udhcp: fix DNS domanin codec bug: bad compression flag checks
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
parent
651a2697f7
commit
a14a9d73b1
@ -44,14 +44,14 @@ char* FAST_FUNC dname_dec(const uint8_t *cstr, int clen, const char *pre)
|
||||
while (crtpos < clen) {
|
||||
c = cstr + crtpos;
|
||||
|
||||
if (*c & NS_CMPRSFLGS) {
|
||||
if ((*c & NS_CMPRSFLGS) == NS_CMPRSFLGS) {
|
||||
/* pointer */
|
||||
if (crtpos + 2 > clen) /* no offset to jump to? abort */
|
||||
return NULL;
|
||||
if (retpos == 0) /* toplevel? save return spot */
|
||||
retpos = crtpos + 2;
|
||||
depth++;
|
||||
crtpos = ((c[0] & 0x3f) << 8) | (c[1] & 0xff); /* jump */
|
||||
crtpos = ((c[0] & 0x3f) << 8) | c[1]; /* jump */
|
||||
} else if (*c) {
|
||||
/* label */
|
||||
if (crtpos + *c + 1 > clen) /* label too long? abort */
|
||||
@ -154,7 +154,7 @@ static int find_offset(const uint8_t *cstr, int clen, const uint8_t *dname)
|
||||
while (off < clen) {
|
||||
c = cstr + off;
|
||||
|
||||
if ((*c & NS_CMPRSFLGS) != 0) { /* pointer, skip */
|
||||
if ((*c & NS_CMPRSFLGS) == NS_CMPRSFLGS) { /* pointer, skip */
|
||||
off += 2;
|
||||
} else if (*c) { /* label, try matching dname */
|
||||
inc = *c + 1;
|
||||
@ -164,8 +164,8 @@ static int find_offset(const uint8_t *cstr, int clen, const uint8_t *dname)
|
||||
return off;
|
||||
d += *c + 1;
|
||||
c += *c + 1;
|
||||
if ((*c & NS_CMPRSFLGS) != 0) /* pointer, jump */
|
||||
c = cstr + (((*c & 0x3f) << 8) | (*(c + 1) & 0xff));
|
||||
if ((*c & NS_CMPRSFLGS) == NS_CMPRSFLGS) /* pointer, jump */
|
||||
c = cstr + (((c[0] & 0x3f) << 8) | c[1]);
|
||||
}
|
||||
off += inc;
|
||||
} else { /* null, skip */
|
||||
@ -196,7 +196,7 @@ uint8_t* FAST_FUNC dname_enc(const uint8_t *cstr, int clen, const char *src, int
|
||||
for (d = dname; *d != 0; d += *d + 1) {
|
||||
off = find_offset(cstr, clen, d);
|
||||
if (off >= 0) { /* found a match, add pointer and terminate string */
|
||||
*d++ = NS_CMPRSFLGS;
|
||||
*d++ = NS_CMPRSFLGS + (off >> 8);
|
||||
*d = off;
|
||||
break;
|
||||
}
|
||||
|
Loading…
Reference in New Issue
Block a user