/*
 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>

/*
 * file/module function dispatcher, support, etc.
 */

#include <stand.h>
#include <string.h>
#include <sys/param.h>
#include <sys/linker.h>
#include <sys/module.h>
#include <sys/queue.h>
#include <sys/stdint.h>
#include <sys/tem_impl.h>
#include <sys/font.h>
#include <sys/sha1.h>
#include <libcrypto.h>

#include "bootstrap.h"

#if defined(EFI)
#define PTOV(pa)        ((void *)pa)
#else
#include "../i386/btx/lib/btxv86.h"
#endif

#define MDIR_REMOVED    0x0001
#define MDIR_NOHINTS    0x0002

struct moduledir {
        char    *d_path;        /* path of modules directory */
        uchar_t *d_hints;       /* content of linker.hints file */
        int     d_hintsz;       /* size of hints data */
        int     d_flags;
        STAILQ_ENTRY(moduledir) d_link;
};

static int file_load(char *, vm_offset_t, struct preloaded_file **);
static int file_load_dependencies(struct preloaded_file *);
static char *file_search(const char *, const char **);
static struct kernel_module *file_findmodule(struct preloaded_file *, char *,
    struct mod_depend *);
static int file_havepath(const char *);
static char *mod_searchmodule(char *, struct mod_depend *);
static void file_insert_tail(struct preloaded_file *);
static void file_remove(struct preloaded_file *);
struct file_metadata *metadata_next(struct file_metadata *, int);
static void moduledir_readhints(struct moduledir *);
static void moduledir_rebuild(void);

/* load address should be tweaked by first module loaded (kernel) */
static vm_offset_t loadaddr = 0;

#if defined(LOADER_FDT_SUPPORT)
static const char *default_searchpath = "/boot/kernel;/boot/modules;/boot/dtb";
#else
static const char *default_searchpath = "/platform/i86pc";
#endif

static STAILQ_HEAD(, moduledir) moduledir_list =
    STAILQ_HEAD_INITIALIZER(moduledir_list);

struct preloaded_file *preloaded_files = NULL;

static const char *kld_ext_list[] = {
        ".ko",
        "",
        ".debug",
        NULL
};


/*
 * load an object, either a disk file or code module.
 *
 * To load a file, the syntax is:
 *
 * load -t <type> <path>
 *
 * code modules are loaded as:
 *
 * load <path> <options>
 */

COMMAND_SET(load, "load", "load a kernel or module", command_load);

static int
command_load(int argc, char *argv[])
{
        char *typestr;
        int dofile, dokld, ch, error;

        dokld = dofile = 0;
        optind = 1;
        optreset = 1;
        typestr = NULL;
        if (argc == 1) {
                command_errmsg = "no filename specified";
                return (CMD_CRIT);
        }
        while ((ch = getopt(argc, argv, "kt:")) != -1) {
                switch (ch) {
                case 'k':
                        dokld = 1;
                        break;
                case 't':
                        typestr = optarg;
                        dofile = 1;
                        break;
                case '?':
                default:
                        /* getopt has already reported an error */
                        return (CMD_OK);
                }
        }
        argv += (optind - 1);
        argc -= (optind - 1);

        printf("Loading %s...\n", argv[1]);
        /*
         * Request to load a raw file?
         */
        if (dofile) {
                struct preloaded_file *fp;

                if ((typestr == NULL) || (*typestr == 0)) {
                        command_errmsg = "invalid load type";
                        return (CMD_CRIT);
                }

                if (file_findfile(argv[1], typestr) != NULL) {
                        (void) snprintf(command_errbuf, sizeof (command_errbuf),
                            "warning: file '%s' already loaded", argv[1]);
                        return (CMD_WARN);
                }

                fp = file_loadraw(argv[1], typestr, argc - 2, argv + 2, 1);
                if (fp != NULL)
                        return (CMD_OK);

                /* Failing to load mfs_root is never going to end well! */
                if (strcmp("mfs_root", typestr) == 0)
                        return (CMD_FATAL);

                return (CMD_ERROR);
        }
        /*
         * Do we have explicit KLD load ?
         */
        if (dokld || file_havepath(argv[1])) {
                error = mod_loadkld(argv[1], argc - 2, argv + 2);
                if (error == EEXIST) {
                        (void) snprintf(command_errbuf, sizeof (command_errbuf),
                            "warning: KLD '%s' already loaded", argv[1]);
                        return (CMD_WARN);
                }

                return (error == 0 ? CMD_OK : CMD_CRIT);
        }
        /*
         * Looks like a request for a module.
         */
        error = mod_load(argv[1], NULL, argc - 2, argv + 2);
        if (error == EEXIST) {
                (void) snprintf(command_errbuf, sizeof (command_errbuf),
                    "warning: module '%s' already loaded", argv[1]);
                return (CMD_WARN);
        }

        return (error == 0 ? CMD_OK : CMD_CRIT);
}

void
unload(void)
{
        struct preloaded_file *fp;

        while (preloaded_files != NULL) {
                fp = preloaded_files;
                preloaded_files = preloaded_files->f_next;
                file_discard(fp);
        }
        loadaddr = 0;
        (void) unsetenv("kernelname");
}

COMMAND_SET(unload, "unload", "unload all modules", command_unload);

static int
command_unload(int argc __unused, char *argv[] __unused)
{
        unload();
        return (CMD_OK);
}

COMMAND_SET(lsmod, "lsmod", "list loaded modules", command_lsmod);

static int
command_lsmod(int argc, char *argv[])
{
        struct preloaded_file *fp;
        struct kernel_module *mp;
        struct file_metadata *md;
        char lbuf[80];
        int ch, verbose, hash, ret = 0;

        verbose = 0;
        hash = 0;
        optind = 1;
        optreset = 1;
        while ((ch = getopt(argc, argv, "vs")) != -1) {
                switch (ch) {
                case 'v':
                        verbose = 1;
                        break;
                case 's':
                        hash = 1;
                        break;
                case '?':
                default:
                        /* getopt has already reported an error */
                        return (CMD_OK);
                }
        }

        pager_open();
        for (fp = preloaded_files; fp; fp = fp->f_next) {
                (void) snprintf(lbuf, sizeof (lbuf), " %p: ",
                    (void *) fp->f_addr);
                (void) pager_output(lbuf);
                (void) pager_output(fp->f_name);
                (void) snprintf(lbuf, sizeof (lbuf), " (%s, 0x%lx)\n",
                    fp->f_type, (long)fp->f_size);
                if (pager_output(lbuf))
                        break;
                if (fp->f_args != NULL) {
                        (void) pager_output("    args: ");
                        (void) pager_output(fp->f_args);
                        if (pager_output("\n"))
                                break;
                        if (strcmp(fp->f_type, "hash") == 0) {
                                size_t dsize;

                                (void) pager_output("    contents: ");
                                dsize = fp->f_size + 1;
                                if (sizeof (lbuf) < dsize)
                                        dsize = sizeof (lbuf);
                                (void) strlcpy(lbuf, ptov(fp->f_addr), dsize);
                                if (pager_output(lbuf))
                                        break;
                        }
                }

                if (hash == 1) {
                        void *ptr = PTOV(fp->f_addr);

                        (void) pager_output("  hash: ");
                        sha1(ptr, fp->f_size, (uint8_t *)lbuf);
                        for (int i = 0; i < SHA1_DIGEST_LENGTH; i++)
                                printf("%02x", (int)(lbuf[i] & 0xff));
                        if (pager_output("\n"))
                                break;
                }

                if (fp->f_modules) {
                        (void) pager_output("  modules: ");
                        for (mp = fp->f_modules; mp; mp = mp->m_next) {
                                (void) snprintf(lbuf, sizeof (lbuf), "%s.%d ",
                                    mp->m_name, mp->m_version);
                                (void) pager_output(lbuf);
                        }
                        if (pager_output("\n"))
                                break;
                }
                if (verbose) {
                        /*
                         * XXX could add some formatting smarts here to
                         * display some better
                         */
                        for (md = fp->f_metadata; md != NULL;
                            md = md->md_next) {
                                (void) snprintf(lbuf, sizeof (lbuf),
                                    "      0x%04x, 0x%lx\n",
                                    md->md_type, (long)md->md_size);
                                if ((ret = pager_output(lbuf)))
                                        break;
                        }
                }
                if (ret != 0)
                        break;
        }
        pager_close();
        return (CMD_OK);
}

/*
 * File level interface, functions file_*
 */
int
file_load(char *filename, vm_offset_t dest, struct preloaded_file **result)
{
        static int last_file_format = 0;
        struct preloaded_file *fp;
        int error;
        int i;

        if (preloaded_files == NULL)
                last_file_format = 0;

        error = EFTYPE;
        for (i = last_file_format, fp = NULL;
            file_formats[i] && fp == NULL; i++) {
                error = (file_formats[i]->l_load)(filename, dest, &fp);
                if (error == 0) {
                        /* remember the loader */
                        fp->f_loader = last_file_format = i;
                        *result = fp;
                        break;
                } else if (last_file_format == i && i != 0) {
                        /* Restart from the beginning */
                        i = -1;
                        last_file_format = 0;
                        fp = NULL;
                        continue;
                }
                if (error == EFTYPE)
                        continue;       /* Unknown to this handler? */
                if (error) {
                        (void) snprintf(command_errbuf, sizeof (command_errbuf),
                            "can't load file '%s': %s", filename,
                            strerror(error));
                        break;
                }
        }
        return (error);
}

static int
file_load_dependencies(struct preloaded_file *base_file)
{
        struct file_metadata *md;
        struct preloaded_file *fp;
        struct mod_depend *verinfo;
        struct kernel_module *mp;
        char *dmodname;
        int error;

        md = file_findmetadata(base_file, MODINFOMD_DEPLIST);
        if (md == NULL)
                return (0);
        error = 0;
        do {
                verinfo = (struct mod_depend *)md->md_data;
                dmodname = (char *)(verinfo + 1);
                if (file_findmodule(NULL, dmodname, verinfo) == NULL) {
                        printf("loading required module '%s'\n", dmodname);
                        error = mod_load(dmodname, verinfo, 0, NULL);
                        if (error)
                                break;
                        /*
                         * If module loaded via kld name which isn't listed
                         * in the linker.hints file, we should check if it have
                         * required version.
                         */
                        mp = file_findmodule(NULL, dmodname, verinfo);
                        if (mp == NULL) {
                                (void) snprintf(command_errbuf,
                                    sizeof (command_errbuf),
                                    "module '%s' exists but with wrong version",
                                    dmodname);
                                error = ENOENT;
                                break;
                        }
                }
                md = metadata_next(md, MODINFOMD_DEPLIST);
        } while (md);
        if (!error)
                return (0);
        /* Load failed; discard everything */
        while (base_file != NULL) {
                fp = base_file;
                base_file = base_file->f_next;
                file_discard(fp);
        }
        return (error);
}

/*
 * Calculate the size of the environment module.
 * The environment is list of name=value C strings, ending with a '\0' byte.
 */
static size_t
env_get_size(void)
{
        size_t size = 0;
        struct env_var *ep;

        /* Traverse the environment. */
        for (ep = environ; ep != NULL; ep = ep->ev_next) {
                size += strlen(ep->ev_name);
                size++;         /* "=" */
                if (ep->ev_value != NULL)
                        size += strlen(ep->ev_value);
                size++;         /* nul byte */
        }
        size++;                 /* nul byte */
        return (size);
}

static void
module_hash(struct preloaded_file *fp, void *addr, size_t size)
{
        uint8_t hash[SHA1_DIGEST_LENGTH];
        char ascii[2 * SHA1_DIGEST_LENGTH + 1];
        int i;

        sha1(addr, size, hash);
        for (i = 0; i < SHA1_DIGEST_LENGTH; i++) {
                (void) snprintf(ascii + 2 * i, sizeof (ascii) - 2 * i, "%02x",
                    hash[i] & 0xff);
        }
        /* Out of memory here is not fatal issue. */
        (void) asprintf(&fp->f_args, "hash=%s", ascii);
}

/*
 * Create virtual module for environment variables.
 * This module should be created as late as possible before executing
 * the OS kernel, or we may miss some environment variable updates.
 */
void
build_environment_module(void)
{
        struct preloaded_file *fp;
        size_t size;
        char *name = "environment";
        vm_offset_t laddr;

        /* We can't load first */
        if (file_findfile(NULL, NULL) == NULL) {
                printf("Can not load environment module: %s\n",
                    "the kernel is not loaded");
                return;
        }

        if (file_findfile(name, name) != NULL) {
                printf("warning: '%s' is already loaded\n", name);
                return;
        }

        tem_save_state();       /* Ask tem to save it's state in env. */
        size = env_get_size();

        fp = file_alloc();
        if (fp != NULL) {
                fp->f_name = strdup(name);
                fp->f_type = strdup(name);
        }

        if (fp == NULL || fp->f_name == NULL || fp->f_type == NULL) {
                printf("Can not load environment module: %s\n",
                    "out of memory");
                file_discard(fp);
                return;
        }


        if (archsw.arch_loadaddr != NULL)
                loadaddr = archsw.arch_loadaddr(LOAD_MEM, &size, loadaddr);

        if (loadaddr == 0) {
                printf("Can not load environment module: %s\n",
                    "out of memory");
                file_discard(fp);
                return;
        }

        laddr = bi_copyenv(loadaddr);
        /* Looks OK so far; populate control structure */
        module_hash(fp, PTOV(loadaddr), laddr - loadaddr);
        fp->f_loader = -1;
        fp->f_addr = loadaddr;
        fp->f_size = laddr - loadaddr;

        /* recognise space consumption */
        loadaddr = laddr;

        file_insert_tail(fp);
}

void
build_font_module(void)
{
        bitmap_data_t *bd;
        struct font *fd;
        struct preloaded_file *fp;
        size_t size;
        uint32_t checksum;
        int i;
        char *name = "console-font";
        vm_offset_t laddr;
        struct font_info fi;
        struct fontlist *fl;

        if (STAILQ_EMPTY(&fonts))
                return;

        /* We can't load first */
        if (file_findfile(NULL, NULL) == NULL) {
                printf("Can not load font module: %s\n",
                    "the kernel is not loaded");
                return;
        }

        if (file_findfile(name, name) != NULL) {
                printf("warning: '%s' is already loaded\n", name);
                return;
        }

        /* helper pointers */
        bd = NULL;
        STAILQ_FOREACH(fl, &fonts, font_next) {
                if (tems.ts_font.vf_width == fl->font_data->width &&
                    tems.ts_font.vf_height == fl->font_data->height) {
                        /*
                         * Kernel does have better built in font.
                         */
                        if (fl->font_flags == FONT_BUILTIN)
                                return;

                        bd = fl->font_data;
                        break;
                }
        }
        if (bd == NULL)
                return;
        fd = bd->font;

        fi.fi_width = fd->vf_width;
        checksum = fi.fi_width;
        fi.fi_height = fd->vf_height;
        checksum += fi.fi_height;
        fi.fi_bitmap_size = bd->uncompressed_size;
        checksum += fi.fi_bitmap_size;

        size = roundup2(sizeof (struct font_info), 8);
        for (i = 0; i < VFNT_MAPS; i++) {
                fi.fi_map_count[i] = fd->vf_map_count[i];
                checksum += fi.fi_map_count[i];
                size += fd->vf_map_count[i] * sizeof (struct font_map);
                size += roundup2(size, 8);
        }
        size += bd->uncompressed_size;

        fi.fi_checksum = -checksum;

        fp = file_alloc();
        if (fp != NULL) {
                fp->f_name = strdup(name);
                fp->f_type = strdup(name);
        }

        if (fp == NULL || fp->f_name == NULL || fp->f_type == NULL) {
                printf("Can not load font module: %s\n",
                    "out of memory");
                file_discard(fp);
                return;
        }

        if (archsw.arch_loadaddr != NULL)
                loadaddr = archsw.arch_loadaddr(LOAD_MEM, &size, loadaddr);

        if (loadaddr == 0) {
                printf("Can not load font module: %s\n",
                    "out of memory");
                file_discard(fp);
                return;
        }

        laddr = loadaddr;
        laddr += archsw.arch_copyin(&fi, laddr, sizeof (struct font_info));
        laddr = roundup2(laddr, 8);

        /* Copy maps. */
        for (i = 0; i < VFNT_MAPS; i++) {
                if (fd->vf_map_count[i] != 0) {
                        laddr += archsw.arch_copyin(fd->vf_map[i], laddr,
                            fd->vf_map_count[i] * sizeof (struct font_map));
                        laddr = roundup2(laddr, 8);
                }
        }

        /* Copy the bitmap. */
        laddr += archsw.arch_copyin(fd->vf_bytes, laddr, fi.fi_bitmap_size);

        /* Looks OK so far; populate control structure */
        module_hash(fp, PTOV(loadaddr), laddr - loadaddr);
        fp->f_loader = -1;
        fp->f_addr = loadaddr;
        fp->f_size = laddr - loadaddr;

        /* recognise space consumption */
        loadaddr = laddr;

        file_insert_tail(fp);
}

/*
 * We've been asked to load (fname) as (type), so just suck it in,
 * no arguments or anything.
 */
struct preloaded_file *
file_loadraw(const char *fname, char *type, int argc, char **argv, int insert)
{
        struct preloaded_file *fp;
        char *name;
        int fd;
        ssize_t got;
        struct stat st;

        /* We can't load first */
        if ((file_findfile(NULL, NULL)) == NULL) {
                command_errmsg = "can't load file before kernel";
                return (NULL);
        }

        /* locate the file on the load path */
        name = file_search(fname, NULL);
        if (name == NULL) {
                (void) snprintf(command_errbuf, sizeof (command_errbuf),
                    "can't find '%s'", fname);
                return (NULL);
        }

        if ((fd = open(name, O_RDONLY)) < 0) {
                (void) snprintf(command_errbuf, sizeof (command_errbuf),
                    "can't open '%s': %s", name, strerror(errno));
                free(name);
                return (NULL);
        }
        if (fstat(fd, &st) < 0) {
                (void) close(fd);
                (void) snprintf(command_errbuf, sizeof (command_errbuf),
                    "stat error '%s': %s", name, strerror(errno));
                free(name);
                return (NULL);
        }

        if (archsw.arch_loadaddr != NULL)
                loadaddr = archsw.arch_loadaddr(LOAD_RAW, name, loadaddr);
        if (loadaddr == 0) {
                (void) close(fd);
                (void) snprintf(command_errbuf, sizeof (command_errbuf),
                    "no memory to load %s", name);
                free(name);
                return (NULL);
        }

        got = archsw.arch_readin(fd, loadaddr, st.st_size);
        if ((size_t)got != st.st_size) {
                (void) snprintf(command_errbuf, sizeof (command_errbuf),
                    "error reading '%s': %s", name, strerror(errno));
                free(name);
                (void) close(fd);
                if (archsw.arch_free_loadaddr != NULL && st.st_size != 0) {
                        archsw.arch_free_loadaddr(loadaddr,
                            (uint64_t)(roundup2(st.st_size, PAGE_SIZE) >> 12));
                }
                return (NULL);
        }

        /* Looks OK so far; create & populate control structure */
        fp = file_alloc();
        if (fp == NULL) {
                if (archsw.arch_free_loadaddr != NULL && st.st_size != 0)
                        archsw.arch_free_loadaddr(loadaddr,
                            (uint64_t)(roundup2(st.st_size, PAGE_SIZE) >> 12));
                (void) snprintf(command_errbuf, sizeof (command_errbuf),
                    "no memory to load %s", name);
                free(name);
                (void) close(fd);
                return (NULL);
        }

        fp->f_name = name;
        fp->f_args = unargv(argc, argv);
        fp->f_type = strdup(type);
        fp->f_metadata = NULL;
        fp->f_loader = -1;
        fp->f_addr = loadaddr;
        fp->f_size = st.st_size;

        if (fp->f_type == NULL ||
            (argc != 0 && fp->f_args == NULL)) {
                (void) close(fd);
                (void) snprintf(command_errbuf, sizeof (command_errbuf),
                    "no memory to load %s", name);
                file_discard(fp);
                return (NULL);
        }
        /* recognise space consumption */
        loadaddr += st.st_size;

        /* Add to the list of loaded files */
        if (insert != 0)
                file_insert_tail(fp);
        (void) close(fd);
        return (fp);
}

/*
 * Load the module (name), pass it (argc),(argv), add container file
 * to the list of loaded files.
 * If module is already loaded just assign new argc/argv.
 */
int
mod_load(char *modname, struct mod_depend *verinfo, int argc, char *argv[])
{
        struct kernel_module *mp;
        int err;
        char *filename;

        if (file_havepath(modname)) {
                printf("Warning: mod_load() called instead of mod_loadkld() "
                    "for module '%s'\n", modname);
                return (mod_loadkld(modname, argc, argv));
        }
        /* see if module is already loaded */
        mp = file_findmodule(NULL, modname, verinfo);
        if (mp != NULL) {
                free(mp->m_args);
                mp->m_args = unargv(argc, argv);
                (void) snprintf(command_errbuf, sizeof (command_errbuf),
                    "warning: module '%s' already loaded", mp->m_name);
                return (0);
        }
        /* locate file with the module on the search path */
        filename = mod_searchmodule(modname, verinfo);
        if (filename == NULL) {
                (void) snprintf(command_errbuf, sizeof (command_errbuf),
                    "can't find '%s'", modname);
                return (ENOENT);
        }
        err = mod_loadkld(filename, argc, argv);
        free(filename);
        return (err);
}

/*
 * Load specified KLD. If path is omitted, then try to locate it via
 * search path.
 */
int
mod_loadkld(const char *kldname, int argc, char *argv[])
{
        struct preloaded_file *fp;
        int err;
        char *filename;
        vm_offset_t loadaddr_saved;

        /*
         * Get fully qualified KLD name
         */
        filename = file_search(kldname, kld_ext_list);
        if (filename == NULL) {
                (void) snprintf(command_errbuf, sizeof (command_errbuf),
                    "can't find '%s'", kldname);
                return (ENOENT);
        }
        /*
         * Check if KLD already loaded
         */
        fp = file_findfile(filename, NULL);
        if (fp != NULL) {
                (void) snprintf(command_errbuf, sizeof (command_errbuf),
                    "warning: KLD '%s' already loaded", filename);
                free(filename);
                return (0);
        }

        do {
                err = file_load(filename, loadaddr, &fp);
                if (err)
                        break;
                fp->f_args = unargv(argc, argv);
                loadaddr_saved = loadaddr;
                loadaddr = fp->f_addr + fp->f_size;
                file_insert_tail(fp);   /* Add to the list of loaded files */
                if (file_load_dependencies(fp) != 0) {
                        err = ENOENT;
                        file_remove(fp);
                        loadaddr = loadaddr_saved;
                        fp = NULL;
                        break;
                }
        } while (0);
        if (err == EFTYPE) {
                (void) snprintf(command_errbuf, sizeof (command_errbuf),
                    "don't know how to load module '%s'", filename);
        }
        if (err)
                file_discard(fp);
        free(filename);
        return (err);
}

/*
 * Find a file matching (name) and (type).
 * NULL may be passed as a wildcard to either.
 */
struct preloaded_file *
file_findfile(const char *name, const char *type)
{
        struct preloaded_file *fp;

        for (fp = preloaded_files; fp != NULL; fp = fp->f_next) {
                if (((name == NULL) || strcmp(name, fp->f_name) == 0) &&
                    ((type == NULL) || strcmp(type, fp->f_type) == 0))
                        break;
        }
        return (fp);
}

/*
 * Find a module matching (name) inside of given file.
 * NULL may be passed as a wildcard.
 */
struct kernel_module *
file_findmodule(struct preloaded_file *fp, char *modname,
    struct mod_depend *verinfo)
{
        struct kernel_module *mp, *best;
        int bestver, mver;

        if (fp == NULL) {
                for (fp = preloaded_files; fp; fp = fp->f_next) {
                        mp = file_findmodule(fp, modname, verinfo);
                        if (mp != NULL)
                                return (mp);
                }
                return (NULL);
        }
        best = NULL;
        bestver = 0;
        for (mp = fp->f_modules; mp; mp = mp->m_next) {
                if (strcmp(modname, mp->m_name) == 0) {
                        if (verinfo == NULL)
                                return (mp);
                        mver = mp->m_version;
                        if (mver == verinfo->md_ver_preferred)
                                return (mp);
                        if (mver >= verinfo->md_ver_minimum &&
                            mver <= verinfo->md_ver_maximum &&
                            mver > bestver) {
                                best = mp;
                                bestver = mver;
                        }
                }
        }
        return (best);
}
/*
 * Make a copy of (size) bytes of data from (p), and associate them as
 * metadata of (type) to the module (mp).
 */
void
file_addmetadata(struct preloaded_file *fp, int type, size_t size, void *p)
{
        struct file_metadata    *md;

        md = malloc(sizeof (struct file_metadata) - sizeof (md->md_data) +
            size);
        if (md != NULL) {
                md->md_size = size;
                md->md_type = type;
                bcopy(p, md->md_data, size);
                md->md_next = fp->f_metadata;
        }
        fp->f_metadata = md;
}

/*
 * Find a metadata object of (type) associated with the file (fp)
 */
struct file_metadata *
file_findmetadata(struct preloaded_file *fp, int type)
{
        struct file_metadata *md;

        for (md = fp->f_metadata; md != NULL; md = md->md_next)
                if (md->md_type == type)
                        break;
        return (md);
}

struct file_metadata *
metadata_next(struct file_metadata *md, int type)
{

        if (md == NULL)
                return (NULL);
        while ((md = md->md_next) != NULL)
                if (md->md_type == type)
                        break;
        return (md);
}

static const char *emptyextlist[] = { "", NULL };

/*
 * Check if the given file is in place and return full path to it.
 */
static char *
file_lookup(const char *path, const char *name, int namelen,
    const char **extlist)
{
        struct stat st;
        char *result, *cp;
        const char **cpp;
        int pathlen, extlen, len;

        pathlen = strlen(path);
        extlen = 0;
        if (extlist == NULL)
                extlist = emptyextlist;
        for (cpp = extlist; *cpp; cpp++) {
                len = strlen(*cpp);
                if (len > extlen)
                        extlen = len;
        }
        result = malloc(pathlen + namelen + extlen + 2);
        if (result == NULL)
                return (NULL);
        bcopy(path, result, pathlen);
        if (pathlen > 0 && result[pathlen - 1] != '/')
                result[pathlen++] = '/';
        cp = result + pathlen;
        bcopy(name, cp, namelen);
        cp += namelen;
        for (cpp = extlist; *cpp; cpp++) {
                (void) strcpy(cp, *cpp);
                if (stat(result, &st) == 0 && S_ISREG(st.st_mode))
                        return (result);
        }
        free(result);
        return (NULL);
}

/*
 * Check if file name have any qualifiers
 */
static int
file_havepath(const char *name)
{
        const char *cp;

        (void) archsw.arch_getdev(NULL, name, &cp);
        return (cp != name || strchr(name, '/') != NULL);
}

/*
 * Attempt to find the file (name) on the module searchpath.
 * If (name) is qualified in any way, we simply check it and
 * return it or NULL.  If it is not qualified, then we attempt
 * to construct a path using entries in the environment variable
 * module_path.
 *
 * The path we return a pointer to need never be freed, as we manage
 * it internally.
 */
static char *
file_search(const char *name, const char **extlist)
{
        struct moduledir *mdp;
        struct stat sb;
        char *result;
        int namelen;

        /* Don't look for nothing */
        if (name == NULL)
                return (NULL);

        if (*name == '\0')
                return (strdup(name));

        if (file_havepath(name)) {
                /* Qualified, so just see if it exists */
                if (stat(name, &sb) == 0)
                        return (strdup(name));
                return (NULL);
        }
        moduledir_rebuild();
        result = NULL;
        namelen = strlen(name);
        STAILQ_FOREACH(mdp, &moduledir_list, d_link) {
                result = file_lookup(mdp->d_path, name, namelen, extlist);
                if (result != NULL)
                        break;
        }
        return (result);
}

#define INT_ALIGN(base, ptr)    ptr = \
        (base) + (((ptr) - (base) + sizeof (int) - 1) & ~(sizeof (int) - 1))

static char *
mod_search_hints(struct moduledir *mdp, const char *modname,
    struct mod_depend *verinfo)
{
        uchar_t *cp, *recptr, *bufend, *best;
        char *result;
        int *intp, bestver, blen, clen, ival, modnamelen, reclen;
        bool found;

        moduledir_readhints(mdp);
        modnamelen = strlen(modname);
        found = false;
        result = NULL;
        bestver = 0;
        if (mdp->d_hints == NULL)
                goto bad;
        recptr = mdp->d_hints;
        bufend = recptr + mdp->d_hintsz;
        clen = blen = 0;
        best = cp = NULL;
        while (recptr < bufend && !found) {
                intp = (int *)recptr;
                reclen = *intp++;
                ival = *intp++;
                cp = (uchar_t *)intp;
                switch (ival) {
                case MDT_VERSION:
                        clen = *cp++;
                        if (clen != modnamelen || bcmp(cp, modname, clen) != 0)
                                break;
                        cp += clen;
                        INT_ALIGN(mdp->d_hints, cp);
                        ival = *(int *)cp;
                        cp += sizeof (int);
                        clen = *cp++;
                        if (verinfo == NULL ||
                            ival == verinfo->md_ver_preferred) {
                                found = true;
                                break;
                        }
                        if (ival >= verinfo->md_ver_minimum &&
                            ival <= verinfo->md_ver_maximum &&
                            ival > bestver) {
                                bestver = ival;
                                best = cp;
                                blen = clen;
                        }
                        break;
                default:
                        break;
                }
                recptr += reclen + sizeof (int);
        }
        /*
         * Finally check if KLD is in the place
         */
        if (found)
                result = file_lookup(mdp->d_path, (char *)cp, clen, NULL);
        else if (best)
                result = file_lookup(mdp->d_path, (char *)best, blen, NULL);
bad:
        /*
         * If nothing found or hints is absent - fallback to the old way
         * by using "kldname[.ko]" as module name.
         */
        if (!found && bestver == 0 && result == NULL) {
                result = file_lookup(mdp->d_path, modname, modnamelen,
                    kld_ext_list);
        }
        return (result);
}

/*
 * Attempt to locate the file containing the module (name)
 */
static char *
mod_searchmodule(char *name, struct mod_depend *verinfo)
{
        struct moduledir *mdp;
        char *result;

        moduledir_rebuild();
        /*
         * Now we ready to lookup module in the given directories
         */
        result = NULL;
        STAILQ_FOREACH(mdp, &moduledir_list, d_link) {
                result = mod_search_hints(mdp, name, verinfo);
                if (result != NULL)
                        break;
        }

        return (result);
}

int
file_addmodule(struct preloaded_file *fp, char *modname, int version,
    struct kernel_module **newmp)
{
        struct kernel_module *mp;
        struct mod_depend mdepend;

        bzero(&mdepend, sizeof (mdepend));
        mdepend.md_ver_preferred = version;
        mp = file_findmodule(fp, modname, &mdepend);
        if (mp != NULL)
                return (EEXIST);
        mp = calloc(1, sizeof (struct kernel_module));
        if (mp == NULL)
                return (ENOMEM);
        mp->m_name = strdup(modname);
        if (mp->m_name == NULL) {
                free(mp);
                return (ENOMEM);
        }
        mp->m_version = version;
        mp->m_fp = fp;
        mp->m_next = fp->f_modules;
        fp->f_modules = mp;
        if (newmp)
                *newmp = mp;
        return (0);
}

/*
 * Throw a file away
 */
void
file_discard(struct preloaded_file *fp)
{
        struct file_metadata *md, *md1;
        struct kernel_module *mp, *mp1;

        if (fp == NULL)
                return;

        if (archsw.arch_free_loadaddr != NULL && fp->f_addr &&
            fp->f_size != 0) {
                archsw.arch_free_loadaddr(fp->f_addr,
                    (uint64_t)(roundup2(fp->f_size, PAGE_SIZE) >> 12));
        }

        md = fp->f_metadata;
        while (md != NULL) {
                md1 = md;
                md = md->md_next;
                free(md1);
        }
        mp = fp->f_modules;
        while (mp != NULL) {
                free(mp->m_name);
                mp1 = mp;
                mp = mp->m_next;
                free(mp1);
        }
        free(fp->f_name);
        free(fp->f_type);
        free(fp->f_args);
        free(fp);
}

/*
 * Allocate a new file; must be used instead of malloc()
 * to ensure safe initialisation.
 */
struct preloaded_file *
file_alloc(void)
{

        return (calloc(1, sizeof (struct preloaded_file)));
}

/*
 * Add a module to the chain
 */
static void
file_insert_tail(struct preloaded_file *fp)
{
        struct preloaded_file *cm;

        /* Append to list of loaded file */
        fp->f_next = NULL;
        if (preloaded_files == NULL) {
                preloaded_files = fp;
        } else {
                for (cm = preloaded_files; cm->f_next != NULL; cm = cm->f_next)
                        ;
                cm->f_next = fp;
        }
}

/*
 * Remove module from the chain
 */
static void
file_remove(struct preloaded_file *fp)
{
        struct preloaded_file   *cm;

        if (preloaded_files == NULL)
                return;

        if (preloaded_files == fp) {
                preloaded_files = fp->f_next;
                return;
        }
        for (cm = preloaded_files; cm->f_next != NULL; cm = cm->f_next) {
                if (cm->f_next == fp) {
                        cm->f_next = fp->f_next;
                        return;
                }
        }
}

static char *
moduledir_fullpath(struct moduledir *mdp, const char *fname)
{
        char *cp;

        cp = malloc(strlen(mdp->d_path) + strlen(fname) + 2);
        if (cp == NULL)
                return (NULL);
        strcpy(cp, mdp->d_path);
        strcat(cp, "/");
        strcat(cp, fname);
        return (cp);
}

/*
 * Read linker.hints file into memory performing some sanity checks.
 */
static void
moduledir_readhints(struct moduledir *mdp)
{
        struct stat st;
        char *path;
        int fd, size, version;

        if (mdp->d_hints != NULL || (mdp->d_flags & MDIR_NOHINTS))
                return;
        path = moduledir_fullpath(mdp, "linker.hints");
        if (stat(path, &st) != 0 ||
            st.st_size < (ssize_t)(sizeof (version) + sizeof (int)) ||
            st.st_size > LINKER_HINTS_MAX ||
            (fd = open(path, O_RDONLY)) < 0) {
                free(path);
                mdp->d_flags |= MDIR_NOHINTS;
                return;
        }
        free(path);
        size = read(fd, &version, sizeof (version));
        if (size != sizeof (version) || version != LINKER_HINTS_VERSION)
                goto bad;
        size = st.st_size - size;
        mdp->d_hints = malloc(size);
        if (mdp->d_hints == NULL)
                goto bad;
        if (read(fd, mdp->d_hints, size) != size)
                goto bad;
        mdp->d_hintsz = size;
        (void) close(fd);
        return;
bad:
        (void) close(fd);
        free(mdp->d_hints);
        mdp->d_hints = NULL;
        mdp->d_flags |= MDIR_NOHINTS;
}

/*
 * Extract directories from the ';' separated list, remove duplicates.
 */
static void
moduledir_rebuild(void)
{
        struct moduledir *mdp, *mtmp;
        const char *path, *cp, *ep;
        size_t cplen;

        path = getenv("module_path");
        if (path == NULL)
                path = default_searchpath;
        /*
         * Rebuild list of module directories if it changed
         */
        STAILQ_FOREACH(mdp, &moduledir_list, d_link)
                mdp->d_flags |= MDIR_REMOVED;

        for (ep = path; *ep != 0; ep++) {
                cp = ep;
                for (; *ep != 0 && *ep != ';'; ep++)
                        ;
                /*
                 * Ignore trailing slashes
                 */
                for (cplen = ep - cp; cplen > 1 && cp[cplen - 1] == '/';
                    cplen--)
                        ;
                STAILQ_FOREACH(mdp, &moduledir_list, d_link) {
                        if (strlen(mdp->d_path) != cplen ||
                            bcmp(cp, mdp->d_path, cplen) != 0)
                                continue;
                        mdp->d_flags &= ~MDIR_REMOVED;
                        break;
                }
                if (mdp == NULL) {
                        mdp = malloc(sizeof (*mdp) + cplen + 1);
                        if (mdp == NULL)
                                return;
                        mdp->d_path = (char *)(mdp + 1);
                        bcopy(cp, mdp->d_path, cplen);
                        mdp->d_path[cplen] = 0;
                        mdp->d_hints = NULL;
                        mdp->d_flags = 0;
                        STAILQ_INSERT_TAIL(&moduledir_list, mdp, d_link);
                }
                if (*ep == '\0')
                        break;
        }
        /*
         * Delete unused directories if any
         */
        mdp = STAILQ_FIRST(&moduledir_list);
        while (mdp) {
                if ((mdp->d_flags & MDIR_REMOVED) == 0) {
                        mdp = STAILQ_NEXT(mdp, d_link);
                } else {
                        free(mdp->d_hints);
                        mtmp = mdp;
                        mdp = STAILQ_NEXT(mdp, d_link);
                        STAILQ_REMOVE(&moduledir_list, mtmp, moduledir, d_link);
                        free(mtmp);
                }
        }
}