/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (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 2004 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * Copyright 2019 Joyent, Inc.
 */

#include <sys/types.h>
#include <sys/sysmacros.h>
#include <sys/dditypes.h>
#include <sys/ddi_impldefs.h>
#include <sys/ddipropdefs.h>
#include <sys/modctl.h>
#include <sys/file.h>
#include <sys/sunldi_impl.h>

#include <mdb/mdb_modapi.h>
#include <mdb/mdb_ks.h>

#include "ldi.h"

/*
 * ldi handle walker structure
 */
typedef struct lh_walk {
        struct ldi_handle       **hash; /* current bucket pointer       */
        struct ldi_handle       *lhp;   /* ldi handle pointer           */
        size_t                  index;  /* hash table index             */
        struct ldi_handle       buf;    /* buffer used for handle reads */
} lh_walk_t;

/*
 * ldi identifier walker structure
 */
typedef struct li_walk {
        struct ldi_ident        **hash; /* current bucket pointer       */
        struct ldi_ident        *lip;   /* ldi handle pointer           */
        size_t                  index;  /* hash table index             */
        struct ldi_ident        buf;    /* buffer used for ident reads */
} li_walk_t;

/*
 * Options for ldi_handles dcmd
 */
#define LH_IDENTINFO    0x1

/*
 * LDI walkers
 */
int
ldi_handle_walk_init(mdb_walk_state_t *wsp)
{
        lh_walk_t       *lhwp;
        GElf_Sym        sym;

        /* get the address of the hash table */
        if (mdb_lookup_by_name("ldi_handle_hash", &sym) == -1) {
                mdb_warn("couldn't find ldi_handle_hash");
                return (WALK_ERR);
        }

        lhwp = mdb_alloc(sizeof (lh_walk_t), UM_SLEEP|UM_GC);
        lhwp->hash = (struct ldi_handle **)(uintptr_t)sym.st_value;
        lhwp->index = 0;

        /* get the address of the first element in the first hash bucket */
        if ((mdb_vread(&lhwp->lhp, sizeof (struct ldi_handle *),
            (uintptr_t)lhwp->hash)) == -1) {
                mdb_warn("couldn't read ldi handle hash at %p", lhwp->hash);
                return (WALK_ERR);
        }

        wsp->walk_addr = (uintptr_t)lhwp->lhp;
        wsp->walk_data = lhwp;

        return (WALK_NEXT);
}

int
ldi_handle_walk_step(mdb_walk_state_t *wsp)
{
        lh_walk_t       *lhwp = (lh_walk_t *)wsp->walk_data;
        int             status;

        /* check if we need to go to the next hash bucket */
        while (wsp->walk_addr == 0) {

                /* advance to the next bucket */
                if (++(lhwp->index) >= LH_HASH_SZ)
                        return (WALK_DONE);

                /* get handle address from the hash bucket */
                if ((mdb_vread(&lhwp->lhp, sizeof (struct ldi_handle *),
                    (uintptr_t)(lhwp->hash + lhwp->index))) == -1) {
                        mdb_warn("couldn't read ldi handle hash at %p",
                            (uintptr_t)lhwp->hash + lhwp->index);
                        return (WALK_ERR);
                }

                wsp->walk_addr = (uintptr_t)lhwp->lhp;
        }

        /* invoke the walker callback for this hash element */
        status = wsp->walk_callback(wsp->walk_addr, NULL, wsp->walk_cbdata);
        if (status != WALK_NEXT)
                return (status);

        /* get a pointer to the next hash element */
        if (mdb_vread(&lhwp->buf, sizeof (struct ldi_handle),
            wsp->walk_addr) == -1) {
                mdb_warn("couldn't read ldi handle at %p", wsp->walk_addr);
                return (WALK_ERR);
        }
        wsp->walk_addr = (uintptr_t)lhwp->buf.lh_next;
        return (WALK_NEXT);
}

int
ldi_ident_walk_init(mdb_walk_state_t *wsp)
{
        li_walk_t       *liwp;
        GElf_Sym        sym;

        /* get the address of the hash table */
        if (mdb_lookup_by_name("ldi_ident_hash", &sym) == -1) {
                mdb_warn("couldn't find ldi_ident_hash");
                return (WALK_ERR);
        }

        liwp = mdb_alloc(sizeof (li_walk_t), UM_SLEEP|UM_GC);
        liwp->hash = (struct ldi_ident **)(uintptr_t)sym.st_value;
        liwp->index = 0;

        /* get the address of the first element in the first hash bucket */
        if ((mdb_vread(&liwp->lip, sizeof (struct ldi_ident *),
            (uintptr_t)liwp->hash)) == -1) {
                mdb_warn("couldn't read ldi ident hash at %p", liwp->hash);
                return (WALK_ERR);
        }

        wsp->walk_addr = (uintptr_t)liwp->lip;
        wsp->walk_data = liwp;

        return (WALK_NEXT);
}

int
ldi_ident_walk_step(mdb_walk_state_t *wsp)
{
        li_walk_t       *liwp = (li_walk_t *)wsp->walk_data;
        int             status;

        /* check if we need to go to the next hash bucket */
        while (wsp->walk_addr == 0) {

                /* advance to the next bucket */
                if (++(liwp->index) >= LI_HASH_SZ)
                        return (WALK_DONE);

                /* get handle address from the hash bucket */
                if ((mdb_vread(&liwp->lip, sizeof (struct ldi_ident *),
                    (uintptr_t)(liwp->hash + liwp->index))) == -1) {
                        mdb_warn("couldn't read ldi ident hash at %p",
                            (uintptr_t)liwp->hash + liwp->index);
                        return (WALK_ERR);
                }

                wsp->walk_addr = (uintptr_t)liwp->lip;
        }

        /* invoke the walker callback for this hash element */
        status = wsp->walk_callback(wsp->walk_addr, NULL, wsp->walk_cbdata);
        if (status != WALK_NEXT)
                return (status);

        /* get a pointer to the next hash element */
        if (mdb_vread(&liwp->buf, sizeof (struct ldi_ident),
            wsp->walk_addr) == -1) {
                mdb_warn("couldn't read ldi ident at %p", wsp->walk_addr);
                return (WALK_ERR);
        }
        wsp->walk_addr = (uintptr_t)liwp->buf.li_next;
        return (WALK_NEXT);
}

/*
 * LDI dcmds
 */
static void
ldi_ident_header(int start, int refs)
{
        if (start) {
                mdb_printf("%-?s ", "IDENT");
        } else {
                mdb_printf("%?s ", "IDENT");
        }

        if (refs)
                mdb_printf("%4s ", "REFS");

        mdb_printf("%?s %5s %5s %s\n", "DIP", "MINOR", "MODID", "MODULE NAME");
}

static int
ldi_ident_print(uintptr_t addr, int refs)
{
        struct ldi_ident        li;

        /* read the ldi ident */
        if (mdb_vread(&li, sizeof (struct ldi_ident), addr) == -1) {
                mdb_warn("couldn't read ldi ident at %p", addr);
                return (1);
        }

        /* display the ident address */
        mdb_printf("%0?p ", addr);

        /* display the ref count */
        if (refs)
                mdb_printf("%4u ", li.li_ref);

        /* display the dip (if any) */
        if (li.li_dip != NULL) {
                mdb_printf("%0?p ", li.li_dip);
        } else {
                mdb_printf("%?s ", "-");
        }

        /* display the minor node (if any) */
        if (li.li_dev != DDI_DEV_T_NONE) {
                mdb_printf("%5u ", getminor(li.li_dev));
        } else {
                mdb_printf("%5s ", "-");
        }

        /* display the module info */
        mdb_printf("%5d %s\n", li.li_modid, li.li_modname);

        return (0);
}

int
ldi_ident(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
{
        int     start = 1;
        int     refs = 1;

        /* Determine if there is an ldi identifier address */
        if (!(flags & DCMD_ADDRSPEC)) {
                if (mdb_walk_dcmd("ldi_ident", "ldi_ident",
                    argc, argv) == -1) {
                        mdb_warn("can't walk ldi idents");
                        return (DCMD_ERR);
                }
                return (DCMD_OK);
        }

        /* display the header line */
        if (DCMD_HDRSPEC(flags))
                ldi_ident_header(start, refs);

        /* display the ldi ident */
        if (ldi_ident_print(addr, refs))
                return (DCMD_ERR);

        return (DCMD_OK);
}

static void
ldi_handle_header(int refs, int ident)
{
        mdb_printf("%-?s ", "HANDLE");

        if (refs)
                mdb_printf("%4s ", "REFS");

        mdb_printf("%?s %10s %5s %?s ", "VNODE", "DRV", "MINOR", "EVENTS");

        if (!ident) {
                mdb_printf("%?s\n", "IDENT");
        } else {
                ldi_ident_header(0, 0);
        }
}

static int
ldi_handle_print(uintptr_t addr, int ident, int refs)
{
        vnode_t                 vnode;
        struct ldi_handle       lh;
        const char              *name;

        /* read in the ldi handle */
        if (mdb_vread(&lh, sizeof (struct ldi_handle), addr) == -1) {
                mdb_warn("couldn't read ldi handle at %p", addr);
                return (DCMD_ERR);
        }

        /* display the handle address */
        mdb_printf("%0?p ", addr);

        /* display the ref count */
        if (refs)
                mdb_printf("%4u ", lh.lh_ref);

        /* display the vnode */
        mdb_printf("%0?p ", lh.lh_vp);

        /* read in the vnode associated with the handle */
        addr = (uintptr_t)lh.lh_vp;
        if (mdb_vread(&vnode, sizeof (vnode_t), addr) == -1) {
                mdb_warn("couldn't read vnode at %p", addr);
                return (1);
        }

        /* display the driver name */
        if ((name = mdb_major_to_name(getmajor(vnode.v_rdev))) == NULL) {
                mdb_warn("failed to convert major number to name\n");
                return (1);
        }
        mdb_printf("%10s ", name);

        /* display the minor number */
        mdb_printf("%5d ", getminor(vnode.v_rdev));

        /* display the event pointer (if any) */
        if (lh.lh_events != NULL) {
                mdb_printf("%0?p ", lh.lh_events);
        } else {
                mdb_printf("%?s ", "-");
        }

        if (!ident) {
                /* display the ident address */
                mdb_printf("%0?p\n", lh.lh_ident);
                return (0);
        }

        /* display the entire ident  */
        return (ldi_ident_print((uintptr_t)lh.lh_ident, refs));
}

int
ldi_handle(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
{
        int                     ident = 0;
        int                     refs = 1;

        if (mdb_getopts(argc, argv,
            'i', MDB_OPT_SETBITS, TRUE, &ident, NULL) != argc)
                return (DCMD_USAGE);

        if (ident)
                refs = 0;

        /* Determine if there is an ldi handle address */
        if (!(flags & DCMD_ADDRSPEC)) {
                if (mdb_walk_dcmd("ldi_handle", "ldi_handle",
                    argc, argv) == -1) {
                        mdb_warn("can't walk ldi handles");
                        return (DCMD_ERR);
                }
                return (DCMD_OK);
        }

        /* display the header line */
        if (DCMD_HDRSPEC(flags))
                ldi_handle_header(refs, ident);

        /* display the ldi handle */
        if (ldi_handle_print(addr, ident, refs))
                return (DCMD_ERR);

        return (DCMD_OK);
}

void
ldi_ident_help(void)
{
        mdb_printf("Displays an ldi identifier.\n"
            "Without the address of an \"ldi_ident_t\", "
            "print all identifiers.\n"
            "With an address, print the specified identifier.\n");
}

void
ldi_handle_help(void)
{
        mdb_printf("Displays an ldi handle.\n"
            "Without the address of an \"ldi_handle_t\", "
            "print all handles.\n"
            "With an address, print the specified handle.\n\n"
            "Switches:\n"
            "  -i  print the module identifier information\n");
}