/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (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 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 *
 * ipv4.c, Code implementing the IPv4 internet protocol.
 */

#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;
                }
                break;
        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 if (IN_CLASSC(ntohl(myip.s_addr)))
                        ip->s_addr = ntohl(IN_CLASSC_NET);
                else
                        ip->s_addr = ntohl(IN_CLASSE_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) != '\0') {
                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");
}