我们在下面有以下内容来匹配SIP Via标头。我们正在使用boost C ++ regex
Via: SIP/2.0/UDP 192.168.1.4:62486;rport;branch=z9hG4bK-524287-1---3ff9a622846c0a01;stck=3449406834;received=90.206.135.26
正则表达式:
std::regex g_Via;
g_Via("(^Via:\\s+SIP/2\\.0/UDP\\s+)(((\\w|\\.|-)+):(\\d+))((;\\s*rport=(\\d+))|(;stck=(\\d+))|(;[^;\\n\\s]+)*)(\\s*$)",std::regex_constants::icase)
std::match_results<std::string::const_iterator> result;
bool valid = std::regex_match(line, result, g_Via);
if(valid)
{
std::string rport = result[8].str();
std::string stckval = result[9].str();
// use these values
}
我们想要的是获取IP地址后的rport,received和stck参数。我们可以使用上面的表达式获取IP地址,但是在获取单个参数时会遇到问题。
rport参数可以是; rport或; rport = 14838 即独立或有价值。
我们遇到的问题是诸如的分支; branch =; received =可以处于不同的位置
答案 0 :(得分:3)
我不建议使用正则表达式“解析”SIP标头。
正如评论中已提到的,处理属性变得笨拙。此外,您会发现规范中有细微的细节(rfc 2616 / rfc 822),这使得很难做到正确。
我之前使用Boost Spirit创建了一个SIP头解析器:
我实际上是直播创建该解析器。以下是您希望观看的直播视频:part #1,part #2,part #3和part #4。
这里使用解析器生成器的好处是你不会最终得到原始匹配组,但可以直接解析为有用的东西,例如。
using Headers = std::map<std::string, std::string>;
<强> Live On Coliru 强>
//#define BOOST_SPIRIT_DEBUG
#include <boost/fusion/adapted/std_pair.hpp>
#include <boost/spirit/include/qi.hpp>
#include <boost/algorithm/string/trim.hpp>
#include <map>
using Headers = std::map<std::string, std::string>;
template <typename It> Headers parse_headers(It first, It last)
{
using namespace boost::spirit::qi;
auto& crlf = "\r\n";
auto& tspecials = " \t><@,;:\\\"/][?=}{:";
rule<It, std::string()> token, value;
token = +~char_(tspecials); // FIXME? should filter CTLs
value = *(char_ - (crlf >> &(~blank | eoi)));
BOOST_SPIRIT_DEBUG_NODES((token)(value));
//value = *(omit[ crlf >> !(~blank | eoi) ] >> attr(' ') | (char_ - crlf));
Headers headers;
bool ok = phrase_parse(first, last, (token >> ':' >> value) % crlf >> omit[*lit(crlf)], blank, headers);
#ifdef DEBUG
if (ok) std::cerr << "DEBUG: Parse success\n";
else std::cerr << "DEBUG: Parse failed\n";
if (first!=last) std::cerr << "DEBUG: Remaining unparsed input: '" << std::string(first,last) << "'\n";
#endif
if (ok && (first==last))
return headers;
throw std::runtime_error("Parse error in headers\n"); // TODO FIXME
}
int main()
{
boost::spirit::istream_iterator iter(std::cin >> std::noskipws), end;
for (auto& header : parse_headers(iter, end)) {
std::cout << "Key: '" << header.first << "', Value: '" << header.second << "'\n";
}
}
输入:
Via: SIP/2.0/UDP 10.10.1.99:5060;branch=z9hG4bK343bf628;rport
Contact: <sip:15@10.10.1.99>
Call-ID: 326371826c80e17e6cf6c29861eb2933@10.10.1.99
CSeq: 102 INVITE
User-Agent: Asterisk PBX
Max-Forwards: 70
Date: Wed, 06 Dec 2009 14:12:45 GMT
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY
Supported: replaces
Content-Type: application/sdp
Content-Length: 258
From: "Test 15" <sip:15@10.10.1.99>
; tag = fromtag
To: <sip:13@10.10.1.13>;tag=totag
打印输出
Key: 'Allow', Value: 'INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY'
Key: 'CSeq', Value: '102 INVITE'
Key: 'Call-ID', Value: '326371826c80e17e6cf6c29861eb2933@10.10.1.99'
Key: 'Contact', Value: '<sip:15@10.10.1.99>'
Key: 'Content-Length', Value: '258'
Key: 'Content-Type', Value: 'application/sdp'
Key: 'Date', Value: 'Wed, 06 Dec 2009 14:12:45 GMT'
Key: 'From', Value: '"Test 15" <sip:15@10.10.1.99>
; tag = fromtag'
Key: 'Max-Forwards', Value: '70'
Key: 'Supported', Value: 'replaces'
Key: 'To', Value: '<sip:13@10.10.1.13>;tag=totag'
Key: 'User-Agent', Value: 'Asterisk PBX'
Key: 'Via', Value: 'SIP/2.0/UDP 10.10.1.99:5060;branch=z9hG4bK343bf628;rport'
答案 1 :(得分:2)
根据您正在使用的语言,处理属性可能最好与正则表达式分开进行。您可以使用正则表达式来提取每个属性(或者可能是整个属性字符串 - 从第一个;
到结尾的所有内容)。之后,您可以使用;
作为分隔符来拆分属性字符串。例如,Python和PHP都有简单的功能(Python中为split()
,PHP中为explode()
)。然后,您可以按=
拆分每个属性,以将属性名称与属性值分开。
答案 2 :(得分:1)
您使用了太多我无法跟踪的群组,所以我删除了大部分群组。这将适用于您提到的任何语言。
(?<Named> groups)
,但您可以轻松将其更改为正常(group)
。我用它们是实用的。<强>正则表达式强>
^Via:\s+SIP\/2\.0\/UDP\s+ # header
([-.\w]+):(\d+) # IP (group 1) and port (group 2)
(?: # ITERATE
(?<received>;received=[.\d]+) # received (group "received")
| #
(?<rport>;rport # rport (group "rport")
(?:=(?<rportval>[0-9]+))? # with optional num (group "rportval")
) #
| #
(?<stck>;stck=\d+) # stck (group "stck")
| #
;[^;\n\s=]+(?:=[^;]+)? # any other param (not captured)
)* # Repeat iteration *
\s*$ # to EoL
一衬垫:
^Via:\s+SIP\/2\.0\/UDP\s+([-.\w]+):(\d+)(?:(?<received>;received=[.\d]+)|(?<rport>;rport(?:=(?<rportval>[0-9]+))?)|(?<stck>;stck=\d+)|;[^;\n\s=]+(?:=[^;]+)?)*\s*$
<强>代码强>
使用Boost.Regex:
#include <iostream>
#include <boost/regex.hpp>
using namespace std;
using namespace boost;
int main () {
string subject = "Via: SIP/2.0/UDP 192.168.1.4:62486;rport=12345;branch=z9hG4bK-524287-1---3ff9a622846c0a01;stck=3449406834;received=90.206.135.26";
string pattern = "^Via:\\s+SIP/2\\.0/UDP\\s+([-.\\w]+):([0-9]+)(?:(?<received>;received=[.0-9]+)|(?<rport>;rport(?:=(?<rportval>[0-9]+))?)|(?<stck>;stck=[0-9]+)|;[^;\\n\\s=]+(?:=[^;]*)?)*\\s*$";
smatch match;
const regex re(pattern);
if (regex_search(subject, match, re)) {
string received = match["received"];
string rport = match["rport"];
string rportval = match["rportval"];
string stck = match["stck"];
cout << "rport = " << rport << endl << "rportval = " << rportval << endl;
} else {
cout << "NO MATCH" << endl;
}
return 0;
}
输出:
rport = ;rport=12345
rportval = 12345