Adding upstream version 3.2.1.upstream/3.2.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 188 insertions, 0 deletions

diff --git a/lib/nsrep.h b/lib/nsrep.h
new file mode 100644
index 0000000..cc35ca4
--- /dev/null
+++ b/lib/nsrep.h
@@ -0,0 +1,188 @@
+/*  Copyright (C) 2014-2017 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <netinet/in.h>
+#include <sys/socket.h>
+#include <libknot/dname.h>
+#include <limits.h>
+
+#include "lib/defines.h"
+#include "lib/generic/lru.h"
+
+struct kr_query;
+
+/** 
+  * NS RTT score (special values).
+  * @note RTT is measured in milliseconds.
+  */
+enum kr_ns_score {
+	KR_NS_MAX_SCORE     = 20 * KR_CONN_RTT_MAX, /* max possible value */
+	KR_NS_FWD_TIMEOUT   = (95 * 10000) / 100, /* timeout for upstream recursor,
+						   * 95 percents from max resolution time */
+	KR_NS_TIMEOUT       = (95 * KR_CONN_RTT_MAX) / 100, /* timeout for upstream auth */
+	KR_NS_LONG          = (3 * KR_NS_TIMEOUT) / 4,
+	KR_NS_UNKNOWN       = KR_NS_TIMEOUT / 2,
+	KR_NS_PENALTY       = 100,
+	KR_NS_GLUED         = 10
+};
+
+/**
+ *  See kr_nsrep_update_rtt()
+ */
+#define KR_NS_DEAD (((KR_NS_TIMEOUT * 4) + 3) / 3)
+#define KR_NS_FWD_DEAD (((KR_NS_FWD_TIMEOUT * 4) + 3) / 3)
+
+/** If once NS was marked as "timeouted", it won't participate in NS elections
+ * at least KR_NS_TIMEOUT_RETRY_INTERVAL milliseconds (now: one second). */
+#define KR_NS_TIMEOUT_RETRY_INTERVAL 1000
+
+/**
+ * NS QoS flags.
+ */
+enum kr_ns_rep {
+	KR_NS_NOIP4  = 1 << 0, /**< NS has no IPv4 */
+	KR_NS_NOIP6  = 1 << 1, /**< NS has no IPv6 */
+	KR_NS_NOEDNS = 1 << 2  /**< NS has no EDNS support */
+};
+
+/**
+ * NS RTT update modes.
+ * First update is always KR_NS_RESET unless
+ * KR_NS_UPDATE_NORESET mode had choosen.
+ */
+enum kr_ns_update_mode {
+	KR_NS_UPDATE = 0,     /**< Update as smooth over last two measurements */
+	KR_NS_UPDATE_NORESET, /**< Same as KR_NS_UPDATE, but disable fallback to
+			       *   KR_NS_RESET on newly added entries.
+			       *   Zero is used as initial value. */
+	KR_NS_RESET,          /**< Set to given value */
+	KR_NS_ADD,            /**< Increment current value */
+	KR_NS_MAX             /**< Set to maximum of current/proposed value. */
+};
+
+struct kr_nsrep_rtt_lru_entry {
+	unsigned score;	          /* combined rtt */
+	uint64_t tout_timestamp;  /* The time when score became
+				   * greater or equal then KR_NS_TIMEOUT.
+				   * Is meaningful only when score >= KR_NS_TIMEOUT */
+};
+
+typedef struct kr_nsrep_rtt_lru_entry kr_nsrep_rtt_lru_entry_t;
+
+/**
+ * NS QoS tracking.
+ */
+typedef lru_t(kr_nsrep_rtt_lru_entry_t) kr_nsrep_rtt_lru_t;
+
+/**
+ * NS reputation tracking.
+ */
+typedef lru_t(unsigned) kr_nsrep_lru_t;
+
+/* Maximum count of addresses probed in one go (last is left empty) */
+#define KR_NSREP_MAXADDR 4
+
+/**
+ * Name server representation.
+ * Contains extra information about the name server, e.g. score
+ * or other metadata.
+ */
+struct kr_nsrep
+{
+	unsigned score;                  /**< NS score */
+	unsigned reputation;             /**< NS reputation */
+	const knot_dname_t *name;        /**< NS name */
+	struct kr_context *ctx;          /**< Resolution context */
+	union inaddr addr[KR_NSREP_MAXADDR];        /**< NS address(es) */
+};
+
+/**
+ * Set given NS address.  (Very low-level access to the list.)
+ * @param  qry      updated query
+ * @param  index    index of the updated target
+ * @param  sock     socket address to use (sockaddr_in or sockaddr_in6 or NULL)
+ * @return          0 or an error code, in particular kr_error(ENOENT) for net.ipvX
+ */
+KR_EXPORT
+int kr_nsrep_set(struct kr_query *qry, size_t index, const struct sockaddr *sock);
+
+/**
+ * Elect best nameserver/address pair from the nsset.
+ * @param  qry          updated query
+ * @param  ctx          resolution context
+ * @return              0 or an error code
+ */
+KR_EXPORT
+int kr_nsrep_elect(struct kr_query *qry, struct kr_context *ctx);
+
+/**
+ * Elect best nameserver/address pair from the nsset.
+ * @param  qry          updated query
+ * @param  ctx          resolution context
+ * @return              0 or an error code
+ */
+KR_EXPORT
+int kr_nsrep_elect_addr(struct kr_query *qry, struct kr_context *ctx);
+
+/**
+ * Update NS address RTT information.
+ *
+ * @brief In KR_NS_UPDATE mode reputation is smoothed over last N measurements.
+ * 
+ * @param  ns           updated NS representation
+ * @param  addr         chosen address (NULL for first)
+ * @param  score        new score (i.e. RTT), see enum kr_ns_score
+ * @param  cache        RTT LRU cache
+ * @param  umode        update mode (KR_NS_UPDATE or KR_NS_RESET or KR_NS_ADD)
+ * @return              0 on success, error code on failure
+ */
+KR_EXPORT
+int kr_nsrep_update_rtt(struct kr_nsrep *ns, const struct sockaddr *addr,
+			unsigned score, kr_nsrep_rtt_lru_t *cache, int umode);
+
+/**
+ * Update NSSET reputation information.
+ * 
+ * @param  ns           updated NS representation
+ * @param  reputation   combined reputation flags, see enum kr_ns_rep
+ * @param  cache        LRU cache
+ * @return              0 on success, error code on failure
+ */
+KR_EXPORT
+int kr_nsrep_update_rep(struct kr_nsrep *ns, unsigned reputation, kr_nsrep_lru_t *cache);
+/**
+ * Copy NSSET reputation information and resets score.
+ *
+ * @param  dst          updated NS representation
+ * @param  src          source NS representation
+ * @return              0 on success, error code on failure
+ */
+int kr_nsrep_copy_set(struct kr_nsrep *dst, const struct kr_nsrep *src);
+
+/**
+ * Sort addresses in the query nsrep list by cached RTT.
+ * if RTT is greater then KR_NS_TIMEOUT, address will placed at the beginning of the
+ * nsrep list once in cache.ns_tout() milliseconds. Otherwise it will be sorted
+ * as if it has cached RTT equal to KR_NS_MAX_SCORE + 1.
+ * @param  ns           updated kr_nsrep
+ * @param  ctx          name resolution context.
+ * @return              0 or an error code
+ * @note   ns reputation is zeroed and score is set to KR_NS_MAX_SCORE + 1.
+ */
+KR_EXPORT
+int kr_nsrep_sort(struct kr_nsrep *ns,  struct kr_context *ctx);