xref: /openbmc/linux/fs/hpfs/name.c (revision b2441318)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  linux/fs/hpfs/name.c
4  *
5  *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
6  *
7  *  operations with filenames
8  */
9 
10 #include "hpfs_fn.h"
11 
not_allowed_char(unsigned char c)12 static inline int not_allowed_char(unsigned char c)
13 {
14 	return c<' ' || c=='"' || c=='*' || c=='/' || c==':' || c=='<' ||
15 	      c=='>' || c=='?' || c=='\\' || c=='|';
16 }
17 
no_dos_char(unsigned char c)18 static inline int no_dos_char(unsigned char c)
19 {	/* Characters that are allowed in HPFS but not in DOS */
20 	return c=='+' || c==',' || c==';' || c=='=' || c=='[' || c==']';
21 }
22 
upcase(unsigned char * dir,unsigned char a)23 static inline unsigned char upcase(unsigned char *dir, unsigned char a)
24 {
25 	if (a<128 || a==255) return a>='a' && a<='z' ? a - 0x20 : a;
26 	if (!dir) return a;
27 	return dir[a-128];
28 }
29 
hpfs_upcase(unsigned char * dir,unsigned char a)30 unsigned char hpfs_upcase(unsigned char *dir, unsigned char a)
31 {
32 	return upcase(dir, a);
33 }
34 
locase(unsigned char * dir,unsigned char a)35 static inline unsigned char locase(unsigned char *dir, unsigned char a)
36 {
37 	if (a<128 || a==255) return a>='A' && a<='Z' ? a + 0x20 : a;
38 	if (!dir) return a;
39 	return dir[a];
40 }
41 
hpfs_chk_name(const unsigned char * name,unsigned * len)42 int hpfs_chk_name(const unsigned char *name, unsigned *len)
43 {
44 	int i;
45 	if (*len > 254) return -ENAMETOOLONG;
46 	hpfs_adjust_length(name, len);
47 	if (!*len) return -EINVAL;
48 	for (i = 0; i < *len; i++) if (not_allowed_char(name[i])) return -EINVAL;
49 	if (*len == 1) if (name[0] == '.') return -EINVAL;
50 	if (*len == 2) if (name[0] == '.' && name[1] == '.') return -EINVAL;
51 	return 0;
52 }
53 
hpfs_translate_name(struct super_block * s,unsigned char * from,unsigned len,int lc,int lng)54 unsigned char *hpfs_translate_name(struct super_block *s, unsigned char *from,
55 			  unsigned len, int lc, int lng)
56 {
57 	unsigned char *to;
58 	int i;
59 	if (hpfs_sb(s)->sb_chk >= 2) if (hpfs_is_name_long(from, len) != lng) {
60 		pr_err("Long name flag mismatch - name ");
61 		for (i = 0; i < len; i++)
62 			pr_cont("%c", from[i]);
63 		pr_cont(" misidentified as %s.\n", lng ? "short" : "long");
64 		pr_err("It's nothing serious. It could happen because of bug in OS/2.\nSet checks=normal to disable this message.\n");
65 	}
66 	if (!lc) return from;
67 	if (!(to = kmalloc(len, GFP_KERNEL))) {
68 		pr_err("can't allocate memory for name conversion buffer\n");
69 		return from;
70 	}
71 	for (i = 0; i < len; i++) to[i] = locase(hpfs_sb(s)->sb_cp_table,from[i]);
72 	return to;
73 }
74 
hpfs_compare_names(struct super_block * s,const unsigned char * n1,unsigned l1,const unsigned char * n2,unsigned l2,int last)75 int hpfs_compare_names(struct super_block *s,
76 		       const unsigned char *n1, unsigned l1,
77 		       const unsigned char *n2, unsigned l2, int last)
78 {
79 	unsigned l = l1 < l2 ? l1 : l2;
80 	unsigned i;
81 	if (last) return -1;
82 	for (i = 0; i < l; i++) {
83 		unsigned char c1 = upcase(hpfs_sb(s)->sb_cp_table,n1[i]);
84 		unsigned char c2 = upcase(hpfs_sb(s)->sb_cp_table,n2[i]);
85 		if (c1 < c2) return -1;
86 		if (c1 > c2) return 1;
87 	}
88 	if (l1 < l2) return -1;
89 	if (l1 > l2) return 1;
90 	return 0;
91 }
92 
hpfs_is_name_long(const unsigned char * name,unsigned len)93 int hpfs_is_name_long(const unsigned char *name, unsigned len)
94 {
95 	int i,j;
96 	for (i = 0; i < len && name[i] != '.'; i++)
97 		if (no_dos_char(name[i])) return 1;
98 	if (!i || i > 8) return 1;
99 	if (i == len) return 0;
100 	for (j = i + 1; j < len; j++)
101 		if (name[j] == '.' || no_dos_char(name[i])) return 1;
102 	return j - i > 4;
103 }
104 
105 /* OS/2 clears dots and spaces at the end of file name, so we have to */
106 
hpfs_adjust_length(const unsigned char * name,unsigned * len)107 void hpfs_adjust_length(const unsigned char *name, unsigned *len)
108 {
109 	if (!*len) return;
110 	if (*len == 1 && name[0] == '.') return;
111 	if (*len == 2 && name[0] == '.' && name[1] == '.') return;
112 	while (*len && (name[*len - 1] == '.' || name[*len - 1] == ' '))
113 		(*len)--;
114 }
115