yate/contrib/ysip/util.cpp

/**
 * util.cpp
 * Yet Another SIP Stack
 * This file is part of the YATE Project http://YATE.null.ro 
 *
 * Yet Another Telephony Engine - a fully featured software PBX and IVR
 * Copyright (C) 2004-2006 Null Team
 *
 * 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 2 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
 */

#include "util.h"

#include <string.h>

namespace TelEngine {

// Utility function, checks if a character is a folded line continuation
bool isContinuationBlank(char c)
{
    return ((c == ' ') || (c == '\t'));
}

// Utility function, returns an unfolded line and advances the pointer
String* getUnfoldedLine(const char** buf, int* len)
{
    String* res = new String;
    const char* b = *buf;
    const char* s = b;
    int l = *len;
    int e = 0;
    for (;(l > 0); ++b, --l) {
	bool goOut = false;
	switch (*b) {
	    case '\r':
		// CR is optional but skip over it if exists
		if ((l > 0) && (b[1] == '\n')) {
		    ++b;
		    --l;
		}
	    case '\n':
		++b;
		--l;
		{
		    String line(s,e);
		    *res << line;
		}
		// Skip over any continuation characters at start of next line
		goOut = true;
		while ((l > 0) && isContinuationBlank(b[0])) {
		    ++b;
		    --l;
		    goOut = false;
		}
		s = b;
		e = 0;
		if (!goOut) {
		    --b;
		    ++l;
		}
		break;
	    case '\0':
		// Should not happen - but let's accept what we got
		Debug(DebugMild,"Unexpected NUL character while unfolding lines");
		*res << s;
		goOut = true;
		// End parsing
		b += l;
		l = 0;
		e = 0;
		break;
	    default:
		// Just count this character - we'll pick it later
		++e;
	}
	// Exit without adjusting p and l
	if (goOut)
	    break;
    }
    *buf = b;
    *len = l;
    // Collect any leftover characters
    if (e) {
	String line(s,e);
	*res << line;
    }
    res->trimBlanks();
    return res;
}

static const char* compactForms[] = {
    "a", "Accept-Contact",
    "i", "Call-ID",
    "m", "Contact",
    "e", "Content-Encoding",
    "l", "Content-Length",
    "c", "Content-Type",
    "f", "From",
    "r", "Refer-To",
    "b", "Referred-By",
    "j", "Reject-Contact",
    "d", "Request-Disposition",
    "x", "Session-Expires",
    "s", "Subject",
    "k", "Supported",
    "t", "To",
    "v", "Via",
    0 };

// Utility function, returns an uncompacted header name
const char* uncompactForm(const char* header)
{
    if (header && header[0] && !header[1]) {
	char c = header[0];
	const char **p = compactForms;
	for (; *p; p += 2)
	    if (**p == c)
		return *++p;
    }
    return header;
}

// Utility function, returns a compacted header name
const char* compactForm(const char* header)
{
    if (header && *header) {
	const char **p = compactForms;
	for (; *p; p += 2)
	    if (!::strcasecmp(p[1],header))
		return p[0];
    }
    return header;
}

// Utility function, puts quotes around a string
void addQuotes(String& str)
{
    str.trimBlanks();
    int l = str.length();
    if ((l < 2) || (str[0] != '"') || (str[l-1] != '"'))
	str = "\"" + str + "\"";
}

// Utility function, removes quotes around a string
void delQuotes(String& str)
{
    str.trimBlanks();
    int l = str.length();
    if ((l >= 2) && (str[0] == '"') && (str[l-1] == '"')) {
	str = str.substr(1,l-2);
	str.trimBlanks();
    }
}

// Utility function, puts quotes around a string
String quote(const String& str)
{
    String tmp(str);
    addQuotes(tmp);
    return tmp;
}

}

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