/*
 * $Id: parse_privacy.c 4720 2008-08-23 10:56:15Z henningw $
 *
 * Copyright (c) 2006 Juha Heinanen
 *
 * This file is part of Kamailio, a free SIP server.
 *
 * Kamailio 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
 *
 * Kamailio 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * History:
 * -------
 * 2006-12-18 Introduced parsing of Privacy header (RFC 3323)
 */

/*!
 * \file
 * \brief Privacy value parser
 * \ingroup parser
 */

#include <stdlib.h>
#include <string.h>
#include "../../dprint.h"
#include "../../trim.h"
#include "parse_privacy.h"
#include "../../parser/msg_parser.h"


/*!
 * Parse a privacy value pointed by start that can be at most max_len long.
 * \return length of matched privacy value on success or NULL otherwise
 */
unsigned int parse_priv_value(char* start, unsigned int max_len,
			      unsigned int* value)
{
    unsigned int len;

    if (!start || !value) {
	LM_ERR("invalid parameter value\n");
	return 0;
    }

    switch (start[0]) {

    case 'c':
    case 'C':
	if(max_len < 8)
	    return 0;
	if (strncasecmp(start, "critical", 8) == 0) {
	    *value = PRIVACY_CRITICAL;
	    len = 8;
	    break;
	} else {
	    return 0;
	}

    case 'h':
    case 'H':
	if (max_len < 6)
	    return 0;
	if (strncasecmp(start, "header", 6) == 0) {
	    *value = PRIVACY_HEADER;
	    len = 6;
	    break;
	}
	if (max_len < 7)
	    return 0;
	if (strncasecmp(start, "history", 7) == 0) {
	    *value = PRIVACY_HISTORY;
	    len = 7;
	    break;
	} else {
	    return 0;
	}

    case 'i':
    case 'I':
	if(max_len < 2)
	    return 0;
	if (start[1] == 'd' || start[1] == 'D') {
	    *value = PRIVACY_ID;
	    len = 2;
	    break;
	} else {
	    return 0;
	}

    case 'n':
    case 'N':
	if(max_len < 4)
	    return 0;
	if (strncasecmp(start, "none", 4) == 0) {
	    *value = PRIVACY_NONE;
	    len = 4;
	    break;
	} else {
	    return 0;
	}

    case 's':
    case 'S':
	if(max_len < 7)
	    return 0;
	if (strncasecmp(start, "session", 7) == 0) {
	    *value = PRIVACY_SESSION;
	    len = 7;
	    break;
	} else {
	    return 0;
	}

    case 'u':
    case 'U':
	if(max_len < 4)
	    return 0;
	if (strncasecmp(start, "user", 4) == 0) {
	    *value = PRIVACY_USER;
	    len = 4;
	    break;
	} else {
	    return 0;
	}

    default:
	return 0;
    }

    if(len < max_len) {
	if(start[len] != '\0' && start[len] != ';' && start[len] != ' '
	   && start[len] != '\t' && start[len] != '\r' && start[len] != '\n')
	    return 0;
    }

    return len;
}


/*!
 * This method is used to parse Privacy HF body, which consist of
 * comma separated list of priv-values.  After parsing, msg->privacy->parsed
 * contains enum bits of privacy values defined in parse_privacy.h.
 * \return 0 on success and -1 on failure. 
 */
int parse_privacy(struct sip_msg *msg)
{
    unsigned int val_len, value, values, len;
    str next;
    char *p, *beyond;

    /* maybe the header is already parsed! */
    if (msg->privacy && msg->privacy->parsed)
	return 0;

    /* parse Privacy HF (there should be only one) */
    if (!msg->privacy &&
	(parse_headers(msg, HDR_PRIVACY_F, 0) == -1 || !msg->privacy)) {
	return -1;
    }

    next.len = msg->privacy->body.len;
    next.s = msg->privacy->body.s;

    trim_leading(&next);

    if (next.len == 0) {
	LM_ERR("no values\n");
	return -1;
    }

    values = 0;
    p = next.s;
    len = next.len;
    beyond = p + len;

    while (p < beyond) {
	if((val_len = parse_priv_value(p, len, &value)) != 0) {
	    values |= value;
	    p = p + val_len;
	    len = len - val_len;
	} else {
	    LM_ERR("invalid privacy value\n");
	    return -1;
	}

	while(p < beyond && (*p == ' ' || *p == '\t'
			     || *p == '\r' || *p == '\n'))
	    p++;

	if(p >= beyond) break;

	if (*p == ';') {
	    p++;
	    while(p < beyond && (*p == ' ' || *p == '\t'
				 || *p == '\r' || *p == '\n'))
		p++;
	    if(p >= beyond) {
		LM_ERR("no privacy value after comma\n");
		return -1;
	    }		
	} else {
	    LM_ERR("semicolon expected\n");
	    return -1;
	}
    }

    if ((values & PRIVACY_NONE) && (values ^ PRIVACY_NONE)) {
	LM_ERR("no other privacy values allowed with 'none'\n");
	return -1;
    }

    msg->privacy->parsed = (void *)(long)values;

    return 0;
}