public async Task <Response> TrackSucessRedirectionAsync(LinkTrackingRequest request)
{
try
{
using var conn = DbConnection;
var lt = new LinkTracking
{
Id = Guid.NewGuid(),
IpAddress = request.IpAddress,
LinkId = request.LinkId,
RequestTimeUtc = DateTime.UtcNow,
UserAgent = request.UserAgent
};
const string sqlInsertLt = @"INSERT INTO LinkTracking (Id, IpAddress, LinkId, RequestTimeUtc, UserAgent)
VALUES (@Id, @IpAddress, @LinkId, @RequestTimeUtc, @UserAgent)";
await conn.ExecuteAsync(sqlInsertLt, lt);
return(new SuccessResponse());
}
catch (Exception e)
{
_logger.LogError(e, e.Message);
return(new FailedResponse(e.Message));
}
}
public Task TrackSucessRedirectionAsync(LinkTrackingRequest request)
{
var lt = new LinkTracking
{
IpAddress = request.IpAddress,
LinkId = request.LinkId,
RequestTimeUtc = DateTime.UtcNow,
UserAgent = request.UserAgent
};
return(_connection.InsertAsync(lt));
}
private async Task <IActionResult> PerformTokenRedirection(string token, string ip)
{
var isValid = _tokenGenerator.TryParseToken(token, out var validatedToken);
if (!isValid)
{
return(BadRequest());
}
if (!_cache.TryGetValue(token, out Link linkEntry))
{
var flag = await _featureManager.IsEnabledAsync(nameof(FeatureFlags.AllowSelfRedirection));
var link = await _linkForwarderService.GetLinkAsync(validatedToken);
if (link is null)
{
if (string.IsNullOrWhiteSpace(_appSettings.DefaultRedirectionUrl))
{
return(NotFound());
}
var result = _linkVerifier.Verify(_appSettings.DefaultRedirectionUrl, Url, Request, flag);
if (result == LinkVerifyResult.Valid)
{
return(Redirect(_appSettings.DefaultRedirectionUrl));
}
throw new UriFormatException("DefaultRedirectionUrl is not a valid URL.");
}
if (!link.IsEnabled)
{
return(BadRequest("This link is disabled."));
}
var verifyOriginUrl = _linkVerifier.Verify(link.OriginUrl, Url, Request, flag);
switch (verifyOriginUrl)
{
case LinkVerifyResult.Valid:
// cache valid link entity only.
if (link.TTL is not null)
{
_cache.Set(token, link, TimeSpan.FromSeconds(link.TTL.GetValueOrDefault()));
}
break;
case LinkVerifyResult.InvalidFormat:
throw new UriFormatException(
$"OriginUrl '{link.OriginUrl}' is not a valid URL, link ID: {link.Id}.");
case LinkVerifyResult.InvalidLocal:
_logger.LogWarning($"Local redirection is blocked. link: {JsonSerializer.Serialize(link)}");
return(BadRequest("Local redirection is blocked"));
case LinkVerifyResult.InvalidSelfReference:
_logger.LogWarning(
$"Self reference redirection is blocked. link: {JsonSerializer.Serialize(link)}");
return(BadRequest("Self reference redirection is blocked"));
default:
throw new ArgumentOutOfRangeException();
}
}
linkEntry ??= _cache.Get <Link>(token);
var honorDNTFlag = await _featureManager.IsEnabledAsync(nameof(FeatureFlags.HonorDNT));
if (!honorDNTFlag)
{
return(Redirect(linkEntry.OriginUrl));
}
// Check if browser sends "Do Not Track"
var dntFlag = Request.Headers["DNT"];
var dnt = !string.IsNullOrWhiteSpace(dntFlag) && dntFlag == "1";
if (dnt)
{
return(Redirect(linkEntry.OriginUrl));
}
try
{
var req = new LinkTrackingRequest(ip, UserAgent, linkEntry.Id);
await _linkForwarderService.TrackSucessRedirectionAsync(req);
}
catch (Exception e)
{
// Eat exception, pretend everything is fine
// Do not block workflow here
_logger.LogError(e.Message, e);
}
return(Redirect(linkEntry.OriginUrl));
}
