source: mainline/uspace/lib/http/src/headers.c@ 4b9213d

/*
 * Copyright (c) 2013 Martin Sucha
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup http
 * @{
 */
/**
 * @file
 */

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <str.h>
#include <macros.h>

#include <http/http.h>
#include <http/ctype.h>

#define HTTP_HEADER_LINE "%s: %s\r\n"

void http_header_init(http_header_t *header)
{
        link_initialize(&header->link);
        header->name = NULL;
        header->value = NULL;
}

http_header_t *http_header_create(const char *name, const char *value)
{
        http_header_t *header = malloc(sizeof(http_header_t));
        if (header == NULL)
                return NULL;
        http_header_init(header);

        header->name = str_dup(name);
        if (header->name == NULL) {
                free(header);
                return NULL;
        }

        header->value = str_dup(value);
        if (header->value == NULL) {
                free(header->name);
                free(header);
                return NULL;
        }

        return header;
}

void http_header_destroy(http_header_t *header)
{
        free(header->name);
        free(header->value);
        free(header);
}

ssize_t http_header_encode(http_header_t *header, char *buf, size_t buf_size)
{
        /* TODO properly split long header values */
        return snprintf(buf, buf_size,
            HTTP_HEADER_LINE, header->name, header->value);
}

errno_t http_header_receive_name(receive_buffer_t *rb,
    receive_buffer_mark_t *name_end)
{
        char c = 0;
        do {
                if (name_end)
                        recv_mark_update(rb, name_end);

                errno_t rc = recv_char(rb, &c, true);
                if (rc != EOK)
                        return rc;
        } while (is_token(c));

        if (c != ':')
                return EINVAL;

        return EOK;
}

errno_t http_header_receive_value(receive_buffer_t *rb,
    receive_buffer_mark_t *value_start, receive_buffer_mark_t *value_end)
{
        errno_t rc = EOK;
        char c = 0;

        /* Ignore any inline LWS */
        while (true) {
                if (value_start)
                        recv_mark_update(rb, value_start);

                rc = recv_char(rb, &c, false);
                if (rc != EOK)
                        return rc;

                if (c != ' ' && c != '\t')
                        break;

                rc = recv_char(rb, &c, true);
                if (rc != EOK)
                        return rc;
        }

        while (true) {
                recv_mark_update(rb, value_end);

                rc = recv_char(rb, &c, true);
                if (rc != EOK)
                        return rc;

                if (c != '\r' && c != '\n')
                        continue;

                size_t nrecv;
                rc = recv_discard(rb, (c == '\r' ? '\n' : '\r'), &nrecv);
                if (rc != EOK)
                        return rc;

                rc = recv_char(rb, &c, false);
                if (rc != EOK)
                        return rc;

                if (c != ' ' && c != '\t')
                        break;

                /* Ignore the char */
                rc = recv_char(rb, &c, true);
                if (rc != EOK)
                        return rc;
        }

        return EOK;
}

errno_t http_header_receive(receive_buffer_t *rb, http_header_t *header,
    size_t size_limit, size_t *out_bytes_used)
{
        receive_buffer_mark_t mark_start;
        receive_buffer_mark_t mark_end;

        recv_mark(rb, &mark_start);
        recv_mark(rb, &mark_end);

        errno_t rc = http_header_receive_name(rb, &mark_end);
        if (rc != EOK)
                goto end;

        size_t name_size = mark_end.offset - mark_start.offset;
        if (size_limit > 0 && name_size > size_limit) {
                rc = ELIMIT;
                goto end;
        }

        char *name = NULL;
        rc = recv_cut_str(rb, &mark_start, &mark_end, &name);
        if (rc != EOK)
                goto end;

        rc = http_header_receive_value(rb, &mark_start, &mark_end);
        if (rc != EOK)
                goto end_with_name;

        size_t value_size = mark_end.offset - mark_start.offset;
        if (size_limit > 0 && (name_size + value_size) > size_limit) {
                rc = ELIMIT;
                goto end_with_name;
        }

        char *value = NULL;
        rc = recv_cut_str(rb, &mark_start, &mark_end, &value);
        if (rc != EOK)
                goto end_with_name;

        if (out_bytes_used)
                *out_bytes_used = name_size + value_size;

        header->name = name;
        header->value = value;
        goto end;
end_with_name:
        free(name);
end:
        recv_unmark(rb, &mark_start);
        recv_unmark(rb, &mark_end);
        return rc;
}

/** Normalize HTTP header value
 *
 * @see RFC2616 section 4.2
 */
void http_header_normalize_value(char *value)
{
        size_t read_index = 0;
        size_t write_index = 0;

        while (is_lws(value[read_index]))
                read_index++;

        while (value[read_index] != 0) {
                if (is_lws(value[read_index])) {
                        while (is_lws(value[read_index]))
                                read_index++;

                        if (value[read_index] != 0)
                                value[write_index++] = ' ';

                        continue;
                }

                value[write_index++] = value[read_index++];
        }

        value[write_index] = 0;
}

/** Test if two header names are equivalent
 *
 */
bool http_header_name_match(const char *name_a, const char *name_b)
{
        return str_casecmp(name_a, name_b) == 0;
}

void http_headers_init(http_headers_t *headers)
{
        list_initialize(&headers->list);
}

errno_t http_headers_find_single(http_headers_t *headers, const char *name,
    http_header_t **out_header)
{
        http_header_t *found = NULL;
        http_headers_foreach(*headers, header) {
                if (!http_header_name_match(header->name, name))
                        continue;

                if (found == NULL) {
                        found = header;
                } else {
                        return HTTP_EMULTIPLE_HEADERS;
                }
        }

        if (found == NULL)
                return HTTP_EMISSING_HEADER;

        *out_header = found;
        return EOK;
}

errno_t http_headers_append(http_headers_t *headers, const char *name,
    const char *value)
{
        http_header_t *header = http_header_create(name, value);
        if (header == NULL)
                return ENOMEM;

        http_headers_append_header(headers, header);
        return EOK;
}

errno_t http_headers_set(http_headers_t *headers, const char *name,
    const char *value)
{
        http_header_t *header = NULL;
        errno_t rc = http_headers_find_single(headers, name, &header);
        if (rc != EOK && rc != HTTP_EMISSING_HEADER)
                return rc;

        if (rc == HTTP_EMISSING_HEADER)
                return http_headers_append(headers, name, value);

        char *new_value = str_dup(value);
        if (new_value == NULL)
                return ENOMEM;

        free(header->value);
        header->value = new_value;
        return EOK;
}

errno_t http_headers_get(http_headers_t *headers, const char *name, char **value)
{
        http_header_t *header = NULL;
        errno_t rc = http_headers_find_single(headers, name, &header);
        if (rc != EOK)
                return rc;

        *value = header->value;
        return EOK;
}

errno_t http_headers_receive(receive_buffer_t *rb, http_headers_t *headers,
    size_t limit_alloc, unsigned limit_count)
{
        errno_t rc = EOK;
        unsigned added = 0;

        while (true) {
                char c = 0;
                rc = recv_char(rb, &c, false);
                if (rc != EOK)
                        goto error;

                if (c == '\n' || c == '\r')
                        break;

                if (limit_count > 0 && added >= limit_count) {
                        rc = ELIMIT;
                        goto error;
                }

                http_header_t *header = malloc(sizeof(http_header_t));
                if (header == NULL) {
                        rc = ENOMEM;
                        goto error;
                }
                http_header_init(header);

                size_t header_size;
                rc = http_header_receive(rb, header, limit_alloc, &header_size);
                if (rc != EOK) {
                        free(header);
                        goto error;
                }
                limit_alloc -= header_size;

                http_headers_append_header(headers, header);
                added++;
        }

        return EOK;
error:
        while (added-- > 0) {
                link_t *link = list_last(&headers->list);
                http_header_t *header = list_get_instance(link, http_header_t, link);
                http_headers_remove(headers, header);
                http_header_destroy(header);
        }
        return rc;
}

void http_headers_clear(http_headers_t *headers)
{
        link_t *link = list_first(&headers->list);
        while (link != NULL) {
                link_t *next = list_next(link, &headers->list);
                http_header_t *header = list_get_instance(link, http_header_t, link);
                list_remove(link);
                http_header_destroy(header);
                link = next;
        }
}

/** @}
 */