forked from AkkomaGang/akkoma
110 lines
3.2 KiB
Elixir
110 lines
3.2 KiB
Elixir
# Pleroma: A lightweight social networking server
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# Copyright © 2015-2020 Tymon Tobolski <https://github.com/teamon/tesla/blob/master/lib/tesla/middleware/follow_redirects.ex>
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# Copyright © 2020 Pleroma Authors <https://pleroma.social/>
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# SPDX-License-Identifier: AGPL-3.0-only
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defmodule Pleroma.HTTP.Middleware.FollowRedirects do
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@moduledoc """
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Pool-aware version of https://github.com/teamon/tesla/blob/master/lib/tesla/middleware/follow_redirects.ex
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Follow 3xx redirects
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## Options
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- `:max_redirects` - limit number of redirects (default: `5`)
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"""
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alias Pleroma.Gun.ConnectionPool
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@behaviour Tesla.Middleware
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@max_redirects 5
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@redirect_statuses [301, 302, 303, 307, 308]
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@impl Tesla.Middleware
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def call(env, next, opts \\ []) do
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max = Keyword.get(opts, :max_redirects, @max_redirects)
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redirect(env, next, max)
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end
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defp redirect(env, next, left) do
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opts = env.opts[:adapter]
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case Tesla.run(env, next) do
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{:ok, %{status: status} = res} when status in @redirect_statuses and left > 0 ->
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release_conn(opts)
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case Tesla.get_header(res, "location") do
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nil ->
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{:ok, res}
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location ->
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location = parse_location(location, res)
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case get_conn(location, opts) do
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{:ok, opts} ->
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%{env | opts: Keyword.put(env.opts, :adapter, opts)}
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|> new_request(res.status, location)
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|> redirect(next, left - 1)
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e ->
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e
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end
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end
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{:ok, %{status: status}} when status in @redirect_statuses ->
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release_conn(opts)
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{:error, {__MODULE__, :too_many_redirects}}
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{:error, _} = e ->
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release_conn(opts)
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e
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other ->
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unless opts[:body_as] == :chunks do
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release_conn(opts)
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end
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other
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end
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end
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defp get_conn(location, opts) do
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uri = URI.parse(location)
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case ConnectionPool.get_conn(uri, opts) do
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{:ok, conn} ->
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{:ok, Keyword.merge(opts, conn: conn)}
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e ->
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e
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end
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end
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defp release_conn(opts) do
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ConnectionPool.release_conn(opts[:conn])
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end
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# The 303 (See Other) redirect was added in HTTP/1.1 to indicate that the originally
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# requested resource is not available, however a related resource (or another redirect)
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# available via GET is available at the specified location.
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# https://tools.ietf.org/html/rfc7231#section-6.4.4
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defp new_request(env, 303, location), do: %{env | url: location, method: :get, query: []}
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# The 307 (Temporary Redirect) status code indicates that the target
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# resource resides temporarily under a different URI and the user agent
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# MUST NOT change the request method (...)
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# https://tools.ietf.org/html/rfc7231#section-6.4.7
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defp new_request(env, 307, location), do: %{env | url: location}
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defp new_request(env, _, location), do: %{env | url: location, query: []}
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defp parse_location("https://" <> _rest = location, _env), do: location
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defp parse_location("http://" <> _rest = location, _env), do: location
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defp parse_location(location, env) do
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env.url
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|> URI.parse()
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|> URI.merge(location)
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|> URI.to_string()
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end
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end
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