Switch from using array references to using pointers to refer to the
pathname characters as they get generated. Also limit the scope of
a few automatic variables.
Signed-off-by: Alex Elder <aelder@xxxxxxx>
The only update since the last post version is the addition of an
ASSERT() in the loop generating the last 5 bytes.
---
db/metadump.c | 35 +++++++++++++++++++----------------
1 file changed, 19 insertions(+), 16 deletions(-)
Index: b/db/metadump.c
===================================================================
--- a/db/metadump.c
+++ b/db/metadump.c
@@ -437,11 +437,8 @@ generate_obfuscated_name(
{
xfs_dahash_t hash;
name_ent_t *p;
- int i;
int dup;
- xfs_dahash_t newhash;
uchar_t newname[NAME_MAX];
- uchar_t *newp = &newname[0];
/*
* Our obfuscation algorithm requires at least 5-character
@@ -472,7 +469,12 @@ generate_obfuscated_name(
hash = libxfs_da_hashname(name, namelen);
do {
- uchar_t high_bit;
+ int i;
+ xfs_dahash_t newhash = 0;
+ uchar_t *newp = &newname[0];
+ uchar_t *first;
+ uchar_t high_bit;
+ int shift;
dup = 0;
@@ -482,10 +484,10 @@ generate_obfuscated_name(
* characters. Accumulate its new hash value as we
* go.
*/
- newhash = 0;
for (i = 0; i < namelen - 5; i++) {
- newp[i] = random_filename_char();
- newhash = newp[i] ^ rol32(newhash, 7);
+ *newp = random_filename_char();
+ newhash = *newp ^ rol32(newhash, 7);
+ newp++;
}
/*
@@ -500,16 +502,17 @@ generate_obfuscated_name(
*/
newhash = rol32(newhash, 3) ^ hash;
+ first = newp;
high_bit = 0;
- for (i = 5; i > 0; i--) {
- int shift = (i - 1) * 7;
-
- newp[namelen - i] = ((newhash >> shift) & 0x7f) ^ high_bit;
- if (is_invalid_char(newp[namelen - i])) {
- newp[namelen - i] ^= 1;
+ for (shift = 28; shift >= 0; shift -= 7) {
+ *newp = (newhash >> shift & 0x7f) ^ high_bit;
+ if (is_invalid_char(*newp)) {
+ *newp ^= 1;
high_bit = 0x80;
} else
high_bit = 0;
+ ASSERT(!is_invalid_char(*newp));
+ newp++;
}
/*
@@ -522,15 +525,15 @@ generate_obfuscated_name(
* worry about it becoming invalid as a result.
*/
if (high_bit) {
- newp[namelen - 5] ^= 0x10;
- ASSERT(!is_invalid_char(newp[namelen - 5]));
+ *first ^= 0x10;
+ ASSERT(!is_invalid_char(*first));
}
ASSERT(libxfs_da_hashname(newname, namelen) == hash);
for (p = nametable[hash % NAME_TABLE_SIZE]; p; p = p->next) {
if (p->hash == hash && p->namelen == namelen &&
- memcmp(p->name, newname, namelen) == 0){
+ !memcmp(p->name, newname, namelen)) {
dup = 1;
break;
}
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