// Runner
public static async Task <IActionResult> Run(HttpRequest req, ILogger log, ExecutionContext context, ApiVersion currentApiVersion)
{
// set the current version in the response header
req.HttpContext.Response.Headers.Add(ApiVersion.HttpHeaderName, currentApiVersion.Version);
var requestedVersion = req.GetRequestedVersion();
if (requestedVersion == null || !currentApiVersion.SupportsVersion(requestedVersion))
{
return(new BadRequestObjectResult($"Incompatible versions (requested: '{requestedVersion.Name ?? string.Empty}', current: '{currentApiVersion.Name}')"));
}
//ABP Case
string devAddr = req.Query["DevAddr"];
//OTAA Case
string devEUI = req.Query["DevEUI"];
string devNonce = req.Query["DevNonce"];
string gatewayId = req.Query["GatewayId"];
if (redisCache == null || registryManager == null)
{
lock (typeof(FCntCacheCheck))
{
if (redisCache == null || registryManager == null)
{
var config = new ConfigurationBuilder()
.SetBasePath(context.FunctionAppDirectory)
.AddJsonFile("local.settings.json", optional: true, reloadOnChange: true)
.AddEnvironmentVariables()
.Build();
string connectionString = config.GetConnectionString("IoTHubConnectionString");
if (connectionString == null)
{
string errorMsg = "Missing IoTHubConnectionString in settings";
throw new Exception(errorMsg);
}
string redisConnectionString = config.GetConnectionString("RedisConnectionString");
if (redisConnectionString == null)
{
string errorMsg = "Missing RedisConnectionString in settings";
throw new Exception(errorMsg);
}
registryManager = RegistryManager.CreateFromConnectionString(connectionString);
var redis = ConnectionMultiplexer.Connect(redisConnectionString);
redisCache = redis.GetDatabase();
}
}
}
List <IoTHubDeviceInfo> results = new List <IoTHubDeviceInfo>();
//OTAA join
if (devEUI != null)
{
string cacheKey = devEUI + devNonce;
try
{
if (redisCache.LockTake(cacheKey + "joinlock", gatewayId, new TimeSpan(0, 0, 10)))
{
//check if we already got the same devEUI and devNonce it can be a reaply attack or a multigateway setup recieving the same join.We are rfusing all other than the first one.
string cachedDevNonce = redisCache.StringGet(cacheKey, CommandFlags.DemandMaster);
if (!String.IsNullOrEmpty(cachedDevNonce))
{
return((ActionResult) new BadRequestObjectResult("UsedDevNonce"));
}
redisCache.StringSet(cacheKey, devNonce, new TimeSpan(0, 1, 0), When.Always, CommandFlags.DemandMaster);
IoTHubDeviceInfo iotHubDeviceInfo = new IoTHubDeviceInfo();
var device = await registryManager.GetDeviceAsync(devEUI);
if (device != null)
{
iotHubDeviceInfo.DevEUI = devEUI;
iotHubDeviceInfo.PrimaryKey = device.Authentication.SymmetricKey.PrimaryKey;
results.Add(iotHubDeviceInfo);
//clear device FCnt cache after join
redisCache.KeyDelete(devEUI);
}
}
}
finally
{
redisCache.LockRelease(cacheKey + "joinlock", gatewayId);
}
}
//ABP or normal message
else if (devAddr != null)
{
//TODO check for sql injection
devAddr = devAddr.Replace('\'', ' ');
var query = registryManager.CreateQuery($"SELECT * FROM devices WHERE properties.desired.DevAddr = '{devAddr}' OR properties.reported.DevAddr ='{devAddr}'", 100);
while (query.HasMoreResults)
{
var page = await query.GetNextAsTwinAsync();
foreach (var twin in page)
{
if (twin.DeviceId != null)
{
IoTHubDeviceInfo iotHubDeviceInfo = new IoTHubDeviceInfo();
iotHubDeviceInfo.DevAddr = devAddr;
var device = await registryManager.GetDeviceAsync(twin.DeviceId);
iotHubDeviceInfo.DevEUI = twin.DeviceId;
iotHubDeviceInfo.PrimaryKey = device.Authentication.SymmetricKey.PrimaryKey;
results.Add(iotHubDeviceInfo);
}
}
}
}
else
{
string errorMsg = "Missing devEUI or devAddr";
throw new Exception(errorMsg);
}
string json = JsonConvert.SerializeObject(results);
return((ActionResult) new OkObjectResult(json));
}
public static IActionResult Run(HttpRequest req, ILogger log, ExecutionContext context, ApiVersion currentApiVersion)
{
// set the current version in the response header
req.HttpContext.Response.Headers.Add(ApiVersion.HttpHeaderName, currentApiVersion.Version);
var requestedVersion = req.GetRequestedVersion();
if (requestedVersion == null || !currentApiVersion.SupportsVersion(requestedVersion))
{
return(new BadRequestObjectResult($"Incompatible versions (requested: '{requestedVersion.Name ?? string.Empty}', current: '{currentApiVersion.Name}')"));
}
FCnt serverFCnt;
string devEUI = req.Query["DevEUI"];
string fCntDown = req.Query["FCntDown"];
string fCntUp = req.Query["FCntUp"];
string gatewayId = req.Query["GatewayId"];
string abpFcntCacheReset = req.Query["ABPFcntCacheReset"];
int newFCntDown = 0;
if (redisCache == null)
{
lock (typeof(FCntCacheCheck))
{
if (redisCache == null)
{
var config = new ConfigurationBuilder()
.SetBasePath(context.FunctionAppDirectory)
.AddJsonFile("local.settings.json", optional: true, reloadOnChange: true)
.AddEnvironmentVariables()
.Build();
var redisConnectionString = config.GetConnectionString("RedisConnectionString");
if (string.IsNullOrEmpty(redisConnectionString))
{
string errorMsg = "Missing RedisConnectionString in settings";
throw new Exception(errorMsg);
}
var redis = ConnectionMultiplexer.Connect(redisConnectionString);
redisCache = redis.GetDatabase();
}
}
}
if (!string.IsNullOrEmpty(abpFcntCacheReset))
{
redisCache.KeyDelete(devEUI);
return((ActionResult) new OkObjectResult(null));
}
if (!string.IsNullOrEmpty(devEUI) && !string.IsNullOrEmpty(fCntDown) && !string.IsNullOrEmpty(fCntUp) && !string.IsNullOrEmpty(gatewayId))
{
int clientFCntDown = int.Parse(fCntDown);
int clientFCntUp = int.Parse(fCntUp);
string cacheKey = devEUI;
try
{
if (redisCache.LockTake(cacheKey + "msglock", gatewayId, new TimeSpan(0, 0, 10)))
{
string cachedFCnt = redisCache.StringGet(cacheKey, CommandFlags.DemandMaster);
// we have it cached
if (!string.IsNullOrEmpty(cachedFCnt))
{
serverFCnt = (FCnt)JsonConvert.DeserializeObject(cachedFCnt, typeof(FCnt));
// it is a new message coming up by the first gateway
if (clientFCntUp > serverFCnt.FCntUp)
{
if (clientFCntDown >= serverFCnt.FCntDown)
{
newFCntDown = (int)(clientFCntDown + 1);
}
else
{
newFCntDown = (int)(serverFCnt.FCntDown + 1);
}
serverFCnt.FCntUp = clientFCntUp;
serverFCnt.FCntDown = newFCntDown;
serverFCnt.GatewayId = gatewayId;
CacheFcnt(serverFCnt, redisCache, cacheKey);
}
// it is a retry message coming up by the same first gateway
else if (clientFCntUp == serverFCnt.FCntUp && gatewayId == serverFCnt.GatewayId)
{
newFCntDown = serverFCnt.FCntDown + 1;
serverFCnt.FCntDown = newFCntDown;
CacheFcnt(serverFCnt, redisCache, cacheKey);
}
else
{
// we tell not to send any ack or downstream msg
newFCntDown = 0;
}
}
// it is the first message from this device
else
{
newFCntDown = clientFCntDown + 1;
serverFCnt = new FCnt();
serverFCnt.FCntDown = newFCntDown;
serverFCnt.FCntUp = clientFCntUp;
serverFCnt.GatewayId = gatewayId;
CacheFcnt(serverFCnt, redisCache, cacheKey);
}
}
}
finally
{
redisCache.LockRelease(cacheKey + "msglock", gatewayId);
}
}
else
{
string errorMsg = "Missing DevEUI or FCntDown or FCntUp or GatewayId";
throw new Exception(errorMsg);
}
return((ActionResult) new OkObjectResult(newFCntDown));
}
