/*
 * 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 <string.h>
#include <strings.h>
#include <unistd.h>
#include <stdlib.h>
#include <thread.h>
#include <synch.h>
#include <sys/types.h>
#include <ctype.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/modctl.h>
#include <errno.h>
#include <sys/openpromio.h>
#include <ftw.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
#include <limits.h>

#include "device_info.h"

/*
 * #define's
 */

/* alias node searching return values */
#define NO_MATCH        -1
#define EXACT_MATCH     1
#define INEXACT_MATCH   2

/* for prom io operations */
#define BUFSIZE         4096
#define MAXPROPSIZE     256
#define MAXVALSIZE      (BUFSIZE - MAXPROPSIZE - sizeof (uint_t))

/* prom_obp_vers() return values */
#define OBP_OF                  0x4     /* versions OBP 3.x */
#define OBP_NO_ALIAS_NODE       0x8     /* No alias node */

/* for nftw call */
#define FT_DEPTH        15

/* default logical and physical device name space */
#define DEV     "/dev"
#define DEVICES "/devices"

/* for boot device identification on x86 */
#define CREATE_DISKMAP          "/boot/solaris/bin/create_diskmap"
#define GRUBDISK_MAP            "/var/run/solaris_grubdisk.map"

/*
 * internal structure declarations
 */

/* for prom io functions */
typedef union {
        char buf[BUFSIZE];
        struct openpromio opp;
} Oppbuf;

/* used to manage lists of devices and aliases */
struct name_list {
        char *name;
        struct name_list *next;
};

/*
 * internal global data
 */

/* global since nftw does not let you pass args to be updated */
static struct name_list **dev_list;

/* global since nftw does not let you pass args to be updated */
static struct boot_dev **bootdev_list;

/* mutex to protect bootdev_list and dev_list */
static mutex_t dev_lists_lk = DEFAULTMUTEX;

/*
 * internal function prototypes
 */

static int prom_open(int);
static void prom_close(int);
static int is_openprom(int);

static int prom_dev_to_alias(char *dev, uint_t options, char ***ret_buf);
static int alias_to_prom_dev(char *alias, char *ret_buf);
static int prom_srch_aliases_by_def(char *, struct name_list **,
    struct name_list **, int);
static int prom_find_aliases_node(int fd);
static int prom_compare_devs(char *prom_dev1, char *prom_dev2);
static int _prom_strcmp(char *s1, char *s2);
static int prom_srch_node(int fd, char *prop_name, char *ret_buf);
static uint_t prom_next_node(int fd, uint_t node_id);
static uint_t prom_child_node(int fd, uint_t node_id);

static int prom_obp_vers(void);

static void parse_name(char *, char **, char **, char **);
static int process_bootdev(const char *, const char *, struct boot_dev ***);
static int process_minor_name(char *dev_path, const char *default_root);
static void options_override(char *prom_path, char *alias_name);
static int devfs_phys_to_logical(struct boot_dev **bootdev_array,
        const int array_size, const char *default_root);
static int check_logical_dev(const char *, const struct stat *, int,
        struct FTW *);
static struct boot_dev *alloc_bootdev(char *);
static void free_name_list(struct name_list *list, int free_name);
static int insert_alias_list(struct name_list **list,
        char *alias_name);
static int get_boot_dev_var(struct openpromio *opp);
static int set_boot_dev_var(struct openpromio *opp, char *bootdev);
static int devfs_prom_to_dev_name(char *prom_path, char *dev_path);
static int devfs_dev_to_prom_names(char *dev_path, char *prom_path, size_t len);

/*
 * frees a list of paths from devfs_get_prom_name_list
 */
static void
prom_list_free(char **prom_list)
{
        int i = 0;

        if (!prom_list)
                return;

        while (prom_list[i]) {
                free(prom_list[i]);
                i++;
        }
        free(prom_list);
}

static int
devfs_get_prom_name_list(const char *dev_name, char ***prom_list)
{
        char *prom_path = NULL;
        int count = 0;          /* # of slots we will need in prom_list */
        int ret, i, len;
        char **list;
        char *ptr;

        if (dev_name == NULL)
                return (DEVFS_INVAL);
        if (*dev_name != '/')
                return (DEVFS_INVAL);
        if (prom_list == NULL)
                return (DEVFS_INVAL);

        /*
         * make sure we are on a machine which supports a prom
         * and we have permission to use /dev/openprom
         */
        if ((ret = prom_obp_vers()) < 0)
                return (ret);
        if ((prom_path = (char *)malloc(MAXVALSIZE)) == NULL)
                return (DEVFS_NOMEM);
        /*
         * get the prom path name
         */
        ret = devfs_dev_to_prom_names((char *)dev_name, prom_path, MAXVALSIZE);
        if (ret < 0) {
                free(prom_path);
                return (ret);
        }
        /* deal with list of names */
        for (i = 0; i < ret; i++)
                if (prom_path[i] == '\0')
                        count++;

        if ((list = (char **)calloc(count + 1, sizeof (char *))) == NULL) {
                free(prom_path);
                return (DEVFS_NOMEM);
        }

        ptr = prom_path;
        for (i = 0; i < count; i++) {
                len = strlen(ptr) + 1;
                if ((list[i] = (char *)malloc(len)) == NULL) {
                        free(prom_path);
                        free(list);
                        return (DEVFS_NOMEM);
                }
                (void) snprintf(list[i], len, "%s", ptr);
                ptr += len;
        }

        free(prom_path);

        *prom_list = list;
        return (0);
}

/*
 * retrieve the list of prom representations for a given device name
 * the list will be sorted in the following order: exact aliases,
 * inexact aliases, prom device path name.  If multiple matches occur
 * for exact or inexact aliases, then these are sorted in collating
 * order. The list is returned in prom_list
 *
 * the list may be restricted by specifying the correct flags in options.
 */
int
devfs_get_prom_names(const char *dev_name, uint_t options, char ***prom_list)
{
        char *prom_path = NULL;
        int count = 0;          /* # of slots we will need in prom_list */
        char **alias_list = NULL;
        char **list;
        int ret;

        if (dev_name == NULL) {
                return (DEVFS_INVAL);
        }
        if (*dev_name != '/') {
                return (DEVFS_INVAL);
        }
        if (prom_list == NULL) {
                return (DEVFS_INVAL);
        }
        /*
         * make sure we are on a machine which supports a prom
         * and we have permission to use /dev/openprom
         */
        if ((ret = prom_obp_vers()) < 0) {
                return (ret);
        }
        if ((prom_path = (char *)malloc(MAXPATHLEN)) == NULL) {
                return (DEVFS_NOMEM);
        }
        /*
         * get the prom path name
         */
        ret = devfs_dev_to_prom_name((char *)dev_name, prom_path);
        if (ret < 0) {
                free(prom_path);
                return (ret);
        }
        /* get the list of aliases (exact and inexact) */
        if ((ret = prom_dev_to_alias(prom_path, options, &alias_list)) < 0) {
                free(prom_path);
                return (ret);
        }
        /* now figure out how big the return array must be */
        if (alias_list != NULL) {
                while (alias_list[count] != NULL) {
                        count++;
                }
        }
        if ((options & BOOTDEV_NO_PROM_PATH) == 0) {
                count++;        /* # of slots we will need in prom_list */
        }
        count++;        /* for the null terminator */

        /* allocate space for the list */
        if ((list = (char **)calloc(count, sizeof (char *))) == NULL) {
                count = 0;
                while ((alias_list) && (alias_list[count] != NULL)) {
                        free(alias_list[count]);
                        count++;
                }
                free(alias_list);
                free(prom_path);
                return (DEVFS_NOMEM);
        }
        /* fill in the array and free the name list of aliases. */
        count = 0;
        while ((alias_list) && (alias_list[count] != NULL)) {
                list[count] = alias_list[count];
                count++;
        }
        if ((options & BOOTDEV_NO_PROM_PATH) == 0) {
                list[count] = prom_path;
        }
        if (alias_list != NULL) {
                free(alias_list);
        }
        *prom_list = list;
        return (0);
}

/*
 * Get a list prom-path translations for a solaris device.
 *
 * Returns the number of and all OBP paths and alias variants that
 * reference the Solaris device path passed in.
 */
int
devfs_get_all_prom_names(const char *solaris_path, uint_t flags,
    struct devfs_prom_path **paths)
{
        int ret, len, i, count = 0;
        char *ptr, *prom_path;
        struct devfs_prom_path *cur = NULL, *new;

        if ((ret = prom_obp_vers()) < 0)
                return (ret);
        if ((prom_path = (char *)malloc(MAXVALSIZE)) == NULL)
                return (DEVFS_NOMEM);

        if ((ret = devfs_dev_to_prom_names((char *)solaris_path,
            prom_path, MAXVALSIZE)) < 0) {
                free(prom_path);
                return (ret);
        }

        for (i = 0; i < ret; i++)
                if (prom_path[i] == '\0')
                        count++;

        *paths = NULL;
        ptr = prom_path;
        for (i = 0; i < count; i++) {
                if ((new = (struct devfs_prom_path *)calloc(
                    sizeof (struct devfs_prom_path), 1)) == NULL) {
                        free(prom_path);
                        devfs_free_all_prom_names(*paths);
                        return (DEVFS_NOMEM);
                }

                if (cur == NULL)
                        *paths = new;
                else
                        cur->next = new;
                cur = new;

                len = strlen(ptr) + 1;
                if ((cur->obp_path = (char *)calloc(len, 1)) == NULL) {
                        free(prom_path);
                        devfs_free_all_prom_names(*paths);
                        return (DEVFS_NOMEM);
                }

                (void) snprintf(cur->obp_path, len, "%s", ptr);
                ptr += len;
                if ((ret = prom_dev_to_alias(cur->obp_path, flags,
                    &(cur->alias_list))) < 0) {
                        free(prom_path);
                        devfs_free_all_prom_names(*paths);
                        return (ret);
                }
        }

        free(prom_path);
        return (count);
}

void
devfs_free_all_prom_names(struct devfs_prom_path *paths)
{
        int i;

        if (paths == NULL)
                return;

        devfs_free_all_prom_names(paths->next);

        if (paths->obp_path != NULL)
                free(paths->obp_path);

        if (paths->alias_list != NULL) {
                for (i = 0; paths->alias_list[i] != NULL; i++)
                        if (paths->alias_list[i] != NULL)
                                free(paths->alias_list[i]);

                free(paths->alias_list);
        }

        free(paths);
}

/*
 * Accepts a device name as an input argument.  Uses this to set the
 * boot-device (or like) variable
 *
 * By default, this routine prepends to the list and converts the
 * logical device name to its most compact prom representation.
 * Available options include: converting the device name to a prom
 * path name (but not an alias) or performing no conversion at all;
 * overwriting the existing contents of boot-device rather than
 * prepending.
 */
int
devfs_bootdev_set_list(const char *dev_name, const uint_t options)
{
        char *prom_path;
        char *new_bootdev;
        char *ptr;
        char **alias_list = NULL;
        char **prom_list = NULL;
        Oppbuf  oppbuf;
        struct openpromio *opp = &(oppbuf.opp);
        int ret, len, i, j;

        if (devfs_bootdev_modifiable() != 0) {
                return (DEVFS_NOTSUP);
        }
        if (dev_name == NULL) {
                return (DEVFS_INVAL);
        }
        if (strlen(dev_name) >= MAXPATHLEN)
                return (DEVFS_INVAL);

        if ((*dev_name != '/') && !(options & BOOTDEV_LITERAL)) {
                return (DEVFS_INVAL);
        }
        if ((options & BOOTDEV_LITERAL) && (options & BOOTDEV_PROMDEV)) {
                return (DEVFS_INVAL);
        }
        /*
         * if we are prepending, make sure that this obp rev
         * supports multiple boot device entries.
         */
        ret = prom_obp_vers();
        if (ret < 0) {
                return (ret);
        }

        if ((prom_path = (char *)malloc(MAXVALSIZE)) == NULL) {
                return (DEVFS_NOMEM);
        }
        if (options & BOOTDEV_LITERAL) {
                (void) strcpy(prom_path, dev_name);
        } else {
                /* need to convert to prom representation */
                ret = devfs_get_prom_name_list(dev_name, &prom_list);
                if (ret < 0) {
                        free(prom_path);
                        return (ret);
                }

                len = MAXVALSIZE;
                i = 0;
                ptr = prom_path;
                while (prom_list && prom_list[i]) {
                        if (!(options & BOOTDEV_PROMDEV)) {
                                ret = prom_dev_to_alias(prom_list[i], 0,
                                    &alias_list);
                                if (ret < 0) {
                                        free(prom_path);
                                        prom_list_free(prom_list);
                                        return (ret);
                                }
                                if ((alias_list != NULL) &&
                                    (alias_list[0] != NULL)) {
                                        (void) snprintf(ptr, len, "%s ",
                                            alias_list[0]);
                                        for (ret = 0; alias_list[ret] != NULL;
                                            ret++)
                                                free(alias_list[ret]);
                                } else {
                                        (void) snprintf(ptr, len, "%s ",
                                            prom_list[i]);
                                }
                                if (alias_list != NULL)
                                        free(alias_list);
                        } else {
                                (void) snprintf(ptr, len, "%s ", prom_list[i]);
                        }
                        j = strlen(ptr);
                        len -= j;
                        ptr += j;
                        i++;
                }
                ptr--;
                *ptr = 0;

                prom_list_free(prom_list);
        }
        if (options & BOOTDEV_OVERWRITE) {
                new_bootdev = prom_path;
        } else {
                /* retrieve the current value of boot-device */
                ret = get_boot_dev_var(opp);
                if (ret < 0) {
                        free(prom_path);
                        return (ret);
                }
                /* prepend new entry - deal with duplicates */
                new_bootdev = (char *)malloc(strlen(opp->oprom_array)
                    + strlen(prom_path) + 2);
                if (new_bootdev == NULL) {
                        free(prom_path);
                        return (DEVFS_NOMEM);
                }
                (void) strcpy(new_bootdev, prom_path);
                if (opp->oprom_size > 0) {
                        for (ptr = strtok(opp->oprom_array, " "); ptr != NULL;
                            ptr = strtok(NULL, " ")) {
                                /* we strip out duplicates */
                                if (strcmp(prom_path, ptr) == 0) {
                                        continue;
                                }
                                (void) strcat(new_bootdev, " ");
                                (void) strcat(new_bootdev, ptr);
                        }
                }
        }

        /* now set the new value */
        ret = set_boot_dev_var(opp, new_bootdev);

        if (options & BOOTDEV_OVERWRITE) {
                free(prom_path);
        } else {
                free(new_bootdev);
                free(prom_path);
        }

        return (ret);
}

/*
 * sets the string bootdev as the new value for boot-device
 */
static int
set_boot_dev_var(struct openpromio *opp, char *bootdev)
{
        int prom_fd;
        int i;
        int ret;
        char *valbuf;
        char *save_bootdev;
        char *bootdev_variables[] = {
                "boot-device",
                "bootdev",
                "boot-from",
                NULL
        };
        int found = 0;
        int *ip = (int *)((void *)opp->oprom_array);

        /* query the prom */
        prom_fd = prom_open(O_RDWR);
        if (prom_fd < 0) {
                return (prom_fd);
        }

        /* get the diagnostic-mode? property */
        (void) strcpy(opp->oprom_array, "diagnostic-mode?");
        opp->oprom_size = MAXVALSIZE;
        if (ioctl(prom_fd, OPROMGETOPT, opp) >= 0) {
                if ((opp->oprom_size > 0) &&
                    (strcmp(opp->oprom_array, "true") == 0)) {
                        prom_close(prom_fd);
                        return (DEVFS_ERR);
                }
        }
        /* get the diag-switch? property */
        (void) strcpy(opp->oprom_array, "diag-switch?");
        opp->oprom_size = MAXVALSIZE;
        if (ioctl(prom_fd, OPROMGETOPT, opp) >= 0) {
                if ((opp->oprom_size > 0) &&
                    (strcmp(opp->oprom_array, "true") == 0)) {
                        prom_close(prom_fd);
                        return (DEVFS_ERR);
                }
        }
        /*
         * look for one of the following properties in order:
         *      boot-device
         *      bootdev
         *      boot-from
         *
         * Use the first one that we find.
         */
        *ip = 0;
        opp->oprom_size = MAXPROPSIZE;
        while ((opp->oprom_size != 0) && (!found)) {
                opp->oprom_size = MAXPROPSIZE;
                if (ioctl(prom_fd, OPROMNXTOPT, opp) < 0) {
                        break;
                }
                for (i = 0; bootdev_variables[i] != NULL; i++) {
                        if (strcmp(opp->oprom_array, bootdev_variables[i])
                            == 0) {
                                found = 1;
                                break;
                        }
                }
        }
        if (found) {
                (void) strcpy(opp->oprom_array, bootdev_variables[i]);
                opp->oprom_size = MAXVALSIZE;
                if (ioctl(prom_fd, OPROMGETOPT, opp) < 0) {
                        prom_close(prom_fd);
                        return (DEVFS_NOTSUP);
                }
        } else {
                prom_close(prom_fd);
                return (DEVFS_NOTSUP);
        }

        /* save the old copy in case we fail */
        if ((save_bootdev = strdup(opp->oprom_array)) == NULL) {
                prom_close(prom_fd);
                return (DEVFS_NOMEM);
        }
        /* set up the new value of boot-device */
        (void) strcpy(opp->oprom_array, bootdev_variables[i]);
        valbuf = opp->oprom_array + strlen(opp->oprom_array) + 1;
        (void) strcpy(valbuf, bootdev);

        opp->oprom_size = strlen(valbuf) + strlen(opp->oprom_array) + 2;

        if (ioctl(prom_fd, OPROMSETOPT, opp) < 0) {
                free(save_bootdev);
                prom_close(prom_fd);
                return (DEVFS_ERR);
        }

        /*
         * now read it back to make sure it took
         */
        (void) strcpy(opp->oprom_array, bootdev_variables[i]);
        opp->oprom_size = MAXVALSIZE;
        if (ioctl(prom_fd, OPROMGETOPT, opp) >= 0) {
                if (_prom_strcmp(opp->oprom_array, bootdev) == 0) {
                        /* success */
                        free(save_bootdev);
                        prom_close(prom_fd);
                        return (0);
                }
                /* deal with setting it to "" */
                if ((strlen(bootdev) == 0) && (opp->oprom_size == 0)) {
                        /* success */
                        free(save_bootdev);
                        prom_close(prom_fd);
                        return (0);
                }
        }
        /*
         * something did not take - write out the old value and
         * hope that we can restore things...
         *
         * unfortunately, there is no way for us to differentiate
         * whether we exceeded the maximum number of characters
         * allowable.  The limit varies from prom rev to prom
         * rev, and on some proms, when the limit is
         * exceeded, whatever was in the
         * boot-device variable becomes unreadable.
         *
         * so if we fail, we will assume we ran out of room.  If we
         * not able to restore the original setting, then we will
         * return DEVFS_ERR instead.
         */
        ret = DEVFS_LIMIT;
        (void) strcpy(opp->oprom_array, bootdev_variables[i]);
        valbuf = opp->oprom_array + strlen(opp->oprom_array) + 1;
        (void) strcpy(valbuf, save_bootdev);

        opp->oprom_size = strlen(valbuf) + strlen(opp->oprom_array) + 2;

        if (ioctl(prom_fd, OPROMSETOPT, opp) < 0) {
                ret = DEVFS_ERR;
        }
        free(save_bootdev);
        prom_close(prom_fd);
        return (ret);
}
/*
 * retrieve the current value for boot-device
 */
static int
get_boot_dev_var(struct openpromio *opp)
{
        int prom_fd;
        int i;
        char *bootdev_variables[] = {
                "boot-device",
                "bootdev",
                "boot-from",
                NULL
        };
        int found = 0;
        int *ip = (int *)((void *)opp->oprom_array);

        /* query the prom */
        prom_fd = prom_open(O_RDONLY);
        if (prom_fd < 0) {
                return (prom_fd);
        }

        /* get the diagnostic-mode? property */
        (void) strcpy(opp->oprom_array, "diagnostic-mode?");
        opp->oprom_size = MAXVALSIZE;
        if (ioctl(prom_fd, OPROMGETOPT, opp) >= 0) {
                if ((opp->oprom_size > 0) &&
                    (strcmp(opp->oprom_array, "true") == 0)) {
                        prom_close(prom_fd);
                        return (DEVFS_ERR);
                }
        }
        /* get the diag-switch? property */
        (void) strcpy(opp->oprom_array, "diag-switch?");
        opp->oprom_size = MAXVALSIZE;
        if (ioctl(prom_fd, OPROMGETOPT, opp) >= 0) {
                if ((opp->oprom_size > 0) &&
                    (strcmp(opp->oprom_array, "true") == 0)) {
                        prom_close(prom_fd);
                        return (DEVFS_ERR);
                }
        }
        /*
         * look for one of the following properties in order:
         *      boot-device
         *      bootdev
         *      boot-from
         *
         * Use the first one that we find.
         */
        *ip = 0;
        opp->oprom_size = MAXPROPSIZE;
        while ((opp->oprom_size != 0) && (!found)) {
                opp->oprom_size = MAXPROPSIZE;
                if (ioctl(prom_fd, OPROMNXTOPT, opp) < 0) {
                        break;
                }
                for (i = 0; bootdev_variables[i] != NULL; i++) {
                        if (strcmp(opp->oprom_array, bootdev_variables[i])
                            == 0) {
                                found = 1;
                                break;
                        }
                }
        }
        if (found) {
                (void) strcpy(opp->oprom_array, bootdev_variables[i]);
                opp->oprom_size = MAXVALSIZE;
                if (ioctl(prom_fd, OPROMGETOPT, opp) < 0) {
                        prom_close(prom_fd);
                        return (DEVFS_ERR);
                }
                /* boot-device exists but contains nothing */
                if (opp->oprom_size == 0) {
                        *opp->oprom_array = '\0';
                }
        } else {
                prom_close(prom_fd);
                return (DEVFS_NOTSUP);
        }
        prom_close(prom_fd);
        return (0);
}

#ifndef __sparc
static FILE *
open_diskmap(void)
{
        FILE *fp;
        char cmd[PATH_MAX];

        /* make sure we have a map file */
        fp = fopen(GRUBDISK_MAP, "r");
        if (fp == NULL) {
                (void) snprintf(cmd, sizeof (cmd),
                    "%s > /dev/null", CREATE_DISKMAP);
                (void) system(cmd);
                fp = fopen(GRUBDISK_MAP, "r");
        }
        return (fp);
}

static int
find_x86_boot_device(struct openpromio *opp)
{
        int ret = DEVFS_ERR;
        char *cp, line[MAXVALSIZE + 6];
        FILE *file;

        file = open_diskmap();
        if (file == NULL)
                return (DEVFS_ERR);

        while (fgets(line, MAXVALSIZE + 6, file)) {
                if (strncmp(line, "0 ", 2) != 0)
                        continue;
                /* drop new-line */
                line[strlen(line) - 1] = '\0';
                /*
                 * an x86 BIOS only boots a disk, not a partition
                 * or a slice, so hard-code :q (p0)
                 */
                cp = strchr(line + 2, ' ');
                if (cp == NULL)
                        break;
                (void) snprintf(opp->oprom_array, MAXVALSIZE,
                    "%s:q", cp + 1);
                opp->oprom_size = MAXVALSIZE;
                ret = 0;
                break;
        }
        (void) fclose(file);
        return (ret);
}
#endif /* ndef __sparc */

/*
 * retrieve the list of entries in the boot-device configuration
 * variable.  An array of boot_dev structs will be created, one entry
 * for each device name in the boot-device variable.  Each entry
 * in the array will contain the logical device representation of the
 * boot-device entry, if any.
 *
 * default_root. if set, is used to locate logical device entries in
 * directories other than /dev
 */
int
devfs_bootdev_get_list(const char *default_root,
    struct boot_dev ***bootdev_list)
{
        Oppbuf  oppbuf;
        struct openpromio *opp = &(oppbuf.opp);
        int i;
        struct boot_dev **tmp_list;

        if (default_root == NULL) {
                default_root = "";
        } else if (*default_root != '/') {
                return (DEVFS_INVAL);
        }

        if (bootdev_list == NULL) {
                return (DEVFS_INVAL);
        }

        /* get the boot-device variable */
#if defined(sparc)
        i = get_boot_dev_var(opp);
#else
        i = find_x86_boot_device(opp);
#endif
        if (i < 0) {
                return (i);
        }
        /* now try to translate each entry to a logical device. */
        i = process_bootdev(opp->oprom_array, default_root, &tmp_list);
        if (i == 0) {
                *bootdev_list = tmp_list;
                return (0);
        } else {
                return (i);
        }
}

/*
 * loop thru the list of entries in a boot-device configuration
 * variable.
 */
static int
process_bootdev(const char *bootdevice, const char *default_root,
    struct boot_dev ***list)
{
        int i;
        char *entry, *ptr;
        char prom_path[MAXPATHLEN];
        char ret_buf[MAXPATHLEN];
        struct boot_dev **bootdev_array;
        int num_entries = 0;
        int found = 0;
        int vers;

        if ((entry = (char *)malloc(strlen(bootdevice) + 1)) == NULL) {
                return (DEVFS_NOMEM);
        }
        /* count the number of entries */
        (void) strcpy(entry, bootdevice);
        for (ptr = strtok(entry, " "); ptr != NULL;
            ptr = strtok(NULL, " ")) {
                num_entries++;
        }
        (void) strcpy(entry, bootdevice);

        bootdev_array = (struct boot_dev **)
            calloc((size_t)num_entries + 1, sizeof (struct boot_dev *));

        if (bootdev_array == NULL) {
                free(entry);
                return (DEVFS_NOMEM);
        }

        vers = prom_obp_vers();
        if (vers < 0) {
                free(entry);
                return (vers);
        }

        /* for each entry in boot-device, do... */
        for (ptr = strtok(entry, " "), i = 0; ptr != NULL;
            ptr = strtok(NULL, " "), i++) {

                if ((bootdev_array[i] = alloc_bootdev(ptr)) == NULL) {
                        devfs_bootdev_free_list(bootdev_array);
                        free(entry);
                        return (DEVFS_NOMEM);
                }

                /*
                 * prom boot-device may be aliased, so we need to do
                 * the necessary prom alias to dev translation.
                 */
                if (*ptr != '/') {
                        if (alias_to_prom_dev(ptr, prom_path) < 0) {
                                continue;
                        }
                } else {
                        (void) strcpy(prom_path, ptr);
                }

                /* now we have a prom device path - convert to a devfs name */
                if (devfs_prom_to_dev_name(prom_path, ret_buf) < 0) {
                        continue;
                }

                /* append any default minor names necessary */
                if (process_minor_name(ret_buf, default_root) < 0) {
                        continue;
                }
                found = 1;

                /*
                 * store the physical device path for now - when
                 * we are all done with the entries, we will convert
                 * these to their logical device name equivalents
                 */
                bootdev_array[i]->bootdev_trans[0] = strdup(ret_buf);
        }
        /*
         * Convert all of the boot-device entries that translated to a
         * physical device path in /devices to a logical device path
         * in /dev (note that there may be several logical device paths
         * associated with a single physical device path - return them all
         */
        if (found) {
                if (devfs_phys_to_logical(bootdev_array, num_entries,
                    default_root) < 0) {
                        devfs_bootdev_free_list(bootdev_array);
                        bootdev_array = NULL;
                }
        }
        free(entry);
        *list = bootdev_array;
        return (0);
}

/*
 * We may get a device path from the prom that has no minor name
 * information included in it.  Since this device name will not
 * correspond directly to a physical device in /devices, we do our
 * best to append what the default minor name should be and try this.
 *
 * For sparc: we append slice 0 (:a).
 * For x86: we append fdisk partition 0 (:q).
 */
static int
process_minor_name(char *dev_path, const char *root)
{
        char *cp;
#if defined(sparc)
        const char *default_minor_name = "a";
#else
        const char *default_minor_name = "q";
#endif
        int n;
        struct stat stat_buf;
        char path[MAXPATHLEN];

        (void) snprintf(path, sizeof (path), "%s%s%s", root, DEVICES, dev_path);
        /*
         * if the device file already exists as given to us, there
         * is nothing to do but return.
         */
        if (stat(path, &stat_buf) == 0) {
                return (0);
        }
        /*
         * if there is no ':' after the last '/' character, or if there is
         * a ':' with no specifier, append the default segment specifier
         * ; if there is a ':' followed by a digit, this indicates
         * a partition number (which does not map into the /devices name
         * space), so strip the number and replace it with the letter
         * that represents the partition index
         */
        if ((cp = strrchr(dev_path, '/')) != NULL) {
                if ((cp = strchr(cp, ':')) == NULL) {
                        (void) strcat(dev_path, ":");
                        (void) strcat(dev_path, default_minor_name);
                } else if (*++cp == '\0') {
                        (void) strcat(dev_path, default_minor_name);
                } else if (isdigit(*cp)) {
                        n = atoi(cp);
                        /* make sure to squash the digit */
                        *cp = '\0';
                        switch (n) {
                        case 0: (void) strcat(dev_path, "q");
                                        break;
                        case 1: (void) strcat(dev_path, "r");
                                        break;
                        case 2: (void) strcat(dev_path, "s");
                                        break;
                        case 3: (void) strcat(dev_path, "t");
                                        break;
                        case 4: (void) strcat(dev_path, "u");
                                        break;
                        default: (void) strcat(dev_path, "a");
                                        break;
                        }
                }
        }
        /*
         * see if we can find something now.
         */
        (void) snprintf(path, sizeof (path), "%s%s%s", root, DEVICES, dev_path);

        if (stat(path, &stat_buf) == 0) {
                return (0);
        } else {
                return (-1);
        }
}

/*
 * for each entry in bootdev_array, convert the physical device
 * representation of the boot-device entry to one or more logical device
 * entries.  We use the hammer method - walk through the logical device
 * name space looking for matches (/dev).  We use nftw to do this.
 */
static int
devfs_phys_to_logical(struct boot_dev **bootdev_array, const int array_size,
    const char *default_root)
{
        int walk_flags = FTW_PHYS | FTW_MOUNT;
        char *full_path;
        struct name_list *list;
        int count, i;
        char **dev_name_array;
        size_t default_root_len;
        char *dev_dir = DEV;
        int len;

        if (array_size < 0) {
                return (-1);
        }

        if (bootdev_array == NULL) {
                return (-1);
        }
        if (default_root == NULL) {
                return (-1);
        }
        default_root_len = strlen(default_root);
        if ((default_root_len != 0) && (*default_root != '/')) {
                return (-1);
        }

        /* short cut for an empty array */
        if (*bootdev_array == NULL) {
                return (0);
        }

        /* tell nftw where to start (default: /dev) */
        len = default_root_len + strlen(dev_dir) + 1;
        if ((full_path = (char *)malloc(len)) == NULL) {
                return (-1);
        }

        /*
         * if the default root path is terminated with a /, we have to
         * make sure we don't end up with one too many slashes in the
         * path we are building.
         */
        if ((default_root_len > (size_t)0) &&
            (default_root[default_root_len - 1] == '/')) {
                (void) snprintf(full_path, len, "%s%s", default_root,
                    &dev_dir[1]);
        } else {
                (void) snprintf(full_path, len, "%s%s", default_root, dev_dir);
        }

        /*
         * we need to muck with global data to make nftw work
         * so single thread access
         */
        (void) mutex_lock(&dev_lists_lk);

        /*
         * set the global vars bootdev_list and dev_list for use by nftw
         * dev_list is an array of lists - one for each boot-device
         * entry.  The nftw function will create a list of logical device
         * entries for each boot-device and put all of the lists in
         * dev_list.
         */
        dev_list = (struct name_list **)
            calloc(array_size, sizeof (struct name_list *));
        if (dev_list == NULL) {
                free(full_path);
                (void) mutex_unlock(&dev_lists_lk);
                return (-1);
        }
        bootdev_list = bootdev_array;

        if (nftw(full_path, check_logical_dev, FT_DEPTH, walk_flags) == -1) {
                bootdev_list = NULL;
                free(full_path);
                for (i = 0; i < array_size; i++) {
                        free_name_list(dev_list[i], 1);
                }
                /* don't free dev_list here because it's been handed off */
                dev_list = NULL;
                (void) mutex_unlock(&dev_lists_lk);
                return (-1);
        }

        /*
         * now we have a filled in dev_list.  So for each logical device
         * list in dev_list, count the number of entries in the list,
         * create an array of strings of logical devices, and save in the
         * corresponding boot_dev structure.
         */
        for (i = 0; i < array_size; i++) {
                /* get the next list */
                list = dev_list[i];
                count = 0;

                /* count the number of entries in the list */
                while (list != NULL) {
                        count++;
                        list = list->next;
                }
                if ((dev_name_array =
                    (char **)malloc((count + 1) * sizeof (char *)))
                    == NULL) {
                        continue;
                }
                list = dev_list[i];
                count = 0;

                /* fill in the array */
                while (list != NULL) {
                        dev_name_array[count] = list->name;
                        count++;
                        list = list->next;
                }

                /*
                 * null terminate the array
                 */
                dev_name_array[count] = NULL;
                if ((bootdev_array[i] != NULL) && (bootdev_array[i]->
                    bootdev_trans[0] != NULL)) {
                        free(bootdev_array[i]->bootdev_trans[0]);
                }
                if (bootdev_array[i] != NULL) {
                        free(bootdev_array[i]->bootdev_trans);
                        bootdev_array[i]->bootdev_trans = dev_name_array;
                }
        }
        bootdev_list = NULL;
        free(full_path);
        for (i = 0; i < array_size; i++) {
                free_name_list(dev_list[i], 0);
        }
        free(dev_list);
        dev_list = NULL;
        (void) mutex_unlock(&dev_lists_lk);
        return (0);
}
/*
 * nftw function
 * for a logical dev entry, it walks the list of boot-devices and
 * sees if there are any matches.  If so, it saves the logical device
 * name off in the appropriate list in dev_list
 */
/* ARGSUSED */
static int
check_logical_dev(const char *node, const struct stat *node_stat, int flags,
    struct FTW *ftw_info)
{
        char link_buf[MAXPATHLEN];
        int link_buf_len;
        char *name;
        struct name_list *dev;
        char *physdev;
        int i;

        if (flags != FTW_SL) {
                return (0);
        }

        if ((link_buf_len = readlink(node, (void *)link_buf, MAXPATHLEN))
            == -1) {
                return (0);
        }
        link_buf[link_buf_len] = '\0';
        if ((name = strstr(link_buf, DEVICES)) == NULL) {
                return (0);
        }
        name = (char *)(name + strlen(DEVICES));

        for (i = 0; bootdev_list[i] != NULL; i++) {
                if (bootdev_list[i]->bootdev_trans[0] == NULL) {
                        continue;
                }
                /*
                 * compare the contents of the link with the physical
                 * device representation of this boot device
                 */
                physdev = bootdev_list[i]->bootdev_trans[0];
                if ((strcmp(name, physdev) == 0) &&
                    (strlen(name) == strlen(physdev))) {
                        if ((dev = (struct name_list *)
                            malloc(sizeof (struct name_list))) == NULL) {
                                return (-1);
                        }
                        if ((dev->name = strdup(node)) == NULL) {
                                free(dev);
                                return (-1);
                        }
                        if (dev_list[i] == NULL) {
                                dev_list[i] = dev;
                                dev_list[i]->next = NULL;
                        } else {
                                dev->next = dev_list[i];
                                dev_list[i] = dev;
                        }
                }
        }
        return (0);
}

/*
 * frees a list of boot_dev struct pointers
 */
void
devfs_bootdev_free_list(struct boot_dev **array)
{
        int i = 0;
        int j;

        if (array == NULL) {
                return;
        }

        while (array[i] != NULL) {
                free(array[i]->bootdev_element);
                j = 0;
                while (array[i]->bootdev_trans[j] != NULL) {
                        free(array[i]->bootdev_trans[j++]);
                }
                free(array[i]->bootdev_trans);
                free(array[i]);
                i++;
        }
        free(array);
}
/*
 * allocates a boot_dev struct and fills in the bootdev_element portion
 */
static struct boot_dev *
alloc_bootdev(char *entry_name)
{
        struct boot_dev *entry;

        entry = (struct boot_dev *)calloc(1, sizeof (struct boot_dev));

        if (entry == NULL) {
                return (NULL);
        }
        if ((entry->bootdev_element = strdup(entry_name)) == NULL) {
                free(entry);
                return (NULL);
        }
        /*
         * Allocate room for 1 name and a null terminator - the caller of
         * this function will need the first slot right away.
         */
        if ((entry->bootdev_trans = (char **)calloc(2, sizeof (char *)))
            == NULL) {
                free(entry->bootdev_element);
                free(entry);
                return (NULL);
        }
        return (entry);
}

/*
 * will come back with a concatenated list of paths
 */
int
devfs_dev_to_prom_names(char *dev_path, char *prom_path, size_t len)
{
        Oppbuf oppbuf;
        struct openpromio *opp = &(oppbuf.opp);
        int prom_fd;
        int ret = DEVFS_INVAL;
        int i;

        if (prom_path == NULL) {
                return (DEVFS_INVAL);
        }
        if (dev_path == NULL) {
                return (DEVFS_INVAL);
        }
        if (strlen(dev_path) >= MAXPATHLEN)
                return (DEVFS_INVAL);

        if (*dev_path != '/')
                return (DEVFS_INVAL);

        prom_fd = prom_open(O_RDONLY);
        if (prom_fd < 0) {
                return (prom_fd);
        }

        /* query the prom */
        (void) snprintf(opp->oprom_array, MAXVALSIZE, "%s", dev_path);
        opp->oprom_size = MAXVALSIZE;

        if (ioctl(prom_fd, OPROMDEV2PROMNAME, opp) == 0) {
                prom_close(prom_fd);

                /* return the prom path in prom_path */

                i = len - opp->oprom_size;
                if (i < 0) {
                        bcopy(opp->oprom_array, prom_path, len);
                        prom_path[len - 1] = '\0';
                        return (len);
                } else {
                        bcopy(opp->oprom_array, prom_path, len);
                        return (opp->oprom_size);
                }
        }
        /*
         * either the prom does not support this ioctl or the argument
         * was invalid.
         */
        if (errno == ENXIO) {
                ret = DEVFS_NOTSUP;
        }
        prom_close(prom_fd);
        return (ret);
}

/*
 * Convert a physical or logical device name to a name the prom would
 * understand.  Fail if this platform does not support a prom or if
 * the device does not correspond to a valid prom device.
 *      dev_path should be the name of a device in the logical or
 *              physical device namespace.
 *      prom_path is the prom version of the device name
 *      prom_path must be large enough to contain the result and is
 *      supplied by the user.
 *
 * This routine only supports converting leaf device paths
 */
int
devfs_dev_to_prom_name(char *dev_path, char *prom_path)
{
        int rval;

        rval = devfs_dev_to_prom_names(dev_path, prom_path, MAXPATHLEN);

        if (rval < 0)
                return (rval);
        else
                return (0);
}

/*
 * Use the openprom driver's OPROMPATH2DRV ioctl to convert a devfs
 * path to a driver name.
 * devfs_path - the pathname of interest.  This must be the physcical device
 * path with the mount point prefix (ie. /devices) stripped off.
 * drv_buf - user supplied buffer - the driver name will be stored here.
 *
 * If the prom lookup fails, we return the name of the last component in
 * the pathname.  This routine is useful for looking up driver names
 * associated with generically named devices.
 *
 * This routine returns driver names that have aliases resolved.
 */
int
devfs_path_to_drv(char *devfs_path, char *drv_buf)
{
        Oppbuf oppbuf;
        struct openpromio *opp = &(oppbuf.opp);
        char *slash, *colon, *dev_addr;
        char driver_path[MAXPATHLEN];
        int prom_fd;

        if (drv_buf == NULL) {
                return (-1);
        }
        if (devfs_path == NULL) {
                return (-1);
        }

        if (strlen(devfs_path) >= MAXPATHLEN)
                return (-1);

        if (*devfs_path != '/')
                return (-1);


        /* strip off any minor node info at the end of the path */
        (void) strcpy(driver_path, devfs_path);
        slash = strrchr(driver_path, '/');
        if (slash == NULL)
                return (-1);
        colon = strrchr(slash, ':');
        if (colon != NULL)
                *colon = '\0';

        /* query the prom */
        if ((prom_fd = prom_open(O_RDONLY)) >= 0) {
                (void) strcpy(opp->oprom_array, driver_path);
                opp->oprom_size = MAXVALSIZE;

                if (ioctl(prom_fd, OPROMPATH2DRV, opp) == 0) {
                        prom_close(prom_fd);
                        /* return the driver name in drv_buf */
                        (void) strcpy(drv_buf, opp->oprom_array);
                        return (0);
                }
                prom_close(prom_fd);
        } else if (prom_fd != DEVFS_NOTSUP)
                return (-1);
        /*
         * If we get here, then either:
         *      1. this platform does not support an openprom driver
         *      2. we were asked to look up a device the prom does
         *         not know about (e.g. a pseudo device)
         * In this case, we use the last component of the devfs path
         * name and try to derive the driver name
         */

        /* use the last component of devfs_path as the driver name */
        if ((dev_addr = strrchr(slash, '@')) != NULL)
                *dev_addr = '\0';
        slash++;

        /* use opp->oprom_array as a buffer */
        (void) strcpy(opp->oprom_array, slash);
        if (devfs_resolve_aliases(opp->oprom_array) == NULL)
                return (-1);
        (void) strcpy(drv_buf, opp->oprom_array);
        return (0);
}

/*
 * These modctl calls do the equivalent of:
 *      ddi_name_to_major()
 *      ddi_major_to_name()
 * This results in two things:
 *      - the driver name must be a valid one
 *      - any driver aliases are resolved.
 * drv is overwritten with the resulting name.
 */
char *
devfs_resolve_aliases(char *drv)
{
        major_t maj;
        char driver_name[MAXNAMELEN + 1];

        if (drv == NULL) {
                return (NULL);
        }

        if (modctl(MODGETMAJBIND, drv, strlen(drv) + 1, &maj) < 0)
                return (NULL);
        else if (modctl(MODGETNAME, driver_name, sizeof (driver_name), &maj)
            < 0) {
                return (NULL);
        } else {
                (void) strcpy(drv, driver_name);
                return (drv);
        }
}

/*
 * open the openprom device.  and verify that we are on an
 * OBP/1275 OF machine.  If the prom does not exist, then we
 * return an error
 */
static int
prom_open(int oflag)
{
        int prom_fd = -1;
        char *promdev = "/dev/openprom";

        while (prom_fd < 0) {
                if ((prom_fd = open(promdev, oflag)) < 0)  {
                        if (errno == EAGAIN)   {
                                (void) sleep(5);
                                continue;
                        }
                        if ((errno == ENXIO) || (errno == ENOENT)) {
                                return (DEVFS_NOTSUP);
                        }
                        if ((errno == EPERM) || (errno == EACCES)) {
                                return (DEVFS_PERM);
                        }
                        return (DEVFS_ERR);
                } else
                        break;
        }
        if (is_openprom(prom_fd))
                return (prom_fd);
        else {
                prom_close(prom_fd);
                return (DEVFS_ERR);
        }
}

static void
prom_close(int prom_fd)
{
        (void) close(prom_fd);
}

/*
 * is this an OBP/1275 OF machine?
 */
static int
is_openprom(int prom_fd)
{
        Oppbuf  oppbuf;
        struct openpromio *opp = &(oppbuf.opp);
        unsigned int i;

        opp->oprom_size = MAXVALSIZE;
        if (ioctl(prom_fd, OPROMGETCONS, opp) < 0)
                return (0);

        i = (unsigned int)((unsigned char)opp->oprom_array[0]);
        return ((i & OPROMCONS_OPENPROM) == OPROMCONS_OPENPROM);
}

/*
 * convert a prom device path name to an equivalent physical device
 * path in the kernel.
 */
static int
devfs_prom_to_dev_name(char *prom_path, char *dev_path)
{
        Oppbuf oppbuf;
        struct openpromio *opp = &(oppbuf.opp);
        int prom_fd;
        int ret = DEVFS_INVAL;

        if (dev_path == NULL) {
                return (DEVFS_INVAL);
        }
        if (prom_path == NULL) {
                return (DEVFS_INVAL);
        }
        if (strlen(prom_path) >= MAXPATHLEN)
                return (DEVFS_INVAL);

        if (*prom_path != '/') {
                return (DEVFS_INVAL);
        }

        /* query the prom */
        prom_fd = prom_open(O_RDONLY);
        if (prom_fd < 0) {
                return (prom_fd);
        }
        (void) strcpy(opp->oprom_array, prom_path);
        opp->oprom_size = MAXVALSIZE;

        if (ioctl(prom_fd, OPROMPROM2DEVNAME, opp) == 0) {
                prom_close(prom_fd);
                /*
                 * success
                 * return the prom path in prom_path
                 */
                (void) strcpy(dev_path, opp->oprom_array);
                return (0);
        }
        /*
         * either the argument was not a valid name or the openprom
         * driver does not support this ioctl.
         */
        if (errno == ENXIO) {
                ret = DEVFS_NOTSUP;
        }
        prom_close(prom_fd);
        return (ret);
}
/*
 * convert a prom device path to a list of equivalent alias names
 * If there is no alias node, or there are no aliases that correspond
 * to dev, we return empty lists.
 */
static int
prom_dev_to_alias(char *dev, uint_t options, char ***ret_buf)
{
        struct name_list *exact_list;
        struct name_list *inexact_list;
        struct name_list *list;
        char *ptr;
        char **array;
        int prom_fd;
        int count;
        int vers;

        vers = prom_obp_vers();
        if (vers < 0) {
                return (vers);
        }

        if (dev == NULL) {
                return (DEVFS_INVAL);
        }

        if (*dev != '/')
                return (DEVFS_INVAL);

        if (strlen(dev) >= MAXPATHLEN)
                return (DEVFS_INVAL);

        if ((ptr = strchr(dev, ':')) != NULL) {
                if (strchr(ptr, '/') != NULL)
                        return (DEVFS_INVAL);
        }
        if (ret_buf == NULL) {
                return (DEVFS_INVAL);
        }

        prom_fd = prom_open(O_RDONLY);
        if (prom_fd < 0) {
                return (prom_fd);
        }

        (void) prom_srch_aliases_by_def(dev, &exact_list,
            &inexact_list,  prom_fd);

        prom_close(prom_fd);

        if ((options & BOOTDEV_NO_EXACT_ALIAS) != 0) {
                free_name_list(exact_list, 1);
                exact_list = NULL;
        }

        if ((options & BOOTDEV_NO_INEXACT_ALIAS) != 0) {
                free_name_list(inexact_list, 1);
                inexact_list = NULL;
        }

        count = 0;
        list = exact_list;
        while (list != NULL) {
                list = list->next;
                count++;
        }
        list = inexact_list;
        while (list != NULL) {
                list = list->next;
                count++;
        }

        if ((*ret_buf = (char **)malloc((count + 1) * sizeof (char *)))
            == NULL) {
                free_name_list(inexact_list, 1);
                free_name_list(exact_list, 1);
                return (DEVFS_NOMEM);
        }

        array = *ret_buf;
        count = 0;
        list = exact_list;
        while (list != NULL) {
                array[count] = list->name;
                list = list->next;
                count++;
        }
        list = inexact_list;
        while (list != NULL) {
                array[count] = list->name;
                list = list->next;
                count++;
        }
        array[count] = NULL;
        free_name_list(inexact_list, 0);
        free_name_list(exact_list, 0);

        return (0);
}

/*
 * determine the version of prom we are running on.
 * Also include any prom revision specific information.
 */
static int
prom_obp_vers(void)
{
        Oppbuf  oppbuf;
        struct openpromio *opp = &(oppbuf.opp);
        int prom_fd;
        static int version = 0;

        /* cache version */
        if (version > 0) {
                return (version);
        }

        prom_fd = prom_open(O_RDONLY);
        if (prom_fd < 0) {
                return (prom_fd);
        }

        opp->oprom_size = MAXVALSIZE;

        if ((ioctl(prom_fd, OPROMGETVERSION, opp)) < 0) {
                prom_close(prom_fd);
                return (DEVFS_ERR);
        }
        prom_close(prom_fd);

        version |= OBP_OF;

        return (version);
}
/*
 * search the aliases node by definition - compile a list of
 * alias names that are both exact and inexact matches.
 */
static int
prom_srch_aliases_by_def(char *promdev_def, struct name_list **exact_list,
    struct name_list **inexact_list, int prom_fd)
{
        Oppbuf  oppbuf;
        Oppbuf  propdef_oppbuf;
        struct openpromio *opp = &(oppbuf.opp);
        struct openpromio *propdef_opp = &(propdef_oppbuf.opp);
        int *ip = (int *)((void *)opp->oprom_array);
        int ret;
        struct name_list *inexact_match = *inexact_list = NULL;
        struct name_list *exact_match = *exact_list = NULL;
        char alias_buf[MAXNAMELEN];
        int found = 0;

        if ((ret = prom_find_aliases_node(prom_fd)) < 0)
                return (0);

        (void) memset(oppbuf.buf, 0, BUFSIZE);
        opp->oprom_size = MAXPROPSIZE;
        *ip = 0;

        if ((ret = ioctl(prom_fd, OPROMNXTPROP, opp)) < 0)
                return (0);
        if (opp->oprom_size == 0)
                return (0);

        while ((ret >= 0) && (opp->oprom_size > 0)) {
                (void) strcpy(propdef_opp->oprom_array, opp->oprom_array);
                opp->oprom_size = MAXPROPSIZE;
                propdef_opp->oprom_size = MAXVALSIZE;
                if ((ioctl(prom_fd, OPROMGETPROP, propdef_opp) < 0) ||
                    (propdef_opp->oprom_size == 0)) {
                        ret = ioctl(prom_fd, OPROMNXTPROP, opp);
                        continue;
                }
                ret = prom_compare_devs(promdev_def, propdef_opp->oprom_array);
                if (ret == EXACT_MATCH) {
                        found++;
                        if (insert_alias_list(exact_list, opp->oprom_array)
                            != 0) {
                                free_name_list(exact_match, 1);
                                free_name_list(inexact_match, 1);
                                return (-1);
                        }
                }
                if (ret == INEXACT_MATCH) {
                        found++;
                        (void) strcpy(alias_buf, opp->oprom_array);
                        options_override(promdev_def, alias_buf);
                        if (insert_alias_list(inexact_list, alias_buf)
                            != 0) {
                                free_name_list(exact_match, 1);
                                free_name_list(inexact_match, 1);
                                return (-1);
                        }
                }
                ret = ioctl(prom_fd, OPROMNXTPROP, opp);
        }
        if (found) {
                return (0);
        } else {
                return (-1);
        }
}

/*
 * free a list of name_list structs and optionally
 * free the strings they contain.
 */
static void
free_name_list(struct name_list *list, int free_name)
{
        struct name_list *next = list;

        while (next != NULL) {
                list = list->next;
                if (free_name)
                        free(next->name);
                free(next);
                next = list;
        }
}

/*
 * insert a new alias in a list of aliases - the list is sorted
 * in collating order (ignoring anything that comes after the
 * ':' in the name).
 */
static int
insert_alias_list(struct name_list **list, char *alias_name)
{
        struct name_list *entry = *list;
        struct name_list *new_entry, *prev_entry;
        int ret;
        char *colon1, *colon2;

        if ((new_entry =
            (struct name_list *)malloc(sizeof (struct name_list)))
            == NULL) {
                return (-1);
        }
        if ((new_entry->name = strdup(alias_name)) == NULL) {
                free(new_entry);
                return (-1);
        }
        new_entry->next = NULL;

        if (entry == NULL) {
                *list = new_entry;
                return (0);
        }

        if ((colon1 = strchr(alias_name, ':')) != NULL) {
                *colon1 = '\0';
        }
        prev_entry = NULL;
        while (entry != NULL) {
                if ((colon2 = strchr(entry->name, ':')) != NULL) {
                        *colon2 = '\0';
                }
                ret = strcmp(alias_name, entry->name);
                if (colon2 != NULL) {
                        *colon2 = ':';
                }
                /* duplicate */
                if (ret == 0) {
                        free(new_entry->name);
                        free(new_entry);
                        if (colon1 != NULL) {
                                *colon1 = ':';
                        }
                        return (0);
                }
                if (ret < 0) {
                        new_entry->next = entry;
                        if (prev_entry == NULL) {
                                /* in beginning of list */
                                *list = new_entry;
                        } else {
                                /* in middle of list */
                                prev_entry->next = new_entry;
                        }
                        if (colon1 != NULL) {
                                *colon1 = ':';
                        }
                        return (0);
                }
                prev_entry = entry;
                entry = entry->next;
        }
        /* at end of list */
        prev_entry->next = new_entry;
        new_entry->next = NULL;
        if (colon1 != NULL) {
                *colon1 = ':';
        }
        return (0);
}
/*
 * append :x to alias_name to override any default minor name options
 */
static void
options_override(char *prom_path, char *alias_name)
{
        char *colon;

        if ((colon = strrchr(alias_name, ':')) != NULL) {
                /*
                 * XXX - should alias names in /aliases ever have a
                 * : embedded in them?
                 * If so we ignore it.
                 */
                *colon = '\0';
        }

        if ((colon = strrchr(prom_path, ':')) != NULL) {
                (void) strcat(alias_name, colon);
        }
}

/*
 * compare to prom device names.
 * if the device names are not fully qualified. we convert them -
 * we only do this as a last resort though since it requires
 * jumping into the kernel.
 */
static int
prom_compare_devs(char *prom_dev1, char *prom_dev2)
{
        char *dev1, *dev2;
        char *ptr1, *ptr2;
        char *drvname1, *addrname1, *minorname1;
        char *drvname2, *addrname2, *minorname2;
        char component1[MAXNAMELEN], component2[MAXNAMELEN];
        char devname1[MAXPATHLEN], devname2[MAXPATHLEN];
        int unqualified_name = 0;
        int error = EXACT_MATCH;
        int len1, len2;
        char *wildcard = ",0";

        ptr1 = prom_dev1;
        ptr2 = prom_dev2;

        if ((ptr1 == NULL) || (*ptr1 != '/')) {
                return (NO_MATCH);
        }
        if ((ptr2 == NULL) || (*ptr2 != '/')) {
                return (NO_MATCH);
        }

        /*
         * compare device names one component at a time.
         */
        while ((ptr1 != NULL) && (ptr2 != NULL)) {
                *ptr1 = *ptr2 = '/';
                dev1 = ptr1 + 1;
                dev2 = ptr2 + 1;
                if ((ptr1 = strchr(dev1, '/')) != NULL)
                        *ptr1 = '\0';
                if ((ptr2 = strchr(dev2, '/')) != NULL)
                        *ptr2 = '\0';

                (void) strcpy(component1, dev1);
                (void) strcpy(component2, dev2);

                parse_name(component1, &drvname1, &addrname1, &minorname1);
                parse_name(component2, &drvname2, &addrname2, &minorname2);

                if ((drvname1 == NULL) && (addrname1 == NULL)) {
                        error = NO_MATCH;
                        break;
                }

                if ((drvname2 == NULL) && (addrname2 == NULL)) {
                        error = NO_MATCH;
                        break;
                }

                if (_prom_strcmp(drvname1, drvname2) != 0) {
                        error = NO_MATCH;
                        break;
                }

                /*
                 * a possible name is driver_name@address.  The address
                 * portion is optional (i.e. the name is not fully
                 * qualified.).  We have to deal with the case where
                 * the component name is either driver_name or
                 * driver_name@address
                 */
                if ((addrname1 == NULL) ^ (addrname2 == NULL)) {
                        unqualified_name = 1;
                } else if (addrname1 &&
                    (_prom_strcmp(addrname1, addrname2) != 0)) {
                        /*
                         * check to see if appending a ",0" to the
                         * shorter address causes a match to occur.
                         * If so succeed.
                         */
                        len1 = strlen(addrname1);
                        len2 = strlen(addrname2);
                        if ((len1 < len2) &&
                            (strncmp(addrname1, addrname2, len1) == 0) &&
                            (strcmp(wildcard, &addrname2[len1]) == 0)) {
                                continue;
                        } else if ((len2 < len1) &&
                            (strncmp(addrname1, addrname2, len2) == 0) &&
                            (strcmp(wildcard, &addrname1[len2]) == 0)) {
                                continue;
                        }
                        error = NO_MATCH;
                        break;
                }
        }

        /*
         * if either of the two device paths still has more components,
         * then we do not have a match.
         */
        if (ptr1 != NULL) {
                *ptr1 = '/';
                error = NO_MATCH;
        }
        if (ptr2 != NULL) {
                *ptr2 = '/';
                error = NO_MATCH;
        }
        if (error == NO_MATCH) {
                return (error);
        }

        /*
         * OK - we found a possible match but one or more of the
         * path components was not fully qualified (did not have any
         * address information.  So we need to convert it to a form
         * that is fully qualified and then compare the resulting
         * strings.
         */
        if (unqualified_name != 0) {
                if ((devfs_prom_to_dev_name(prom_dev1, devname1) < 0) ||
                    (devfs_prom_to_dev_name(prom_dev2, devname2) < 0)) {
                        return (NO_MATCH);
                }
                if ((dev1 = strrchr(devname1, ':')) != NULL) {
                        *dev1 = '\0';
                }
                if ((dev2 = strrchr(devname2, ':')) != NULL) {
                        *dev2 = '\0';
                }
                if (strcmp(devname1, devname2) != 0) {
                        return (NO_MATCH);
                }
        }
        /*
         * the resulting strings matched.  If the minorname information
         * matches, then we have an exact match, otherwise an inexact match
         */
        if (_prom_strcmp(minorname1, minorname2) == 0) {
                return (EXACT_MATCH);
        } else {
                return (INEXACT_MATCH);
        }
}

/*
 * wrapper or strcmp - deals with null strings.
 */
static int
_prom_strcmp(char *s1, char *s2)
{
        if ((s1 == NULL) && (s2 == NULL))
                return (0);
        if ((s1 == NULL) && (s2 != NULL)) {
                return (-1);
        }
        if ((s1 != NULL) && (s2 == NULL)) {
                return (1);
        }
        return (strcmp(s1, s2));
}
/*
 * break device@a,b:minor into components
 */
static void
parse_name(char *name, char **drvname, char **addrname, char **minorname)
{
        char *cp, ch;

        cp = *drvname = name;
        *addrname = *minorname = NULL;
        if (*name == '@')
                *drvname = NULL;

        while ((ch = *cp) != '\0') {
                if (ch == '@')
                        *addrname = ++cp;
                else if (ch == ':')
                        *minorname = ++cp;
                ++cp;
        }
        if (*addrname) {
                *((*addrname)-1) = '\0';
        }
        if (*minorname) {
                *((*minorname)-1) = '\0';
        }
}

/*
 * converts a prom alias to a prom device name.
 * if we find no matching device, then we fail since if were
 * given a valid alias, then by definition, there must be a
 * device pathname associated with it in the /aliases node.
 */
static int
alias_to_prom_dev(char *alias, char *ret_buf)
{
        char *options_ptr;
        char alias_buf[MAXNAMELEN];
        char alias_def[MAXPATHLEN];
        char options[16] = "";
        int prom_fd = -1;
        int ret;
        int i;

        if (strchr(alias, '/') != NULL)
                return (DEVFS_INVAL);

        if (strlen(alias) > (MAXNAMELEN - 1))
                return (DEVFS_INVAL);

        if (ret_buf == NULL) {
                return (DEVFS_INVAL);
        }

        prom_fd = prom_open(O_RDONLY);
        if (prom_fd < 0) {
                return (prom_fd);
        }

        (void) strlcpy(alias_buf, alias, sizeof (alias_buf));

        /*
         * save off any options (minor name info) that is
         * explicitly called out in the alias name
         */
        if ((options_ptr = strchr(alias_buf, ':')) != NULL) {
                *options_ptr = '\0';
                (void) strlcpy(options, ++options_ptr, sizeof (options));
        }

        *alias_def = '\0';

        ret = prom_find_aliases_node(prom_fd);
        if (ret == 0) {
                /*
                 * we loop because one alias may define another... we have
                 * to work our way down to an actual device definition.
                 */
                for (i = 0; i <= 10; i++) {
                        ret = prom_srch_node(prom_fd, alias_buf, alias_def);
                        if (ret == -1) {
                                break;
                        }
                        (void) strlcpy(alias_buf, alias_def,
                            sizeof (alias_buf));
                        if (*alias_def == '/') {
                                break;
                        }

                        /*
                         * save off any explicit options (minor name info)
                         * if none has been encountered yet
                         */
                        if (options_ptr == NULL) {
                                options_ptr = strchr(alias_buf, ':');
                                if (options_ptr != NULL) {
                                        *options_ptr = '\0';
                                        (void) strlcpy(options, ++options_ptr,
                                            sizeof (options));
                                }
                        }
                }
        }
        prom_close(prom_fd);

        /* error */
        if (ret == -1) {
                return (ret);
        }

        (void) strlcpy(ret_buf, alias_def, MAXPATHLEN);

        /* override minor name information */
        if (options_ptr != NULL) {
                if ((options_ptr = strrchr(ret_buf, ':')) == NULL) {
                        (void) strcat(ret_buf, ":");
                } else {
                        *(++options_ptr) = '\0';
                }
                (void) strcat(ret_buf, options);
        }
        return (0);
}

/*
 * search a prom node for a property name
 */
static int
prom_srch_node(int fd, char *prop_name, char *ret_buf)
{
        Oppbuf  oppbuf;
        struct openpromio *opp = &(oppbuf.opp);
        int *ip = (int *)((void *)opp->oprom_array);

        (void) memset(oppbuf.buf, 0, BUFSIZE);
        opp->oprom_size = MAXPROPSIZE;
        *ip = 0;

        if (ioctl(fd, OPROMNXTPROP, opp) < 0)
                return (-1);
        if (opp->oprom_size == 0)
                return (-1);

        while (strcmp(prop_name, opp->oprom_array) != 0) {
                opp->oprom_size = MAXPROPSIZE;
                if (ioctl(fd, OPROMNXTPROP, opp) < 0)
                        return (-1);
                if (opp->oprom_size == 0)
                        return (-1);
        }
        opp->oprom_size = MAXVALSIZE;
        if (ioctl(fd, OPROMGETPROP, opp) < 0)
                return (-1);

        if (opp->oprom_size == 0)
                return (-1);
        (void) strlcpy(ret_buf, opp->oprom_array, MAXPATHLEN);
        return (0);
}

/*
 * return the aliases node.
 */
static int
prom_find_aliases_node(int fd)
{
        uint_t child_id;
        char buf[MAXPATHLEN];

        if ((child_id = prom_next_node(fd, 0)) == 0)
                return (-1);
        if ((child_id = prom_child_node(fd, child_id)) == 0)
                return (-1);

        while (child_id != 0) {
                if (prom_srch_node(fd, "name", buf) == 0) {
                        if (strcmp(buf, "aliases") == 0) {
                                return (0);
                        }
                }
                child_id = prom_next_node(fd, child_id);
        }
        return (-1);
}

/*
 * get sibling
 */
static uint_t
prom_next_node(int fd, uint_t node_id)
{
        Oppbuf  oppbuf;
        struct openpromio *opp = &(oppbuf.opp);
        uint_t *ip = (uint_t *)((void *)opp->oprom_array);

        (void) memset(oppbuf.buf, 0, BUFSIZE);
        opp->oprom_size = MAXVALSIZE;
        *ip = node_id;

        if (ioctl(fd, OPROMNEXT, opp) < 0)
                return (0);

        return (*(uint_t *)((void *)opp->oprom_array));
}

/*
 * get child
 */
static uint_t
prom_child_node(int fd, uint_t node_id)
{
        Oppbuf  oppbuf;
        struct openpromio *opp = &(oppbuf.opp);
        uint_t *ip = (uint_t *)((void *)opp->oprom_array);

        (void) memset(oppbuf.buf, 0, BUFSIZE);
        opp->oprom_size = MAXVALSIZE;
        *ip = node_id;

        if (ioctl(fd, OPROMCHILD, opp) < 0)
                return (0);

        return (*(uint_t *)((void *)opp->oprom_array));
}

/*
 * only on sparc for now
 */
int
devfs_bootdev_modifiable(void)
{
#if defined(sparc)
        return (0);
#else
        return (DEVFS_NOTSUP);
#endif
}