Make the DNS resolver accept domain names with an underscore.

More precisely, this accepts domain labels with an underscore in
the middle (i.e. not at the start or the end of the label). This
is needed to perform complex CNAME chain resolution in certain
VPN networks.
This commit is contained in:
David 'Digit' Turner 2009-07-27 19:19:29 +02:00
parent 39f3745cf3
commit 3773d35eb9

View File

@ -147,6 +147,12 @@ dn_skipname(const u_char *ptr, const u_char *eom) {
* tell us anything about network-format data. The rest of the BIND system
* is not careful about this, but for some reason, we're doing it right here.
*/
/* BIONIC: We also accept underscores in the middle of labels.
* This extension is needed to make resolution on some VPN networks
* work properly.
*/
#define PERIOD 0x2e
#define hyphenchar(c) ((c) == 0x2d)
#define bslashchar(c) ((c) == 0x5c)
@ -155,9 +161,10 @@ dn_skipname(const u_char *ptr, const u_char *eom) {
#define alphachar(c) (((c) >= 0x41 && (c) <= 0x5a) \
|| ((c) >= 0x61 && (c) <= 0x7a))
#define digitchar(c) ((c) >= 0x30 && (c) <= 0x39)
#define underscorechar(c) ((c) == 0x5f)
#define borderchar(c) (alphachar(c) || digitchar(c))
#define middlechar(c) (borderchar(c) || hyphenchar(c))
#define middlechar(c) (borderchar(c) || hyphenchar(c) || underscorechar(c))
#define domainchar(c) ((c) > 0x20 && (c) < 0x7f)
int