lib/inet/ipv4.c

	ipv4.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 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 *
 * ipv4.c, Code implementing the IPv4 internet protocol.
 */

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

#include <sys/types.h>
#include <socket_impl.h>
#include <socket_inet.h>
#include <sys/sysmacros.h>
#include <sys/socket.h>
#include <netinet/in_systm.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/udp.h>
#include <net/if_arp.h>
#include <sys/promif.h>
#include <sys/bootconf.h>
#include <sys/fcntl.h>
#include <sys/salib.h>

#include "icmp4.h"
#include "ipv4.h"
#include "ipv4_impl.h"
#include "mac.h"
#include "mac_impl.h"
#include "v4_sum_impl.h"
#include <sys/bootdebug.h>

static struct ip_frag   fragment[FRAG_MAX]; /* ip fragment buffers */
static int      fragments;      /* Number of fragments */
static uint8_t      ttl = MAXTTL;       /* IP ttl */
static struct in_addr   myip;           /* our network-order IP addr */
static struct in_addr   mynet;          /* net-order netaddr */
static struct in_addr   netmask =
    { 0xff, 0xff, 0xff, 0xff };     /* our network-order netmask */
static boolean_t    netmask_set = B_FALSE;  /* has anyone set netmask? */
static struct in_addr   defaultrouter;      /* net-order defaultrouter */
static int      promiscuous;        /* promiscuous mode */
static struct routing table[IPV4_ROUTE_TABLE_SIZE];

static uint16_t g_ip_id;

#ifdef  DEBUG
#define FRAG_DEBUG
#endif  /* DEBUG */

#ifdef FRAG_DEBUG
/*
 * display the fragment list. For debugging purposes.
 */
static void
frag_disp(uint16_t size)
{
    int i;
    uint_t  total = 0;

    printf("Dumping fragment info: (%d)\n\n", fragments);
    printf("More:\tOffset:\tDatap:\t\tIPid:\t\tIPlen:\tIPhlen:\n");
    for (i = 0; i < FRAG_MAX; i++) {
        if (fragment[i].mp == NULL)
            continue;
        printf("%d\t%d\t0x%x\t%d\t\t%d\t%d\n", fragment[i].more,
            fragment[i].offset, fragment[i].mp->b_rptr,
            fragment[i].ipid, fragment[i].iplen, fragment[i].iphlen);
        total += (fragment[i].iplen - fragment[i].iphlen);
    }
    printf("Total length is: %d. It should be: %d\n\n", total, size);
}
#endif /* FRAG_DEBUG */

/*
 * This function returns index of fragment 0 of the current fragmented DGRAM
 * (which would contain the transport header). Return the fragment number
 * for success, -1 if we don't yet have the first fragment.
 */
static int
frag_first(void)
{
    int     i;

    if (fragments == 0)
        return (-1);

    for (i = 0; i < FRAG_MAX; i++) {
        if (fragment[i].mp != NULL && fragment[i].offset == 0)
            return (i);
    }
    return (-1);
}

/*
 * This function returns index of the last fragment of the current DGRAM.
 * Returns the fragment number for success, -1 if we don't yet have the
 * last fragment.
 */
static int
frag_last(void)
{
    int     i;

    if (fragments == 0)
        return (-1);

    for (i = 0; i < FRAG_MAX; i++) {
        if (fragment[i].mp != NULL && !fragment[i].more)
            return (i);
    }
    return (-1);
}

/*
 * This function adds a fragment to the current pkt fragment list. Returns
 * FRAG_NOSLOTS if there are no more slots, FRAG_DUP if the fragment is
 * a duplicate, or FRAG_SUCCESS if it is successful.
 */
static int
frag_add(int16_t offset, mblk_t *mp, uint16_t ipid,
    int16_t iplen, int16_t iphlen, uint8_t ipp)
{
    int i;
    int16_t true_offset = IPV4_OFFSET(offset);

    /* first pass - look for duplicates */
    for (i = 0; i < FRAG_MAX; i++) {
        if (fragment[i].mp != NULL &&
            fragment[i].offset == true_offset)
            return (FRAG_DUP);
    }

    /* second pass - fill in empty slot */
    for (i = 0; i < FRAG_MAX; i++) {
        if (fragment[i].mp == NULL) {
            fragment[i].more = (offset & IP_MF);
            fragment[i].offset = true_offset;
            fragment[i].mp = mp;
            fragment[i].ipid = ipid;
            fragment[i].iplen = iplen;
            fragment[i].iphlen = iphlen;
            fragment[i].ipp = ipp;
            fragments++;
            return (FRAG_SUCCESS);
        }
    }
    return (FRAG_NOSLOTS);
}

/*
 * Nuke a fragment.
 */
static void
frag_free(int index)
{
    if (fragment[index].mp != NULL) {
        freeb(fragment[index].mp);
        fragments--;
    }
    bzero((caddr_t)&fragment[index], sizeof (struct ip_frag));
}

/*
 * zero the frag list.
 */
static void
frag_flush(void)
{
    int i;

    for (i = 0; i < FRAG_MAX; i++)
        frag_free(i);

    fragments = 0;
}

/*
 * Analyze the fragment list - see if we captured all our fragments.
 *
 * Returns TRUE if we've got all the fragments, and FALSE if we don't.
 */
static int
frag_chk(void)
{
    int     i, first_frag, last_frag;
    int16_t     actual, total;
    uint16_t    ip_id;
    uint8_t     ipp;

    if (fragments == 0 || (first_frag = frag_first()) < 0 ||
        (last_frag = frag_last()) < 0)
        return (FALSE);

    /*
     * Validate the ipid's of our fragments - nuke those that don't
     * match the id of the first fragment or don't match the IP
     * protocol of the first fragment.
     */
    ip_id = fragment[first_frag].ipid;
    ipp = fragment[first_frag].ipp;
    for (i = 0; i < FRAG_MAX; i++) {
        if (fragment[i].mp != NULL && ip_id != fragment[i].ipid &&
            fragment[i].ipp != ipp) {
#ifdef FRAG_DEBUG
            printf("ipv4: Frag id mismatch: %x != %x\n",
                fragment[i].ipid, ip_id);
#endif /* FRAG_DEBUG */
            frag_free(i);
        }
    }

    if (frag_last() < 0)
        return (FALSE);

    total = fragment[last_frag].offset + fragment[last_frag].iplen -
        fragment[last_frag].iphlen;

    for (i = 0, actual = 0; i < FRAG_MAX; i++)
        actual += (fragment[i].iplen - fragment[i].iphlen);

#ifdef FRAG_DEBUG
    frag_disp(total);
#endif /* FRAG_DEBUG */

    return (total == actual);
}

/*
 * Load the assembled fragments into igp. Returns 0 for success, nonzero
 * otherwise.
 */
static int
frag_load(struct inetgram *igp)
{
    int i;
    int16_t len;
    uint_t  total_len;
    boolean_t first_frag = B_FALSE;
    mblk_t *mp;
    struct ip *iph;
    int first_iph_len;

    if (fragments == 0)
        return (ENOENT);

    mp = igp->igm_mp;
    /* Get the IP header length of the first fragment. */
    i = frag_first();
    assert(i >= 0);
    first_iph_len = fragment[i].iphlen;
    for (i = 0, len = 0, total_len = 0; i < FRAG_MAX; i++) {
        if (fragment[i].mp != NULL) {
            /*
             * Copy just the data (omit the ip header of all
             * fragments except the first one which contains
             * all the info...)
             */
            if (fragment[i].offset == 0) {
                len = fragment[i].iplen;
                first_frag = B_TRUE;
            } else {
                len = fragment[i].iplen - fragment[i].iphlen;
            }
            total_len += len;
            if (total_len > mp->b_size)
                return (E2BIG);
            if (first_frag) {
                bcopy((caddr_t)(fragment[i].mp->b_rptr),
                    (caddr_t)mp->b_rptr, len);
                first_frag = B_FALSE;
            } else {
                bcopy((caddr_t)(fragment[i].mp->b_rptr +
                    fragment[i].iphlen),
                    (caddr_t)(mp->b_rptr + first_iph_len +
                    fragment[i].offset), len);
            }
            mp->b_wptr += len;
        }
    }
    /* Fix the total length in the IP header. */
    iph = (struct ip *)mp->b_rptr;
    iph->ip_len = htons(total_len);
    return (0);
}

/*
 * Locate a routing table entry based upon arguments. IP addresses expected
 * in network order. Returns index for success, -1 if entry not found.
 */
static int
find_route(uint8_t *flagp, struct in_addr *destp, struct in_addr *gatewayp)
{
    int i, table_entry = -1;

    for (i = 0; table_entry == -1 && i < IPV4_ROUTE_TABLE_SIZE; i++) {
        if (flagp != NULL) {
            if (*flagp & table[i].flag)
                table_entry = i;
        }
        if (destp != NULL) {
            if (destp->s_addr == table[i].dest.s_addr)
                table_entry = i;
            else
                table_entry = -1;
        }
        if (gatewayp != NULL) {
            if (gatewayp->s_addr == table[i].gateway.s_addr)
                table_entry = i;
            else
                table_entry = -1;
        }
    }
    return (table_entry);
}

/*
 * ADD or DEL a routing table entry. Returns 0 for success, -1 and errno
 * otherwise. IP addresses are expected in network order.
 */
int
ipv4_route(int cmd, uint8_t flag, struct in_addr *destp,
    struct in_addr *gatewayp)
{
    static  int routing_table_initialized;
    int     index;
    uint8_t     tmp_flag;

    if (gatewayp == NULL) {
        errno = EINVAL;
        return (-1);
    }

    /* initialize routing table */
    if (routing_table_initialized == 0) {
        for (index = 0; index < IPV4_ROUTE_TABLE_SIZE; index++)
            table[index].flag = RT_UNUSED;
        routing_table_initialized = 1;
    }

    switch (cmd) {
    case IPV4_ADD_ROUTE:
        tmp_flag = (uint8_t)RT_UNUSED;
        if ((index = find_route(&tmp_flag, NULL, NULL)) == -1) {
            dprintf("ipv4_route: routing table full.\n");
            errno = ENOSPC;
            return (-1);
        }
        table[index].flag = flag;
        if (destp != NULL)
            table[index].dest.s_addr = destp->s_addr;
        else
            table[index].dest.s_addr = htonl(INADDR_ANY);
        table[index].gateway.s_addr = gatewayp->s_addr;
        break;
    case IPV4_BAD_ROUTE:
        /* FALLTHRU */
    case IPV4_DEL_ROUTE:
        if ((index = find_route(&flag, destp, gatewayp)) == -1) {
            dprintf("ipv4_route: No such routing entry.\n");
            errno = ENOENT;
            return (-1);
        }
        if (cmd == IPV4_DEL_ROUTE) {
            table[index].flag = RT_UNUSED;
            table[index].dest.s_addr = htonl(INADDR_ANY);
            table[index].gateway.s_addr = htonl(INADDR_ANY);
        } else
            table[index].flag = RT_NG;
    default:
        errno = EINVAL;
        return (-1);
    }
    return (0);
}

/*
 * Return gateway to destination. Returns gateway IP address in network order
 * for success, NULL if no route to destination exists.
 */
struct in_addr *
ipv4_get_route(uint8_t flag, struct in_addr *destp, struct in_addr *gatewayp)
{
    int index;
    if ((index = find_route(&flag, destp, gatewayp)) == -1)
        return (NULL);
    return (&table[index].gateway);
}

/*
 * Initialize the IPv4 generic parts of the socket, as well as the routing
 * table.
 */
void
ipv4_socket_init(struct inetboot_socket *isp)
{
    isp->input[NETWORK_LVL] = ipv4_input;
    isp->output[NETWORK_LVL] = ipv4_output;
    isp->close[NETWORK_LVL] = NULL;
    isp->headerlen[NETWORK_LVL] = ipv4_header_len;
}

/*
 * Initialize a raw ipv4 socket.
 */
void
ipv4_raw_socket(struct inetboot_socket *isp, uint8_t proto)
{
    isp->type = INETBOOT_RAW;
    if (proto == 0)
        isp->proto = IPPROTO_IP;
    else
        isp->proto = proto;
    isp->input[TRANSPORT_LVL] = NULL;
    isp->output[TRANSPORT_LVL] = NULL;
    isp->headerlen[TRANSPORT_LVL] = NULL;
    isp->ports = NULL;
}

/*
 * Return the size of an IPv4 header (no options)
 */
/* ARGSUSED */
int
ipv4_header_len(struct inetgram *igm)
{
    return (sizeof (struct ip));
}

/*
 * Set our source address.
 * Argument is assumed to be host order.
 */
void
ipv4_setipaddr(struct in_addr *ip)
{
    myip.s_addr = htonl(ip->s_addr);
}

/*
 * Returns our current source address in host order.
 */
void
ipv4_getipaddr(struct in_addr *ip)
{
    ip->s_addr = ntohl(myip.s_addr);
}

/*
 * Set our netmask.
 * Argument is assumed to be host order.
 */
void
ipv4_setnetmask(struct in_addr *ip)
{
    netmask_set = B_TRUE;
    netmask.s_addr = htonl(ip->s_addr);
    mynet.s_addr = netmask.s_addr & myip.s_addr; /* implicit */
}

void
ipv4_getnetid(struct in_addr *my_netid)
{
    struct in_addr my_netmask;
    if (mynet.s_addr != 0)
        my_netid->s_addr = ntohl(mynet.s_addr);
    else {
        ipv4_getnetmask(&my_netmask);
        my_netid->s_addr = my_netmask.s_addr & ntohl(myip.s_addr);
    }
}

/*
 * Returns our current netmask in host order.
 * Neither OBP nor the standalone DHCP client mandate
 * that the netmask be specified, so in the absence of
 * a netmask, we attempt to derive it using class-based
 * heuristics.
 */
void
ipv4_getnetmask(struct in_addr *ip)
{
    if (netmask_set || (myip.s_addr == 0))
        ip->s_addr = ntohl(netmask.s_addr);
    else {
        /* base the netmask on our IP address */
        if (IN_CLASSA(ntohl(myip.s_addr)))
            ip->s_addr = ntohl(IN_CLASSA_NET);
        else if (IN_CLASSB(ntohl(myip.s_addr)))
            ip->s_addr = ntohl(IN_CLASSB_NET);
        else
            ip->s_addr = ntohl(IN_CLASSC_NET);
    }
}

/*
 * Set our default router.
 * Argument is assumed to be host order, and *MUST* be on the same network
 * as our source IP address.
 */
void
ipv4_setdefaultrouter(struct in_addr *ip)
{
    defaultrouter.s_addr = htonl(ip->s_addr);
}

/*
 * Returns our current default router in host order.
 */
void
ipv4_getdefaultrouter(struct in_addr *ip)
{
    ip->s_addr = ntohl(defaultrouter.s_addr);
}

/*
 * Toggle promiscuous flag. If set, client disregards destination IP
 * address. Otherwise, only limited broadcast, network broadcast, and
 * unicast traffic get through. Returns previous setting.
 */
int
ipv4_setpromiscuous(int toggle)
{
    int old = promiscuous;

    promiscuous = toggle;

    return (old);
}

/*
 * Set IP TTL.
 */
void
ipv4_setmaxttl(uint8_t cttl)
{
    ttl = cttl;
}

/*
 * Convert an ipv4 address to dotted notation.
 * Returns ptr to statically allocated buffer containing dotted string.
 */
char *
inet_ntoa(struct in_addr ip)
{
    uint8_t *p;
    static char ipaddr[16];

    p = (uint8_t *)&ip.s_addr;
    (void) sprintf(ipaddr, "%u.%u.%u.%u", p[0], p[1], p[2], p[3]);
    return (ipaddr);
}

/*
 * Construct a transport datagram from a series of IP fragments (igp == NULL)
 * or from a single IP datagram (igp != NULL). Return the address of the
 * contructed transport datagram.
 */
struct inetgram *
make_trans_datagram(int index, struct inetgram *igp, struct in_addr ipsrc,
    struct in_addr ipdst, uint16_t iphlen)
{
    uint16_t    trans_len, *transp, new_len;
    int     first_frag, last_frag;
    boolean_t   fragmented;
    struct inetgram *ngp;
    struct ip   *iph;

    fragmented = (igp == NULL);

    ngp = (struct inetgram *)bkmem_zalloc(sizeof (struct inetgram));
    if (ngp == NULL) {
        errno = ENOMEM;
        if (fragmented)
            frag_flush();
        return (NULL);
    }

    if (fragmented) {
        last_frag = frag_last();
        trans_len = fragment[last_frag].offset +
            fragment[last_frag].iplen - fragment[last_frag].iphlen;
        first_frag = frag_first();
        /*
         * The returned buffer contains the IP header of the
         * first fragment.
         */
        trans_len += fragment[first_frag].iphlen;
        transp = (uint16_t *)(fragment[first_frag].mp->b_rptr +
            fragment[first_frag].iphlen);
    } else {
        /*
         * Note that igm_len may not be the real length of an
         * IP packet because some network interface, such as
         * Ethernet, as a minimum frame size.  So we should not
         * use the interface frame size to determine the
         * length of an IP packet.  We should use the IP
         * length field in the IP header.
         */
        iph = (struct ip *)igp->igm_mp->b_rptr;
        trans_len = ntohs(iph->ip_len);
        transp = (uint16_t *)(igp->igm_mp->b_rptr + iphlen);
    }

    ngp->igm_saddr.sin_addr.s_addr = ipsrc.s_addr;
    ngp->igm_saddr.sin_port = sockets[index].ports(transp, SOURCE);
    ngp->igm_target.s_addr = ipdst.s_addr;
    ngp->igm_level = TRANSPORT_LVL;

    /*
     * Align to 16bit value.  Checksum code may require an extra byte
     * for padding.
     */
    new_len = ((trans_len + sizeof (int16_t) - 1) &
        ~(sizeof (int16_t) - 1));
    if ((ngp->igm_mp = allocb(new_len, 0)) == NULL) {
        errno = ENOMEM;
        bkmem_free((caddr_t)ngp, sizeof (struct inetgram));
        if (fragmented)
            frag_flush();
        return (NULL);
    }

    if (fragmented) {
        if (frag_load(ngp) != 0) {
            freeb(ngp->igm_mp);
            bkmem_free((caddr_t)ngp, sizeof (struct inetgram));
            frag_flush();
            return (NULL);
        }
        frag_flush();
    } else {
        bcopy((caddr_t)(igp->igm_mp->b_rptr),
            (caddr_t)ngp->igm_mp->b_rptr, trans_len);
        ngp->igm_mp->b_wptr += trans_len;
    }
    return (ngp);
}

/*
 * ipv4_input: Pull in IPv4 datagrams addressed to us. Handle IP fragmentation
 * (fragments received in any order) and ICMP at this level.
 *
 * Note that because our network is serviced by polling when we expect
 * something (upon a referenced socket), we don't go through the work of
 * locating the appropriate socket a datagram is destined for. We'll only
 * accept data for the referenced socket. This means we don't have
 * asynchronous networking, but since we can't service the net using an
 * interrupt handler, it doesn't do us any good to try to service datagrams
 * destined for sockets other than the referenced one. Data is handled in
 * a fifo manner.
 *
 * The mac layer will grab all frames for us. If we find we don't have all
 * the necessary fragments to reassemble the datagram, we'll call the mac
 * layer again for FRAG_ATTEMPTS to see if it has any more frames.
 *
 * Supported protocols: IPPROTO_IP, IPPROTO_ICMP, IPPROTO_UDP.
 *
 * Returns: number of NETWORK_LVL datagrams placed on socket , -1 if error
 * occurred.
 *
 * Note: errno is set to ETIMEDOUT if fragment reassembly fails.
 */
int
ipv4_input(int index)
{
    int         datagrams = 0;
    int         frag_stat, input_attempts = 0;
    uint16_t        iphlen, iplen, ip_id;
    int16_t         curr_off;
    struct ip       *iphp;
    struct inetgram     *igp, *newgp = NULL, *ipv4_listp = NULL;
    struct in_addr      ipdst, ipsrc;
    mblk_t          *mp;
    enum SockType       type;

#ifdef  DEBUG
    printf("ipv4_input(%d): start ######################################\n",
        index);
#endif  /* DEBUG */

    frag_flush();

ipv4_try_again:

    while ((igp = sockets[index].inq) != NULL) {
        if (igp->igm_level != NETWORK_LVL) {
#ifdef  DEBUG
            printf("ipv4_input(%d): unexpected frame type: %d\n",
                index, igp->igm_level);
#endif  /* DEBUG */
            del_gram(&sockets[index].inq, igp, TRUE);
            continue;
        }
        iphp = (struct ip *)igp->igm_mp->b_rptr;
        if (iphp->ip_v != IPVERSION) {
            dprintf("ipv4_input(%d): IPv%d datagram discarded\n",
            index, iphp->ip_v);
            del_gram(&sockets[index].inq, igp, TRUE);
            continue;
        }
        iphlen = iphp->ip_hl << 2;
        if (iphlen < sizeof (struct ip)) {
            dprintf("ipv4_input(%d): IP msg too short (%d < %u)\n",
                index, iphlen, (uint_t)sizeof (struct ip));
            del_gram(&sockets[index].inq, igp, TRUE);
            continue;
        }
        iplen = ntohs(iphp->ip_len);
        if (iplen > msgdsize(igp->igm_mp)) {
            dprintf("ipv4_input(%d): IP len/buffer mismatch "
                "(%d > %lu)\n", index, iplen, igp->igm_mp->b_size);
            del_gram(&sockets[index].inq, igp, TRUE);
            continue;
        }

        bcopy((caddr_t)&(iphp->ip_dst), (caddr_t)&ipdst,
            sizeof (ipdst));
        bcopy((caddr_t)&(iphp->ip_src), (caddr_t)&ipsrc,
            sizeof (ipsrc));

        /* igp->igm_mp->b_datap is guaranteed to be 64 bit aligned] */
        if (ipv4cksum((uint16_t *)iphp, iphlen) != 0) {
            dprintf("ipv4_input(%d): Bad IP header checksum "
                "(to %s)\n", index, inet_ntoa(ipdst));
            del_gram(&sockets[index].inq, igp, TRUE);
            continue;
        }

        if (!promiscuous) {
            /* validate destination address */
            if (ipdst.s_addr != htonl(INADDR_BROADCAST) &&
                ipdst.s_addr != (mynet.s_addr | ~netmask.s_addr) &&
                ipdst.s_addr != myip.s_addr) {
#ifdef  DEBUG
                printf("ipv4_input(%d): msg to %s discarded.\n",
                    index, inet_ntoa(ipdst));
#endif  /* DEBUG */
                /* not ours */
                del_gram(&sockets[index].inq, igp, TRUE);
                continue;
            }
        }

        /* Intercept ICMP first */
        if (!promiscuous && (iphp->ip_p == IPPROTO_ICMP)) {
            icmp4(igp, iphp, iphlen, ipsrc);
            del_gram(&sockets[index].inq, igp, TRUE);
            continue;
        }

#ifdef  DEBUG
        printf("ipv4_input(%d): processing ID: 0x%x protocol %d "
            "(0x%x) (0x%x,%d)\n",
            index, ntohs(iphp->ip_id), iphp->ip_p, igp, igp->igm_mp,
            igp->igm_mp->b_size);
#endif  /* DEBUG */
        type = sockets[index].type;
        if (type == INETBOOT_RAW) {
            /* No fragmentation - Just the raw packet. */
#ifdef  DEBUG
            printf("ipv4_input(%d): Raw packet.\n", index);
#endif  /* DEBUG */
            del_gram(&sockets[index].inq, igp, FALSE);
            add_grams(&ipv4_listp, igp);
            igp->igm_mp->b_rptr += iphlen;
            igp->igm_mp->b_wptr = igp->igm_mp->b_rptr + iplen;
            datagrams++;
            continue;
        }

        if ((type == INETBOOT_DGRAM && iphp->ip_p != IPPROTO_UDP) ||
            (type == INETBOOT_STREAM && iphp->ip_p != IPPROTO_TCP)) {
            /* Wrong protocol. */
            dprintf("ipv4_input(%d): unexpected protocol: "
                "%d for socket type %d\n", index, iphp->ip_p, type);
            del_gram(&sockets[index].inq, igp, TRUE);
            continue;
        }

        /*
         * The following code is common to both STREAM and DATAGRAM
         * sockets.
         */

        /*
         * Once we process the first fragment, we won't have
         * the transport header, so we'll have to  match on
         * IP id.
         */
        curr_off = ntohs(iphp->ip_off);
        if ((curr_off & ~(IP_DF | IP_MF)) == 0) {
            uint16_t    *transp;

            /* Validate transport header. */
            mp = igp->igm_mp;
            if ((mp->b_wptr - mp->b_rptr - iphlen) <
                sockets[index].headerlen[TRANSPORT_LVL](igp)) {
                dprintf("ipv4_input(%d): datagram 0 "
                    "too small to hold transport header "
                    "(from %s)\n", index, inet_ntoa(ipsrc));
                del_gram(&sockets[index].inq, igp, TRUE);
                continue;
            }

            /*
             * check alignment - transport elements are 16
             * bit aligned..
             */
            transp = (uint16_t *)(mp->b_rptr + iphlen);
            if ((uintptr_t)transp % sizeof (uint16_t)) {
                dprintf("ipv4_input(%d): Transport "
                    "header is not 16-bit aligned "
                    "(0x%lx, from %s)\n", index, (long)transp,
                    inet_ntoa(ipsrc));
                del_gram(&sockets[index].inq, igp, TRUE);
                continue;
            }

            if (curr_off & IP_MF) {
                /* fragment 0 of fragmented datagram */
                ip_id = ntohs(iphp->ip_id);
                frag_stat = frag_add(curr_off, igp->igm_mp,
                    ip_id, iplen, iphlen, iphp->ip_p);
                if (frag_stat != FRAG_SUCCESS) {
#ifdef  FRAG_DEBUG
                    if (frag_stat == FRAG_DUP) {
                        printf("ipv4_input"
                            "(%d): Frag dup.\n", index);
                    } else {
                        printf("ipv4_input"
                            "(%d): too many "
                            "frags\n", index);
                    }
#endif  /* FRAG_DEBUG */
                    del_gram(&sockets[index].inq,
                        igp, TRUE);
                    continue;
                }

                del_gram(&sockets[index].inq, igp, FALSE);
                /* keep the data, lose the inetgram */
                bkmem_free((caddr_t)igp,
                    sizeof (struct inetgram));
#ifdef  FRAG_DEBUG
                printf("ipv4_input(%d): Frag/Off/Id "
                    "(%d/%d/%x)\n", index, fragments,
                    IPV4_OFFSET(curr_off), ip_id);
#endif  /* FRAG_DEBUG */
            } else {
                /* Single, unfragmented datagram */
                newgp = make_trans_datagram(index, igp,
                    ipsrc, ipdst, iphlen);
                if (newgp != NULL) {
                    add_grams(&ipv4_listp, newgp);
                    datagrams++;
                }
                del_gram(&sockets[index].inq, igp,
                    TRUE);
                continue;
            }
        } else {
            /* fragments other than 0 */
            frag_stat = frag_add(curr_off, igp->igm_mp,
                ntohs(iphp->ip_id), iplen, iphlen, iphp->ip_p);

            if (frag_stat == FRAG_SUCCESS) {
#ifdef  FRAG_DEBUG
                printf("ipv4_input(%d): Frag(%d) "
                    "off(%d) id(%x)\n", index,
                    fragments, IPV4_OFFSET(curr_off),
                    ntohs(iphp->ip_id));
#endif  /* FRAG_DEBUG */
                del_gram(&sockets[index].inq, igp, FALSE);
                /* keep the data, lose the inetgram */
                bkmem_free((caddr_t)igp,
                    sizeof (struct inetgram));
            } else {
#ifdef  FRAG_DEBUG
                if (frag_stat == FRAG_DUP)
                    printf("ipv4_input(%d): Frag "
                        "dup.\n", index);
                else {
                    printf("ipv4_input(%d): too "
                        "many frags\n", index);
                }
#endif  /* FRAG_DEBUG */
                del_gram(&sockets[index].inq, igp, TRUE);
                continue;
            }
        }

        /*
         * Determine if we have all of the fragments.
         *
         * NOTE: at this point, we've placed the data in the
         * fragment table, and the inetgram (igp) has been
         * deleted.
         */
        if (!frag_chk())
            continue;

        newgp = make_trans_datagram(index, NULL, ipsrc, ipdst, iphlen);
        if (newgp == NULL)
            continue;
        add_grams(&ipv4_listp, newgp);
        datagrams++;
    }
    if (ipv4_listp == NULL && fragments != 0) {
        if (++input_attempts > FRAG_ATTEMPTS) {
            dprintf("ipv4_input(%d): reassembly(%d) timed out in "
                "%d msecs.\n", index, fragments,
                sockets[index].in_timeout * input_attempts);
            frag_flush();
            errno = ETIMEDOUT;
            return (-1);
        } else {
            /*
             * Call the media layer again... there may be more
             * packets waiting.
             */
            if (sockets[index].input[MEDIA_LVL](index) < 0) {
                /* errno will be set appropriately */
                frag_flush();
                return (-1);
            }
            goto ipv4_try_again;
        }
    }

    add_grams(&sockets[index].inq, ipv4_listp);

    return (datagrams);
}

/*
 * ipv4_output: Generate IPv4 datagram(s) for the payload and deliver them.
 * Routing is handled here as well, by reusing the saddr field to hold the
 * router's IP address.
 *
 * We don't deal with fragmentation on the outgoing side.
 *
 * Arguments: index to socket, inetgram to send.
 *
 * Returns: 0 for success, -1 if error occurred.
 */
int
ipv4_output(int index, struct inetgram *ogp)
{
    struct ip   *iphp;
    uint64_t    iphbuffer[sizeof (struct ip)];

#ifdef  DEBUG
    printf("ipv4_output(%d): size %d\n", index,
        ogp->igm_mp->b_wptr - ogp->igm_mp->b_rptr);
#endif  /* DEBUG */

    /* we don't deal (yet) with fragmentation. Maybe never will */
    if ((ogp->igm_mp->b_wptr - ogp->igm_mp->b_rptr) > mac_get_mtu()) {
        dprintf("ipv4: datagram too big for MAC layer.\n");
        errno = E2BIG;
        return (-1);
    }

    if (ogp->igm_level != NETWORK_LVL) {
#ifdef  DEBUG
        printf("ipv4_output(%d): unexpected frame type: %d\n", index,
            ogp->igm_level);
#endif  /* DEBUG */
        errno = EINVAL;
        return (-1);
    }

    if (sockets[index].out_flags & SO_DONTROUTE)
        ogp->igm_oflags |= MSG_DONTROUTE;

    iphp = (struct ip *)&iphbuffer;
    iphp->ip_v = IPVERSION;
    iphp->ip_hl = sizeof (struct ip) / 4;
    iphp->ip_tos = 0;
    iphp->ip_len = htons(ogp->igm_mp->b_wptr - ogp->igm_mp->b_rptr +
        sizeof (struct ip));
    iphp->ip_id = htons(++g_ip_id);
    iphp->ip_off = htons(IP_DF);
    iphp->ip_p = sockets[index].proto;
    iphp->ip_sum = htons(0);
    iphp->ip_ttl = ttl;

    /* struct copies */
    iphp->ip_src = myip;
    iphp->ip_dst = ogp->igm_saddr.sin_addr;

    /*
     * On local / limited broadcasts, don't route. From a purist's
     * perspective, we should be setting the TTL to 1. But
     * operational experience has shown that some BOOTP relay agents
     * (ciscos) discard our packets. Furthermore, these devices also
     * *don't* reset the TTL to MAXTTL on the unicast side of the
     * BOOTP relay agent! Sigh. Thus to work correctly in these
     * environments, we leave the TTL as it has been been set by
     * the application layer, and simply don't check for a route.
     */
    if (iphp->ip_dst.s_addr == htonl(INADDR_BROADCAST) ||
        (netmask.s_addr != htonl(INADDR_BROADCAST) &&
        iphp->ip_dst.s_addr == (mynet.s_addr | ~netmask.s_addr))) {
        ogp->igm_oflags |= MSG_DONTROUTE;
    }

    /* Routing necessary? */
    if ((ogp->igm_oflags & MSG_DONTROUTE) == 0 &&
        ((iphp->ip_dst.s_addr & netmask.s_addr) != mynet.s_addr)) {
        struct in_addr *rip;
        if ((rip = ipv4_get_route(RT_HOST, &iphp->ip_dst,
            NULL)) == NULL) {
            rip = ipv4_get_route(RT_DEFAULT, NULL, NULL);
        }
        if (rip == NULL) {
            dprintf("ipv4(%d): No route to %s.\n",
                index, inet_ntoa(iphp->ip_dst));
            errno = EHOSTUNREACH;
            return (-1);
        }
        ogp->igm_router.s_addr = rip->s_addr;
    } else
        ogp->igm_router.s_addr = htonl(INADDR_ANY);

    iphp->ip_sum = ipv4cksum((uint16_t *)iphp, sizeof (struct ip));
    ogp->igm_mp->b_rptr -= sizeof (struct ip);
    bcopy((caddr_t)iphp, (caddr_t)(ogp->igm_mp->b_rptr),
        sizeof (struct ip));

    ogp->igm_level = MEDIA_LVL;

    return (0);
}

/*
 * Function to be called by TCP to send out a packet.  This is used
 * when TCP wants to send out packets which it has already filled in
 * most of the header fields.
 */
int
ipv4_tcp_output(int sock_id, mblk_t *pkt)
{
    struct ip *iph;
    struct in_addr *rip = NULL;
    struct inetgram datagram;

    iph = (struct ip *)pkt->b_rptr;

    bzero(&datagram, sizeof (struct inetgram));

    /*
     * Bootparams doesn't know about subnet masks, so we need to
     * explicitly check for this flag.
     */
    if (sockets[sock_id].out_flags & SO_DONTROUTE)
        datagram.igm_oflags |= MSG_DONTROUTE;

    /* Routing necessary? */
    if (((datagram.igm_oflags & MSG_DONTROUTE) == 0) &&
        ((iph->ip_dst.s_addr & netmask.s_addr) != mynet.s_addr)) {
        if ((rip = ipv4_get_route(RT_HOST, &iph->ip_dst,
            NULL)) == NULL) {
            rip = ipv4_get_route(RT_DEFAULT, NULL, NULL);
        }
        if (rip == NULL) {
            dprintf("ipv4(%d): No route to %s.\n",
                sock_id, inet_ntoa(iph->ip_dst));
            errno = EHOSTUNREACH;
            return (-1);
        }
    }

    iph->ip_id = htons(++g_ip_id);
    iph->ip_sum = ipv4cksum((uint16_t *)iph, sizeof (struct ip));
#if DEBUG > 1
    printf("ipv4_tcp_output: dump IP packet(%d)\n", iph->ip_len);
    hexdump((char *)pkt->b_rptr, iph->ip_len);
#endif
    /* Call the MAC layer output routine to send it out. */
    datagram.igm_mp = pkt;
    datagram.igm_level = MEDIA_LVL;
    if (rip != NULL)
        datagram.igm_router.s_addr = rip->s_addr;
    else
        datagram.igm_router.s_addr = 0;
    return (mac_state.mac_output(sock_id, &datagram));
}

/*
 * Internet address interpretation routine.
 * All the network library routines call this
 * routine to interpret entries in the data bases
 * which are expected to be an address.
 * The value returned is in network order.
 */
in_addr_t
inet_addr(const char *cp)
{
    uint32_t val, base, n;
    char c;
    uint32_t parts[4], *pp = parts;

    if (*cp == '\0')
        return ((uint32_t)-1); /* disallow null string in cp */
again:
    /*
     * Collect number up to ``.''.
     * Values are specified as for C:
     * 0x=hex, 0=octal, other=decimal.
     */
    val = 0; base = 10;
    if (*cp == '0') {
        if (*++cp == 'x' || *cp == 'X')
            base = 16, cp++;
        else
            base = 8;
    }
    while ((c = *cp) != NULL) {
        if (isdigit(c)) {
            if ((c - '0') >= base)
                break;
            val = (val * base) + (c - '0');
            cp++;
            continue;
        }
        if (base == 16 && isxdigit(c)) {
            val = (val << 4) + (c + 10 - (islower(c) ? 'a' : 'A'));
            cp++;
            continue;
        }
        break;
    }
    if (*cp == '.') {
        /*
         * Internet format:
         *  a.b.c.d
         *  a.b.c   (with c treated as 16-bits)
         *  a.b (with b treated as 24 bits)
         */
        if ((pp >= parts + 3) || (val > 0xff)) {
            return ((uint32_t)-1);
        }
        *pp++ = val, cp++;
        goto again;
    }
    /*
     * Check for trailing characters.
     */
    if (*cp && !isspace(*cp)) {
        return ((uint32_t)-1);
    }
    *pp++ = val;
    /*
     * Concoct the address according to
     * the number of parts specified.
     */
    n = pp - parts;
    switch (n) {

    case 1:             /* a -- 32 bits */
        val = parts[0];
        break;

    case 2:             /* a.b -- 8.24 bits */
        if (parts[1] > 0xffffff)
            return ((uint32_t)-1);
        val = (parts[0] << 24) | (parts[1] & 0xffffff);
        break;

    case 3:             /* a.b.c -- 8.8.16 bits */
        if (parts[2] > 0xffff)
            return ((uint32_t)-1);
        val = (parts[0] << 24) | ((parts[1] & 0xff) << 16) |
            (parts[2] & 0xffff);
        break;

    case 4:             /* a.b.c.d -- 8.8.8.8 bits */
        if (parts[3] > 0xff)
            return ((uint32_t)-1);
        val = (parts[0] << 24) | ((parts[1] & 0xff) << 16) |
            ((parts[2] & 0xff) << 8) | (parts[3] & 0xff);
        break;

    default:
        return ((uint32_t)-1);
    }
    val = htonl(val);
    return (val);
}

void
hexdump(char *data, int datalen)
{
    char *p;
    ushort_t *p16 = (ushort_t *)data;
    char *p8 = data;
    int i, left, len;
    int chunk = 16;  /* 16 bytes per line */

    printf("\n");

    for (p = data; p < data + datalen; p += chunk) {
        printf("\t%4d: ", (int)(p - data));
        left = (data + datalen) - p;
        len = MIN(chunk, left);
        for (i = 0; i < (len / 2); i++)
            printf("%04x ", ntohs(*p16++) & 0xffff);
        if (len % 2) {
            printf("%02x   ", *((unsigned char *)p16));
        }
        for (i = 0; i < (chunk - left) / 2; i++)
            printf("     ");

        printf("   ");
        for (i = 0; i < len; i++, p8++)
            printf("%c", isprint(*p8) ? *p8 : '.');
        printf("\n");
    }

    printf("\n");
}