cuberite/libevent
1
0
Fork 0
mirror of https://github.com/cuberite/libevent.git synced 2025-09-08 11:53:00 -04:00
Code Issues Packages Projects Releases Wiki Activity

DNS: add ttl for negative answers using RFC 2308 idea.

Browse Source
This commit is contained in:
Leonid Evdokimov 2011-08-31 00:56:45 +04:00 committed by Nick Mathewson
parent a718b6c31c
commit f72e8f6643
1 changed files with 36 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

42
evdns.c
View File

@ -133,6 +133,7 @@
#define TYPE_A EVDNS_TYPE_A
#define TYPE_CNAME 5
#define TYPE_PTR EVDNS_TYPE_PTR
#define TYPE_SOA EVDNS_TYPE_SOA
#define TYPE_AAAA EVDNS_TYPE_AAAA
#define CLASS_INET EVDNS_CLASS_INET
@ -760,7 +761,7 @@ reply_run_callback(struct deferred_cb *d, void *user_pointer)
cb->reply.data.a.addresses,
user_pointer);
else
cb->user_callback(cb->err, 0, 0, 0, NULL, user_pointer);
cb->user_callback(cb->err, 0, 0, cb->ttl, NULL, user_pointer);
break;
case TYPE_PTR:
if (cb->have_reply) {
@ -768,7 +769,7 @@ reply_run_callback(struct deferred_cb *d, void *user_pointer)
cb->user_callback(DNS_ERR_NONE, DNS_PTR, 1, cb->ttl,
&name, user_pointer);
} else {
cb->user_callback(cb->err, 0, 0, 0, NULL, user_pointer);
cb->user_callback(cb->err, 0, 0, cb->ttl, NULL, user_pointer);
}
break;
case TYPE_AAAA:
@ -778,7 +779,7 @@ reply_run_callback(struct deferred_cb *d, void *user_pointer)
cb->reply.data.aaaa.addresses,
user_pointer);
else
cb->user_callback(cb->err, 0, 0, 0, NULL, user_pointer);
cb->user_callback(cb->err, 0, 0, cb->ttl, NULL, user_pointer);
break;
default:
EVUTIL_ASSERT(0);
@ -895,7 +896,7 @@ reply_handle(struct request *const req, u16 flags, u32 ttl, struct reply *reply)
}
/* all else failed. Pass the failure up */
reply_schedule_callback(req, 0, error, NULL);
reply_schedule_callback(req, ttl, error, NULL);
request_finished(req, &REQ_HEAD(req->base, req->trans_id), 1);
} else {
/* all ok, tell the user */
@ -998,8 +999,8 @@ reply_parse(struct evdns_base *base, u8 *packet, int length) {
/* If it's not an answer, it doesn't correspond to any request. */
if (!(flags & 0x8000)) return -1; /* must be an answer */
if (flags & 0x020f) {
/* there was an error */
if ((flags & 0x020f) && (flags & 0x020f) != DNS_ERR_NOTEXIST) {
/* there was an error and it's not NXDOMAIN */
goto err;
}
/* if (!answers) return; */ /* must have an answer of some form */
@ -1121,6 +1122,35 @@ reply_parse(struct evdns_base *base, u8 *packet, int length) {
}
}
if (!reply.have_answer) {
for (i = 0; i < authority; ++i) {
u16 type, class;
SKIP_NAME;
GET16(type);
GET16(class);
GET32(ttl);
GET16(datalength);
if (type == TYPE_SOA && class == CLASS_INET) {
u32 serial, refresh, retry, expire, minimum;
SKIP_NAME;
SKIP_NAME;
GET32(serial);
GET32(refresh);
GET32(retry);
GET32(expire);
GET32(minimum);
ttl_r = MIN(ttl_r, ttl);
ttl_r = MIN(ttl_r, minimum);
} else {
/* skip over any other type of resource */
j += datalength;
}
}
}
if (ttl_r == 0xffffffff)
ttl_r = 0;
reply_handle(req, flags, ttl_r, &reply);
return 0;
err: