parse_retry_after.c

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/* 
 * $Id$ 
 *
 * Copyright (C) 2007 iptelorg GmbH
 *
 * This file is part of ser, a free SIP server.
 *
 * ser 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
 *
 * ser 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:
 * --------
 *  2007-07-27  created by andrei
 */

#include "../comp_defs.h"
#include "parse_retry_after.h"
#include "parser_f.h"  /* eat_space_end and so on */
#include "parse_def.h"
#include "../dprint.h"
#include "../mem/mem.h"

char* parse_retry_after(char *buf, char* end, unsigned* after, int* err)
{
        char *t;
        int i;
        unsigned val;
        
        val=0;
        t=buf;
        
        t=eat_lws_end(t, end);
        if (t>=end) goto error;
        for (i=0; t<end; i++,t++){
                if ((*t >= '0') && (*t <= '9')){
                        val=val*10+(*t-'0');
                }else{
                        switch(*t){
                                /* for now we don't care about retry-after params or comment*/
                                case ' ':
                                case '\t':
                                case ';':
                                case '\r':
                                case '\n':
                                        goto found;
                                default:
                                        /* invalid char */
                                        goto error;
                        }
                }
        }
        goto error_nocrlf; /* end reached without encountering cr or lf */
found:
        if (i>10 || i==0) /* too many  or too few digits */
                goto error;
        *after=val;
        /* find the end of header */
        for (; t<end; t++){
                if (*t=='\n'){
                        if (((t+1)<end) && (*(t+1)=='\r'))
                                t++;
                        if (((t+1)<end) && (*(t+1)==' ' || *(t+1)=='\t')){
                                t++;
                                continue; /* line folding ... */
                        }
                        *err=0;
                        return t+1;
                }
        }
error_nocrlf:
        LOG(L_ERR, "ERROR: parse_retry_after: strange EoHF\n");
        goto error;
error:
        LOG(L_ERR, "ERROR: parse_retry_after: bad Retry-After header \n");
        *err=1;
        return t;
}