SIPSorcery通讯实例

【实例简介】

本实例采用SIPSorcery插件实现GB2818监控视频播放等功能，重点介绍SIP协议对报文的处理。

【实例截图】

【核心代码】

using System;
using System.Collections.Generic;
using System.Net;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.Extensions.Logging;
using Serilog;
using Serilog.Sinks.SystemConsole.Themes;
using SIPSorcery.SIP;
using SIPSorcery.SIP.App;

namespace SIPSorcery.SIPProxy
{
    struct SIPAccountBinding
    {
        public SIPAccount SIPAccount;
        public SIPURI RegisteredContact;
        public SIPEndPoint RemoteEndPoint;
        public SIPEndPoint LocalEndPoint;
        public int Expiry;

        public SIPAccountBinding(SIPAccount sipAccount, SIPURI contact, SIPEndPoint remote, SIPEndPoint local, int expiry)
        {
            SIPAccount = sipAccount;
            RegisteredContact = contact;
            RemoteEndPoint = remote;
            LocalEndPoint = local;
            Expiry = expiry;
        }
    }

    class Program
    {
        private static int _listenPort = SIPConstants.DEFAULT_SIP_PORT;             // The default UDP SIP port.

        private static Microsoft.Extensions.Logging.ILogger logger = SIPSorcery.Sys.Log.Logger;

        private static SIPTransport _sipTransport;
        private static Dictionary<string, SIPAccountBinding> _sipRegistrations = new Dictionary<string, SIPAccountBinding>(); // [SIP Username, Binding], tracks SIP clients that have registered with the server.

        static void Main()
        {
            try
            {
                Console.WriteLine("SIPSorcery SIP Proxy Demo");

                AddConsoleLogger();

                // Configure the SIP transport layer.
                _sipTransport = new SIPTransport();

                // Use default options to set up a SIP channel.
                var sipChannel = new SIPUDPChannel(new IPEndPoint(IPAddress.Any, _listenPort));
                _sipTransport.AddSIPChannel(sipChannel);

                var ipv6SipChannel = new SIPUDPChannel(new IPEndPoint(IPAddress.IPv6Any, _listenPort));
                _sipTransport.AddSIPChannel(ipv6SipChannel);

                // Wire up the transport layer so SIP requests and responses have somewhere to go.
                _sipTransport.SIPTransportRequestReceived = SIPTransportRequestReceived;
                _sipTransport.SIPTransportResponseReceived = SIPTransportResponseReceived;

                // If you want to see ALL the nitty gritty SIP traffic wire up the events below.
                //_sipTransport.SIPBadRequestInTraceEvent = SIPBadRequestInTraceEvent;
                //_sipTransport.SIPBadResponseInTraceEvent = SIPBadResponseInTraceEvent;
                _sipTransport.SIPRequestInTraceEvent = SIPRequestInTraceEvent;
                //_sipTransport.SIPRequestOutTraceEvent = SIPRequestOutTraceEvent;
                //_sipTransport.SIPResponseInTraceEvent = SIPResponseInTraceEvent;
                _sipTransport.SIPResponseOutTraceEvent = SIPResponseOutTraceEvent;

                ManualResetEvent mre = new ManualResetEvent(false);
                mre.WaitOne();
            }
            catch (Exception excp)
            {
                Console.WriteLine("Exception Main. " excp);
            }
        }

        /// <summary>
        /// Handler for processing incoming SIP requests.
        /// </summary>
        /// <param name="localSIPEndPoint">The end point the request was received on.</param>
        /// <param name="remoteEndPoint">The end point the request came from.</param>
        /// <param name="sipRequest">The SIP request received.</param>
        private static async Task SIPTransportRequestReceived(SIPEndPoint localSIPEndPoint, SIPEndPoint remoteEndPoint, SIPRequest sipRequest)
        {
            try
            {
                if (sipRequest.Method == SIPMethodsEnum.BYE)
                {
                    throw new NotImplementedException();
                }
                else if (sipRequest.Method == SIPMethodsEnum.CANCEL)
                {
                    throw new NotImplementedException();
                }
                else if (sipRequest.Method == SIPMethodsEnum.INVITE)
                {
                    throw new NotImplementedException();
                }
                else if (sipRequest.Method == SIPMethodsEnum.OPTIONS)
                {
                    SIPResponse optionsResponse = SIPResponse.GetResponse(sipRequest, SIPResponseStatusCodesEnum.Ok, null);
                    await _sipTransport.SendResponseAsync(optionsResponse);
                }
                else if (sipRequest.Method == SIPMethodsEnum.REGISTER)
                {
                    SIPResponse tryingResponse = SIPResponse.GetResponse(sipRequest, SIPResponseStatusCodesEnum.Trying, null);
                    await _sipTransport.SendResponseAsync(tryingResponse);

                    SIPResponseStatusCodesEnum registerResponse = SIPResponseStatusCodesEnum.Ok;

                    if (sipRequest.Header.Contact != null && sipRequest.Header.Contact.Count > 0)
                    {
                        int expiry = sipRequest.Header.Contact[0].Expires > 0 ? sipRequest.Header.Contact[0].Expires : sipRequest.Header.Expires;
                        var sipAccount = new SIPAccount(null, sipRequest.Header.From.FromURI.Host, sipRequest.Header.From.FromURI.User, null, null);
                        SIPAccountBinding binding = new SIPAccountBinding(sipAccount, sipRequest.Header.Contact[0].ContactURI, remoteEndPoint, localSIPEndPoint, expiry);

                        if (_sipRegistrations.ContainsKey(sipAccount.SIPUsername))
                        {
                            _sipRegistrations.Remove(sipAccount.SIPUsername);
                        }

                        _sipRegistrations.Add(sipAccount.SIPUsername, binding);

                        logger.LogDebug("Registered contact for " sipAccount.SIPUsername " as " binding.RegisteredContact.ToString() ".");
                    }
                    else
                    {
                        registerResponse = SIPResponseStatusCodesEnum.BadRequest;
                    }

                    SIPNonInviteTransaction registerTransaction = new SIPNonInviteTransaction(_sipTransport, sipRequest, null);
                    SIPResponse okResponse = SIPResponse.GetResponse(sipRequest, registerResponse, null);
                    registerTransaction.SendResponse(okResponse);
                }
                else
                {
                    logger.LogDebug("SIP " sipRequest.Method " request received but no processing has been set up for it, rejecting.");
                }
            }
            catch (NotImplementedException)
            {
                logger.LogDebug(sipRequest.Method " request processing not implemented for " sipRequest.URI.ToParameterlessString() " from " remoteEndPoint ".");

                SIPResponse notImplResponse = SIPResponse.GetResponse(sipRequest, SIPResponseStatusCodesEnum.NotImplemented, null);
                await _sipTransport.SendResponseAsync(notImplResponse);
            }
        }

        /// <summary>
        /// Handler for processing incoming SIP responses.
        /// </summary>
        /// <param name="localSIPEndPoint">The end point the response was received on.</param>
        /// <param name="remoteEndPoint">The end point the response came from.</param>
        /// <param name="sipResponse">The SIP response received.</param>
        private static Task SIPTransportResponseReceived(SIPEndPoint localSIPEndPoint, SIPEndPoint remoteEndPoint, SIPResponse sipResponse)
        {
            logger.LogDebug("Response received from " remoteEndPoint " method " sipResponse.Header.CSeqMethod " status " sipResponse.Status ".");
            return Task.CompletedTask;
        }

        #region Non-functional trace/logging handlers. Main use is troubleshooting.

        /// <summary>
        ///  Adds a console logger. Can be omitted if internal SIPSorcery debug and warning messages are not required.
        /// </summary>
        private static void AddConsoleLogger()
        {
            var loggerFactory = new Microsoft.Extensions.Logging.LoggerFactory();
            var loggerConfig = new LoggerConfiguration()
                .WriteTo.Console(theme: AnsiConsoleTheme.Code)
                .Enrich.FromLogContext()
                .MinimumLevel.Is(Serilog.Events.LogEventLevel.Debug)
                .WriteTo.Console()
                .CreateLogger();
            loggerFactory.AddSerilog(loggerConfig);
            SIPSorcery.Sys.Log.LoggerFactory = loggerFactory;
        }

        private static void SIPRequestInTraceEvent(SIPEndPoint localSIPEndPoint, SIPEndPoint remoteEndPoint, SIPRequest sipRequest)
        {
            logger.LogDebug("REQUEST IN {0}->{1}: {2}", remoteEndPoint.ToString(), localSIPEndPoint.ToString(), sipRequest.StatusLine);
            //logger.LogDebug(sipRequest.ToString());
        }

        private static void SIPRequestOutTraceEvent(SIPEndPoint localSIPEndPoint, SIPEndPoint remoteEndPoint, SIPRequest sipRequest)
        {
            logger.LogDebug("REQUEST OUT {0}->{1}: {2}", localSIPEndPoint.ToString(), remoteEndPoint.ToString(), sipRequest.StatusLine);
            //logger.LogDebug(sipRequest.ToString());
        }

        private static void SIPResponseInTraceEvent(SIPEndPoint localSIPEndPoint, SIPEndPoint remoteEndPoint, SIPResponse sipResponse)
        {
            logger.LogDebug("RESPONSE IN {0}->{1}: {2}", remoteEndPoint.ToString(), localSIPEndPoint.ToString(), sipResponse.ShortDescription);
            //logger.LogDebug(sipResponse.ToString());
        }

        private static void SIPResponseOutTraceEvent(SIPEndPoint localSIPEndPoint, SIPEndPoint remoteEndPoint, SIPResponse sipResponse)
        {
            logger.LogDebug("RESPONSE OUT {0}->{1}: {2}", localSIPEndPoint.ToString(), remoteEndPoint.ToString(), sipResponse.ShortDescription);
            //logger.LogDebug(sipResponse.ToString());
        }

        private static void SIPBadRequestInTraceEvent(SIPEndPoint localSIPEndPoint, SIPEndPoint remoteEndPoint, string message, SIPValidationFieldsEnum sipErrorField, string rawMessage)
        {
            logger.LogWarning("Bad SIPRequest. Field=" sipErrorField ", Message=" message ", Remote=" remoteEndPoint.ToString() ".");
        }

        private static void SIPBadResponseInTraceEvent(SIPEndPoint localSIPEndPoint, SIPEndPoint remoteEndPoint, string message, SIPValidationFieldsEnum sipErrorField, string rawMessage)
        {
            logger.LogWarning("Bad SIPResponse. Field=" sipErrorField ", Message=" message ", Remote=" remoteEndPoint.ToString() ".");
        }

        #endregion
    }
}