/*
 * 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 <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <libdevinfo.h>
#include <libhotplug.h>
#include <libhotplug_impl.h>
#include <sys/sunddi.h>
#include <sys/ddi_hp.h>
#include "hotplugd_impl.h"

/*
 * Define a list of hotplug nodes.
 * (Only used within this module.)
 */
typedef struct {
        hp_node_t       head;
        hp_node_t       prev;
} hp_node_list_t;

/*
 * Local functions.
 */
static int              copy_devinfo(const char *, const char *, uint_t,
                            hp_node_t *);
static int              copy_devices(hp_node_t, di_node_t, uint_t, hp_node_t *);
static int              copy_hotplug(hp_node_t, di_node_t, const char *, uint_t,
                            hp_node_t *);
static char             *base_path(const char *);
static int              search_cb(di_node_t, void *);
static int              check_search(di_node_t, uint_t);
static hp_node_t        new_device_node(hp_node_t, di_node_t);
static hp_node_t        new_hotplug_node(hp_node_t, di_hp_t);
static void             node_list_add(hp_node_list_t *, hp_node_t);

/*
 * getinfo()
 *
 *      Build a hotplug information snapshot.  The path, connection,
 *      and flags indicate what information should be included.
 */
int
getinfo(const char *path, const char *connection, uint_t flags, hp_node_t *retp)
{
        hp_node_t       root = NULL;
        hp_node_t       child;
        char            *basepath;
        int             rv;

        if ((path == NULL) || (retp == NULL))
                return (EINVAL);

        hp_dprintf("getinfo: path=%s, connection=%s, flags=0x%x\n", path,
            (connection == NULL) ? "NULL" : connection, flags);

        /* Allocate the base path */
        if ((basepath = base_path(path)) == NULL)
                return (ENOMEM);

        /* Copy in device and hotplug nodes from libdevinfo */
        if ((rv = copy_devinfo(basepath, connection, flags, &root)) != 0) {
                hp_fini(root);
                free(basepath);
                return (rv);
        }

        /* Check if there were no connections */
        if (root == NULL) {
                hp_dprintf("getinfo: no hotplug connections.\n");
                free(basepath);
                return (ENOENT);
        }

        /* Special case: exclude root nexus from snapshot */
        if (strcmp(basepath, "/") == 0) {
                child = root->hp_child;
                if (root->hp_name != NULL)
                        free(root->hp_name);
                free(root);
                root = child;
                for (child = root; child; child = child->hp_sibling)
                        child->hp_parent = NULL;
        }

        /* Store a pointer to the base path in each root node */
        for (child = root; child != NULL; child = child->hp_sibling)
                child->hp_basepath = basepath;

        /* Copy in usage information from RCM */
        if (flags & HPINFOUSAGE) {
                if ((rv = copy_usage(root)) != 0) {
                        (void) hp_fini(root);
                        return (rv);
                }
        }

        *retp = root;
        return (0);
}

/*
 * copy_devinfo()
 *
 *      Copy information about device and hotplug nodes from libdevinfo.
 *
 *      When path is set to "/", the results need to be limited only to
 *      branches that contain hotplug information.  An initial search
 *      is performed to mark which branches contain hotplug nodes.
 */
static int
copy_devinfo(const char *path, const char *connection, uint_t flags,
    hp_node_t *rootp)
{
        hp_node_t       hp_root = NULL;
        di_node_t       di_root;
        int             rv;

        /* Get libdevinfo snapshot */
        if ((di_root = di_init(path, DINFOSUBTREE | DINFOHP)) == DI_NODE_NIL)
                return (errno);

        /* Do initial search pass, if required */
        if (strcmp(path, "/") == 0) {
                flags |= HPINFOSEARCH;
                (void) di_walk_node(di_root, DI_WALK_CLDFIRST, NULL, search_cb);
        }

        /*
         * If a connection is specified, just copy immediate hotplug info.
         * Else, copy the device tree normally.
         */
        if (connection != NULL)
                rv = copy_hotplug(NULL, di_root, connection, flags, &hp_root);
        else
                rv = copy_devices(NULL, di_root, flags, &hp_root);

        /* Destroy devinfo snapshot */
        di_fini(di_root);

        *rootp = (rv == 0) ? hp_root : NULL;
        return (rv);
}

/*
 * copy_devices()
 *
 *      Copy a full branch of device nodes.  Used by copy_devinfo() and
 *      copy_hotplug().
 */
static int
copy_devices(hp_node_t parent, di_node_t dev, uint_t flags, hp_node_t *rootp)
{
        hp_node_list_t  children;
        hp_node_t       self, branch;
        di_node_t       child;
        int             rv = 0;

        /* Initialize results */
        *rootp = NULL;

        /* Enforce search semantics */
        if (check_search(dev, flags) == 0)
                return (0);

        /* Allocate new node for current device */
        if ((self = new_device_node(parent, dev)) == NULL)
                return (ENOMEM);

        /*
         * If the device has hotplug nodes, then use copy_hotplug()
         * instead to build the branch associated with current device.
         */
        if (di_hp_next(dev, DI_HP_NIL) != DI_HP_NIL) {
                if ((rv = copy_hotplug(self, dev, NULL, flags,
                    &self->hp_child)) != 0) {
                        free(self);
                        return (rv);
                }
                *rootp = self;
                return (0);
        }

        /*
         * The device does not have hotplug nodes.  Use normal
         * approach of iterating through its child device nodes.
         */
        (void) memset(&children, 0, sizeof (hp_node_list_t));
        for (child = di_child_node(dev); child != DI_NODE_NIL;
            child = di_sibling_node(child)) {
                branch = NULL;
                if ((rv = copy_devices(self, child, flags, &branch)) != 0) {
                        (void) hp_fini(children.head);
                        free(self);
                        return (rv);
                }
                if (branch != NULL)
                        node_list_add(&children, branch);
        }
        self->hp_child = children.head;

        /* Done */
        *rootp = self;
        return (0);
}

/*
 * copy_hotplug()
 *
 *      Copy a full branch of hotplug nodes.  Used by copy_devinfo()
 *      and copy_devices().
 *
 *      If a connection is specified, the results are limited only
 *      to the branch associated with that specific connection.
 */
static int
copy_hotplug(hp_node_t parent, di_node_t dev, const char *connection,
    uint_t flags, hp_node_t *retp)
{
        hp_node_list_t  connections, ports;
        hp_node_t       node, port_node;
        di_node_t       child_dev;
        di_hp_t         hp, port_hp;
        uint_t          child_flags;
        int             rv, physnum;

        /* Stop implementing the HPINFOSEARCH flag */
        child_flags = flags & ~(HPINFOSEARCH);

        /* Clear lists of discovered ports and connections */
        (void) memset(&ports, 0, sizeof (hp_node_list_t));
        (void) memset(&connections, 0, sizeof (hp_node_list_t));

        /*
         * Scan virtual ports.
         *
         * If a connection is specified and it matches a virtual port,
         * this will build the branch associated with that connection.
         * Else, this will only build branches for virtual ports that
         * are not associated with a physical connector.
         */
        for (hp = DI_HP_NIL; (hp = di_hp_next(dev, hp)) != DI_HP_NIL; ) {

                /* Ignore connectors */
                if (di_hp_type(hp) != DDI_HP_CN_TYPE_VIRTUAL_PORT)
                        continue;

                /*
                 * Ignore ports associated with connectors, unless
                 * a specific connection is being sought.
                 */
                if ((connection == NULL) && (di_hp_depends_on(hp) != -1))
                        continue;

                /* If a connection is specified, ignore non-matching ports */
                if ((connection != NULL) &&
                    (strcmp(di_hp_name(hp), connection) != 0))
                        continue;

                /* Create a new port node */
                if ((node = new_hotplug_node(parent, hp)) == NULL) {
                        rv = ENOMEM;
                        goto fail;
                }

                /* Add port node to connection list */
                node_list_add(&connections, node);

                /* Add branch of child devices to port node */
                if ((child_dev = di_hp_child(hp)) != DI_NODE_NIL)
                        if ((rv = copy_devices(node, child_dev, child_flags,
                            &node->hp_child)) != 0)
                                goto fail;
        }

        /*
         * Scan physical connectors.
         *
         * If a connection is specified, the results will be limited
         * only to the branch associated with that connection.
         */
        for (hp = DI_HP_NIL; (hp = di_hp_next(dev, hp)) != DI_HP_NIL; ) {

                /* Ignore ports */
                if (di_hp_type(hp) == DDI_HP_CN_TYPE_VIRTUAL_PORT)
                        continue;

                /* If a connection is specified, ignore non-matching ports */
                if ((connection != NULL) &&
                    (strcmp(di_hp_name(hp), connection) != 0))
                        continue;

                /* Create a new connector node */
                if ((node = new_hotplug_node(parent, hp)) == NULL) {
                        rv = ENOMEM;
                        goto fail;
                }

                /* Add connector node to connection list */
                node_list_add(&connections, node);

                /* Add branches of associated port nodes */
                physnum = di_hp_connection(hp);
                port_hp = DI_HP_NIL;
                while ((port_hp = di_hp_next(dev, port_hp)) != DI_HP_NIL) {

                        /* Ignore irrelevant connections */
                        if (di_hp_depends_on(port_hp) != physnum)
                                continue;

                        /* Add new port node to port list */
                        if ((port_node = new_hotplug_node(node,
                            port_hp)) == NULL) {
                                rv = ENOMEM;
                                goto fail;
                        }
                        node_list_add(&ports, port_node);

                        /* Add branch of child devices */
                        if ((child_dev = di_hp_child(port_hp)) != DI_NODE_NIL) {
                                if ((rv = copy_devices(port_node, child_dev,
                                    child_flags, &port_node->hp_child)) != 0)
                                        goto fail;
                        }
                }
                node->hp_child = ports.head;
                (void) memset(&ports, 0, sizeof (hp_node_list_t));
        }

        if (connections.head == NULL)
                return (ENXIO);
        *retp = connections.head;
        return (0);

fail:
        (void) hp_fini(ports.head);
        (void) hp_fini(connections.head);
        return (rv);
}

/*
 * base_path()
 *
 *      Normalize the base path of a hotplug information snapshot.
 *      The caller must free the string that is allocated.
 */
static char *
base_path(const char *path)
{
        char    *base_path;
        size_t  devices_len;

        devices_len = strlen(S_DEVICES);

        if (strncmp(path, S_DEVICES, devices_len) == 0)
                base_path = strdup(&path[devices_len]);
        else
                base_path = strdup(path);

        return (base_path);
}

/*
 * search_cb()
 *
 *      Callback function used by di_walk_node() to search for branches
 *      of the libdevinfo snapshot that contain hotplug nodes.
 */
/*ARGSUSED*/
static int
search_cb(di_node_t node, void *arg)
{
        di_node_t       parent;
        uint_t          flags;

        (void) di_node_private_set(node, (void *)(uintptr_t)0);

        if (di_hp_next(node, DI_HP_NIL) == DI_HP_NIL)
                return (DI_WALK_CONTINUE);

        for (parent = node; parent != DI_NODE_NIL;
            parent = di_parent_node(parent)) {
                flags = (uint_t)(uintptr_t)di_node_private_get(parent);
                flags |= HPINFOSEARCH;
                (void) di_node_private_set(parent, (void *)(uintptr_t)flags);
        }

        return (DI_WALK_CONTINUE);
}

/*
 * check_search()
 *
 *      Check if a device node was marked by an initial search pass.
 */
static int
check_search(di_node_t dev, uint_t flags)
{
        uint_t  dev_flags;

        if (flags & HPINFOSEARCH) {
                dev_flags = (uint_t)(uintptr_t)di_node_private_get(dev);
                if ((dev_flags & HPINFOSEARCH) == 0)
                        return (0);
        }

        return (1);
}

/*
 * node_list_add()
 *
 *      Utility function to append one node to a list of hotplug nodes.
 */
static void
node_list_add(hp_node_list_t *listp, hp_node_t node)
{
        if (listp->prev != NULL)
                listp->prev->hp_sibling = node;
        else
                listp->head = node;

        listp->prev = node;
}

/*
 * new_device_node()
 *
 *      Build a new hotplug node based on a specified devinfo node.
 */
static hp_node_t
new_device_node(hp_node_t parent, di_node_t dev)
{
        hp_node_t       node;
        char            *node_name, *bus_addr;
        char            name[MAXPATHLEN];

        node = (hp_node_t)calloc(1, sizeof (struct hp_node));

        if (node != NULL) {
                node->hp_parent = parent;
                node->hp_type = HP_NODE_DEVICE;

                node_name = di_node_name(dev);
                bus_addr = di_bus_addr(dev);
                if (bus_addr && (strlen(bus_addr) > 0)) {
                        if (snprintf(name, sizeof (name), "%s@%s", node_name,
                            bus_addr) >= sizeof (name)) {
                                log_err("Path too long for device node.\n");
                                free(node);
                                return (NULL);
                        }
                        node->hp_name = strdup(name);
                } else
                        node->hp_name = strdup(node_name);
        }

        return (node);
}

/*
 * new_hotplug_node()
 *
 *      Build a new hotplug node based on a specified devinfo hotplug node.
 */
static hp_node_t
new_hotplug_node(hp_node_t parent, di_hp_t hp)
{
        hp_node_t       node;
        char            *s;

        node = (hp_node_t)calloc(1, sizeof (struct hp_node));

        if (node != NULL) {
                node->hp_parent = parent;
                node->hp_state = di_hp_state(hp);
                node->hp_last_change = di_hp_last_change(hp);
                if ((s = di_hp_name(hp)) != NULL)
                        node->hp_name = strdup(s);
                if ((s = di_hp_description(hp)) != NULL)
                        node->hp_description = strdup(s);
                if (di_hp_type(hp) == DDI_HP_CN_TYPE_VIRTUAL_PORT)
                        node->hp_type = HP_NODE_PORT;
                else
                        node->hp_type = HP_NODE_CONNECTOR;
        }

        return (node);
}