/*
 * 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.
 */

/*
 * bridged - bridging control daemon.  This module provides functions related
 * to the librstp (Rapid Spanning Tree Protocol) library.
 */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdarg.h>
#include <string.h>
#include <sys/types.h>
#include <syslog.h>
#include <kstat.h>
#include <libdlpi.h>
#include <libdladm.h>
#include <libdllink.h>
#include <libdlstat.h>
#include <stp_in.h>
#include <stp_vectors.h>
#include <net/if_types.h>
#include <net/bridge.h>
#include <sys/ethernet.h>

#include "global.h"

/* current engine configuration; access protected by engine_lock */
static UID_STP_CFG_T uid_cfg;

/*
 * Our implementation doesn't have per-VLAN forwarding entries, so we just
 * flush by the port.  If port number is zero, then flush entries.
 */
/*ARGSUSED1*/
static int
flush_lt(int port_index, int vlan_id, LT_FLASH_TYPE_T type, char *reason)
{
        struct portdata *pd;
        const char *portname;
        bridge_flushfwd_t bff;

        if (port_index > nextport || port_index < 0)
                return (0);

        if (port_index == 0) {
                type = LT_FLASH_ONLY_THE_PORT;
                portname = "all";
                bff.bff_linkid = DATALINK_INVALID_LINKID;
        } else {
                pd = allports[port_index - 1];
                portname = pd->name;
                bff.bff_linkid = pd->linkid;
        }

        if (debugging) {
                syslog(LOG_DEBUG, "flush forwarding %s %s: %s",
                    type == LT_FLASH_ONLY_THE_PORT ? "to" : "except for",
                    portname, reason);
        }

        bff.bff_exclude = (type == LT_FLASH_ALL_PORTS_EXCLUDE_THIS);

        /*
         * If flushing fails, we can't return.  The only safe thing to do is to
         * tear down the bridge so that we're not harming the network.
         */
        if (strioctl(control_fd, BRIOC_FLUSHFWD, &bff, sizeof (bff)) == -1) {
                syslog(LOG_ERR, "cannot flush forwarding entries on %s %s: %m",
                    instance_name, portname);
                unlock_engine();
                exit(EXIT_FAILURE);
        }

        return (0);
}

static void
get_port_mac(int port_index, unsigned char *mac)
{
        struct portdata *pd;

        if (port_index > nextport || port_index <= 0)
                return;

        pd = allports[port_index - 1];
        (void) memcpy(mac, pd->mac_addr, ETHERADDRL);
}

/* Returns speed in megabits per second */
static unsigned long
get_port_oper_speed(unsigned int port_index)
{
        if (port_index > nextport || port_index == 0)
                return (1000UL);
        else
                return (allports[port_index - 1]->speed);
}

static int
get_port_link_status(int port_index)
{
        struct portdata *pd;

        if (port_index > nextport || port_index <= 0) {
                return (0);
        } else {
                pd = allports[port_index - 1];
                return (pd->phys_status && pd->admin_status &&
                    protect == DLADM_BRIDGE_PROT_STP && !pd->sdu_failed ?
                    1 : 0);
        }
}

static int
get_duplex(int port_index)
{
        struct portdata *pd;
        link_duplex_t link_duplex;
        dladm_status_t status;

        if (port_index > nextport || port_index <= 0)
                return (False);

        pd = allports[port_index - 1];
        status = dladm_get_single_mac_stat(dlhandle, pd->linkid, "link_duplex",
            KSTAT_DATA_UINT32, &link_duplex);

        if (status == DLADM_STATUS_OK && link_duplex == LINK_DUPLEX_FULL)
                return (True);
        else
                return (False);
}

static const char *
bls_state(bridge_state_t bstate)
{
        switch (bstate) {
        case BLS_LEARNING:
                return ("learning");
        case BLS_FORWARDING:
                return ("forwarding");
        default:
                return ("block/listen");
        }
}

/*ARGSUSED1*/
static int
set_port_state(int port_index, int vlan_id, RSTP_PORT_STATE state)
{
        struct portdata *pd;
        bridge_setstate_t bss;

        if (port_index > nextport || port_index <= 0)
                return (1);

        pd = allports[port_index - 1];

        if (debugging)
                syslog(LOG_DEBUG, "setting port state on port %d (%s) to %d",
                    port_index, pd->name, state);
        switch (state) {
        case UID_PORT_LEARNING:
                bss.bss_state = BLS_LEARNING;
                break;
        case UID_PORT_FORWARDING:
                bss.bss_state = BLS_FORWARDING;
                break;
        default:
                bss.bss_state = BLS_BLOCKLISTEN;
                break;
        }
        bss.bss_linkid = pd->linkid;
        if (strioctl(control_fd, BRIOC_SETSTATE, &bss, sizeof (bss)) == -1) {
                syslog(LOG_ERR, "cannot set STP state on %s from %s to %s: %m",
                    pd->name, bls_state(pd->state), bls_state(bss.bss_state));
                /*
                 * If we've been unsuccessful in disabling forwarding, then the
                 * only safe thing to do is to make the daemon exit, so that
                 * the kernel will be forced to destroy the bridge state and
                 * terminate all forwarding.
                 */
                if (pd->state == BLS_FORWARDING &&
                    bss.bss_state != BLS_FORWARDING) {
                        unlock_engine();
                        exit(EXIT_FAILURE);
                }
        } else {
                pd->state = bss.bss_state;
        }
        return (0);
}

/*
 * Our hardware doesn't actually do anything different when STP is enabled or
 * disabled, so this function does nothing.  It would be possible to open and
 * close the DLPI stream here, if such a thing were necessary.
 */
static int
set_hardware_mode(int vlan_id, UID_STP_MODE_T mode)
{
        if (debugging)
                syslog(LOG_DEBUG, "setting hardware mode on vlan %d to %d",
                    vlan_id, mode);
        return (0);
}

/*ARGSUSED1*/
static int
tx_bpdu(int port_index, int vlan_id, unsigned char *bpdu, size_t bpdu_len)
{
        struct portdata *pdp;
        int rc;

        if (port_index > nextport || port_index <= 0)
                return (1);

        pdp = allports[port_index - 1];
        rc = dlpi_send(pdp->dlpi, NULL, 0, bpdu, bpdu_len, NULL);
        if (rc == DLPI_SUCCESS) {
                if (debugging)
                        syslog(LOG_DEBUG, "transmitted %d byte BPDU on %s",
                            bpdu_len, pdp->name);
                return (0);
        } else {
                syslog(LOG_WARNING, "failed to send to %s: %s", pdp->name,
                    dlpi_strerror(rc));
                return (1);
        }
}

static const char *
get_port_name(int port_index)
{
        if (port_index > nextport || port_index <= 0)
                return ("unknown");
        else
                return (allports[port_index - 1]->name);
}

/*ARGSUSED*/
static int
get_init_stpm_cfg(int vlan_id, UID_STP_CFG_T *cfg)
{
        /* under engine_lock because it's a callback from the engine */
        *cfg = uid_cfg;
        return (0);
}

/*ARGSUSED*/
static int
get_init_port_cfg(int vlan_id, int port_index, UID_STP_PORT_CFG_T *cfg)
{
        struct portdata *pdp;
        uint_t propval, valcnt;
        datalink_id_t linkid;
        dladm_status_t status;

        if (port_index > nextport || port_index <= 0)
                return (1);

        pdp = allports[port_index - 1];

        cfg->field_mask = 0;
        cfg->port_priority = DEF_PORT_PRIO;
        cfg->admin_non_stp = DEF_ADMIN_NON_STP;
        cfg->admin_edge = DEF_ADMIN_EDGE;
        cfg->admin_port_path_cost = ADMIN_PORT_PATH_COST_AUTO;
        cfg->admin_point2point = DEF_P2P;

        valcnt = 1;
        linkid = pdp->linkid;
        status = dladm_get_linkprop_values(dlhandle, linkid,
            DLADM_PROP_VAL_PERSISTENT, "stp_priority", &propval, &valcnt);
        if (status == DLADM_STATUS_OK) {
                cfg->port_priority = propval;
                cfg->field_mask |= PT_CFG_PRIO;
        }
        status = dladm_get_linkprop_values(dlhandle, linkid,
            DLADM_PROP_VAL_PERSISTENT, "stp", &propval, &valcnt);
        if (status == DLADM_STATUS_OK) {
                cfg->admin_non_stp = !propval;
                cfg->field_mask |= PT_CFG_NON_STP;
        }
        status = dladm_get_linkprop_values(dlhandle, linkid,
            DLADM_PROP_VAL_PERSISTENT, "stp_edge", &propval, &valcnt);
        if (status == DLADM_STATUS_OK) {
                cfg->admin_edge = propval;
                cfg->field_mask |= PT_CFG_EDGE;
        }
        status = dladm_get_linkprop_values(dlhandle, linkid,
            DLADM_PROP_VAL_PERSISTENT, "stp_cost", &propval, &valcnt);
        if (status == DLADM_STATUS_OK) {
                cfg->admin_port_path_cost = propval;
                cfg->field_mask |= PT_CFG_COST;
        }
        status = dladm_get_linkprop_values(dlhandle, linkid,
            DLADM_PROP_VAL_PERSISTENT, "stp_p2p", &propval, &valcnt);
        if (status == DLADM_STATUS_OK) {
                cfg->admin_point2point = propval;
                cfg->field_mask |= PT_CFG_P2P;
        }

        /*
         * mcheck is special.  It is actually a command, but the 802 documents
         * define it as a variable that spontaneously resets itself.  We need
         * to handle that behavior here.
         */
        status = dladm_get_linkprop_values(dlhandle, linkid,
            DLADM_PROP_VAL_PERSISTENT, "stp_mcheck", &propval, &valcnt);
        if (status == DLADM_STATUS_OK && propval != 0) {
                char *pval = "0";

                cfg->field_mask |= PT_CFG_MCHECK;
                (void) dladm_set_linkprop(dlhandle, linkid, "stp_mcheck", &pval,
                    1, DLADM_OPT_ACTIVE|DLADM_OPT_PERSIST|DLADM_OPT_NOREFRESH);
        }

        pdp->admin_non_stp = cfg->admin_non_stp;
        if (!pdp->admin_non_stp)
                pdp->bpdu_protect = B_FALSE;

        return (0);
}

static void
trace(const char *fmt, ...)
{
        va_list ap;

        va_start(ap, fmt);
        vsyslog(LOG_DEBUG, fmt, ap);
        va_end(ap);
}

static STP_VECTORS_T stp_vectors = {
        flush_lt,
        get_port_mac,
        get_port_oper_speed,
        get_port_link_status,
        get_duplex,
        set_port_state,
        set_hardware_mode,
        tx_bpdu,
        get_port_name,
        get_init_stpm_cfg,
        get_init_port_cfg,
        trace
};

void
rstp_init(void)
{
        dladm_status_t status;
        char buf[DLADM_STRSIZE];

        STP_IN_init(&stp_vectors);
        status = dladm_bridge_get_properties(instance_name, &uid_cfg, &protect);
        if (status != DLADM_STATUS_OK) {
                syslog(LOG_ERR, "%s: unable to read properties: %s",
                    instance_name, dladm_status2str(status, buf));
                exit(EXIT_FAILURE);
        }
}

/*
 * This is called by a normal refresh operation.  It gets the engine properties
 * and resets.
 */
void
rstp_refresh(void)
{
        dladm_status_t status;
        int rc;
        char buf[DLADM_STRSIZE];
        UID_STP_CFG_T new_cfg;
        dladm_bridge_prot_t new_prot;

        status = dladm_bridge_get_properties(instance_name, &new_cfg,
            &new_prot);
        if (status != DLADM_STATUS_OK) {
                syslog(LOG_ERR, "%s: unable to refresh bridge properties: %s",
                    instance_name, dladm_status2str(status, buf));
        } else {
                if (debugging && (protect != new_prot ||
                    uid_cfg.stp_enabled != new_cfg.stp_enabled)) {
                        syslog(LOG_DEBUG, "loop protection %s->%s, STP %d->%d",
                            dladm_bridge_prot2str(protect),
                            dladm_bridge_prot2str(new_prot),
                            uid_cfg.stp_enabled, new_cfg.stp_enabled);
                }

                /*
                 * The engine doesn't take kindly to parameter changes while
                 * running.  Disable first if we must do this.
                 */
                if (uid_cfg.stp_enabled &&
                    memcmp(&uid_cfg, &new_cfg, sizeof (uid_cfg)) != 0) {
                        syslog(LOG_DEBUG, "resetting state machine");
                        uid_cfg.stp_enabled = STP_DISABLED;
                        rc = STP_IN_stpm_set_cfg(0, &uid_cfg);
                        if (rc != 0)
                                syslog(LOG_ERR, "STP machine reset config: %s",
                                    STP_IN_get_error_explanation(rc));
                }

                uid_cfg = new_cfg;
                protect = new_prot;
                rc = STP_IN_stpm_set_cfg(0, &uid_cfg);
                if (rc != 0)
                        syslog(LOG_ERR, "STP machine set config: %s",
                            STP_IN_get_error_explanation(rc));
        }
}

/*
 * This is called when a port changes its MAC address.  If it's the main port,
 * the one that supplies us our bridge ID, then we must choose a new ID, and to
 * do that we shut the bridge down and bring it back up.
 */
void
rstp_change_mac(struct portdata *port, const unsigned char *newaddr)
{
        unsigned short prio;
        unsigned char mac[ETHERADDRL];
        int rc;
        char curid[ETHERADDRL * 3];
        char newmac[ETHERADDRL * 3];

        (void) _link_ntoa(port->mac_addr, curid, ETHERADDRL, IFT_OTHER);
        (void) _link_ntoa(newaddr, newmac, ETHERADDRL, IFT_OTHER);
        STP_IN_get_bridge_id(port->vlan_id, &prio, mac);
        if (memcmp(port->mac_addr, mac, ETHERADDRL) == 0) {
                syslog(LOG_NOTICE, "bridge ID must change: ID %s on %s changed "
                    "to %s", curid, port->name, newmac);
                uid_cfg.stp_enabled = STP_DISABLED;
                if ((rc = STP_IN_stpm_set_cfg(0, &uid_cfg)) != 0)
                        syslog(LOG_ERR, "STP machine set config: %s",
                            STP_IN_get_error_explanation(rc));
                (void) memcpy(port->mac_addr, newaddr, ETHERADDRL);
                uid_cfg.stp_enabled = STP_ENABLED;
                if ((rc = STP_IN_stpm_set_cfg(0, &uid_cfg)) != 0)
                        syslog(LOG_ERR, "STP machine set config: %s",
                            STP_IN_get_error_explanation(rc));
        } else {
                syslog(LOG_DEBUG,
                    "MAC address on %s changed from %s to %s", port->name,
                    curid, newmac);
                (void) memcpy(port->mac_addr, newaddr, ETHERADDRL);
        }
}

boolean_t
rstp_add_port(struct portdata *port)
{
        int rc;
        UID_STP_PORT_CFG_T portcfg;
        bridge_vlanenab_t bve;
        bridge_setstate_t bss;

        if (!port->stp_added &&
            (rc = STP_IN_port_add(port->vlan_id, port->port_index)) != 0) {
                syslog(LOG_ERR, "STP add %s %d: %s", port->name,
                    port->port_index, STP_IN_get_error_explanation(rc));
                return (B_FALSE);
        }
        port->stp_added = B_TRUE;

        /* guaranteed to succeed at this point */
        (void) get_init_port_cfg(port->vlan_id, port->port_index, &portcfg);

        /*
         * Restore state when reenabling STP engine, set fixed state when
         * disabling.  For TRILL, we don't control forwarding at all, but we
         * need to turn off our controls for TRILL to do its thing.
         */
        bss.bss_linkid = port->linkid;
        if (protect != DLADM_BRIDGE_PROT_STP) {
                bss.bss_state = port->state = BLS_BLOCKLISTEN;
        } else if (portcfg.admin_non_stp) {
                bss.bss_state = port->admin_status && !port->sdu_failed &&
                    !port->bpdu_protect ? BLS_FORWARDING : BLS_BLOCKLISTEN;
        } else {
                bss.bss_state = port->state;
        }
        if (strioctl(control_fd, BRIOC_SETSTATE, &bss, sizeof (bss)) == -1) {
                syslog(LOG_ERR, "cannot set STP state on %s: %m", port->name);
                goto failure;
        }

        rc = STP_IN_enable_port(port->port_index,
            port->admin_status && port->phys_status && !port->sdu_failed &&
            protect == DLADM_BRIDGE_PROT_STP);
        if (rc != 0) {
                syslog(LOG_ERR, "STP enable %s %d: %s", port->name,
                    port->port_index, STP_IN_get_error_explanation(rc));
                goto failure;
        }

        if (debugging) {
                rc = STP_IN_dbg_set_port_trace("all", True, 0,
                    port->port_index);
        } else {
                /* return to default debug state */
                rc = STP_IN_dbg_set_port_trace("all", False, 0,
                    port->port_index);
                if (rc == 0)
                        rc = STP_IN_dbg_set_port_trace("sttrans", True, 0,
                            port->port_index);
        }
        if (rc != 0) {
                syslog(LOG_ERR, "STP trace %s %d: %s", port->name,
                    port->port_index, STP_IN_get_error_explanation(rc));
                goto failure;
        }

        /* Clear out the kernel's allowed VLAN set; second walk will set */
        bve.bve_linkid = port->linkid;
        bve.bve_vlan = 0;
        bve.bve_onoff = B_FALSE;
        if (strioctl(control_fd, BRIOC_VLANENAB, &bve, sizeof (bve)) == -1) {
                syslog(LOG_ERR, "unable to disable VLANs on %s: %m",
                    port->name);
                goto failure;
        }

        if ((rc = STP_IN_port_set_cfg(0, port->port_index, &portcfg)) != 0) {
                syslog(LOG_ERR, "STP port configure %s %d: %s", port->name,
                    port->port_index, STP_IN_get_error_explanation(rc));
                goto failure;
        }

        return (B_TRUE);

failure:
        (void) STP_IN_port_remove(port->vlan_id, port->port_index);
        port->stp_added = B_FALSE;
        return (B_FALSE);
}