/*
 * 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 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <sys/types.h>
#include <sys/stream.h>
#include <sys/strsun.h>
#include <sys/sunddi.h>
#include <sys/kstat.h>
#include <sys/kmem.h>
#include <sys/sdt.h>
#include <net/pfkeyv2.h>
#include <inet/common.h>
#include <inet/ip.h>
#include <inet/ip6.h>
#include <inet/ipsec_impl.h>
#include <inet/ipdrop.h>

/*
 * Packet drop facility.
 */

/*
 * Initialize drop facility kstats.
 */
void
ip_drop_init(ipsec_stack_t *ipss)
{
        ipss->ipsec_ip_drop_kstat = kstat_create_netstack("ip", 0, "ipdrop",
            "net", KSTAT_TYPE_NAMED,
            sizeof (struct ip_dropstats) / sizeof (kstat_named_t),
            KSTAT_FLAG_PERSISTENT, ipss->ipsec_netstack->netstack_stackid);

        if (ipss->ipsec_ip_drop_kstat == NULL ||
            ipss->ipsec_ip_drop_kstat->ks_data == NULL)
                return;

        /*
         * Note: here ipss->ipsec_ip_drop_types is initialized, however,
         * if the previous kstat_create_netstack failed, it will remain
         * NULL. Note this is done for all stack instances, so it *could*
         * be NULL. Hence a non-NULL checking is added where
         * ipss->ipsec_ip_drop_types is used. This checking is hidden in
         * the DROPPER macro.
         */
        ipss->ipsec_ip_drop_types = ipss->ipsec_ip_drop_kstat->ks_data;

        /* TCP IPsec drop statistics. */
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_tcp_clear,
            "tcp_clear", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_tcp_secure,
            "tcp_secure", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_tcp_mismatch,
            "tcp_mismatch", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_tcp_ipsec_alloc,
            "tcp_ipsec_alloc", KSTAT_DATA_UINT64);

        /* SADB-specific drop statistics. */
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_sadb_inlarval_timeout,
            "sadb_inlarval_timeout", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_sadb_inlarval_replace,
            "sadb_inlarval_replace", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_sadb_inidle_overflow,
            "sadb_inidle_overflow", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_sadb_inidle_timeout,
            "sadb_inidle_timeout", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_sadb_acquire_nomem,
            "sadb_acquire_nomem", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_sadb_acquire_toofull,
            "sadb_acquire_toofull", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_sadb_acquire_timeout,
            "sadb_acquire_timeout", KSTAT_DATA_UINT64);

        /* SPD drop statistics. */
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_spd_ahesp_diffid,
            "spd_ahesp_diffid", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_spd_loopback_mismatch,
            "spd_loopback_mismatch", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_spd_explicit,
            "spd_explicit", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_spd_got_secure,
            "spd_got_secure", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_spd_got_clear,
            "spd_got_clear", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_spd_bad_ahalg,
            "spd_bad_ahalg", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_spd_got_ah,
            "spd_got_ah", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_spd_bad_espealg,
            "spd_bad_espealg", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_spd_bad_espaalg,
            "spd_bad_espaalg", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_spd_got_esp,
            "spd_got_esp", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_spd_got_selfencap,
            "spd_got_selfencap", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_spd_bad_selfencap,
            "spd_bad_selfencap", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_spd_nomem,
            "spd_nomem", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_spd_ah_badid,
            "spd_ah_badid", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_spd_ah_innermismatch,
            "spd_ah_innermismatch", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_spd_esp_innermismatch,
            "spd_esp_innermismatch", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_spd_esp_badid,
            "spd_esp_badid", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_spd_no_policy,
            "spd_no_policy", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_spd_malformed_packet,
            "spd_malformed_packet", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_spd_malformed_frag,
            "spd_malformed_frag", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_spd_overlap_frag,
            "spd_overlap_frag", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_spd_evil_frag,
            "spd_evil_frag", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_spd_max_frags,
            "spd_max_frags", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_spd_expired_frags,
            "spd_expired_frags", KSTAT_DATA_UINT64);

        /* ESP-specific drop statistics. */

        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_esp_nomem,
            "esp_nomem", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_esp_no_sa,
            "esp_no_sa", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_esp_early_replay,
            "esp_early_replay", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_esp_replay,
            "esp_replay", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_esp_bytes_expire,
            "esp_bytes_expire", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_esp_bad_padlen,
            "esp_bad_padlen", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_esp_bad_padding,
            "esp_bad_padding", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_esp_bad_auth,
            "esp_bad_auth", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_esp_crypto_failed,
            "esp_crypto_failed", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_esp_icmp,
            "esp_icmp", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_esp_nat_t_ipsec,
            "esp_nat_t_ipsec", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_esp_nat_t_ka,
            "esp_nat_t_ka", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_esp_iv_wrap,
            "esp_iv_wrap", KSTAT_DATA_UINT64);

        /* AH-specific drop statistics. */
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_ah_nomem,
            "ah_nomem", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_ah_bad_v6_hdrs,
            "ah_bad_v6_hdrs", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_ah_bad_v4_opts,
            "ah_bad_v4_opts", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_ah_no_sa,
            "ah_no_sa", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_ah_bad_length,
            "ah_bad_length", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_ah_bad_auth,
            "ah_bad_auth", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_ah_crypto_failed,
            "ah_crypto_failed", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_ah_early_replay,
            "ah_early_replay", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_ah_replay,
            "ah_replay", KSTAT_DATA_UINT64);
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_ah_bytes_expire,
            "ah_bytes_expire", KSTAT_DATA_UINT64);

        /* IP-specific drop statistics. */
        kstat_named_init(&ipss->ipsec_ip_drop_types->ipds_ip_ipsec_not_loaded,
            "ip_ipsec_not_loaded", KSTAT_DATA_UINT64);

        kstat_install(ipss->ipsec_ip_drop_kstat);
}

void
ip_drop_destroy(ipsec_stack_t *ipss)
{
        kstat_delete_netstack(ipss->ipsec_ip_drop_kstat,
            ipss->ipsec_netstack->netstack_stackid);
        ipss->ipsec_ip_drop_kstat = NULL;
        ipss->ipsec_ip_drop_types = NULL;
}

/*
 * Register a packet dropper.
 */
void
ip_drop_register(ipdropper_t *ipd, char *name)
{
        if (ipd->ipd_name != NULL) {
                cmn_err(CE_WARN,
                    "ip_drop_register: ipdropper %s already registered with %s",
                    name, ipd->ipd_name);
                return;
        }

        /* Assume that name is reasonable in length.  This isn't user-land. */
        ipd->ipd_name = kmem_alloc(strlen(name) + 1, KM_SLEEP);
        (void) strcpy(ipd->ipd_name, name);
}

/*
 * Un-register a packet dropper.
 */
void
ip_drop_unregister(ipdropper_t *ipd)
{
        if (ipd->ipd_name == NULL) {
                cmn_err(CE_WARN,
                    "ip_drop_unregister: not registered (%p)\n",
                    (void *)ipd);
                return;
        }
        kmem_free(ipd->ipd_name, strlen(ipd->ipd_name) + 1);

        ipd->ipd_name = NULL;
}

/*
 * Actually drop a packet.  Many things could happen here, but at the least,
 * the packet will be freemsg()ed.
 */
void
ip_drop_packet(mblk_t *mp, boolean_t inbound, ill_t *ill,
    struct kstat_named *counter, ipdropper_t *who_called)
{
        char *str;

        if (mp == NULL) {
                /*
                 * Return immediately - NULL packets should not affect any
                 * statistics.
                 */
                return;
        }

        ASSERT(mp->b_datap->db_type == M_DATA);

        /* Increment the bean counter, if available. */
        if (counter != NULL) {
                switch (counter->data_type) {
                case KSTAT_DATA_INT32:
                        counter->value.i32++;
                        break;
                case KSTAT_DATA_UINT32:
                        counter->value.ui32++;
                        break;
                case KSTAT_DATA_INT64:
                        counter->value.i64++;
                        break;
                case KSTAT_DATA_UINT64:
                        counter->value.ui64++;
                        break;
                /* Other types we can't handle for now. */
                }
        }

        if (counter != NULL)
                str = counter->name;
        else if (who_called != NULL)
                str = who_called->ipd_name;
        else
                str = "Unspecified IPsec drop";

        if (inbound)
                ip_drop_input(str, mp, ill);
        else
                ip_drop_output(str, mp, ill);

        /* TODO: queue the packet onto a snoop-friendly queue. */

        /*
         * ASSERT this isn't a b_next linked mblk chain where a
         * chained dropper should be used instead
         */
        ASSERT(mp->b_prev == NULL && mp->b_next == NULL);
        freemsg(mp);
}

/*
 * This is just a convinient place for dtrace to see dropped packets
 */
/*ARGSUSED*/
void
ip_drop_input(char *str, mblk_t *mp, ill_t *ill)
{
        if (mp == NULL)
                return;

        if (IPH_HDR_VERSION(mp->b_rptr) == IPV4_VERSION) {
                ipha_t *ipha = (ipha_t *)mp->b_rptr;

                DTRACE_IP7(drop__in, mblk_t *, mp, conn_t *, NULL, void_ip_t *,
                    ipha, __dtrace_ipsr_ill_t *, ill, ipha_t *, ipha,
                    ip6_t *, NULL, int, 0);
        } else {
                ip6_t *ip6h = (ip6_t *)mp->b_rptr;

                DTRACE_IP7(drop__in, mblk_t *, mp, conn_t *, NULL, void_ip_t *,
                    ip6h, __dtrace_ipsr_ill_t *, ill, ipha_t *, NULL,
                    ip6_t *, ip6h, int, 0);
        }
}

/*ARGSUSED*/
void
ip_drop_output(char *str, mblk_t *mp, ill_t *ill)
{
        if (mp == NULL)
                return;

        if (IPH_HDR_VERSION(mp->b_rptr) == IPV4_VERSION) {
                ipha_t *ipha = (ipha_t *)mp->b_rptr;

                DTRACE_IP7(drop__out, mblk_t *, mp, conn_t *, NULL, void_ip_t *,
                    ipha, __dtrace_ipsr_ill_t *, ill, ipha_t *, ipha,
                    ip6_t *, NULL, int, 0);
        } else {
                ip6_t *ip6h = (ip6_t *)mp->b_rptr;

                DTRACE_IP7(drop__out, mblk_t *, mp, conn_t *, NULL, void_ip_t *,
                    ip6h, __dtrace_ipsr_ill_t *, ill, ipha_t *, NULL,
                    ip6_t *, ip6h, int, 0);
        }
}