jellyfin-jellyfin-1/Jellyfin.Api/Auth/NetworkAccessPolicy/NetworkAccessHandler.cs

using System.Threading.Tasks;
using Jellyfin.Api.Auth;
using MediaBrowser.Common.Extensions;
using MediaBrowser.Common.Net;
using MediaBrowser.Controller.Library;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Http;

namespace Jellyfin.Api.Auth.NetworkAccessPolicy
{
    /// <summary>
    /// Local access handler.
    /// </summary>
    public class NetworkAccessHandler : BaseAuthorizationHandler<NetworkAccessRequirement>
    {
        /// <summary>
        /// Initializes a new instance of the <see cref="NetworkAccessHandler"/> class.
        /// </summary>
        /// <param name="userManager">Instance of the <see cref="IUserManager"/> interface.</param>
        /// <param name="networkManager">Instance of the <see cref="INetworkManager"/> interface.</param>
        /// <param name="httpContextAccessor">Instance of the <see cref="IHttpContextAccessor"/> interface.</param>
        public NetworkAccessHandler(
            IUserManager userManager,
            INetworkManager networkManager,
            IHttpContextAccessor httpContextAccessor)
            : base(userManager, networkManager, httpContextAccessor)
        {
        }

        /// <inheritdoc />
        protected override Task HandleRequirementAsync(AuthorizationHandlerContext context, NetworkAccessRequirement requirement)
        {
            var ip = HttpContextAccessor.HttpContext?.Connection.RemoteIpAddress;

            // Loopback will be on LAN, so we can accept null.
            if (ip == null || NetworkManager.IsInLocalNetwork(ip))
            {
                context.Succeed(requirement);
            }
            else
            {
                context.Fail();
            }

            return Task.CompletedTask;
        }
    }
}