实现思路
访问PAC网址时将代理信息携带在query参数中，响应时通过nginx修改响应内容
nginx 修改响应内容相关文档：
使用示例
使用示例1：
http://pac.qq.emsfly.cn/pac.SwitchyOmega.txt?proxy=PROXY&host=192.168.1.109&port=808
响应内容：
...
var proxy = 'PROXY 192.168.1.109:808;';
...
使用示例2：
http://pac.qq.emsfly.cn/pac.SwitchyOmega.txt?proxy=SOCKS5&host=192.168.1.109&port=1080
响应内容：
...
var proxy = 'SOCKS5 192.168.1.109:1080;';
...
nginx 配置
nginx.conf
server {
listen 80;
server_name pac.qq.emsfly.cn;
location / {
sub_filter_types *;
sub_filter "__PROXY__" "'$arg_proxy $arg_host:$arg_port;'";
sub_filter_once on;
root "/workspace/nginx/pac/root";
# try_files $uri $uri/ /index.html;
}
# 增加类型后浏览器不能预览文本内容
# add_header Content-Type application/x-ns-proxy-autoconfig;
}
或者，请求格式不正确时返回401状态码
server {
listen 80;
server_name pac.qq.emsfly.cn;
# root指令需在 error_page上一级
root "/workspace/nginx/pac/root";
location /pacplus.txt {
error_page 401 /401.html;
set $condition "$uri $arg_proxy $arg_host $arg_port";
if ($condition !~ "/pacplus.txt .+ .+ .+"){
return 401;
}
sub_filter_types *;
sub_filter "__PROXY__" "'$arg_proxy $arg_host:$arg_port;'";
sub_filter_once on;
# try_files $uri $uri/ /index.html;
}
# 增加类型后浏览器不能预览文本内容
# add_header Content-Type application/x-ns-proxy-autoconfig;
}
401.html
<!DOCTYPE html>
<html>
<head>
<title>Error</title>
<style>
html { color-scheme: light dark; }
body { width: 35em; margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif; }
</style>
</head>
<body>
<h1>The request path format is incorrect.</h1>
<p>Correct format: http://www.example.com/pacplus.txt?proxy=$proxy&host=$host&port=$port.</p>
<p>HTTP eg: http://www.example.com/pacplus.txt?proxy=HTTP&host=127.0.0.1&port=808</p>
<p>HTTPS eg: http://www.example.com/pacplus.txt?proxy=HTTPS&host=127.0.0.1&port=808</p>
<p>SOCKS4 eg: http://www.example.com/pacplus.txt?proxy=SOCKS4&host=127.0.0.1&port=1080</p>
<p>SOCKS5 eg: http://www.example.com/pacplus.txt?proxy=SOCKS5&host=127.0.0.1&port=1080</p>
</body>
</html>
PAC 脚本
pac.txt
var __USERRULES__ = [
"@@@||bxe.comp.360os.com^"
];
var __RULES__ = [
"/.*/",
];
/* eslint-disable */
// Was generated by gfwlist2pac in precise mode
// https://github.com/clowwindy/gfwlist2pac
// 2019-10-06: More 'javascript' way to interaction with main program
// 2019-02-08: Updated to support shadowsocks-windows user rules.
var proxy = __PROXY__;
var userrules = [];
var rules = [];
// convert to abp grammar
var re = /^(@@)?(@@@)?\|\|.*?[^\^]$/;
for (var i = 0; i < __RULES__.length; i++) {
var s = __RULES__[i];
if (s.match(re)) s += "^";
rules.push(s);
}
for (var i = 0; i < __USERRULES__.length; i++) {
var s = __USERRULES__[i];
if (s.match(re)) s += "^";
userrules.push(s);
}
/*
* This file is part of Adblock Plus <http://adblockplus.org/>,
* Copyright (C) 2006-2014 Eyeo GmbH
*
* Adblock Plus is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 3 as
* published by the Free Software Foundation.
*
* Adblock Plus 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.
*
* You should have received a copy of the GNU General Public License
* along with Adblock Plus. If not, see <http://www.gnu.org/licenses/>.
*/
function createDict()
{
var result = {};
result.__proto__ = null;
return result;
}
function getOwnPropertyDescriptor(obj, key)
{
if (obj.hasOwnProperty(key))
{
return obj[key];
}
return null;
}
function extend(subclass, superclass, definition)
{
if (Object.__proto__)
{
definition.__proto__ = superclass.prototype;
subclass.prototype = definition;
}
else
{
var tmpclass = function(){}, ret;
tmpclass.prototype = superclass.prototype;
subclass.prototype = new tmpclass();
subclass.prototype.constructor = superclass;
for (var i in definition)
{
if (definition.hasOwnProperty(i))
{
subclass.prototype[i] = definition[i];
}
}
}
}
function Filter(text)
{
this.text = text;
this.subscriptions = [];
}
Filter.prototype = {
text: null,
subscriptions: null,
toString: function()
{
return this.text;
}
};
Filter.knownFilters = createDict();
Filter.elemhideRegExp = /^([^\/\*\|\@"!]*?)#(\@)?(?:([\w\-]+|\*)((?:\([\w\-]+(?:[$^*]?=[^\(\)"]*)?\))*)|#([^{}]+))$/;
Filter.regexpRegExp = /^(@@)?(@@@)?\/.*\/(?:\$~?[\w\-]+(?:=[^,\s]+)?(?:,~?[\w\-]+(?:=[^,\s]+)?)*)?$/;
Filter.optionsRegExp = /\$(~?[\w\-]+(?:=[^,\s]+)?(?:,~?[\w\-]+(?:=[^,\s]+)?)*)$/;
Filter.fromText = function(text)
{
if (text in Filter.knownFilters)
{
return Filter.knownFilters[text];
}
var ret;
if (text.charAt(0) == "!")
{
ret = new CommentFilter(text);
}
else
{
ret = RegExpFilter.fromText(text);
}
Filter.knownFilters[ret.text] = ret;
return ret;
};
function InvalidFilter(text, reason)
{
Filter.call(this, text);
this.reason = reason;
}
extend(InvalidFilter, Filter, {
reason: null
});
function CommentFilter(text)
{
Filter.call(this, text);
}
extend(CommentFilter, Filter, {
});
function ActiveFilter(text, domains)
{
Filter.call(this, text);
this.domainSource = domains;
}
extend(ActiveFilter, Filter, {
domainSource: null,
domainSeparator: null,
ignoreTrailingDot: true,
domainSourceIsUpperCase: false,
getDomains: function()
{
var prop = getOwnPropertyDescriptor(this, "domains");
if (prop)
{
return prop;
}
var domains = null;
if (this.domainSource)
{
var source = this.domainSource;
if (!this.domainSourceIsUpperCase)
{
source = source.toUpperCase();
}
var list = source.split(this.domainSeparator);
if (list.length == 1 && (list[0]).charAt(0) != "~")
{
domains = createDict();
domains[""] = false;
if (this.ignoreTrailingDot)
{
list[0] = list[0].replace(/\.+$/, "");
}
domains[list[0]] = true;
}
else
{
var hasIncludes = false;
for (var i = 0; i < list.length; i++)
{
var domain = list[i];
if (this.ignoreTrailingDot)
{
domain = domain.replace(/\.+$/, "");
}
if (domain == "")
{
continue;
}
var include;
if (domain.charAt(0) == "~")
{
include = false;
domain = domain.substr(1);
}
else
{
include = true;
hasIncludes = true;
}
if (!domains)
{
domains = createDict();
}
domains[domain] = include;
}
domains[""] = !hasIncludes;
}
this.domainSource = null;
}
return this.domains;
},
sitekeys: null,
isActiveOnDomain: function(docDomain, sitekey)
{
if (this.getSitekeys() && (!sitekey || this.getSitekeys().indexOf(sitekey.toUpperCase()) < 0))
{
return false;
}
if (!this.getDomains())
{
return true;
}
if (!docDomain)
{
return this.getDomains()[""];
}
if (this.ignoreTrailingDot)
{
docDomain = docDomain.replace(/\.+$/, "");
}
docDomain = docDomain.toUpperCase();
while (true)
{
if (docDomain in this.getDomains())
{
return this.domains[docDomain];
}
var nextDot = docDomain.indexOf(".");
if (nextDot < 0)
{
break;
}
docDomain = docDomain.substr(nextDot + 1);
}
return this.domains[""];
},
isActiveOnlyOnDomain: function(docDomain)
{
if (!docDomain || !this.getDomains() || this.getDomains()[""])
{
return false;
}
if (this.ignoreTrailingDot)
{
docDomain = docDomain.replace(/\.+$/, "");
}
docDomain = docDomain.toUpperCase();
for (var domain in this.getDomains())
{
if (this.domains[domain] && domain != docDomain && (domain.length <= docDomain.length || domain.indexOf("." + docDomain) != domain.length - docDomain.length - 1))
{
return false;
}
}
return true;
}
});
function RegExpFilter(text, regexpSource, contentType, matchCase, domains, thirdParty, sitekeys)
{
ActiveFilter.call(this, text, domains, sitekeys);
if (contentType != null)
{
this.contentType = contentType;
}
if (matchCase)
{
this.matchCase = matchCase;
}
if (thirdParty != null)
{
this.thirdParty = thirdParty;
}
if (sitekeys != null)
{
this.sitekeySource = sitekeys;
}
if (regexpSource.length >= 2 && regexpSource.charAt(0) == "/" && regexpSource.charAt(regexpSource.length - 1) == "/")
{
var regexp = new RegExp(regexpSource.substr(1, regexpSource.length - 2), this.matchCase ? "" : "i");
this.regexp = regexp;
}
else
{
this.regexpSource = regexpSource;
}
}
extend(RegExpFilter, ActiveFilter, {
domainSourceIsUpperCase: true,
length: 1,
domainSeparator: "|",
regexpSource: null,
getRegexp: function()
{
var prop = getOwnPropertyDescriptor(this, "regexp");
if (prop)
{
return prop;
}
var source = this.regexpSource.replace(/\*+/g, "*").replace(/\^\|$/, "^").replace(/\W/g, "\\$&").replace(/\\\*/g, ".*").replace(/\\\^/g, "(?:[\\x00-\\x24\\x26-\\x2C\\x2F\\x3A-\\x40\\x5B-\\x5E\\x60\\x7B-\\x7F]|$)").replace(/^\\\|\\\|/, "^[\\w\\-]+:\\/+(?!\\/)(?:[^\\/]+\\.)?").replace(/^\\\|/, "^").replace(/\\\|$/, "$").replace(/^(\.\*)/, "").replace(/(\.\*)$/, "");
var regexp = new RegExp(source, this.matchCase ? "" : "i");
this.regexp = regexp;
return regexp;
},
contentType: 2147483647,
matchCase: false,
thirdParty: null,
sitekeySource: null,
getSitekeys: function()
{
var prop = getOwnPropertyDescriptor(this, "sitekeys");
if (prop)
{
return prop;
}
var sitekeys = null;
if (this.sitekeySource)
{
sitekeys = this.sitekeySource.split("|");
this.sitekeySource = null;
}
this.sitekeys = sitekeys;
return this.sitekeys;
},
matches: function(location, contentType, docDomain, thirdParty, sitekey)
{
if (this.getRegexp().test(location) && this.isActiveOnDomain(docDomain, sitekey))
{
return true;
}
return false;
}
});
RegExpFilter.prototype["0"] = "#this";
RegExpFilter.fromText = function(text)
{
var blocking = true;
var proxied = false;
var origText = text;
if (text.indexOf("@@@") == 0) {
proxied = true;
text = text.substr(3);
}
else if (text.indexOf("@@") == 0)
{
blocking = false;
text = text.substr(2);
}
var contentType = null;
var matchCase = null;
var domains = null;
var sitekeys = null;
var thirdParty = null;
var collapse = null;
var options;
var match = text.indexOf("$") >= 0 ? Filter.optionsRegExp.exec(text) : null;
if (match)
{
options = match[1].toUpperCase().split(",");
text = match.input.substr(0, match.index);
for (var _loopIndex6 = 0; _loopIndex6 < options.length; ++_loopIndex6)
{
var option = options[_loopIndex6];
var value = null;
var separatorIndex = option.indexOf("=");
if (separatorIndex >= 0)
{
value = option.substr(separatorIndex + 1);
option = option.substr(0, separatorIndex);
}
option = option.replace(/-/, "_");
if (option in RegExpFilter.typeMap)
{
if (contentType == null)
{
contentType = 0;
}
contentType |= RegExpFilter.typeMap[option];
}
else if (option.charAt(0) == "~" && option.substr(1) in RegExpFilter.typeMap)
{
if (contentType == null)
{
contentType = RegExpFilter.prototype.contentType;
}
contentType &= ~RegExpFilter.typeMap[option.substr(1)];
}
else if (option == "MATCH_CASE")
{
matchCase = true;
}
else if (option == "~MATCH_CASE")
{
matchCase = false;
}
else if (option == "DOMAIN" && typeof value != "undefined")
{
domains = value;
}
else if (option == "THIRD_PARTY")
{
thirdParty = true;
}
else if (option == "~THIRD_PARTY")
{
thirdParty = false;
}
else if (option == "COLLAPSE")
{
collapse = true;
}
else if (option == "~COLLAPSE")
{
collapse = false;
}
else if (option == "SITEKEY" && typeof value != "undefined")
{
sitekeys = value;
}
else
{
return new InvalidFilter(origText, "Unknown option " + option.toLowerCase());
}
}
}
if (!blocking && (contentType == null || contentType & RegExpFilter.typeMap.DOCUMENT) && (!options || options.indexOf("DOCUMENT") < 0) && !/^\|?[\w\-]+:/.test(text))
{
if (contentType == null)
{
contentType = RegExpFilter.prototype.contentType;
}
contentType &= ~RegExpFilter.typeMap.DOCUMENT;
}
try
{
if (proxied) {
return new ProxiedFilter(origText, text, contentType, matchCase, domains, thirdParty, sitekeys, collapse);
}
if (blocking)
{
return new BlockingFilter(origText, text, contentType, matchCase, domains, thirdParty, sitekeys, collapse);
}
else
{
return new WhitelistFilter(origText, text, contentType, matchCase, domains, thirdParty, sitekeys);
}
}
catch (e)
{
return new InvalidFilter(origText, e);
}
};
RegExpFilter.typeMap = {
OTHER: 1,
SCRIPT: 2,
IMAGE: 4,
STYLESHEET: 8,
OBJECT: 16,
SUBDOCUMENT: 32,
DOCUMENT: 64,
XBL: 1,
PING: 1,
XMLHTTPREQUEST: 2048,
OBJECT_SUBREQUEST: 4096,
DTD: 1,
MEDIA: 16384,
FONT: 32768,
BACKGROUND: 4,
POPUP: 268435456,
ELEMHIDE: 1073741824
};
RegExpFilter.prototype.contentType &= ~ (RegExpFilter.typeMap.ELEMHIDE | RegExpFilter.typeMap.POPUP);
function BlockingFilter(text, regexpSource, contentType, matchCase, domains, thirdParty, sitekeys, collapse)
{
RegExpFilter.call(this, text, regexpSource, contentType, matchCase, domains, thirdParty, sitekeys);
this.collapse = collapse;
}
extend(BlockingFilter, RegExpFilter, {
collapse: null
});
function WhitelistFilter(text, regexpSource, contentType, matchCase, domains, thirdParty, sitekeys)
{
RegExpFilter.call(this, text, regexpSource, contentType, matchCase, domains, thirdParty, sitekeys);
}
extend(WhitelistFilter, RegExpFilter, {
});
function ProxiedFilter(text, regexpSource, contentType, matchCase, domains, thirdParty, sitekeys)
{
RegExpFilter.call(this, text, regexpSource, contentType, matchCase, domains, thirdParty, sitekeys);
}
extend(ProxiedFilter, RegExpFilter, {
});
function Matcher()
{
this.clear();
}
Matcher.prototype = {
filterByKeyword: null,
keywordByFilter: null,
clear: function()
{
this.filterByKeyword = createDict();
this.keywordByFilter = createDict();
},
add: function(filter)
{
if (filter.text in this.keywordByFilter)
{
return;
}
var keyword = this.findKeyword(filter);
var oldEntry = this.filterByKeyword[keyword];
if (typeof oldEntry == "undefined")
{
this.filterByKeyword[keyword] = filter;
}
else if (oldEntry.length == 1)
{
this.filterByKeyword[keyword] = [oldEntry, filter];
}
else
{
oldEntry.push(filter);
}
this.keywordByFilter[filter.text] = keyword;
},
remove: function(filter)
{
if (!(filter.text in this.keywordByFilter))
{
return;
}
var keyword = this.keywordByFilter[filter.text];
var list = this.filterByKeyword[keyword];
if (list.length <= 1)
{
delete this.filterByKeyword[keyword];
}
else
{
var index = list.indexOf(filter);
if (index >= 0)
{
list.splice(index, 1);
if (list.length == 1)
{
this.filterByKeyword[keyword] = list[0];
}
}
}
delete this.keywordByFilter[filter.text];
},
findKeyword: function(filter)
{
var result = "";
var text = filter.text;
if (Filter.regexpRegExp.test(text))
{
return result;
}
var match = Filter.optionsRegExp.exec(text);
if (match)
{
text = match.input.substr(0, match.index);
}
if (text.substr(0, 2) == "@@")
{
text = text.substr(2);
}
var candidates = text.toLowerCase().match(/[^a-z0-9%*][a-z0-9%]{3,}(?=[^a-z0-9%*])/g);
if (!candidates)
{
return result;
}
var hash = this.filterByKeyword;
var resultCount = 16777215;
var resultLength = 0;
for (var i = 0, l = candidates.length; i < l; i++)
{
var candidate = candidates[i].substr(1);
var count = candidate in hash ? hash[candidate].length : 0;
if (count < resultCount || count == resultCount && candidate.length > resultLength)
{
result = candidate;
resultCount = count;
resultLength = candidate.length;
}
}
return result;
},
hasFilter: function(filter)
{
return filter.text in this.keywordByFilter;
},
getKeywordForFilter: function(filter)
{
if (filter.text in this.keywordByFilter)
{
return this.keywordByFilter[filter.text];
}
else
{
return null;
}
},
_checkEntryMatch: function(keyword, location, contentType, docDomain, thirdParty, sitekey)
{
var list = this.filterByKeyword[keyword];
for (var i = 0; i < list.length; i++)
{
var filter = list[i];
if (filter == "#this")
{
filter = list;
}
if (filter.matches(location, contentType, docDomain, thirdParty, sitekey))
{
return filter;
}
}
return null;
},
matchesAny: function(location, contentType, docDomain, thirdParty, sitekey)
{
var candidates = location.toLowerCase().match(/[a-z0-9%]{3,}/g);
if (candidates === null)
{
candidates = [];
}
candidates.push("");
for (var i = 0, l = candidates.length; i < l; i++)
{
var substr = candidates[i];
if (substr in this.filterByKeyword)
{
var result = this._checkEntryMatch(substr, location, contentType, docDomain, thirdParty, sitekey);
if (result)
{
return result;
}
}
}
return null;
}
};
function CombinedMatcher()
{
this.blacklist = new Matcher();
this.whitelist = new Matcher();
this.resultCache = createDict();
}
CombinedMatcher.maxCacheEntries = 1000;
CombinedMatcher.prototype = {
blacklist: null,
whitelist: null,
resultCache: null,
cacheEntries: 0,
clear: function()
{
this.blacklist.clear();
this.whitelist.clear();
this.resultCache = createDict();
this.cacheEntries = 0;
},
add: function(filter)
{
if (filter instanceof WhitelistFilter)
{
this.whitelist.add(filter);
}
else
{
this.blacklist.add(filter);
}
if (this.cacheEntries > 0)
{
this.resultCache = createDict();
this.cacheEntries = 0;
}
},
remove: function(filter)
{
if (filter instanceof WhitelistFilter)
{
this.whitelist.remove(filter);
}
else
{
this.blacklist.remove(filter);
}
if (this.cacheEntries > 0)
{
this.resultCache = createDict();
this.cacheEntries = 0;
}
},
findKeyword: function(filter)
{
if (filter instanceof WhitelistFilter)
{
return this.whitelist.findKeyword(filter);
}
else
{
return this.blacklist.findKeyword(filter);
}
},
hasFilter: function(filter)
{
if (filter instanceof WhitelistFilter)
{
return this.whitelist.hasFilter(filter);
}
else
{
return this.blacklist.hasFilter(filter);
}
},
getKeywordForFilter: function(filter)
{
if (filter instanceof WhitelistFilter)
{
return this.whitelist.getKeywordForFilter(filter);
}
else
{
return this.blacklist.getKeywordForFilter(filter);
}
},
isSlowFilter: function(filter)
{
var matcher = filter instanceof WhitelistFilter ? this.whitelist : this.blacklist;
if (matcher.hasFilter(filter))
{
return !matcher.getKeywordForFilter(filter);
}
else
{
return !matcher.findKeyword(filter);
}
},
matchesAnyInternal: function(location, contentType, docDomain, thirdParty, sitekey)
{
var candidates = location.toLowerCase().match(/[a-z0-9%]{3,}/g);
if (candidates === null)
{
candidates = [];
}
candidates.push("");
var blacklistHit = null;
for (var i = 0, l = candidates.length; i < l; i++)
{
var substr = candidates[i];
if (substr in this.whitelist.filterByKeyword)
{
var result = this.whitelist._checkEntryMatch(substr, location, contentType, docDomain, thirdParty, sitekey);
if (result)
{
return result;
}
}
if (substr in this.blacklist.filterByKeyword && blacklistHit === null)
{
blacklistHit = this.blacklist._checkEntryMatch(substr, location, contentType, docDomain, thirdParty, sitekey);
}
}
return blacklistHit;
},
matchesAny: function(location, docDomain)
{
var key = location + " " + docDomain + " ";
if (key in this.resultCache)
{
return this.resultCache[key];
}
var result = this.matchesAnyInternal(location, 0, docDomain, null, null);
if (this.cacheEntries >= CombinedMatcher.maxCacheEntries)
{
this.resultCache = createDict();
this.cacheEntries = 0;
}
this.resultCache[key] = result;
this.cacheEntries++;
return result;
}
};
var userrulesMatcher = new CombinedMatcher();
var defaultMatcher = new CombinedMatcher();
var direct = 'DIRECT;';
for (var i = 0; i < userrules.length; i++) {
userrulesMatcher.add(Filter.fromText(userrules[i]));
}
for (var i = 0; i < rules.length; i++) {
defaultMatcher.add(Filter.fromText(rules[i]));
}
// PAC has no v6 support, it sucks
var ip4Re = /^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$/
var privateNet = [
["10.0.0.0", "255.0.0.0"],
["127.0.0.0", "255.0.0.0"],
["172.16.0.0", "255.240.0.0"],
["192.168.0.0", "255.255.0.0"],
]
function FindProxyForURL(url, host) {
if (host.match(ip4Re)) {
for (var i = 0; i < privateNet.length; i++) {
if (isInNet(host, privateNet[i][0], privateNet[i][1])) return direct;
}
}
var proxied = "PROXY 127.0.0.1:27001;";
var userrulesMatchResult = userrulesMatcher.matchesAny(url, host);
if (userrulesMatchResult instanceof ProxiedFilter) {
return proxied;
}
if (userrulesMatchResult instanceof BlockingFilter) {
return proxy;
}
if (userrulesMatchResult instanceof WhitelistFilter) {
return direct;
}
// Hack for Geosite, it provides a whitelist...
var defaultMatchResult = defaultMatcher.matchesAny(url, host);
if (defaultMatchResult instanceof ProxiedFilter) {
return proxied;
}
if (defaultMatchResult instanceof WhitelistFilter) {
return direct;
}
if (defaultMatchResult instanceof BlockingFilter) {
return proxy;
}
return direct;
}
