lib/inet/udp.c

	udp.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 1991-2003 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 *
 * udp.c, Code implementing the UDP internet protocol.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

#include <sys/types.h>
#include <socket_impl.h>
#include <socket_inet.h>
#include <sys/salib.h>
#include <sys/socket.h>
#include <netinet/in_systm.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/udp.h>

#include "udp_inet.h"
#include "ipv4.h"
#include "ipv4_impl.h"
#include "mac.h"
#include "mac_impl.h"
#include "v4_sum_impl.h"
#include <sys/bootdebug.h>

/* Checksum all architectures */
static int udp_cksum_flag = TRUE;   /* checksum on if set */

/*
 * Initialize the udp-specific parts of a socket.
 */
void
udp_socket_init(struct inetboot_socket *isp)
{
    isp->type = INETBOOT_DGRAM;
    isp->proto = IPPROTO_UDP;
    isp->input[TRANSPORT_LVL] = udp_input;
    isp->output[TRANSPORT_LVL] = udp_output;
    isp->close[TRANSPORT_LVL] = NULL;
    isp->headerlen[TRANSPORT_LVL] = udp_header_len;
    isp->ports = udp_ports;
}

/*
 * Return the size of an UDP header
 */
/* ARGSUSED */
int
udp_header_len(struct inetgram *igm)
{
    return (sizeof (struct udphdr));
}

/*
 * Return the requested port number in network order.
 */
in_port_t
udp_ports(uint16_t *udphp, enum Ports request)
{
    if (request == SOURCE)
        return (((struct udphdr *)udphp)->uh_sport);
    return (((struct udphdr *)udphp)->uh_dport);
}

/*
 * Process the IPv4 datagram that IPv4 has given us. We:
 *
 *  1) Checksum the datagram if checksum is turned on.
 *  2) Strip the udp header from the inetgram.
 *  3) Return the number of TRANSPORT frames for success, -1 if a
 *      failure occurred.
 *
 * Arguments: index: index into the open socket table, ip is the inetgram
 * we got from IPv4, which will contain the udp header and all the data.
 */
int
udp_input(int index)
{
    int frames = 0, header_len;
    struct inetgram *igp, *ugp = NULL;
    struct udphdr   *udphp;
    mblk_t *mp;

#ifdef DEBUG
    printf("udp_input(%d) ###############################\n", index);
#endif
    while ((igp = sockets[index].inq) != NULL) {
        if (igp->igm_level != TRANSPORT_LVL) {
#ifdef  DEBUG
            printf("udp_input(%d): level %d datagram discarded.\n",
                index, igp->igm_level);
#endif  /* DEBUG */
            del_gram(&sockets[index].inq, igp, TRUE);
            continue;
        }
        mp = igp->igm_mp;
        udphp = (struct udphdr *)(mp->b_rptr +
            IPH_HDR_LENGTH(mp->b_rptr));
        header_len = (sockets[index].headerlen[TRANSPORT_LVL])(NULL);
        mp->b_rptr = ((unsigned char *)udphp) + header_len;
        mp->b_wptr = ((unsigned char *)udphp) + ntohs(udphp->uh_ulen);

        /* generate checksum */
        if (udp_cksum_flag && udphp->uh_sum != 0) {
            if (udp_chksum(udphp, &igp->igm_saddr.sin_addr,
                &igp->igm_target, sockets[index].proto) != 0) {
                dprintf("udp_input(%d): bad udp chksum "
                    "from %s.\n", index,
                    inet_ntoa(igp->igm_saddr.sin_addr));
                del_gram(&sockets[index].inq, igp, TRUE);
                continue;
            }
        }

        /* validate port number */
        if (sockets[index].bind.sin_port != udphp->uh_dport) {
            dprintf("udp_input(%d): Unexpected port number: "
                "%d != %d from %s.\n", index,
                ntohs(udphp->uh_dport), ntohs(
                sockets[index].bind.sin_port),
                inet_ntoa(igp->igm_saddr.sin_addr));
            del_gram(&sockets[index].inq, igp, TRUE);
            continue;
        }

        igp->igm_level = APP_LVL;
        del_gram(&sockets[index].inq, igp, FALSE);
        add_grams(&ugp, igp);
        frames++;
    }
    add_grams(&sockets[index].inq, ugp);

    return (frames);
}

/*
 * Create a UDP datagram given the data and sockaddr_in we got from sendto().
 * We will calculate the checksum if checksumming is turned on, and fill in
 * appropriate length and port fields. We convert the inetgram from a
 * block of data into a udp datagram... Returns the number of bytes contained
 * in the udp datagram (including header).
 *
 * Arguments: index: index into the open socket table, ogp is the inetgram
 * we got from sendto(), which will contain just the data and sockaddr_in.
 */
int
udp_output(int index, struct inetgram *ogp)
{
    struct udphdr   *udphp;
    mblk_t      *mp;

#ifdef  DEBUG
    printf("udp_output(%d): 0x%x, %d\n", index, ogp->igm_mp,
        ogp->igm_mp->b_wptr - ogp->igm_mp->b_rptr);
#endif  /* DEBUG */

    mp = ogp->igm_mp;
    mp->b_rptr -= sizeof (struct udphdr);
    udphp = (struct udphdr *)(mp->b_rptr);

    udphp->uh_dport = ogp->igm_saddr.sin_port;
    if (sockets[index].bound)
        udphp->uh_sport = sockets[index].bind.sin_port;
    else
        udphp->uh_sport = ogp->igm_saddr.sin_port;
    udphp->uh_ulen = htons(mp->b_wptr - mp->b_rptr);
    udphp->uh_sum = 0;

    if (udp_cksum_flag) {
        udphp->uh_sum = udp_chksum(udphp, &sockets[index].bind.sin_addr,
            &ogp->igm_saddr.sin_addr, sockets[index].proto);
    }

    ogp->igm_level = NETWORK_LVL;

    return (0);
}