/*
 *  linux/fs/hpfs/name.c
 *
 *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
 *
 *  operations with filenames
 */

#include <linux/string.h>
#include "hpfs_fn.h"

char *text_postfix[]={
".ASM", ".BAS", ".BAT", ".C", ".CC", ".CFG", ".CMD", ".CON", ".CPP", ".DEF",
".DOC", ".DPR", ".ERX", ".H", ".HPP", ".HTM", ".HTML", ".JAVA", ".LOG", ".PAS",
".RC", ".TEX", ".TXT", ".Y", ""};

char *text_prefix[]={
"AUTOEXEC.", "CHANGES", "COPYING", "CONFIG.", "CREDITS", "FAQ", "FILE_ID.DIZ",
"MAKEFILE", "READ.ME", "README", "TERMCAP", ""};

void hpfs_decide_conv(struct inode *inode, unsigned char *name, unsigned len)
{
	int i;
	if (inode->i_hpfs_conv != CONV_AUTO) return;
	for (i = 0; *text_postfix[i]; i++) {
		int l = strlen(text_postfix[i]);
		if (l <= len)
			if (!hpfs_compare_names(inode->i_sb, text_postfix[i], l, name + len - l, l, 0))
				goto text;
	}
	for (i = 0; *text_prefix[i]; i++) {
		int l = strlen(text_prefix[i]);
		if (l <= len)
			if (!hpfs_compare_names(inode->i_sb, text_prefix[i], l, name, l, 0))
				goto text;
	}
	inode->i_hpfs_conv = CONV_BINARY;
	return;
	text:
	inode->i_hpfs_conv = CONV_TEXT;
	return;
}

static inline int not_allowed_char(unsigned char c)
{
	return c<' ' || c=='"' || c=='*' || c=='/' || c==':' || c=='<' ||
	      c=='>' || c=='?' || c=='\\' || c=='|';
}

static inline int no_dos_char(unsigned char c)
{	/* Characters that are allowed in HPFS but not in DOS */
	return c=='+' || c==',' || c==';' || c=='=' || c=='[' || c==']';
}

static inline unsigned char upcase(unsigned char *dir, unsigned char a)
{
	if (a<128 || a==255) return a>='a' && a<='z' ? a - 0x20 : a;
	if (!dir) return a;
	return dir[a-128];
}

unsigned char hpfs_upcase(unsigned char *dir, unsigned char a)
{
	return upcase(dir, a);
}

static inline unsigned char locase(unsigned char *dir, unsigned char a)
{
	if (a<128 || a==255) return a>='A' && a<='Z' ? a + 0x20 : a;
	if (!dir) return a;
	return dir[a];
}

int hpfs_chk_name(unsigned char *name, unsigned *len)
{
	int i;
	if (*len > 254) return -ENAMETOOLONG;
	hpfs_adjust_length(name, len);
	if (!*len) return -EINVAL;
	for (i = 0; i < *len; i++) if (not_allowed_char(name[i])) return -EINVAL;
	if (*len == 1) if (name[0] == '.') return -EINVAL;
	if (*len == 2) if (name[0] == '.' && name[1] == '.') return -EINVAL;
	return 0;
}

char *hpfs_translate_name(struct super_block *s, unsigned char *from,
			  unsigned len, int lc, int lng)
{
	char *to;
	int i;
	if (s->s_hpfs_chk >= 2) if (hpfs_is_name_long(from, len) != lng) {
		printk("HPFS: Long name flag mismatch - name ");
		for (i=0; i<len; i++) printk("%c", from[i]);
		printk(" misidentified as %s.\n", lng ? "short" : "long");
		printk("HPFS: It's nothing serious. It could happen because of bug in OS/2.\nHPFS: Set checks=normal to disable this message.\n");
	}
	if (!lc) return from;
	if (!(to = kmalloc(len, GFP_KERNEL))) {
		printk("HPFS: can't allocate memory for name conversion buffer\n");
		return from;
	}
	for (i = 0; i < len; i++) to[i] = locase(s->s_hpfs_cp_table,from[i]);
	return to;
}

int hpfs_compare_names(struct super_block *s, unsigned char *n1, unsigned l1,
		       unsigned char *n2, unsigned l2, int last)
{
	unsigned l = l1 < l2 ? l1 : l2;
	unsigned i;
	if (last) return -1;
	for (i = 0; i < l; i++) {
		unsigned char c1 = upcase(s->s_hpfs_cp_table,n1[i]);
		unsigned char c2 = upcase(s->s_hpfs_cp_table,n2[i]);
		if (c1 < c2) return -1;
		if (c1 > c2) return 1;
	}
	if (l1 < l2) return -1;
	if (l1 > l2) return 1;
	return 0;
}

int hpfs_is_name_long(unsigned char *name, unsigned len)
{
	int i,j;
	for (i = 0; i < len && name[i] != '.'; i++)
		if (no_dos_char(name[i])) return 1;
	if (!i || i > 8) return 1;
	if (i == len) return 0;
	for (j = i + 1; j < len; j++)
		if (name[j] == '.' || no_dos_char(name[i])) return 1;
	return j - i > 4;
}

/* OS/2 clears dots and spaces at the end of file name, so we have to */

void hpfs_adjust_length(unsigned char *name, unsigned *len)
{
	if (!*len) return;
	if (*len == 1 && name[0] == '.') return;
	if (*len == 2 && name[0] == '.' && name[1] == '.') return;
	while (*len && (name[*len - 1] == '.' || name[*len - 1] == ' '))
		(*len)--;
}