ip_client.c

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/*
 * Copyright (c) 2009 Lukas Mejdrech
 * 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.
 */

#include <errno.h>
#include <sys/types.h>

#include <ip_client.h>
#include <packet_client.h>
#include <ip_header.h>

#include <net/packet.h>

size_t ip_client_header_length(packet_t *packet)
{
        ip_header_t *header;

        header = (ip_header_t *) packet_get_data(packet);
        if (!header || (packet_get_data_length(packet) < sizeof(ip_header_t)))
                return 0;

        return IP_HEADER_LENGTH(header);
}

int
ip_client_get_pseudo_header(ip_protocol_t protocol, struct sockaddr *src,
    socklen_t srclen, struct sockaddr *dest, socklen_t destlen,
    size_t data_length, void **header, size_t *headerlen)
{
        ipv4_pseudo_header_t *header_in;
        struct sockaddr_in *address_in;

        if (!header || !headerlen)
                return EBADMEM;

        if (!src || !dest || srclen <= 0 ||
            (((size_t) srclen < sizeof(struct sockaddr))) ||
            (srclen != destlen) || (src->sa_family != dest->sa_family)) {
                return EINVAL;
        }

        switch (src->sa_family) {
        case AF_INET:
                if (srclen != sizeof(struct sockaddr_in))
                        return EINVAL;
                
                *headerlen = sizeof(*header_in);
                header_in = (ipv4_pseudo_header_t *) malloc(*headerlen);
                if (!header_in)
                        return ENOMEM;

                bzero(header_in, *headerlen);
                address_in = (struct sockaddr_in *) dest;
                header_in->destination_address = address_in->sin_addr.s_addr;
                address_in = (struct sockaddr_in *) src;
                header_in->source_address = address_in->sin_addr.s_addr;
                header_in->protocol = protocol;
                header_in->data_length = htons(data_length);
                *header = header_in;
                return EOK;

        // TODO IPv6
#if 0
        case AF_INET6:
                if (addrlen != sizeof(struct sockaddr_in6))
                        return EINVAL;

                address_in6 = (struct sockaddr_in6 *) addr;
                return EOK;
#endif

        default:
                return EAFNOSUPPORT;
        }
}

int
ip_client_prepare_packet(packet_t *packet, ip_protocol_t protocol, ip_ttl_t ttl,
    ip_tos_t tos, int dont_fragment, size_t ipopt_length)
{
        ip_header_t *header;
        uint8_t *data;
        size_t padding;

        /*
         * Compute the padding if IP options are set
         * multiple of 4 bytes
         */
        padding =  ipopt_length % 4;
        if (padding) {
                padding = 4 - padding;
                ipopt_length += padding;
        }

        /* Prefix the header */
        data = (uint8_t *) packet_prefix(packet, sizeof(ip_header_t) + padding);
        if (!data)
                return ENOMEM;

        /* Add the padding */
        while (padding--)
                data[sizeof(ip_header_t) + padding] = IPOPT_NOOP;

        /* Set the header */
        header = (ip_header_t *) data;
        SET_IP_HEADER_LENGTH(header,
            (IP_COMPUTE_HEADER_LENGTH(sizeof(ip_header_t) + ipopt_length)));
        header->ttl = (ttl ? ttl : IPDEFTTL);
        header->tos = tos;
        header->protocol = protocol;

        if (dont_fragment)
                SET_IP_HEADER_FLAGS(header, IPFLAG_DONT_FRAGMENT);

        return EOK;
}

int
ip_client_process_packet(packet_t *packet, ip_protocol_t *protocol,
    ip_ttl_t *ttl, ip_tos_t *tos, int *dont_fragment, size_t *ipopt_length)
{
        ip_header_t *header;

        header = (ip_header_t *) packet_get_data(packet);
        if (!header || (packet_get_data_length(packet) < sizeof(ip_header_t)))
                return ENOMEM;

        if (protocol)
                *protocol = header->protocol;
        if (ttl)
                *ttl = header->ttl;
        if (tos)
                *tos = header->tos;
        if (dont_fragment)
                *dont_fragment = GET_IP_HEADER_FLAGS(header) & IPFLAG_DONT_FRAGMENT;
        if (ipopt_length) {
                *ipopt_length = IP_HEADER_LENGTH(header) - sizeof(ip_header_t);
                return sizeof(ip_header_t);
        } else {
                return IP_HEADER_LENGTH(header);
        }
}

int
ip_client_set_pseudo_header_data_length(void *header, size_t headerlen,
    size_t data_length)
{
        ipv4_pseudo_header_t *header_in;

        if (!header)
                return EBADMEM;

        if (headerlen == sizeof(ipv4_pseudo_header_t)) {
                header_in = (ipv4_pseudo_header_t *) header;
                header_in->data_length = htons(data_length);
                return EOK;
        // TODO IPv6
        } else {
                return EINVAL;
        }
}

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