/*
 * 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 (c) 2010, Oracle and/or its affiliates. All rights reserved.
 */

#include <sys/types.h>
#include <sys/systeminfo.h>
#include <sys/scsi/generic/commands.h>
#include <sys/scsi/impl/commands.h>

#include <scsi/libsmp.h>
#include <scsi/libsmp_plugin.h>

#include <dlfcn.h>
#include <link.h>
#include <dirent.h>
#include <string.h>
#include <strings.h>
#include <limits.h>

#include "smp_impl.h"

static boolean_t _libsmp_plugin_dlclose;

/*
 * As part of basic initialization, we always retrieve the REPORT GENERAL
 * data so that we will know whether this target supports the long response
 * format.
 */
static int
smp_report_general(smp_target_t *tp)
{
        smp_action_t *ap;
        smp_report_general_resp_t *rp;
        smp_result_t result;
        size_t len;

        if ((ap = smp_action_alloc(SMP_FUNC_REPORT_GENERAL, tp, 0)) == NULL)
                return (-1);

        if (smp_exec(ap, tp) != 0) {
                smp_action_free(ap);
                return (smp_set_errno(ESMP_REPGEN_FAILED));
        }

        smp_action_get_response(ap, &result, (void **)&rp, &len);

        if (result != SMP_RES_FUNCTION_ACCEPTED || len < 24) {
                smp_action_free(ap);
                return (smp_set_errno(ESMP_REPGEN_FAILED));
        }

        bcopy(rp, &tp->st_repgen, sizeof (tp->st_repgen));

        smp_action_free(ap);

        return (0);
}

static int
smp_report_manufacturer_information(smp_target_t *tp)
{
        smp_action_t *ap;
        smp_report_manufacturer_info_resp_t *rp;
        smp_result_t result;
        size_t len;

        ap = smp_action_alloc(SMP_FUNC_REPORT_MANUFACTURER_INFO, tp, 0);
        if (ap == NULL)
                return (-1);

        if (smp_exec(ap, tp) != 0) {
                smp_action_free(ap);
                return (smp_set_errno(ESMP_REPGEN_FAILED));
        }

        smp_action_get_response(ap, &result, (void **)&rp, &len);

        if (result != SMP_RES_FUNCTION_ACCEPTED ||
            len != sizeof (smp_report_manufacturer_info_resp_t)) {
                smp_action_free(ap);
                return (0);     /* Not supported */
        }

        tp->st_vendor = smp_trim_strdup(rp->srmir_vendor_identification,
            sizeof (rp->srmir_vendor_identification));
        tp->st_product = smp_trim_strdup(rp->srmir_product_identification,
            sizeof (rp->srmir_product_identification));
        tp->st_revision = smp_trim_strdup(rp->srmir_product_revision_level,
            sizeof (rp->srmir_product_revision_level));

        if (rp->srmir_sas_1_1_format) {
                tp->st_component_vendor =
                    smp_trim_strdup(rp->srmir_component_vendor_identification,
                    sizeof (rp->srmir_component_vendor_identification));

                tp->st_component_id = SCSI_READ16(&rp->srmir_component_id);
                tp->st_component_revision = rp->srmir_component_revision_level;
        }

        if (tp->st_vendor == NULL || tp->st_product == NULL ||
            tp->st_revision == NULL ||
            (rp->srmir_sas_1_1_format && tp->st_component_vendor == NULL)) {
                smp_action_free(ap);
                return (smp_set_errno(ESMP_NOMEM));
        }

        smp_action_free(ap);

        return (0);
}

static int
smp_target_fill(smp_target_t *tp)
{
        if (smp_report_general(tp) != 0 ||
            smp_report_manufacturer_information(tp) != 0)
                return (-1);

        return (0);
}

const smp_function_def_t *
smp_get_funcdef(smp_target_t *tp, int fn)
{
        smp_plugin_t *pp;
        const smp_function_def_t *dp;

        for (pp = tp->st_plugin_first; pp != NULL; pp = pp->sp_next) {
                if (pp->sp_functions == NULL)
                        continue;

                for (dp = &pp->sp_functions[0]; dp->sfd_rq_len != NULL; dp++) {
                        if (dp->sfd_function == fn)
                                return (dp);
                }
        }

        (void) smp_error(ESMP_BADFUNC, "failed to find function 0x%x", fn);
        return (NULL);
}

int
smp_plugin_register(smp_plugin_t *pp, int version,
    const smp_plugin_config_t *pcp)
{
        if (version != LIBSMP_PLUGIN_VERSION)
                return (smp_set_errno(ESMP_VERSION));

        pp->sp_functions = pcp->spc_functions;

        return (0);
}

void
smp_plugin_setspecific(smp_plugin_t *pp, void *data)
{
        pp->sp_data = data;
}

void *
smp_plugin_getspecific(smp_plugin_t *pp)
{
        return (pp->sp_data);
}

static void
smp_plugin_cleanstr(char *s)
{
        while (*s != '\0') {
                if (*s == ' ' || *s == '/')
                        *s = '-';
                s++;
        }
}

static void
smp_plugin_destroy(smp_plugin_t *pp)
{
        if (pp->sp_initialized && pp->sp_fini != NULL)
                pp->sp_fini(pp);

        if (_libsmp_plugin_dlclose)
                (void) dlclose(pp->sp_object);

        smp_free(pp);
}

static int
smp_plugin_loadone(smp_target_t *tp, const char *path, uint32_t pass)
{
        smp_plugin_t *pp, **loc;
        void *obj;
        int (*smp_priority)(void);

        if ((obj = dlopen(path, RTLD_PARENT | RTLD_LOCAL | RTLD_LAZY)) == NULL)
                return (0);

        if ((pp = smp_zalloc(sizeof (smp_plugin_t))) == NULL) {
                (void) dlclose(obj);
                return (-1);
        }

        pp->sp_object = obj;
        pp->sp_init = (int (*)())dlsym(obj, "_smp_init");
        pp->sp_fini = (void (*)())dlsym(obj, "_smp_fini");
        pp->sp_target = tp;

        if (pp->sp_init == NULL) {
                smp_plugin_destroy(pp);
                return (0);
        }

        /*
         * Framework modules can establish an explicit prioritying by declaring
         * the '_smp_priority' symbol, which returns an integer used to create
         * an explicit ordering between plugins.
         */
        if ((smp_priority = (int (*)())dlsym(obj, "_smp_priority")) != NULL)
                pp->sp_priority = smp_priority();

        pp->sp_priority |= (uint64_t)pass << 32;

        for (loc = &tp->st_plugin_first; *loc != NULL; loc = &(*loc)->sp_next) {
                if ((*loc)->sp_priority > pp->sp_priority)
                        break;
        }

        if (*loc != NULL)
                (*loc)->sp_prev = pp;
        else
                tp->st_plugin_last = pp;

        pp->sp_next = *loc;
        *loc = pp;

        if (pp->sp_init(pp) != 0)
                return (-1);
        pp->sp_initialized = B_TRUE;

        return (0);
}

static int
smp_plugin_load_dir(smp_target_t *tp, const char *pluginroot)
{
        char path[PATH_MAX];
        DIR *dirp;
        struct dirent64 *dp;
        char *c_vendor, *vendor, *product, *revision;
        char isa[257];

        (void) snprintf(path, sizeof (path), "%s/%s",
            pluginroot, LIBSMP_PLUGIN_FRAMEWORK);

#if defined(_LP64)
        if (sysinfo(SI_ARCHITECTURE_64, isa, sizeof (isa)) < 0)
                isa[0] = '\0';
#else
        isa[0] = '\0';
#endif

        if ((dirp = opendir(path)) != NULL) {
                while ((dp = readdir64(dirp)) != NULL) {
                        if (strcmp(dp->d_name, ".") == 0 ||
                            strcmp(dp->d_name, "..") == 0)
                                continue;

                        (void) snprintf(path, sizeof (path), "%s/%s/%s/%s",
                            pluginroot, LIBSMP_PLUGIN_FRAMEWORK,
                            isa, dp->d_name);

                        if (smp_plugin_loadone(tp, path, 0) != 0) {
                                (void) closedir(dirp);
                                return (-1);
                        }
                }

                (void) closedir(dirp);
        }

        /*
         * Now attempt to load platform-specific plugins.  The framework
         * plugins had better give us the ability to perform basic SMP
         * functions like REPORT GENERAL and REPORT MANUFACTURER INFORMATION;
         * if not, we're toast anyway.  If the latter is not supported, we
         * will not be able to use any vendor-specific plugins.  Note that
         * there are actually two possible specifications for vendor plugins:
         * those matching the vendor/product/revision fields, and those
         * matching the component vendor/id/revision fields.  The component is
         * less specific, so we try to load those first.
         */

        if (smp_target_fill(tp) != 0)
                return (-1);

        if (tp->st_vendor == NULL)
                return (0);

        if (tp->st_component_vendor != NULL) {
                c_vendor = strdupa(tp->st_component_vendor);
                smp_plugin_cleanstr(c_vendor);
        }

        vendor = strdupa(tp->st_vendor);
        product = strdupa(tp->st_product);
        revision = strdupa(tp->st_revision);

        smp_plugin_cleanstr(vendor);
        smp_plugin_cleanstr(product);
        smp_plugin_cleanstr(revision);

        if (tp->st_component_vendor != NULL) {
                (void) snprintf(path, sizeof (path), "%s/%s/%s/component_%s%s",
                    pluginroot, LIBSMP_PLUGIN_VENDOR, isa, c_vendor,
                    LIBSMP_PLUGIN_EXT);
                if (smp_plugin_loadone(tp, path, 1) != 0)
                        return (-1);

                (void) snprintf(path, sizeof (path),
                    "%s/%s/%s/component_%s-%04x%s",
                    pluginroot, LIBSMP_PLUGIN_VENDOR, isa, c_vendor,
                    tp->st_component_id, LIBSMP_PLUGIN_EXT);
                if (smp_plugin_loadone(tp, path, 2) != 0)
                        return (-1);

                (void) snprintf(path, sizeof (path),
                    "%s/%s/%s/component_%s-%04x-%02x%s",
                    pluginroot, LIBSMP_PLUGIN_VENDOR, isa, c_vendor,
                    tp->st_component_id, tp->st_component_revision,
                    LIBSMP_PLUGIN_EXT);
                if (smp_plugin_loadone(tp, path, 3) != 0)
                        return (-1);
        }

        (void) snprintf(path, sizeof (path), "%s/%s/%s/%s%s", pluginroot,
            LIBSMP_PLUGIN_VENDOR, isa, vendor, LIBSMP_PLUGIN_EXT);
        if (smp_plugin_loadone(tp, path, 4) != 0)
                return (-1);

        (void) snprintf(path, sizeof (path), "%s/%s/%s/%s-%s%s", pluginroot,
            LIBSMP_PLUGIN_VENDOR, isa, vendor, product, LIBSMP_PLUGIN_EXT);
        if (smp_plugin_loadone(tp, path, 5) != 0)
                return (-1);

        (void) snprintf(path, sizeof (path), "%s/%s/%s/%s-%s-%s%s", pluginroot,
            LIBSMP_PLUGIN_VENDOR, isa, vendor, product,
            revision, LIBSMP_PLUGIN_EXT);
        if (smp_plugin_loadone(tp, path, 6) != 0)
                return (-1);

        return (0);
}

int
smp_plugin_load(smp_target_t *tp)
{
        char pluginroot[PATH_MAX];
        const char *pluginpath, *p, *q;

        if ((pluginpath = getenv("SMP_PLUGINPATH")) == NULL)
                pluginpath = LIBSMP_DEFAULT_PLUGINDIR;
        _libsmp_plugin_dlclose = (getenv("SMP_NODLCLOSE") == NULL);

        for (p = pluginpath; p != NULL; p = q) {
                if ((q = strchr(p, ':')) != NULL) {
                        ptrdiff_t len = q - p;
                        (void) strncpy(pluginroot, p, len);
                        pluginroot[len] = '\0';
                        while (*q == ':')
                                ++q;
                        if (*q == '\0')
                                q = NULL;
                        if (len == 0)
                                continue;
                } else {
                        (void) strcpy(pluginroot, p);
                }

                if (pluginroot[0] != '/')
                        continue;

                if (smp_plugin_load_dir(tp, pluginroot) != 0)
                        return (-1);
        }

        if (tp->st_plugin_first == NULL)
                return (smp_error(ESMP_PLUGIN, "no plugins found"));

        return (0);
}

void
smp_plugin_unload(smp_target_t *tp)
{
        smp_plugin_t *pp;

        while ((pp = tp->st_plugin_first) != NULL) {
                tp->st_plugin_first = pp->sp_next;
                smp_plugin_destroy(pp);
        }
}