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/* Copyright (c) 2014, Vsevolod Stakhov
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED ''AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef DNS_PRIVATE_H_
#define DNS_PRIVATE_H_
#include "config.h"
#define MAX_SERVERS 16
/* Upstream timeouts */
#define DEFAULT_UPSTREAM_ERROR_TIME 10
#define DEFAULT_UPSTREAM_DEAD_TIME 300
#define DEFAULT_UPSTREAM_MAXERRORS 10
static const unsigned base = 36;
static const unsigned t_min = 1;
static const unsigned t_max = 26;
static const unsigned skew = 38;
static const unsigned damp = 700;
static const unsigned initial_n = 128;
static const unsigned initial_bias = 72;
static const gint dns_port = 53;
#define UDP_PACKET_SIZE 4096
#define DNS_COMPRESSION_BITS 0xC0
#define DNS_D_MAXLABEL 63 /* + 1 '\0' */
#define DNS_D_MAXNAME 255 /* + 1 '\0' */
#define RESOLV_CONF "/etc/resolv.conf"
/**
* Represents DNS server
*/
struct rspamd_dns_server {
struct upstream up; /**< upstream structure */
gchar *name; /**< name of DNS server */
struct rspamd_dns_io_channel *io_channels;
struct rspamd_dns_io_channel *cur_io_channel;
};
/**
* IO channel for a specific DNS server
*/
struct rspamd_dns_io_channel {
struct rspamd_dns_server *srv;
struct rspamd_dns_resolver *resolver;
gint sock; /**< persistent socket */
struct event ev;
GHashTable *requests; /**< requests in flight */
struct rspamd_dns_io_channel *prev, *next;
};
struct rspamd_dns_resolver {
struct rspamd_dns_server servers[MAX_SERVERS];
gint servers_num; /**< number of DNS servers registered */
guint request_timeout;
guint max_retransmits;
guint max_errors;
GHashTable *io_channels; /**< hash of io chains indexed by socket */
gboolean throttling; /**< dns servers are busy */
gboolean is_master_slave; /**< if this is true, then select upstreams as master/slave */
guint errors; /**< resolver errors */
struct timeval throttling_time; /**< throttling time */
struct event throttling_event; /**< throttling event */
struct event_base *ev_base; /**< base for event ops */
};
struct dns_header;
struct dns_query;
/* Internal DNS structs */
struct dns_header {
guint qid :16;
#if BYTE_ORDER == BIG_ENDIAN
guint qr:1;
guint opcode:4;
guint aa:1;
guint tc:1;
guint rd:1;
guint ra:1;
guint unused:3;
guint rcode:4;
#else
guint rd :1;
guint tc :1;
guint aa :1;
guint opcode :4;
guint qr :1;
guint rcode :4;
guint unused :3;
guint ra :1;
#endif
guint qdcount :16;
guint ancount :16;
guint nscount :16;
guint arcount :16;
};
enum dns_section {
DNS_S_QD = 0x01,
#define DNS_S_QUESTION DNS_S_QD
DNS_S_AN = 0x02,
#define DNS_S_ANSWER DNS_S_AN
DNS_S_NS = 0x04,
#define DNS_S_AUTHORITY DNS_S_NS
DNS_S_AR = 0x08,
#define DNS_S_ADDITIONAL DNS_S_AR
DNS_S_ALL = 0x0f
};
/* enum dns_section */
enum dns_opcode {
DNS_OP_QUERY = 0,
DNS_OP_IQUERY = 1,
DNS_OP_STATUS = 2,
DNS_OP_NOTIFY = 4,
DNS_OP_UPDATE = 5,
};
/* dns_opcode */
enum dns_class {
DNS_C_IN = 1,
DNS_C_ANY = 255
};
/* enum dns_class */
struct dns_query {
gchar *qname;
guint qtype :16;
guint qclass :16;
};
enum dns_type {
DNS_T_A = 1,
DNS_T_NS = 2,
DNS_T_CNAME = 5,
DNS_T_SOA = 6,
DNS_T_PTR = 12,
DNS_T_MX = 15,
DNS_T_TXT = 16,
DNS_T_AAAA = 28,
DNS_T_SRV = 33,
DNS_T_OPT = 41,
DNS_T_SSHFP = 44,
DNS_T_SPF = 99,
DNS_T_ALL = 255
};
/* enum dns_type */
static const gchar dns_rcodes[16][16] = {
[DNS_RC_NOERROR] = "NOERROR",
[DNS_RC_FORMERR] = "FORMERR",
[DNS_RC_SERVFAIL] = "SERVFAIL",
[DNS_RC_NXDOMAIN] = "NXDOMAIN",
[DNS_RC_NOTIMP] = "NOTIMP",
[DNS_RC_REFUSED] = "REFUSED",
[DNS_RC_YXDOMAIN] = "YXDOMAIN",
[DNS_RC_YXRRSET] = "YXRRSET",
[DNS_RC_NXRRSET] = "NXRRSET",
[DNS_RC_NOTAUTH] = "NOTAUTH",
[DNS_RC_NOTZONE] = "NOTZONE",
};
static const gchar dns_types[7][16] = {
[DNS_REQUEST_A] = "A request",
[DNS_REQUEST_PTR] = "PTR request",
[DNS_REQUEST_MX] = "MX request",
[DNS_REQUEST_TXT] = "TXT request",
[DNS_REQUEST_SRV] = "SRV request",
[DNS_REQUEST_SPF] = "SPF request",
[DNS_REQUEST_AAA] = "AAA request"
};
#endif /* DNS_PRIVATE_H_ */
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