/*
 * 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) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
 */
/*
 * Copyright 2012 Nexenta Systems, Inc.  All rights reserved.
 */

#include <scsi/libses.h>
#include "ses_impl.h"

static boolean_t ses_plugin_dlclose;

/*ARGSUSED*/
void *
ses_plugin_ctlpage_lookup(ses_plugin_t *sp, ses_snap_t *snap, int pagenum,
    size_t len, ses_node_t *np, boolean_t unique)
{
        ses_target_t *tp = snap->ss_target;
        ses_snap_page_t *pp;
        ses_pagedesc_t *dp;

        if ((pp = ses_snap_ctl_page(snap, pagenum, len, unique)) == NULL)
                return (NULL);

        if ((dp = ses_get_pagedesc(tp, pagenum, SES_PAGE_CTL)) == NULL)
                return (NULL);

        if (np != NULL && dp->spd_ctl_fill != NULL) {
                return (dp->spd_ctl_fill(sp, pp->ssp_page,
                    pp->ssp_len, np));
        } else {
                return (pp->ssp_page);
        }
}

int
ses_fill_node(ses_node_t *np)
{
        ses_target_t *tp = np->sn_snapshot->ss_target;
        ses_plugin_t *sp;

        for (sp = tp->st_plugin_first; sp != NULL; sp = sp->sp_next) {
                if (sp->sp_node_parse == NULL)
                        continue;

                if (sp->sp_node_parse(sp, np) != 0)
                        return (-1);
        }

        return (0);
}

int
ses_node_ctl(ses_node_t *np, const char *op, nvlist_t *arg)
{
        ses_target_t *tp = np->sn_snapshot->ss_target;
        ses_plugin_t *sp;
        nvlist_t *nvl;
        nvpair_t *nvp;
        int ret;

        if (nvlist_dup(arg, &nvl, 0) != 0)
                return (ses_set_errno(ESES_NOMEM));

        /*
         * Technically we could get away with a per-snapshot lock while we fill
         * the control page contents, but this doesn't take much time and we
         * want actual control operations to be protected per-target, so we just
         * take the target lock.
         */
        (void) pthread_mutex_lock(&tp->st_lock);

        /*
         * We walk the list of plugins backwards, so that a product-specific
         * plugin can rewrite the nvlist to control operations in terms of the
         * standard mechanisms, if desired.
         */
        for (sp = tp->st_plugin_first; sp != NULL; sp = sp->sp_next) {
                if (sp->sp_node_ctl == NULL)
                        continue;

                if (sp->sp_node_ctl(sp, np, op, nvl) != 0) {
                        nvlist_free(nvl);
                        (void) pthread_mutex_unlock(&tp->st_lock);
                        return (-1);
                }
        }

        if ((nvp = nvlist_next_nvpair(nvl, NULL)) != NULL) {
                (void) ses_error(ESES_NOTSUP, "property '%s' invalid for "
                    "this node", nvpair_name(nvp));
                nvlist_free(nvl);
                (void) pthread_mutex_unlock(&tp->st_lock);
                return (-1);
        }

        nvlist_free(nvl);

        ret = ses_snap_do_ctl(np->sn_snapshot);
        (void) pthread_mutex_unlock(&tp->st_lock);

        return (ret);
}

/*ARGSUSED*/
void *
ses_plugin_page_lookup(ses_plugin_t *sp, ses_snap_t *snap, int pagenum,
    ses_node_t *np, size_t *lenp)
{
        ses_snap_page_t *pp;
        ses_target_t *tp = sp->sp_target;
        ses_pagedesc_t *dp;

        if ((dp = ses_get_pagedesc(tp, pagenum, SES_PAGE_DIAG)) == NULL)
                return (NULL);

        if ((pp = ses_snap_find_page(snap, pagenum, B_FALSE)) == NULL)
                return (NULL);

        if (np != NULL && dp->spd_index != NULL) {
                return (dp->spd_index(sp, np, pp->ssp_page, pp->ssp_len,
                    lenp));
        } else {
                *lenp = pp->ssp_len;
                return (pp->ssp_page);
        }
}

ses_pagedesc_t *
ses_get_pagedesc(ses_target_t *tp, int pagenum, ses_pagetype_t type)
{
        ses_plugin_t *sp;
        ses_pagedesc_t *dp;

        for (sp = tp->st_plugin_first; sp != NULL; sp = sp->sp_next) {
                if (sp->sp_pages == NULL)
                        continue;

                for (dp = &sp->sp_pages[0]; dp->spd_pagenum != -1;
                    dp++) {
                        if ((type == SES_PAGE_CTL && dp->spd_ctl_len == NULL) ||
                            (type == SES_PAGE_DIAG && dp->spd_ctl_len != NULL))
                                continue;

                        if (dp->spd_pagenum == pagenum)
                                return (dp);
                }
        }

        (void) ses_error(ESES_BAD_PAGE, "failed to find page 0x%x", pagenum);
        return (NULL);
}

int
ses_plugin_register(ses_plugin_t *sp, int version, ses_plugin_config_t *scp)
{
        if (version != LIBSES_PLUGIN_VERSION)
                return (ses_set_errno(ESES_VERSION));

        sp->sp_pages = scp->spc_pages;
        sp->sp_node_parse = scp->spc_node_parse;
        sp->sp_node_ctl = scp->spc_node_ctl;

        return (0);
}

void
ses_plugin_setspecific(ses_plugin_t *sp, void *data)
{
        sp->sp_data = data;
}

void *
ses_plugin_getspecific(ses_plugin_t *sp)
{
        return (sp->sp_data);
}

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

static void
ses_plugin_destroy(ses_plugin_t *sp)
{
        if (sp->sp_initialized && sp->sp_fini != NULL)
                sp->sp_fini(sp);

        if (ses_plugin_dlclose)
                (void) dlclose(sp->sp_object);

        ses_free(sp);
}

static int
ses_plugin_loadone(ses_target_t *tp, const char *path, uint32_t pass)
{
        ses_plugin_t *sp, **loc;
        void *obj;
        int (*ses_priority)(void);

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

        if ((sp = ses_zalloc(sizeof (ses_plugin_t))) == NULL) {
                (void) dlclose(obj);
                return (-1);
        }

        sp->sp_object = obj;
        sp->sp_init = (int (*)())dlsym(obj, "_ses_init");
        sp->sp_fini = (void (*)())dlsym(obj, "_ses_fini");
        sp->sp_target = tp;

        if (sp->sp_init == NULL) {
                ses_plugin_destroy(sp);
                return (0);
        }

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

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

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

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

        sp->sp_next = *loc;
        *loc = sp;

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

        return (0);
}

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

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

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

                (void) closedir(dirp);
        }

        /*
         * Create a local copy of the vendor/product/revision, strip out any
         * questionable characters, and then attempt to load each plugin.
         */
        vendor = strdupa(libscsi_vendor(tp->st_target));
        product = strdupa(libscsi_product(tp->st_target));
        revision = strdupa(libscsi_revision(tp->st_target));

        ses_plugin_cleanstr(vendor);
        ses_plugin_cleanstr(product);
        ses_plugin_cleanstr(revision);

        (void) snprintf(path, sizeof (path), "%s/%s/%s/%s%s", pluginroot,
            LIBSES_PLUGIN_VENDOR, isa, vendor,
            LIBSES_PLUGIN_EXT);
        if (ses_plugin_loadone(tp, path, 1) != 0)
                return (-1);

        (void) snprintf(path, sizeof (path), "%s/%s/%s/%s-%s%s", pluginroot,
            LIBSES_PLUGIN_VENDOR, isa, vendor, product,
            LIBSES_PLUGIN_EXT);
        if (ses_plugin_loadone(tp, path, 2) != 0)
                return (-1);

        (void) snprintf(path, sizeof (path), "%s/%s/%s/%s-%s-%s%s", pluginroot,
            LIBSES_PLUGIN_VENDOR, isa, vendor, product,
            revision, LIBSES_PLUGIN_EXT);
        if (ses_plugin_loadone(tp, path, 3) != 0)
                return (-1);

        return (0);
}

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

        if ((pluginpath = getenv("SES_PLUGINPATH")) == NULL)
                pluginpath = LIBSES_DEFAULT_PLUGINDIR;
        ses_plugin_dlclose = (getenv("SES_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 (ses_plugin_load_dir(tp, pluginroot) != 0)
                        return (-1);
        }

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

        return (0);
}

void
ses_plugin_unload(ses_target_t *tp)
{
        ses_plugin_t *sp;

        while ((sp = tp->st_plugin_first) != NULL) {
                tp->st_plugin_first = sp->sp_next;
                ses_plugin_destroy(sp);
        }
}