aboutsummaryrefslogtreecommitdiff
path: root/background/page_actions_server.js
blob: bb4c34f21af8c7334c43867d4d64b5f85002ee13 (about) (plain)
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
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
/**
 * This file is part of Haketilo.
 *
 * Function: Serving page actions to content scripts.
 *
 * Copyright (C) 2021 Wojtek Kosior
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * As additional permission under GNU GPL version 3 section 7, you
 * may distribute forms of that code without the copy of the GNU
 * GPL normally required by section 4, provided you include this
 * license notice and, in case of non-source distribution, a URL
 * through which recipients can access the Corresponding Source.
 * If you modify file(s) with this exception, you may extend this
 * exception to your version of the file(s), but you are not
 * obligated to do so. If you do not wish to do so, delete this
 * exception statement from your version.
 *
 * As a special exception to the GPL, any HTML file which merely
 * makes function calls to this code, and for that purpose
 * includes it by reference shall be deemed a separate work for
 * copyright law purposes. If you modify this code, you may extend
 * this exception to your version of the code, but you are not
 * obligated to do so. If you do not wish to do so, delete this
 * exception statement from your version.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 *
 * I, Wojtek Kosior, thereby promise not to sue for violation of this file's
 * license. Although I request that you do not make use this code in a
 * proprietary program, I am not going to enforce this in court.
 */

/*
 * IMPORTS_START
 * IMPORT get_storage
 * IMPORT light_storage
 * IMPORT TYPE_PREFIX
 * IMPORT CONNECTION_TYPE
 * IMPORT browser
 * IMPORT listen_for_connection
 * IMPORT sha256
 * IMPORT make_ajax_request
 * IMPORTS_END
 */

var storage;
var handler;

// TODO: parallelize script fetching
async function send_scripts(components, port, processed_bags)
{
    for (let [prefix, name] of components) {
	if (prefix === TYPE_PREFIX.BAG) {
	    if (processed_bags.has(name)) {
		console.log(`preventing recursive inclusion of bag ${name}`);
		continue;
	    }

	    var bag = storage.get(TYPE_PREFIX.BAG, name);

	    if (bag === undefined) {
		console.log(`no bag in storage for key ${name}`);
		continue;
	    }

	    processed_bags.add(name);
	    await send_scripts(bag, port, processed_bags);

	    processed_bags.delete(name);
	} else {
	    let script_text = await get_script_text(name);
	    if (script_text === undefined)
		continue;

	    port.postMessage(["inject", [script_text]]);
	}
    }
}

async function get_script_text(script_name)
{
    try {
	let script_data = storage.get(TYPE_PREFIX.SCRIPT, script_name);
	if (script_data === undefined) {
	    console.log(`missing data for ${script_name}`);
	    return;
	}
	let script_text = script_data.text;
	if (!script_text)
	    script_text = await fetch_remote_script(script_data);
	return script_text;
    } catch (e) {
	console.log(e);
    }
}

async function fetch_remote_script(script_data)
{
    try {
	let xhttp = await make_ajax_request("GET", script_data.url);
	if (xhttp.status === 200) {
	    let computed_hash = sha256(xhttp.responseText);
	    if (computed_hash !== script_data.hash) {
		console.log(`Bad hash for ${script_data.url}\n    got ${computed_hash} instead of ${script_data.hash}`);
		return;
	    }
	    return xhttp.responseText;
	} else {
	    console.log("script not fetched: " + script_data.url);
	    return;
	}
    } catch (e) {
	console.log(e);
    }
}

function handle_message(port, message, handler)
{
    port.onMessage.removeListener(handler[0]);
    console.debug(`Loading payload '${message.payload}'.`);

    const processed_bags = new Set();

    send_scripts([message.payload], port, processed_bags);
}

function new_connection(port)
{
    console.log("new page actions connection!");
    let handler = [];
    handler.push(m => handle_message(port, m, handler));
    port.onMessage.addListener(handler[0]);
}

async function start_page_actions_server()
{
    storage = await get_storage();

    listen_for_connection(CONNECTION_TYPE.PAGE_ACTIONS, new_connection);
}

/*
 * EXPORTS_START
 * EXPORT start_page_actions_server
 * EXPORTS_END
 */