 57 0]} 1059:{Tag:1059 Data:[3 0 0]} 1063:{Tag:1063 Data:[2]}]} ServiceType: SourceAddr:447712345678 DestAddr:MelroseLabs EsmClass:4 ProtocolID:0 PriorityFlag:0 ScheduleDeliveryTime: ValidityPeriod: RegisteredDelivery:0 ReplaceIfPresentFlag:0 Message:{SmDefaultMsgID:0 message: enc:0x1050bafa0 udHeader:[] messageData:[105 100 58 49 102 49 99 101 100 55 57 50 48 52 49 48 51 51 97 48 55 102 49 53 99 55 54 97 97 53 97 55 100 52 102 102 56 98 57 32 115 117 98 58 48 48 48 32 100 108 118 114 100 58 48 48 49 32 115 117 98 109 105 116 32 100 97 116 101 58 50 51 48 50 50 49 49 55 53 54 32 100 111 110 101 32 100 97 116 101 58 50 51 48 50 50 49 49 55 53 54 32 115 116 97 116 58 68 69 76 73 86 82 68 32 101 114 114 58 48 48 48 32 116 101 120 116 58 0] withoutDataCoding:false}}
2023/02/21 17:56:22 id:1f1ced792041033a07f15c76aa5a7d4ff8b9 sub:000 dlvrd:001 submit date:2302211756 done date:2302211756 stat:DELIVRD err:000 text:@ 
2023/02/21 17:56:22 id:1f1ced792041033a07f15c76aa5a7d4ff8b9 sub:000 dlvrd:001 submit date:2302211756 done date:2302211756 stat:DELIVRD err:000 text:@