From 7b7775ac08963d882b902c70fddd9b908d900804 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Vladim=C3=ADr=20=C4=8Cun=C3=A1t?= <vladimir.cunat@nic.cz>
Date: Thu, 25 Jan 2018 17:39:10 +0100
Subject: [PATCH] cache: try also CNAME wildcard
I somehow forgot that case. Unfortunately the cache optimization for
CNAMEs doesn't help this case, so we just do (up to) two probes.
---
lib/cache.c | 107 ++++++++++++++++++++++++++++++++--------------------
1 file changed, 67 insertions(+), 40 deletions(-)
diff --git a/lib/cache.c b/lib/cache.c
index e7c814955..f85b48ea8 100644
--- a/lib/cache.c
+++ b/lib/cache.c
@@ -296,6 +296,9 @@ static knot_db_val_t closest_NS(kr_layer_t *ctx, struct key *k);
static int answer_simple_hit(kr_layer_t *ctx, knot_pkt_t *pkt, uint16_t type,
const struct entry_h *eh, const void *eh_bound, uint32_t new_ttl);
static int cache_peek_real(kr_layer_t *ctx, knot_pkt_t *pkt);
+static int try_wild(struct key *k, struct answer *ans, const knot_dname_t *clencl_name,
+ const uint16_t type, const uint8_t lowest_rank,
+ const struct kr_query *qry, struct kr_cache *cache);
/** function for .produce phase */
int cache_peek(kr_layer_t *ctx, knot_pkt_t *pkt)
@@ -313,6 +316,7 @@ int cache_peek(kr_layer_t *ctx, knot_pkt_t *pkt)
return ret;
}
+
/**
* \note we don't transition to KR_STATE_FAIL even in case of "unexpected errors".
*/
@@ -504,49 +508,19 @@ static int cache_peek_real(kr_layer_t *ctx, knot_pkt_t *pkt)
assert(!ret);
return ctx->state;
}
- knot_db_val_t key = key_exact_type(k, qry->stype);
- /* Find the record. */
- knot_db_val_t val = { NULL, 0 };
- ret = cache_op(cache, read, &key, &val, 1);
- if (!ret) {
- ret = entry_h_seek(&val, qry->stype);
- }
- if (ret) {
- if (ret != -abs(ENOENT)) {
- VERBOSE_MSG(qry, "=> wildcard: hit error %d %s\n",
- ret, strerror(abs(ret)));
+ const uint16_t types[] = { qry->stype, KNOT_RRTYPE_CNAME };
+ for (int i = 0; i < (2 - (qry->stype == KNOT_RRTYPE_CNAME)); ++i) {
+ ret = try_wild(k, &ans, clencl_name, types[i],
+ lowest_rank, qry, cache);
+ if (ret == kr_ok()) {
+ break;
+ } else if (ret != -ABS(ENOENT) && ret != -ABS(ESTALE)) {
assert(false);
+ return ctx->state;
}
- WITH_VERBOSE(qry) {
- auto_free char *clencl_str = kr_dname_text(clencl_name);
- VERBOSE_MSG(qry, "=> wildcard: not found: *.%s\n",
- clencl_str);
- }
- return ctx->state;
+ /* else continue */
}
- /* Check if the record is OK. */
- const struct entry_h *eh = entry_h_consistent(val, qry->stype);
- if (!eh) {
- assert(false);
- return ctx->state;
- // LATER: recovery in case of error, perhaps via removing the entry?
- }
- int32_t new_ttl = get_new_ttl(eh, qry, qry->sname, qry->stype);
- /* ^^ here we use the *expanded* wildcard name */
- if (new_ttl < 0 || eh->rank < lowest_rank || eh->is_packet) {
- /* Wildcard record with stale TTL, bad rank or packet. */
- VERBOSE_MSG(qry, "=> wildcard: skipping %s, rank 0%.2o, new TTL %d\n",
- eh->is_packet ? "packet" : "RR", eh->rank, new_ttl);
- return ctx->state;
- }
- /* Add the RR into the answer. */
- const void *eh_bound = val.data + val.len;
- ret = entry2answer(&ans, AR_ANSWER, eh, eh_bound,
- qry->sname, qry->stype, new_ttl);
- VERBOSE_MSG(qry, "=> NSEC wildcard: answer expanded, ret = %d, new TTL %d\n",
- ret, (int)new_ttl);
- if (ret) return ctx->state;
- ans.rcode = PKT_NOERROR;
+ if (ret) return ctx->state; /* neither attempt succeeded */
}
@@ -917,6 +891,59 @@ static int found_exact_hit(kr_layer_t *ctx, knot_pkt_t *pkt, knot_db_val_t val,
}
}
+
+/** Try to satisfy via wildcard. See the single call site. */
+static int try_wild(struct key *k, struct answer *ans, const knot_dname_t *clencl_name,
+ const uint16_t type, const uint8_t lowest_rank,
+ const struct kr_query *qry, struct kr_cache *cache)
+{
+ knot_db_val_t key = key_exact_type(k, type);
+ /* Find the record. */
+ knot_db_val_t val = { NULL, 0 };
+ int ret = cache_op(cache, read, &key, &val, 1);
+ if (!ret) {
+ ret = entry_h_seek(&val, type);
+ }
+ if (ret) {
+ if (ret != -ABS(ENOENT)) {
+ VERBOSE_MSG(qry, "=> wildcard: hit error %d %s\n",
+ ret, strerror(abs(ret)));
+ assert(false);
+ }
+ WITH_VERBOSE(qry) {
+ auto_free char *clencl_str = kr_dname_text(clencl_name),
+ *type_str = kr_rrtype_text(type);
+ VERBOSE_MSG(qry, "=> wildcard: not found: *.%s %s\n",
+ clencl_str, type_str);
+ }
+ return ret;
+ }
+ /* Check if the record is OK. */
+ const struct entry_h *eh = entry_h_consistent(val, type);
+ if (!eh) {
+ assert(false);
+ return kr_error(ret);
+ // LATER: recovery in case of error, perhaps via removing the entry?
+ }
+ int32_t new_ttl = get_new_ttl(eh, qry, qry->sname, type);
+ /* ^^ here we use the *expanded* wildcard name */
+ if (new_ttl < 0 || eh->rank < lowest_rank || eh->is_packet) {
+ /* Wildcard record with stale TTL, bad rank or packet. */
+ VERBOSE_MSG(qry, "=> wildcard: skipping %s, rank 0%.2o, new TTL %d\n",
+ eh->is_packet ? "packet" : "RR", eh->rank, new_ttl);
+ return -ABS(ESTALE);
+ }
+ /* Add the RR into the answer. */
+ const void *eh_bound = val.data + val.len;
+ ret = entry2answer(ans, AR_ANSWER, eh, eh_bound, qry->sname, type, new_ttl);
+ VERBOSE_MSG(qry, "=> NSEC wildcard: answer expanded, ret = %d, new TTL %d\n",
+ ret, (int)new_ttl);
+ if (ret) return kr_error(ret);
+ ans->rcode = PKT_NOERROR;
+ return kr_ok();
+}
+
+
static int peek_exact_real(struct kr_cache *cache, const knot_dname_t *name, uint16_t type,
struct kr_cache_p *peek)
{
--
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