/usr/include/libkres/nsrep.h is in libkres-dev 2.1.1-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 | /* 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/map.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 = KR_CONN_RTT_MAX,
KR_NS_TIMEOUT = (95 * KR_NS_MAX_SCORE) / 100,
KR_NS_LONG = (3 * KR_NS_TIMEOUT) / 4,
KR_NS_UNKNOWN = KR_NS_TIMEOUT / 2,
KR_NS_PENALTY = 100,
KR_NS_GLUED = 10
};
/**
* 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.
*/
enum kr_ns_update_mode {
KR_NS_UPDATE = 0, /**< Update as smooth over last two measurements */
KR_NS_RESET, /**< Set to given value */
KR_NS_ADD, /**< Increment current value */
KR_NS_MAX /**< Set to maximum of current/proposed value. */
};
/**
* NS reputation/QoS 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.
* @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
*/
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 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_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
* @param ns updated kr_nsrep
* @param cache RTT cache
* @return 0 or an error code
* @note ns reputation is zeroed, as KR_NS_NOIP{4,6} flags are useless
* in STUB/FORWARD mode.
*/
KR_EXPORT
int kr_nsrep_sort(struct kr_nsrep *ns, kr_nsrep_lru_t *cache);
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