/*
 * 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 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 * Copyright (c) 2016 by Delphix. All rights reserved.
 * Copyright 2022 Oxide Computer Company
 * Copyright 2025 MNX Cloud, Inc.
 */

#include <sys/types.h>
#include <sys/param.h>
#include <sys/vnode.h>
#include <sys/fs/ufs_fsdir.h>
#include <sys/fs/ufs_fs.h>
#include <sys/fs/ufs_inode.h>
#include <sys/sysmacros.h>
#include <sys/bootvfs.h>
#include <sys/filep.h>
#include <sys/kmem.h>
#include <sys/kobj.h>
#include <sys/sunddi.h>

extern void *bkmem_alloc(size_t);
extern void bkmem_free(void *, size_t);
extern int cf_check_compressed(fileid_t *);
extern void cf_close(fileid_t *);
extern void cf_seek(fileid_t *, off_t, int);
extern int cf_read(fileid_t *, caddr_t, size_t);

extern int bootrd_debug;

/*
 * This fd is used when talking to the device file itself.
 */
static fileid_t *head;

/* Only got one of these...ergo, only 1 fs open at once */
/* static */
devid_t         *ufs_devp;

struct dirinfo {
        int     loc;
        fileid_t *fi;
};

static  int     bufs_close(int);
static  void    bufs_closeall(int);
static  ino_t   find(fileid_t *filep, char *path);
static  ino_t   dlook(fileid_t *filep, char *path);
static  daddr32_t       sbmap(fileid_t *filep, daddr32_t bn);
static  struct direct *readdir(struct dirinfo *dstuff);
static  void set_cache(int, void *, uint_t);
static  void *get_cache(int);
static  void free_cache();


/*
 *      There is only 1 open (mounted) device at any given time.
 *      So we can keep a single, global devp file descriptor to
 *      use to index into the di[] array.  This is not true for the
 *      fi[] array.  We can have more than one file open at once,
 *      so there is no global fd for the fi[].
 *      The user program must save the fd passed back from open()
 *      and use it to do subsequent read()'s.
 */

static int
openi(fileid_t *filep, ino_t inode)
{
        struct dinode *dp;
        devid_t *devp = filep->fi_devp;

        filep->fi_inode = get_cache((int)inode);
        if (filep->fi_inode != 0)
                return (0);

        filep->fi_offset = 0;
        filep->fi_blocknum = fsbtodb(&devp->un_fs.di_fs,
            itod(&devp->un_fs.di_fs, inode));

        /* never more than 1 disk block */
        filep->fi_count = devp->un_fs.di_fs.fs_bsize;
        filep->fi_memp = 0;             /* cached read */
        if (diskread(filep) != 0) {
                return (0);
        }

        dp = (struct dinode *)filep->fi_memp;
        filep->fi_inode = (struct inode *)
            bkmem_alloc(sizeof (struct inode));
        bzero((char *)filep->fi_inode, sizeof (struct inode));
        filep->fi_inode->i_ic =
            dp[itoo(&devp->un_fs.di_fs, inode)].di_un.di_icom;
        filep->fi_inode->i_number = inode;
        set_cache((int)inode, (void *)filep->fi_inode, sizeof (struct inode));
        return (0);
}

static fileid_t *
find_fp(int fd)
{
        fileid_t *filep = head;

        if (fd >= 0) {
                while ((filep = filep->fi_forw) != head)
                        if (fd == filep->fi_filedes)
                                return (filep->fi_taken ? filep : 0);
        }

        return (0);
}

static ino_t
find(fileid_t *filep, char *path)
{
        char *q;
        char c;
        ino_t inode;
        char lpath[MAXPATHLEN];
        char *lpathp = lpath;
        int len, r;
        devid_t *devp;

        inode = 0;
        if (path == NULL || *path == '\0') {
                kobj_printf("null path\n");
                return (inode);
        }

        if (bootrd_debug)
                kobj_printf("openi: %s\n", path);

        bzero(lpath, sizeof (lpath));
        bcopy(path, lpath, strlen(path));
        devp = filep->fi_devp;
        while (*lpathp) {
                /* if at the beginning of pathname get root inode */
                r = (lpathp == lpath);
                if (r && openi(filep, (ino_t)UFSROOTINO))
                        return ((ino_t)0);
                while (*lpathp == '/')
                        lpathp++;       /* skip leading slashes */
                q = lpathp;
                while (*q != '/' && *q != '\0')
                        q++;            /* find end of component */
                c = *q;
                *q = '\0';              /* terminate component */

                /* Bail out early if opening root */
                if (r && (*lpathp == '\0'))
                        return ((ino_t)UFSROOTINO);
                if ((inode = dlook(filep, lpathp)) != 0) {
                        if (openi(filep, inode))
                                return ((ino_t)0);
                        if ((filep->fi_inode->i_smode & IFMT) == IFLNK) {
                                filep->fi_blocknum =
                                    fsbtodb(&devp->un_fs.di_fs,
                                    filep->fi_inode->i_db[0]);
                                filep->fi_count = DEV_BSIZE;
                                filep->fi_memp = 0;
                                if (diskread(filep) != 0)
                                        return ((ino_t)0);
                                len = strlen(filep->fi_memp);
                                if (filep->fi_memp[0] == '/')
                                        /* absolute link */
                                        lpathp = lpath;
                                /* copy rest of unprocessed path up */
                                bcopy(q, lpathp + len, strlen(q + 1) + 2);
                                /* point to unprocessed path */
                                *(lpathp + len) = c;
                                /* prepend link in before unprocessed path */
                                bcopy(filep->fi_memp, lpathp, len);
                                lpathp = lpath;
                                continue;
                        } else
                                *q = c;
                        if (c == '\0')
                                break;
                        lpathp = q;
                        continue;
                } else {
                        return ((ino_t)0);
                }
        }
        return (inode);
}

static daddr32_t
sbmap(fileid_t *filep, daddr32_t bn)
{
        struct inode *inodep;
        int i, j, sh;
        daddr32_t nb, *bap;
        daddr32_t *db;
        devid_t *devp;

        devp = filep->fi_devp;
        inodep = filep->fi_inode;
        db = inodep->i_db;

        /*
         * blocks 0..NDADDR are direct blocks
         */
        if (bn < NDADDR) {
                nb = db[bn];
                return (nb);
        }

        /*
         * addresses NIADDR have single and double indirect blocks.
         * the first step is to determine how many levels of indirection.
         */
        sh = 1;
        bn -= NDADDR;
        for (j = NIADDR; j > 0; j--) {
                sh *= NINDIR(&devp->un_fs.di_fs);
                if (bn < sh)
                        break;
                bn -= sh;
        }
        if (j == 0) {
                return ((daddr32_t)0);
        }

        /*
         * fetch the first indirect block address from the inode
         */
        nb = inodep->i_ib[NIADDR - j];
        if (nb == 0) {
                return ((daddr32_t)0);
        }

        /*
         * fetch through the indirect blocks
         */
        for (; j <= NIADDR; j++) {
                filep->fi_blocknum = fsbtodb(&devp->un_fs.di_fs, nb);
                filep->fi_count = devp->un_fs.di_fs.fs_bsize;
                filep->fi_memp = 0;
                if (diskread(filep) != 0)
                        return (0);
                bap = (daddr32_t *)filep->fi_memp;
                sh /= NINDIR(&devp->un_fs.di_fs);
                i = (bn / sh) % NINDIR(&devp->un_fs.di_fs);
                nb = bap[i];
                if (nb == 0) {
                        return ((daddr32_t)0);
                }
        }
        return (nb);
}

static ino_t
dlook(fileid_t *filep, char *path)
{
        struct direct *dp;
        struct inode *ip;
        struct dirinfo dirp;
        int len;

        ip = filep->fi_inode;
        if (path == NULL || *path == '\0')
                return (0);

        if (bootrd_debug)
                kobj_printf("dlook: %s\n", path);

        if ((ip->i_smode & IFMT) != IFDIR) {
                return (0);
        }
        if (ip->i_size == 0) {
                return (0);
        }
        len = strlen(path);
        dirp.loc = 0;
        dirp.fi = filep;
        for (dp = readdir(&dirp); dp != NULL; dp = readdir(&dirp)) {
                if (dp->d_ino == 0)
                        continue;
                if (dp->d_namlen == len && strcmp(path, dp->d_name) == 0) {
                        return (dp->d_ino);
                }
                /* Allow "*" to print all names at that level, w/out match */
                if (strcmp(path, "*") == 0 && bootrd_debug)
                        kobj_printf("%s\n", dp->d_name);
        }
        return (0);
}

/*
 * get next entry in a directory.
 */
struct direct *
readdir(struct dirinfo *dstuff)
{
        struct direct *dp;
        fileid_t *filep;
        daddr32_t lbn, d;
        int off;
        devid_t *devp;

        filep = dstuff->fi;
        devp = filep->fi_devp;
        for (;;) {
                if (dstuff->loc >= filep->fi_inode->i_size) {
                        return (NULL);
                }
                off = blkoff(&devp->un_fs.di_fs, dstuff->loc);
                if (bootrd_debug)
                        kobj_printf("readdir: off = 0x%x\n", off);
                if (off == 0) {
                        lbn = lblkno(&devp->un_fs.di_fs, dstuff->loc);
                        d = sbmap(filep, lbn);

                        if (d == 0)
                                return (NULL);

                        filep->fi_blocknum = fsbtodb(&devp->un_fs.di_fs, d);
                        filep->fi_count =
                            blksize(&devp->un_fs.di_fs, filep->fi_inode, lbn);
                        filep->fi_memp = 0;
                        if (diskread(filep) != 0) {
                                return (NULL);
                        }
                }
                dp = (struct direct *)(filep->fi_memp + off);
                dstuff->loc += dp->d_reclen;
                if (dp->d_ino == 0)
                        continue;
                if (bootrd_debug)
                        kobj_printf("readdir: name = %s\n", dp->d_name);
                return (dp);
        }
}

/*
 * Get the next block of data from the file.  If possible, dma right into
 * user's buffer
 */
static int
getblock(fileid_t *filep, caddr_t buf, int count, int *rcount)
{
        struct fs *fs;
        caddr_t p;
        int off, size, diff;
        daddr32_t lbn;
        devid_t *devp;

        if (bootrd_debug)
                kobj_printf("getblock: buf 0x%p, count 0x%x\n",
                    (void *)buf, count);

        devp = filep->fi_devp;
        p = filep->fi_memp;
        if ((signed)filep->fi_count <= 0) {

                /* find the amt left to be read in the file */
                diff = filep->fi_inode->i_size - filep->fi_offset;
                if (diff <= 0) {
                        kobj_printf("Short read\n");
                        return (-1);
                }

                fs = &devp->un_fs.di_fs;
                /* which block (or frag) in the file do we read? */
                lbn = lblkno(fs, filep->fi_offset);

                /* which physical block on the device do we read? */
                filep->fi_blocknum = fsbtodb(fs, sbmap(filep, lbn));

                off = blkoff(fs, filep->fi_offset);

                /* either blksize or fragsize */
                size = blksize(fs, filep->fi_inode, lbn);
                filep->fi_count = size;
                filep->fi_memp = filep->fi_buf;

                /*
                 * optimization if we are reading large blocks of data then
                 * we can go directly to user's buffer
                 */
                *rcount = 0;
                if (off == 0 && count >= size) {
                        filep->fi_memp = buf;
                        if (diskread(filep)) {
                                return (-1);
                        }
                        *rcount = size;
                        filep->fi_count = 0;
                        return (0);
                } else if (diskread(filep))
                        return (-1);

                if (filep->fi_offset - off + size >= filep->fi_inode->i_size)
                        filep->fi_count = diff + off;
                filep->fi_count -= off;
                p = &filep->fi_memp[off];
        }
        filep->fi_memp = p;
        return (0);
}

/*
 * Get the next block of data from the file.  Don't attempt to go directly
 * to user's buffer.
 */
static int
getblock_noopt(fileid_t *filep)
{
        struct fs *fs;
        caddr_t p;
        int off, size, diff;
        daddr32_t lbn;
        devid_t *devp;

        if (bootrd_debug)
                kobj_printf("getblock_noopt: start\n");

        devp = filep->fi_devp;
        p = filep->fi_memp;
        if ((signed)filep->fi_count <= 0) {

                /* find the amt left to be read in the file */
                diff = filep->fi_inode->i_size - filep->fi_offset;
                if (diff <= 0) {
                        kobj_printf("Short read\n");
                        return (-1);
                }

                fs = &devp->un_fs.di_fs;
                /* which block (or frag) in the file do we read? */
                lbn = lblkno(fs, filep->fi_offset);

                /* which physical block on the device do we read? */
                filep->fi_blocknum = fsbtodb(fs, sbmap(filep, lbn));

                off = blkoff(fs, filep->fi_offset);

                /* either blksize or fragsize */
                size = blksize(fs, filep->fi_inode, lbn);
                filep->fi_count = size;
                /* reading on a ramdisk, just get a pointer to the data */
                filep->fi_memp = NULL;

                if (diskread(filep))
                        return (-1);

                if (filep->fi_offset - off + size >= filep->fi_inode->i_size)
                        filep->fi_count = diff + off;
                filep->fi_count -= off;
                p = &filep->fi_memp[off];
        }
        filep->fi_memp = p;
        return (0);
}


/*
 *  This is the high-level read function.  It works like this.
 *  We assume that our IO device buffers up some amount of
 *  data and that we can get a ptr to it.  Thus we need
 *  to actually call the device func about filesize/blocksize times
 *  and this greatly increases our IO speed.  When we already
 *  have data in the buffer, we just return that data (with bcopy() ).
 */

static ssize_t
bufs_read(int fd, caddr_t buf, size_t count)
{
        size_t i, j;
        caddr_t n;
        int rcount;
        fileid_t *filep;

        if (!(filep = find_fp(fd))) {
                return (-1);
        }

        if ((filep->fi_flags & FI_COMPRESSED) == 0 &&
            filep->fi_offset + count > filep->fi_inode->i_size)
                count = filep->fi_inode->i_size - filep->fi_offset;

        /* that was easy */
        if ((i = count) == 0)
                return (0);

        n = buf;
        while (i > 0) {
                if (filep->fi_flags & FI_COMPRESSED) {
                        int rval;

                        if ((rval = cf_read(filep, buf, count)) < 0)
                                return (0); /* encountered an error */
                        j = (size_t)rval;
                        if (j < i)
                                i = j; /* short read, must have hit EOF */
                } else {
                        /* If we need to reload the buffer, do so */
                        if ((j = filep->fi_count) == 0) {
                                (void) getblock(filep, buf, i, &rcount);
                                i -= rcount;
                                buf += rcount;
                                filep->fi_offset += rcount;
                                continue;
                        } else {
                                /* else just bcopy from our buffer */
                                j = MIN(i, j);
                                bcopy(filep->fi_memp, buf, (unsigned)j);
                        }
                }
                buf += j;
                filep->fi_memp += j;
                filep->fi_offset += j;
                filep->fi_count -= j;
                i -= j;
        }
        return (buf - n);
}

/*
 *      This routine will open a device as it is known by the V2 OBP.
 *      Interface Defn:
 *      err = mountroot(string);
 *              err = 0 on success
 *              err = -1 on failure
 *      string: char string describing the properties of the device.
 *      We must not dork with any fi[]'s here.  Save that for later.
 */

static int
bufs_mountroot(char *str)
{
        if (ufs_devp)           /* already mounted */
                return (0);

        ufs_devp = (devid_t *)bkmem_alloc(sizeof (devid_t));
        ufs_devp->di_taken = 1;
        ufs_devp->di_dcookie = 0;
        ufs_devp->di_desc = (char *)bkmem_alloc(strlen(str) + 1);
        (void) strcpy(ufs_devp->di_desc, str);
        bzero(ufs_devp->un_fs.dummy, SBSIZE);
        head = (fileid_t *)bkmem_alloc(sizeof (fileid_t));
        head->fi_back = head->fi_forw = head;
        head->fi_filedes = 0;
        head->fi_taken = 0;

        /* Setup read of the superblock */
        head->fi_devp = ufs_devp;
        head->fi_blocknum = SBLOCK;
        head->fi_count = (uint_t)SBSIZE;
        head->fi_memp = (caddr_t)&(ufs_devp->un_fs.di_fs);
        head->fi_offset = 0;

        if (diskread(head)) {
                kobj_printf("failed to read superblock\n");
                (void) bufs_closeall(1);
                return (-1);
        }

        if (ufs_devp->un_fs.di_fs.fs_magic != FS_MAGIC) {
                if (bootrd_debug)
                        kobj_printf("fs magic = 0x%x\n",
                            ufs_devp->un_fs.di_fs.fs_magic);
                (void) bufs_closeall(1);
                return (-1);
        }
        if (bootrd_debug)
                kobj_printf("mountroot succeeded\n");
        return (0);
}

/*
 * Unmount the currently mounted root fs.  In practice, this means
 * closing all open files and releasing resources.  All of this
 * is done by closeall().
 */

static int
bufs_unmountroot(void)
{
        if (ufs_devp == NULL)
                return (-1);

        (void) bufs_closeall(1);

        return (0);
}

/*
 *      We allocate an fd here for use when talking
 *      to the file itself.
 */

static int
bufs_open(char *filename, int flags __unused)
{
        fileid_t        *filep;
        ino_t   inode;
        static int      filedes = 1;

        if (bootrd_debug)
                kobj_printf("open: %s\n", filename);

        /* build and link a new file descriptor */
        filep = (fileid_t *)bkmem_alloc(sizeof (fileid_t));
        filep->fi_back = head->fi_back;
        filep->fi_forw = head;
        head->fi_back->fi_forw = filep;
        head->fi_back = filep;
        filep->fi_filedes = filedes++;
        filep->fi_taken = 1;
        filep->fi_path = (char *)bkmem_alloc(strlen(filename) + 1);
        (void) strcpy(filep->fi_path, filename);
        filep->fi_devp = ufs_devp; /* dev is already "mounted" */
        filep->fi_inode = NULL;
        bzero(filep->fi_buf, MAXBSIZE);
        filep->fi_getblock = getblock_noopt;
        filep->fi_flags = 0;

        inode = find(filep, (char *)filename);
        if (inode == 0) {
                if (bootrd_debug)
                        kobj_printf("open: cannot find %s\n", filename);
                (void) bufs_close(filep->fi_filedes);
                return (-1);
        }
        if (openi(filep, inode)) {
                kobj_printf("open: cannot open %s\n", filename);
                (void) bufs_close(filep->fi_filedes);
                return (-1);
        }

        filep->fi_offset = filep->fi_count = 0;

        if (cf_check_compressed(filep) != 0)
                return (-1);
        return (filep->fi_filedes);
}

/*
 *  We don't do any IO here.
 *  We just play games with the device pointers.
 */

static off_t
bufs_lseek(int fd, off_t addr, int whence)
{
        fileid_t *filep;

        /* Make sure user knows what file they are talking to */
        if (!(filep = find_fp(fd)))
                return (-1);

        if (filep->fi_flags & FI_COMPRESSED) {
                cf_seek(filep, addr, whence);
        } else {
                switch (whence) {
                case SEEK_CUR:
                        filep->fi_offset += addr;
                        break;
                case SEEK_SET:
                        filep->fi_offset = addr;
                        break;
                default:
                case SEEK_END:
                        kobj_printf("lseek(): invalid whence value %d\n",
                            whence);
                        break;
                }
                filep->fi_blocknum = addr / DEV_BSIZE;
        }

        filep->fi_count = 0;

        return (0);
}


int
bufs_fstat(int fd, struct bootstat *stp)
{
        fileid_t        *filep;
        struct inode    *ip;

        if (!(filep = find_fp(fd)))
                return (-1);

        ip = filep->fi_inode;

        stp->st_mode = 0;
        stp->st_size = 0;

        if (ip == NULL)
                return (0);

        switch (ip->i_smode & IFMT) {
        case IFLNK:
                stp->st_mode = S_IFLNK;
                break;
        case IFREG:
                stp->st_mode = S_IFREG;
                break;
        default:
                break;
        }
        /*
         * NOTE: this size will be the compressed size for a compressed file
         * This could confuse the caller since we decompress the file behind
         * the scenes when the file is read.
         */
        stp->st_size = ip->i_size;
        stp->st_atim.tv_sec = ip->i_atime.tv_sec;
        stp->st_atim.tv_nsec = ip->i_atime.tv_usec * 1000;
        stp->st_mtim.tv_sec = ip->i_mtime.tv_sec;
        stp->st_mtim.tv_nsec = ip->i_mtime.tv_usec * 1000;
        stp->st_ctim.tv_sec = ip->i_ctime.tv_sec;
        stp->st_ctim.tv_nsec = ip->i_ctime.tv_usec * 1000;

        return (0);
}


static int
bufs_close(int fd)
{
        fileid_t *filep;

        /* Make sure user knows what file they are talking to */
        if (!(filep = find_fp(fd)))
                return (-1);

        if (filep->fi_taken && (filep != head)) {
                /* Clear the ranks */
                bkmem_free(filep->fi_path, strlen(filep->fi_path)+1);
                filep->fi_blocknum = filep->fi_count = filep->fi_offset = 0;
                filep->fi_memp = (caddr_t)0;
                filep->fi_devp = 0;
                filep->fi_taken = 0;

                /* unlink and deallocate node */
                filep->fi_forw->fi_back = filep->fi_back;
                filep->fi_back->fi_forw = filep->fi_forw;
                cf_close(filep);
                bkmem_free((char *)filep, sizeof (fileid_t));

                /*
                 * Some files are opened and closed in early boot, for example
                 * when doing a microcode update on the boot CPU. In that case
                 * the inode cache will contain memory allocated from boot
                 * pages, which will be invalid once kmem is initialised.
                 * Until kmem is ready, clear the inode cache when closing a
                 * file.
                 */
                if (kmem_ready == 0)
                        free_cache();

                return (0);
        } else {
                /* Big problem */
                kobj_printf("\nFile descrip %d not allocated!", fd);
                return (-1);
        }
}

static void
bufs_closeall(int flag __unused)
{
        fileid_t *filep = head;

        while ((filep = filep->fi_forw) != head)
                if (filep->fi_taken)
                        if (bufs_close(filep->fi_filedes))
                                kobj_printf(
                                    "Filesystem may be inconsistent.\n");

        ufs_devp->di_taken = 0;
        bkmem_free((char *)ufs_devp, sizeof (devid_t));
        bkmem_free((char *)head, sizeof (fileid_t));
        ufs_devp = NULL;
        head = NULL;
        free_cache();
}

static struct cache {
        struct cache *next;
        void *data;
        int key;
        uint_t size;
} *icache;

void
set_cache(int key, void *data, uint_t size)
{
        struct cache *entry = bkmem_alloc(sizeof (*entry));
        entry->key = key;
        entry->data = data;
        entry->size = size;
        if (icache) {
                entry->next = icache;
                icache = entry;
        } else {
                icache = entry;
                entry->next = 0;
        }
}

void *
get_cache(int key)
{
        struct cache *entry = icache;
        while (entry) {
                if (entry->key == key)
                        return (entry->data);
                entry = entry->next;
        }
        return (NULL);
}

void
free_cache()
{
        struct cache *next, *entry = icache;
        while (entry) {
                next = entry->next;
                bkmem_free(entry->data, entry->size);
                bkmem_free(entry, sizeof (*entry));
                entry = next;
        }
        icache = 0;
}

struct boot_fs_ops bufs_ops = {
        "boot_ufs",
        bufs_mountroot,
        bufs_unmountroot,
        bufs_open,
        bufs_close,
        bufs_read,
        bufs_lseek,
        bufs_fstat,
        NULL
};