1 files changed, 502 insertions, 0 deletions

diff --git a/dosfstools/src/lfn.c b/dosfstools/src/lfn.c
new file mode 100644
index 000000000..736491cb0
--- /dev/null
+++ b/dosfstools/src/lfn.c
@@ -0,0 +1,502 @@
+/* lfn.c - Functions for handling VFAT long filenames
+
+   Copyright (C) 1998 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de>
+
+   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, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will 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, see <http://www.gnu.org/licenses/>.
+
+   On Debian systems, the complete text of the GNU General Public License
+   can be found in /usr/share/common-licenses/GPL-3 file.
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <limits.h>
+#include <time.h>
+
+#include "common.h"
+#include "io.h"
+#include "dosfsck.h"
+#include "lfn.h"
+#include "file.h"
+
+typedef struct {
+    __u8 id;			/* sequence number for slot */
+    __u8 name0_4[10];		/* first 5 characters in name */
+    __u8 attr;			/* attribute byte */
+    __u8 reserved;		/* always 0 */
+    __u8 alias_checksum;	/* checksum for 8.3 alias */
+    __u8 name5_10[12];		/* 6 more characters in name */
+    __u16 start;		/* starting cluster number, 0 in long slots */
+    __u8 name11_12[4];		/* last 2 characters in name */
+} LFN_ENT;
+
+#define LFN_ID_START	0x40
+#define LFN_ID_SLOTMASK	0x1f
+
+#define CHARS_PER_LFN	13
+
+/* These modul-global vars represent the state of the LFN parser */
+unsigned char *lfn_unicode = NULL;
+unsigned char lfn_checksum;
+int lfn_slot = -1;
+loff_t *lfn_offsets = NULL;
+int lfn_parts = 0;
+
+static unsigned char fat_uni2esc[64] = {
+    '0', '1', '2', '3', '4', '5', '6', '7',
+    '8', '9', 'A', 'B', 'C', 'D', 'E', 'F',
+    'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N',
+    'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V',
+    'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd',
+    'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l',
+    'm', 'n', 'o', 'p', 'q', 'r', 's', 't',
+    'u', 'v', 'w', 'x', 'y', 'z', '+', '-'
+};
+
+/* This defines which unicode chars are directly convertable to ISO-8859-1 */
+#define UNICODE_CONVERTABLE(cl,ch)	(ch == 0 && (cl < 0x80 || cl >= 0xa0))
+
+/* for maxlen param */
+#define UNTIL_0		INT_MAX
+
+/* Convert name part in 'lfn' from unicode to ASCII */
+#define CNV_THIS_PART(lfn)				\
+    ({							\
+	unsigned char __part_uni[CHARS_PER_LFN*2];		\
+	copy_lfn_part( __part_uni, lfn );		\
+	cnv_unicode( __part_uni, CHARS_PER_LFN, 0 );	\
+    })
+
+/* Convert name parts collected so far (from previous slots) from unicode to
+ * ASCII */
+#define CNV_PARTS_SO_FAR()					\
+	(cnv_unicode( lfn_unicode+(lfn_slot*CHARS_PER_LFN*2),	\
+		      lfn_parts*CHARS_PER_LFN, 0 ))
+
+/* This function converts an unicode string to a normal ASCII string, assuming
+ * ISO-8859-1 charset. Characters not in 8859-1 are converted to the same
+ * escape notation as used by the kernel, i.e. the uuencode-like ":xxx" */
+static char *cnv_unicode(const unsigned char *uni, int maxlen, int use_q)
+{
+    const unsigned char *up;
+    unsigned char *out, *cp;
+    int len, val;
+
+    for (len = 0, up = uni; (up - uni) / 2 < maxlen && (up[0] || up[1]);
+	 up += 2) {
+	if (UNICODE_CONVERTABLE(up[0], up[1]))
+	    ++len;
+	else
+	    len += 4;
+    }
+    cp = out = use_q ? qalloc(&mem_queue, len + 1) : alloc(len + 1);
+
+    for (up = uni; (up - uni) / 2 < maxlen && (up[0] || up[1]); up += 2) {
+	if (UNICODE_CONVERTABLE(up[0], up[1]))
+	    *cp++ = up[0];
+	else {
+	    /* here the same escape notation is used as in the Linux kernel */
+	    *cp++ = ':';
+	    val = (up[1] << 8) + up[0];
+	    cp[2] = fat_uni2esc[val & 0x3f];
+	    val >>= 6;
+	    cp[1] = fat_uni2esc[val & 0x3f];
+	    val >>= 6;
+	    cp[0] = fat_uni2esc[val & 0x3f];
+	    cp += 3;
+	}
+    }
+    *cp = 0;
+
+    return (char *)out;
+}
+
+static void copy_lfn_part(unsigned char *dst, LFN_ENT * lfn)
+{
+    memcpy(dst, lfn->name0_4, 10);
+    memcpy(dst + 10, lfn->name5_10, 12);
+    memcpy(dst + 22, lfn->name11_12, 4);
+}
+
+static void clear_lfn_slots(int start, int end)
+{
+    int i;
+    LFN_ENT empty;
+
+    /* New dir entry is zeroed except first byte, which is set to 0xe5.
+     * This is to avoid that some FAT-reading OSes (not Linux! ;) stop reading
+     * a directory at the first zero entry...
+     */
+    memset(&empty, 0, sizeof(empty));
+    empty.id = DELETED_FLAG;
+
+    for (i = start; i <= end; ++i) {
+	fs_write(lfn_offsets[i], sizeof(LFN_ENT), &empty);
+    }
+}
+
+void lfn_fix_checksum(loff_t from, loff_t to, const char *short_name)
+{
+    int i;
+    __u8 sum;
+    for (sum = 0, i = 0; i < 11; i++)
+	sum = (((sum & 1) << 7) | ((sum & 0xfe) >> 1)) + short_name[i];
+
+    for (; from < to; from += sizeof(LFN_ENT)) {
+	fs_write(from + offsetof(LFN_ENT, alias_checksum), sizeof(sum), &sum);
+    }
+}
+
+void lfn_reset(void)
+{
+    if (lfn_unicode)
+	free(lfn_unicode);
+    lfn_unicode = NULL;
+    if (lfn_offsets)
+	free(lfn_offsets);
+    lfn_offsets = NULL;
+    lfn_slot = -1;
+}
+
+/* This function is only called with de->attr == VFAT_LN_ATTR. It stores part
+ * of the long name. */
+void lfn_add_slot(DIR_ENT * de, loff_t dir_offset)
+{
+    LFN_ENT *lfn = (LFN_ENT *) de;
+    int slot = lfn->id & LFN_ID_SLOTMASK;
+    unsigned offset;
+
+    if (lfn_slot == 0)
+	lfn_check_orphaned();
+
+    if (de->attr != VFAT_LN_ATTR)
+	die("lfn_add_slot called with non-LFN directory entry");
+
+    if (lfn->id & LFN_ID_START && slot != 0) {
+	if (lfn_slot != -1) {
+	    int can_clear = 0;
+	    /* There is already a LFN "in progess", so it is an error that a
+	     * new start entry is here. */
+	    /* Causes: 1) if slot# == expected: start bit set mysteriously, 2)
+	     *         old LFN overwritten by new one */
+	    /* Fixes: 1) delete previous LFN 2) if slot# == expected and
+	     *        checksum ok: clear start bit */
+	    /* XXX: Should delay that until next LFN known (then can better
+	     * display the name) */
+	    printf("A new long file name starts within an old one.\n");
+	    if (slot == lfn_slot && lfn->alias_checksum == lfn_checksum) {
+		char *part1 = CNV_THIS_PART(lfn);
+		char *part2 = CNV_PARTS_SO_FAR();
+		printf("  It could be that the LFN start bit is wrong here\n"
+		       "  if \"%s\" seems to match \"%s\".\n", part1, part2);
+		free(part1);
+		free(part2);
+		can_clear = 1;
+	    }
+	    if (interactive) {
+		printf("1: Delete previous LFN\n2: Leave it as it is.\n");
+		if (can_clear)
+		    printf("3: Clear start bit and concatenate LFNs\n");
+	    } else
+		printf("  Not auto-correcting this.\n");
+	    if (interactive) {
+		switch (get_key(can_clear ? "123" : "12", "?")) {
+		case '1':
+		    clear_lfn_slots(0, lfn_parts - 1);
+		    lfn_reset();
+		    break;
+		case '2':
+		    break;
+		case '3':
+		    lfn->id &= ~LFN_ID_START;
+		    fs_write(dir_offset + offsetof(LFN_ENT, id),
+			     sizeof(lfn->id), &lfn->id);
+		    break;
+		}
+	    }
+	}
+	lfn_slot = slot;
+	lfn_checksum = lfn->alias_checksum;
+	lfn_unicode = alloc((lfn_slot * CHARS_PER_LFN + 1) * 2);
+	lfn_offsets = alloc(lfn_slot * sizeof(loff_t));
+	lfn_parts = 0;
+    } else if (lfn_slot == -1 && slot != 0) {
+	/* No LFN in progress, but slot found; start bit missing */
+	/* Causes: 1) start bit got lost, 2) Previous slot with start bit got
+	 *         lost */
+	/* Fixes: 1) delete LFN, 2) set start bit */
+	char *part = CNV_THIS_PART(lfn);
+	printf("Long filename fragment \"%s\" found outside a LFN "
+	       "sequence.\n  (Maybe the start bit is missing on the "
+	       "last fragment)\n", part);
+	if (interactive) {
+	    printf("1: Delete fragment\n2: Leave it as it is.\n"
+		   "3: Set start bit\n");
+	} else
+	    printf("  Not auto-correcting this.\n");
+	switch (interactive ? get_key("123", "?") : '2') {
+	case '1':
+	    if (!lfn_offsets)
+		lfn_offsets = alloc(sizeof(loff_t));
+	    lfn_offsets[0] = dir_offset;
+	    clear_lfn_slots(0, 0);
+	    lfn_reset();
+	    return;
+	case '2':
+	    lfn_reset();
+	    return;
+	case '3':
+	    lfn->id |= LFN_ID_START;
+	    fs_write(dir_offset + offsetof(LFN_ENT, id),
+		     sizeof(lfn->id), &lfn->id);
+	    lfn_slot = slot;
+	    lfn_checksum = lfn->alias_checksum;
+	    lfn_unicode = alloc((lfn_slot * CHARS_PER_LFN + 1) * 2);
+	    lfn_offsets = alloc(lfn_slot * sizeof(loff_t));
+	    lfn_parts = 0;
+	    break;
+	}
+    } else if (slot != lfn_slot) {
+	/* wrong sequence number */
+	/* Causes: 1) seq-no destroyed */
+	/* Fixes: 1) delete LFN, 2) fix number (maybe only if following parts
+	 *        are ok?, maybe only if checksum is ok?) (Attention: space
+	 *        for name was allocated before!) */
+	int can_fix = 0;
+	printf("Unexpected long filename sequence number "
+	       "(%d vs. expected %d).\n", slot, lfn_slot);
+	if (lfn->alias_checksum == lfn_checksum && lfn_slot > 0) {
+	    char *part1 = CNV_THIS_PART(lfn);
+	    char *part2 = CNV_PARTS_SO_FAR();
+	    printf("  It could be that just the number is wrong\n"
+		   "  if \"%s\" seems to match \"%s\".\n", part1, part2);
+	    free(part1);
+	    free(part2);
+	    can_fix = 1;
+	}
+	if (interactive) {
+	    printf
+		("1: Delete LFN\n2: Leave it as it is (and ignore LFN so far)\n");
+	    if (can_fix)
+		printf("3: Correct sequence number\n");
+	} else
+	    printf("  Not auto-correcting this.\n");
+	switch (interactive ? get_key(can_fix ? "123" : "12", "?") : '2') {
+	case '1':
+	    if (!lfn_offsets) {
+		lfn_offsets = alloc(sizeof(loff_t));
+		lfn_parts = 0;
+	    }
+	    lfn_offsets[lfn_parts++] = dir_offset;
+	    clear_lfn_slots(0, lfn_parts - 1);
+	    lfn_reset();
+	    return;
+	case '2':
+	    lfn_reset();
+	    return;
+	case '3':
+	    lfn->id = (lfn->id & ~LFN_ID_SLOTMASK) | lfn_slot;
+	    fs_write(dir_offset + offsetof(LFN_ENT, id),
+		     sizeof(lfn->id), &lfn->id);
+	    break;
+	}
+    }
+
+    if (lfn->alias_checksum != lfn_checksum) {
+	/* checksum mismatch */
+	/* Causes: 1) checksum field here destroyed */
+	/* Fixes: 1) delete LFN, 2) fix checksum */
+	printf("Checksum in long filename part wrong "
+	       "(%02x vs. expected %02x).\n",
+	       lfn->alias_checksum, lfn_checksum);
+	if (interactive) {
+	    printf("1: Delete LFN\n2: Leave it as it is.\n"
+		   "3: Correct checksum\n");
+	} else
+	    printf("  Not auto-correcting this.\n");
+	if (interactive) {
+	    switch (get_key("123", "?")) {
+	    case '1':
+		lfn_offsets[lfn_parts++] = dir_offset;
+		clear_lfn_slots(0, lfn_parts - 1);
+		lfn_reset();
+		return;
+	    case '2':
+		break;
+	    case '3':
+		lfn->alias_checksum = lfn_checksum;
+		fs_write(dir_offset + offsetof(LFN_ENT, alias_checksum),
+			 sizeof(lfn->alias_checksum), &lfn->alias_checksum);
+		break;
+	    }
+	}
+    }
+
+    if (lfn_slot != -1) {
+	lfn_slot--;
+	offset = lfn_slot * CHARS_PER_LFN * 2;
+	copy_lfn_part(lfn_unicode + offset, lfn);
+	if (lfn->id & LFN_ID_START)
+	    lfn_unicode[offset + 26] = lfn_unicode[offset + 27] = 0;
+	lfn_offsets[lfn_parts++] = dir_offset;
+    }
+
+    if (lfn->reserved != 0) {
+	printf("Reserved field in VFAT long filename slot is not 0 "
+	       "(but 0x%02x).\n", lfn->reserved);
+	if (interactive)
+	    printf("1: Fix.\n2: Leave it.\n");
+	else
+	    printf("Auto-setting to 0.\n");
+	if (!interactive || get_key("12", "?") == '1') {
+	    lfn->reserved = 0;
+	    fs_write(dir_offset + offsetof(LFN_ENT, reserved),
+		     sizeof(lfn->reserved), &lfn->reserved);
+	}
+    }
+    if (lfn->start != CT_LE_W(0)) {
+	printf("Start cluster field in VFAT long filename slot is not 0 "
+	       "(but 0x%04x).\n", lfn->start);
+	if (interactive)
+	    printf("1: Fix.\n2: Leave it.\n");
+	else
+	    printf("Auto-setting to 0.\n");
+	if (!interactive || get_key("12", "?") == '1') {
+	    lfn->start = CT_LE_W(0);
+	    fs_write(dir_offset + offsetof(LFN_ENT, start),
+		     sizeof(lfn->start), &lfn->start);
+	}
+    }
+}
+
+/* This function is always called when de->attr != VFAT_LN_ATTR is found, to
+ * retrieve the previously constructed LFN. */
+char *lfn_get(DIR_ENT * de, loff_t * lfn_offset)
+{
+    char *lfn;
+    __u8 sum;
+    int i;
+
+    *lfn_offset = 0;
+    if (de->attr == VFAT_LN_ATTR)
+	die("lfn_get called with LFN directory entry");
+
+#if 0
+    if (de->lcase)
+	printf("lcase=%02x\n", de->lcase);
+#endif
+
+    if (lfn_slot == -1)
+	/* no long name for this file */
+	return NULL;
+
+    if (lfn_slot != 0) {
+	/* The long name isn't finished yet. */
+	/* Causes: 1) LFN slot overwritten by non-VFAT aware tool */
+	/* Fixes: 1) delete LFN 2) move overwriting entry to somewhere else
+	 * and let user enter missing part of LFN (hard to do :-()
+	 * 3) renumber entries and truncate name */
+	char *long_name = CNV_PARTS_SO_FAR();
+	char *short_name = file_name(de->name);
+	printf("Unfinished long file name \"%s\".\n"
+	       "  (Start may have been overwritten by %s)\n",
+	       long_name, short_name);
+	free(long_name);
+	if (interactive) {
+	    printf("1: Delete LFN\n2: Leave it as it is.\n"
+		   "3: Fix numbering (truncates long name and attaches "
+		   "it to short name %s)\n", short_name);
+	} else
+	    printf("  Not auto-correcting this.\n");
+	switch (interactive ? get_key("123", "?") : '2') {
+	case '1':
+	    clear_lfn_slots(0, lfn_parts - 1);
+	    lfn_reset();
+	    return NULL;
+	case '2':
+	    lfn_reset();
+	    return NULL;
+	case '3':
+	    for (i = 0; i < lfn_parts; ++i) {
+		__u8 id = (lfn_parts - i) | (i == 0 ? LFN_ID_START : 0);
+		fs_write(lfn_offsets[i] + offsetof(LFN_ENT, id),
+			 sizeof(id), &id);
+	    }
+	    memmove(lfn_unicode, lfn_unicode + lfn_slot * CHARS_PER_LFN * 2,
+		    lfn_parts * CHARS_PER_LFN * 2);
+	    break;
+	}
+    }
+
+    for (sum = 0, i = 0; i < 11; i++)
+	sum = (((sum & 1) << 7) | ((sum & 0xfe) >> 1)) + de->name[i];
+    if (sum != lfn_checksum) {
+	/* checksum doesn't match, long name doesn't apply to this alias */
+	/* Causes: 1) alias renamed */
+	/* Fixes: 1) Fix checksum in LFN entries */
+	char *long_name = CNV_PARTS_SO_FAR();
+	char *short_name = file_name(de->name);
+	printf("Wrong checksum for long file name \"%s\".\n"
+	       "  (Short name %s may have changed without updating the long name)\n",
+	       long_name, short_name);
+	free(long_name);
+	if (interactive) {
+	    printf("1: Delete LFN\n2: Leave it as it is.\n"
+		   "3: Fix checksum (attaches to short name %s)\n", short_name);
+	} else
+	    printf("  Not auto-correcting this.\n");
+	if (interactive) {
+	    switch (get_key("123", "?")) {
+	    case '1':
+		clear_lfn_slots(0, lfn_parts - 1);
+		lfn_reset();
+		return NULL;
+	    case '2':
+		lfn_reset();
+		return NULL;
+	    case '3':
+		for (i = 0; i < lfn_parts; ++i) {
+		    fs_write(lfn_offsets[i] + offsetof(LFN_ENT, alias_checksum),
+			     sizeof(sum), &sum);
+		}
+		break;
+	    }
+	}
+    }
+
+    *lfn_offset = lfn_offsets[0];
+    lfn = cnv_unicode(lfn_unicode, UNTIL_0, 1);
+    lfn_reset();
+    return (lfn);
+}
+
+void lfn_check_orphaned(void)
+{
+    char *long_name;
+
+    if (lfn_slot == -1)
+	return;
+
+    long_name = CNV_PARTS_SO_FAR();
+    printf("Orphaned long file name part \"%s\"\n", long_name);
+    if (interactive)
+	printf("1: Delete.\n2: Leave it.\n");
+    else
+	printf("  Auto-deleting.\n");
+    if (!interactive || get_key("12", "?") == '1') {
+	clear_lfn_slots(0, lfn_parts - 1);
+    }
+    lfn_reset();
+}