This file is indexed.

/usr/include/libkres/nsrep.h is in knot-resolver 1.0.0~beta3-1.

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
/*  Copyright (C) 2014 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 <http://www.gnu.org/licenses/>.
 */

#pragma once

#include <netinet/in.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_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 reputation/QoS tracking.
 */
typedef lru_hash(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 {
		struct sockaddr ip;
		struct sockaddr_in ip4;
		struct sockaddr_in6 ip6;
	} addr[KR_NSREP_MAXADDR];        /**< NS address(es) */
};

/** @internal Address bytes for given family. */
#define kr_nsrep_inaddr(addr) \
	((addr).ip.sa_family == AF_INET ? (void *)&((addr).ip4.sin_addr) : (void *)&((addr).ip6.sin6_addr))
/** @internal Address length for given family. */
#define kr_nsrep_inaddr_len(addr) \
	((addr).ip.sa_family == AF_INET ? sizeof(struct in_addr) : sizeof(struct in6_addr))

/**
 * Set given NS address.
 * @param  qry      updated query
 * @param  addr     address bytes (struct in_addr or struct in6_addr)
 * @param  addr_len address bytes length (type will be derived from this)
 * @return          0 or an error code
 */
KR_EXPORT
int kr_nsrep_set(struct kr_query *qry, uint8_t *addr, size_t addr_len);

/**
 * 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 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
 * @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);

/**
 * 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);