1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
|
# Pleroma: A lightweight social networking server
# Copyright © 2017-2022 Pleroma Authors <https://pleroma.social/>
# SPDX-License-Identifier: AGPL-3.0-only
defmodule Pleroma.Web.RichMedia.Parser do
require Logger
@config_impl Application.compile_env(:pleroma, [__MODULE__, :config_impl], Pleroma.Config)
defp parsers do
Pleroma.Config.get([:rich_media, :parsers])
end
def parse(nil), do: nil
@spec parse(String.t()) :: {:ok, map()} | {:error, any()}
def parse(url) do
with :ok <- validate_page_url(url),
{:ok, data} <- parse_url(url) do
data = Map.put(data, "url", url)
{:ok, data}
end
end
defp parse_url(url) do
with {:ok, %Tesla.Env{body: html}} <- Pleroma.Web.RichMedia.Helpers.rich_media_get(url),
{:ok, html} <- Floki.parse_document(html) do
html
|> maybe_parse()
|> clean_parsed_data()
|> check_parsed_data()
end
end
defp maybe_parse(html) do
Enum.reduce_while(parsers(), %{}, fn parser, acc ->
case parser.parse(html, acc) do
data when data != %{} -> {:halt, data}
_ -> {:cont, acc}
end
end)
end
defp check_parsed_data(%{"title" => title} = data)
when is_binary(title) and title != "" do
{:ok, data}
end
defp check_parsed_data(data) do
{:error, {:invalid_metadata, data}}
end
defp clean_parsed_data(data) do
data
|> Enum.reject(fn {key, val} ->
not match?({:ok, _}, Jason.encode(%{key => val}))
end)
|> Map.new()
end
@spec validate_page_url(URI.t() | binary()) :: :ok | :error
defp validate_page_url(page_url) when is_binary(page_url) do
validate_tld = @config_impl.get([Pleroma.Formatter, :validate_tld])
page_url
|> Linkify.Parser.url?(validate_tld: validate_tld)
|> parse_uri(page_url)
end
defp validate_page_url(%URI{host: host, scheme: "https"}) do
cond do
Linkify.Parser.ip?(host) ->
:error
host in @config_impl.get([:rich_media, :ignore_hosts], []) ->
:error
get_tld(host) in @config_impl.get([:rich_media, :ignore_tld], []) ->
:error
true ->
:ok
end
end
defp validate_page_url(_), do: :error
defp parse_uri(true, url) do
url
|> URI.parse()
|> validate_page_url
end
defp parse_uri(_, _), do: :error
defp get_tld(host) do
host
|> String.split(".")
|> Enum.reverse()
|> hd
end
end
|
