primitives.c

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/*
 * Copyright 2010 John-Mark Bell <jmb@netsurf-browser.org>
 *
 * This file is part of NetSurf, http://www.netsurf-browser.org/
 *
 * NetSurf 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; version 2 of the License.
 *
 * NetSurf 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, see <http://www.gnu.org/licenses/>.
 */
 
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
 
#include "netsurf/inttypes.h"
#include "utils/http/primitives.h"
 
/**
 * Skip past linear whitespace in input
 *
 * \param input  Pointer to current input byte. Updated on exit.
 */
void http__skip_LWS(const char **input)
{
        const char *pos = *input;
 
        while (*pos == ' ' || *pos == '\t')
                pos++;
 
        *input = pos;
}
 
/**
 * Determine if a character is valid for an HTTP token
 *
 * \param c  Character to consider
 * \return True if character is valid, false otherwise
 */
static bool http_is_token_char(uint8_t c)
{
        /* [ 32 - 126 ] except ()<>@,;:\"/[]?={} SP HT */
 
        if (c <= ' ' || 126 < c)
                return false;
 
        return (strchr("()<>@,;:\\\"/[]?={}", c) == NULL);
}
 
/**
 * Parse an HTTP token
 *
 * \param input  Pointer to current input byte. Updated on exit.
 * \param value  Pointer to location to receive on-heap token value.
 * \return NSERROR_OK on success,
 *         NSERROR_NOMEM on memory exhaustion,
 *         NSERROR_NOT_FOUND if no token could be parsed
 *
 * The returned value is owned by the caller
 */
nserror http__parse_token(const char **input, lwc_string **value)
{
        const uint8_t *start = (const uint8_t *) *input;
        const uint8_t *end;
        lwc_string *token;
 
        end = start;
        while (http_is_token_char(*end))
                end++;
 
        if (end == start)
                return NSERROR_NOT_FOUND;
 
        if (lwc_intern_string((const char *) start, 
                        end - start, &token) != lwc_error_ok)
                return NSERROR_NOMEM;
 
        *value = token;
        *input = (const char *) end;
 
        return NSERROR_OK;
}
 
/**
 * Parse an HTTP quoted-string
 *
 * \param input  Pointer to current input byte. Updated on exit.
 * \param value  Pointer to location to receive on-heap string value.
 * \return NSERROR_OK on success,
 *         NSERROR_NOMEM on memory exhaustion,
 *         NSERROR_NOT_FOUND if no string could be parsed
 *
 * The returned value is owned by the caller
 */
nserror http__parse_quoted_string(const char **input, lwc_string **value)
{
        const uint8_t *start = (const uint8_t *) *input;
        const uint8_t *end;
        uint8_t c;
        lwc_string *string_value;
 
        /* <"> *( qdtext | quoted-pair ) <">
         * qdtext = any TEXT except <">
         * quoted-pair = "\" CHAR
         * TEXT = [ HT, CR, LF, 32-126, 128-255 ]
         * CHAR = [ 0 - 127 ]
         *
         * \todo TEXT may contain non 8859-1 chars encoded per RFC 2047
         * \todo Support quoted-pairs
         */
 
        if (*start != '"')
                return NSERROR_NOT_FOUND;
 
        end = start = start + 1;
 
        c = *end;
        while (c == '\t' || c == '\r' || c == '\n' || 
                        c == ' ' || c == '!' ||
                        ('#' <= c && c <= 126) || c > 127) {
                end++;
                c = *end;
        }
 
        if (*end != '"')
                return NSERROR_NOT_FOUND;
 
        if (lwc_intern_string((const char *) start, end - start, 
                        &string_value) != lwc_error_ok)
                return NSERROR_NOMEM;
 
        *value = string_value;
 
        *input = (const char *) end + 1;
 
        return NSERROR_OK;
}