xfs_db: write values into dir/attr blocks and recalculate CRCs

[thirdparty/xfsprogs-dev.git] / db / write.c

/*
 * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it would be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write the Free Software Foundation,
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include "libxfs.h"
#include <ctype.h>
#include <time.h>
#include "bit.h"
#include "block.h"
#include "command.h"
#include "type.h"
#include "faddr.h"
#include "fprint.h"
#include "field.h"
#include "flist.h"
#include "io.h"
#include "init.h"
#include "output.h"
#include "print.h"
#include "write.h"
#include "malloc.h"

static int      write_f(int argc, char **argv);
static void     write_help(void);

static const cmdinfo_t  write_cmd =
        { "write", NULL, write_f, 0, -1, 0, N_("[-c] [field or value]..."),
          N_("write value to disk"), write_help };

void
write_init(void)
{
        if (!expert_mode)
                return;

        add_command(&write_cmd);
        srand48(clock());
}

static void
write_help(void)
{
        dbprintf(_(
"\n"
" The 'write' command takes on different personalities depending on the\n"
" type of object being worked with.\n\n"
" Write has 3 modes:\n"
"  'struct mode' - is active anytime you're looking at a filesystem object\n"
"                  which contains individual fields (ex: an inode).\n"
"  'data mode'   - is active anytime you set a disk address directly or set\n"
"                  the type to 'data'.\n"
"  'string mode' - only used for writing symlink blocks.\n"
"\n"
" Examples:\n"
"  Struct mode: 'write core.uid 23'          - set an inode uid field to 23.\n"
"               'write fname \"hello\\000\"'    - write superblock fname.\n"
"               (note: in struct mode strings are not null terminated)\n"
"               'write fname #6669736800'    - write superblock fname with hex.\n"
"               'write uuid 00112233-4455-6677-8899-aabbccddeeff'\n"
"                                            - write superblock uuid.\n"
"  Data mode:   'write fill 0xff' - fill the entire block with 0xff's\n"
"               'write lshift 3' - shift the block 3 bytes to the left\n"
"               'write sequence 1 5' - write a cycle of number [1-5] through\n"
"                                      the entire block.\n"
"  String mode: 'write \"This_is_a_filename\" - write null terminated string.\n"
"\n"
" In data mode type 'write' by itself for a list of specific commands.\n\n"
" Specifying the -c option will allow writes of invalid (corrupt) data with\n"
" an invalid CRC. Specifying the -d option will allow writes of invalid data,\n"
" but still recalculate the CRC so we are forced to check and detect the\n"
" invalid data appropriately.\n\n"
));

}

static int
write_f(
        int             argc,
        char            **argv)
{
        pfunc_t pf;
        extern char *progname;
        int c;
        bool corrupt = false;   /* Allow write of bad data w/ invalid CRC */
        bool invalid_data = false; /* Allow write of bad data w/ valid CRC */
        struct xfs_buf_ops local_ops;
        const struct xfs_buf_ops *stashed_ops = NULL;

        if (x.isreadonly & LIBXFS_ISREADONLY) {
                dbprintf(_("%s started in read only mode, writing disabled\n"),
                        progname);
                return 0;
        }

        if (cur_typ == NULL) {
                dbprintf(_("no current type\n"));
                return 0;
        }

        pf = cur_typ->pfunc;
        if (pf == NULL) {
                dbprintf(_("no handler function for type %s, write unsupported.\n"),
                         cur_typ->name);
                return 0;
        }

        while ((c = getopt(argc, argv, "cd")) != EOF) {
                switch (c) {
                case 'c':
                        corrupt = true;
                        break;
                case 'd':
                        invalid_data = true;
                        break;
                default:
                        dbprintf(_("bad option for write command\n"));
                        return 0;
                }
        }

        if (corrupt && invalid_data) {
                dbprintf(_("Cannot specify both -c and -d options\n"));
                return 0;
        }

        if (invalid_data &&
            iocur_top->typ->crc_off == TYP_F_NO_CRC_OFF &&
            !iocur_top->ino_buf &&
            !iocur_top->dquot_buf) {
                dbprintf(_("Cannot recalculate CRCs on this type of object\n"));
                return 0;
        }

        argc -= optind;
        argv += optind;

        /*
         * If the buffer has no verifier or we are using standard verifier
         * paths, then just write it out and return
         */
        if (!iocur_top->bp->b_ops ||
            !(corrupt || invalid_data)) {
                (*pf)(DB_WRITE, cur_typ->fields, argc, argv);
                return 0;
        }


        /* Temporarily remove write verifier to write bad data */
        stashed_ops = iocur_top->bp->b_ops;
        local_ops.verify_read = stashed_ops->verify_read;
        iocur_top->bp->b_ops = &local_ops;

        if (corrupt) {
                local_ops.verify_write = xfs_dummy_verify;
                dbprintf(_("Allowing write of corrupted data and bad CRC\n"));
        } else if (iocur_top->ino_buf) {
                local_ops.verify_write = xfs_verify_recalc_inode_crc;
                dbprintf(_("Allowing write of corrupted inode with good CRC\n"));
        } else if (iocur_top->dquot_buf) {
                local_ops.verify_write = xfs_verify_recalc_dquot_crc;
                dbprintf(_("Allowing write of corrupted dquot with good CRC\n"));
        } else if (iocur_top->typ->crc_off == TYP_F_CRC_FUNC) {
                local_ops.verify_write = iocur_top->typ->set_crc;
                dbprintf(_("Allowing write of corrupted data with good CRC\n"));
        } else { /* invalid data */
                local_ops.verify_write = xfs_verify_recalc_crc;
                dbprintf(_("Allowing write of corrupted data with good CRC\n"));
        }

        (*pf)(DB_WRITE, cur_typ->fields, argc, argv);

        iocur_top->bp->b_ops = stashed_ops;

        return 0;
}

/* compare significant portions of commands */

static int
sigcmp(
        char  *s1,
        char  *s2,
        int   sig)
{
        int sigcnt;

        if (!s1 || !s2)
                return 0;

        for (sigcnt = 0; *s1 == *s2; s1++, s2++) {
                sigcnt++;
                if (*s1 == '\0')
                        return 1;
        }
        if (*s1 && *s2)
                return 0;

        if (sig && (sigcnt >= sig))
                return 1;

        return 0;
}

/* ARGSUSED */
static void
bwrite_lshift(
        int   start,
        int   len,
        int   shift,
        int   from,
        int   to)
{
        char *base;

        if (shift == -1)
                shift = 1;
        if (start == -1)
                start = 0;
        if (len == -1)
                len = iocur_top->len - start;

        if (len+start > iocur_top->len) {
                dbprintf(_("length (%d) too large for data block size (%d)"),
                         len, iocur_top->len);
        }

        base = (char *)iocur_top->data + start;

        memcpy(base, base+shift, len-shift);
        memset(base+(len-shift), 0, shift);
}

/* ARGSUSED */
static void
bwrite_rshift(
        int   start,
        int   len,
        int   shift,
        int   from,
        int   to)
{
        char *base;

        if (shift == -1)
                shift = 1;
        if (start == -1)
                start = 0;
        if (len == -1)
                len = iocur_top->len - start;

        if (len+start > iocur_top->len) {
                dbprintf(_("length (%d) too large for data block size (%d)"),
                         len, iocur_top->len);
        }

        base = (char *)iocur_top->data + start;

        memcpy(base+shift, base, len-shift);
        memset(base, 0, shift);
}

/* ARGSUSED */
static void
bwrite_lrot(
        int   start,
        int   len,
        int   shift,
        int   from,
        int   to)
{
        char *base;
        char *hold_region;

        if (shift == -1)
                shift = 1;
        if (start == -1)
                start = 0;
        if (len == -1)
                len = iocur_top->len - start;

        if (len+start > iocur_top->len) {
                dbprintf(_("length (%d) too large for data block size (%d)"),
                         len, iocur_top->len);
        }

        base = (char *)iocur_top->data + start;

        hold_region = xmalloc(shift);
        memcpy(hold_region, base, shift);
        memcpy(base, base+shift, len-shift);
        memcpy(base+(len-shift), hold_region, shift);
        free(hold_region);
}

/* ARGSUSED */
static void
bwrite_rrot(
        int   start,
        int   len,
        int   shift,
        int   from,
        int   to)
{
        char *base;
        char *hold_region;

        if (shift == -1)
                shift = 1;
        if (start == -1)
                start = 0;
        if (len == -1)
                len = iocur_top->len - start;

        if (len+start > iocur_top->len) {
                dbprintf(_("length (%d) too large for data block size (%d)"),
                         len, iocur_top->len);
        }

        base = (char *)iocur_top->data + start;

        hold_region = xmalloc(shift);
        memcpy(hold_region, base+(len-shift), shift);
        memmove(base+shift, base, len-shift);
        memcpy(base, hold_region, shift);
        free(hold_region);
}

/* ARGSUSED */
static void
bwrite_seq(
        int   start,
        int   len,
        int   step,
        int   from,
        int   to)
{
        int i;
        int tmp;
        int base;
        int range;
        int top;
        char *buf;

        if (start == -1)
                start = 0;

        if (len == -1)
                len = iocur_top->len - start;

        if (len+start > iocur_top->len) {
                dbprintf(_("length (%d) too large for data block size (%d)"),
                         len, iocur_top->len);
        }

        if (from == -1 || from > 255)
                from = 0;
        if (to == -1 || to > 255)
                to = 255;
        if (step == -1)
                step = 1;

        base = from;
        top = to;
        if (from > to) {
                base = to;
                top = from;
                if (step > 0)
                        step = -step;
        }

        range = top - base;
        buf = (char *)iocur_top->data + start;

        tmp = 0;
        for (i = start; i < start+len; i++) {
                *buf++ = tmp + base;
                tmp = (tmp + step)%(range+1);
        }
}

/* ARGSUSED */
static void
bwrite_random(
        int   start,
        int   len,
        int   shift,
        int   from,
        int   to)
{
        int i;
        char *buf;

        if (start == -1)
                start = 0;

        if (len == -1)
                len = iocur_top->len - start;

        if (len+start > iocur_top->len) {
                dbprintf(_("length (%d) too large for data block size (%d)"),
                         len, iocur_top->len);
        }

        buf = (char *)iocur_top->data + start;

        for (i = start; i < start+len; i++)
                *buf++ = (char)lrand48();
}

/* ARGSUSED */
static void
bwrite_fill(
        int   start,
        int   len,
        int   value,
        int   from,
        int   to)
{
        char *base;

        if (value == -1)
                value = 0;
        if (start == -1)
                start = 0;
        if (len == -1)
                len = iocur_top->len - start;

        if (len+start > iocur_top->len) {
                dbprintf(_("length (%d) too large for data block size (%d)"),
                         len, iocur_top->len);
        }

        base = (char *)iocur_top->data + start;

        memset(base, value, len);
}

static struct bw_cmd {
        void    (*cmdfunc)(int,int,int,int,int);
        char    *cmdstr;
        int     sig_chars;
        int     argmin;
        int     argmax;
        int     shiftcount_arg;
        int     from_arg;
        int     to_arg;
        int     start_arg;
        int     len_arg;
        char    *usage;
} bw_cmdtab[] = {
        /* cmd   sig min max sh frm to start len */
        { bwrite_lshift, "lshift",   2, 0, 3, 1, 0, 0, 2, 3,
                "[shiftcount] [start] [len]", },
        { bwrite_rshift, "rshift",   2, 0, 3, 1, 0, 0, 2, 3,
                "[shiftcount] [start] [len]", },
        { bwrite_lrot,   "lrot",     2, 0, 3, 1, 0, 0, 2, 3,
                "[shiftcount] [start] [len]", },
        { bwrite_rrot,   "rrot",     2, 0, 3, 1, 0, 0, 2, 3,
                "[shiftcount] [start] [len]", },
        { bwrite_seq,    "sequence", 3, 0, 4, 0, 1, 2, 3, 4,
                "[from] [to] [start] [len]", },
        { bwrite_random, "random",   3, 0, 2, 0, 0, 0, 1, 2,
                "[start] [len]", },
        { bwrite_fill,   "fill",     1, 1, 3, 1, 0, 0, 2, 3,
                "num [start] [len]" }
};

#define BWRITE_CMD_MAX (sizeof(bw_cmdtab)/sizeof(bw_cmdtab[0]))

static int
convert_oct(
        char *arg,
        int  *ret)
{
        int count;
        int i;
        int val = 0;

        /* only allow 1 case, '\' and 3 octal digits (or less) */

        for (count = 0; count < 3; count++) {
                if (arg[count] == '\0')
                        break;

                if ((arg[count] < '0') && (arg[count] > '7'))
                        break;
        }

        for (i = 0; i < count; i++) {
                val |= ((arg[(count-1)-i]-'0')&0x07)<<(i*3);
        }

        *ret = val&0xff;

        return(count);
}

#define NYBBLE(x) (isdigit(x)?(x-'0'):(tolower(x)-'a'+0xa))

/*
 * convert_arg allows input in the following forms:
 *
 *      - A string ("ABTB") whose ASCII value is placed in an array in the order
 *      matching the input.
 *
 *      - An even number of hex numbers. If the length is greater than 64 bits,
 *      then the output is an array of bytes whose top nibble is the first hex
 *      digit in the input, the lower nibble is the second hex digit in the
 *      input. UUID entries are entered in this manner.
 *
 *      - A decimal or hexadecimal integer to be used with setbitval().
 *
 * Numbers that are passed to setbitval() need to be in big endian format and
 * are adjusted in the buffer so that the first input bit is to be be written to
 * the first bit in the output.
 */
static char *
convert_arg(
        char            *arg,
        int             bit_length)
{
        int             i;
        int             alloc_size;
        int             octval;
        int             offset;
        int             ret;
        static char     *buf = NULL;
        char            *endp;
        char            *rbuf;
        char            *ostr;
        __u64           *value;
        __u64           val = 0;

        if (bit_length <= 64)
                alloc_size = 8;
        else
                alloc_size = (bit_length + 7) / 8;

        buf = xrealloc(buf, alloc_size);
        memset(buf, 0, alloc_size);
        value = (__u64 *)buf;
        rbuf = buf;

        if (*arg == '\"') {
                /* input a string and output ASCII array of characters */

                /* zap closing quote if there is one */
                ostr = strrchr(arg + 1, '\"');
                if (ostr)
                        *ostr = '\0';

                ostr = arg + 1;
                for (i = 0; i < alloc_size; i++) {
                        if (!*ostr)
                                break;

                        /* do octal conversion */
                        if (*ostr == '\\') {
                                if (*(ostr + 1) >= '0' || *(ostr + 1) <= '7') {
                                        ret = convert_oct(ostr + 1, &octval);
                                        *rbuf++ = octval;
                                        ostr += ret + 1;
                                        continue;
                                }
                        }
                        *rbuf++ = *ostr++;
                }
                return buf;
        }

        if (arg[0] == '#' || ((arg[0] != '-') && strchr(arg,'-'))) {
                /*
                 * handle hex blocks ie
                 *    #00112233445566778899aabbccddeeff
                 * and uuids ie
                 *    1122334455667788-99aa-bbcc-ddee-ff00112233445566778899
                 *
                 * (but if it starts with "-" assume it's just an integer)
                 */
                int bytes = bit_length / NBBY;

                /* is this an array of hec numbers? */
                if (bit_length % NBBY)
                        return NULL;

                /* skip leading hash */
                if (*arg == '#')
                        arg++;

                while (*arg && bytes--) {
                        /* skip hypens */
                        while (*arg == '-')
                                arg++;

                        /* get first nybble */
                        if (!isxdigit((int)*arg))
                                return NULL;
                        *rbuf = NYBBLE((int)*arg) << 4;
                        arg++;

                        /* skip more hyphens */
                        while (*arg == '-')
                                arg++;

                        /* get second nybble */
                        if (!isxdigit((int)*arg))
                                return NULL;
                        *rbuf++ |= NYBBLE((int)*arg);
                        arg++;
                }
                if (bytes < 0 && *arg)
                        return NULL;

                return buf;
        }

        /* handle decimal / hexadecimal integers */
        val = strtoll(arg, &endp, 0);
        /* return if not a clean number */
        if (*endp != '\0')
                return NULL;

        /* Does the value fit into the range of the destination bitfield? */
        if (bit_length < 64 && (val >> bit_length) > 0)
                return NULL;
        /*
         * If the length of the field is not a multiple of a byte, push
         * the bits up in the field, so the most signicant field bit is
         * the most significant bit in the byte:
         *
         * before:
         * val  |----|----|----|----|----|--MM|mmmm|llll|
         * after
         * val  |----|----|----|----|----|MMmm|mmll|ll00|
         */
        offset = bit_length % NBBY;
        if (offset)
                val <<= (NBBY - offset);

        /*
         * convert to big endian and copy into the array
         * rbuf |----|----|----|----|----|MMmm|mmll|ll00|
         */
        *value = cpu_to_be64(val);

        /*
         * Align the array to point to the field in the array.
         *  rbuf  = |MMmm|mmll|ll00|
         */
        offset = sizeof(__be64) - 1 - ((bit_length - 1) / sizeof(__be64));
        rbuf += offset;
        return rbuf;
}


/* ARGSUSED */
void
write_struct(
        const field_t   *fields,
        int             argc,
        char            **argv)
{
        const ftattr_t  *fa;
        flist_t         *fl;
        flist_t         *sfl;
        int             bit_length;
        char            *buf;
        int             parentoffset;

        if (argc != 2) {
                dbprintf(_("usage: write fieldname value\n"));
                return;
        }

        fl = flist_scan(argv[0]);
        if (!fl) {
                dbprintf(_("unable to parse '%s'.\n"), argv[0]);
                return;
        }

        /* if we're a root field type, go down 1 layer to get field list */
        if (fields->name[0] == '\0') {
                fa = &ftattrtab[fields->ftyp];
                ASSERT(fa->ftyp == fields->ftyp);
                fields = fa->subfld;
        }

        /* run down the field list and set offsets into the data */
        if (!flist_parse(fields, fl, iocur_top->data, 0)) {
                flist_free(fl);
                dbprintf(_("parsing error\n"));
                return;
        }

        sfl = fl;
        parentoffset = 0;
        while (sfl->child) {
                parentoffset = sfl->offset;
                sfl = sfl->child;
        }

        /*
         * For structures, fsize * fcount tells us the size of the region we are
         * modifying, which is usually a single structure member and is pointed
         * to by the last child in the list.
         *
         * However, if the base structure is an array and we have a direct index
         * into the array (e.g. write bno[5]) then we are returned a single
         * flist object with the offset pointing directly at the location we
         * need to modify. The length of the object we are modifying is then
         * determined by the size of the individual array entry (fsize) and the
         * indexes defined in the object, not the overall size of the array
         * (which is what fcount returns).
         */
        bit_length = fsize(sfl->fld, iocur_top->data, parentoffset, 0);
        if (sfl->fld->flags & FLD_ARRAY)
                bit_length *= sfl->high - sfl->low + 1;
        else
                bit_length *= fcount(sfl->fld, iocur_top->data, parentoffset);

        /* convert this to a generic conversion routine */
        /* should be able to handle str, num, or even labels */

        buf = convert_arg(argv[1], bit_length);
        if (!buf) {
                dbprintf(_("unable to convert value '%s'.\n"), argv[1]);
                flist_free(fl);
                return;
        }

        setbitval(iocur_top->data, sfl->offset, bit_length, buf);
        write_cur();

        flist_print(fl);
        print_flist(fl);
        flist_free(fl);
}

/* ARGSUSED */
void
write_string(
        const field_t   *fields,
        int             argc,
        char            **argv)
{
        char *buf;
        int i;

        if (argc != 1) {
                dbprintf(_("usage (in string mode): write \"string...\"\n"));
                return;
        }

        buf = convert_arg(argv[0], (int)((strlen(argv[0])+1)*8));
        for (i = 0; i < iocur_top->len; i++) {
                ((char *)iocur_top->data)[i] = *buf;
                if (*buf++ == '\0')
                        break;
        }

        /* write back to disk */
        write_cur();
}

/* ARGSUSED */
void
write_block(
        const field_t   *fields,
        int             argc,
        char            **argv)
{
        int i;
        int shiftcount = -1;
        int start = -1;
        int len = -1;
        int from = -1;
        int to = -1;
        struct bw_cmd *cmd = NULL;

        if (argc <= 1 || argc > 5)
                goto block_usage;

        for (i = 0; i < BWRITE_CMD_MAX; i++) {
                if (sigcmp(argv[0], bw_cmdtab[i].cmdstr,
                           bw_cmdtab[i].sig_chars)) {
                        cmd = &bw_cmdtab[i];
                        break;
                }
        }

        if (!cmd) {
                dbprintf(_("write: invalid subcommand\n"));
                goto block_usage;
        }

        if ((argc < cmd->argmin + 1) || (argc > cmd->argmax + 1)) {
                dbprintf(_("write %s: invalid number of arguments\n"),
                         cmd->cmdstr);
                goto block_usage;
        }

        if (cmd->shiftcount_arg && (cmd->shiftcount_arg < argc))
                shiftcount = (int)strtoul(argv[cmd->shiftcount_arg], NULL, 0);
        if (cmd->start_arg && (cmd->start_arg < argc))
                start =  (int)strtoul(argv[cmd->start_arg], NULL, 0);
        if (cmd->len_arg && (cmd->len_arg < argc))
                len = (int)strtoul(argv[cmd->len_arg], NULL, 0);
        if (cmd->from_arg  && (cmd->len_arg < argc))
                from = (int)strtoul(argv[cmd->from_arg], NULL, 0);
        if (cmd->to_arg && (cmd->len_arg < argc))
                to = (int)strtoul(argv[cmd->to_arg], NULL, 0);

        cmd->cmdfunc(start, len, shiftcount, from, to);

        /* write back to disk */
        write_cur();
        return;

  block_usage:

        dbprintf(_("usage: write (in data mode)\n"));
        for (i = 0; i < BWRITE_CMD_MAX; i++) {
                dbprintf("              %-9.9s %s\n",
                         bw_cmdtab[i].cmdstr, bw_cmdtab[i].usage);
        }
        dbprintf("\n");
        return;
}